A pilot flow soft closed loop primary stage amplification type flow control method, system and valve

Abstract

This invention discloses a pilot flow soft closed-loop main-stage amplification flow control method, system, and valve. The method involves determining the current signal of the pilot valve used to control the flow control valve based on the target flow signal. Based on the current signal, the valve core displacement, main valve core displacement, and main valve flow area of ​​the pilot valve are determined sequentially. The actual flow signal at the output of the flow control valve is calculated based on the main valve flow area, the pressure at the main valve inlet and outlet, and the temperature of the oil in the main valve body's internal oil passages. The target flow signal and the actual flow signal are input into a proportional amplifier to obtain a comparison current signal. The current signal and the comparison current signal are summed to obtain a current calibration value. The displacement of the pilot valve core is controlled based on the current calibration value, and the flow rate at the output of the flow control valve is determined based on the displacement of the valve core. Advantages: It can detect and control the pilot valve core displacement and flow rate without the assistance of displacement sensors or flow sensors, achieving high control accuracy and low cost.

Description

Technical Field

[0001] This invention relates to a pilot flow soft closed-loop main stage amplification flow control method, system, and valve, belonging to the field of engineering machinery technology. Background Technology

[0002] A typical flow regeneration valve uses a spool valve structure for its main valve core. It controls the displacement of the main valve core by applying force to both ends, thereby controlling the throttling area and thus the flow rate. However, due to the limitations of the spool valve structure, the valve core's movement is significantly affected by hydraulic forces, resulting in limited flow control accuracy. Furthermore, since the flow control method is throttling, with a fixed throttling area, changes in pressure across the throttling orifice (i.e., load variations) will also alter the flow rate through the orifice, significantly impacting control accuracy. Additionally, a flow sensor is installed at the pilot oil passage outlet. Since flow sensors have inherent errors, the main valve output flow rate is a proportional amplification of the pilot flow rate, posing a risk of linearly amplifying the error and resulting in low flow control accuracy.

[0003] For flow control valves used in large mining hydraulic excavators, there are currently three main technologies:

[0004] Technique 1: A displacement sensor is coaxially mounted on the main valve core to detect its displacement, and the flow rate is controlled by a controller that controls the displacement of the main valve core.

[0005] Technology 2: A flow sensor composed of a right two-position two-way cartridge valve is added. Its main valve control chamber is connected to the pilot inlet, and the flow sensor outlet is connected to the pilot valve outlet. The pilot flow is controlled by detecting the pilot flow to form a closed loop. Then, the main flow is amplified by the Valvistor valve amplification principle, which integrates the two major control principles of flow closed loop and flow amplification.

[0006] Technology 3: A pilot flow closed-loop control flow valve, which includes a pressure sensor, a pilot flow calculator, a pilot flow regulator, a displacement sensor, and a displacement regulator. The pressure sensor is installed before and after the throttling port of the pilot oil passage and is controlled by PID. The pilot valve flow is controlled in a closed loop. The flow of the proportional pilot valve does not change with the load pressure and the pressure in the upper chamber of the main valve, thereby controlling the flow of the main valve to change with the set value of the pilot valve.

[0007] The flow control valves currently used in large mining hydraulic excavators often have the following drawbacks:

[0008] 1. Generally, the main valve core of a flow regeneration valve is a slide valve structure, which has limited flow capacity. For the same flow rate, the overall valve body has a larger volume and greater pressure loss.

[0009] 2. Generally, the regeneration valve core is a slide valve structure. The displacement of the main valve core is controlled by applying force directly to both ends of the slide valve. When the flow rate is large, the movement of the main valve core is greatly affected by the hydraulic force, resulting in low flow control accuracy.

[0010] 3. Throttling control is greatly affected by load changes; the smaller the pressure difference, the smaller the flow rate, and the larger the pressure difference, the larger the flow rate.

[0011] 4. The valve output flow is controlled by controlling the pilot flow. The valve output flow is a linear amplification of the pilot flow. The control accuracy of the pilot flow has a significant impact on the valve control accuracy.

[0012] 5. Lack of operating condition identification and fault diagnosis;

[0013] 6. Flow regeneration valves with the same function have a large number of integrated plugs, occupy a large valve body space, and have a high cost. Summary of the Invention

[0014] The technical problem to be solved by the present invention is to overcome the defects of the prior art and provide a pilot flow soft closed loop main stage amplification flow control method, system and valve.

[0015] To solve the above technical problems, the present invention provides a pilot flow soft closed-loop master-stage amplification flow control method, comprising:

[0016] Obtain the target flow signal Q from the output of the flow control valve. s The pressure at the main valve inlet and outlet of the flow control valve and the temperature of the oil in the oil passage inside the main valve body are collected.

[0017] Based on the target flow signal Q s Determine the current signal I of the pilot valve used to control the flow control valve, determine the displacement of the pilot valve core of the flow control valve based on the displacement-force feedback control method according to the current signal I, determine the displacement of the main valve core of the flow control valve according to the displacement of the pilot valve core, and determine the flow area of ​​the main valve of the flow control valve according to the displacement of the main valve core.

[0018] The actual flow signal Q at the output of the flow control valve is calculated based on the main valve's flow area, the pressure at the main valve's inlet and outlet, and the temperature of the oil in the main valve body's internal oil passages. f ;

[0019] The target flow signal Q s and actual flow signal Q f The input is processed by a proportional amplifier to obtain a comparison current signal ΔI. The current signal I and the comparison current signal ΔI are then summed to obtain the current calibration value I. s ;

[0020] According to the current calibration value I sThe displacement of the valve core of the pilot valve, which is based on the displacement-force feedback control method, is controlled, and the flow rate at the output of the flow control valve is determined based on the displacement of the valve core.

[0021] Furthermore, the target flow signal Q s and actual flow signal Q f The input is processed by a proportional amplifier to obtain a comparison current signal ΔI. The current signal I and the comparison current signal ΔI are then summed to obtain the current calibration value I. s ,include:

[0022] The target flow signal Q is amplified by a proportional amplifier. s and actual flow signal Q f The calibration process involves converting the calibrated signal into a current signal and outputting it to a current calibration device. The current calibration device then integrates the received current signal I with the comparison current signal ΔI output from the proportional amplifier to output the current calibration value I. s .

[0023] Furthermore, the calibration value I based on the current... s Controlling the displacement of the pilot valve based on displacement-force feedback control, and determining the flow rate at the output of the flow control valve based on the displacement of the pilot valve, including:

[0024] Current calibration value I s The proportional electromagnet in the displacement-force feedback control module of the flow control valve is input. When the proportional electromagnet operates, it adjusts the size of the throttle orifice in the displacement-force feedback control module, thereby adjusting the displacement of the pilot valve.

[0025] Furthermore, it also includes:

[0026] When the pressure signal, temperature signal and calculated actual flow signal Q of the flow control valve are collected... f When there is a deviation from the corresponding parameter originally preset in the controller and the deviation exceeds the preset value, a fault alarm will be triggered.

[0027] A pilot flow soft closed-loop master-stage amplification flow control system includes:

[0028] The data acquisition module is used to acquire the target flow signal Q at the output of the flow control valve. s The pressure at the main valve inlet and outlet of the flow control valve and the temperature of the oil in the oil passage inside the main valve body are collected.

[0029] The determination module is used to determine the target flow signal Q. sDetermine the current signal I of the pilot valve used to control the flow control valve, determine the displacement of the pilot valve core of the flow control valve based on the displacement-force feedback control method according to the current signal I, determine the displacement of the main valve core of the flow control valve according to the displacement of the pilot valve core, and determine the flow area of ​​the main valve of the flow control valve according to the displacement of the main valve core.

[0030] The first calculation module is used to calculate the actual flow signal Q at the output of the flow control valve based on the main valve's flow area, the pressure at the main valve's inlet and outlet, and the temperature of the oil in the oil passage inside the main valve body. f ;

[0031] The second calculation module is used to process the target flow signal Q. s and actual flow signal Q f The input is processed by a proportional amplifier to obtain a comparison current signal ΔI. The current signal I and the comparison current signal ΔI are then summed to obtain the current calibration value I. s ;

[0032] The control module is used to calibrate the current value I. s The displacement of the valve core of the pilot valve, which is based on the displacement-force feedback control method, is controlled, and the flow rate at the output of the flow control valve is determined based on the displacement of the valve core.

[0033] Furthermore, the control module is used to set the current calibration value I. s The proportional electromagnet in the displacement-force feedback control module of the flow control valve is input. When the proportional electromagnet operates, it adjusts the size of the throttle orifice in the displacement-force feedback control module, thereby adjusting the displacement of the pilot valve.

[0034] A pilot flow soft closed-loop main stage amplification flow control valve includes: a valve body, a controller, a proportional amplifier, a current calibration device, and a high-precision fast calculator. The valve body is provided with a main valve core assembly, a pilot valve core assembly, a temperature sensor, a pressure sensor, and a displacement-force feedback end cap assembly.

[0035] The pressure sensor is installed at the inlet and outlet of the main oil passage of the flow control valve, and the temperature sensor is installed at the outlet of the main oil passage of the flow control valve.

[0036] The signals collected by the temperature and pressure sensors are transmitted to a high-precision, high-speed calculator.

[0037] Controller, used to determine the target flow rate signal Q sDetermine the current signal I of the pilot valve used to control the flow control valve, determine the displacement of the pilot valve core of the flow control valve based on the displacement-force feedback control method according to the current signal I, determine the displacement of the main valve core assembly according to the displacement of the pilot valve core, and determine the main valve flow area of ​​the flow control valve according to the displacement of the main valve core.

[0038] A high-precision, fast calculator is used to calculate the actual flow signal Q at the output of the flow control valve based on the main valve's flow area, the pressure at the main valve's inlet and outlet, and the temperature of the oil in the main valve body's internal oil passages. f ;

[0039] A proportional amplifier is used to amplify the target flow signal Q. s and actual flow signal Q f The comparison process yields a comparison current signal ΔI, which is output to a current calibration device. The current calibration device integrates the calculated current signal I and the comparison current signal ΔI to obtain the current calibration value I. s ;

[0040] The displacement-force feedback end cap assembly includes a proportional electromagnet, a displacement-force feedback end cap valve core, and a displacement-force feedback end cap; the proportional electromagnet is used to respond to a current calibration value I. s Then, it operates, moving the displacement-force feedback end cap valve core to the corresponding current calibration value I. s The position controls the size of the throttling orifice in the displacement-force feedback control end cover, and the throttling orifice in the displacement-force feedback control end cover is used to adjust the pressure in the control chamber of the displacement-force feedback end cover.

[0041] The pilot valve core assembly is used to control the displacement of the main valve core in the main valve core assembly according to the pressure of the pilot oil, thereby controlling the output flow.

[0042] Furthermore, the main valve core of the main valve core assembly adopts a cone valve structure.

[0043] Furthermore, the controller is used to process the pressure signal, temperature signal, and calculated actual flow signal Q from the acquired flow control valve. f When there is a deviation from the corresponding parameter originally preset in the controller and the deviation exceeds the preset value, a fault alarm will be triggered.

[0044] A hydraulic engineering machine includes a pilot flow soft closed-loop main stage amplification flow control valve.

[0045] The beneficial effects achieved by this invention are as follows:

[0046] 1. The pilot valve core control method is a control method of displacement-force feedback closed loop plus overall electrical feedback external closed loop. Without the assistance of displacement sensor and flow sensor, it can realize the detection and control of pilot valve core displacement and flow. The control accuracy is high, the number of plug-ins is small, and the cost is low.

[0047] 2. The flow control valve is equipped with differential pressure sensors and temperature sensors at the inlet and outlet. The controller can detect, control, identify operating conditions and diagnose faults of the total output flow of the valve. This reduces the impact of load changes on the output flow of the flow control valve, improves the flow control accuracy, and reduces the impact of load changes on the output flow control accuracy of the flow control valve.

[0048] 3. The main valve core of the flow control valve adopts a cone valve structure. Compared with the flow regeneration valve, which adopts a slide valve structure for the main valve core, the flow control valve has a smaller size under the same flow specification, thus occupying less space and saving layout space.

[0049] 4. The pilot valve core control method is a control method of displacement-force feedback closed loop plus overall electrical feedback external closed loop, which combines the principle of flow amplification. The output flow of the flow control valve is a proportional amplification of the pilot flow. Compared with the flow regeneration valve with the main valve core as a slide valve structure, it reduces the impact of hydraulic force on the valve output flow control accuracy. Attached Figure Description

[0050] Figure 1 This is a schematic diagram illustrating the working principle of the present invention;

[0051] Figure 2 This is a schematic diagram of the valve structure. Figure 1 ;

[0052] Figure 3 This is a schematic diagram of the valve structure. Figure 2 ;

[0053] 1-Valve body, 2-Retaining ring, 3-O-ring, 4-Valve sleeve assembly, 5-Main valve core assembly, 6-Pilot valve core assembly, 7-Spring, 8-Spring, 9-End cover assembly, 12-Plug, 13-Screw plug, 15-Displacement-force feedback end cover assembly, 22-Differential pressure sensor, 23-Temperature sensor. Detailed Implementation

[0054] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention.

[0055] Example 1: This invention provides a pilot flow soft closed-loop master-stage amplification flow control method, comprising:

[0056] Obtain the target flow signal Q from the output of the flow control valve. sThe pressure at the main valve inlet and outlet of the flow control valve and the temperature of the oil in the oil passage inside the main valve body are collected.

[0057] Based on the target flow signal Q s Determine the current signal I of the pilot valve used to control the flow control valve. Based on the current signal I, determine the displacement of the pilot valve core of the flow control valve based on the displacement-force feedback control method (first control the displacement of the valve core in the displacement-force feedback end cover, adjust the oil pressure in its control chamber, so that the pressure acting on the left end of the pilot valve core changes, so that its displacement changes). Based on the displacement of the pilot valve core, determine the displacement of the main valve core of the flow control valve. Based on the displacement of the main valve core, determine the main valve flow area of ​​the flow control valve.

[0058] The actual flow signal Q at the output of the flow control valve is calculated based on the main valve's flow area, the pressure at the main valve's inlet and outlet, and the temperature of the oil in the main valve body's internal oil passages. f ;

[0059] The target flow signal Q s and actual flow signal Q f The input is processed by a proportional amplifier to obtain a comparison current signal ΔI. The current signal I and the comparison current signal ΔI are then summed to obtain the current calibration value I. s ;

[0060] According to the current calibration value I s The displacement of the valve core of the pilot valve, controlled by a displacement-force feedback control method, is measured (via the current calibration value I). s The displacement of the valve core in the control force feedback end cover is controlled, and the oil pressure in its control chamber is adjusted, so that the pressure acting on the left end of the pilot valve core changes, and the displacement of the pilot valve core is adjusted, thereby controlling the displacement of the main valve core. The flow rate at the output end of the flow control valve is determined according to the displacement of the valve core.

[0061] The target flow signal Q s and actual flow signal Q f The input is processed by a proportional amplifier to obtain a comparison current signal ΔI. The current signal I and the comparison current signal ΔI are then summed to obtain the current calibration value I. s ,include:

[0062] The target flow signal Q is amplified by a proportional amplifier. s and actual flow signal Q f The calibration process involves converting the calibrated signal into a current signal and outputting it to a current calibration device. The current calibration device then integrates the received current signal I with the comparison current signal ΔI output from the proportional amplifier to output the current calibration value I. s .

[0063] The current calibration value I s The opening and closing size of the pilot valve of the flow control valve is controlled, and the flow rate at the output of the flow control valve is determined based on the opening and closing size of the pilot valve, including:

[0064] Current calibration value I s The proportional electromagnet in the displacement-force feedback control module of the flow control valve is input. When the proportional electromagnet is working, it adjusts the size of the pilot valve throttle orifice, thereby adjusting the opening and closing size of the pilot valve.

[0065] Also includes:

[0066] When the pressure signal, temperature signal and calculated actual flow signal Q of the flow control valve are collected... f When there is a deviation from the corresponding parameter originally preset in the controller and the deviation exceeds the preset value, a fault alarm will be triggered.

[0067] Actual flow signal Q f The calculation formula is:

[0068]

[0069] Where K(T): temperature correction factor; C d : Flow correction coefficient; A(x): Flow area (i.e., throttling orifice area), its size depends on the main valve core displacement x, and is a linear relationship; ρ: Oil density; P a P b : Oil pressure at both ends of the main valve core of the flow control valve.

[0070] The formula for calculating the comparison current signal ΔI is:

[0071] ΔI=K(Q s -Q f )

[0072] Where K is the flow correction coefficient, the current magnitude depends on the flow rate and has a linear relationship with the flow signal.

[0073] Example 2: The present invention also provides a pilot flow soft closed-loop master-stage amplification flow control system, comprising:

[0074] The data acquisition module is used to acquire the target flow signal Q at the output of the flow control valve. s The pressure at the main valve inlet and outlet of the flow control valve and the temperature of the oil in the oil passage inside the main valve body are collected.

[0075] The determination module is used to determine the target flow signal Q. sDetermine the current signal I of the pilot valve used to control the flow control valve, determine the displacement of the pilot valve core of the flow control valve based on the displacement-force feedback control method according to the current signal I, determine the displacement of the main valve core of the flow control valve according to the displacement of the pilot valve core, and determine the flow area of ​​the main valve of the flow control valve according to the displacement of the main valve core.

[0076] The first calculation module is used to calculate the actual flow signal Q at the output of the flow control valve based on the main valve's flow area, the pressure at the main valve's inlet and outlet, and the temperature of the oil in the oil passage inside the main valve body. f ;

[0077] The second calculation module is used to process the target flow signal Q. s and actual flow signal Q f The input is processed by a proportional amplifier to obtain a comparison current signal ΔI. The current signal I and the comparison current signal ΔI are then summed to obtain the current calibration value I. s ;

[0078] The control module is used to calibrate the current value I. s The displacement of the valve core of the pilot valve, which is based on the displacement-force feedback control method, is controlled, and the flow rate at the output of the flow control valve is determined based on the displacement of the valve core.

[0079] Specifically, the control module is used to set the current calibration value I. s The proportional electromagnet in the displacement-force feedback control module of the flow control valve is input. When the proportional electromagnet operates, it adjusts the size of the throttle orifice in the displacement-force feedback control module, thereby adjusting the displacement of the pilot valve.

[0080] Example 3: This invention discloses a pilot-operated soft closed-loop main-stage amplification flow control valve. The flow control valve eliminates the spool valve structure of the main valve core and adopts a cone valve structure. Under the same flow specifications, the overall valve body structure is smaller, saving space and facilitating layout and installation. Under high pressure and high flow conditions, the spool valve is greatly affected by hydraulic forces during operation, easily leading to inaccurate control precision. Furthermore, the general flow regeneration valve controls flow by directly applying pilot pressure to both ends of the main valve core, adjusting the throttling orifice area by controlling the valve core to control the total output flow of the valve. When the load changes, the pressure difference across the throttling orifice changes, significantly affecting the total output flow of the valve and impacting control precision. The flow control valve utilizes the principle of flow amplification. Through the feedback throttling of the pilot orifice and the main valve core, the displacement of the main valve core is proportional to the displacement of the pilot valve core. That is, the total output flow of the flow control valve is a proportional amplification of the pilot flow. By controlling the displacement of the pilot valve core, the valve's output flow can be controlled, reducing the impact of hydraulic forces on flow control accuracy and improving control precision. Differential pressure sensors and temperature sensors are installed at the inlet and outlet of the main oil passage to detect the total output flow and operating conditions. The pilot valve core control method uses a displacement-force feedback closed loop plus an overall electrical feedback external closed loop to identify and calibrate the displacement of the pilot valve core and the main valve core, thereby achieving precise flow control. Compared to a flow regeneration valve with equivalent functions, it has fewer components, lower cost, higher control precision, and built-in fault diagnosis function, which can promptly detect and diagnose the valve's operating status, improving the stability of the entire system.

[0081] Figure 1 This is a schematic diagram of the principle. Figure 2 , Figure 3The diagram shows the structure of a flow control valve, which consists of a valve body 1, a retaining ring 2, an O-ring 3, a valve sleeve assembly 4, a main valve core assembly 5, a pilot valve core assembly 6, a spring 7, a spring 8, an end cap assembly 9, a plug 12, a screw plug 13, a displacement-force feedback end cap assembly 15, a differential pressure sensor 22, a temperature sensor 23, a controller, a high-precision fast calculator, a proportional amplifier, and a current calibration device. When the pilot valve core is in its initial position, oil enters through the inlet, flows through the internal oil passage of the main valve core, and acts on the left side of the valve core via the check valve. Because the check valve inside the pilot valve core is locked in reverse, the oil pressure only acts on the right end face of the main valve core, causing the valve core to press tightly against the sealing end face; at this time, no oil flows through. When the valve operates, the controller and high-precision fast calculator receive the input flow signal. The controller converts the input flow signal into a current signal and a flow signal respectively through calculation. The current signal is output to the current calibration device, and the flow signal is output to the proportional amplifier. The high-precision fast calculator can calculate the displacement based on the current signal from the controller, thus determining the pilot valve core position. Since the displacement of the main valve is proportional to the displacement of the pilot valve core, the displacement of the main valve core can be calculated. Subsequently, the flow area of ​​the main oil passage throttle orifice can be calculated. Using signals from the temperature sensor and differential pressure sensor, along with the throttle orifice area, the output flow rate of the main valve can be calculated. The high-precision calculator outputs the calculated flow signal to a proportional amplifier. The proportional amplifier calibrates the flow signals transmitted from the controller and the high-precision calculator, converting the calibrated signal into a current signal, which is then output to a current calibration device. The current calibration device integrates the current signals received from the controller and the proportional amplifier, outputting the current to the displacement-force feedback end cap. The proportional electromagnet operates, and driven by the iron core, the valve core in the displacement-force feedback end cover moves to the set position. At this time, the throttling port in the displacement-force feedback end cover opens, and part of the oil flows from the oil inlet of the valve core through the throttling port and is discharged from the leakage port. The pressure in the control chamber acting on the left side of the pilot valve core decreases. Driven by the pilot pressure acting on the right side of the pilot valve core, the pilot valve core overcomes the spring force and the pressure in the control chamber on the left and moves to the right to the set position. The oil in the main valve inlet of the flow control valve enters the pilot chamber through the main oil passage and the check valve, and through the feedback narrow groove. The oil entering the pilot chamber reaches the pilot chamber through the pilot throttling port and the pilot oil passage. At the oil outlet, the oil pressure on the right side of the main valve core decreases due to the flow of oil. Under the pressure exerted on the right side of the main valve core by the inlet, outlet, and oil outlet, the main valve core overcomes the spring force and the pressure acting on the left side and opens. The main valve core moves to the left to the set position, achieving precise flow control. When the pressure or temperature at the oil outlet changes, the differential pressure sensor and temperature sensor feed the signal back to the high-precision fast calculator. The high-precision fast calculator converts the signal into a flow signal and outputs it to the proportional amplifier. The proportional amplifier calculates the flow signals input from the controller and the calculator respectively, and converts the result into a current signal and outputs it to the current calibration device.The current calibration device integrates the current signals received from the controller and proportional amplifier, and outputs the current to the proportional electromagnet in the displacement-force feedback end cap. The electromagnet operates, and under the drive of the iron core, the valve core in the displacement-force feedback end cap moves to the set position. Subsequent operation is the same as described above and will not be elaborated further, thus achieving the flow maintenance function. When there is a deviation between the valve's transmitted signal and the received feedback signal and the corresponding preset parameters in the controller, the controller will promptly issue an alarm, achieving valve fault diagnosis and real-time detection functions.

[0082] Example 4: The pilot flow soft closed-loop main stage amplification flow control valve disclosed in this invention is applied to large mining hydraulic excavators with a capacity of 200 to 400 tons.

[0083] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A pilot flow soft closed-loop master-stage amplification flow control method, characterized in that, include: Obtain the target flow signal Q from the output of the flow control valve. s The pressure at the main valve inlet and outlet of the flow control valve and the temperature of the oil in the oil passage inside the main valve body are collected. Based on the target flow signal Q s Determine the current signal I of the pilot valve used to control the flow control valve, determine the displacement of the pilot valve core of the flow control valve based on the displacement-force feedback control method according to the current signal I, determine the displacement of the main valve core of the flow control valve according to the displacement of the pilot valve core, and determine the flow area of ​​the main valve of the flow control valve according to the displacement of the main valve core. The actual flow signal Q at the output of the flow control valve is calculated based on the main valve's flow area, the pressure at the main valve's inlet and outlet, and the temperature of the oil in the main valve body's internal oil passages. f ; The target flow signal Q s and actual flow signal Q f The input is processed by a proportional amplifier to obtain a comparison current signal ΔI. The current signal I and the comparison current signal ΔI are then summed to obtain the current calibration value I. s This includes: amplifying the target flow signal Q using a proportional amplifier. s and actual flow signal Q f The calibration process involves converting the calibrated signal into a current signal and outputting it to a current calibration device. The current calibration device then integrates the received current signal I with the comparison current signal ΔI output from the proportional amplifier to output the current calibration value I. s ; According to the current calibration value I s The displacement of the valve core of the pilot valve based on the displacement-force feedback control method is controlled, and the flow rate at the output end of the flow control valve is determined according to the displacement of the valve core. This also includes: the pressure signal and temperature signal of the flow control valve collected, as well as the calculated actual flow signal Q. f When the deviation from the corresponding parameter originally preset in the controller exceeds the preset value, a fault alarm is triggered; ； in, K ( T () represents the temperature correction factor; C d This is the flow correction factor; A ( x The area is the flow area, and its size depends on the displacement of the main valve core. x , which represents a linear relationship; ρ The density of the oil; P a , P b The pressure is the oil pressure at both ends of the main valve core of the flow control valve.

2. The pilot flow soft closed-loop master-stage amplified flow control method according to claim 1, characterized in that, The current calibration value I s Controlling the displacement of the pilot valve based on displacement-force feedback control, and determining the flow rate at the output of the flow control valve based on the displacement of the pilot valve, including: Current calibration value I s The proportional electromagnet in the displacement-force feedback control module of the flow control valve is input. When the proportional electromagnet operates, it adjusts the size of the throttle orifice in the displacement-force feedback control module, thereby adjusting the displacement of the pilot valve.

3. A pilot flow soft closed-loop master-stage amplified flow control system, characterized in that, include: The data acquisition module is used to acquire the target flow signal Q at the output of the flow control valve. s The pressure at the main valve inlet and outlet of the flow control valve and the temperature of the oil in the oil passage inside the main valve body are collected. The determination module is used to determine the target flow signal Q. s Determine the current signal I of the pilot valve used to control the flow control valve, determine the displacement of the pilot valve core of the flow control valve based on the displacement-force feedback control method according to the current signal I, determine the displacement of the main valve core of the flow control valve according to the displacement of the pilot valve core, and determine the flow area of ​​the main valve of the flow control valve according to the displacement of the main valve core. The first calculation module is used to calculate the actual flow signal Q at the output of the flow control valve based on the main valve's flow area, the pressure at the main valve's inlet and outlet, and the temperature of the oil in the oil passage inside the main valve body. f ; The second calculation module is used to process the target flow signal Q. s and actual flow signal Q f The input is processed by a proportional amplifier to obtain a comparison current signal ΔI. The current signal I and the comparison current signal ΔI are then summed to obtain the current calibration value I. s This includes: amplifying the target flow signal Q using a proportional amplifier. s and actual flow signal Q f The calibration process involves converting the calibrated signal into a current signal and outputting it to a current calibration device. The current calibration device then integrates the received current signal I with the comparison current signal ΔI output from the proportional amplifier to output the current calibration value I. s ; The control module is used to calibrate the current value I. s The displacement of the valve core of the pilot valve based on the displacement-force feedback control method is controlled, and the flow rate at the output end of the flow control valve is determined according to the displacement of the valve core. This also includes: the pressure signal and temperature signal of the flow control valve collected, as well as the calculated actual flow signal Q. f When the deviation from the corresponding parameter originally preset in the controller exceeds the preset value, a fault alarm is triggered; ;in, K ( T () represents the temperature correction factor; C d This is the flow correction factor; A ( x The area is the flow area, and its size depends on the displacement of the main valve core. x , which represents a linear relationship; ρ The density of the oil; P a , P b The pressure is the oil pressure at both ends of the main valve core of the flow control valve.

4. The pilot flow soft closed-loop master-stage amplified flow control system according to claim 3, characterized in that, The control module is used to set the current calibration value I. s The proportional electromagnet in the displacement-force feedback control module of the flow control valve is input. When the proportional electromagnet operates, it adjusts the size of the throttle orifice in the displacement-force feedback control module, thereby adjusting the displacement of the pilot valve.

5. A pilot-flow soft closed-loop main-stage amplification flow control valve, characterized in that, include: The valve body includes a valve body, a controller, a proportional amplifier, a current calibration device, and a high-precision fast calculator. The valve body is equipped with a main valve core assembly, a pilot valve core assembly, a temperature sensor, a pressure sensor, and a displacement-force feedback end cap assembly. The pressure sensor is installed at the inlet and outlet of the main oil passage of the flow control valve, and the temperature sensor is installed at the outlet of the main oil passage of the flow control valve. The signals collected by the temperature and pressure sensors are transmitted to a high-precision, high-speed calculator. Controller, used to determine the target flow rate signal Q s Determine the current signal I of the pilot valve used to control the flow control valve, determine the displacement of the pilot valve core of the flow control valve based on the displacement-force feedback control method according to the current signal I, determine the displacement of the main valve core assembly according to the displacement of the pilot valve core, and determine the main valve flow area of ​​the flow control valve according to the displacement of the main valve core. A high-precision, fast calculator is used to calculate the actual flow signal Q at the output of the flow control valve based on the main valve's flow area, the pressure at the main valve's inlet and outlet, and the temperature of the oil in the main valve body's internal oil passages. f ; A proportional amplifier is used to amplify the target flow signal Q. s and actual flow signal Q f The comparison process yields a comparison current signal ΔI, which is output to a current calibration device. The current calibration device integrates the calculated current signal I and the comparison current signal ΔI to obtain the current calibration value I. s This includes: amplifying the target flow signal Q using a proportional amplifier. s and actual flow signal Q f The calibration process involves converting the calibrated signal into a current signal and outputting it to a current calibration device. The current calibration device then integrates the received current signal I with the comparison current signal ΔI output from the proportional amplifier to output the current calibration value I. s ; The displacement-force feedback end cap assembly includes a proportional electromagnet, a displacement-force feedback end cap valve core, and a displacement-force feedback end cap; the proportional electromagnet is used to respond to a current calibration value I. s Then, it operates, moving the displacement-force feedback end cap valve core to the corresponding current calibration value I. s The position controls the size of the throttling orifice in the displacement-force feedback control end cover, and the throttling orifice in the displacement-force feedback control end cover is used to adjust the pressure in the control chamber of the displacement-force feedback end cover; The pilot valve core assembly is used to control the displacement of the main valve core in the main valve core assembly according to the pressure of the pilot oil, thereby controlling the output flow rate; The controller is used to process the pressure signal, temperature signal, and calculated actual flow signal Q from the acquired flow control valve. f When the deviation from the corresponding parameter originally preset in the controller exceeds the preset value, a fault alarm is triggered; ； in, K ( T () represents the temperature correction factor; C d This is the flow correction factor; A ( x The area is the flow area, and its size depends on the displacement of the main valve core. x , which represents a linear relationship; ρ The density of the oil; P a , P b The pressure is the oil pressure at both ends of the main valve core of the flow control valve.

6. The pilot flow soft closed-loop main stage amplification flow control valve according to claim 5, characterized in that, The main valve core of the main valve core assembly adopts a cone valve structure.

7. A hydraulic engineering machine, characterized in that, Includes the pilot flow soft closed-loop main stage amplification flow control valve as described in any one of claims 5-6.

Images