A pneumatic angle seat valve

Abstract

This utility model discloses a pneumatic angle seat valve, belonging to the technical field of angle seat valves. It solves the problems of internal air leakage caused by long-term friction and wear of the piston sealing ring in the actuator cylinder of a pneumatic angle seat valve, resulting in decreased sealing performance, difficulty in establishing air pressure in double-acting cylinders, and reduced compression efficiency in single-acting cylinders. Ultimately, this leads to weak valve opening and closing, slow action, or even failure, causing slow response, loss of accuracy, and wasted air. The valve includes a valve body, a valve cover fixedly connected to the valve body, a connecting pipe fixedly connected to the valve cover and communicating with the valve body, a cylinder body fixedly connected to the upper end of the connecting pipe and communicating with it, and a cylinder cover fixedly connected to the cylinder body. This utility model dynamically monitors the air source flow rate in the pneumatic angle seat valve's inlet pipeline, extracts peak flow rate and action time characteristics, and compares them with preset normal benchmark values ​​in real time. When both insufficient peak flow rate and action timeout are detected simultaneously and confirmed with a delay, an alarm is triggered, thereby diagnosing the internal air leakage fault caused by piston sealing ring wear.

Description

Technical Field

[0001] This utility model relates to the field of angle seat valve technology, and in particular to a pneumatic angle seat valve. Background Technology

[0002] A pneumatic angle seat valve is a type of angle seat control valve driven by a pneumatic actuator (such as a cylinder). The valve body has an angle seat design, ensuring unobstructed flow and low flow resistance. It offers rapid on / off response, quickly controlling the flow of gases, liquids, and other fluids, making it suitable for high-flow-rate applications. Most are made of stainless steel, offering strong corrosion resistance; some are sanitary grade, suitable for the food, pharmaceutical, and chemical industries. It is easy to operate, highly reliable, and commonly used for controlling fluid flow. Its compact structure and wear resistance make it widely applicable in scenarios requiring efficient fluid control.

[0003] During the use of pneumatic angle seat valves, the piston sealing ring inside the actuator cylinder rubs and wears against the cylinder wall under long-term reciprocating motion. Poor compressed air quality or insufficient lubrication will accelerate this process, resulting in a decrease in the sealing performance of the piston sealing ring and causing a difficult-to-detect internal air leakage problem.

[0004] This problem causes compressed air to leak from one chamber to the other in a double-acting cylinder, preventing effective pressure build-up. In a single-acting cylinder, it reduces the compression efficiency of the spring. Ultimately, this manifests as weak valve opening and closing, slow operation, or even complete failure. The consequences include reduced valve response speed, loss of control precision, and continuous consumption of additional compressed air, resulting in energy waste.

[0005] Therefore, a pneumatic angle seat valve is proposed to solve or alleviate the above problems. Utility Model Content

[0006] The purpose of this utility model is to address the shortcomings of existing technologies by proposing a pneumatic angle seat valve.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A pneumatic angle seat valve includes a valve body, a valve cover fixedly connected to the valve body, a connecting pipe fixedly connected to the valve cover and communicating with the valve body, a cylinder body fixedly connected to and communicating with the upper end of the connecting pipe, a cylinder cover fixedly connected to the cylinder body, a piston slidably connected to the cylinder body, a valve stem fixedly connected to the piston and passing through the connecting pipe to the valve body, and a valve core fixedly connected to the lower end of the valve stem and located in the valve body. A return spring is provided in the cylinder body to abut against the piston and the inner top surface of the cylinder cover. The piston divides the cylinder body into an inlet chamber and an outlet chamber. The cylinder body has an inlet port communicating with the inlet chamber and an outlet port communicating with the outlet chamber. The inlet port is connected to an air compressor via an inlet pipe. A flow sensor is connected to the inlet pipe, and the flow sensor is electrically connected to an internal leakage fault detection circuit.

[0009] Preferably, the internal leakage fault detection circuit includes a signal conditioning module, a feature extraction module, a dynamic reference module, a logic comparison module, and a delay confirmation and alarm locking module;

[0010] The input terminal of the signal conditioning module is connected to the signal output terminal of the flow sensor. The dynamic reference module is used to provide a reference voltage signal. The input terminal of the feature extraction module is connected to the output terminal of the signal conditioning module. The first input terminal group of the logic comparison module is connected to the output terminal of the feature extraction module. The second input terminal group of the logic comparison module is connected to the output terminal of the dynamic reference module. The input terminal of the delay confirmation and alarm lockout module is connected to the output terminal of the logic comparison module. The output terminal of the signal conditioning module is connected to the input terminal of the feature extraction module. The peak hold output terminal and the timing voltage output terminal of the feature extraction module are respectively connected to the corresponding input terminals of the logic comparison module. The output terminal of the logic comparison module is connected to the input terminal of the delay confirmation and alarm lockout module.

[0011] Preferably, the signal conditioning module includes a first operational amplifier in an LM358 dual operational amplifier, a second operational amplifier in an LM358 dual operational amplifier, a first resistor, a second resistor, a third resistor, and a first capacitor. The non-inverting input of the first operational amplifier in the LM358 dual operational amplifier is connected to the signal output of the flow sensor. The output of the first operational amplifier in the LM358 dual operational amplifier is connected to its inverting input. The output of the first operational amplifier in the LM358 dual operational amplifier is connected to the non-inverting input of the second operational amplifier through the first resistor. The inverting input of the second operational amplifier in the LM358 dual operational amplifier is grounded through the second resistor. The inverting input of the second operational amplifier in the LM358 dual operational amplifier is connected to its output through the third resistor. A first capacitor is connected in parallel between the output of the second operational amplifier in the LM358 dual operational amplifier and ground.

[0012] Preferably, the feature extraction module includes a peak detection unit, which includes a third operational amplifier in an LM358 dual operational amplifier, a first diode, a second capacitor, a fourth resistor, and a first CD4066 analog switch. The non-inverting input of the third operational amplifier in the LM358 dual operational amplifier is connected to the output of the signal conditioning module. The output of the third operational amplifier in the LM358 dual operational amplifier is connected to its inverting input and the anode of the first diode. The cathode of the first diode is connected to the positive terminal of the second capacitor, and the negative terminal of the second capacitor is grounded. The fourth resistor is connected in parallel across the second capacitor, and the first CD4066 analog switch is connected in parallel across the second capacitor. The control terminal of the first CD4066 analog switch is used to receive a reset signal.

[0013] Preferably, the feature extraction module further includes an action timing unit, which includes a fourth operational amplifier in an LM358 dual operational amplifier, a fifth resistor, a third capacitor, and a second CD4066 analog switch. The non-inverting input of the fourth operational amplifier in the LM358 dual operational amplifier is connected to the output of the signal conditioning module, the inverting input of the fourth operational amplifier in the LM358 dual operational amplifier is connected to a first reference voltage, the output of the fourth operational amplifier in the LM358 dual operational amplifier is connected to the positive terminal of the third capacitor through the fifth resistor, the negative terminal of the third capacitor is grounded, the second CD4066 analog switch is connected in parallel across the third capacitor, and the control terminal of the second CD4066 analog switch is used to receive a reset signal.

[0014] Preferably, the dynamic reference module includes a first precision potentiometer and a second precision potentiometer. One end of the first precision potentiometer is connected to the positive terminal of the power supply, and the other end of the first precision potentiometer is grounded. Its sliding arm outputs a first reference voltage. One end of the second precision potentiometer is connected to the positive terminal of the power supply, and the other end of the second precision potentiometer is grounded. Its sliding arm outputs a second reference voltage.

[0015] Preferably, the logic comparison module includes a first comparator, a second comparator, and a third comparator in an LM339 voltage comparator, a first CD4081 AND gate, and a fourth capacitor. The inverting input of the first comparator in the LM339 voltage comparator is connected to the output of the signal conditioning module, and the non-inverting input of the first comparator in the LM339 voltage comparator is connected to a second reference voltage. The non-inverting input of the second comparator in the LM339 voltage comparator is connected to the peak hold output of the feature extraction module, and the inverting input of the second comparator in the LM339 voltage comparator... The input terminal is connected to the first reference voltage provided by the dynamic reference module. The non-inverting input terminal of the third comparator in the LM339 voltage comparator is connected to the timing voltage output terminal of the feature extraction module. The inverting input terminal of the third comparator in the LM339 voltage comparator is connected to the second reference voltage provided by the dynamic reference module. The output terminals of the second and third comparators in the LM339 voltage comparator are respectively connected to the two input terminals of the first CD4081 AND gate. The output terminal of the first comparator in the LM339 voltage comparator is coupled to the input terminal of the first CD4081 AND gate through the fourth capacitor.

[0016] Preferably, the delay confirmation and alarm lock module includes an NE555 timer, a thyristor, a sixth resistor, a seventh resistor, a fifth capacitor, and a manual reset button. The output of the logic comparison module is connected to the positive terminal of the fifth capacitor through the sixth resistor. The negative terminal of the fifth capacitor is grounded. The positive terminal of the fifth capacitor is connected to the trigger terminal of the NE555 timer. The output of the NE555 timer is connected to the gate of the thyristor through the seventh resistor. The anode of the thyristor is connected to the positive terminal of the power supply. The cathode of the thyristor is connected to an alarm. The manual reset button is connected in parallel between the anode and cathode of the thyristor.

[0017] This utility model has the following beneficial effects:

[0018] This invention dynamically monitors the air source flow rate on the intake pipe of the pneumatic angle seat valve, extracts the peak flow rate and action duration characteristics during its operation, and compares them with the preset normal reference value in real time. When both insufficient peak flow rate and action timeout are detected simultaneously, an alarm is triggered after a delay confirmation, thereby diagnosing the internal air leakage fault caused by piston sealing ring wear. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the structure of this utility model;

[0021] Figure 2 This is a structural block diagram of the internal leakage fault detection circuit in this utility model.

[0022] In the diagram: 1. Valve body; 2. Valve cover; 3. Connecting pipe; 4. Cylinder body; 5. Cylinder head; 6. Piston; 7. Return spring; 8. Inlet; 9. Outlet; 10. Valve stem; 11. Valve core; 12. Flow sensor; 13. Signal conditioning module; 14. Feature extraction module; 15. Dynamic reference module; 16. Logic comparison module; 17. Delay confirmation and alarm lockout module. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0024] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0025] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0026] In the description of this utility model, it should be understood that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the utility model product is in use, or the orientation or positional relationship commonly understood by those skilled in the art. They are only used to facilitate the description of this utility model and to simplify the description, and are not intended to indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0027] Furthermore, the terms "first," "second," and "third" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0028] In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0029] A pneumatic angle seat valve, such as Figure 1 As shown, the system includes a valve body 1, a valve cover 2 fixedly connected to the valve body 1, a connecting pipe 3 fixedly connected to the valve cover 2 and communicating with the inside of the valve body 1, a cylinder body 4 fixedly connected to the upper end of the connecting pipe 3 and communicating with it, a cylinder head 5 fixedly connected to the cylinder body 4, a piston 6 slidably connected to the inside of the cylinder body 4, a valve stem 10 fixedly connected to the piston 6 and passing through the connecting pipe 3 to the inside of the valve body 1, and a valve core 11 fixedly connected to the lower end of the valve stem 10 and located inside the valve body 1. A return spring 7 is provided inside the cylinder body 4 to abut against the piston 6 and the inner top surface of the cylinder head 5. The piston 6 divides the inside of the cylinder body 4 into an intake chamber and an outlet chamber. An intake port 8 communicating with the intake chamber and an outlet port 9 communicating with the outlet chamber are provided on the cylinder body 4. The intake port 8 is connected to an air compressor through an intake pipe. A flow sensor 12 is connected to the intake pipe. The flow sensor 12 is electrically connected to an internal leakage fault detection circuit.

[0030] like Figure 2 As shown, the internal leakage fault detection circuit includes a signal conditioning module 13, a feature extraction module 14, a dynamic reference module 15, a logic comparison module 16, and a delay confirmation and alarm locking module 17.

[0031] The input terminal of the signal conditioning module 13 is connected to the signal output terminal of the flow sensor 12. The dynamic reference module 15 is used to provide a reference voltage signal. The input terminal of the feature extraction module 14 is connected to the output terminal of the signal conditioning module 13. The first input terminal group of the logic comparison module 16 is connected to the output terminal of the feature extraction module 14. The second input terminal group of the logic comparison module 16 is connected to the output terminal of the dynamic reference module 15. The input terminal of the delay confirmation and alarm lockout module 17 is connected to the output terminal of the logic comparison module 16. The output terminal of the signal conditioning module 13 is connected to the input terminal of the feature extraction module 14. The peak hold output terminal and the timing voltage output terminal of the feature extraction module 14 are respectively connected to the corresponding input terminals of the logic comparison module 16. The output terminal of the logic comparison module 16 is connected to the input terminal of the delay confirmation and alarm lockout module 17.

[0032] The signal conditioning module 13 includes a first operational amplifier and a second operational amplifier in an LM358 dual operational amplifier, a first resistor, a second resistor, a third resistor, and a first capacitor. The non-inverting input of the first operational amplifier in the LM358 dual operational amplifier is connected to the signal output of the flow sensor 12. The output of the first operational amplifier in the LM358 dual operational amplifier is connected to its inverting input. The output of the first operational amplifier in the LM358 dual operational amplifier is connected to the non-inverting input of the second operational amplifier through the first resistor. The inverting input of the second operational amplifier in the LM358 dual operational amplifier is grounded through the second resistor. The inverting input of the second operational amplifier in the LM358 dual operational amplifier is connected to its output through the third resistor. A first capacitor is connected in parallel between the output of the second operational amplifier in the LM358 dual operational amplifier and ground.

[0033] The feature extraction module 14 includes a peak detection unit, which includes a third operational amplifier in an LM358 dual operational amplifier, a first diode, a second capacitor, a fourth resistor, and a first CD4066 analog switch. The non-inverting input of the third operational amplifier in the LM358 dual operational amplifier is connected to the output of the signal conditioning module 13. The output of the third operational amplifier in the LM358 dual operational amplifier is connected to its inverting input and the anode of the first diode. The cathode of the first diode is connected to the positive terminal of the second capacitor, and the negative terminal of the second capacitor is grounded. The fourth resistor is connected in parallel across the second capacitor, and the first CD4066 analog switch is connected in parallel across the second capacitor. The control terminal of the first CD4066 analog switch is used to receive a reset signal.

[0034] The feature extraction module 14 also includes an action timing unit, which includes a fourth operational amplifier in an LM358 dual operational amplifier, a fifth resistor, a third capacitor, and a second CD4066 analog switch. The non-inverting input of the fourth operational amplifier in the LM358 dual operational amplifier is connected to the output of the signal conditioning module 13, the inverting input of the fourth operational amplifier in the LM358 dual operational amplifier is connected to the first reference voltage, the output of the fourth operational amplifier in the LM358 dual operational amplifier is connected to the positive terminal of the third capacitor through the fifth resistor, the negative terminal of the third capacitor is grounded, the second CD4066 analog switch is connected in parallel across the third capacitor, and the control terminal of the second CD4066 analog switch is used to receive a reset signal.

[0035] The dynamic reference module 15 includes a first precision potentiometer and a second precision potentiometer. One end of the first precision potentiometer is connected to the positive terminal of the power supply, and the other end of the first precision potentiometer is grounded. Its slider outputs a first reference voltage. One end of the second precision potentiometer is connected to the positive terminal of the power supply, and the other end of the second precision potentiometer is grounded. Its slider outputs a second reference voltage.

[0036] Logic comparison module 16 includes a first comparator, a second comparator, and a third comparator in an LM339 voltage comparator, a first CD4081 AND gate, and a fourth capacitor. The inverting input of the first comparator in the LM339 voltage comparator is connected to the output of signal conditioning module 13, and the non-inverting input of the first comparator in the LM339 voltage comparator is connected to a second reference voltage. The non-inverting input of the second comparator in the LM339 voltage comparator is connected to the peak hold output of feature extraction module 14, and the inverting input of the second comparator in the LM339 voltage comparator is connected to... The first reference voltage is provided by the dynamic reference module 15. The non-inverting input of the third comparator in the LM339 voltage comparator is connected to the timing voltage output of the feature extraction module 14. The inverting input of the third comparator in the LM339 voltage comparator is connected to the second reference voltage provided by the dynamic reference module 15. The outputs of the second and third comparators in the LM339 voltage comparator are respectively connected to the two inputs of the first CD4081 AND gate. The output of the first comparator in the LM339 voltage comparator is coupled to the input of the first CD4081 AND gate through the fourth capacitor.

[0037] The delay confirmation and alarm lockout module 17 includes an NE555 timer, a thyristor, a sixth resistor, a seventh resistor, a fifth capacitor, and a manual reset button. The output of the logic comparison module 16 is connected to the positive terminal of the fifth capacitor through the sixth resistor. The negative terminal of the fifth capacitor is grounded. The positive terminal of the fifth capacitor is connected to the trigger terminal of the NE555 timer. The output of the NE555 timer is connected to the gate of the thyristor through the seventh resistor. The anode of the thyristor is connected to the positive terminal of the power supply. The cathode of the thyristor is connected to an alarm. The manual reset button is connected in parallel between the anode and cathode of the thyristor.

[0038] When this pneumatic angle seat valve is working, the flow sensor 12 monitors the compressed air flow that drives the pneumatic angle seat valve in real time. The original weak electrical signal output by the sensor is first sent to the signal conditioning module 13 for processing. In this module, the first operational amplifier in the LM358 dual operational amplifier acts as a voltage follower to provide high input impedance isolation, ensuring that the signal is transmitted without distortion. Then, the second operational amplifier in the LM358 dual operational amplifier forms a non-inverting amplifier circuit. With the cooperation of a precision resistor network, the signal is amplified to an amplitude range suitable for subsequent circuit processing. At the same time, the first capacitor effectively filters out high-frequency noise interference, thereby outputting a stable and reliable flow characteristic signal.

[0039] This signal is simultaneously sent to two parallel processing units of the feature extraction module 14. In the peak detection unit, the third operational amplifier in the LM358 dual operational amplifier still acts as a voltage follower to enhance the load-carrying capacity. Its output charges the second capacitor through the first diode. When the flow rate increases, the capacitor voltage rises accordingly. When the flow rate decreases, the first diode is reverse-cut off. The fourth resistor provides a slow discharge circuit so that the second capacitor always maintains the maximum voltage value within the operating cycle, which is the analog quantity corresponding to the peak flow rate.

[0040] In the action timing unit, the fourth operational amplifier in the LM358 dual operational amplifier acts as a comparator. When the flow signal exceeds the set first reference voltage, it indicates that the action has started. Its output becomes high and charges the third capacitor through the fifth resistor. The linear rise rate of the capacitor voltage is proportional to the time, thereby converting the action duration into the corresponding voltage value.

[0041] These two key electrical parameters are fed into the logic comparison module 16, where the second comparator in the LM358 dual operational amplifier compares the real-time peak voltage with the normal peak reference set by the first precision potentiometer in the dynamic reference module 15. If the current peak is too low, a high level is output.

[0042] The third comparator in the LM358 dual operational amplifier compares the real-time action time voltage with the normal time reference set by the second precision potentiometer. If the current time is too long, it outputs a high level. The first comparator in the LM358 dual operational amplifier continuously monitors the flow signal and outputs an action end signal when it is lower than the second reference voltage.

[0043] The first CD4081 AND gate will only output a high-level abnormal judgment signal when it simultaneously receives a low peak value signal, a timeout signal, and an action end signal.

[0044] After the signal enters the delay confirmation and alarm lockout module 17, it first charges the fifth capacitor through the sixth resistor. Only when the abnormal signal lasts for a sufficient time and the capacitor voltage reaches the timer trigger threshold will the NE555 timer be triggered and output a high level. This design effectively prevents false alarms caused by transient interference.

[0045] The high level output of the NE555 timer drives the thyristor to conduct through the seventh resistor. Once conducted, a self-locking circuit is formed, continuously activating the alarm. Even if the abnormal signal disappears, the alarm status remains until the maintenance personnel press the manual reset button to cut off the thyristor power supply circuit, which will then clear the alarm.

[0046] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A pneumatic angle seat valve characterized by, The valve body includes a valve body (1), a valve cover (2) fixedly connected to the valve body (1), a connecting pipe (3) fixedly connected to the valve cover (2) and communicating with the inside of the valve body (1), a cylinder body (4) fixedly connected to the upper end of the connecting pipe (3) and communicating with it, a cylinder cover (5) fixedly connected to the cylinder body (4), a piston (6) slidably connected to the cylinder body (4), a valve stem (10) fixedly connected to the piston (6) and passing through the connecting pipe (3) to the inside of the valve body (1), and a valve fixedly connected to the lower end of the valve stem (10) and located inside the valve body (1). The cylinder body (4) is provided with a return spring (7) that abuts against the piston (6) and the inner top surface of the cylinder head (5). The piston (6) divides the cylinder body (4) into an intake chamber and an outlet chamber. The cylinder body (4) is provided with an intake port (8) that communicates with the intake chamber and an outlet port (9) that communicates with the outlet chamber. The intake port (8) is connected to an air compressor through an intake pipe. A flow sensor (12) is connected to the intake pipe. The flow sensor (12) is electrically connected to an internal leakage fault detection circuit.

2. A pneumatic angle seat valve according to claim 1, wherein The internal leakage fault detection circuit includes a signal conditioning module (13), a feature extraction module (14), a dynamic reference module (15), a logic comparison module (16), and a delay confirmation and alarm locking module (17). The input terminal of the signal conditioning module (13) is connected to the signal output terminal of the flow sensor (12). The dynamic reference module (15) is used to provide a reference voltage signal. The input terminal of the feature extraction module (14) is connected to the output terminal of the signal conditioning module (13). The first input terminal group of the logic comparison module (16) is connected to the output terminal of the feature extraction module (14). The second input terminal group of the logic comparison module (16) is connected to the output terminal of the dynamic reference module (15). The input terminal of the delay confirmation and alarm lockout module (17) is connected to the output terminal of the logic comparison module (16). The output terminal of the signal conditioning module (13) is connected to the input terminal of the feature extraction module (14). The peak hold output terminal and the timing voltage output terminal of the feature extraction module (14) are respectively connected to the corresponding input terminals of the logic comparison module (16). The output terminal of the logic comparison module (16) is connected to the input terminal of the delay confirmation and alarm lockout module (17).

3. A pneumatic angle seat valve according to claim 2, wherein The signal conditioning module (13) includes a first operational amplifier in an LM358 dual operational amplifier, a second operational amplifier in an LM358 dual operational amplifier, a first resistor, a second resistor, a third resistor, and a first capacitor. The non-inverting input terminal of the first operational amplifier in the LM358 dual operational amplifier is connected to the signal output terminal of the flow sensor (12). The output terminal of the first operational amplifier in the LM358 dual operational amplifier is connected to its inverting input terminal. The output terminal of the first operational amplifier in the LM358 dual operational amplifier is connected to the non-inverting input terminal of the second operational amplifier through the first resistor. The inverting input terminal of the second operational amplifier in the LM358 dual operational amplifier is grounded through the second resistor. The inverting input terminal of the second operational amplifier in the LM358 dual operational amplifier is connected to its output terminal through the third resistor. A first capacitor is connected in parallel between the output terminal of the second operational amplifier in the LM358 dual operational amplifier and ground.

4. A pneumatic angle seat valve according to claim 2, wherein The feature extraction module (14) includes a peak detection unit, which includes a third operational amplifier in an LM358 dual operational amplifier, a first diode, a second capacitor, a fourth resistor, and a first CD4066 analog switch. The non-inverting input of the third operational amplifier in the LM358 dual operational amplifier is connected to the output of the signal conditioning module (13). The output of the third operational amplifier in the LM358 dual operational amplifier is connected to its inverting input and the anode of the first diode. The cathode of the first diode is connected to the positive terminal of the second capacitor. The negative terminal of the second capacitor is grounded. The fourth resistor is connected in parallel across the two ends of the second capacitor. The first CD4066 analog switch is connected in parallel across the two ends of the second capacitor. The control terminal of the first CD4066 analog switch is used to receive a reset signal.

5. A pneumatic angle seat valve according to claim 2, wherein The feature extraction module (14) further includes an action timing unit, which includes a fourth operational amplifier in an LM358 dual operational amplifier, a fifth resistor, a third capacitor, and a second CD4066 analog switch. The non-inverting input of the fourth operational amplifier in the LM358 dual operational amplifier is connected to the output of the signal conditioning module (13). The inverting input of the fourth operational amplifier in the LM358 dual operational amplifier is connected to a first reference voltage. The output of the fourth operational amplifier in the LM358 dual operational amplifier is connected to the positive terminal of the third capacitor through the fifth resistor. The negative terminal of the third capacitor is grounded. The second CD4066 analog switch is connected in parallel across the three terminals of the third capacitor. The control terminal of the second CD4066 analog switch is used to receive a reset signal.

6. A pneumatic angle seat valve according to claim 2, wherein The dynamic reference module (15) includes a first precision potentiometer and a second precision potentiometer. One end of the first precision potentiometer is connected to the positive terminal of the power supply, and the other end of the first precision potentiometer is grounded. Its sliding arm outputs a first reference voltage. One end of the second precision potentiometer is connected to the positive terminal of the power supply, and the other end of the second precision potentiometer is grounded. Its sliding arm outputs a second reference voltage.

7. A pneumatic angle seat valve according to claim 2, wherein The logic comparison module (16) includes a first comparator, a second comparator, and a third comparator in an LM339 voltage comparator, a first CD4081 AND gate, and a fourth capacitor. The inverting input of the first comparator in the LM339 voltage comparator is connected to the output of the signal conditioning module (13), and the non-inverting input of the first comparator in the LM339 voltage comparator is connected to a second reference voltage. The non-inverting input of the second comparator in the LM339 voltage comparator is connected to the peak hold output of the feature extraction module (14), and the inverting input of the second comparator in the LM339 voltage comparator is connected to the peak hold output of the feature extraction module (14). The first reference voltage is provided by the dynamic reference module (15). The non-inverting input of the third comparator in the LM339 voltage comparator is connected to the timing voltage output of the feature extraction module (14). The inverting input of the third comparator in the LM339 voltage comparator is connected to the second reference voltage provided by the dynamic reference module (15). The outputs of the second and third comparators in the LM339 voltage comparator are respectively connected to the two inputs of the first CD4081 AND gate. The output of the first comparator in the LM339 voltage comparator is coupled to the input of the first CD4081 AND gate through the fourth capacitor.

8. A pneumatic angle seat valve according to claim 2, wherein, The delay confirmation and alarm lock module (17) includes an NE555 timer, a thyristor, a sixth resistor, a seventh resistor, a fifth capacitor, and a manual reset button. The output of the logic comparison module (16) is connected to the positive terminal of the fifth capacitor through the sixth resistor. The negative terminal of the fifth capacitor is grounded. The positive terminal of the fifth capacitor is connected to the trigger terminal of the NE555 timer. The output of the NE555 timer is connected to the gate of the thyristor through the seventh resistor. The anode of the thyristor is connected to the positive terminal of the power supply. The cathode of the thyristor is connected to an alarm. The manual reset button is connected in parallel between the anode and cathode of the thyristor.

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