A dark rod wedge type forged steel gate valve

Abstract

The utility model discloses a kind of dark rod wedge type forged steel gate valves, belong to gate valve technical field, solve the problem of false position caused by the inconsistency of valve real and display switch state in the working of dark rod wedge type forged steel gate valve, due to the wear and tear fracture of mechanical position indicator and the connecting gear of valve stem, pin key, or the stripping of gate plate nut thread under extreme overload, valve stem idle running, the false position problem of valve real and display switch state inconsistency is caused. Including gate valve body, and the false position fault identification circuit being set on gate valve body, the detection end of the false position fault identification circuit is connected with valve stem transmission in gate valve body. The utility model identifies the false position fault caused by mechanical transmission component failure by real-time monitoring valve stem rotary motion, operating torque and action time sequence and carrying out multi-parameter logic judgment, and triggers alarm signal when confirming fault, to prevent the operation accident caused by valve state misjudgment.

Description

Technical Field

[0001] This utility model relates to the field of gate valve technology, and in particular to a non-stick wedge forged steel gate valve. Background Technology

[0002] The non-protruding stem wedge forged steel gate valve is a commonly used valve in industrial high-pressure pipelines. Made of forged steel, it is resistant to high pressure and high temperature. The non-protruding stem design prevents the valve stem from being exposed during opening and closing. Combined with a wedge gate, it achieves a reliable seal. It is suitable for petroleum, power and other scenarios, and can conveniently control the flow of media, ensuring stable pipeline operation.

[0003] During operation, the non-circulating wedge forged steel gate valve may experience a "false position" problem where the actual valve opening and closing status is inconsistent with the status displayed by the control system. This can occur due to wear or breakage of components such as gears and pins connecting the mechanical position indicator and the valve stem, or, under extreme overload conditions, complete stripping of the gate nut threads causing the valve stem to spin freely. This problem can directly lead to operators misjudging the process flow, potentially causing serious consequences such as incorrect media cut-off or flow, abnormal system pressure, and ultimately resulting in equipment damage or even safety accidents.

[0004] Therefore, a concealed stem wedge-type forged steel gate valve is proposed to solve or alleviate the above problems. Utility Model Content

[0005] The purpose of this utility model is to address the shortcomings of existing technologies by proposing a concealed stem wedge-type forged steel gate valve.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A forged steel gate valve with a concealed stem wedge includes a gate valve body and a false position fault identification circuit disposed on the gate valve body. The detection end of the false position fault identification circuit is connected to the valve stem in the gate valve body. The false position fault identification circuit monitors the rotational movement, dynamic torque and operation timing of the valve stem in the gate valve body and cross-verifies the false position signal. When a false position signal is detected, it outputs a fault alarm signal.

[0007] Preferably, the false position fault identification circuit includes a signal processing module, a rotational speed and acceleration monitoring module, a dynamic torque monitoring module, a multi-channel signal synchronous sampling module, an analog feature value comparison module, a timing logic state machine module, and a multi-condition latching alarm module. The incremental rotary encoder in the signal processing module is coaxially fixed to the valve stem in the gate valve body via a rigid coupling. The dynamic torque monitoring module is located within the gate valve body and is drively connected to the valve stem. The frequency multiplication pulse output terminal of the signal processing module is connected to the pulse signal input terminal of the rotational speed and acceleration monitoring module. The direction signal output terminal of the signal processing module is connected to the direction control output terminal of the timing logic state machine module. The input terminals are connected as follows: the speed pulse signal output terminal and acceleration signal output terminal of the speed and acceleration monitoring module, and the torque signal output terminal of the dynamic torque monitoring module are respectively connected to the corresponding analog signal input terminals of the multi-channel signal synchronous sampling module; the multi-channel synchronous sampling output terminal of the multi-channel signal synchronous sampling module is correspondingly connected to the multi-channel analog signal input terminal of the analog feature value comparison module; the multi-channel digital fault signal output terminal of the analog feature value comparison module is connected to the corresponding fault condition input terminal of the multi-condition latching alarm module; and the position over-limit signal output terminal and running timeout signal output terminal of the timing logic state machine module are connected to the corresponding logic condition input terminal of the multi-condition latching alarm module.

[0008] Preferably, the signal processing module includes an incremental rotary encoder, a first Schmitt trigger CD40106, a second Schmitt trigger CD40106, and an XOR gate CD4070. The A-phase output pin of the incremental rotary encoder is connected to the signal input terminal of the first Schmitt trigger CD40106, and the signal output terminal of the first Schmitt trigger CD40106 outputs a clock signal. The B-phase output pin of the incremental rotary encoder is connected to the signal input terminal of the second Schmitt trigger CD40106, and the signal output terminal of the second Schmitt trigger CD40106 outputs a clock signal. The first Schmitt trigger CD40106 outputs a direction signal at its first output terminal. The signal output terminal of the first Schmitt trigger CD40106 is connected to the first input terminal of the first XOR unit and the first input terminal of the second XOR unit of the XOR gate CD4070. The signal output terminal of the second Schmitt trigger CD40106 is connected to the second input terminal of the first XOR unit and the second input terminal of the second XOR unit of the XOR gate CD4070. The output terminal of the first XOR unit of the XOR gate CD4070 outputs a quadruple frequency pulse signal. The output terminal of the second XOR unit of the XOR gate CD4070 outputs a precise direction signal.

[0009] Preferably, the rotational speed and acceleration monitoring module includes a first monostable multivibrator CD4538 and a second monostable multivibrator CD4538. The positive-phase trigger input terminal of the first monostable multivibrator CD4538 receives a fourth-harmonic pulse signal, and the signal output terminal of the first monostable multivibrator CD4538 outputs a rotational speed pulse signal. A first resistor and a first capacitor are connected between the external resistor terminal and the external capacitor terminal of the first monostable multivibrator CD4538. The signal output terminal of the first monostable multivibrator CD4538 is connected to the inverting trigger input terminal of the second monostable multivibrator CD4538. The signal output terminal of the second monostable multivibrator CD4538 outputs an acceleration signal, and a second resistor and a second capacitor are connected between the external resistor terminal and the external capacitor terminal of the second monostable multivibrator CD4538.

[0010] Preferably, the dynamic torque monitoring module includes a resistance strain gauge torque sensor, a dual operational amplifier LM358, a first switching diode, and a first holding capacitor. The voltage output pin of the resistance strain gauge torque sensor is connected to the non-inverting input of the first operational amplifier in the dual operational amplifier LM358. The output of the first operational amplifier in the dual operational amplifier LM358 is connected to the anode of the first switching diode. The cathode of the first switching diode is connected to one end of the first holding capacitor. The other end of the first holding capacitor is grounded. The voltage across the first holding capacitor is connected to the non-inverting input of the second operational amplifier in the dual operational amplifier LM358. The output of the second operational amplifier in the dual operational amplifier LM358 outputs a peak torque signal.

[0011] Preferably, the multi-channel signal synchronization sampling module includes an analog multiplexer CD4051 and a first sample-and-hold circuit, a second sample-and-hold circuit, and a third sample-and-hold circuit. The analog signal input terminal of the first sample-and-hold circuit receives a rotational speed pulse signal, the analog signal input terminal of the second sample-and-hold circuit receives an acceleration signal, and the analog signal input terminal of the third sample-and-hold circuit receives a peak torque signal. The first channel output terminal, the second channel output terminal, and the third channel output terminal of the analog multiplexer CD4051 are respectively connected to the sampling and holding control terminals of the first sample-and-hold circuit, the second sample-and-hold circuit, and the third sample-and-hold circuit. The analog signal output terminal of the first sample-and-hold circuit outputs a synchronized sampled rotational speed signal, the analog signal output terminal of the second sample-and-hold circuit outputs a synchronized sampled acceleration signal, and the analog signal output terminal of the third sample-and-hold circuit outputs a synchronized sampled torque signal.

[0012] Preferably, the analog characteristic value comparison module includes a precision reference voltage source TL431 and a four-channel differential comparator LM339. The precision reference voltage source TL431 provides speed threshold voltage, acceleration threshold voltage, and torque threshold voltage through a voltage divider resistor network. The inverting input of the first comparator in the four-channel differential comparator LM339 receives the sampled speed signal, the non-inverting input of the first comparator in the four-channel differential comparator LM339 receives the speed threshold voltage, and the output of the first comparator in the four-channel differential comparator LM339 outputs a speed fault signal. The inverting input of the second comparator in the LM339 receives the sampled acceleration signal, the non-inverting input of the second comparator in the four-channel differential comparator LM339 receives the acceleration threshold voltage, the output of the second comparator in the four-channel differential comparator LM339 outputs an acceleration fault signal, the inverting input of the third comparator in the four-channel differential comparator LM339 receives the sampled torque signal, the non-inverting input of the third comparator in the four-channel differential comparator LM339 receives the torque threshold voltage, and the output of the third comparator in the four-channel differential comparator LM339 outputs a torque fault signal.

[0013] Preferably, the sequential logic state machine module includes a presettable binary up / down counter CD4029, a dual D flip-flop CD4013, and an AND gate CD4081. The clock input of the presettable binary up / down counter CD4029 receives a quadruple frequency pulse signal, the up / down control terminal of the presettable binary up / down counter CD4029 receives a precise direction signal, the parallel data output terminal of the presettable binary up / down counter CD4029 is connected to the corresponding input terminal of the AND gate CD4081, the output terminal of the AND gate CD4081 outputs a position over-limit signal, and the clock input of the first D flip-flop in the dual D flip-flop CD4013 receives a valve start signal.

[0014] Preferably, the multi-condition latching alarm module includes an AND-OR-NOT gate CD4085, a four-RS latch CD4043, and an optocoupler. The input terminals of the first AND gate of the AND-OR-NOT gate CD4085 receive a speed fault signal and an acceleration fault signal. The input terminals of the second AND gate of the AND-OR-NOT gate CD4085 receive a torque fault signal and a position over-limit signal. The output terminal of the AND-OR-NOT gate CD4085 is connected to the set terminal of the first RS latch in the four-RS latch CD4043. The set terminal of the second RS latch in the four-RS latch CD4043 receives a state machine timeout signal. The output terminals of the first RS latch and the second RS latch are connected to the anode of the light-emitting diode in the optocoupler through an AND gate. The collector terminal of the phototransistor in the optocoupler is used to drive the coil of an external alarm relay.

[0015] This utility model has the following beneficial effects: This invention identifies false position faults caused by the failure of mechanical transmission components by real-time monitoring of valve stem rotation, operating torque, and action timing, and performs multi-parameter logical judgments. When a fault is confirmed, an alarm signal is triggered, thereby preventing operational accidents caused by misjudgment of valve status. Attached Figure Description

[0016] 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.

[0017] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 This is a structural block diagram of the false location fault identification circuit in this utility model.

[0018] 1. Gate valve body; 2. Signal processing module; 3. Rotation speed and acceleration monitoring module; 4. Dynamic torque monitoring module; 5. Multi-channel signal synchronous sampling module; 6. Analog feature value comparison module; 7. Timing logic state machine module; 8. Multi-condition latching alarm module. Detailed Implementation

[0019] 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.

[0020] 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.

[0021] 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.

[0022] 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.

[0023] Furthermore, the terms "first," "second," and "third" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0024] 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.

[0025] A type of forged steel wedge gate valve with a non-bulking stem, such as Figure 1 As shown, the device includes a gate valve body 1 and a false position fault identification circuit installed on the gate valve body 1. The detection end of the false position fault identification circuit is connected to the valve stem in the gate valve body 1. The false position fault identification circuit monitors the rotational movement, dynamic torque and operation timing of the valve stem in the gate valve body 1 and cross-verifies the false position signal. When a false position signal is detected, it outputs a fault alarm signal.

[0026] like Figure 2As shown, the false position fault identification circuit includes a signal processing module 2, a speed and acceleration monitoring module 3, a dynamic torque monitoring module 4, a multi-channel signal synchronous sampling module 5, an analog feature value comparison module 6, a timing logic state machine module 7, and a multi-condition latching alarm module 8. The incremental rotary encoder in the signal processing module 2 is coaxially fixed to the valve stem in the gate valve body 1 via a rigid coupling. The dynamic torque monitoring module 4 is located inside the gate valve body 1 and is connected to the valve stem in the gate valve body 1. The frequency multiplication pulse output terminal of the signal processing module 2 is connected to the pulse signal input terminal of the speed and acceleration monitoring module 3. The direction signal output terminal of the signal processing module 2 is connected to the direction control terminal of the timing logic state machine module 7. The speed pulse signal output terminal and acceleration signal output terminal of the speed and acceleration monitoring module 3, and the torque signal output terminal of the dynamic torque monitoring module 4 are respectively connected to the corresponding analog signal input terminals of the multi-channel signal synchronous sampling module 5. The multi-channel synchronous sampling output terminal of the multi-channel signal synchronous sampling module 5 is connected to the corresponding multi-channel analog signal input terminal of the analog feature value comparison module 6. The multi-channel digital fault signal output terminal of the analog feature value comparison module 6 is connected to the corresponding fault condition input terminal of the multi-condition latching alarm module 8. The position over-limit signal output terminal and the running timeout signal output terminal of the timing logic state machine module 7 are connected to the corresponding logic condition input terminal of the multi-condition latching alarm module 8.

[0027] Signal processing module 2 includes an incremental rotary encoder, a first Schmitt trigger CD40106, a second Schmitt trigger CD40106, and an XOR gate CD4070. The A-phase output pin of the incremental rotary encoder is connected to the signal input terminal of the first Schmitt trigger CD40106, and the signal output terminal of the first Schmitt trigger CD40106 outputs a clock signal. The B-phase output pin of the incremental rotary encoder is connected to the signal input terminal of the second Schmitt trigger CD40106, and the signal output terminal of the second Schmitt trigger CD40106 outputs a direction signal. The signal output terminal of the first Schmitt trigger CD40106 is connected to the first input terminal of the first XOR unit and the first input terminal of the second XOR unit of the XOR gate CD4070. The signal output terminal of the second Schmitt trigger CD40106 is connected to the second input terminal of the first XOR unit and the second XOR unit of the XOR gate CD4070. The output terminal of the first XOR unit of the XOR gate CD4070 outputs a quadruple frequency pulse signal, and the output terminal of the second XOR unit of the XOR gate CD4070 outputs a precise direction signal.

[0028] The rotational speed and acceleration monitoring module 3 includes a first monostable multivibrator CD4538 and a second monostable multivibrator CD4538. The positive-phase trigger input terminal of the first monostable multivibrator CD4538 receives a fourth-harmonic pulse signal, and the signal output terminal of the first monostable multivibrator CD4538 outputs a rotational speed pulse signal. A first resistor and a first capacitor are connected between the external resistor terminal and the external capacitor terminal of the first monostable multivibrator CD4538. The signal output terminal of the first monostable multivibrator CD4538 is connected to the inverting trigger input terminal of the second monostable multivibrator CD4538, and the signal output terminal of the second monostable multivibrator CD4538 outputs an acceleration signal. A second resistor and a second capacitor are connected between the external resistor terminal and the external capacitor terminal of the second monostable multivibrator CD4538.

[0029] The dynamic torque monitoring module 4 includes a resistance strain gauge torque sensor, a dual operational amplifier LM358, a first switching diode, and a first holding capacitor. The voltage output pin of the resistance strain gauge torque sensor is connected to the non-inverting input of the first operational amplifier in the dual operational amplifier LM358. The output of the first operational amplifier in the dual operational amplifier LM358 is connected to the anode of the first switching diode. The cathode of the first switching diode is connected to one end of the first holding capacitor. The other end of the first holding capacitor is grounded. The voltage across the first holding capacitor is connected to the non-inverting input of the second operational amplifier in the dual operational amplifier LM358. The output of the second operational amplifier in the dual operational amplifier LM358 outputs the peak torque signal.

[0030] The multi-channel signal synchronous sampling module 5 includes an analog multiplexer CD4051 and a first sample-and-hold circuit, a second sample-and-hold circuit, and a third sample-and-hold circuit. The analog signal input terminal of the first sample-and-hold circuit receives a speed pulse signal, the analog signal input terminal of the second sample-and-hold circuit receives an acceleration signal, and the analog signal input terminal of the third sample-and-hold circuit receives a peak torque signal. The first channel output terminal, the second channel output terminal, and the third channel output terminal of the analog multiplexer CD4051 are respectively connected to the sampling and holding control terminals of the first sample-and-hold circuit, the second sample-and-hold circuit, and the third sample-and-hold circuit. The analog signal output terminal of the first sample-and-hold circuit outputs a synchronized sampled speed signal, the analog signal output terminal of the second sample-and-hold circuit outputs a synchronized sampled acceleration signal, and the analog signal output terminal of the third sample-and-hold circuit outputs a synchronized sampled torque signal.

[0031] The analog characteristic value comparison module 6 includes a precision reference voltage source TL431 and a four-channel differential comparator LM339. The precision reference voltage source TL431 provides speed threshold voltage, acceleration threshold voltage, and torque threshold voltage through a voltage divider resistor network. The inverting input of the first comparator in the four-channel differential comparator LM339 receives the sampled speed signal, the non-inverting input receives the speed threshold voltage, and the output of the first comparator outputs a speed fault signal. The inverting input of the second comparator in the LM339 receives the sampled acceleration signal. The non-inverting input of the second comparator in the four-channel differential comparator LM339 receives the acceleration threshold voltage. The output of the second comparator in the four-channel differential comparator LM339 outputs an acceleration fault signal. The inverting input of the third comparator in the four-channel differential comparator LM339 receives the sampled torque signal. The non-inverting input of the third comparator in the four-channel differential comparator LM339 receives the torque threshold voltage. The output of the third comparator in the four-channel differential comparator LM339 outputs a torque fault signal.

[0032] The sequential logic state machine module 7 includes a presettable binary up / down counter CD4029, a dual D flip-flop CD4013, and an AND gate CD4081. The clock input of the presettable binary up / down counter CD4029 receives a quadruple frequency pulse signal. The up / down control terminal of the presettable binary up / down counter CD4029 receives a precise direction signal. The parallel data output terminal of the presettable binary up / down counter CD4029 is connected to the corresponding input terminal of the AND gate CD4081. The output terminal of the AND gate CD4081 outputs a position over-limit signal. The clock input terminal of the first D flip-flop in the dual D flip-flop CD4013 receives a valve start signal.

[0033] The multi-condition latching alarm module 8 includes an AND-OR-NOT gate CD4085, a quad RS latch CD4043, and an optocoupler. The input terminals of the first AND gate of the AND-OR-NOT gate CD4085 receive speed fault signals and acceleration fault signals. The input terminals of the second AND gate of the AND-OR-NOT gate CD4085 receive torque fault signals and position over-limit signals. The output terminal of the AND-OR-NOT gate CD4085 is connected to the set terminal of the first RS latch in the quad RS latch CD4043. The set terminal of the second RS latch in the quad RS latch CD4043 receives a state machine timeout signal. The output terminals of the first RS latch and the second RS latch are connected to the anode of the light-emitting diode in the optocoupler through an AND gate. The collector terminal of the phototransistor in the optocoupler is used to drive the coil of the external alarm relay.

[0034] When this concealed stem wedge forged steel gate valve is in operation, the false position fault identification circuit synchronously monitors and correlates various physical parameters during valve operation. When the operator turns the handwheel to try to open or close the gate valve body 1, the entire false position fault identification circuit immediately enters the working state. The incremental rotary encoder connected to the valve stem drive begins to rotate synchronously, accurately generating A and B two-phase quadrature pulse signals. These raw signals are shaped by the Schmitt trigger to eliminate contact jitter and noise interference, and then sent to the XOR gate for signal processing. This not only generates a quadruple frequency pulse, which greatly improves the angular resolution, but also outputs a precise directional signal to clearly identify the valve operation direction. This key signal is sent in parallel to the subsequent two processing paths.

[0035] On one hand, the fourth-harmonic pulse enters the speed acceleration monitoring module 3, and the pulse frequency is converted into a pulse signal with a specific width through two cascaded monostable multivibrators. The pulse width output by the first oscillator is inversely proportional to the instantaneous speed of the valve stem, while the second oscillator generates a signal reflecting the motion acceleration state by monitoring the rate of change of speed. These two analog quantities respectively reflect the dynamic characteristics of the valve stem motion.

[0036] On the other hand, the resistance strain gauge torque sensor is directly connected in the mechanical transmission path between the handwheel and the valve stem. It obtains the most accurate load information by measuring the actual torque applied by the operator. This installation method ensures that abnormalities in the entire torque transmission chain from the handwheel to the valve stem can be accurately captured.

[0037] During the signal acquisition phase, the analog multiplexer in the multi-channel signal synchronous sampling module 5, under unified clock control, synchronously triggers three sample-and-hold circuits to instantaneously sample and hold the voltage values ​​of the analog signals representing rotational speed, acceleration, and operating torque. This synchronization process is crucial because it ensures the complete temporal correspondence of different physical quantities and eliminates judgment errors caused by signal transmission delays. Subsequently, these synchronized sampled signals are sent in parallel to the analog characteristic value comparison module 6. The precision reference voltage source in this module is pre-set with several key parameters such as the safe upper limit of rotational speed, the reasonable range of acceleration, and the normal operating threshold of torque based on the normal operating characteristics of the valve. The four differential comparators quickly compare the real-time sampled signals with these preset thresholds. When a combination of abnormally high rotational speed accompanied by a significant decrease in torque occurs, it indicates that the valve stem may be in an idling state.

[0038] When a violent fluctuation in acceleration and abnormal oscillation of torque are detected, it indicates that the transmission components may be stuck or partially broken.

[0039] When the rotational speed is normal but the torque remains low and the position signal does not change, it indicates that the gate nut may have completely peeled off, causing a power transmission interruption. These comparators will immediately output the corresponding fault indicator signal.

[0040] These initial fault indicators do not directly trigger the final alarm. Instead, they work in conjunction with the timing logic state machine module 7 for comprehensive decision-making. The state machine module uses a quadruple frequency pulse as a precise displacement measurement reference and a direction signal to determine the valve's operational intent. Its internal binary counter continuously accumulates the number of valve stem rotations. If the count exceeds the maximum number of rotations required for the full stroke as preset according to the valve specifications, and the mechanical limit switch has not yet triggered, a position over-limit signal is generated. Simultaneously, the timing logic composed of D flip-flops monitors whether the entire operation process is completed within a reasonable time range. Any abnormal delay will generate a timeout flag. Finally, all judgment conditions are gathered to the multi-condition latching alarm module 8 for final adjudication. The AND, OR, and NOT logic within this module... The chip first intelligently groups and fuses highly correlated fault signals. For example, abnormal speed and abnormal acceleration are combined into a motion characteristic fault, and abnormal torque and excessive position are combined into a load characteristic fault. These fused signals are then sent to the RS latch. The latch is only set and the alarm state is maintained when the selected combination of fault conditions is met simultaneously. This multi-condition judgment mechanism greatly improves the system's ability to resist false alarms. The confirmed fault signal finally drives the external alarm relay through the optocoupler, enabling operators to detect the "false position" state in time and take emergency intervention measures, thereby effectively avoiding serious consequences such as incorrect cut-off or flow of the medium and loss of system pressure due to misjudgment of valve status.

[0041] 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 wedge-type forged steel gate valve with a concealed stem, characterized in that, The system includes a gate valve body (1) and a false position fault identification circuit installed on the gate valve body (1). The detection end of the false position fault identification circuit is connected to the valve stem in the gate valve body (1). The false position fault identification circuit monitors the rotational movement, dynamic torque and operation timing of the valve stem in the gate valve body (1) and cross-verifies the false position signal. When a false position signal is detected, the circuit outputs a fault alarm signal.

2. The forged steel gate valve with a concealed stem according to claim 1, characterized in that, The false position fault identification circuit includes a signal processing module (2), a speed acceleration monitoring module (3), a dynamic torque monitoring module (4), a multi-channel signal synchronous sampling module (5), an analog feature value comparison module (6), a timing logic state machine module (7), and a multi-condition latching alarm module (8). The incremental rotary encoder in the signal processing module (2) is coaxially fixed on the valve stem in the gate valve body (1) through a rigid coupling. The dynamic torque monitoring module (4) is located inside the gate valve body (1) and is connected to the valve stem in the gate valve body (1). The frequency multiplication pulse output terminal of the signal processing module (2) is connected to the pulse signal input terminal of the speed acceleration monitoring module (3). The direction signal output terminal of the signal processing module (2) is connected to the timing logic state machine module (8). 7) The direction control input terminal is connected, the speed pulse signal output terminal and acceleration signal output terminal of the speed acceleration monitoring module (3) and the torque signal output terminal of the dynamic torque monitoring module (4) are respectively connected to the corresponding analog signal input terminal of the multi-channel signal synchronous sampling module (5), the multi-channel synchronous sampling output terminal of the multi-channel signal synchronous sampling module (5) is connected to the corresponding multi-channel analog signal input terminal of the analog feature value comparison module (6), the multi-channel digital fault signal output terminal of the analog feature value comparison module (6) is connected to the corresponding fault condition input terminal of the multi-condition latch alarm module (8), and the position over-limit signal output terminal and the running timeout signal output terminal of the timing logic state machine module (7) are connected to the corresponding logic condition input terminal of the multi-condition latch alarm module (8).

3. A forged steel gate valve with a concealed stem according to claim 2, characterized in that, The signal processing module (2) includes an incremental rotary encoder, a first Schmitt trigger CD40106, a second Schmitt trigger CD40106, and an XOR gate CD4070. The A-phase output pin of the incremental rotary encoder is connected to the signal input terminal of the first Schmitt trigger CD40106, and the signal output terminal of the first Schmitt trigger CD40106 outputs a clock signal. The B-phase output pin of the incremental rotary encoder is connected to the signal input terminal of the second Schmitt trigger CD40106, and the signal output terminal of the second Schmitt trigger CD40106 outputs a clock signal. The first Schmitt trigger CD40106 outputs a direction signal at its first output terminal. The signal output terminal of the first Schmitt trigger CD40106 is connected to the first input terminal of the first XOR unit and the first input terminal of the second XOR unit of the XOR gate CD4070. The signal output terminal of the second Schmitt trigger CD40106 is connected to the second input terminal of the first XOR unit and the second input terminal of the second XOR unit of the XOR gate CD4070. The output terminal of the first XOR unit of the XOR gate CD4070 outputs a quadruple frequency pulse signal. The output terminal of the second XOR unit of the XOR gate CD4070 outputs a precise direction signal.

4. A forged steel gate valve with a concealed stem wedge as described in claim 2, characterized in that, The rotational speed and acceleration monitoring module (3) includes a first monostable multivibrator CD4538 and a second monostable multivibrator CD4538. The positive-phase trigger input terminal of the first monostable multivibrator CD4538 receives a fourth-harmonic pulse signal. The signal output terminal of the first monostable multivibrator CD4538 outputs a rotational speed pulse signal. A first resistor and a first capacitor are connected between the external resistor terminal and the external capacitor terminal of the first monostable multivibrator CD4538. The signal output terminal of the first monostable multivibrator CD4538 is connected to the inverted-phase trigger input terminal of the second monostable multivibrator CD4538. The signal output terminal of the second monostable multivibrator CD4538 outputs an acceleration signal. A second resistor and a second capacitor are connected between the external resistor terminal and the external capacitor terminal of the second monostable multivibrator CD4538.

5. A forged steel gate valve with a concealed stem according to claim 2, characterized in that, The dynamic torque monitoring module (4) includes a resistance strain gauge torque sensor, a dual operational amplifier LM358, a first switching diode, and a first holding capacitor. The voltage output pin of the resistance strain gauge torque sensor is connected to the non-inverting input of the first operational amplifier in the dual operational amplifier LM358. The output of the first operational amplifier in the dual operational amplifier LM358 is connected to the anode of the first switching diode. The cathode of the first switching diode is connected to one end of the first holding capacitor. The other end of the first holding capacitor is grounded. The voltage across the first holding capacitor is connected to the non-inverting input of the second operational amplifier in the dual operational amplifier LM358. The output of the second operational amplifier in the dual operational amplifier LM358 outputs a peak torque signal.

6. A forged steel gate valve with a concealed stem wedge as described in claim 2, characterized in that, The multi-channel signal synchronization sampling module (5) includes an analog multiplexer CD4051 and a first sample-and-hold circuit, a second sample-and-hold circuit, and a third sample-and-hold circuit. The analog signal input terminal of the first sample-and-hold circuit receives a rotational speed pulse signal, the analog signal input terminal of the second sample-and-hold circuit receives an acceleration signal, and the analog signal input terminal of the third sample-and-hold circuit receives a peak torque signal. The first channel output terminal, the second channel output terminal, and the third channel output terminal of the analog multiplexer CD4051 are respectively connected to the sampling and holding control terminals of the first sample-and-hold circuit, the second sample-and-hold circuit, and the third sample-and-hold circuit. The analog signal output terminal of the first sample-and-hold circuit outputs a synchronized sampled rotational speed signal, the analog signal output terminal of the second sample-and-hold circuit outputs a synchronized sampled acceleration signal, and the analog signal output terminal of the third sample-and-hold circuit outputs a synchronized sampled torque signal.

7. A forged steel gate valve with a concealed stem according to claim 2, characterized in that, The analog characteristic value comparison module (6) includes a precision reference voltage source TL431 and a four-channel differential comparator LM339. The precision reference voltage source TL431 provides speed threshold voltage, acceleration threshold voltage, and torque threshold voltage through a voltage divider resistor network. The inverting input of the first comparator in the four-channel differential comparator LM339 receives the sampled speed signal, the non-inverting input of the first comparator in the four-channel differential comparator LM339 receives the speed threshold voltage, and the output of the first comparator in the four-channel differential comparator LM339 outputs a speed fault signal. The inverting input of the second comparator in the LM339 receives the sampled acceleration signal, the non-inverting input of the second comparator in the four-channel differential comparator LM339 receives the acceleration threshold voltage, the output of the second comparator in the four-channel differential comparator LM339 outputs an acceleration fault signal, the inverting input of the third comparator in the four-channel differential comparator LM339 receives the sampled torque signal, the non-inverting input of the third comparator in the four-channel differential comparator LM339 receives the torque threshold voltage, and the output of the third comparator in the four-channel differential comparator LM339 outputs a torque fault signal.

8. A forged steel gate valve with a concealed stem wedge as described in claim 2, characterized in that, The sequential logic state machine module (7) includes a presettable binary up-down counter CD4029, a dual D flip-flop CD4013, and an AND gate CD4081. The clock input of the presettable binary up-down counter CD4029 receives a quadruple frequency pulse signal. The up-down control terminal of the presettable binary up-down counter CD4029 receives a precise direction signal. The parallel data output terminal of the presettable binary up-down counter CD4029 is connected to the corresponding input terminal of the AND gate CD4081. The output terminal of the AND gate CD4081 outputs a position over-limit signal. The clock input terminal of the first D flip-flop in the dual D flip-flop CD4013 receives a valve start signal.

9. A forged steel gate valve with a concealed stem according to claim 2, characterized in that, The multi-condition latch alarm module (8) includes an AND-OR-NOT gate CD4085, a quad RS latch CD4043, and an optocoupler. The input terminals of the first AND gate of the AND-OR-NOT gate CD4085 receive speed fault signals and acceleration fault signals. The input terminals of the second AND gate of the AND-OR-NOT gate CD4085 receive torque fault signals and position over-limit signals. The output terminal of the AND-OR-NOT gate CD4085 is connected to the set terminal of the first RS latch in the quad RS latch CD4043. The set terminal of the second RS latch in the quad RS latch CD4043 receives a state machine timeout signal. The output terminals of the first RS latch and the second RS latch are connected to the anode of the light-emitting diode in the optocoupler through an AND gate. The collector terminal of the phototransistor in the optocoupler is used to drive the coil of an external alarm relay.

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