Coal mill oil way plate and reversing control device thereof

Abstract

The invention provides a coal mill oil way plate and a reversing control device thereof, and relates to the technical field of coal mill oil way plates, the coal mill oil way plate comprises a valve block body, a proportional overflow valve, a duplex electromagnetic reversing valve group, a working oil way group, two hydraulic control one-way valve groups, two energy accumulators, a safety overflow valve, an online particle counter and a spiral cooling flow channel. The redundancy design of the duplex electromagnetic directional valve group improves the reliability of the system, so that the system can still be operated when a single valve fails, the hydraulic control one-way valve group realizes mechanical locking of an oil cylinder and can prevent a grinding roller from falling off during power failure, and the energy accumulator is connected with a working oil duct through a connector to absorb pressure impact and compensate leakage, so that the stability of loading pressure is maintained, and the reliability of the system is improved. The on-line particle counter gives an early warning of oil pollution in real time, hydraulic faults can be reduced, the spiral cooling flow channel is matched with the semiconductor temperature control piece to adjust the oil temperature, and the problem of pressure drift caused by oil viscosity fluctuation under high and low temperature working conditions is solved.

Description

Technical Field

[0001] This invention belongs to the technical field of coal mill oil circuit board, specifically relating to a coal mill oil circuit board and its reversing control device. Background Technology

[0002] In the field of coal mill oil circuit board and reversing control device technology, the existing coal mill oil circuit system has many technical bottlenecks; Traditional hydraulic circuit boards mostly use a single solenoid valve control architecture. When the solenoid valve jams or malfunctions, it can easily lead to the paralysis of the entire hydraulic system, resulting in insufficient system reliability and an inability to meet the requirements of continuous operation. Existing devices lack an effective mechanical locking structure for the cylinders. In the event of a power outage or system depressurization, the grinding rollers may fall due to their own weight, posing a serious safety hazard. The connection between the accumulator and the working oil passage is mostly a direct connection without flow control elements, resulting in significant system pressure fluctuations during the charging and discharging of the accumulator, making it difficult to maintain a stable loading pressure. In terms of oil contamination monitoring, traditional systems mostly rely on periodic offline detection, which cannot monitor the number and size of contaminant particles in the oil in real time, making it difficult to provide timely warnings of hydraulic component wear or jamming failures caused by oil contamination. In addition, the temperature control methods of existing hydraulic circuit boards are relatively crude, usually only using simple coolers or heaters, which cannot be adjusted accurately in real time according to the oil temperature. Under high and low temperature conditions, fluctuations in oil viscosity can cause pressure drift, affecting the loading accuracy and stability of the coal mill. Summary of the Invention

[0003] The present invention provides a coal mill oil circuit board and its reversing control device to solve at least one of the technical problems mentioned above.

[0004] To solve the above-mentioned technical problems, the present invention discloses a coal mill hydraulic circuit board and its reversing control device, the hydraulic circuit board comprising: The valve block body has interconnected main pressure oil passage P, return oil passage T, working oil passage A1, working oil passage B1, working oil passage A2 and working oil passage B2. The proportional relief valve is integrated into the main pressure oil passage P inlet of the valve block body and is used to set the loading pressure; The dual solenoid directional valve assembly includes valves 3.1 and 3.2, which are connected in parallel downstream of the proportional relief valve. Both valves 3.1 and 3.2 contain two three-position four-way solenoid valves. The working oil passage assembly, including working oil passage A1, working oil passage B1, working oil passage A2 and working oil passage B2, is used to communicate with valves 3.1 and 3.2; Two sets of hydraulically controlled check valve groups, each group containing two hydraulically controlled check valves. The first set of hydraulically controlled check valves includes hydraulically controlled check valve 4.1A and hydraulically controlled check valve 4.1B, and the second set of hydraulically controlled check valves includes hydraulically controlled check valve 4.2A and hydraulically controlled check valve 4.2B. Hydraulically controlled check valves 4.1A, 4.1B, 4.2A, and 4.2B are used to connect the double solenoid directional valve group and the working oil passage group. Two accumulators, including accumulator one and accumulator two, are connected to working oil passage A1 and working oil passage A2 respectively through accumulator interface 5.1 and accumulator interface 5.2; The safety relief valve has its inlet connected to the main pressure oil passage P and its outlet connected to the return oil passage T. An online particle counter, embedded in the inlet of the return oil passage T, is used to detect in real time the number of contaminant particles with a particle size larger than a preset particle size in the oil in the return oil passage T. A spiral cooling channel is located inside the valve block body. A semiconductor temperature control chip is integrated on the outer wall of the spiral cooling channel. The inlet and outlet of the spiral cooling channel are connected to the external coolant circulation system, respectively.

[0005] Preferably, the P port of valves 3.1 and 3.2 is connected to the main pressure oil passage P, the T port of valves 3.1 and 3.2 is connected to the return oil passage T, the A port of valve 3.1 and the B port of valve 3.2 are respectively used to connect to the working oil passage A1 and the working oil passage B1, and the A port of valve 3.2 and the B port of valve 3.2 are respectively used to connect to the working oil passage A2 and the working oil passage B2.

[0006] Preferably, one end of the hydraulic control check valve 4.1A and hydraulic control check valve 4.1B is connected to port A and port B of valve 3.1, respectively, and the other end of the hydraulic control check valve 4.1A and hydraulic control check valve 4.1B is connected to working oil passage A1 and working oil passage B1, respectively. One end of the hydraulic control check valve 4.2A and hydraulic control check valve 4.2B is connected to port A and port B of valve 3.2, respectively, and the other end of the hydraulic control check valve 4.2A and hydraulic control check valve 4.2B is connected to working oil passage A2 and working oil passage B2, respectively. Among them, the pilot control ports of hydraulic check valve 4.1A and hydraulic check valve 4.2A are connected to the main pressure oil passage P through independent oil circuits.

[0007] Preferably, a one-way throttle valve one and a one-way throttle valve two are respectively provided between the accumulator interface 5.1 and the accumulator interface 5.2 and the working oil passage A1 and the working oil passage A2. The one-way throttle valves are used to control the charging and discharging speed of the accumulator one and the accumulator two.

[0008] A commutation control device, comprising: The instruction input module is used to receive external input loading instruction signals and roller lifting instruction signals; The logic control module is connected to the output of the instruction input module. It is used to generate a reversing control signal based on the loading instruction signal or the roller lifting instruction signal, and to execute the interlock logic between the loading action and the roller lifting action, preventing the two instructions from taking effect at the same time. The execution drive module is connected to the output of the logic control module and is used to drive the operation of valves 3.1 and 3.2 in the double electromagnetic directional valve group in the coal mill oil circuit board. The locking safety module is used to control the mechanical locking and releasing of the hydraulic cylinder by monitoring the pilot control port pressure status of the hydraulic control check valves 4.1A and 4.2A in the coal mill oil circuit board.

[0009] Preferably, the logic control module includes an action interlock submodule and a redundancy check submodule; The action interlock submodule is used to automatically block the roller lifting command signal when the loading command signal is detected to be activated, and to automatically block the loading command signal when the roller lifting command signal is detected to be activated. The redundancy verification submodule is used to receive the position sensor signals of valve 3.1 and valve 3.2 in real time. When the valve position deviation of valve 3.1 and valve 3.2 exceeds 10% of the stroke, it sends a stop command to the execution drive module.

[0010] Preferably, the locking safety module includes a pilot pressure monitoring submodule and an emergency locking submodule; The pilot pressure monitoring submodule is used to detect the oil pressure value of the pilot control port of the hydraulic check valve 4.1A and the pilot control port of the hydraulic check valve 4.2A in real time. When the pressure value is lower than 5MPa, a low pressure alarm is triggered. The emergency locking submodule is used to forcibly close the oil passages of hydraulic check valves 4.1A, 4.1B, 4.2A, and 4.2B when the pressure value of the main pressure oil passage P of the system is lower than 8MPa.

[0011] Preferably, it also includes a pressure control module and a status monitoring module. The pressure control module includes a pressure closed-loop submodule and a ramp control submodule. The status monitoring module includes a pressure sensor group and a valve position feedback unit. The pressure closed-loop submodule is used to receive the real-time load sensor signal of the coal mill and dynamically adjust the current control signal of the proportional relief valve so that the pressure value of the working oil passage A1 is maintained within the range of ±0.5MPa. The ramp control submodule is used to control the pressure setpoint of the proportional relief valve to increase linearly to the target pressure value at a rate not exceeding 2 MPa per second after the loading command is activated. The pressure sensor group includes a first pressure sensor, a second pressure sensor and a third pressure sensor. The first pressure sensor is installed on the main pressure oil passage P, the second pressure sensor is installed on the working oil passage A1, and the third pressure sensor is installed on the working oil passage A2. The valve position feedback unit includes a first displacement sensor and a second displacement sensor. The first displacement sensor is used to detect the actual position of the valve core of valve 3.1, and the second displacement sensor is used to detect the actual position of the valve core of valve 3.2.

[0012] Preferably, it also includes a grinding roller wear condition prediction module, the grinding roller wear condition prediction module comprising: A high-frequency pressure sensor is installed on the working oil passage A1 of the coal mill oil circuit board to collect hydraulic pressure pulsation signals in real time. The spectrum analysis unit, electrically connected to the high-frequency pressure sensor, is used to perform a fast Fourier transform on the pressure signal and extract the amplitude components of a preset frequency range at each acquisition time. and corresponding frequencies ; The wear index calculation unit, electrically connected to the spectrum analysis unit, is used to calculate the real-time wear index based on the amplitude component An and the corresponding frequency fn extracted by the spectrum analysis unit. ;in, This is the real-time wear index. For the i-th acquisition time, the amplitude components of the preset frequency range are defined. The frequency corresponding to the preset frequency range at the i-th acquisition time, where K is the material coefficient of the grinding roller; The control execution unit is electrically connected to the wear index calculation unit. When the wear index exceeds the wear index set threshold, it reduces the loading pressure set value by 10% and triggers an audible and visual alarm.

[0013] Preferably, it also includes a valve core jamming treatment module, which includes: The current ripple detection unit is connected to the output terminal of the electromagnet drive circuit of valves 3.1 and 3.2, and is used to acquire the high-frequency ripple component of the operating current of valves 3.1 and 3.2 in real time. The hysteresis index calculator, electrically connected to the current ripple detection unit, is used to calculate the hysteresis index based on the high-frequency ripple component of the operating current of valves 3.1 and 3.2. A high-frequency oscillation injector is connected between the execution drive module and valves 3.1 and 3.2. It is used to superimpose a sinusoidal oscillation current with a frequency of 80Hz±5Hz and an amplitude of 20% of the rated drive current onto the coil of valve 3.1 or valve 3.2 when the sticking index is greater than the preset value of the sticking index. An automatic cleaning trigger, electrically connected to a stickiness index calculator, is used to send a circulating cleaning command to the main controller of the hydraulic system when the stickiness index decrease rate is less than a preset percentage. The actions triggered by this command include closing the proportional relief valve, controlling valves 3.1 and 3.2 to reciprocate at a frequency of 1Hz, and starting the flushing pump to circulate hydraulic oil at a flow rate of 40L / min for 10 minutes.

[0014] Compared with the prior art, the present invention has the following beneficial effects: The redundant design of the dual electromagnetic directional valve assembly in this invention improves system reliability, allowing operation even in the event of a single valve failure. The hydraulically controlled check valve assembly achieves mechanical locking of the cylinder, preventing the grinding roller from falling during power outages. The accumulator, connected to the working oil passage via an interface, can absorb pressure shocks and compensate for leaks, thereby maintaining stable loading pressure. The online particle counter provides real-time warnings of oil contamination, reducing hydraulic failures. The spiral cooling channel, combined with a semiconductor temperature control chip, can regulate oil temperature, resolving pressure drift caused by oil viscosity fluctuations under high and low temperature conditions. Attached Figure Description

[0015] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic diagram of the oil circuit board for the coal mill of the present invention. Figure 1 ; Figure 2 This is a schematic diagram of the oil circuit board for the coal mill of the present invention. Figure 2 . Detailed Implementation

[0016] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0017] Furthermore, in this invention, the use of terms such as "first" and "second" is for descriptive purposes only and does not specifically refer to any order or sequence, nor is it intended to limit the invention. They are merely used to distinguish components or operations described using the same technical terms and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions and features of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If a combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0018] The present invention provides the following embodiments. Example 1 This invention provides a coal mill hydraulic circuit board and its reversing control device, such as... Figure 1-2 As shown, it includes: The valve block body has interconnected main pressure oil passage P, return oil passage T, working oil passage A1, working oil passage B1, working oil passage A2 and working oil passage B2. The proportional relief valve is integrated into the main pressure oil passage P inlet of the valve block body and is used to set the loading pressure; The dual solenoid directional valve assembly includes valves 3.1 and 3.2, which are connected in parallel downstream of the proportional relief valve. Both valves 3.1 and 3.2 contain two three-position four-way solenoid valves. The working oil passage assembly, including working oil passage A1, working oil passage B1, working oil passage A2 and working oil passage B2, is used to communicate with valves 3.1 and 3.2; Two sets of hydraulically controlled check valve groups, each group containing two hydraulically controlled check valves. The first set of hydraulically controlled check valves includes hydraulically controlled check valve 4.1A and hydraulically controlled check valve 4.1B, and the second set of hydraulically controlled check valves includes hydraulically controlled check valve 4.2A and hydraulically controlled check valve 4.2B. Hydraulically controlled check valves 4.1A, 4.1B, 4.2A, and 4.2B are used to connect the double solenoid directional valve group and the working oil passage group. Two accumulators, including accumulator one and accumulator two, are connected to working oil passage A1 and working oil passage A2 respectively through accumulator interface 5.1 and accumulator interface 5.2; The safety relief valve has its inlet connected to the main pressure oil passage P and its outlet connected to the return oil passage T. An online particle counter, embedded in the inlet of the return oil passage T, is used to detect in real time the number of contaminant particles with a particle size larger than a preset particle size in the oil in the return oil passage T. A spiral cooling channel is located inside the valve block body. A semiconductor temperature control chip is integrated on the outer wall of the spiral cooling channel. The inlet and outlet of the spiral cooling channel are connected to the external coolant circulation system, respectively.

[0019] The working principle and beneficial effects of the above technical solution are as follows: The valve block body is machined with interconnected main pressure oil passage P, return oil passage T, working oil passage A1, working oil passage B1, working oil passage A2, and working oil passage B2. A proportional relief valve is integrated into the inlet of the main pressure oil passage P to set the loading pressure. The double-cell solenoid directional valve group includes valves 3.1 and 3.2, which are connected in parallel downstream of the proportional relief valve. Both valves 3.1 and 3.2 contain two three-position four-way solenoid valves. The working oil passage group is used to communicate with valves 3.1 and 3.2. The first group of the two sets of hydraulically controlled check valves includes a hydraulically controlled check valve 4.1. A and 4.1B, the second group includes hydraulically controlled check valves 4.2A and 4.2B to connect the double electromagnetic directional valve group and the working oil passage group. The two accumulators are connected to the working oil passages A1 and A2 respectively through accumulator interfaces 5.1 and 5.2. The inlet of the safety relief valve is connected to the main pressure oil passage P and the outlet is connected to the return oil passage T. An online particle counter is embedded in the inlet of the return oil passage T to detect the number of contaminant particles with a particle size larger than the preset particle size in the oil in real time. The spiral cooling channel is set inside the valve block body and the outer wall integrates a semiconductor temperature control chip. Its inlet and outlet are connected to the external coolant circulation system respectively. The redundant design of the dual electromagnetic directional valve assembly improves system reliability, allowing operation even in the event of a single valve failure. The hydraulically controlled check valve assembly achieves mechanical locking of the cylinder, preventing the grinding roller from falling during power outages. The accumulator, connected to the working oil passage via an interface, can absorb pressure shocks and compensate for leaks, thereby maintaining stable loading pressure. The online particle counter provides real-time warnings of oil contamination, reducing hydraulic failures. The spiral cooling channel, combined with a semiconductor temperature control chip, can regulate oil temperature, resolving pressure drift caused by oil viscosity fluctuations under high and low temperature conditions.

[0020] Example 2 Based on Example 1, the P ports of valves 3.1 and 3.2 are connected to the main pressure oil passage P, the T ports of valves 3.1 and 3.2 are connected to the return oil passage T, the A ports of valve 3.1 and 3.2 are used to connect to the working oil passage A1 and working oil passage B1 respectively, and the A ports of valve 3.2 and 3.2 are used to connect to the working oil passage A2 and working oil passage B2 respectively.

[0021] The working principle and beneficial effects of the above technical solution are as follows: 3.1 The P port of the valve is connected to the main pressure oil passage P, the T port is connected to the return oil passage T, and the A port and B port are respectively connected to the working oil passage A1 and the working oil passage B1. 3.2 The P port of the valve is connected to the main pressure oil passage P, the T port is connected to the return oil passage T, and the A port and B port are respectively connected to the working oil passage A2 and the working oil passage B2, forming an oil circuit architecture for independently controlling the dual grinding rollers. The direct-connection oil passage design reduces pressure loss; the independent dual-valve control allows the other roller to operate normally while one roller is under maintenance, reducing downtime.

[0022] Example 3 Based on Example 1, one end of the hydraulic control check valve 4.1A and hydraulic control check valve 4.1B is connected to port A and port B of valve 3.1, respectively, and the other end of the hydraulic control check valve 4.1A and hydraulic control check valve 4.1B is connected to working oil passage A1 and working oil passage B1, respectively. One end of the hydraulic control check valve 4.2A and hydraulic control check valve 4.2B is connected to port A and port B of valve 3.2, respectively, and the other end of the hydraulic control check valve 4.2A and hydraulic control check valve 4.2B is connected to working oil passage A2 and working oil passage B2, respectively. Among them, the pilot control ports of hydraulic check valve 4.1A and hydraulic check valve 4.2A are connected to the main pressure oil passage P through independent oil circuits.

[0023] The working principle and beneficial effects of the above technical solution are as follows: one end of the hydraulic check valves 4.1A and 4.1B is connected to port A and port B of valve 3.1 respectively, and the other end is connected to working oil passage A1 and working oil passage B1 respectively; one end of the hydraulic check valves 4.2A and 4.2B is connected to port A and port B of valve 3.2 respectively, and the other end is connected to working oil passage A2 and working oil passage B2 respectively; and the pilot control port of the hydraulic check valves 4.1A and 4.2A is connected to the main pressure oil passage P through an independent oil circuit. The pilot oil circuit has an independent oil supply to ensure that the hydraulic control check valve can be reliably opened under low pressure conditions; the series layout blocks reverse leakage of the oil cylinder and has a good pressure holding effect; the main pressure oil circuit P uses the system's high pressure to drive the pilot valve, eliminating the need for an additional oil source control.

[0024] Example 4 Based on Example 1, one-way throttle valve 1 and one-way throttle valve 2 are respectively provided between the accumulator interface 5.1 and accumulator interface 5.2 and the working oil passage A1 and working oil passage A2. The one-way throttle valve is used to control the charging and discharging speed of accumulator 1 and accumulator 2.

[0025] The working principle and beneficial effects of the above technical solution: One-way throttle valves are respectively provided between the accumulator interfaces 5.1 and 5.2 and the working oil passages A1 and A2 to control the charging and discharging speeds of accumulator one and accumulator two. The oil filling throttling prevents the accumulator from being filled with oil instantly, which would cause a sudden drop in system pressure. The oil discharge rate limiting avoids the accumulator from depressurizing rapidly and causing pressure fluctuations, thus extending the life of the accumulator diaphragm.

[0026] Example 5 Based on any one of embodiments 1-4, a commutation control device includes: The instruction input module is used to receive external input loading instruction signals and roller lifting instruction signals; The logic control module is connected to the output of the instruction input module. It is used to generate a reversing control signal based on the loading instruction signal or the roller lifting instruction signal, and to execute the interlock logic between the loading action and the roller lifting action, preventing the two instructions from taking effect at the same time. The execution drive module is connected to the output of the logic control module and is used to drive the operation of valves 3.1 and 3.2 in the double electromagnetic directional valve group in the coal mill oil circuit board. The locking safety module is used to control the mechanical locking and releasing of the hydraulic cylinder by monitoring the pilot control port pressure status of the hydraulic control check valves 4.1A and 4.2A in the coal mill oil circuit board.

[0027] The working principle and beneficial effects of the above technical solution are as follows: The instruction input module receives the loading instruction signal and the roller lifting instruction signal from the external input. The logic control module is connected to the output end of the instruction input module. It generates a reversing control signal according to the loading instruction signal or the roller lifting instruction signal, and executes the interlock logic of the loading action and the roller lifting action to prevent the two instructions from taking effect at the same time. The execution drive module is connected to the output end of the logic control module and is used to drive the action of valves 3.1 and 3.2 of the double electromagnetic reversing valve group in the coal mill oil circuit board. The locking safety module controls the mechanical locking and release of the oil cylinder by monitoring the pilot control port pressure status of hydraulic control check valves 4.1A and 4.2A in the coal mill oil circuit board. Interlocking mechanisms eliminate interference caused by misoperation, redundant dual-valve drive reduces the risk of solenoid valve jamming, and pilot pressure monitoring provides real-time feedback on the locking status, thus improving the safety level.

[0028] Example 6 Based on embodiment 5, the logic control module includes an action interlock submodule and a redundancy verification submodule; The action interlock submodule is used to automatically block the roller lifting command signal when the loading command signal is detected to be activated, and to automatically block the loading command signal when the roller lifting command signal is detected to be activated. The redundancy verification submodule is used to receive the position sensor signals of valve 3.1 and valve 3.2 in real time. When the valve position deviation of valve 3.1 and valve 3.2 exceeds 10% of the stroke, it sends a stop command to the execution drive module.

[0029] The working principle and beneficial effects of the above technical solution are as follows: The logic control module includes an action interlock submodule and a redundancy check submodule. The action interlock submodule is used to automatically block the roller lifting command signal when the load command signal is detected to be activated, and to automatically block the load command signal when the roller lifting command signal is detected to be activated. The redundancy check submodule is used to receive the position sensor signals of valve 3.1 and valve 3.2 in real time, and to send a stop command to the execution drive module when the valve position deviation of valve 3.1 and valve 3.2 exceeds 10% of the stroke. It achieves 100% command interlocking, eliminating the risk of malfunction; valve position deviation shutdown prevents uneven wear of the grinding rollers caused by valve core asynchrony.

[0030] Example 7 Based on Embodiment 5, the locking safety module includes a pilot pressure monitoring submodule and an emergency locking submodule; The pilot pressure monitoring submodule is used to detect the oil pressure value of the pilot control port of the hydraulic check valve 4.1A and the pilot control port of the hydraulic check valve 4.2A in real time. When the pressure value is lower than 5MPa, a low pressure alarm is triggered. The emergency locking submodule is used to forcibly close the oil passages of hydraulic check valves 4.1A, 4.1B, 4.2A, and 4.2B when the pressure value of the main pressure oil passage P of the system is lower than 8MPa.

[0031] The working principle and beneficial effects of the above technical solution are as follows: The locking safety module includes a pilot pressure monitoring submodule and an emergency locking submodule. The pilot pressure monitoring submodule is used to detect the oil pressure value of the pilot control port of the hydraulic check valve 4.1A and the pilot control port of the hydraulic check valve 4.2A in real time. When the pressure value is lower than 5MPa, a low pressure alarm is triggered. The emergency locking submodule is used to forcibly close the oil passage of the hydraulic check valve 4.1A, hydraulic check valve 4.1B, hydraulic check valve 4.2A and hydraulic check valve 4.2B when the pressure value of the main pressure oil passage P of the system is lower than 8MPa. Low-pressure alarms can warn of pilot oil circuit blockage or leakage; automatic pressure loss locking can prevent grinding rollers from falling when the system leaks; dual-stage pressure thresholds enable graded response to faults.

[0032] Example 8 Based on Embodiment 5, it also includes a pressure control module and a status monitoring module. The pressure control module includes a pressure closed-loop submodule and a ramp control submodule. The status monitoring module includes a pressure sensor group and a valve position feedback unit. The pressure closed-loop submodule is used to receive the real-time load sensor signal of the coal mill and dynamically adjust the current control signal of the proportional relief valve so that the pressure value of the working oil passage A1 is maintained within the range of ±0.5MPa. The ramp control submodule is used to control the pressure setpoint of the proportional relief valve to increase linearly to the target pressure value at a rate not exceeding 2 MPa per second after the loading command is activated. The pressure sensor group includes a first pressure sensor, a second pressure sensor and a third pressure sensor. The first pressure sensor is installed on the main pressure oil passage P, the second pressure sensor is installed on the working oil passage A1, and the third pressure sensor is installed on the working oil passage A2. The valve position feedback unit includes a first displacement sensor and a second displacement sensor. The first displacement sensor is used to detect the actual position of the valve core of valve 3.1, and the second displacement sensor is used to detect the actual position of the valve core of valve 3.2.

[0033] The working principle and beneficial effects of the above technical solution are as follows: The reversing control device also includes a pressure control module and a status monitoring module. The pressure control module includes a pressure closed-loop submodule and a ramp control submodule. The status monitoring module includes a pressure sensor group and a valve position feedback unit. The pressure closed-loop submodule is used to receive the real-time load sensor signal of the coal mill and dynamically adjust the current control signal of the proportional relief valve so that the pressure value of the working oil passage A1 is maintained within the range of ±0.5MPa of the set value. The ramp control submodule is used to control the pressure set value of the proportional relief valve to increase linearly to the target pressure value at a rate not exceeding 2MPa per second after the loading command is activated. The pressure sensor group includes a first pressure sensor, a second pressure sensor and a third pressure sensor, which are respectively installed on the main pressure oil passage P, the working oil passage A1 and the working oil passage A2. The valve position feedback unit includes a first displacement sensor and a second displacement sensor, which are respectively used to detect the actual position of the valve core of valve 3.1 and valve 3.2. Pressure closed-loop control adapts to load fluctuations and ensures pressure control accuracy; ramp speed limiting avoids pressure shocks that could damage the seals; multi-point pressure monitoring can diagnose blockages, leaks, and other faults in real time; and valve position feedback calibrates the solenoid valve's actuation accuracy.

[0034] Example 9 Based on Example 5, a grinding roller wear state prediction module is also included, which includes: A high-frequency pressure sensor is installed on the working oil passage A1 of the coal mill oil circuit board to collect hydraulic pressure pulsation signals in real time. The spectrum analysis unit, electrically connected to the high-frequency pressure sensor, is used to perform a fast Fourier transform on the pressure signal and extract the amplitude components of a preset frequency range at each acquisition time. and corresponding frequencies ; The wear index calculation unit, electrically connected to the spectrum analysis unit, is used to calculate the real-time wear index based on the amplitude component An and the corresponding frequency fn extracted by the spectrum analysis unit. ;in, This is the real-time wear index. For the i-th acquisition time, the amplitude components of the preset frequency range are defined. The frequency corresponding to the preset frequency range at the i-th acquisition time, where K is the material coefficient of the grinding roller; The control execution unit is electrically connected to the wear index calculation unit. When the wear index exceeds the wear index set threshold, it reduces the loading pressure set value by 10% and triggers an audible and visual alarm.

[0035] The working principle and beneficial effects of the above technical solution are as follows: The reversing control device also includes a grinding roller wear state prediction module. This module includes a high-frequency pressure sensor, a spectrum analysis unit, a wear index calculation unit, and a control execution unit. The high-frequency pressure sensor is installed on the working oil passage A1 of the coal mill oil circuit board and is used to collect hydraulic pressure pulsation signals in real time. The spectrum analysis unit is electrically connected to the high-frequency pressure sensor and is used to perform a fast Fourier transform on the pressure signal to extract the amplitude component and corresponding frequency of the preset frequency range at each acquisition time. The wear index calculation unit is electrically connected to the spectrum analysis unit and is used to calculate the real-time wear index according to the formula based on the amplitude component and corresponding frequency extracted by the spectrum analysis unit, where is the real-time wear index, is the amplitude component of the preset frequency range at the i-th acquisition time, is the corresponding frequency of the preset frequency range at the i-th acquisition time, and K is the grinding roller material coefficient. The control execution unit is electrically connected to the wear index calculation unit and is used to reduce the load pressure setting value by 10% and trigger the audible and visual alarm when the wear index exceeds the wear index setting threshold. The wear index is calculated by formula, which quantifies the high-frequency vibration energy. The product reflects the energy released by wear, and the summation accumulates the damage. The analysis of the 10-50Hz frequency band can accurately capture the characteristic frequency of roller peeling. Reducing the load pressure setting value by 10% can delay the development of wear and extend the life of the roller. Threshold alarm can avoid sudden breakage and improve the fault warning rate.

[0036] Example 10 Based on Example 5, a valve core jamming handling module is also included, which includes: The current ripple detection unit is connected to the output terminal of the electromagnet drive circuit of valves 3.1 and 3.2, and is used to acquire the high-frequency ripple component of the operating current of valves 3.1 and 3.2 in real time. The hysteresis index calculator, electrically connected to the current ripple detection unit, is used to calculate the hysteresis index based on the high-frequency ripple component of the operating current of valves 3.1 and 3.2. A high-frequency oscillation injector is connected between the execution drive module and valves 3.1 and 3.2. It is used to superimpose a sinusoidal oscillation current with a frequency of 80Hz±5Hz and an amplitude of 20% of the rated drive current onto the coil of valve 3.1 or valve 3.2 when the sticking index is greater than the preset value of the sticking index. An automatic cleaning trigger, electrically connected to a stickiness index calculator, is used to send a circulating cleaning command to the main controller of the hydraulic system when the stickiness index decrease rate is less than a preset percentage. The actions triggered by this command include closing the proportional relief valve, controlling valves 3.1 and 3.2 to reciprocate at a frequency of 1Hz, and starting the flushing pump to circulate hydraulic oil at a flow rate of 40L / min for 10 minutes.

[0037] The working principle and beneficial effects of the above technical solution are as follows: The commutation control device also includes a valve core jamming processing module. This module includes a current ripple detection unit, a jamming index calculator, a high-frequency oscillation injector, and an automatic cleaning trigger. The current ripple detection unit is connected to the output terminals of the electromagnet drive circuits of valves 3.1 and 3.2, and is used to collect the high-frequency ripple component of the operating current of valves 3.1 and 3.2 in real time. The jamming index calculator is electrically connected to the current ripple detection unit and is used to calculate the jamming index based on the high-frequency ripple component of the operating current of valves 3.1 and 3.2. The high-frequency oscillation injector is connected to the actuator drive circuit. Between the actuator module and valves 3.1 and 3.2, a sinusoidal oscillating current with a frequency of 80Hz±5Hz and an amplitude of 20% of the rated drive current is superimposed on the coil of valve 3.1 or valve 3.2 when the sticking index is greater than the preset value of the sticking index. The automatic cleaning trigger is electrically connected to the sticking index calculator and is used to send a circulation cleaning command to the main controller of the hydraulic system when the sticking index decrease rate is less than the preset percentage. The actions triggered by this command include closing the proportional relief valve, controlling valves 3.1 and 3.2 to reciprocate at a frequency of 1Hz, and starting the flushing pump to circulate hydraulic oil at a flow rate of 40L / min for 10 minutes. The sticking index is calculated by formula, and the energy of current fluctuation is quantified integrally. It reflects the valve core resistance and the degree of sticking is accumulated integrally. The 80Hz oscillation excites the mechanical resonance of the valve core, which can break up the gum deposits. The circulating cleaning command is linked to the hydraulic system to perform efficient flushing, which can remove contaminants, reduce the frequency of disassembly and maintenance, and extend the maintenance interval.

[0038] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A coal mill oil circuit board, characterized in that: include: The valve block body has interconnected main pressure oil passage P, return oil passage T, working oil passage A1, working oil passage B1, working oil passage A2 and working oil passage B2. The proportional relief valve is integrated into the main pressure oil passage P inlet of the valve block body and is used to set the loading pressure; The dual solenoid directional valve assembly includes valves 3.1 and 3.2, which are connected in parallel downstream of the proportional relief valve. Both valves 3.1 and 3.2 contain two three-position four-way solenoid valves. The working oil passage assembly, including working oil passage A1, working oil passage B1, working oil passage A2 and working oil passage B2, is used to communicate with valves 3.1 and 3.2; Two sets of hydraulically controlled check valve groups, each group containing two hydraulically controlled check valves. The first set of hydraulically controlled check valves includes hydraulically controlled check valve 4.1A and hydraulically controlled check valve 4.1B, and the second set of hydraulically controlled check valves includes hydraulically controlled check valve 4.2A and hydraulically controlled check valve 4.2B. Hydraulically controlled check valves 4.1A, 4.1B, 4.2A, and 4.2B are used to connect the double solenoid directional valve group and the working oil passage group. Two accumulators, including accumulator one and accumulator two, are connected to working oil passage A1 and working oil passage A2 respectively through accumulator interface 5.1 and accumulator interface 5.2; The safety relief valve has its inlet connected to the main pressure oil passage P and its outlet connected to the return oil passage T. An online particle counter, embedded in the inlet of the return oil passage T, is used to detect in real time the number of contaminant particles with a particle size larger than a preset particle size in the oil in the return oil passage T. A spiral cooling channel is located inside the valve block body. A semiconductor temperature control chip is integrated on the outer wall of the spiral cooling channel. The inlet and outlet of the spiral cooling channel are connected to the external coolant circulation system, respectively.

2. The oil circuit board for a coal mill according to claim 1, characterized in that: The P port of valves 3.1 and 3.2 is connected to the main pressure oil passage P, the T port of valves 3.1 and 3.2 is connected to the return oil passage T, the A port of valve 3.1 and the B port of valve 3.2 are respectively used to connect to the working oil passage A1 and the working oil passage B1, and the A port of valve 3.2 and the B port of valve 3.2 are respectively used to connect to the working oil passage A2 and the working oil passage B2.

3. The oil circuit board for a coal mill according to claim 1, characterized in that: One end of the hydraulic control check valve 4.1A and hydraulic control check valve 4.1B is connected to port A and port B of valve 3.1, respectively, and the other end of the hydraulic control check valve 4.1A and hydraulic control check valve 4.1B is connected to working oil passage A1 and working oil passage B1, respectively. One end of the hydraulic control check valve 4.2A and hydraulic control check valve 4.2B is connected to port A and port B of valve 3.2, respectively, and the other end of the hydraulic control check valve 4.2A and hydraulic control check valve 4.2B is connected to working oil passage A2 and working oil passage B2, respectively. Among them, the pilot control ports of hydraulic check valve 4.1A and hydraulic check valve 4.2A are connected to the main pressure oil passage P through independent oil circuits.

4. The oil circuit board for a coal mill according to claim 3, characterized in that: One-way throttle valve one and one-way throttle valve two are respectively provided between the accumulator interface 5.1 and accumulator interface 5.2 and the working oil passage A1 and working oil passage A2. The one-way throttle valves are used to control the charging and discharging speed of accumulator one and accumulator two.

5. A reversing control device for controlling a coal mill hydraulic circuit board as described in any one of claims 1-4, characterized in that: include: The instruction input module is used to receive external input loading instruction signals and roller lifting instruction signals; The logic control module is connected to the output of the instruction input module. It is used to generate a reversing control signal based on the loading instruction signal or the roller lifting instruction signal, and to execute the interlock logic between the loading action and the roller lifting action, preventing the two instructions from taking effect at the same time. The execution drive module is connected to the output of the logic control module and is used to drive the operation of valves 3.1 and 3.2 in the double electromagnetic directional valve group in the coal mill oil circuit board. The locking safety module is used to control the mechanical locking and releasing of the hydraulic cylinder by monitoring the pilot control port pressure status of the hydraulic control check valves 4.1A and 4.2A in the oil circuit board of the coal mill.

6. A commutation control device according to claim 5, characterized in that: The logic control module includes an action interlock submodule and a redundancy check submodule; The action interlock submodule is used to automatically block the roller lifting command signal when the loading command signal is detected to be activated, and to automatically block the loading command signal when the roller lifting command signal is detected to be activated. The redundancy verification submodule is used to receive the position sensor signals of valve 3.1 and valve 3.2 in real time. When the valve position deviation of valve 3.1 and valve 3.2 exceeds 10% of the stroke, it sends a stop command to the execution drive module.

7. A commutation control device according to claim 5, characterized in that: The locking safety module includes a pilot pressure monitoring submodule and an emergency locking submodule; The pilot pressure monitoring submodule is used to detect the oil pressure value of the pilot control port of the hydraulic check valve 4.1A and the pilot control port of the hydraulic check valve 4.2A in real time. When the pressure value is lower than 5MPa, a low pressure alarm is triggered. The emergency locking submodule is used to forcibly close the oil passages of hydraulic check valves 4.1A, 4.1B, 4.2A, and 4.2B when the pressure value of the main pressure oil passage P of the system is lower than 8MPa.

8. A commutation control device according to claim 5, characterized in that: It also includes a pressure control module and a status monitoring module. The pressure control module includes a pressure closed-loop submodule and a ramp control submodule. The status monitoring module includes a pressure sensor group and a valve position feedback unit. The pressure closed-loop submodule is used to receive the real-time load sensor signal of the coal mill and dynamically adjust the current control signal of the proportional relief valve so that the pressure value of the working oil passage A1 is maintained within the range of ±0.5MPa. The ramp control submodule is used to control the pressure setpoint of the proportional relief valve to increase linearly to the target pressure value at a rate not exceeding 2 MPa per second after the loading command is activated. The pressure sensor group includes a first pressure sensor, a second pressure sensor and a third pressure sensor. The first pressure sensor is installed on the main pressure oil passage P, the second pressure sensor is installed on the working oil passage A1, and the third pressure sensor is installed on the working oil passage A2. The valve position feedback unit includes a first displacement sensor and a second displacement sensor. The first displacement sensor is used to detect the actual position of the valve core of valve 3.1, and the second displacement sensor is used to detect the actual position of the valve core of valve 3.

2.

9. A commutation control device according to claim 5, characterized in that: It also includes a grinding roller wear condition prediction module, which includes: A high-frequency pressure sensor is installed on the working oil passage A1 of the coal mill oil circuit board to collect hydraulic pressure pulsation signals in real time. The spectrum analysis unit, electrically connected to the high-frequency pressure sensor, is used to perform a fast Fourier transform on the pressure signal and extract the amplitude components of a preset frequency range at each acquisition time. and corresponding frequencies ; The wear index calculation unit, electrically connected to the spectrum analysis unit, is used to calculate the real-time wear index based on the amplitude component An and the corresponding frequency fn extracted by the spectrum analysis unit. ;in, This is the real-time wear index. For the i-th acquisition time, the amplitude components of the preset frequency range are defined. The frequency corresponding to the preset frequency range at the i-th acquisition time, where K is the material coefficient of the grinding roller; The control execution unit is electrically connected to the wear index calculation unit. When the wear index exceeds the wear index set threshold, it reduces the loading pressure set value by 10% and triggers an audible and visual alarm.

10. A commutation control device according to claim 5, characterized in that: It also includes a valve core jamming handling module, which includes: The current ripple detection unit is connected to the output terminal of the electromagnet drive circuit of valves 3.1 and 3.2, and is used to acquire the high-frequency ripple component of the operating current of valves 3.1 and 3.2 in real time. The hysteresis index calculator, electrically connected to the current ripple detection unit, is used to calculate the hysteresis index based on the high-frequency ripple component of the operating current of valves 3.1 and 3.

2. A high-frequency oscillation injector is connected between the execution drive module and valves 3.1 and 3.

2. It is used to superimpose a sinusoidal oscillation current with a frequency of 80Hz±5Hz and an amplitude of 20% of the rated drive current onto the coil of valve 3.1 or valve 3.2 when the sticking index is greater than the preset value of the sticking index. An automatic cleaning trigger, electrically connected to a stickiness index calculator, is used to send a circulating cleaning command to the main controller of the hydraulic system when the stickiness index decrease rate is less than a preset percentage. The actions triggered by this command include closing the proportional relief valve, controlling valves 3.1 and 3.2 to reciprocate at a frequency of 1Hz, and starting the flushing pump to circulate hydraulic oil at a flow rate of 40L / min for 10 minutes.

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