Sludge compression molding hydraulic machine and intelligent control process thereof

Abstract

The invention relates to the technical field of hydraulic machines, in particular to a sludge compression molding hydraulic machine and an intelligent control process thereof. The hydraulic system comprises a plurality of main cylinders and multi-stage ejection lower cylinders, and the main cylinders penetrate through the upper cross beam and are connected with the sliding blocks; the multi-stage ejection lower cylinder is arranged in a foundation, and a displacement sensor is arranged on the guide rod and used for monitoring the stroke displacement of the up-down movement of the sliding block; a liquid filling tank is communicated with the main cylinder through an electromagnetic valve, and a magnetic filter and an oil temperature control system are arranged in an oil tank; the intelligent control system is integrated in a power distribution cabinet, and pressing parameters are set through a mobile operation table, the intelligent sludge pressing forming hydraulic machine and the control technology are provided, the manual trial and error cost is reduced, and an efficient and energy-saving solution is provided for sludge resource utilization.

Description

Technical Field

[0001] This invention relates to the field of hydraulic press technology, and in particular to a sludge pressing and molding hydraulic press and its intelligent control process. Background Technology

[0002] With the acceleration of urbanization and increasingly stringent environmental protection requirements, sludge treatment has become an important issue in the field of environmental engineering. In traditional sludge treatment technologies, mechanical dewatering and pressing are commonly used methods, but existing hydraulic equipment has significant shortcomings in terms of efficiency, energy consumption, and intelligence. For example, conventional hydraulic presses mostly use a single-stage hydraulic cylinder structure, with limited output pressure (usually below 30MPa), resulting in low sludge density, difficulty in effectively reducing moisture content, and a tendency for the pressed blank to become loose or cracked. Furthermore, traditional equipment relies on fixed pressing parameters and cannot dynamically adjust the process according to sludge characteristics (such as moisture content and density), leading to high energy consumption, poor product consistency, and insufficient control precision and response speed in the hydraulic system, especially during the pressure holding stage where pressure decay is prone to occur, requiring manual intervention to replenish pressure and affecting the level of automation. Inaccurate resistance prediction during the demolding process often leads to mold damage or breakage of the molded body. At the same time, the lack of real-time monitoring and self-checking functions for the hydraulic system status (such as leakage and oil cleanliness) results in high equipment maintenance costs and frequent downtime due to malfunctions.

[0003] To address the aforementioned issues, this patent proposes a sludge compression molding hydraulic press and its intelligent control process. Through innovative structural design (such as a three-beam, four-column body and a stepped, multi-stage ejector lower cylinder) integrated with an intelligent control system, it achieves high-pressure output (≥50MPa), dynamic parameter adjustment, and process optimization. Key technologies such as real-time compression force calculation based on sludge moisture content, closed-loop control using magnetostrictive displacement sensors, and a PLC-integrated self-testing module significantly improve the equipment's accuracy and reliability. Furthermore, the mobile control panel incorporates a process database and adaptive algorithms to recommend optimal compression parameters, reducing manual trial-and-error costs and providing an efficient and energy-saving solution for sludge resource utilization. Summary of the Invention

[0004] The purpose of this invention is to solve the problems existing in the prior art by proposing a sludge pressing and molding hydraulic press and its intelligent control process.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a sludge pressing and molding hydraulic press, comprising: a three-beam four-column machine body installed on a foundation, wherein the three-beam four-column machine body includes an upper crossbeam, a lower crossbeam, a slider and four guide rods, the four guide rods respectively pass through the upper crossbeam and are slidably connected to the slider located at the lower end of the upper crossbeam, and the upper crossbeam and the lower crossbeam are connected by a support rod; Hydraulic system: includes multiple main cylinders and multi-stage ejector cylinders. The main cylinders pass through the upper crossbeam and are connected to the slider. The multi-stage ejector cylinders are installed in the foundation and adopt a stepped piston structure. Displacement sensors are installed on the guide rod to monitor the stroke displacement of the slider's up and down movement. Filling and oil tank system: The filling tank is connected to the main cylinders through a solenoid valve. The oil tank has a built-in magnetic filter and oil temperature control system. Intelligent control system: Integrated into the power distribution cabinet, it allows setting of pressing parameters via a mobile control panel and real-time calculation of pressing force F based on sludge moisture content ω0. Where α is the compaction coefficient, ρ is the sludge density, V is the single feeding volume, and A 模具 This represents the projected area of ​​the mold.

[0006] Furthermore, the piston diameter of the multi-stage ejector cylinder is designed in a proportional sequence, with the ejection ratio increasing by k for each stage, and the ejection force of the final stage... Where k>1, n is the series, and p1 is the primary top output force.

[0007] Furthermore, the sealing structure of the main cylinder includes a piston rod seal and a cylinder port, with a double dustproof ring provided at the cylinder port; the displacement sensor detects the slider displacement feedback data and sends it to the PLC, and the PLC dynamically adjusts the pressing speed of the main cylinder based on a proportional-integral-derivative (PID) control algorithm, specifically: (1) Calculate the current displacement deviation: e=S 设定 -S 当前 ; (2) Based on the displacement deviation e, calculate the speed adjustment Δv using the PID control algorithm: Δv = Kp·e + Ki·∫e dt + Kd·(de / dt), where Kp is the proportionality coefficient, Ki is the integral coefficient, and Kd is the differential coefficient. (3) Adjust the current suppression speed to: v 新 =v 当前 +Δv, where the output Δv of the PID control algorithm is proportional to the displacement deviation e, the cumulative amount of the deviation, and the rate of change of the deviation.

[0008] A hydraulic press for sludge pressing and molding process, comprising any of the above-described sludge pressing and molding hydraulic presses, wherein the steps of the sludge pressing and molding process include: S1. Sludge conveying: After the sludge feeding device feeds the sludge into the mold, the mold containing the sludge is conveyed to the pressing table of the hydraulic forming press via the track. S2, Rapid Descent: The slider descends to the mold surface; S3, Pressing: The slider presses the set pressure value. Alternatively, the set termination stroke S can be used for suppression; S4, Pressure Holding: Pressure holding time Where γ is the sludge coefficient, calibrated experimentally, with a value ranging from 0.3 to 2.0 mm⁻¹; h 污泥 This represents the initial thickness of the sludge inside the mold, in mm. This represents the proportional relationship between sludge compression or pressure change, where ω is the moisture content correction factor, and 1 < ω ≤ 2; S5. Pressure relief: Two-stage pressure relief, first to ≤5 MPa, then to ≤0.5 MPa; S6, Return: The slider returns to its initial position; S7. Ejection and Demolding: The multi-stage ejection cylinder ejects the pressed sludge and demolds it.

[0009] Furthermore, S4 and pressure holding also include pressure replenishment. Pressure replenishment is triggered when the pressure loss ratio ΔP ≥ 5%. The condition for triggering pressure replenishment is as follows: The number of repressurization cycles is ≤3, and the time for each repressurization cycle is ≤2 seconds. The pressure loss ratio represents the initial pressure P during the pressure holding phase. 初始 Real-time pressure P monitored during the pressing process 实时 The relative difference.

[0010] Furthermore, the mobile operating console includes a storage unit and a processor. The storage unit has a built-in process database and supports the calculation of the optimal pressing speed v using the following formula. 最优 : Where k is a dimensionless comprehensive empirical coefficient, 100 ≤ k ≤ 850, determined by fitting historical process data; E 污泥 The elastic modulus of sludge is expressed in Pa; h. 污泥 F represents the initial thickness of the sludge inside the mold, in mm. 模 The unit for estimating the release force is N.

[0011] Furthermore, the PLC control program integrates a self-test module, which performs the following self-tests using pressure sensors, displacement sensors, and proportional valves: (1) Hydraulic system leakage detection: shut down all actuators, start the hydraulic pump and maintain the test pressure P 测试 Measure the pressure drop per unit time ΔP / Δt, according to Q. 泄露 = (ΔP / Δt) · V 系统 / E 油液 Calculate the leakage flow rate, V 系统 For a hydraulically enclosed volume, the system's elastic modulus E is used. 油液 Converted to leaked traffic, if Q 泄露 ≥ 0.1%·Q泵 If so, a leak alarm will be triggered; (2) Guiding accuracy calibration: Drive the slider at a constant low speed V 校准 Perform multiple full-stroke reciprocating motions and record the actual displacement value S of the displacement sensor. 实际 ; Calculate the maximum displacement deviation ΔS for each time. max = |S 理论 - S 实际 |;If ΔS in any one of the multiple movements max ≥ 0.1%·S 总 If this occurs, a guidance accuracy alarm will be triggered, and gap compensation will be performed via the adjustable wedge block. The compensation amount is ΔS. max / 2; where: Q 泵 S represents the rated output flow rate (L / min) of the hydraulic system. 总 This indicates the total stroke length (mm) of the slider design.

[0012] A smart control process for a sludge compression molding hydraulic press as described in any of the above descriptions is characterized by comprising the following steps: A. Parameter Initialization: Input the initial sludge moisture content ω0, density ρ, and single feeding volume V through the mobile control panel. The system will automatically calculate the preset initial pressing force. : Where α is the compaction coefficient, ρ is the sludge density (kg / m³), V is the single-batch feeding volume (m³), ω is the initial moisture content (mass fraction), and A 模具 This represents the mold's projected area, in m², which is automatically identified from the mold's dimensions. B. Dynamic Pressing Control: The PLC collects the real-time pressure p(t) of the main cylinder and the real-time displacement s(t) of the slider in real time, and calculates the pressing force detected in real time. If |F 实时 -F 初始 | ≥10%•F 初始 Then, the pressing speed v(t) is corrected according to the following formula: The compression speed is adjusted, where: v0 is the initial compression speed in mm / s, λ is the dynamic adjustment coefficient, 0.2 ≤ λ ≤ 0.5; F 初始 The initial suppressive force is preset, and v(t) is the dynamically adjusted suppressive speed. C. Adaptive adjustment during the pressure holding phase: h is measured in real time. 实时 Calculate the compression ratio h 初始 / h 实时 Dynamically set the pressure holding time t 保压 =k·(h 初始 / h 实时)·ln(1 +Δp), where: k is the material creep coefficient, 5s≤k≤30s, determined experimentally; Δp = (P 设定 -P 实时 ) / P 设定 When Δp ≥ 5%·P 设定 Time-triggered pressure replenishment, oil replenishment amount Q 补 = Δp·V 腔 / E 油液 , where: V 腔 Hydraulic enclosed volume, unit: L; E 油液 This refers to the elastic modulus of the oil, in Pa. D. Demolding resistance prediction and mold opening control: Predict the demolding force F based on the pressure decay rate ΔP / Δt at the end of the holding pressure. 脱模 =K·(ΔP / Δt), where K is the prediction coefficient, in N·s / Pa, calibrated experimentally according to V. 开模 = V max · exp(-C · F 脱模 / A 模具 Set the mold opening speed, where: V max The maximum allowable mold opening speed of the equipment is expressed in mm / s. C is the process coefficient, where 0.001 m² / N ≤ C ≤ 0.01 m² / N; A 模具 The area is the projected area of ​​the mold, in m². E. Quality Feedback and Process Optimization: Calculating the density ρ of the formed blank. 成型 = m 干料 / [V·(1 -ω0)], where: m 干料 V is the mass of the dried sludge, in kg; V is the volume of the molded blank, in m³; ω0 is the initial moisture content; if |ρ 成型 -ρ 目标 |≥ 2 %·ρ 目标 The system automatically triggers a secondary compression cycle.

[0013] Furthermore, the dynamic suppression control (B) also includes: Pressure fluctuation detection: Real-time monitoring of the master cylinder's real-time pressure p(t). If the relative pressure fluctuation Δp = |P 设定 -P 实时 | / P 设定 If ×100% ≥15%, the hydraulic system self-test procedure will be triggered; among which, The proportion of pressure loss, i.e. , where P 实时 To address the current monitoring pressure, p 设定 The preset pressure holding target pressure; Self-inspection procedure: sequentially check oil cleanliness and pump leakage rate Q.泄露 Pressure sensor accuracy; Fault handling: If the fault persists, the system will automatically switch to the backup hydraulic pump and trigger an audible and visual alarm signal through the human-machine interface.

[0014] Compared with existing technologies, the advantages of this invention are: This invention proposes a sludge compression molding hydraulic press and its intelligent control process. Through innovative structural design (such as a three-beam, four-column body and a stepped, multi-stage ejector lower cylinder) and integration with an intelligent control system, it achieves high-pressure output (≥50MPa), dynamic parameter adjustment, and process optimization. Key technologies such as real-time compression force calculation based on sludge moisture content, closed-loop control using magnetostrictive displacement sensors, and a PLC-integrated self-testing module significantly improve equipment accuracy and reliability. Furthermore, the mobile operating console incorporates a process database and adaptive algorithms to recommend optimal compression parameters, reducing manual trial-and-error costs and providing an efficient and energy-saving solution for sludge resource utilization. Attached Figure Description

[0015] Figure 1 This is a three-dimensional structural diagram of the sludge compression molding hydraulic press in this invention; Figure 2 This is a front view of the sludge compression molding hydraulic press of the present invention; Figure 3 This is a side view of the sludge compression molding hydraulic press in this invention; Figure 4 This is an application diagram of the sludge compression molding hydraulic press in this invention; In the diagram: 1-guide rod; 2-main cylinder; 3-upper crossbeam; 4-slider; 5-support rod; 6-lower crossbeam; 8-displacement sensor; 9-power distribution cabinet; 10-filling tank; 11-oil tank; 12-moving operating platform; 13-multi-stage ejector lower cylinder; 14-mold; 15-sludge feeding device; 17-foundation. Detailed Implementation

[0016] 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.

[0017] Example 1: A sludge compression molding hydraulic press, comprising: The three-beam four-column frame is installed on the foundation 17. The three-beam four-column frame includes an upper crossbeam 3, a lower crossbeam 6, a slider 4 and four guide rods. The four guide rods 1 pass through the upper crossbeam 3 and are slidably connected to the slider 4 located at the lower end of the upper crossbeam 3. The upper crossbeam 3 and the lower crossbeam 6 are connected by a support rod 5. Hydraulic system: includes multiple main cylinders 2 and multi-stage ejector cylinders 13. The main cylinders 2 pass through the upper crossbeam 3 and are connected to the slider 4. The multi-stage ejector cylinders 13 are installed in the foundation 17. The multi-stage ejector cylinders 13 adopt a stepped piston structure and have a maximum output pressure ≥50MPa. A displacement sensor 8 is installed on the guide rod 1 to monitor the stroke displacement of the slider 4 during its up and down movement. Fluid filling and oil tank system: Fluid filling tank 10 is connected to master cylinder 2 through solenoid valve, and oil tank 11 has a built-in magnetic filter and oil temperature control system. The oil cleanliness level NAS is ≤8. Intelligent control system: Integrated into the power distribution cabinet 9, the pressing parameters are set via the mobile control panel 12, and the pressing force F is calculated in real time based on the sludge moisture content ω. Where α is the compaction coefficient, ρ is the sludge density, V is the single feeding volume, and A 模具 The projected area of ​​the mold (14).

[0018] The working principle in this embodiment is as follows: 1. Feeding and pre-compression: The sludge is quantitatively fed into the mold 14 by the sludge feeding device 15. The mold 14 containing the sludge is then transported to the pressing table of the lower crossbeam 6 via the conveying track. The slider 4 moves down to complete the pre-compression. 2. Main pressing stage: Main cylinder 2 applies pressure, and the pressing force is calculated according to the formula. Dynamic adjustment; 3. Pressure holding and demolding: After pressure holding, the mold opening speed is controlled according to the demolding resistance prediction model. The molded sludge is ejected and demolded through the multi-stage ejection cylinder 13, avoiding product damage during the ejection and demolding process. 4. Quality feedback: Real-time detection of molding density; if the target value is not reached, a second pressing cycle is automatically triggered.

[0019] The technical advantages of this embodiment include high-precision control: through displacement sensor 8 and servo hydraulic system, the pressing stroke error is ≤0.1mm; energy saving and high efficiency: oil cleanliness and temperature control extend equipment life; NAS≤8 level filtration reduces system wear; intelligent adaptation: based on dynamic calculation of water content and density, it adapts to the process requirements of different sludge compositions.

[0020] In Example 2, the piston diameter of the multi-stage ejector lower cylinder (13) is designed in a proportional sequence, and the ejection ratio of each stage is set to increase by k, with the final stage ejection force... Where k>1, n is the series, and p1 is the primary top output force.

[0021] In this embodiment, high pressure output is achieved by proportional top output force, avoiding system instability caused by single-stage pressurization, and reducing energy consumption. In this embodiment, each piston stage is equipped with an independent sealing ring and guide sleeve to ensure interstage pressure transmission efficiency ≥95%. The piston material is high-strength alloy steel (such as 42CrMo4), with hard chrome plating on the surface and a hardness ≥HRC 60.

[0022] Example 3, based on Example 1 above, the sealing structure of the main cylinder 2 includes a piston rod seal and a cylinder port, with a double dustproof ring provided at the cylinder port. In this example, the piston rod seal uses an imported polyurethane U-ring 14, with a pressure resistance ≥60MPa and an operating temperature range of -30℃ to +120℃; the dynamic friction coefficient of the sealing ring is ≤0.15, and its lifespan is ≥10 years. 6 The reciprocating motion and cylinder port dustproof design include: double dustproof rings 15 arranged at the cylinder port, made of fluororubber (FKM); dustproof rating: conforms to international protection rating IP67 (complete dustproof, short-term waterproof immersion); additional function: built-in scraper blades to remove impurities from the piston rod surface, reducing seal wear; double dustproof rings 16 at the cylinder port, made of fluororubber, with a dustproof rating of IP67 (complete dustproof, short-term waterproof immersion); additional function: built-in scraper blades to remove impurities from the piston rod surface, reducing seal wear; sealing performance verification: passed ISO 10766 standard test, leakage ≤0.1mL / min (under rated pressure); anti-contamination capability: when NAS 1638 oil cleanliness level ≤8, the seal has no failure. In this embodiment, the polyurethane U-ring and double dustproof design ensure the reliability of the main cylinder under extreme pressure (≥60MPa) and complex working conditions. The sealing structure has excellent wear resistance, which can reduce the frequency of downtime maintenance. The IP67 dustproof rating is suitable for humid and dusty industrial environments, extending the service life of the equipment.

[0023] Example 4: Based on the above examples, the PLC dynamically adjusts the pressing speed of the master cylinder (2) based on the proportional-integral-derivative (PID) control algorithm, specifically as follows: (1) Calculate the current displacement deviation: e=S 设定 -S 当前 In this embodiment, within a sampling period of T=10ms, the PLC reads the current position S of the slider through the displacement sensor (8). 当前， And the target displacement S of this suppression segment 设定 By subtraction, we obtain the displacement deviation: e = S 设定 -S 当前 (2) Based on the displacement deviation e, calculate the speed adjustment Δv using the PID control algorithm: Δv = Kp·e + Ki·∫e dt + Kd·(de / dt), where Kp is the proportionality coefficient, Ki is the integral coefficient, and Kd is the differential coefficient. In this embodiment, Kp is set to 2.5 mm·s⁻¹·mm⁻¹; Ki = 0.08 mm·s⁻¹·mm⁻¹·s⁻¹; Kd = 18 mm·s⁻¹·mm⁻¹·s. The integral term ∫e dt uses trapezoidal summation, and the differential term (de / dt) uses first-order backward difference: de / dt≈(e n -e n ₋1) / T (3) Adjust the current suppression speed to: v 新 =v 当前 +Δv, where the output Δv of the PID control algorithm is proportional to the displacement deviation e, the cumulative amount of the deviation, and the rate of change of the deviation. In this embodiment, the current cycle suppression speed v is... 当前 Adding this to Δv yields the new velocity command: v 新 =v 当前 +Δv,v 新 After D / A conversion, the output is sent to the proportional flow valve to drive the master cylinder to complete closed-loop speed regulation.

[0024] Example 5, based on Example 1 above, provides a sludge pressing and molding hydraulic press, wherein the steps of the sludge pressing and molding process include: S1. Sludge conveying: After the sludge feeding device 15 feeds the sludge into the mold 14, the mold 14 containing the sludge is conveyed to the pressing table of the liquid forming hydraulic press via the track. S2, Rapid Descending: Slider 4 descends to the surface of mold 14; S3, Pressing: Slider 4 presses the set pressure value. Alternatively, the set termination stroke S can be used for suppression; S4, Pressure Holding: Pressure holding time Where γ is the sludge coefficient, calibrated experimentally, with a value ranging from 0.3 to 2.0 mm⁻¹; h 污泥 This represents the initial thickness of the sludge inside the mold, in mm. This represents the proportional relationship between sludge compression or pressure change, where ω is the moisture content correction factor, and 1 < ω ≤ 2; S5. Pressure relief: Two-stage pressure relief, first to ≤5 MPa, then to ≤0.5 MPa; S6, Return: The slider returns to its initial position; S7. Ejection and Demolding: The multi-stage ejection cylinder 13 ejects the pressed sludge and demolds it.

[0025] In this embodiment, please refer to the accompanying drawings. Figure 4 The above-mentioned S7 also includes: a conveying track to transport the sludge pressed in the mold 14 to the position of the multi-stage ejection lower cylinder 13. In this embodiment, the structure of the mold 14 includes an upper mold, a lower mold and a mold base plate. The upper mold and the lower mold are connected by a telescopic rod. The diameter of the upper mold is smaller than the diameter of the lower mold. In this embodiment, the lower mold can be raised and sleeved below the upper mold by an electrically controlled telescopic rod. After the sludge in the mold is pressed into shape, the entire mold containing the sludge is transported to the multi-stage ejection lower cylinder 13 by the conveying track, so that the center hole of the mold base plate corresponds to the multi-stage ejection lower cylinder 13. There is a movable cover plate with a sensor at the center hole. After the sensor senses that the position of the center hole corresponds to and fits with the lower multi-stage ejection lower cylinder 13, the movable cover plate is opened and the multi-stage ejection lower cylinder 13 extends upward to eject the formed sludge and remove it from the mold base plate.

[0026] Example 6: Based on the above examples, a sludge compression molding hydraulic press, wherein step S4, pressure holding, further includes pressure replenishment. Pressure replenishment is triggered when the pressure loss ratio ΔP ≥ 5%. The conditions for triggering pressure replenishment are as follows: The number of repressurization cycles is ≤3, and the time for each repressurization cycle is ≤2 seconds. The pressure loss ratio represents the initial pressure P during the pressure holding phase. 初始 Real-time pressure P monitored during the pressing process 实时 The relative difference.

[0027] Example 7: Based on Example 1 above, the mobile operating console 12 includes a storage unit and a processor. The storage unit has a built-in process database and supports the calculation of the optimal pressing speed v using the following formula. 最优 : Where k is a dimensionless comprehensive empirical coefficient, 100 ≤ k ≤ 850, determined by fitting historical process data; E 污泥 The elastic modulus of sludge is expressed in Pa; h. 污泥 F represents the initial thickness of the sludge inside the mold, in mm. 模 The unit for estimating the release force is N.

[0028] In this embodiment, the specific workflow is as follows: 1. After feeding, the PLC reads h 污泥 E 污泥 and F 模 Real-time value; 2. Select the corresponding k value based on the current ω interval: When ω ≤ 45%, k = 820; When 45% < ω ≤ 55%, k = 650; When 55% < ω ≤ 65%, k = 480; When ω > 65%, k = 320; 3. (The rest of the text appears to be a list of characters and symbols, possibly related to a command or instruction.) 污泥 E 污泥 F 模 Substituting into the above formula, we can calculate v. 最优 The unit is mm / s; 4. v 最优 After D / A conversion, the output is sent to the main cylinder proportional flow valve as the setpoint for the PID speed loop to achieve closed-loop suppression.

[0029] Example 8: Based on Example 1 above, the PLC control program integrates a self-test module. This module performs the following self-tests using a pressure sensor, a displacement sensor, and a proportional valve: (1) Hydraulic system leakage detection: shut down all actuators, start the hydraulic pump and maintain the test pressure P 测试 Measure the pressure drop per unit time ΔP / Δt, Q 泄露 = (ΔP / Δt) · V 系统 / E 油液 Calculate the leakage flow rate, V 系统 For a hydraulically enclosed volume, the system's elastic modulus E is used. 油液 Converted to leaked traffic, if Q 泄露 ≥ 0.1%·Q 泵 If the leakage alarm is triggered, then in this embodiment, all actuators, including the master cylinder, lower cylinder, and directional valve, are shut down, and the hydraulic pump is started to pressurize the system to the test pressure P. 测试 =25MPa, and immediately shut off the pump outlet proportional valve to form a closed volume; record the pressure P0 at t=0 s, and continuously monitor for 60 s to obtain the pressure drop value ΔP = P0 – P60; calculate the pressure drop rate per unit time ΔP / Δt = (P0– P60) / 60 s; convert the leakage flow rate Q according to the following formula. 泄露 Q 泄露 = (ΔP / Δt) · V 系统 / E 油液 In the formula, V 系统 The hydraulically enclosed volume includes the rodless chamber volume of the master cylinder, the pipeline volume, and the internal passage volume of the valve block. In this embodiment, V 系统 =4.2 L; E 油液 The effective bulk modulus of the oil is 1.6 × 10³ MPa (measured). Q 泄露Unit: L / min, conversion factor: 60000 (mm³·min⁻¹·s); if Q 泄露 ≥ 0.1% ·Q 泵 (Q) 泵 = 75 L / min), that is, 75 mL / min, the system immediately triggers a leakage alarm and displays "hydraulic system leakage exceeds the standard" on the human-machine interface, while locking the master cylinder start signal and waiting for manual investigation.

[0030] (2) Guiding accuracy calibration: Drive slider 4 at a constant low speed V 校准 Perform multiple full-stroke reciprocating motions and record the actual displacement value S of displacement sensor 8. 实际 ; Calculate the maximum displacement deviation ΔS for each time. max = |S 理论 - S 实际 |;If ΔS in any one of the multiple movements max ≥ 0.1%·S 总 If this occurs, a guidance accuracy alarm will be triggered, and gap compensation will be performed via the adjustable wedge block. The compensation amount is ΔS. max / 2; where: Q 泵 S represents the rated output flow rate (L / min) of the hydraulic system. 总 This indicates the total stroke length (mm) of the slider 4 design; specifically, in this embodiment, the slider 4 is driven at a constant low speed V. 校准 = 5 mm / s for 3 full-stroke reciprocating motions; total stroke length S 总 = 800 mm; During each movement, displacement sensor 8 outputs the actual displacement S in real time with a sampling period of 1 ms; PLC synchronously records the theoretical displacement S at the corresponding moment. 理论 (Generated from a uniform speed command); Calculate the maximum displacement deviation ΔS for each round trip. max = |S 理论 - S 实际 |max, in this embodiment, is set 3 times ΔS max The values ​​are 0.35 mm, 0.42 mm, and 0.38 mm, respectively; Judgment: If any ΔS max ≥ 0.1% · S 总 If the deviation is less than 0.8 mm, a guide accuracy alarm will be triggered; in this example, 0.42 mm < 0.8 mm, so no alarm is triggered; when an alarm is triggered, the PLC drives the adjustable wedge to press the guide rail, with a compensation amount of ΔS. max / 2, compensate resolution 0.01 mm, run calibration again after compensation, until ΔS max Automatic pressing mode can be entered only when the diameter is < 0.8 mm.

[0031] This embodiment uses a PLC self-test module to achieve automatic monitoring and closed-loop control of hydraulic system leakage, guiding accuracy, and slider displacement, which significantly improves equipment reliability and reduces scrap rate caused by mechanical deviation or leakage. It is suitable for high-precision sludge pressing and molding processes.

[0032] Example 9, Intelligent control process of sludge compression molding hydraulic press, characterized by including the following steps: A. Parameter Initialization: Input the initial sludge moisture content ω0, density ρ, and single feeding volume V through the mobile control panel 12. The system will automatically calculate the preset initial pressing force. : Where α is the compaction coefficient, ρ is the sludge density (kg / m³), V is the single-batch feeding volume (m³), ω is the initial moisture content (mass fraction), and A 模具 The projected area of ​​mold 14 is in m², which is automatically identified from the dimensions of mold 14. B. Dynamic pressing control: The PLC collects the real-time pressure p(t) of the main cylinder 2 and the real-time displacement s(t) of the slider in real time, and calculates the pressing force detected in real time. If |F 实时 -F 初始 | ≥10%•F 初始 Then, the pressing speed v(t) is corrected according to the following formula: The compression speed is adjusted, where: v0 is the initial compression speed in mm / s, λ is the dynamic adjustment coefficient, 0.2 ≤ λ ≤ 0.5; F 初始 The initial suppressive force is preset, and v(t) is the dynamically adjusted suppressive speed. C. Adaptive adjustment during the pressure holding phase: h is measured in real time. 实时 Calculate the compression ratio h 初始 / h 实时 Dynamically set the pressure holding time t 保压 =k·(h 初始 / h 实时 )·ln(1 +Δp), where: k is the material creep coefficient, 5s≤k≤30s, determined experimentally; Δp = (P 设定 -P 实时 ) / P 设定 When Δp ≥ 5%·P 设定 Time-triggered pressure replenishment, oil replenishment amount Q 补 = Δp·V 腔 / E 油液 , where: V 腔 Hydraulic enclosed volume, unit: L; E 油液 This refers to the elastic modulus of the oil, in Pa. D. Demolding resistance prediction and mold opening control: Predict the demolding force F based on the pressure decay rate ΔP / Δt at the end of the holding pressure. 脱模 =K·(ΔP / Δt), where K is the prediction coefficient, in N·s / Pa, calibrated experimentally according to V. 开模 = V max · exp(-C · F 脱模 / A 模具 Set the mold opening speed, where: V max The maximum allowable mold opening speed of the equipment is expressed in mm / s. C is the process coefficient, where 0.001 m² / N ≤ C ≤ 0.01 m² / N; A 模具 The area is the projected area of ​​the mold, in m². E. Quality Feedback and Process Optimization: Calculating the density ρ of the formed blank. 成型 = m 干料 / [V·(1 -ω0)], where: m 干料 V is the mass of the dried sludge, in kg; V is the volume of the molded blank, in m³; ω0 is the initial moisture content; if |ρ 成型 -ρ 目标 |≥ 2 %·ρ 目标 The system automatically triggers a secondary compression cycle.

[0033] In this embodiment, the intelligent control process of the sludge pressing and molding hydraulic press described in this patent will be described in detail below with reference to the above embodiments. This embodiment achieves high-precision sludge molding by integrating dynamic pressing force calculation, real-time feedback adjustment, adaptive pressure holding and pressure compensation logic. The specific implementation steps are as follows: A. Parameter initialization: The system automatically calculates the initial compaction force by inputting the sludge density ρ (kg / m³), single feeding volume V (m³), and initial moisture content ω0 through a mobile control panel. .

[0034] In this embodiment, α = 0.65 is set as the compaction coefficient, A 模具 = 0.64 m² Automatically identified by mold dimensions, ω0 = 0.52. α = 0.65, ρ = 1180 kg / m³ (density of typical municipal dewatered sludge). V = 0.25 m³ (single mold feeding volume). ω0 = 0.52 (52% moisture content, mass fraction). A 模具 = 0.64 m², F 初始= 0.65 × 1 / (180 × 0.25 × (1 − 0.52) / 0.64) = 0.65 × 1 / (180 × 0.25 × 0.48 / 0.64) ≈ 143 kN, Therefore, the initial compressive force given by the system is approximately 1.43 × 10⁻⁶. 5 N (143 kN).

[0035] B. Dynamic suppression control: The PLC is configured to acquire the main cylinder pressure p(t) and slider displacement s(t) at 10 ms intervals to obtain the real-time pressing force. F 实时 = p(t) · A 活塞 , When |F 实时 - F 初始 | ≥ 10% F initially, the velocity is corrected according to the exponential formula: v(t) = v0 · (F 实时 / F 初始 ) λ , v0 = 80 mm / s, λ = 0.35, limit amplitude 5–120 mm / s, in this embodiment, F 初始 =143 kN, When the real-time pressure p(t) rises to 1.26 MPa: F 实时 = 1.26 MPa × 0.125 m² = 157.5 kN, Deviation ΔF = 157.5 − 143 = 14.5 kN > 14.3 kN → Trigger correction.

[0036] Speed ​​correction: v(t) = 80 mm / s × (157.5 / 143)^0.35 = 80 × (1.101)^0.35 ≈ 80 × 1.034 ≈ 82.7 mm / s, Result: The pressing speed was dynamically increased from 80 mm / s to approximately 83 mm / s, still within the 5–120 mm / s limit.

[0037] Example 10, based on the above examples, the dynamic suppression control (B) further includes: Pressure fluctuation detection: Real-time monitoring of the real-time pressure p(t) of master cylinder 2; if the relative pressure fluctuation Δp = |P 设定 -P 实时 | / P 设定 If ×100% ≥15%, the hydraulic system self-test procedure will be triggered; among which, The proportion of pressure loss, i.e. , where P 实时 To address the current monitoring pressure, p 设定 The preset pressure holding target pressure; Self-inspection procedure: sequentially check oil cleanliness and pump leakage rate Q. 泄露 Pressure sensor accuracy; Fault handling: If the fault persists, the system will automatically switch to the backup hydraulic pump and trigger an audible and visual alarm signal through the human-machine interface.

[0038] In this embodiment, based on the above embodiment, the PLC runs the "pressure fluctuation self-test submodule" in real time during the pressing stage. The specific process is as follows: Fluctuation detection: Preset pressure holding target pressure P 设定 = 25.0 MPa.

[0039] The PLC reads the master cylinder pressure sensor at 10 ms intervals to obtain P. 实时 .

[0040] Calculate relative fluctuations: Δp = |P 设定 - P 实时 | / P 设定 × 100%, When Δp ≥ 15% (i.e., |25.0 − P) 实时 | ≥ 3.75 MPa) immediately triggers the hydraulic system self-check flag. The self-check procedure executes (lasts ≤ 8 s).

[0041] a) Oil cleanliness The ISO 4406 grade was obtained by sampling 100 mL using an online particle counter. If the cleanliness level is ≥ 19 / 16 / 13, it is determined that the cleanliness exceeds the standard.

[0042] b) Pump unit leakage rate Q 泄露 Shut down all actuators and boost voltage to P. 测试 = After 25 MPa, it is locked, and the pressure drops by ΔP = 1.2 MPa within 60 s; Q泄露 = (ΔP / Δt) · V 系统 / E 油液 , This machine's V 系统 = 4.2 L, E 油液 = 1.6 × 10³ MPa, Q 泄露 = (1.2 MPa / 60 s) × 4.2 L / 1600 MPa ≈ 0.053 L / min, 0.1 %Q 泵 = 0.075 L / min (Q 泵 = 75 L / min), 0.053 < 0.075, the leakage is qualified.

[0043] c) Pressure sensor accuracy Relieve the pressure to 0 MPa, read the zero-point output, and the zero-point drift ≤ ±0.02 MPa is qualified; If it is out of tolerance, mark "Sensor accuracy failure".

[0044] Fault handling: If any item is unqualified and not restored within 8 s: → The PLC immediately cuts off the main pump and starts the standby pump (switching time 1.5 s); → A red dialog box "Hydraulic system abnormal" pops up on the human-machine interface, and at the same time, the audible and visual alarm is driven (frequency 1 Hz, sound level 85 dB); → The current green body continues to complete the pressing and then locks the automatic cycle, waiting for manual confirmation.

[0045] If it runs continuously for 30 days, a total of 12 fluctuation self-checks are triggered. Among them, the standby pump is switched 2 times due to excessive particle count. The scrap rate is reduced from 1.9 % to 0.3 %, and the downtime is reduced by 6 h / month, which proves that this pressure fluctuation detection and self-check strategy can significantly improve the equipment reliability and forming qualification rate.

[0046] The above is only the preferred specific implementation manner 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 replacements or changes, and all should be covered within the protection scope of the present invention.

Claims

1. A sludge compression molding hydraulic press, characterized in that, include: The three-beam four-column fuselage is installed on the foundation (17). The three-beam four-column fuselage includes an upper crossbeam (3), a lower crossbeam (6), a slider (4), and four guide rods (1). The four guide rods (1) pass through the upper crossbeam (3) and are slidably connected to the slider (4) located at the lower end of the upper crossbeam (3). The upper crossbeam (3) and the lower crossbeam (6) are connected by a support rod (5). Hydraulic system: includes multiple main cylinders (2) and multi-stage ejector cylinders (13). The main cylinders (2) pass through the upper crossbeam (3) and are connected to the slider (4). The multi-stage ejector cylinders (13) are set in the foundation (17) and adopt a stepped piston structure. A displacement sensor (8) is set on the guide rod (1) to monitor the stroke displacement of the slider (4) moving up and down. Filling and oil tank system: The filling tank (10) is connected to the main cylinder (2) through a solenoid valve, and the oil tank (11) has a built-in magnetic filter and oil temperature control system; Intelligent control system: integrated into the power distribution cabinet (9), the pressing parameters are set through the mobile operating console (12), and the pressing force F is calculated in real time based on the sludge moisture content ω0. Where α is the compaction coefficient, ρ is the sludge density, V is the single feeding volume, and A 模具 The projected area of ​​the mold (14).

2. The sludge pressing and molding hydraulic press according to claim 1, characterized in that, The piston diameter of the multi-stage ejector lower cylinder (13) is designed in a proportional sequence, with the ejection ratio increasing by k for each stage, and the ejection force of the final stage... Where k>1, n is the series, and p1 is the primary top output force.

3. The sludge pressing and molding hydraulic press according to claim 1, characterized in that, The sealing structure of the main cylinder (2) includes a piston rod seal and a cylinder port, with a double dustproof ring provided at the cylinder port. The displacement sensor (8) detects the displacement feedback data of the slider (4) and sends it to the PLC. The PLC dynamically adjusts the pressing speed of the main cylinder (2) based on the proportional-integral-derivative (PID) control algorithm, specifically: (1) Calculate the current displacement deviation: e=S 设定 -S 当前 ; (2) Based on the displacement deviation e, calculate the speed adjustment Δv using the PID control algorithm: Δv = Kp·e + Ki·∫e dt + Kd·(de / dt), where Kp is the proportionality coefficient, Ki is the integral coefficient, and Kd is the differential coefficient. (3) Adjust the current suppression speed to: v 新 =v 当前 +Δv, where the output Δv of the PID control algorithm is proportional to the displacement deviation e, the cumulative amount of the deviation, and the rate of change of the deviation.

4. A hydraulic press for sludge pressing and molding process, comprising the sludge pressing and molding hydraulic press according to any one of claims 1-3, characterized in that, The steps of the sludge compression molding process include: S1. Sludge conveying: After the sludge feeding device (15) feeds the sludge into the mold (14), the mold (14) containing the sludge is conveyed to the pressing table of the liquid forming hydraulic press through the track. S2, Rapid descent: The slider (4) descends to the surface of the mold (14); S3, Pressing: Slider (4) presses the set pressure value. Alternatively, the set termination stroke S can be used for suppression; S4, Pressure Holding: Pressure holding time Where γ is the sludge coefficient, calibrated experimentally, with a value ranging from 0.3 to 2.0 mm⁻¹; h 污泥 This represents the initial thickness of the sludge inside the mold, in mm. This represents the proportional relationship between sludge compression or pressure change, where ω is the moisture content correction factor, and 1 < ω ≤ 2; S5. Pressure relief: Two-stage pressure relief, first to ≤5 MPa, then to ≤0.5 MPa; S6, Return: The slider returns to its initial position; S7. Ejection and demolding: The multi-stage ejection cylinder (13) ejects the pressed sludge and demolds it.

5. A sludge pressing and molding hydraulic press according to claim 4, characterized in that, The S4 pressure holding step also includes pressure replenishment. Pressure replenishment is triggered when the pressure loss ratio ΔP ≥ 5%. The conditions for triggering pressure replenishment are as follows: The number of repressurization cycles is ≤3, and the time for each repressurization cycle is ≤2 seconds. The pressure loss ratio represents the initial pressure P during the pressure holding phase. 初始 Real-time pressure P monitored during the pressing process 实时 The relative difference.

6. A sludge compression molding hydraulic press according to claim 1, characterized in that, The mobile control panel (12) includes a storage unit and a processor. The storage unit has a built-in process database and supports the calculation of the optimal pressing speed v using the following formula. 最优 : Where k is a dimensionless comprehensive empirical coefficient, 100 ≤ k ≤ 850, determined by fitting historical process data; E 污泥 The elastic modulus of sludge is expressed in Pa; h. 污泥 F represents the initial thickness of the sludge inside the mold, in mm. 模 The unit for estimating the release force is N.

7. A sludge pressing and molding hydraulic press according to claim 3, characterized in that, The PLC control program integrates a self-test module, which performs the following self-tests using pressure sensors, displacement sensors, and proportional valves: (1) Hydraulic system leakage detection: shut down all actuators, start the hydraulic pump and maintain the test pressure P 测试 Measure the pressure drop per unit time ΔP / Δt, according to Q. 泄露 = (ΔP / Δt) · V 系统 / E 油液 Calculate the leakage flow rate, V 系统 For a hydraulically enclosed volume, the system's elastic modulus E is used. 油液 Converted to leaked traffic, if Q 泄露 ≥ 0.1%·Q 泵 If so, a leak alarm will be triggered; (2) Guiding accuracy calibration: Drive the slider (4) at a constant low speed V 校准 Perform multiple full-stroke reciprocating motions and record the actual displacement value S of the displacement sensor (8). 实际 ; Calculate the maximum displacement deviation ΔS for each time. max = |S 理论 - S 实际 |;If ΔS in any one of the multiple movements max ≥ 0.1%·S 总 If this occurs, a guidance accuracy alarm will be triggered, and gap compensation will be performed via the adjustable wedge block. The compensation amount is ΔS. max / 2; where: Q 泵 S represents the rated output flow rate (L / min) of the hydraulic system. 总 The total stroke length (mm) of the slider (4) design is indicated.

8. An intelligent control process for a sludge compression molding hydraulic press as described in any one of claims 1-3, characterized in that, Includes the following steps: A. Parameter initialization: Input the initial moisture content ω0, density ρ, and single feeding volume V of the sludge through the mobile operating console (12), and the system will automatically calculate the preset initial pressing force. : Where α is the compaction coefficient, ρ is the sludge density (kg / m³), V is the single-batch feeding volume (m³), ω is the initial moisture content (mass fraction), and A 模具 The projected area of ​​the mold (14) is in m², which is automatically identified by the size of the mold (14). B. Dynamic pressing control: The PLC collects the real-time pressure p(t) of the main cylinder (2) and the real-time displacement s(t) of the slider in real time, and calculates the pressing force detected in real time. If |F 实时 -F 初始 | ≥10%•F 初始 Then, the pressing speed v(t) is corrected according to the following formula: The compression speed is adjusted, where: v0 is the initial compression speed in mm / s, λ is the dynamic adjustment coefficient, 0.2 ≤ λ ≤ 0.5; F 初始 The initial suppressive force is preset, and v(t) is the dynamically adjusted suppressive speed. C. Adaptive adjustment during the pressure holding phase: h is measured in real time. 实时 Calculate the compression ratio h 初始 / h 实时 Dynamically set the pressure holding time t 保压 =k·(h 初始 / h 实时 )·ln(1 +Δp), where: k is the material creep coefficient, 5s≤k≤30s, calibrated by experiment; Δp =(P 设定 -P 实时 ) / P 设定 When Δp ≥ 5%·P 设定 Time-triggered pressure replenishment, oil replenishment amount Q 补 = Δp·V 腔 / E 油液 , where: V 腔 Hydraulic enclosed volume, unit: L; E 油液 This refers to the elastic modulus of the oil, in Pa. D. Demolding resistance prediction and mold opening control: Predict the demolding force F based on the pressure decay rate ΔP / Δt at the end of the holding pressure. 脱模 =K·(ΔP / Δt), where K is the prediction coefficient, in N·s / Pa, calibrated experimentally according to V. 开模 = V max · exp(-C· F 脱模 / A 模具 Set the mold opening speed, where: V max The maximum allowable mold opening speed of the equipment is expressed in mm / s. C is the process coefficient, where 0.001 m² / N ≤ C ≤ 0.01 m² / N; A 模具 The area is the projected area of ​​the mold, in m². E. Quality Feedback and Process Optimization: Calculating the density ρ of the formed blank. 成型 = m 干料 / [V·(1 -ω0)], where: m 干料 V is the mass of the dried sludge, in kg; V is the volume of the molded blank, in m³; ω0 is the initial moisture content; if |ρ 成型 -ρ 目标 |≥ 2%·ρ 目标 The system automatically triggers a secondary compression cycle.

9. The intelligent control process for a sludge compression molding hydraulic press according to claim 7, characterized in that, The dynamic suppression control (B) also includes: Pressure fluctuation detection: Real-time monitoring of the real-time pressure p(t) of the master cylinder (2). If the relative pressure fluctuation Δp = |P 设定 - P 实时 | / P 设定 If ×100% ≥15%, the hydraulic system self-test procedure will be triggered; among which, The proportion of pressure loss, i.e. , where P 实时 To address the current monitoring pressure, p 设定 The preset pressure holding target pressure; Self-inspection procedure: sequentially check oil cleanliness and pump leakage rate Q. 泄露 Pressure sensor accuracy; Fault handling: If the fault persists, the system will automatically switch to the backup hydraulic pump and trigger an audible and visual alarm signal through the human-machine interface.

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