An electric servo precision regulating valve and its control method

Abstract

This invention relates to the field of fluid control technology, and in particular to an electric servo precision regulating valve and its control method. The valve includes a servo motor, a bell-shaped housing, a valve sleeve fixture, and a valve seat. The servo motor is fixedly mounted on the top of the bell-shaped housing, the valve sleeve fixture is fixedly connected to the bottom of the bell-shaped housing, and the top of the valve seat is fixedly mounted inside the valve sleeve fixture. The valve also includes: an inlet port located at the bottom of the valve seat; and a drain port located on the side of the valve seat, with the inlet port and drain port communicating with each other. This invention uses the movable connection between the lead screw and the valve stem, along with real-time monitoring of the offset pressure by multiple pressure sensors, to accurately detect the direction and degree of valve stem offset. Furthermore, it automatically distinguishes three different causes of offset—particulate matter jamming, structural offset, and fluid pulsation—based on the variation characteristics of the differential value, providing a basis for targeted treatment.

Description

Technical Field

[0001] This invention relates to the field of fluid control technology, and in particular to an electric servo precision regulating valve and its control method. Background Technology

[0002] The electrically controlled regulating valve receives a standard electrical signal and drives the valve core to continuously move through the actuator, changing the valve opening to precisely control fluid parameters. It requires an external power supply and a matching control system and is suitable for automated process industries.

[0003] Patent document CN121539652A discloses an electric servo regulating valve and its control method, including a servo motor, a precision planetary reducer, an electric cylinder, a valve frame, and a regulating valve body connected in sequence; the servo motor has a built-in absolute encoder; the electric cylinder integrates a ball screw transmission component; the regulating valve body includes a valve stem, a valve cover, and a valve body; the ball screw transmission component is connected to the precision planetary reducer and the valve stem respectively; when the precision planetary reducer rotates, it drives the valve stem to move linearly through the ball screw, thereby controlling the valve opening.

[0004] In existing electrically controlled control valves, the valve stem and lead screw are mostly rigidly connected. When the valve stem shifts due to particulate matter jamming, the deflection torque is directly transmitted to the lead screw and motor bearings. Fatigue wear of the lead screw thread and bearings can even lead to jamming or motor overload and burnout. At the same time, during use, the sealing surfaces of the valve stem and valve seat are easily worn due to particulate matter erosion or frequent opening and closing, resulting in increased leakage and affecting the accuracy of flow control. When the valve stem shifts, existing technology makes it difficult to monitor the direction and magnitude of the shift in real time, and it is impossible to distinguish whether the shift is caused by particulate matter jamming, structural wear, or fluid pulsation. This makes it impossible for operators to take targeted measures, and usually requires stopping the machine for disassembly and inspection, affecting the continuity of production. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by proposing an electric servo precision regulating valve and its control method.

[0006] To achieve the above objectives, the technical solution adopted by this invention is as follows: an electric servo precision regulating valve, comprising a servo motor, a bell-shaped cover, a valve sleeve fixture, and a valve seat. The servo motor is fixedly mounted on the top of the bell-shaped cover, the valve sleeve fixture is fixedly connected to the bottom of the bell-shaped cover, and the top of the valve seat is fixedly mounted inside the valve sleeve fixture. The valve seat also includes: Liquid inlet is located at the bottom of the valve seat; The drain hole is located on the side of the valve seat, and the inlet hole is connected to the drain hole. The valve stem is slidably connected inside the inlet hole. The valve stem has a closed position and an open position. When in the closed position, the valve stem blocks the communication between the inlet hole and the outlet hole. A connecting hole is located on the top of the valve seat and communicates with the liquid inlet hole. A lead screw is connected to the internal thread of the connecting hole. The transmission assembly is located inside the bell-shaped housing and is used for the transmission between the servo motor and the lead screw. The ball joint connection assembly includes a ball head located at the lower end of the lead screw and a ball socket fixedly connected to the upper end of the valve stem. The ball head is movably fitted in the ball socket, and a connecting rod is fixedly connected between the ball head and the lead screw. The pressure monitoring component includes multiple pressure sensors circumferentially positioned above the ball socket for real-time detection of contact pressure during offset. The controller is electrically connected to the servo motor and multiple pressure sensors. The controller is configured to determine the offset state of the valve stem based on the pressure signals output by the pressure sensors and control the action of the servo motor.

[0007] Preferably, the pressure monitoring component further includes: The outer ring is fixedly connected to the top of the ball socket; The inner ring is fixedly connected to the connecting rod and located inside the outer ring; Multiple sliding sleeves are fixedly inserted into the outer ring along the circumference. Multiple pressure sensors are fixedly installed inside the corresponding sliding sleeves. Each sliding sleeve has a movable plate and a limiting pin slidably connected inside. A first spring is fixedly connected between the movable plate and the limiting pin. A spherical protrusion is fixedly connected to the side of the movable plate away from the limiting pin. The spherical protrusion is in elastic contact with the corresponding pressure sensor. One end of the limiting pin is in elastic contact with the inner ring.

[0008] Preferably, the control logic of the controller and the pressure sensor is as follows: Offset detection: The output values ​​of multiple pressure sensors are collected in real time at a preset sampling period. Each pressure sensor is arranged circumferentially and corresponds to a different detection direction. The pressure values ​​collected in real time by each pressure sensor are subtracted from the pre-stored initial calibration values ​​to obtain the pressure deviation values ​​in each direction; Calculate the difference between the maximum and minimum values ​​of each pressure deviation, define this difference as the offset characteristic value, and define the sensor direction corresponding to the maximum pressure deviation value as the offset direction; Cause identification: When the offset characteristic value is greater than or equal to the pre-stored safety difference, the controller determines the cause of the offset based on the change characteristics of the offset characteristic value: If the offset characteristic value increases sharply within the first time window and then fluctuates violently, it is judged to be particulate matter stagnation. If the offset characteristic value increases monotonically and changes smoothly over multiple consecutive control cycles, it is judged as structural wear offset. If the offset characteristic value fluctuates periodically and the fluctuation frequency is consistent with the preset external vibration frequency, it is judged as fluid pulsation.

[0009] Preferably, when the controller determines that the offset is caused by particulate matter jamming, the control logic between the controller and the servo motor is as follows: The controller outputs high-frequency positive and negative pulse signals to the servo motor, driving the servo motor to reciprocate within a preset small angle range, which is converted into axial micro-vibration of the valve stem through the lead screw and ball joint connection assembly; During the vibration process, the controller continuously monitors the changes in the offset characteristic value; When the offset characteristic value drops below the safety tolerance, the controller stops outputting high-frequency positive and negative pulse signals, and the vibration ends. When the vibration duration exceeds the preset clearing time and the offset characteristic value still has not decreased below the safety difference, the controller outputs an alarm signal.

[0010] Preferably, when the controller determines that the offset is due to structural wear, the control logic between the controller and the servo motor is as follows: The controller records the current offset direction and degree, and stores them in memory; When the offset characteristic value exceeds the preset wear warning threshold, the controller outputs a maintenance warning signal.

[0011] Preferably, a first connecting ring and a second connecting ring are fixedly connected to the top end face of the liquid inlet and the top end face of the valve stem, respectively, and a second spring is fixedly connected between the first connecting ring and the second connecting ring.

[0012] Preferably, the transmission assembly includes: The mounting ring is fixedly connected to the inside of the bell-shaped cover. The inside of the mounting ring is rotatably connected to a rotating column, and the inside of the rotating column has a diamond-shaped through hole that runs along the axial direction. A diamond-shaped rod is fixedly connected to the top of the lead screw, and the upper end of the diamond-shaped rod is slidably inserted into the diamond-shaped through hole. The coupling is located inside the bell-shaped housing, and the output shaft of the servo motor is fixedly connected to the rotating column through the coupling.

[0013] Preferably, an inlet pipe is fixedly connected to the bottom of the valve seat, and the inlet pipe is connected to the inlet hole; A drain pipe is fixedly connected to the side of the valve seat. The drain pipe is connected to the drain hole. Both the inlet pipe and the drain pipe have connecting threads on their outer walls.

[0014] Preferably, the bottom end of the valve stem is provided with a guide slope, which is located at the bottom of the connection between the inlet hole and the outlet hole.

[0015] A control method for an electric servo precision regulating valve includes the following steps: Step 1: Collect the output values ​​of multiple pressure sensors in real time, calculate the deviation between the pressure value in each direction and the initial calibration value, take the difference between the maximum deviation and the minimum deviation as the offset feature value, and take the direction corresponding to the maximum deviation as the offset direction. Step 2: When the offset characteristic value is greater than or equal to the safety difference, determine the cause of the offset based on the change characteristics of the offset characteristic value: if it rises sharply and fluctuates violently, it is judged to be particulate matter stuck; if it increases monotonically and changes steadily, it is judged to be structural wear offset; if it fluctuates periodically, it is judged to be fluid pulsation. Step 3: Execute corresponding actions based on the judgment results: When particulate matter is stuck, generate high-frequency micro-amplitude vibration until the offset characteristic value returns to normal; when structural wear offsets, record data and output warning; when fluid pulsation occurs, only record diagnostic data.

[0016] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention uses the movable connection between the lead screw and the valve stem and multiple pressure sensors to monitor the offset pressure in real time, so as to accurately detect the offset direction and degree of the valve stem offset. It also automatically distinguishes three different offset causes, namely particulate matter jamming, structural offset and fluid pulsation, by the change characteristics of the difference, so as to provide a basis for targeted treatment.

[0017] 2. When the controller determines that the offset is caused by particulate matter jamming, the controller drives the servo motor to perform a small range of reciprocating rotation, which is converted into axial vibration of the valve stem. When the particulate matter jammed in the gap is displaced under the action of vibration and shaken off from the jammed position, the offset characteristic value drops below the safety tolerance, and the controller immediately stops outputting high-frequency positive and negative pulse signals. 3. The controller records and stores the current offset characteristic value, offset direction, and occurrence time in the memory. When the offset characteristic value is less than the wear warning threshold, the controller only records the data and does not output a warning signal. When the offset characteristic value is greater than or equal to the wear warning threshold, it indicates that the wear has affected the normal use of the valve body, and the controller outputs a maintenance warning signal. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a cross-sectional structural diagram of the present invention; Figure 3 For the present invention Figure 2 Enlarged schematic diagram of the structure at point A in the diagram; Figure 4 For the present invention Figure 2 Enlarged schematic diagram of the structure at point B in the diagram; Figure 5 For the present invention Figure 4 A magnified schematic diagram of the structure at point C.

[0019] In the diagram: 1. Servo motor; 2. Bell-shaped cover; 3. Valve sleeve fixture; 4. Valve seat; 5. Inlet port; 6. Drain port; 7. Valve stem; 8. Connecting hole; 9. Lead screw; 10. Ball head; 11. Ball socket; 12. Connecting rod; 13. Pressure sensor; 14. Outer ring; 15. Inner ring; 16. Sliding sleeve; 17. Movable plate; 18. Limit pin; 19. First spring; 20. Spherical protrusion; 22. First connecting ring; 23. Second connecting ring; 24. Second spring; 25. Mounting ring; 26. Rotating column; 27. Diamond-shaped through hole; 28. Diamond-shaped rod; 29. ​​Coupling; 30. Inlet pipe; 31. Drain pipe. Detailed Implementation

[0020] The following description is intended to disclose the invention and enable those skilled in the art to implement it. The preferred embodiments described below are merely examples, and other obvious variations will occur to those skilled in the art.

[0021] like Figures 1 to 5 The electric servo precision regulating valve shown includes a servo motor 1, a bell-shaped housing 2, a valve sleeve fixture 3, and a valve seat 4. The servo motor 1 is fixedly mounted on the top of the bell-shaped housing 2, the valve sleeve fixture 3 is fixedly connected to the bottom of the bell-shaped housing 2, and the top of the valve seat 4 is fixedly mounted inside the valve sleeve fixture 3. It also includes: Liquid inlet 5 is located at the bottom of valve seat 4; Drain hole 6 is located on the side of valve seat 4, and inlet hole 5 is connected to drain hole 6. The valve stem 7 is slidably connected inside the liquid inlet 5. The valve stem 7 has a closed position and an open position. When in the closed position, the valve stem 7 blocks the communication between the liquid inlet 5 and the liquid outlet 6. Connection hole 8 is located on the top of valve seat 4 and communicates with liquid inlet hole 5. A lead screw 9 is threaded inside connection hole 8. A transmission assembly is located inside the bell-shaped housing 2 and is used for transmission between the servo motor 1 and the lead screw 9. The ball joint assembly includes a ball head 10 located at the lower end of the lead screw 9 and a ball socket 11 fixedly connected to the upper end of the valve stem 7 (e.g., Figure 4 As shown), the ball head 10 is movably fitted in the ball socket 11, and a connecting rod 12 is fixedly connected between the ball head 10 and the lead screw 9; The pressure monitoring assembly includes multiple pressure sensors 13 circumferentially arranged above the ball socket 11 (e.g. Figure 5 (As shown), used to detect contact pressure during offset in real time; The controller is electrically connected to the servo motor 1 and multiple pressure sensors 13. The controller is configured to determine the offset state of the valve stem 7 based on the pressure signals output by the pressure sensors 13 and control the action of the servo motor 1.

[0022] Servo motor 1 receives an external control signal and starts to rotate. The output torque of servo motor 1 is transmitted to lead screw 9 through the transmission component, driving lead screw 9 to rotate in connection hole 8. Since lead screw 9 and connection hole 8 are connected by a thread, the rotational motion of lead screw 9 is converted into axial linear motion. Lead screw 9 drives valve stem 7 to slide axially in inlet hole 5 through ball joint connection component. When the valve stem 7 is in the closed position, the outer wall of the valve stem 7 blocks the communication path between the inlet hole 5 and the outlet hole 6, and the medium cannot flow from the inlet hole 5 to the outlet hole 6, so the valve is in the closed state; when the servo motor 1 drives the valve stem 7 to move upward to the open position, a gap appears between the valve stem 7 and the inner wall of the inlet hole 5, and the inlet hole 5 and the outlet hole 6 are connected. The medium flows in from the inlet hole 5, passes through the gap between the valve stem 7 and the inlet hole 5, and flows out from the outlet hole 6, so the valve is in the open state; By controlling the rotation angle and direction of the servo motor 1, the axial displacement of the valve stem 7 can be precisely controlled, thereby adjusting the flow cross-sectional area of ​​the inlet hole 5 and the outlet hole 6, and achieving precise adjustment of the medium flow rate. The lead screw 9 and the valve stem 7 are connected by a ball joint assembly. The ball head 10 at the lower end of the lead screw 9 is movably fitted in the ball socket 11 at the upper end of the valve stem 7. The ball head 10 can rotate freely in the ball socket 11. Multiple pressure sensors 13 are evenly distributed around the ball socket 11 and monitor the contact pressure in real time when the displacement occurs. The controller collects the output values ​​of multiple pressure sensors 13 in real time, takes the direction of the pressure sensor 13 with the largest pressure value as the offset direction of the valve stem 7, and calculates the difference between the maximum pressure value and the minimum pressure value. The larger the difference, the more serious the offset; the smaller the difference, the higher the coaxiality between the valve stem 7 and the liquid inlet 5. After the valve is put into use for the first time or after maintenance and calibration, the controller collects and stores the output values ​​of each pressure sensor 13 when the valve stem 7 and the inlet port 5 are in a good coaxial state (i.e., the offset characteristic value is less than the normal fluctuation threshold) as the reference value. During normal operation, the controller calculates the difference between the current output value of each pressure sensor 13 and the corresponding reference value, and takes the difference between the maximum and minimum values ​​of the differences in four directions. This difference is defined as the offset characteristic value. When the valve stem 7 and the inlet port 5 are in a good coaxial state, this offset characteristic value is less than the normal fluctuation threshold, which is pre-calibrated according to the valve specifications. The controller also has a pre-stored safety margin, which is used to determine whether the valve stem 7 has experienced a significant deviation that requires intervention. The safety margin is greater than the normal fluctuation threshold, and its value is determined based on the yield strength of the valve stem 7 material and the valve's rated pressure. The controller automatically determines the specific cause of valve stem 7 offset based on the changes in the offset characteristic value: Determining particulate matter congestion: When the offset characteristic value rises sharply from below the normal fluctuation threshold to above the safety difference in a short period of time, and the increase is greater than half of the safety difference, and the fluctuation range of the offset characteristic value is greater than one-third of the increase in a subsequent period of time, the controller determines that particulate matter is stuck. The physical mechanism is as follows: when particulate matter enters the gap between valve stem 7 and inlet hole 5, it generates instantaneous impact force in a certain direction, resulting in a sudden increase in the offset characteristic value; the particulate matter may be displaced or rolled under the scouring of the medium, resulting in violent fluctuations in the offset characteristic value.

[0023] Determining structural wear offset: When the offset characteristic value shows a monotonically increasing trend over multiple consecutive control cycles, and the increment in each cycle is less than one-tenth of the safety difference, and the fluctuation range of the offset characteristic value is less than one-tenth of the safety difference, the controller determines it as structural wear offset. The physical mechanism is as follows: due to long-term wear, the center line of valve stem 7 slowly shifts between the surface of valve stem 7 and the inner wall of inlet hole 5, resulting in a gradual change in pressure distribution without sudden fluctuations. Determining fluid pulsation: When the offset characteristic value exhibits periodic fluctuations, the frequency of which is basically consistent with the preset pump or pipeline vibration frequency, and the peak value of the offset characteristic value is always lower than the safety difference, the controller determines it as fluid pulsation.

[0024] The physical mechanism is as follows: the pulsation of the upstream pump or the vibration of the pipeline is transmitted to the valve stem 7 through the medium, generating a periodic lateral force, but not to the extent that intervention is required; The normal fluctuation threshold is a boundary value used to determine whether the valve stem is in a good coaxial state; this threshold is pre-calibrated according to the valve specifications (nominal diameter, nominal pressure) and the range of the pressure sensor, and is preferably 0.5% to 2% of the full scale of the pressure sensor 13; The specific calibration method is as follows: Under normal valve operating conditions (rated flow rate, rated pressure), run continuously for no less than 30 minutes, collect the output values ​​of each pressure sensor 13 and calculate the offset characteristic value. Take the maximum value of the offset characteristic value within this time period and multiply it by a safety factor of 1.2 to 1.5 times as the normal fluctuation threshold. This threshold is used to distinguish between normal operating fluctuations and abnormal offsets of the valve stem 7. When the offset characteristic value is less than this threshold, the controller determines that the valve stem is in a good coaxial state and does not perform any intervention action. The safety difference is a critical value used to determine whether the valve stem 7 has experienced a significant deviation that requires intervention; this difference is greater than the normal fluctuation threshold, and its value is determined based on the yield strength of the valve stem 7 material and the rated pressure of the valve. The specific calculation method is as follows: First, based on the yield strength of valve stem 7 material... and valve stem dangerous cross-sectional area Calculate the allowable axial load on the valve stem. (in For safety factors, a value of 1.5 to 3.0 is generally used; then, based on the lever arm length of the lateral force acting on valve stem 7... The allowable load is converted into allowable lateral force; finally, the allowable lateral force is converted into the corresponding pressure difference value through the force-pressure calibration curve of pressure sensor 13, which is the safety difference value. This invention uses the movable connection between the lead screw 9 and the valve stem 7 and the real-time monitoring of the offset pressure by multiple pressure sensors 13 to accurately detect the offset direction and degree of the valve stem 7. It also automatically distinguishes three different offset causes—particulate matter jamming, structural offset, and fluid pulsation—by the change characteristics of the difference, providing a basis for targeted treatment.

[0025] As a further embodiment of the present invention, the pressure monitoring component also includes: The outer ring 14 is fixedly connected to the top of the ball socket 11; Inner ring 15 is fixedly connected to connecting rod 12 and located inside outer ring 14; Multiple sliding sleeves 16 are fixedly inserted into the outer ring 14 circumferentially. Multiple pressure sensors 13 are fixedly installed inside the corresponding sliding sleeves 16. Each sliding sleeve 16 is slidably connected to a movable plate 17 and a limiting pin 18. A first spring 19 is fixedly connected between the movable plate 17 and the limiting pin 18. A spherical protrusion 20 is fixedly connected to the side of the movable plate 17 away from the limiting pin 18. The spherical protrusion 20 is in elastic contact with the corresponding pressure sensor 13. One end of the limiting pin 18 is in elastic contact with the inner ring 15.

[0026] One end of the limiting pin 18 always abuts against the outer side of the inner ring 15. When the inner ring 15 moves, it pushes the limiting pin 18, and the other end of the limiting pin 18 compresses the first spring 19. The elastic force of the first spring 19 is transmitted to the pressure sensor 13 through the movable plate 17 and the spherical protrusion 20, so that the pressure sensor 13 generates a pressure reading corresponding to the compression amount of the first spring 19. When the lead screw 9 deviates from the valve stem 7, the ball head 10 deflects or radially displaces relative to the ball socket 11. This causes a relative misalignment between the outer ring 14, fixedly connected to the top of the ball socket 11, and the inner ring 15, fixedly connected to the connecting rod 12. This increases the contact force between the inner ring 15 and the corresponding limiting pin 18, further compressing the first spring 19 in this direction, and increasing the reading of the pressure sensor 13. Conversely, the contact force between the limiting pin 18 and the inner ring 15 decreases in the opposite direction, causing the first spring 19 to extend and the reading of the pressure sensor 13 to decrease. The controller can determine the direction and degree of deviation of the valve stem 7 by comparing the changes in the readings of each pressure sensor 13.

[0027] As a further embodiment of the present invention, the control logic of the controller and the pressure sensor 13 is as follows: Offset detection: The output values ​​of multiple pressure sensors 13 are collected in real time at a preset sampling period. Each pressure sensor 13 is arranged circumferentially and corresponds to a different detection direction. Subtract the pressure values ​​collected in real time by each pressure sensor 13 from the pre-stored initial calibration values ​​to obtain the pressure deviation values ​​in each direction; Calculate the difference between the maximum and minimum values ​​of each pressure deviation, define this difference as the offset characteristic value, and define the sensor direction corresponding to the maximum pressure deviation value as the offset direction; Cause identification: When the offset characteristic value is greater than or equal to the pre-stored safety difference, the controller determines the cause of the offset based on the change characteristics of the offset characteristic value: If the offset characteristic value increases sharply within the first time window and then fluctuates violently, it is judged to be particulate matter stagnation. If the offset characteristic value increases monotonically and changes smoothly over multiple consecutive control cycles, it is judged as structural wear offset. If the offset characteristic value fluctuates periodically and the fluctuation frequency is consistent with the preset external vibration frequency, it is judged as fluid pulsation.

[0028] The first time window is a preset time length used to determine whether the offset characteristic value changes drastically in a short period of time. According to the dynamic response characteristics of the valve, the value range of the first time window is preferably 0.5 to 2 seconds. Within this time window, the controller continuously collects the offset characteristic value at a preset sampling period (e.g., 10ms). If the offset characteristic value rises from below the normal fluctuation threshold to exceed the safety difference, and the increase is greater than half of the safety difference, it is determined to be a drastic increase. The time window is set based on the following: particulate matter jamming is a sudden fault, and the time for particulate matter to enter the gap between valve stem 7 and inlet hole 5 is usually in the range of milliseconds to seconds; too short a time window (such as less than 0.5 seconds) may cause misjudgment due to signal noise, while too long a time window (such as more than 2 seconds) may misjudge a slowly developing structural displacement as particulate matter jamming. The initial calibration value refers to the reference pressure value obtained by statically calibrating each pressure sensor before the valve is put into use for the first time or after maintenance and calibration, with the valve stem 7 in a good coaxial state; The calibration method is as follows: First, adjust the coaxiality of the valve stem 7 and the inlet hole 5 (the coaxiality error between the valve stem and the inlet hole can be confirmed by a dial indicator or coaxiality tester to be no greater than 0.03mm). Then, in this state, collect the output values ​​of each pressure sensor 13 and continuously collect no less than 10 sampling cycles. Take the arithmetic mean as the initial calibration value of the pressure sensor 13. During the calibration process, there is no medium flow inside the valve, and the servo motor 1 is in a power-off and locked state to eliminate the interference of fluid pulsation and servo motor 1 vibration on the calibration results. After calibration, the initial calibration values ​​of each pressure sensor 13 are stored in the controller's memory; during normal operation, the real-time acquired values ​​are subtracted from the initial calibration values ​​to obtain the pressure deviation values ​​in each direction; The preset external vibration frequency refers to the characteristic vibration frequency of the upstream pump or pipeline connected to the valve; this frequency is obtained through the following method: (1) During the valve installation and commissioning stage, the vibration spectrum of the upstream pump and pipeline is measured by vibration sensor, and the main frequency component is extracted as the preset external vibration frequency. (2) If on-site measurement is not possible, the vibration frequency can be calculated based on the pump speed. ,in The pump speed (r / min) is the rotational speed of the pump. This refers to the number of blades or plungers. The controller compares the fluctuation spectrum of the offset characteristic value with the preset external vibration frequency. When the frequency deviation between the two is within ±5%, it is determined to be an offset caused by fluid pulsation.

[0029] As a further embodiment of the present invention, when the controller determines that the cause of the offset is particulate matter jamming, the control logic of the controller and servo motor 1 is as follows: The controller outputs high-frequency positive and negative pulse signals to the servo motor 1, driving the servo motor 1 to reciprocate within a preset small angle range, which is converted into axial micro-vibration of the valve stem 7 through the lead screw 9 and ball joint connection assembly; During the vibration process, the controller continuously monitors the changes in the offset characteristic value; When the offset characteristic value drops below the safety tolerance, the controller stops outputting high-frequency positive and negative pulse signals, and the vibration ends. When the vibration duration exceeds the preset clearing time and the offset characteristic value still has not decreased below the safety difference, the controller outputs an alarm signal.

[0030] The preset small angle range refers to the angle limit value for driving the servo motor 1 to reciprocate when the controller determines that particulate matter is stuck; this angle range is preferably ±3% to ±8% of the rated rotation angle of the servo motor 1. The setting principle for this angle range is as follows: if the angle is too small (e.g., less than ±3%), it will not be able to generate enough vibration amplitude to shake off stuck particles; if the angle is too large (e.g., greater than ±8%), it may cause the valve stem 7 to move beyond the allowable range, affecting the normal adjustment function of the valve or causing additional wear between the valve stem 7 and the inner wall of the inlet hole 5; within this angle range, the reciprocating motion of the servo motor 1 is converted into axial micro-vibration of the valve stem 7 through the lead screw 9 and the ball joint connection assembly, and the amplitude is preferably 0.05 to 0.2 mm.

[0031] When the controller determines that the offset is caused by particulate matter jamming, the controller drives the servo motor 1 to perform a small range of reciprocating rotation, which is converted into axial vibration of the valve stem 7. When the particulate matter jammed in the gap is displaced under the action of vibration and shaken off from the jammed position, the offset characteristic value drops below the safety tolerance, and the controller immediately stops outputting high-frequency positive and negative pulse signals. The controller has a preset clearing time threshold. The controller starts timing from the start of vibration. If the offset characteristic value fails to drop below the safety difference within the clearing time threshold, it indicates that the particulate matter cannot be eliminated by vibration. The controller then stops outputting the vibration signal and outputs an alarm signal. The clearing time threshold refers to the maximum allowable duration for which the controller attempts to clear the stuck particles using high-frequency micro-amplitude vibration after determining that the particles are stuck. This threshold is preferably 3 to 10 seconds. The settings are based on the following: If the stuck particles can be cleared by vibration, a significant decrease in the offset characteristic value can usually be observed within 3 seconds; if the offset characteristic value does not improve significantly after more than 10 seconds of vibration, it indicates that the particles have become embedded in the gap between the valve stem 7 and the inlet hole 5 or the particles are too large to be shaken off by vibration. Continuing to vibrate will not only be ineffective, but may also aggravate the wear of the valve stem 7 and the inlet hole 5; when the vibration duration exceeds the clearing time threshold, the controller stops vibrating and outputs an alarm signal.

[0032] As a further embodiment of the present invention, when the controller determines that the offset is due to structural wear, the control logic between the controller and the servo motor 1 is as follows: The controller records the current offset direction and degree, and stores them in memory; When the offset characteristic value exceeds the preset wear warning threshold, the controller outputs a maintenance warning signal.

[0033] When the controller determines that there is structural wear deviation, it does not output an active correction command because structural wear is an irreversible mechanical damage that cannot be repaired by instantaneous action. The controller records and stores the current deviation characteristic value, deviation direction, and occurrence time in its memory. When the deviation characteristic value is less than the wear warning threshold, the controller only records the data and does not output a warning signal. When the deviation characteristic value is greater than or equal to the wear warning threshold, it indicates that the wear has affected the normal use of the valve body, and the controller outputs a maintenance warning signal.

[0034] The wear warning threshold is a critical value used to determine whether the degree of structural wear has reached the point where maintenance intervention is required; this threshold is greater than the normal fluctuation threshold but less than the safety difference, preferably 60% to 80% of the safety difference; When the offset characteristic value continues to increase and reaches the wear warning threshold, it indicates that the wear between the valve stem 7 and the inner wall of the inlet hole 5 has accumulated to the point that it affects the normal service life of the valve, but has not yet reached the point that it immediately affects the safe operation of the valve. At this time, the controller outputs a maintenance warning signal to prompt the operator to arrange a shutdown for maintenance in the near future, rather than an immediate emergency shutdown.

[0035] As a further embodiment of the present invention, a first connecting ring 22 and a second connecting ring 23 are fixedly connected to the top end face of the liquid inlet hole 5 and the top end face of the valve stem 7, respectively, and a second spring 24 is fixedly connected between the first connecting ring 22 and the second connecting ring 23.

[0036] The elastic extension of the second spring 24 applies a downward elastic force to the valve stem 7. This elastic force is transmitted to the lead screw 9 through the ball joint connection assembly, so that the threaded pair between the lead screw 9 and the connecting hole 8 is kept in close contact, thereby eliminating the axial clearance between the lead screw 9 and the connecting hole 8 and improving the positioning accuracy when the lead screw 9 drives the valve stem 7 to move axially.

[0037] As a further embodiment of the present invention, the transmission assembly includes: Mounting ring 25 is fixedly connected to the inside of bell-shaped cover 2. Rotating column 26 is rotatably connected inside mounting ring 25. A diamond-shaped through hole 27 is opened inside rotating column 26 along the axial direction. The rhombus-shaped rod 28 is fixedly connected to the top of the lead screw 9, and the upper end of the rhombus-shaped rod 28 is slidably inserted into the rhombus-shaped through hole 27. The coupling 29 is located inside the bell-shaped housing 2, and the output shaft of the servo motor 1 is fixedly connected to the rotating column 26 through the coupling 29.

[0038] The output shaft of the servo motor 1 is fixedly connected to the rotating column 26 via the coupling 29, driving the rotating column 26 to rotate within the mounting ring 25. The rotating column 26 has an axially penetrating diamond-shaped through hole 27, and the diamond-shaped rod 28 at the top of the lead screw 9 is slidably inserted into the diamond-shaped through hole 27. Since both the diamond-shaped rod 28 and the diamond-shaped through hole 27 are non-circular cross sections, they cannot rotate relative to each other. Therefore, the rotational torque of the rotating column 26 is transmitted to the diamond-shaped rod 28 through the inner wall of the diamond-shaped through hole 27, driving the lead screw 9 to rotate synchronously.

[0039] Meanwhile, the diamond rod 28 and the diamond through hole 27 are clearance fit, allowing the diamond rod 28 to slide freely in the diamond through hole 27 along the axis. When the lead screw 9 rotates, due to the threaded fit between the lead screw 9 and the connecting hole 8, the lead screw 9 will generate axial displacement. At this time, the diamond rod 28 slides axially relative to the rotating column 26, adaptively compensating for the axial movement of the lead screw 9.

[0040] As a further embodiment of the present invention, a liquid inlet pipe 30 is fixedly connected to the bottom of the valve seat 4, and the liquid inlet pipe 30 is connected to the liquid inlet hole 5. A drain pipe 31 is fixedly connected to the side of the valve seat 4. The drain pipe 31 is connected to the drain hole 6. The outer walls of the inlet pipe 30 and the drain pipe 31 are both provided with connecting threads.

[0041] As a further embodiment of the present invention, a guide slope is provided at the bottom end of the valve stem 7, and the guide slope is located at the bottom of the connection between the liquid inlet hole 5 and the liquid outlet hole 6.

[0042] When the valve stem 7 moves upward from the closed position, the medium flows in through the inlet hole 5. The guide slope at the bottom of the valve stem 7 gradually changes the flow area of ​​the medium, thereby improving the accuracy of flow control.

[0043] A control method for an electric servo precision regulating valve includes the following steps: Step 1: Collect the output values ​​of multiple pressure sensors 13 in real time, calculate the deviation between the pressure value in each direction and the initial calibration value, take the difference between the maximum deviation and the minimum deviation as the offset feature value, and take the direction corresponding to the maximum deviation as the offset direction. Step 2: When the offset characteristic value is greater than or equal to the safety difference, determine the cause of the offset based on the change characteristics of the offset characteristic value: if it rises sharply and fluctuates violently, it is judged to be particulate matter stuck; if it increases monotonically and changes steadily, it is judged to be structural wear offset; if it fluctuates periodically, it is judged to be fluid pulsation. Step 3: Execute corresponding actions based on the judgment results: When particulate matter is stuck, generate high-frequency micro-amplitude vibration until the offset characteristic value returns to normal; when structural wear offsets, record data and output warning; when fluid pulsation occurs, only record diagnostic data.

[0044] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claims. The scope of protection claimed by the appended claims and their equivalents is defined.

Claims

1. An electric servo precision regulating valve, comprising a servo motor, a bell-shaped housing, a valve sleeve fixture, and a valve seat, wherein the servo motor is fixedly mounted on the top of the bell-shaped housing, the valve sleeve fixture is fixedly connected to the bottom of the bell-shaped housing, and the top of the valve seat is fixedly mounted inside the valve sleeve fixture, characterized in that, Also includes: Liquid inlet is located at the bottom of the valve seat; The drain hole is located on the side of the valve seat, and the inlet hole is connected to the drain hole. The valve stem is slidably connected inside the inlet hole. The valve stem has a closed position and an open position. When in the closed position, the valve stem blocks the communication between the inlet hole and the outlet hole. A connecting hole is located on the top of the valve seat and communicates with the liquid inlet hole. A lead screw is connected to the internal thread of the connecting hole. The transmission assembly is located inside the bell-shaped housing and is used for the transmission between the servo motor and the lead screw. The ball joint connection assembly includes a ball head located at the lower end of the lead screw and a ball socket fixedly connected to the upper end of the valve stem. The ball head is movably fitted in the ball socket, and a connecting rod is fixedly connected between the ball head and the lead screw. The pressure monitoring component includes multiple pressure sensors circumferentially positioned above the ball socket for real-time detection of contact pressure during offset. The controller is electrically connected to the servo motor and multiple pressure sensors. The controller is configured to determine the offset state of the valve stem based on the pressure signals output by the pressure sensors and control the action of the servo motor.

2. The electric servo precision regulating valve according to claim 1, characterized in that, The pressure monitoring component also includes: The outer ring is fixedly connected to the top of the ball socket; The inner ring is fixedly connected to the connecting rod and located inside the outer ring; Multiple sliding sleeves are fixedly inserted into the outer ring along the circumference. Multiple pressure sensors are fixedly installed inside the corresponding sliding sleeves. Each sliding sleeve has a movable plate and a limiting pin slidably connected inside. A first spring is fixedly connected between the movable plate and the limiting pin. A spherical protrusion is fixedly connected to the side of the movable plate away from the limiting pin. The spherical protrusion is in elastic contact with the corresponding pressure sensor. One end of the limiting pin is in elastic contact with the inner ring.

3. The electric servo precision regulating valve according to claim 2, characterized in that, The control logic of the controller and pressure sensor is as follows: Offset detection: The output values ​​of multiple pressure sensors are collected in real time at a preset sampling period. Each pressure sensor is arranged circumferentially and corresponds to a different detection direction. The pressure values ​​collected in real time by each pressure sensor are subtracted from the pre-stored initial calibration values ​​to obtain the pressure deviation values ​​in each direction; Calculate the difference between the maximum and minimum values ​​of each pressure deviation, define this difference as the offset characteristic value, and define the sensor direction corresponding to the maximum pressure deviation value as the offset direction; Cause identification: When the offset characteristic value is greater than or equal to the pre-stored safety difference, the controller determines the cause of the offset based on the change characteristics of the offset characteristic value: If the offset characteristic value increases sharply within the first time window and then fluctuates violently, it is judged to be particulate matter stagnation. If the offset characteristic value increases monotonically and changes smoothly over multiple consecutive control cycles, it is judged as structural wear offset. If the offset characteristic value fluctuates periodically and the fluctuation frequency is consistent with the preset external vibration frequency, it is judged as fluid pulsation.

4. The electric servo precision regulating valve according to claim 3, characterized in that, When the controller determines that the offset is caused by particulate matter jamming, the control logic of the controller and servo motor is as follows: The controller outputs high-frequency positive and negative pulse signals to the servo motor, driving the servo motor to reciprocate within a preset small angle range, which is converted into axial micro-vibration of the valve stem through the lead screw and ball joint connection assembly; During the vibration process, the controller continuously monitors the changes in the offset characteristic value; When the offset characteristic value drops below the safety tolerance, the controller stops outputting high-frequency positive and negative pulse signals, and the vibration ends. When the vibration duration exceeds the preset clearing time and the offset characteristic value still has not decreased below the safety difference, the controller outputs an alarm signal.

5. The electric servo precision regulating valve according to claim 3, characterized in that, When the controller determines that the offset is due to structural wear, the control logic between the controller and the servo motor is as follows: The controller records the current offset direction and degree, and stores them in memory; When the offset characteristic value exceeds the preset wear warning threshold, the controller outputs a maintenance warning signal.

6. The electric servo precision regulating valve according to claim 1, characterized in that, A first connecting ring and a second connecting ring are fixedly connected to the top end face of the liquid inlet and the top end face of the valve stem, respectively, and a second spring is fixedly connected between the first connecting ring and the second connecting ring.

7. The electric servo precision regulating valve according to claim 1, characterized in that, The transmission components include: The mounting ring is fixedly connected inside the bell-shaped cover. The mounting ring is rotatably connected to a rotating column inside, and the rotating column has a diamond-shaped through hole that runs through the axis. A diamond-shaped rod is fixedly connected to the top of the lead screw, and the upper end of the diamond-shaped rod is slidably inserted into the diamond-shaped through hole. The coupling is located inside the bell-shaped housing, and the output shaft of the servo motor is fixedly connected to the rotating column through the coupling.

8. The electric servo precision regulating valve according to claim 1, characterized in that, A liquid inlet pipe is fixedly connected to the bottom of the valve seat, and the liquid inlet pipe is connected to the liquid inlet hole; A drain pipe is fixedly connected to the side of the valve seat. The drain pipe is connected to the drain hole. Both the inlet pipe and the drain pipe have connecting threads on their outer walls.

9. The electric servo precision regulating valve according to claim 1, characterized in that, The bottom end of the valve stem is provided with a guide slope, which is located at the bottom of the connection between the inlet and outlet holes.

10. A control method for an electric servo precision regulating valve, applicable to the electric servo precision regulating valve according to any one of claims 1-9, characterized in that, Includes the following steps: Step 1: Collect the output values ​​of multiple pressure sensors in real time, calculate the deviation between the pressure value in each direction and the initial calibration value, take the difference between the maximum deviation and the minimum deviation as the offset feature value, and take the direction corresponding to the maximum deviation as the offset direction. Step 2: When the offset characteristic value is greater than or equal to the safety difference, determine the cause of the offset based on the change characteristics of the offset characteristic value: if it rises sharply and fluctuates violently, it is judged to be particulate matter stuck; if it increases monotonically and changes steadily, it is judged to be structural wear offset; if it fluctuates periodically, it is judged to be fluid pulsation. Step 3: Execute corresponding actions based on the judgment results: When particulate matter is stuck, generate high-frequency micro-amplitude vibration until the offset characteristic value returns to normal; when structural wear offsets, record data and output warning; when fluid pulsation occurs, only record diagnostic data.

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