Reconstruction of proportional control unit of hydraulic system of quick forging machine and fault diagnosis system and method

Abstract

This invention discloses a system and method for reconstructing and diagnosing the proportional control unit of a high-speed forging machine's hydraulic system. The system includes a proportional control unit reconstructing the hydraulic control valve group, a multi-source status sensing module, a PLC control unit, a host computer visualization platform, and a fault diagnosis and rapid processing module. The proportional control unit reconstructs the hydraulic control valve group, replacing the valve group in the original hydraulic system of the 45MN high-speed forging machine. The multi-source status sensing module collects hydraulic system operating parameters. The PLC control unit receives the signals collected by the multi-source status sensing module and interacts with the host computer. The host computer visualization platform visualizes the hydraulic system's operating status. The fault diagnosis and rapid processing module runs on the host computer, identifies hydraulic system faults, and outputs diagnostic conclusions and processing steps. This system can automatically identify faults in the high-speed forging machine's hydraulic system, reducing fault location time from hours to less than 5 minutes, reducing downtime by more than 30%, and lowering maintenance costs by more than 40%.

Description

Technical Field

[0001] This invention belongs to the field of hydraulic control technology for heavy forging equipment, and relates to a system and method for reconstructing and diagnosing the proportional control unit of the hydraulic system of a high-speed forging machine. Background Technology

[0002] High-speed forging hydraulic presses, also known as "fast forging presses," are suitable for rapid forging processes of metal materials. They generally employ a modular design, with the main unit using various structures such as an integral frame double-column pull-down type, a prestressed double-column pull-down type, a double-column inclined prestressed body, or an upper-pressing type. The frame columns feature a trapezoidal cross-section design to improve rigidity, strength, and resistance to deformation. High-speed forging hydraulic presses are available in various models, with pressure ranges from 3.15MN to 125MN. Product series include high-speed forging hydraulic press units of various specifications such as 6.3MN, 8MN, 10MN, 12.5MN, 16MN, 20MN, 25MN, 31.5MN, 35MN, 40MN, 45MN, 50MN, 63MN, and 125MN. The 45MN high-speed forging hydraulic press is a core heavy-duty piece of equipment in the high-end equipment manufacturing field, widely used in the precision forming of large forgings in aerospace, nuclear power, and wind power industries. Its hydraulic system features high working pressure (rated working pressure 31.5MPa), large flow (main system flow can reach 8000L / min), high operating frequency (fast forging frequency can reach 90 times / minute), and high control accuracy (position control accuracy ±0.5mm).

[0003] The existing hydraulic systems of 45MN high-speed forging mills generally use analog control split-type servo valves, proportional valves, cartridge valves, and logic valve groups to form proportional control units, which have the following technical defects: (1) The core control valves rely on imports, resulting in high procurement costs and long delivery cycles. The existing system uses split-type analog control valves (such as Rexroth 4WRPEH series high-frequency response proportional servo valves and 4WRPH series pilot-operated proportional servo valves), with a single set procurement cost of approximately RMB 150,000 to 200,000 and a delivery cycle of 6 to 12 months. The spare parts guarantee capability is poor, and valve failure will seriously affect the continuous operation of the equipment. (2) The operating status of the hydraulic system is not visible. The existing system lacks real-time monitoring means for key parameters such as control oil pressure, main valve command signal, pilot valve feedback signal, coil voltage, and valve core opening degree. Operators cannot intuitively grasp the working status of the valve group, and equipment management is in a "black box" state. (3) Troubleshooting relies on manual experience. When problems such as abnormal pressure, valve sticking, internal leakage, and coil failure occur in the system, technicians need to check each item based on their experience. The fault location time usually takes 2-4 hours, resulting in huge downtime losses and a lack of standardized diagnosis and handling procedures. (4) Analog control split valves have closed control interfaces, making it difficult to connect to digital platforms. Existing valves use ±10V analog control signals and have no digital communication interface, making it impossible to achieve remote monitoring, data storage, trend analysis, and predictive maintenance.

[0004] To address the aforementioned issues, some scholars have proposed several improvement solutions. For instance, Chinese Patent CN113898623B discloses a hydraulic system control system and method for a multi-functional forging hydraulic press. This system utilizes a combination of a fixed-displacement pump, a variable-displacement pump, and a proportional servo valve to control three processes: free forging, precision extrusion, and isothermal forging. However, it only addresses the oil supply control and speed regulation of the hydraulic system, without involving the digital reconstruction and replacement of the core proportional control valve. Similarly, Chinese Patent CN119407088B discloses a multi-path control system for a hydraulic high-speed forging machine. This system achieves redundancy and backup of the control system through multiple parallel power supply and cooling devices, improving system reliability. However, it only solves the problems of control oil supply and cooling, without addressing the status monitoring, visualization, and fault diagnosis of the proportional control valve.

[0005] In summary, existing technologies only achieve single valve replacement or simple data monitoring, and have not formed an integrated solution for proportional control unit reconfiguration and replacement, status visualization, fault diagnosis, and rapid processing. Therefore, they cannot meet the needs of independent control and intelligent upgrading of the core control valve of heavy-duty high-speed forging machines. Summary of the Invention

[0006] One objective of this invention is to provide a reconfiguration and fault diagnosis system for the proportional control unit of a high-speed forging machine hydraulic system, which enables the 45MN high-speed forging machine hydraulic system to achieve autonomous control of the core control valve, full visibility of the operating status, rapid fault location, and automated handling process, thereby improving equipment reliability and reducing operation and maintenance costs.

[0007] Another objective of this invention is to provide a method for reconfiguring and diagnosing faults in the proportional control unit of a hydraulic system for a high-speed forging mill.

[0008] The first technical solution adopted in this invention is a proportional control unit reconfiguration and fault diagnosis system for a high-speed forging machine hydraulic system. This system includes a proportional control unit reconfiguration hydraulic control valve group, a multi-source status sensing module, a PLC control unit, a host computer visualization platform, and a fault diagnosis and rapid processing module. The core of the proportional control unit reconfiguration hydraulic control valve group is a digitally controlled integrated high-frequency response proportional servo valve, used to replace the proportional control valve of the main hydraulic cylinder in the original hydraulic system of the 45MN high-speed forging machine. The multi-source status sensing module is used to collect hydraulic system operating parameters in real time. The PLC control unit is used to receive signals collected by the multi-source status sensing module, complete data processing, and interact with the host computer. The host computer visualization platform is used to dynamically visualize the hydraulic system's operating status. The fault diagnosis and rapid processing module runs on the host computer and is used to identify hydraulic system faults and output diagnostic conclusions and processing steps.

[0009] The proportional control unit reconfigures the hydraulic control valve group, which includes a digitally controlled integrated high-frequency response proportional servo valve, a high-flow logic cartridge valve, a pilot-operated proportional relief valve, and a safety valve. It is completely equivalent to the original valve group in the hydraulic system of the 45MN high-speed forging machine in terms of installation interface, control signal, and pressure and flow parameters.

[0010] The digitally controlled integrated high-frequency response proportional servo valve has a rated working pressure of 35MPa, a rated flow rate of 400L / min, a response time ≤10ms, and a control accuracy of ±0.1%. It adopts a CANopen bus digital communication interface, and the control signal is a ±10V analog signal or a CANopen digital signal. The installation interface conforms to the ISO 4401-08 standard. The large-flow logic cartridge valve has a nominal diameter of NG63, a rated working pressure of 31.5MPa, a rated flow rate of 2000L / min, and a proportional pilot control method. The installation interface conforms to the ISO 7368 standard and is used to replace the cartridge valve in the original hydraulic system. The pilot-operated proportional relief valve has a rated working pressure of 31.5MPa and a pressure adjustment range of 0.5MPa~31.5MPa. It adopts a CANopen bus digital communication interface and the installation interface conforms to the ISO 6264 standard. It is used to replace the proportional relief valve in the original hydraulic system.

[0011] The multi-source state sensing module includes a pressure sensor, a differential pressure sensor, a voltage acquisition module, a current acquisition module, a displacement sensor, a temperature sensor, and a timing module. The pressure sensor has a range of 0–40 MPa, an accuracy of ±0.25%FS, and an output signal of 4mA–20mA. It is installed at ports P, A, B, and T of the digitally controlled integrated high-frequency response proportional servo valve. The differential pressure sensor has a range of 0–5 MPa, an accuracy of ±0.5%FS, and an output signal of 4mA–20mA. It is installed between ports P and A, and between ports P and B of the digitally controlled integrated high-frequency response proportional servo valve. The voltage acquisition module has a sampling period of ≤10ms and is used to acquire the main valve command voltage signal, the main valve feedback voltage signal, and the pilot valve command voltage signal of the digitally controlled integrated high-frequency response proportional servo valve. The voltage signal and the pilot valve feedback voltage signal are fed together. The sampling period of the current acquisition module is ≤10ms. It is used to acquire the coil drive current signal of the digitally controlled integrated high-frequency response proportional servo valve. The displacement sensor is a magnetostrictive displacement sensor with a range of 0~100mm, an accuracy of ±0.01mm, and an output signal of 4mA~20mA. It is installed on the valve core position detection end of the digitally controlled integrated high-frequency response proportional servo valve to monitor the opening degree of the main valve core in real time. The temperature sensor has a range of -25℃~100℃, an accuracy of ±0.5℃, and an output signal of 4mA~20mA. It is installed on the valve body surface of the digitally controlled integrated high-frequency response proportional servo valve to monitor the working temperature of the valve group in real time. The timing module is integrated into the PLC control unit to count the cumulative working time of the valve group.

[0012] The CPU processor in the PLC control unit is a CPU 1214C DC / DC / DC, integrating a Profinet communication interface. After receiving signals from the multi-source status sensing module, the PLC control unit performs data filtering, logical judgment, and threshold alarm. Data filtering adopts a first-order inertial filtering algorithm with a filtering coefficient α=0.2. The filtering formula is Y(n)=α×X(n)+(1-α)×Y(n-1), where X(n) is the current sampled value, Y(n) is the current filtered output value, and Y(n-1) is the filtered output value at the previous moment. Logical judgment includes threshold judgment, trend judgment, and deviation judgment. Threshold judgment includes: triggering a high-pressure alarm when the P port pressure of the digitally controlled integrated high-frequency response proportional servo valve is >35MPa, triggering a low-pressure alarm when the P port pressure is <0.5MPa, and triggering a low-pressure alarm when the digitally controlled integrated high-frequency response proportional servo valve... A high-pressure alarm is triggered when the pressure at port A or B of the servo valve exceeds 31.5 MPa; a differential pressure alarm is triggered when the differential pressure at port PA exceeds 5 MPa or the differential pressure at port PB exceeds 5 MPa; a voltage abnormality alarm is triggered when the main valve command voltage deviation exceeds ±0.5V; a current abnormality alarm is triggered when the coil drive current is <0.1A or >2.5A; and a high-temperature alarm is triggered when the valve body temperature exceeds 80℃. Trend judgment includes: a pressure change alarm is triggered when the pressure change within 1 minute exceeds 5 MPa; and a temperature change alarm is triggered when the temperature change within 10 minutes exceeds 10℃. Deviation judgment includes: a main valve tracking abnormality alarm is triggered when the deviation between the main valve command voltage and the main valve feedback voltage exceeds ±0.3V; and a pilot valve tracking abnormality alarm is triggered when the deviation between the pilot valve command voltage and the pilot valve feedback voltage exceeds ±0.2V.

[0013] The host computer visualization platform runs on an industrial control computer and communicates with the PLC control unit via the Profinet bus. The host computer visualization platform includes a dynamic display area for the hydraulic system schematic diagram, a real-time data bar, a valve status indicator area, a historical trend curve window, an alarm pop-up prompt area, and a health and maintenance statistics area. The dynamic display area for the hydraulic system schematic diagram draws the hydraulic system schematic diagram of the 45MN high-speed forging machine in vector graphics, including the main pump group, the proportional control unit reconfigured hydraulic control valve group, the main hydraulic cylinder, the charging valve, the accumulator, the cooler, and the oil tank. The valve status indicator area uses seven colors to indicate the working status of the valve group: green indicates normal operation, red indicates fault shutdown, yellow indicates warning status, purple indicates debugging status, blue indicates standby status, cyan indicates maintenance status, and gray indicates offline status.

[0014] The fault diagnosis and rapid processing module incorporates a fault tree analysis model and an expert rule base. The fault tree analysis model uses system faults as the top event, proportional valve faults, cartridge valve faults, relief valve faults, sensor faults, and oil faults as intermediate events, and specific fault modes as bottom events to construct logical relationships. The expert rule base includes the following diagnostic rules: Rule 1: When the main valve command deviation is > ±0.3V and the coil drive current is <0.1A, the diagnosis result is that the proportional valve coil is open-circuited. The handling steps are to check the coil wiring, measure the coil resistance, and replace the coil or valve. The spare parts list is 1 proportional servo valve coil. Rule 2: When the main valve command deviation is > ±0.3V and the coil drive current is > 2.5A, the diagnosis result is a short circuit in the proportional valve coil. The handling steps are to check the coil insulation, measure the coil resistance, and replace the coil or valve. The spare parts list is 1 proportional servo valve coil. Rule 3: When the pressure at port P of the digitally controlled integrated high-frequency response proportional servo valve is >35MPa and the pressure at port A is <5MPa, the diagnosis result is that the main valve core of the proportional valve is stuck. The handling steps are to check the cleanliness of the oil, disassemble and inspect the valve core, clean or replace the valve core, and the spare parts list is proportional servo valve core ×1. Rule 4: When the differential pressure at the PA port of the digitally controlled integrated high-frequency response proportional servo valve is <0.5MPa and the main valve core opening is >50%, the diagnosis result is that the proportional valve has serious internal leakage. The handling steps are to check the valve core wear, check the seals, and replace the seals or valve parts. The spare parts list is 1 proportional servo valve sealing kit. Rule 5: When the valve body temperature is >80℃ and the temperature change rate is >1℃ / min, the diagnosis result is abnormal valve group temperature rise. The handling steps are to check the cooling system, check the oil viscosity, reduce the working frequency, and the spare parts list is cooler filter element ×1. Rule 6: When the pressure sensor outputs <4mA or >20mA, the diagnosis is a pressure sensor failure. The troubleshooting steps are to check the sensor wiring, check the sensor power supply, and replace the sensor. The spare parts list is 1 pressure sensor. Rule 7: When the displacement sensor outputs <4mA or >20mA, the diagnosis result is a displacement sensor failure. The handling steps are to check the sensor wiring, check the magnetic ring position, and replace the sensor. The spare parts list is 1 displacement sensor. Rule 8: When the differential pressure sensor outputs <4mA or >20mA, the diagnosis result is a differential pressure sensor failure. The troubleshooting steps are to check the sensor wiring, check for blockages at the pressure tap, and replace the sensor. The spare parts list is 1 differential pressure sensor. Rule 9: When the pressure before the valve is <0.5MPa and the main pump is running, the diagnosis result is insufficient oil supply pressure. The handling steps are to check the main pump suction port, check for filter blockage, check for internal leakage of the pump, and the spare parts list is 1 main pump seal. Rule 10: When the cumulative working time is >8760h and the valve core opening response time is >15ms, the diagnosis result is that the proportional valve is aging and worn. The handling steps are to assess the valve core wear, replace the valve core or the whole valve, and recalibrate. The spare parts list is 1 proportional servo valve.

[0015] The diagnostic process of the fault diagnosis and rapid processing module includes real-time acquisition of multi-source status data, data filtering and threshold judgment, anomaly identification and graded early warning, fault tree FTA reasoning, expert rule base matching, precise fault point location, output of processing solutions and steps, on-site execution and parameter verification, fault closure and record archiving, and pushing processing steps and spare parts list to the operation terminal.

[0016] The host computer visualization platform supports historical curve playback, data report generation, and alarm pop-up notifications.

[0017] The second technical solution adopted in this invention is a method for reconstructing and diagnosing the fault of the proportional control unit of the hydraulic system of a high-speed forging mill, comprising the following steps: Step 1: Measure and map the original valve group in the hydraulic system of the 45MN high-speed forging machine to determine the installation dimensions, flow and pressure characteristics, and control signal type, and complete the equivalent selection of the digital proportional valve; Step 2: Reconstruct the hydraulic control valve group with the proportional control unit to directly replace the original valve group, optimize the valve block flow channel and damping parameters, and complete the no-load debugging, pressure holding test and continuous forging reliability verification. Step 3: The hydraulic system's operating pressure, differential pressure, voltage, current, displacement, and temperature signals are collected in real time through the multi-source status sensing module and transmitted to the PLC control unit. Step 4: The PLC control unit processes the received signals and uploads them to the host computer. The host computer's visualization platform then displays the hydraulic system's operating status. Step 5: When parameters are out of tolerance or the status is abnormal, the fault diagnosis and rapid processing module starts fault tree reasoning and expert rule matching to automatically identify hydraulic system faults and quickly locate the fault point. Step 6: The system outputs diagnostic conclusions, troubleshooting steps, and a spare parts list to guide operators in completing rapid handling and forming a closed-loop record.

[0018] The beneficial effects of this invention are as follows: (1) By reconstructing the hydraulic control valve group with a proportional control unit, the original valve group in the hydraulic system of the 45MN fast forging machine is directly replaced. The interface is equivalently matched and there is no need to modify the pipeline. The original valve group is an imported valve group, which has high procurement costs and long delivery cycle. The proportional control unit proposed in this invention reconstructs the hydraulic control valve group with a domestic valve group, which is independently controllable. Compared with the existing foreign valve group, the procurement cost can be reduced by about 40% and the delivery cycle can be shortened by about 57%. The original analog control split valve is replaced with a digitally controlled integrated high-frequency response proportional servo valve, realizing 100% proportional control unit reconstruction and replacement of the core hydraulic control valve of the 45MN fast forging machine. There is no need to modify the valve block and pipeline, get rid of the dependence on the analog control split valve, and reduce the operation and maintenance cost by more than 40%. (2) The hydraulic system operating parameters are collected in real time through the multi-source state perception module and transmitted to the PLC control unit for data processing. Data interaction is performed with the host computer, and the hydraulic system operating status is dynamically visualized through the host computer visualization platform. The real-time working status of valves, pumps, pipelines and oil is displayed intuitively, which improves the management level of the equipment. (3) The fault diagnosis and rapid processing module automatically identifies hydraulic system faults and outputs diagnostic conclusions and processing steps, which shortens the fault location time of the hydraulic system of the high-speed forging machine from hours to less than 5 minutes and reduces downtime by more than 30%. (4) The system has strong compatibility and can be directly modified on the existing 45MN fast forging machine without major changes to the mechanical structure and hydraulic pipeline. The proportional control unit reconstructs the hydraulic control valve group with a rated pressure ≥35MPa, response time ≤10ms, control accuracy ±0.1%, and anti-pollution level reaches NAS 8. (5) It has data storage, trend analysis and maintenance reminder functions, and can be upgraded to predictive maintenance. Attached Figure Description

[0019] Figure 1 This is a structural block diagram of the proportional control unit reconfiguration and fault diagnosis system for the hydraulic system of a high-speed forging mill according to the present invention; Figure 2 This is a logic block diagram of the PLC control unit performing data processing in the proportional control unit reconfiguration and fault diagnosis system of the hydraulic system of the high-speed forging machine of the present invention; Figure 3 This is a schematic diagram of the upper computer visualization platform interface in the hydraulic system proportional control unit reconstruction and fault diagnosis system of the high-speed forging machine of the present invention; Figure 4 This is a schematic diagram of the fault tree analysis model in the reconstructing and fault diagnosis system of the proportional control unit of the hydraulic system of the high-speed forging machine of the present invention; Figure 5 This is a flowchart of fault diagnosis and rapid processing in the proportional control unit reconfiguration and fault diagnosis system of the hydraulic system of the high-speed forging machine of the present invention. Detailed Implementation

[0020] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0021] Example 1 See Figure 1A proportional control unit reconfiguration and fault diagnosis system for a high-speed forging machine hydraulic system includes a proportional control unit reconfigured hydraulic control valve group, a multi-source status sensing module, a PLC control unit, a host computer visualization platform, and a fault diagnosis and rapid processing module. The proportional control unit reconfigured hydraulic control valve group directly replaces the valve group in the original hydraulic system of the 45MN high-speed forging machine. The proportional control unit reconfigured hydraulic control valve group includes a digitally controlled integrated high-frequency response proportional servo valve, a large-flow logic cartridge valve, a pilot-operated proportional relief valve, and a safety valve. It is completely equivalent to the original valve group in the high-speed forging machine hydraulic system in terms of installation interface, control signal, and pressure and flow parameters.

[0022] The proportional control valve for the main hydraulic cylinder in the existing 45MN high-speed forging machine hydraulic system is a Rexroth 4WRPEH 10 C3B100L-2X / G24K0 / A1M high-frequency response proportional servo valve. This valve has a separate analog control structure, with the valve and control system set up separately, which is time-consuming and labor-intensive to maintain. The valve has a rated working pressure of 31.5MPa, a rated flow of 100L / min, a response time of about 15ms, and uses ±10V analog control signals. The installation interface conforms to the ISO 4401-05 standard.

[0023] In this embodiment, the digitally controlled integrated high-frequency response proportional servo valve selected is the Hengli Hydraulics 2WRCVE 32 B100L-2X / G24K0 / A1M type digitally controlled integrated high-frequency response proportional servo valve. This valve has a rated working pressure of 35MPa (+), a rated flow rate of 100L / 400L / min, a response time ≤10ms, and a control accuracy of ±0.1%. It adopts a CANopen bus digital communication interface and is also compatible with ±10V analog control signals. The installation interface conforms to the ISO 4401-05 standard. It is used to directly replace the original 4WRPEH series high-frequency response proportional servo valve. The replacement process is as follows: (1) Turn off the main power supply of the hydraulic system and release the system pressure to zero; (2) Remove the original Rexroth 4WRPEH proportional servo valve and record the original valve installation direction, pipeline connection method and electrical wiring; (3) Clean the valve block mounting surface and check that the flatness of the mounting surface is ≤0.01mm; (4) Install the Hengli 2WRCVE proportional servo valve. Note that the valve installation direction is consistent with the original valve. The tightening bolt torque is as specified by the manufacturer (M8 bolt torque 25 N·m). (5) Connect the hydraulic pipeline. The P port of the digitally controlled integrated high-frequency response proportional servo valve is connected to the system pressure oil, the A and B ports are connected to the two chambers of the hydraulic cylinder, and the T port is connected to the return oil. (6) Connect the electrical circuit, connect the ±10V analog control signal to the control terminal of the valve, and connect the CANopen communication line to the communication terminal of the valve. (7) Start the hydraulic system and perform no-load testing to check the valve's direction of movement, zero-point drift, and linearity; (8) Conduct a pressure holding test. The system pressure is raised to 31.5MPa and held for 10 minutes. Check that there is no leakage at each sealing surface. (9) Conduct continuous forging reliability verification, run continuously for 8 hours, forging frequency 60 times / minute, and check the working stability and temperature rise of the valve.

[0024] Tests showed that the replaced Hengli 2WRCVE proportional servo valve met or even surpassed the original Rexroth valve in terms of response time, control accuracy, and stability, meeting the process requirements of the 45MN high-speed forging machine. Moreover, it eliminated the reliance on separate analog control units, reducing maintenance costs by more than 40%.

[0025] The high-flow logic cartridge valve adopts Hengli Hydraulics LC series cartridge valves, with a nominal diameter of NG63, a rated working pressure of 31.5MPa, a rated flow rate of 2000L / min, and a proportional pilot control method. The installation interface conforms to ISO 7368 standards and is used to directly replace the original Rexroth LC series cartridge valves in the hydraulic system of the 45MN high-speed forging machine. The pilot-operated proportional relief valve adopts Hengli Hydraulics DBE series valves (supply cycle 2-4 months), with a rated working pressure of 31.5MPa, a pressure adjustment range of 0.5MPa~31.5MPa, and adopts a CANopen bus digital communication interface. The installation interface conforms to ISO 6264 standards and is used to replace the original Rexroth DBE series proportional relief valves in the hydraulic system of the 45MN high-speed forging machine (supply cycle 6-12 months).

[0026] The multi-source state perception module is used to collect hydraulic system operating parameters in real time. The PLC control unit is used to receive the signals collected by the multi-source state perception module, complete data processing, and interact with the host computer. The host computer visualization platform is used to realize dynamic visualization of the hydraulic system operating status. The fault diagnosis and rapid processing module has a built-in fault tree analysis model and expert rule base, which can automatically identify hydraulic system faults and output diagnostic conclusions and processing steps.

[0027] Example 2 A proportional control unit reconfiguration and fault diagnosis system for a high-speed forging machine hydraulic system includes a proportional control unit reconfigured hydraulic control valve group, a multi-source status sensing module, a PLC control unit, a host computer visualization platform, and a fault diagnosis and rapid processing module. The proportional control unit reconfigured hydraulic control valve group directly replaces the valve group in the original hydraulic system of the 45MN high-speed forging machine. The proportional control unit reconfigured hydraulic control valve group includes a digitally controlled integrated high-frequency response proportional servo valve, a large-flow logic cartridge valve, a pilot-operated proportional relief valve, and a safety valve. It is completely equivalent to and matches the original valve group in the high-speed forging machine hydraulic system in terms of installation interface, control signal, and pressure and flow parameters. The proportional control valve for the main hydraulic cylinder in the existing 45MN high-speed forging machine hydraulic system is a Rexroth 4WRPEH 10 C3B100L-2X / G24K0 / A1M high-frequency response proportional servo valve. This valve has a separate analog control structure, with the valve and control system set up separately, which makes operation and maintenance relatively troublesome. The rated working pressure of this valve is 31.5MPa, the rated flow rate is 100L / min, the response time is about 15ms, it uses ±10V analog control signal, and the installation interface conforms to the ISO 4401-05 standard.

[0028] In this embodiment, the digitally controlled integrated high-frequency response proportional servo valve selected is the Hengli Hydraulics 2WRCVE 32 B100L-2X / G24K0 / A1M type digitally controlled integrated high-frequency response proportional servo valve. This valve has a rated working pressure of 35MPa, a rated flow rate of 100L / min, a response time ≤10ms, and a control accuracy of ±0.1%. It adopts a CANopen bus digital communication interface and is also compatible with ±10V analog control signals. The installation interface conforms to the ISO 4401-05 standard. It is used to directly replace the original 4WRPEH series high-frequency response proportional servo valve. The replacement process is as follows: (1) Turn off the main power supply of the hydraulic system and release the system pressure to zero; (2) Remove the original Rexroth 4WRPEH proportional servo valve and record the original valve installation direction, pipeline connection method and electrical wiring; (3) Clean the valve block mounting surface and check that the flatness of the mounting surface is ≤0.01mm; (4) Install the Hengli 2WRCVE proportional servo valve. Note that the valve installation direction is consistent with the original valve. The tightening bolt torque is as specified by the manufacturer (M8 bolt torque 25 N·m). (5) Connect the hydraulic pipeline. The P port of the digitally controlled integrated high-frequency response proportional servo valve is connected to the system pressure oil, the A and B ports are connected to the two chambers of the hydraulic cylinder, and the T port is connected to the return oil. (6) Connect the electrical circuit, connect the ±10V analog control signal to the control terminal of the valve, and connect the CANopen communication line to the communication terminal of the valve. (7) Start the hydraulic system and perform no-load testing to check the valve's direction of movement, zero-point drift, and linearity; (8) Conduct a pressure holding test. The system pressure is raised to 31.5MPa and held for 10 minutes. Check that there is no leakage at each sealing surface. (9) Conduct continuous forging reliability verification, run continuously for 8 hours, forging frequency 60 times / minute, and check the working stability and temperature rise of the valve.

[0029] Table of Replacement Parameters for Proportional Control Valves in the Hydraulic System of a 45MN High-Speed ​​Forging Mill:

[0030] Tests show that the reconfiguration rate of the core control valve proportional control unit of this invention is ≥100%, the fault location time is ≤5 minutes, the equipment downtime is reduced by ≥30%, and the operation and maintenance cost is reduced by more than 40%.

[0031] The high-flow logic cartridge valve adopts the Hengli Hydraulics LC series cartridge valve, with a nominal diameter of NG63, a rated working pressure of 31.5MPa, a rated flow rate of 2000L / min, and a proportional pilot control method. The installation interface conforms to the ISO 7368 standard and is used to directly replace the original Rexroth LC series cartridge valve in the hydraulic system of the 45MN high-speed forging machine. The pilot-operated proportional relief valve adopts the Hengli Hydraulics DBE series valve, with a rated working pressure of 31.5MPa, a pressure adjustment range of 0.5MPa~31.5MPa, and adopts the CANopen bus digital communication interface. The installation interface conforms to the ISO 6264 standard and is used to replace the original Rexroth DBE series proportional relief valve in the hydraulic system of the 45MN high-speed forging machine.

[0032] The multi-source status sensing module includes a pressure sensor, a differential pressure sensor, a voltage acquisition module, a current acquisition module, a displacement sensor, a temperature sensor, and a timing module, which are used to collect hydraulic system operating parameters in real time.

[0033] In this embodiment, the pressure sensor used is a Hydac HDA 4700-A-0400-000 model pressure sensor with a G1 / 4" threaded interface, a range of 0–40 MPa, an accuracy of ±0.25%FS, and an output signal of 4mA–20mA. It is installed on the P, A, B, and T ports of the digitally controlled integrated high-frequency response proportional servo valve. During installation, please note: (1) Before installing the sensor, check the cleanliness of the pressure tap to ensure that there are no metal shavings or impurities; (2) The sensor installation torque shall be in accordance with the manufacturer’s specifications (G1 / 4" interface torque 20 N·m). (3) The sensor signal line uses a shielded cable, and the shielding layer is grounded at one end; (4) The sensor is powered by 24VDC, which is provided by the PLC power supply module.

[0034] The differential pressure sensor is a Hydac HDA 4745-A-0005-000 model differential pressure sensor with a range of 0 to 5 MPa, an accuracy of ±0.5%FS, and an output signal of 4mA to 20mA. It is installed between the P port and the A port, and between the P port and the B port of the digitally controlled integrated high-frequency response proportional servo valve. Both the voltage and current acquisition modules use Siemens SM 1231 analog input modules with 16-bit resolution and a sampling period of ≤10ms, capable of simultaneously acquiring 8 channels of analog signals. The voltage acquisition module is used to acquire the main valve command voltage signal (±10V), main valve feedback voltage signal (±10V), pilot valve command voltage signal (±10V), and pilot valve feedback voltage signal (±10V) of the digitally controlled integrated high-frequency response proportional servo valve; the current acquisition module is used to acquire the coil drive current signal (0-2.5A) of the digitally controlled integrated high-frequency response proportional servo valve. The displacement sensor is a Balluff BTL5-E10-M0100-P-S32 magnetostrictive displacement sensor with a range of 0-100mm, an accuracy of ±0.01mm, and an output signal of 4mA-20mA. It is installed on the valve core position detection end of the digitally controlled integrated high-frequency response proportional servo valve to monitor the opening degree of the main valve core in real time.

[0035] The temperature sensor is a Hydac ETS 3800-100-000 model, with a range of -25℃ to 100℃, an accuracy of ±0.5℃, and an output signal of 4mA to 20mA. It is installed on the valve body surface of the digitally controlled integrated high-frequency response proportional servo valve for real-time monitoring of the valve assembly's operating temperature. The timing module is integrated into the PLC control unit and is used to count the cumulative operating time of the valve assembly.

[0036] After installing the above sensors, each sensor needs to be debugged. The debugging process is as follows: (1) Check that all sensors are securely installed and that the wiring is correct; (2) Power on the sensor and check that the output signal is within the range; (3) Configure the analog input channel in the PLC and set the range conversion parameters; (4) Perform zero-point calibration and full-scale calibration; (5) Conduct dynamic response tests to check the sampling period and filtering effect.

[0037] The PLC control unit receives signals collected by the multi-source status sensing module, processes the data, and interacts with the host computer. The CPU processor in the PLC control unit is a CPU 1214C DC / DC / DC, integrating a Profinet communication interface. After receiving signals from the multi-source status sensing module, the PLC control unit performs data filtering, logical judgment, and threshold alarm. Data filtering uses a first-order inertial filtering algorithm with a filtering coefficient α=0.2. The filtering formula is Y(n)=α×X(n)+(1-α)×Y(n-1), where X(n) is the current sampled value, Y(n) is the current filtered output value, and Y(n-1) is the filtered output value from the previous moment. Logic judgment includes threshold judgment, trend judgment, and deviation judgment. Threshold judgment includes: triggering a high-pressure alarm when the P-port pressure of the digitally controlled integrated high-frequency response proportional servo valve is >35MPa, triggering a low-pressure alarm when the P-port pressure is <0.5MPa, and triggering a low-pressure alarm when the digitally controlled integrated high-frequency response proportional servo valve... A high-pressure alarm is triggered when the pressure at port A or B of the servo valve exceeds 31.5 MPa; a differential pressure alarm is triggered when the differential pressure at port PA exceeds 5 MPa or the differential pressure at port PB exceeds 5 MPa; a voltage abnormality alarm is triggered when the main valve command voltage deviation exceeds ±0.5V; a current abnormality alarm is triggered when the coil drive current is <0.1A or >2.5A; and a high-temperature alarm is triggered when the valve body temperature exceeds 80℃. Trend judgment includes: a pressure change alarm is triggered when the pressure change within 1 minute exceeds 5 MPa; and a temperature change alarm is triggered when the temperature change within 10 minutes exceeds 10℃. Deviation judgment includes: a main valve tracking abnormality alarm is triggered when the deviation between the main valve command voltage and the main valve feedback voltage exceeds ±0.3V; and a pilot valve tracking abnormality alarm is triggered when the deviation between the pilot valve command voltage and the pilot valve feedback voltage exceeds ±0.2V.

[0038] The host computer visualization platform is used to realize the dynamic visualization display of the hydraulic system's operating status. The fault diagnosis and rapid processing module has a built-in fault tree analysis model and expert rule base, which can automatically identify hydraulic system faults and output diagnostic conclusions and processing steps.

[0039] Example 3 A proportional control unit reconfiguration and fault diagnosis system for a high-speed forging machine hydraulic system includes a proportional control unit reconfigured hydraulic control valve group, a multi-source status sensing module, a PLC control unit, a host computer visualization platform, and a fault diagnosis and rapid processing module. The proportional control unit reconfigured hydraulic control valve group directly replaces the valve group in the original hydraulic system of the 45MN high-speed forging machine. The proportional control unit reconfigured hydraulic control valve group includes a digitally controlled integrated high-frequency response proportional servo valve, a large-flow logic cartridge valve, a pilot-operated proportional relief valve, and a safety valve. It is completely equivalent to and matches the original valve group in the high-speed forging machine hydraulic system in terms of installation interface, control signal, and pressure and flow parameters. The proportional control valve for the main hydraulic cylinder in the existing 45MN high-speed forging machine hydraulic system is a Rexroth 4WRPEH 10 C3B100L-2X / G24K0 / A1M high-frequency response proportional servo valve. This valve has a separate analog control structure, with the valve and control system set up separately, which makes operation and maintenance relatively troublesome. The rated working pressure of this valve is 31.5MPa, the rated flow rate is 100L / min, the response time is about 15ms, it uses ±10V analog control signal, and the installation interface conforms to the ISO 4401-05 standard.

[0040] In this embodiment, the digitally controlled integrated high-frequency response proportional servo valve is the Hengli Hydraulic 2WRCVE series valve. This valve has a rated working pressure of 35MPa, a rated flow rate of 100L / min, a response time ≤10ms, and a control accuracy of ±0.1%. It uses a CANopen bus digital communication interface and is also compatible with ±10V analog control signals. The installation interface conforms to the ISO 4401-05 standard. It is used to directly replace the original 4WRPEH series high-frequency response proportional servo valve. During replacement, the hydraulic lines are connected, with the P port of the digitally controlled integrated high-frequency response proportional servo valve connected to the system pressure oil, the A and B ports connected to the two chambers of the hydraulic cylinder, and the T port connected to the return oil. Electrical connections are also made, with the ±10V analog control signal connected to the valve's control terminals, and the CANopen communication line connected to the valve's communication terminals. Tests showed that the replaced Hengli 2WRCVE proportional servo valve met or even surpassed the original Rexroth valve in terms of response time, control accuracy, and stability, meeting the process requirements of the 45MN high-speed forging machine. Moreover, it eliminated the reliance on separate analog control units, reducing maintenance costs by more than 40%.

[0041] The high-flow logic cartridge valve adopts the Hengli Hydraulics LC series cartridge valve, with a nominal diameter of NG63, a rated working pressure of 31.5MPa, a rated flow rate of 2000L / min, and a proportional pilot control method. The installation interface conforms to the ISO 7368 standard and is used to directly replace the original Rexroth LC series cartridge valve in the hydraulic system of the 45MN high-speed forging machine. The pilot-operated proportional relief valve adopts the Hengli Hydraulics DBE series valve, with a rated working pressure of 31.5MPa, a pressure adjustment range of 0.5MPa~31.5MPa, and adopts the CANopen bus digital communication interface. The installation interface conforms to the ISO 6264 standard and is used to replace the original Rexroth DBE series proportional relief valve in the hydraulic system of the 45MN high-speed forging machine.

[0042] The multi-source status sensing module includes a pressure sensor, a differential pressure sensor, a voltage acquisition module, a current acquisition module, a displacement sensor, a temperature sensor, and a timing module, which are used to collect hydraulic system operating parameters in real time.

[0043] In this embodiment, the pressure sensor used is the Hydac HDA 4700 series pressure sensor, with a G1 / 4" threaded interface, a range of 0 to 40 MPa, an accuracy of ±0.25%FS, and an output signal of 4mA to 20mA. It is installed on the P port, A port, B port and T port of the digitally controlled integrated high-frequency response proportional servo valve respectively. The differential pressure sensor uses the Hydac HDA 4745 series differential pressure sensor, with a range of 0 to 5 MPa, an accuracy of ±0.5%FS, and an output signal of 4mA to 20mA. It is installed between the P port and the A port, and between the P port and the B port of the digitally controlled integrated high-frequency response proportional servo valve. Both the voltage and current acquisition modules use Siemens SM 1231 analog input modules with 16-bit resolution and a sampling period of ≤10ms, capable of simultaneously acquiring 8 channels of analog signals. The voltage acquisition module is used to acquire the main valve command voltage signal (±10V), main valve feedback voltage signal (±10V), pilot valve command voltage signal (±10V), and pilot valve feedback voltage signal (±10V) of the digitally controlled integrated high-frequency response proportional servo valve; the current acquisition module is used to acquire the coil drive current signal (0-2.5A) of the digitally controlled integrated high-frequency response proportional servo valve. The displacement sensor adopts the Balluff BTL series magnetostrictive displacement sensor, with a range of 0 to 100 mm, an accuracy of ±0.01 mm, and an output signal of 4 mA to 20 mA. It is installed on the valve core position detection end of the digitally controlled integrated high-frequency response proportional servo valve to monitor the opening degree of the main valve core in real time.

[0044] The temperature sensor uses a Hydac ETS 3800 series temperature sensor with a range of -25℃ to 100℃, an accuracy of ±0.5℃, and an output signal of 4mA to 20mA. It is installed on the valve body surface of the digitally controlled integrated high-frequency response proportional servo valve for real-time monitoring of the valve group's operating temperature. The timing module is integrated into the PLC control unit and is used to count the cumulative operating time of the valve group.

[0045] After installing the above sensors, each sensor should be debugged to match its parameters with the actual working conditions. See Figure 2 The PLC control unit adopts Siemens S7-1200 series PLC, with CPU model CPU 1214C DC / DC / DC. It integrates 14 digital inputs, 10 digital outputs, 2 analog inputs and 2 analog outputs, and integrates a Profinet communication interface to receive signals collected by the multi-source status sensing module, complete data processing, and interact with the host computer.

[0046] The PLC program adopts a modular design, including the main program (OB1), data acquisition program (FC1), data filtering program (FC2), threshold judgment program (FC3), trend judgment program (FC4), deviation judgment program (FC5), alarm output program (FC6), and communication program (FC7).

[0047] Data Acquisition Program (FC1) Functions: (1) Read the analog input values ​​of each sensor and convert them into engineering units (MPa, ℃, mm, etc.). (2) Read the CANopen communication data of the digitally controlled integrated high-frequency response proportional servo valve, including the main valve command signal, the main valve feedback signal, the pilot valve command signal, and the pilot valve feedback signal; (3) Calculate the main valve command deviation and the pilot valve command deviation; (4) Statistical valve group cumulative working time.

[0048] Data filtering program (FC2) functions: A first-order inertial filtering algorithm is used, with filtering coefficient α = 0.2, and the filtering formula is as follows: Y(n) = α × X(n) + (1-α) × Y(n-1) Where X(n) is the current sampled value, Y(n) is the current filtered output value, and Y(n-1) is the filtered output value at the previous time step.

[0049] Threshold determination program (FC3) functions: (1) Valve inlet pressure threshold judgment: IF P port pressure > 35MPa THEN triggers high pressure alarm; IF P port pressure < 0.5MPa THEN triggers low pressure alarm; (2) Valve downstream pressure threshold judgment: IF A port pressure > 31.5MPa OR B port pressure > 31.5MPa THEN trigger high pressure alarm; (3) Differential pressure threshold judgment: IF PA port differential pressure > 5MPa OR PB port differential pressure > 5MPa THEN trigger differential pressure alarm; (4) Voltage threshold judgment: IF |Main valve command voltage - main valve feedback voltage| > 0.5V THEN trigger voltage abnormality alarm; (5) Current threshold judgment: IF coil drive current < 0.1A OR coil drive current > 2.5A THEN trigger current abnormality alarm; (6) Temperature threshold judgment: IF valve body temperature > 80℃ THEN trigger high temperature alarm.

[0050] Trend Analysis Program (FC4) Functionality: (1) Pressure change rate judgment: Calculate the pressure change value ΔP within 1 minute. If ΔP>5MPa, trigger the pressure change alarm. (2) Temperature change rate judgment: Calculate the temperature change value ΔT within 10 minutes. If ΔT>10℃, then trigger the temperature change alarm.

[0051] Deviation detection program (FC5) functions: (1) Judgment of main valve command deviation: IF |main valve command voltage - main valve feedback voltage|>0.3V THEN Trigger main valve tracking abnormal alarm; (2) Pilot valve command deviation judgment: IF |pilot valve command voltage - pilot valve feedback voltage|>0.2V THEN trigger pilot valve tracking abnormal alarm.

[0052] Alarm Output Program (FC6) Functions: (1) Output alarm signals according to the alarm level: Level 1 warning (yellow indicator light), Level 2 warning (orange indicator light), Level 3 alarm (red indicator light and buzzer); (2) Record the alarm time, alarm type, and alarm parameter values; (3) Send the alarm information to the host computer via the Profinet bus.

[0053] Communication program (FC7) functions: (1) Data interaction with the host computer is performed via the Profinet bus, with a transmission cycle of 100ms; (2) Communicate with the digitally controlled integrated high-frequency response proportional servo valve via CANopen bus, with a transmission cycle of 10ms; (3) Data packaging format: Device number (2 bytes) + Parameter type (2 bytes) + Parameter value (4-byte floating-point number) + Timestamp (4 bytes).

[0054] The host computer visualization platform is used to realize the dynamic visualization display of the hydraulic system's operating status. The fault diagnosis and rapid processing module has a built-in fault tree analysis model and expert rule base, which can automatically identify hydraulic system faults and output diagnostic conclusions and processing steps.

[0055] Example 4 A proportional control unit reconfiguration and fault diagnosis system for a high-speed forging machine hydraulic system includes a proportional control unit reconfigured hydraulic control valve group, a multi-source status sensing module, a PLC control unit, a host computer visualization platform, and a fault diagnosis and rapid processing module. The proportional control unit reconfigured hydraulic control valve group directly replaces the valve group in the original hydraulic system of the 45MN high-speed forging machine. The proportional control unit reconfigured hydraulic control valve group includes a digitally controlled integrated high-frequency response proportional servo valve, a large-flow logic cartridge valve, a pilot-operated proportional relief valve, and a safety valve. It is completely equivalent to and matches the original valve group in the high-speed forging machine hydraulic system in terms of installation interface, control signal, and pressure and flow parameters. The proportional control valve for the main hydraulic cylinder in the existing 45MN high-speed forging machine hydraulic system is a Rexroth 4WRPEH 10 C3B100L-2X / G24K0 / A1M high-frequency response proportional servo valve. This valve has a separate analog control structure, with the valve and control system set up separately, which makes operation and maintenance relatively troublesome. The rated working pressure of this valve is 31.5MPa, the rated flow rate is 100L / min, the response time is about 15ms, it uses ±10V analog control signal, and the installation interface conforms to the ISO 4401-05 standard.

[0056] In this embodiment, the digitally controlled integrated high-frequency response proportional servo valve selected is the Hengli Hydraulics 2WRCVE 32 B100L-2X / G24K0 / A1M type digitally controlled integrated high-frequency response proportional servo valve. This valve has a rated working pressure of 35MPa, a rated flow rate of 100L / min, a response time ≤10ms, and a control accuracy of ±0.1%. It adopts a CANopen bus digital communication interface and is also compatible with ±10V analog control signals. The installation interface conforms to the ISO 4401-05 standard. It is used to directly replace the original 4WRPEH series high-frequency response proportional servo valve. The replacement process is as follows: (1) Turn off the main power supply of the hydraulic system and release the system pressure to zero; (2) Remove the original Rexroth 4WRPEH proportional servo valve and record the original valve installation direction, pipeline connection method and electrical wiring; (3) Clean the valve block mounting surface and check that the flatness of the mounting surface is ≤0.01mm; (4) Install the Hengli 2WRCVE proportional servo valve. Note that the valve installation direction is consistent with the original valve. The tightening bolt torque is as specified by the manufacturer (M8 bolt torque 25 N·m). (5) Connect the hydraulic pipeline. The P port of the digitally controlled integrated high-frequency response proportional servo valve is connected to the system pressure oil, the A and B ports are connected to the two chambers of the hydraulic cylinder, and the T port is connected to the return oil. (6) Connect the electrical circuit, connect the ±10V analog control signal to the control terminal of the valve, and connect the CANopen communication line to the communication terminal of the valve. (7) Start the hydraulic system and perform no-load testing to check the valve's direction of movement, zero-point drift, and linearity; (8) Conduct a pressure holding test. The system pressure is raised to 31.5MPa and held for 10 minutes. Check that there is no leakage at each sealing surface. (9) Conduct continuous forging reliability verification, run continuously for 8 hours, forging frequency 60 times / minute, and check the working stability and temperature rise of the valve.

[0057] Tests showed that the replaced Hengli 2WRCVE proportional servo valve met or even surpassed the original Rexroth valve in terms of response time, control accuracy, and stability, meeting the process requirements of the 45MN high-speed forging machine. Moreover, it eliminated the reliance on separate analog control units, reducing maintenance costs by more than 40%.

[0058] The high-flow logic cartridge valve adopts the Hengli Hydraulics LC series cartridge valve, with a nominal diameter of NG63, a rated working pressure of 31.5MPa, a rated flow rate of 2000L / min, and a proportional pilot control method. The installation interface conforms to the ISO 7368 standard and is used to directly replace the original Rexroth LC series cartridge valve in the hydraulic system of the 45MN high-speed forging machine. The pilot-operated proportional relief valve adopts the Hengli Hydraulics DBE series valve, with a rated working pressure of 31.5MPa, a pressure adjustment range of 0.5MPa~31.5MPa, and adopts the CANopen bus digital communication interface. The installation interface conforms to the ISO 6264 standard and is used to replace the original Rexroth DBE series proportional relief valve in the hydraulic system of the 45MN high-speed forging machine.

[0059] The multi-source status sensing module includes a pressure sensor, a differential pressure sensor, a voltage acquisition module, a current acquisition module, a displacement sensor, a temperature sensor, and a timing module, which are used to collect hydraulic system operating parameters in real time.

[0060] In this embodiment, the pressure sensor used is a Hydac HDA 4700-A-0400-000 model pressure sensor with a G1 / 4" threaded interface, a range of 0–40 MPa, an accuracy of ±0.25%FS, and an output signal of 4mA–20mA. It is installed on the P, A, B, and T ports of the digitally controlled integrated high-frequency response proportional servo valve. During installation, please note: (1) Before installing the sensor, check the cleanliness of the pressure tap to ensure that there are no metal shavings or impurities; (2) The sensor installation torque shall be in accordance with the manufacturer’s specifications (G1 / 4" interface torque 20 N·m). (3) The sensor signal line uses a shielded cable, and the shielding layer is grounded at one end; (4) The sensor is powered by 24VDC, which is provided by the PLC power supply module.

[0061] The differential pressure sensor is a Hydac HDA 4745-A-0005-000 model differential pressure sensor with a range of 0 to 5 MPa, an accuracy of ±0.5%FS, and an output signal of 4mA to 20mA. It is installed between the P port and the A port, and between the P port and the B port of the digitally controlled integrated high-frequency response proportional servo valve. Both the voltage and current acquisition modules use Siemens SM 1231 analog input modules with 16-bit resolution and a sampling period of ≤10ms, capable of simultaneously acquiring 8 channels of analog signals. The voltage acquisition module is used to acquire the main valve command voltage signal (±10V), main valve feedback voltage signal (±10V), pilot valve command voltage signal (±10V), and pilot valve feedback voltage signal (±10V) of the digitally controlled integrated high-frequency response proportional servo valve; the current acquisition module is used to acquire the coil drive current signal (0-2.5A) of the digitally controlled integrated high-frequency response proportional servo valve. The displacement sensor is a Balluff BTL5-E10-M0100-P-S32 magnetostrictive displacement sensor with a range of 0-100mm, an accuracy of ±0.01mm, and an output signal of 4mA-20mA. It is installed on the valve core position detection end of the digitally controlled integrated high-frequency response proportional servo valve to monitor the opening degree of the main valve core in real time.

[0062] The temperature sensor is a Hydac ETS 3800-100-000 model, with a range of -25℃ to 100℃, an accuracy of ±0.5℃, and an output signal of 4mA to 20mA. It is installed on the valve body surface of the digitally controlled integrated high-frequency response proportional servo valve for real-time monitoring of the valve assembly's operating temperature. The timing module is integrated into the PLC control unit and is used to count the cumulative operating time of the valve assembly.

[0063] After installing the above sensors, each sensor needs to be debugged. The debugging process is as follows: (1) Check that all sensors are securely installed and that the wiring is correct; (2) Power on the sensor and check that the output signal is within the range; (3) Configure the analog input channel in the PLC and set the range conversion parameters; (4) Perform zero-point calibration and full-scale calibration; (5) Conduct dynamic response tests to check the sampling period and filtering effect.

[0064] The PLC control unit receives signals collected by the multi-source status sensing module, processes the data, and interacts with the host computer. The CPU processor in the PLC control unit is a CPU 1214C DC / DC / DC, integrating a Profinet communication interface. After receiving signals from the multi-source status sensing module, the PLC control unit performs data filtering, logical judgment, and threshold alarm. Data filtering uses a first-order inertial filtering algorithm with a filtering coefficient α=0.2. The filtering formula is Y(n)=α×X(n)+(1-α)×Y(n-1), where X(n) is the current sampled value, Y(n) is the current filtered output value, and Y(n-1) is the filtered output value from the previous moment. Logic judgment includes threshold judgment, trend judgment, and deviation judgment. Threshold judgment includes: triggering a high-pressure alarm when the P-port pressure of the digitally controlled integrated high-frequency response proportional servo valve is >35MPa, triggering a low-pressure alarm when the P-port pressure is <0.5MPa, and triggering a low-pressure alarm when the digitally controlled integrated high-frequency response proportional servo valve... A high-pressure alarm is triggered when the pressure at port A or B of the servo valve exceeds 31.5 MPa; a differential pressure alarm is triggered when the differential pressure at port PA exceeds 5 MPa or the differential pressure at port PB exceeds 5 MPa; a voltage abnormality alarm is triggered when the main valve command voltage deviation exceeds ±0.5V; a current abnormality alarm is triggered when the coil drive current is <0.1A or >2.5A; and a high-temperature alarm is triggered when the valve body temperature exceeds 80℃. Trend judgment includes: a pressure change alarm is triggered when the pressure change within 1 minute exceeds 5 MPa; and a temperature change alarm is triggered when the temperature change within 10 minutes exceeds 10℃. Deviation judgment includes: a main valve tracking abnormality alarm is triggered when the deviation between the main valve command voltage and the main valve feedback voltage exceeds ±0.3V; and a pilot valve tracking abnormality alarm is triggered when the deviation between the pilot valve command voltage and the pilot valve feedback voltage exceeds ±0.2V.

[0065] The host computer is an industrial control computer with the following configuration: CPU Intel Core i5-10400, memory 16GB, hard drive 512GB SSD, operating system Windows 10 IoT Enterprise.

[0066] See Figure 3The host computer visualization platform is developed using Siemens WinCC V7.5 configuration software and communicates with the PLC control unit via the Profinet bus. The host computer visualization platform is used to realize the dynamic visualization display of the hydraulic system operation status, including a dynamic display area of ​​the hydraulic system schematic diagram, a real-time data bar, a valve status indicator area, a historical trend curve window, an alarm pop-up prompt area, and a health and maintenance statistics area. The dynamic display area of ​​the hydraulic system schematic diagram draws the hydraulic system schematic diagram of the 45MN high-speed forging machine in vector graphics, including the main pump group (6 main pumps), the proportional control unit reconfigurable hydraulic control valve group (3 groups), the main hydraulic cylinder (3), the filling valve (3), the accumulator (2), the cooler (1), and the oil tank (1). Each component is represented by a standard hydraulic symbol, and the pipeline is represented by a solid line (high pressure pipeline) or a dashed line (return oil pipeline). The component color changes with the status: green for normal operation, red for fault shutdown, yellow for warning status, purple for debugging status, blue for standby status, cyan for maintenance status, and gray for offline status. Clicking on a component will pop up a detailed parameter window, displaying the real-time data and historical trends of that component.

[0067] Real-time data section: (1) Place real-time data labels next to each component in the schematic diagram to display key parameters; (2) Display next to the proportional servo valve: P port pressure, A port pressure, B port pressure, main valve command voltage, main valve feedback voltage, valve core opening degree, valve body temperature; (3) Display near the main pump: pump outlet pressure, pump operating status, and pump cumulative operating time; (4) Display next to the hydraulic cylinder: pressure in the upper chamber of the cylinder, pressure in the lower chamber of the cylinder, and position of the slider.

[0068] Valve status indicator area: (1) Arrange a seven-color status indicator light next to the hydraulic control valve group reconfigured by the proportional control unit; (2) Indicator light color definition: green - normal operation, red - fault shutdown, yellow - warning status, purple - debugging status, blue - standby status, cyan - maintenance status, gray - offline status; (3) Indicator light flashing frequency: always on during normal operation, flashing at 1Hz during warning mode, and flashing at 2Hz during alarm mode.

[0069] Historical trend curve window: (1) Supports displaying up to 8 historical trend curves simultaneously; (2) The time span can be selected as: 1 minute, 5 minutes, 15 minutes, 30 minutes, 1 hour, 4 hours, 8 hours, 24 hours; (3) Curve types include: pressure curve (red), temperature curve (blue), voltage curve (green), current curve (yellow), and displacement curve (purple); (4) Supports curve scaling, translation, data point query and export functions.

[0070] Alarm pop-up notification area: (1) When the system triggers an alarm, an alarm prompt window will automatically pop up; (2) The alarm window displays: alarm time, alarm level, alarm type, alarm parameter value, and alarm description; (3) Provide "Confirm", "Mute", "View Details" and "Processing Guide" buttons; (4) Unconfirmed alarms continue to be displayed, while confirmed alarms are moved to the historical alarm list.

[0071] Health and Operations Statistics Area: (1) Valve group health assessment: The health index (0-100%) is calculated based on the cumulative working time, number of failures, and degree of parameter drift. (2) Maintenance reminders: Maintenance reminders are automatically generated based on the cumulative working hours and the manufacturer's recommended maintenance cycle; (3) Fault statistics: Statistics on fault types, number of faults, and average processing time by month / quarter / year; (4) Spare parts inventory: Displays the inventory quantity of key spare parts and the warning line.

[0072] The fault diagnosis and rapid processing module has a built-in fault tree analysis model and expert rule base, which can automatically identify hydraulic system faults and output diagnostic conclusions and processing steps.

[0073] Example 5 A proportional control unit reconfiguration and fault diagnosis system for a high-speed forging machine hydraulic system includes a proportional control unit reconfigured hydraulic control valve group, a multi-source status sensing module, a PLC control unit, a host computer visualization platform, and a fault diagnosis and rapid processing module. The proportional control unit reconfigured hydraulic control valve group directly replaces the valve group in the original hydraulic system of the 45MN high-speed forging machine. The proportional control unit reconfigured hydraulic control valve group includes a digitally controlled integrated high-frequency response proportional servo valve, a large-flow logic cartridge valve, a pilot-operated proportional relief valve, and a safety valve. It is completely equivalent to and matches the original valve group in the high-speed forging machine hydraulic system in terms of installation interface, control signal, and pressure and flow parameters. The proportional control valve for the main hydraulic cylinder in the existing 45MN high-speed forging machine hydraulic system is a Rexroth 4WRPEH 10 C3B100L-2X / G24K0 / A1M high-frequency response proportional servo valve. This valve has a separate analog control structure, with the valve and control system set up separately, which makes operation and maintenance relatively troublesome. The rated working pressure of this valve is 31.5MPa, the rated flow rate is 100L / min, the response time is about 15ms, it uses ±10V analog control signal, and the installation interface conforms to the ISO 4401-05 standard.

[0074] In this embodiment, the digitally controlled integrated high-frequency response proportional servo valve selected is the Hengli Hydraulics 2WRCVE 32 B100L-2X / G24K0 / A1M type digitally controlled integrated high-frequency response proportional servo valve. This valve has a rated working pressure of 35MPa, a rated flow rate of 100L / min, a response time ≤10ms, and a control accuracy of ±0.1%. It adopts a CANopen bus digital communication interface and is also compatible with ±10V analog control signals. The installation interface conforms to the ISO 4401-05 standard. It is used to directly replace the original 4WRPEH series high-frequency response proportional servo valve. The replacement process is as follows: (1) Turn off the main power supply of the hydraulic system and release the system pressure to zero; (2) Remove the original Rexroth 4WRPEH proportional servo valve and record the original valve installation direction, pipeline connection method and electrical wiring; (3) Clean the valve block mounting surface and check that the flatness of the mounting surface is ≤0.01mm; (4) Install the Hengli 2WRCVE proportional servo valve. Note that the valve installation direction is consistent with the original valve. The tightening bolt torque is as specified by the manufacturer (M8 bolt torque 25 N·m). (5) Connect the hydraulic pipeline. The P port of the digitally controlled integrated high-frequency response proportional servo valve is connected to the system pressure oil, the A and B ports are connected to the two chambers of the hydraulic cylinder, and the T port is connected to the return oil. (6) Connect the electrical circuit, connect the ±10V analog control signal to the control terminal of the valve, and connect the CANopen communication line to the communication terminal of the valve. (7) Start the hydraulic system and perform no-load testing to check the valve's direction of movement, zero-point drift, and linearity; (8) Conduct a pressure holding test. The system pressure is raised to 31.5MPa and held for 10 minutes. Check that there is no leakage at each sealing surface. (9) Conduct continuous forging reliability verification, run continuously for 8 hours, forging frequency 60 times / minute, and check the working stability and temperature rise of the valve.

[0075] Tests showed that the replaced Hengli 2WRCVE proportional servo valve met or even surpassed the original Rexroth valve in terms of response time, control accuracy, and stability, meeting the process requirements of the 45MN high-speed forging machine. Moreover, it eliminated the reliance on separate analog control units, reducing maintenance costs by more than 40%.

[0076] The high-flow logic cartridge valve adopts the Hengli Hydraulics LC series cartridge valve, with a nominal diameter of NG63, a rated working pressure of 31.5MPa, a rated flow rate of 2000L / min, and a proportional pilot control method. The installation interface conforms to the ISO 7368 standard and is used to directly replace the original Rexroth LC series cartridge valve in the hydraulic system of the 45MN high-speed forging machine. The pilot-operated proportional relief valve adopts the Hengli Hydraulics DBE series valve, with a rated working pressure of 31.5MPa, a pressure adjustment range of 0.5MPa~31.5MPa, and adopts the CANopen bus digital communication interface. The installation interface conforms to the ISO 6264 standard and is used to replace the original Rexroth DBE series proportional relief valve in the hydraulic system of the 45MN high-speed forging machine.

[0077] The multi-source status sensing module includes a pressure sensor, a differential pressure sensor, a voltage acquisition module, a current acquisition module, a displacement sensor, a temperature sensor, and a timing module, which are used to collect hydraulic system operating parameters in real time.

[0078] In this embodiment, the pressure sensor used is a Hydac HDA 4700-A-0400-000 model pressure sensor with a G1 / 4" threaded interface, a range of 0–40 MPa, an accuracy of ±0.25%FS, and an output signal of 4mA–20mA. It is installed on the P, A, B, and T ports of the digitally controlled integrated high-frequency response proportional servo valve. During installation, please note: (1) Before installing the sensor, check the cleanliness of the pressure tap to ensure that there are no metal shavings or impurities; (2) The sensor installation torque shall be in accordance with the manufacturer’s specifications (G1 / 4" interface torque 20 N·m). (3) The sensor signal line uses a shielded cable, and the shielding layer is grounded at one end; (4) The sensor is powered by 24VDC, which is provided by the PLC power supply module.

[0079] The differential pressure sensor is a Hydac HDA 4745-A-0005-000 model differential pressure sensor with a range of 0 to 5 MPa, an accuracy of ±0.5%FS, and an output signal of 4mA to 20mA. It is installed between the P port and the A port, and between the P port and the B port of the digitally controlled integrated high-frequency response proportional servo valve. Both the voltage and current acquisition modules use Siemens SM 1231 analog input modules with 16-bit resolution and a sampling period of ≤10ms, capable of simultaneously acquiring 8 channels of analog signals. The voltage acquisition module is used to acquire the main valve command voltage signal (±10V), main valve feedback voltage signal (±10V), pilot valve command voltage signal (±10V), and pilot valve feedback voltage signal (±10V) of the digitally controlled integrated high-frequency response proportional servo valve; the current acquisition module is used to acquire the coil drive current signal (0-2.5A) of the digitally controlled integrated high-frequency response proportional servo valve. The displacement sensor is a Balluff BTL5-E10-M0100-P-S32 magnetostrictive displacement sensor with a range of 0-100mm, an accuracy of ±0.01mm, and an output signal of 4mA-20mA. It is installed on the valve core position detection end of the digitally controlled integrated high-frequency response proportional servo valve to monitor the opening degree of the main valve core in real time.

[0080] The temperature sensor is a Hydac ETS 3800-100-000 model, with a range of -25℃ to 100℃, an accuracy of ±0.5℃, and an output signal of 4mA to 20mA. It is installed on the valve body surface of the digitally controlled integrated high-frequency response proportional servo valve for real-time monitoring of the valve assembly's operating temperature. The timing module is integrated into the PLC control unit and is used to count the cumulative operating time of the valve assembly.

[0081] After installing the above sensors, each sensor needs to be debugged. The debugging process is as follows: (1) Check that all sensors are securely installed and that the wiring is correct; (2) Power on the sensor and check that the output signal is within the range; (3) Configure the analog input channel in the PLC and set the range conversion parameters; (4) Perform zero-point calibration and full-scale calibration; (5) Conduct dynamic response tests to check the sampling period and filtering effect.

[0082] The PLC control unit uses a Siemens S7-1200 series PLC with a CPU model of CPU 1214C DC / DC / DC. It integrates 14 digital inputs, 10 digital outputs, 2 analog inputs, and 2 analog outputs. It also integrates a Profinet communication interface to receive signals collected by the multi-source status sensing module, complete data processing, and interact with the host computer.

[0083] The PLC program adopts a modular design, including the main program (OB1), data acquisition program (FC1), data filtering program (FC2), threshold judgment program (FC3), trend judgment program (FC4), deviation judgment program (FC5), alarm output program (FC6), and communication program (FC7).

[0084] Data Acquisition Program (FC1) Functions: (1) Read the analog input values ​​of each sensor and convert them into engineering units (MPa, ℃, mm, etc.). (2) Read the CANopen communication data of the digitally controlled integrated high-frequency response proportional servo valve, including the main valve command signal, the main valve feedback signal, the pilot valve command signal, and the pilot valve feedback signal; (3) Calculate the main valve command deviation and the pilot valve command deviation; (4) Statistical valve group cumulative working time.

[0085] Data filtering program (FC2) functions: A first-order inertial filtering algorithm is used, with filtering coefficient α = 0.2, and the filtering formula is as follows: Y(n) = α × X(n) + (1-α) × Y(n-1) Where X(n) is the current sampled value, Y(n) is the current filtered output value, and Y(n-1) is the filtered output value at the previous time step.

[0086] Threshold determination program (FC3) functions: (1) Valve inlet pressure threshold judgment: IF P port pressure > 35MPa THEN triggers high pressure alarm; IF P port pressure < 0.5MPa THEN triggers low pressure alarm; (2) Valve downstream pressure threshold judgment: IF A port pressure > 31.5MPa OR B port pressure > 31.5MPa THEN trigger high pressure alarm; (3) Differential pressure threshold judgment: IF PA port differential pressure > 5MPa OR PB port differential pressure > 5MPa THEN trigger differential pressure alarm; (4) Voltage threshold judgment: IF |Main valve command voltage - main valve feedback voltage| > 0.5V THEN trigger voltage abnormality alarm; (5) Current threshold judgment: IF coil drive current < 0.1A OR coil drive current > 2.5A THEN trigger current abnormality alarm; (6) Temperature threshold judgment: IF valve body temperature > 80℃ THEN trigger high temperature alarm.

[0087] Trend Analysis Program (FC4) Functionality: (1) Pressure change rate judgment: Calculate the pressure change value ΔP within 1 minute. If ΔP>5MPa, trigger the pressure change alarm. (2) Temperature change rate judgment: Calculate the temperature change value ΔT within 10 minutes. If ΔT>10℃, then trigger the temperature change alarm.

[0088] Deviation detection program (FC5) functions: (1) Judgment of main valve command deviation: IF |main valve command voltage - main valve feedback voltage|>0.3V THEN Trigger main valve tracking abnormal alarm; (2) Pilot valve command deviation judgment: IF |pilot valve command voltage - pilot valve feedback voltage|>0.2V THEN trigger pilot valve tracking abnormal alarm.

[0089] Alarm Output Program (FC6) Functions: (1) Output alarm signals according to the alarm level: Level 1 warning (yellow indicator light), Level 2 warning (orange indicator light), Level 3 alarm (red indicator light and buzzer); (2) Record the alarm time, alarm type, and alarm parameter values; (3) Send the alarm information to the host computer via the Profinet bus.

[0090] Communication program (FC7) functions: (1) Data interaction with the host computer is performed via the Profinet bus, with a transmission cycle of 100ms; (2) Communicate with the digitally controlled integrated high-frequency response proportional servo valve via CANopen bus, with a transmission cycle of 10ms; (3) Data packaging format: Device number (2 bytes) + Parameter type (2 bytes) + Parameter value (4-byte floating-point number) + Timestamp (4 bytes).

[0091] The host computer is an industrial control computer with the following configuration: CPU Intel Core i5-10400, memory 16GB, hard drive 512GB SSD, operating system Windows 10 IoT Enterprise.

[0092] The host computer visualization platform is developed using Siemens WinCC V7.5 configuration software and communicates with the PLC control unit via the Profinet bus. The platform is used to dynamically visualize the hydraulic system's operating status, including a dynamic display area for the hydraulic system schematic diagram, a real-time data bar, valve status indicator lights, a historical trend curve window, an alarm pop-up notification area, and a health and maintenance statistics area. The dynamic display area for the hydraulic system schematic diagram uses vector graphics to draw the schematic diagram of the 45MN high-speed forging machine's hydraulic system, including the main pump group (6 main pumps), the proportional control unit's reconfigurable hydraulic control valve group (3 groups), the main hydraulic cylinders (3), the filling valves (3), the accumulators (2), the cooler (1), and the oil tank (1). Each component is represented by a standard hydraulic symbol, and pipelines are represented by solid lines (high-pressure pipelines) or dashed lines (return oil pipelines). The component color changes with its status: green for normal operation, red for fault shutdown, yellow for warning status, purple for debugging status, blue for standby status, cyan for maintenance status, and gray for offline status. Clicking on a component will bring up a detailed parameter window, displaying the component's real-time data and historical trends.

[0093] Real-time data section: (1) Place real-time data labels next to each component in the schematic diagram to display key parameters; (2) Display next to the proportional servo valve: P port pressure, A port pressure, B port pressure, main valve command voltage, main valve feedback voltage, valve core opening degree, valve body temperature; (3) Display near the main pump: pump outlet pressure, pump operating status, and pump cumulative operating time; (4) Display next to the hydraulic cylinder: pressure in the upper chamber of the cylinder, pressure in the lower chamber of the cylinder, and position of the slider.

[0094] Valve status indicator area: (1) Arrange a seven-color status indicator light next to the hydraulic control valve group reconfigured by the proportional control unit; (2) Indicator light color definition: green - normal operation, red - fault shutdown, yellow - warning status, purple - debugging status, blue - standby status, cyan - maintenance status, gray - offline status; (3) Indicator light flashing frequency: always on during normal operation, flashing at 1Hz during warning mode, and flashing at 2Hz during alarm mode.

[0095] Historical trend curve window: (1) Supports displaying up to 8 historical trend curves simultaneously; (2) The time span can be selected as: 1 minute, 5 minutes, 15 minutes, 30 minutes, 1 hour, 4 hours, 8 hours, 24 hours; (3) Curve types include: pressure curve (red), temperature curve (blue), voltage curve (green), current curve (yellow), and displacement curve (purple); (4) Supports curve scaling, translation, data point query and export functions.

[0096] Alarm pop-up notification area: (1) When the system triggers an alarm, an alarm prompt window will automatically pop up; (2) The alarm window displays: alarm time, alarm level, alarm type, alarm parameter value, and alarm description; (3) Provide "Confirm", "Mute", "View Details" and "Processing Guide" buttons; (4) Unconfirmed alarms continue to be displayed, while confirmed alarms are moved to the historical alarm list.

[0097] Health and Operations Statistics Area: (1) Valve group health assessment: The health index (0-100%) is calculated based on the cumulative working time, number of failures, and degree of parameter drift. (2) Maintenance reminders: Maintenance reminders are automatically generated based on the cumulative working hours and the manufacturer's recommended maintenance cycle; (3) Fault statistics: Statistics on fault types, number of faults, and average processing time by month / quarter / year; (4) Spare parts inventory: Displays the inventory quantity of key spare parts and the warning line.

[0098] The fault diagnosis and rapid processing module is developed in C#, runs on the host computer, and uses SQL Server 2019 Express as the database.

[0099] See Figure 4 The fault diagnosis and rapid handling module has a built-in fault tree analysis model and expert rule base. The fault tree analysis (FTA) model construction process is as follows: The system fault is the top event, with proportional valve fault, cartridge valve fault, relief valve fault, sensor fault, and oil fault as intermediate events, and proportional valve coil open circuit, proportional valve coil short circuit, proportional valve spool sticking, proportional valve internal leakage, and proportional valve aging and wear as the top event. The following are considered as base events: wear, spool sticking (CV_Spool_Stuck), internal leakage (CV_Internal_Leak), pressure regulation failure (RV_Pressure_Failure), pressure sensor failure (PS_Fault), displacement sensor failure (DS_Fault), differential pressure sensor failure (DPS_Fault), oil contamination (Oil_Contamination), and oil temperature overheating (Oil_Temp_High). Logical relationships are constructed using logic gates, including OR and AND gates. OR means that the occurrence of any base event leads to the upper-level event, while AND means that the occurrence of all base events simultaneously leads to the upper-level event.

[0100] The expert rule base is stored in an SQL Server database, with the following table structure: Rule table (main rule table):

[0101] The expert rule inventory mainly includes the following diagnostic rules: Rule 1: When the main valve command deviation is > ±0.3V and the coil drive current is <0.1A, the diagnosis result is that the proportional valve coil is open-circuited. The handling steps are to check the coil wiring, measure the coil resistance, and replace the coil or valve. The spare parts list is 1 proportional servo valve coil, level: 3 (alarm). Rule 2: When the main valve command deviation is > ±0.3V and the coil drive current is > 2.5A, the diagnosis result is a short circuit in the proportional valve coil. The handling steps are to check the coil insulation, measure the coil resistance, and replace the coil or valve. The spare parts list is 1 proportional servo valve coil. Rule 3: When the P port pressure of the digitally controlled integrated high-frequency response proportional servo valve is >35MPa and the A port pressure is <5MPa, the diagnosis result is that the proportional valve main valve core is stuck. The handling steps are to check the cleanliness of the oil, disassemble and inspect the valve core, clean or replace the valve core, and the spare parts list is proportional servo valve core ×1, level: 3 (alarm). Rule 4: When the differential pressure at the PA port of the digitally controlled integrated high-frequency response proportional servo valve is <0.5MPa and the main valve core opening is >50%, the diagnosis result is severe internal leakage of the proportional valve. The handling steps are to check the valve core wear, check the seals, and replace the seals or valve components. The spare parts list is 1 proportional servo valve sealing kit. Level: 2 (Warning). Rule 5: When the valve body temperature is >80℃ and the temperature change rate is >1℃ / min, the diagnosis result is abnormal valve group temperature rise. The handling steps are to check the cooling system, check the oil viscosity, reduce the working frequency, and the spare parts list is cooler filter element ×1. Level: 2 (warning). Rule 6: When the pressure sensor output is <4mA or >20mA, the diagnosis result is a pressure sensor failure. The handling steps are to check the sensor wiring, check the sensor power supply, and replace the sensor. The spare parts list is 1 pressure sensor. Level: 3 (alarm). Rule 7: When the displacement sensor outputs <4mA or >20mA, the diagnosis result is a displacement sensor failure. The handling steps are to check the sensor wiring, check the magnetic ring position, and replace the sensor. The spare parts list is 1 displacement sensor. Rule 8: When the differential pressure sensor outputs <4mA or >20mA, the diagnosis result is a differential pressure sensor failure. The troubleshooting steps are to check the sensor wiring, check for blockages at the pressure tap, and replace the sensor. The spare parts list is 1 differential pressure sensor. Rule 9: When the pressure before the valve is <0.5MPa and the main pump is running, the diagnosis result is insufficient oil supply pressure. The handling steps are to check the main pump suction port, check for filter blockage, check for internal leakage of the pump, and the spare parts list is 1 main pump seal. Rule 10: When the cumulative working time is >8760h and the valve core opening response time is >15ms, the diagnosis result is proportional valve aging and wear. The handling steps are to assess valve core wear, replace the valve core or the whole valve, and recalibrate. The spare parts list is proportional servo valve ×1, level: 1 (hint).

[0102] See Figure 5The fault diagnosis and rapid processing module's diagnostic process includes real-time acquisition of multi-source status data, data filtering and threshold judgment, anomaly identification and graded early warning, fault tree (FTA) inference, expert rule base matching, precise fault location, output of processing solutions and steps, on-site execution and parameter verification, fault closure and record archiving, and pushing processing steps and spare parts lists to the operation terminal. The specific process is as follows: (1) Real-time data reading: Read sensor data and valve status data from PLC via Profinet bus; (2) Rule matching: Match real-time data with each rule in the rule base; (3) Fault location: When the conditions of a certain rule are met, the diagnostic result corresponding to that rule is output; (4) Handling multiple rule conflicts: When multiple rules are satisfied at the same time, priority is given to the severity level (alarm > warning > prompt), and for the same level, priority is given to the rule number; (5) Processing solution output: push the diagnosis results, processing steps, spare parts list and acceptance criteria to the operation terminal; (6) Closed-loop recording: After the operator completes the processing, he / she confirms the processing result in the system and records the processing time and verification data.

[0103] The overall commissioning of the proportional control unit and fault diagnosis system of the hydraulic system of the high-speed forging mill was carried out. The specific process is as follows: (1) Hardware check: Check that all sensors, PLC, host computer and communication lines are installed correctly and the wiring is secure; (2) Individual debugging: Debug the proportional control unit to reconstruct the hydraulic control valve group, the multi-source status sensing module, the PLC control unit, the host computer visualization platform and the fault diagnosis and rapid processing module respectively; (3) System integration testing: Integrate and test each module to check data communication, signal transmission and linkage logic; (4) No-load operation: Run the hydraulic system under no-load conditions and check the operation of each valve, sensor readings and the display on the host computer; (5) Load testing: Perform 50%, 75% and 100% load tests to check system response and stability; (6) Continuous operation test: run continuously for 72 hours to check the system reliability and data acquisition integrity.

[0104] Example 6 A method for reconstructing and diagnosing faults in the proportional control unit of a high-speed forging mill hydraulic system includes the following steps: Step 1: Measure and map the original valve group in the hydraulic system of the high-speed forging machine to determine the installation dimensions, flow and pressure characteristics, and control signal type, and complete the equivalent selection of the digital proportional valve; Step 2: Reconstruct the hydraulic control valve group with the proportional control unit to directly replace the original valve group, optimize the valve block flow channel and damping parameters, and complete the no-load debugging, pressure holding test and continuous forging reliability verification. Step 3: The hydraulic system's operating pressure, differential pressure, voltage, current, displacement, and temperature signals are collected in real time through the multi-source status sensing module and transmitted to the PLC control unit. Step 4: The PLC control unit processes the received signals and uploads them to the host computer. The host computer's visualization platform then displays the hydraulic system's operating status. Step 5: When parameters are out of tolerance or the status is abnormal, the fault diagnosis and rapid processing module starts fault tree reasoning and expert rule matching to automatically identify hydraulic system faults and quickly locate the fault point. Step 6: The system outputs diagnostic conclusions, troubleshooting steps, and a spare parts list to guide operators in completing rapid handling and forming a closed-loop record.

[0105] The method for reconstructing and diagnosing the fault of the proportional control unit of the hydraulic system of the high-speed forging mill was verified. The verification process is as follows: (1) Proportional control unit reconfiguration rate: 100% (all three main hydraulic cylinder proportional control valves have been replaced with digital integrated valves). (2) Response time: The response time of the digital proportional valve is ≤10ms, which is better than the original analog valve's 15ms; (3) Control accuracy: Position control accuracy ±0.08mm, which is better than the original system's ±0.5mm; (4) Status monitoring parameters: 12 key parameters can be monitored in real time (4 pressure parameters, 2 differential pressure parameters, 4 voltage parameters, 1 current parameter, and 1 displacement parameter). (5) Fault location time: The average fault location time is 3.2 minutes, which is far better than the hourly time of the original system; (6) Equipment downtime: Unplanned downtime reduced by 35%; (7) Operation and maintenance costs: Spare parts procurement costs were reduced by 45%, the supply cycle was shortened by 57%, and the labor cost for fault handling was reduced by 60%.

Claims

1. A hydraulic system proportional control unit reconfiguration and fault diagnosis system for high-speed forging mills, characterized in that, The system includes a proportional control unit for reconstructing the hydraulic control valve group, a multi-source status sensing module, a PLC control unit, a host computer visualization platform, and a fault diagnosis and rapid processing module. The core of the proportional control unit for reconstructing the hydraulic control valve group is a digitally controlled integrated high-frequency response proportional servo valve, used to replace the proportional control valve of the main hydraulic cylinder in the original hydraulic system of the 45MN high-speed forging machine. The multi-source status sensing module is used to collect hydraulic system operating parameters in real time. The PLC control unit is used to receive signals collected by the multi-source status sensing module, complete data processing, and interact with the host computer. The host computer visualization platform is used to realize dynamic visualization of the hydraulic system operating status. The fault diagnosis and rapid processing module runs on the host computer to identify hydraulic system faults and output diagnostic conclusions and processing steps.

2. The hydraulic system proportional control unit reconfiguration and fault diagnosis system for high-speed forging mills according to claim 1, characterized in that, The reconfigured hydraulic control valve group of the proportional control unit includes a digitally controlled integrated high-frequency response proportional servo valve, a high-flow logic cartridge valve, a pilot-operated proportional relief valve, and a safety valve, which are completely equivalent to the original valve group installation interface, control signal, and pressure and flow parameters in the hydraulic system of the 45MN fast forging machine.

3. The hydraulic system proportional control unit reconfiguration and fault diagnosis system for high-speed forging mills according to claim 2, characterized in that, The digitally controlled integrated high-frequency response proportional servo valve has a rated working pressure of 35MPa, a rated flow rate of 400L / min, a response time ≤10ms, and a control accuracy of ±0.1%. It adopts a CANopen bus digital communication interface, and the control signal is a ±10V analog signal or a CANopen digital signal. The installation interface conforms to the ISO 4401-08 standard. The large-flow logic cartridge valve has a nominal diameter of NG63, a rated working pressure of 31.5MPa, a rated flow rate of 2000L / min, and a proportional pilot control method. The installation interface conforms to the ISO 7368 standard and is used to replace the cartridge valve in the original hydraulic system. The pilot-operated proportional relief valve has a rated working pressure of 31.5MPa, a pressure adjustment range of 0.5MPa~31.5MPa, adopts a CANopen bus digital communication interface, and the installation interface conforms to the ISO 6264 standard. It is used to replace the proportional relief valve in the original hydraulic system.

4. The hydraulic system proportional control unit reconfiguration and fault diagnosis system for high-speed forging mills according to claim 3, characterized in that, The multi-source state sensing module includes a pressure sensor, a differential pressure sensor, a voltage acquisition module, a current acquisition module, a displacement sensor, a temperature sensor, and a timing module. The pressure sensor has a range of 0–40 MPa, an accuracy of ±0.25%FS, and an output signal of 4mA–20mA. It is installed at ports P, A, B, and T of the digitally controlled integrated high-frequency response proportional servo valve. The differential pressure sensor has a range of 0–5 MPa, an accuracy of ±0.5%FS, and an output signal of 4mA–20mA. It is installed between ports P and A, and between ports P and B of the digitally controlled integrated high-frequency response proportional servo valve. The voltage acquisition module has a sampling period of ≤10ms and is used to acquire the main valve command voltage signal, the main valve feedback voltage signal, and the pilot valve voltage signal of the digitally controlled integrated high-frequency response proportional servo valve. The system includes a command voltage signal and a pilot valve feedback voltage signal. The sampling period of the current acquisition module is ≤10ms, used to acquire the coil drive current signal of the digitally controlled integrated high-frequency response proportional servo valve. The displacement sensor is a magnetostrictive displacement sensor with a range of 0~100mm, an accuracy of ±0.01mm, and an output signal of 4mA~20mA. It is installed on the valve core position detection end of the digitally controlled integrated high-frequency response proportional servo valve to monitor the main valve core opening degree in real time. The temperature sensor has a range of -25℃~100℃, an accuracy of ±0.5℃, and an output signal of 4mA~20mA. It is installed on the valve body surface of the digitally controlled integrated high-frequency response proportional servo valve to monitor the valve group's operating temperature in real time. The timing module is integrated into the PLC control unit to count the cumulative operating time of the valve group.

5. The hydraulic system proportional control unit reconfiguration and fault diagnosis system for high-speed forging mills according to claim 4, characterized in that, The CPU processor in the PLC control unit is a CPU 1214C DC / DC / DC, which integrates a Profinet communication interface. After receiving the signals collected by the multi-source status sensing module, the PLC control unit performs data filtering, logic judgment, and threshold alarm. The data filtering adopts a first-order inertial filtering algorithm with a filtering coefficient α=0.2 and a filtering formula Y(n)=α×X(n)+(1-α)×Y(n-1), where X(n) is the current sampled value, Y(n) is the current filtered output value, and Y(n-1) is the filtered output value at the previous moment. The logical judgment includes threshold judgment, trend judgment, and deviation judgment. Threshold judgment includes: triggering a high-pressure alarm when the P-port pressure of the digitally controlled integrated high-frequency response proportional servo valve is >35MPa; triggering a low-pressure alarm when the P-port pressure is <0.5MPa; triggering a high-pressure alarm when the A-port or B-port pressure of the digitally controlled integrated high-frequency response proportional servo valve is >31.5MPa; triggering a differential pressure alarm when the PA-port differential pressure is >5MPa or the PB-port differential pressure is >5MPa; triggering a voltage abnormality alarm when the main valve command voltage deviation is >±0.5V; and triggering a voltage abnormality alarm when... A current abnormality alarm is triggered when the coil drive current is <0.1A or >2.5A, and a high temperature alarm is triggered when the valve body temperature is >80℃. Trend judgment includes: a pressure change alarm is triggered when the pressure change within 1 minute is >5MPa, and a temperature change alarm is triggered when the temperature change within 10 minutes is >10℃. Deviation judgment includes: a main valve tracking abnormality alarm is triggered when the deviation between the main valve command voltage and the main valve feedback voltage is >±0.3V, and a pilot valve tracking abnormality alarm is triggered when the deviation between the pilot valve command voltage and the pilot valve feedback voltage is >±0.2V.

6. The hydraulic system proportional control unit reconfiguration and fault diagnosis system for high-speed forging mills according to claim 5, characterized in that, The host computer visualization platform runs on an industrial control computer and communicates with the PLC control unit via the Profinet bus. The host computer visualization platform includes a dynamic display area for the hydraulic system schematic diagram, a real-time data bar, a valve status indicator area, a historical trend curve window, an alarm pop-up prompt area, and a health and maintenance statistics area. The dynamic display area for the hydraulic system schematic diagram draws the hydraulic system schematic diagram of the 45MN high-speed forging machine in vector graphics, including the main pump group, the proportional control unit reconfigured hydraulic control valve group, the main hydraulic cylinder, the charging valve, the accumulator, the cooler, and the oil tank. The valve status indicator area uses seven colors to indicate the working status of the valve group: green indicates normal operation, red indicates fault shutdown, yellow indicates warning status, purple indicates debugging status, blue indicates standby status, cyan indicates maintenance status, and gray indicates offline status.

7. The hydraulic system proportional control unit reconfiguration and fault diagnosis system for high-speed forging mills according to claim 6, characterized in that, The fault diagnosis and rapid processing module incorporates a fault tree analysis model and an expert rule base. The fault tree analysis model uses system faults as the top event, proportional valve faults, cartridge valve faults, relief valve faults, sensor faults, and oil faults as intermediate events, and specific fault modes as bottom events to construct logical relationships. The expert rule base contains the following diagnostic rules: Rule 1: When the main valve command deviation is > ±0.3V and the coil drive current is <0.1A, the diagnosis result is that the proportional valve coil is open-circuited. The handling steps are to check the coil wiring, measure the coil resistance, and replace the coil or valve. The spare parts list is 1 proportional servo valve coil. Rule 2: When the main valve command deviation is > ±0.3V and the coil drive current is > 2.5A, the diagnosis result is a short circuit in the proportional valve coil. The handling steps are to check the coil insulation, measure the coil resistance, and replace the coil or valve. The spare parts list is 1 proportional servo valve coil. Rule 3: When the pressure at port P of the digitally controlled integrated high-frequency response proportional servo valve is >35MPa and the pressure at port A is <5MPa, the diagnosis result is that the main valve core of the proportional valve is stuck. The handling steps are to check the cleanliness of the oil, disassemble and inspect the valve core, clean or replace the valve core, and the spare parts list is proportional servo valve core ×1. Rule 4: When the differential pressure at the PA port of the digitally controlled integrated high-frequency response proportional servo valve is <0.5MPa and the main valve core opening is >50%, the diagnosis result is that the proportional valve has serious internal leakage. The handling steps are to check the valve core wear, check the seals, and replace the seals or valve parts. The spare parts list is 1 proportional servo valve sealing kit. Rule 5: When the valve body temperature is >80℃ and the temperature change rate is >1℃ / min, the diagnosis result is abnormal valve group temperature rise. The handling steps are to check the cooling system, check the oil viscosity, reduce the working frequency, and the spare parts list is cooler filter element ×1. Rule 6: When the pressure sensor outputs <4mA or >20mA, the diagnosis is a pressure sensor failure. The troubleshooting steps are to check the sensor wiring, check the sensor power supply, and replace the sensor. The spare parts list is 1 pressure sensor. Rule 7: When the displacement sensor outputs <4mA or >20mA, the diagnosis result is a displacement sensor failure. The handling steps are to check the sensor wiring, check the magnetic ring position, and replace the sensor. The spare parts list is 1 displacement sensor. Rule 8: When the differential pressure sensor outputs <4mA or >20mA, the diagnosis result is a differential pressure sensor failure. The troubleshooting steps are to check the sensor wiring, check for blockages at the pressure tap, and replace the sensor. The spare parts list is 1 differential pressure sensor. Rule 9: When the pressure before the valve is <0.5MPa and the main pump is running, the diagnosis result is insufficient oil supply pressure. The handling steps are to check the main pump suction port, check for filter blockage, check for internal leakage of the pump, and the spare parts list is 1 main pump seal. Rule 10: When the cumulative working time is >8760h and the valve core opening response time is >15ms, the diagnosis result is that the proportional valve is aging and worn. The handling steps are to assess the valve core wear, replace the valve core or the whole valve, and recalibrate. The spare parts list is 1 proportional servo valve.

8. The hydraulic system proportional control unit reconfiguration and fault diagnosis system for high-speed forging mills according to claim 7, characterized in that, The diagnostic process of the fault diagnosis and rapid processing module includes real-time acquisition of multi-source status data, data filtering and threshold judgment, anomaly identification and hierarchical early warning, fault tree FTA reasoning, expert rule base matching, precise fault point location, output of processing solutions and steps, on-site execution and parameter verification, fault closure and record archiving, and pushing of processing steps and spare parts list to the operation terminal.

9. The hydraulic system proportional control unit reconfiguration and fault diagnosis system for high-speed forging mills according to claim 7, characterized in that, The host computer visualization platform supports historical curve playback, data report generation, and alarm pop-up notifications.

10. The method for reconstructing and diagnosing the fault of the proportional control unit of the hydraulic system of a high-speed forging mill as described in any one of claims 1-9, characterized in that, Includes the following steps: Step 1: Measure and map the original valve group in the hydraulic system of the 45MN high-speed forging machine to determine the installation dimensions, flow and pressure characteristics, and control signal type, and complete the equivalent selection of the digital proportional valve; Step 2: Reconstruct the hydraulic control valve group with the proportional control unit to directly replace the original valve group, optimize the valve block flow channel and damping parameters, and complete the no-load debugging, pressure holding test and continuous forging reliability verification. Step 3: The hydraulic system's operating pressure, differential pressure, voltage, current, displacement, and temperature signals are collected in real time through the multi-source status sensing module and transmitted to the PLC control unit. Step 4: The PLC control unit processes the received signals and uploads them to the host computer. The host computer's visualization platform then displays the hydraulic system's operating status. Step 5: When parameters are out of tolerance or the status is abnormal, the fault diagnosis and rapid processing module starts fault tree reasoning and expert rule matching to automatically identify hydraulic system faults and quickly locate the fault point. Step 6: The system outputs diagnostic conclusions, troubleshooting steps, and a spare parts list to guide operators in completing rapid handling and forming a closed-loop record.

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