A mechanical induction alarm mechanism for abnormal valve opening
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-06-03
- Publication Date
- 2026-08-14
AI Technical Summary
[0005]本发明的目的在于提供一种阀门开度异常的机械感应报警机构，以解决现有阀门开度监测方式因阀杆弹性扭转变形导致检测基准偏差，从而引发虚假全关和持续性介质内漏的问题
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Figure CN122566006A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of valve detection technology, specifically to a mechanical sensing alarm mechanism for abnormal valve opening. Background Technology
[0002] To monitor valve operation in real time, existing technologies typically couple an opening indicator or angular displacement sensor onto the valve's drive end, such as the worm gear box output shaft or actuator connector. These sensors indirectly determine the valve disc position by detecting the drive shaft's rotation angle. However, in high-pressure, high-precision triple-eccentric butterfly valves requiring precise water control, this detection method can lead to false full-closed states due to elastic torsional deformation of the valve stem under high torque. Even though the actuator has rotated to the fully closed position and the sensor provides a signal, the valve disc may not be truly tightly sealed. This slight angular deviation causes insufficient sealing, resulting in persistent internal leakage, long-term erosion of the sealing surface, shortened valve life, and hidden water waste. While existing solutions involving thickening the valve stem can reduce deformation, they are costly, heavy, and cannot completely eliminate torsion. Accuracy remains limited by the valve stem's length-to-diameter ratio, offering only a temporary solution.
[0003] To address the aforementioned issues, existing technologies offer several solutions. For example, increasing the cross-sectional area of the valve stem to enhance torsional stiffness attempts to reduce detection errors by decreasing physical strain. However, this significantly increases material costs and overall weight, and because strain cannot be completely eliminated, detection accuracy remains limited by the valve stem's length-to-diameter ratio. Another approach involves introducing a high-precision electronic differential pressure gauge to indirectly estimate the degree of closure by monitoring the pressure gradient before and after the valve. While this method avoids mechanical errors, the reliability of electronic components is far lower than that of purely mechanical structures under complex conditions such as underground installations, damp environments, or strong vibrations, and it cannot be directly used as a physical alarm signal source.
[0004] Therefore, there is an urgent need for a mechanical sensing alarm mechanism for abnormal valve opening. This mechanism should be able to detect the difference in displacement between the two ends of the valve stem, bypassing the interference of valve stem torsional deformation, and directly capture the true sealing state of the valve disc to provide an immediate alarm, thereby providing zero-leakage water-saving protection for the pipeline system. Summary of the Invention
[0005] The purpose of this invention is to provide a mechanical sensing alarm mechanism for abnormal valve opening, so as to solve the problem that the existing valve opening monitoring method causes the detection benchmark deviation due to the elastic torsional deformation of the valve stem, thereby causing false full closure and continuous internal leakage of the medium.
[0006] To achieve the above objectives, the present invention provides the following technical solution: A mechanical sensing alarm mechanism for abnormal valve opening is disclosed, applied to a valve. The valve includes a valve body, a valve disc, a valve stem, and an actuator. The valve disc is installed in the valve body. The valve stem is rotatably engaged with the valve body and fixedly connected to the valve disc. The upper end of the valve stem is connected to the actuator. A detection through-hole is coaxially formed inside the valve stem. A detection rod is rotatably connected inside the detection through-hole. The upper end of the detection rod is fixedly connected to the upper end of the valve stem. The lower end of the detection rod extends outside the valve stem. A compression block is slidably connected to the lower end of the detection rod. A compression ring is installed on the lower end face of the valve stem. The upper end face of the compression block and the lower end face of the compression ring are wedge-shaped and slidably engaged. A mechanism is formed inside the valve body that... The valve stem has a coaxial detection chamber, and the outer wall of the extrusion block is slidably connected to the detection chamber. An alarm is installed on the valve body, and a trigger assembly is also provided on the valve body. The trigger assembly is drivenly connected to the alarm and communicates with the detection chamber. This design converts the angular displacement difference between the driving end and the valve disc end caused by the elastic torsional deformation of the valve stem into the axial displacement of the extrusion block. This axial displacement causes a change in pressure within the detection chamber, which in turn drives the purely mechanical alarm through the trigger assembly. This design directly bypasses the interference of valve stem torsional deformation on the detection reference, achieving differential detection of the true sealing position of the valve disc. It avoids the false full closure phenomenon in existing technologies where the drive is in place but the valve disc is not closed, eliminating continuous internal leakage of media caused by detection blind spots. Furthermore, this mechanism uses purely mechanical transmission and pressure transmission, requiring no electronic components, ensuring reliability under complex operating conditions.
[0007] Preferably, the triggering assembly includes a trigger cylinder, a trigger piston, and a trigger spring. The trigger cylinder has a trigger chamber that communicates with a detection chamber. The trigger piston is slidably connected within the trigger chamber. The trigger spring is coaxially mounted within the trigger cylinder, with its two ends connected to the trigger piston and the inner wall of the trigger cylinder, respectively. The effective pressure-bearing area of the trigger piston is greater than the effective pressure-bearing area of the lower end face of the extrusion block. The detection chamber and the trigger chamber are filled with a pressure transmission medium. The valve body has a pressure transmission medium filling port. By setting a trigger cylinder, a trigger piston, and a trigger spring within the valve body, and connecting the trigger chamber with the detection chamber, while designing the effective pressure-bearing area of the trigger piston to be greater than the effective pressure-bearing area of the lower end face of the extrusion block, the small pressure generated by the extrusion block is amplified into a driving force sufficient to push the trigger piston by utilizing the area difference. This solves the problem that the pressure change caused by the slight torsional deformation of the valve stem is insufficient to reliably trigger the alarm, avoiding the hidden danger of insufficient alarm sensitivity or inability to operate. In addition, the pressure transmission medium is filled into the detection chamber and the trigger chamber and a filling port is provided to ensure the continuity and stability of pressure transmission and avoid response delay or failure caused by medium deficiency or air bubbles. The trigger spring ensures that the piston can automatically reset after the pressure is released, so that the alarm mechanism has the ability to be reused. This ensures the high sensitivity, high reliability, reusability and long-term maintenance-free performance of the mechanical induction alarm mechanism for abnormal valve opening.
[0008] Preferably, the alarm is a spring-loaded energy storage type alarm, comprising a spiral spring barrel, an escapement gear train, a locking sear, and an alarm bell. The spiral spring barrel can store energy in advance, and its output end is connected to the escapement gear train. The middle part of the locking sear is rotatably connected to the valve body. One end of the locking sear is connected to the escapement gear train, and the other end is connected to the valve body via a locking spring. The end of the trigger piston is connected to the side of the locking sear away from the locking spring. The output end of the escapement gear train is connected to the alarm bell. This solution stores mechanical energy in advance through the spiral spring barrel and utilizes the cooperation between the escapement gear train and the locking sear, so that the trigger piston only needs to overcome a small force from the locking spring to release the spring energy to drive the alarm bell. This avoids the problem of easy failure of relying on external power sources or electronic components in harsh working conditions such as underground, humid, and strong vibration, and also solves the contradiction of excessive force required to directly drive the alarm bell and insufficient trigger sensitivity. The interlocking design of the locking stopper and the trigger piston ensures that once the alarm signal is triggered, the alarm bell will irreversibly continue to ring, avoiding the risk of missed alarms due to the elastic rebound of the valve stem. The escapement gear system controls the release of the spring energy at a set rate, enabling the alarm bell to emit a stable and persistent acoustic alarm signal. This guarantees the mechanism's instantaneous response, high trigger sensitivity, alarm self-holding, and long-term reliable physical signal output performance even without external power supply.
[0009] Preferably, a throttling damping channel is provided within the valve body. Both ends of the throttling damping channel are connected to the trigger chamber and the detection chamber. An adjusting screw is rotatably connected to the valve body, and the end of the adjusting screw is tapered, allowing it to be screwed into the throttling damping channel. This design, by providing a throttling damping channel connecting the trigger chamber and the detection chamber and using a tapered adjusting screw to adjust the flow cross-sectional area, controls the flow velocity of the pressure transmission medium between the chambers. This design avoids instantaneous pressure spikes caused by rapid valve opening and closing, water hammer pressure fluctuations, or actuator impacts directly acting on the trigger piston, preventing false alarms and mechanical impact damage caused by these problems. Simultaneously, the adjustable damping function suppresses piston reciprocating vibrations caused by pressure fluctuations, solving the problem of unstable alarm signals or repeated triggering caused by fluid disturbances. By rotating the adjusting screw to change the damping magnitude, it is also possible to compensate for changes in characteristics due to different medium viscosities, different valve specifications, and long-term wear, allowing the trigger sensitivity and response speed to be calibrated according to actual working conditions. This ensures the mechanical sensing alarm mechanism's shock resistance, smooth operation, resistance to false triggering, and adaptability to a wide range of operating conditions under complex dynamic hydraulic conditions.
[0010] Preferably, the trigger cylinder has a threaded hole at the end near the alarm, and a limit screw is screwed into the threaded hole, with one end of the limit screw extending into the trigger cylinder. This design, by providing a threaded hole at the end of the trigger cylinder near the alarm and screwing in a limit screw, allows one end of the limit screw to extend into the trigger cylinder, forming an adjustable mechanical limit structure. This design avoids damage to the alarm linkage mechanism due to excessive travel caused by excessive trigger piston stroke, and also solves the sensitivity inaccuracy problem caused by manufacturing tolerances, long-term wear, or fixed and unadjustable trigger thresholds for different valve specifications. By rotating the limit screw to change its extension length, the maximum movement distance of the trigger piston can be precisely set, thereby calibrating and adjusting the alarm trigger angle difference under field conditions, enabling the alarm mechanism to adapt to different sealing specific pressures, different valve stem stiffnesses, and different media conditions. This ensures the adjustable trigger accuracy, reliable stroke limit, overload protection capability, and broad engineering adaptability of the mechanical induction alarm mechanism.
[0011] Preferably, the valve body has a connecting hole and a visual glass tube. The visual glass tube is arranged vertically, with its upper end closed and its lower end connected to the detection chamber through the connecting hole. This design, by using a vertically arranged visual glass tube on the valve body, connecting its lower end to the detection chamber through the connecting hole, and closing its upper end, allows the pressure transmission medium in the detection chamber to enter the glass tube and form a liquid column. The height of the liquid column rises and falls with changes in the pressure in the detection chamber, thus converting the displacement of the squeeze block corresponding to the valve stem torsion angle difference into a direct liquid level indication. This avoids the problem that on-site inspectors cannot quickly determine whether the alarm threshold has drifted, whether the medium has leaked, or whether the mechanism is working properly due to the lack of visibility of the internal state of the mechanism. It also solves the problem that relying on electronic instrument readings is easily interfered with or unusable in humid or explosion-proof environments. This ensures the on-site observability, inspection convenience, self-diagnostic capability, and explosion-proof environment adaptability of the mechanical induction alarm mechanism under conditions without external power supply.
[0012] Preferably, the visual glass tube has axial graduations on its wall, a float plate inside the tube with a density less than that of the medium filling it, and a buffer cavity at its upper end. This design allows inspectors to directly read the liquid level by setting axial graduations on the tube wall, enabling them to accurately determine whether pressure changes and valve stem torsion angle differences within the detection chamber have reached alarm thresholds. This avoids the delays and uncertainties associated with relying solely on experience or alarm activation. The float plate, with a density less than that of the medium, makes the liquid level indicator more prominent, preventing the difficulty in distinguishing the liquid level in low-light or long-distance observations of colorless, transparent media. The buffer cavity at the upper end of the tube allows the float plate to decelerate and stop when it enters the cavity and loses buoyancy, preventing damage or jamming caused by high-speed impacts on the top of the glass tube. This ensures the visibility of the mechanical sensing alarm mechanism during on-site inspections, the intuitive accuracy of readings, the identifiability under low light conditions, and the long-term operational reliability under pressure transient conditions.
[0013] Preferably, the upper end face of the extrusion block and the lower end face of the extrusion ring are provided with sliding surfaces, which are polished. This design reduces the surface roughness and friction coefficient of the wedge-shaped sliding mating surface by providing sliding surfaces on the upper end face of the extrusion block and the lower end face of the extrusion ring, and polishing these sliding surfaces. This design avoids problems such as sluggish axial movement, jamming, or discontinuous movement of the extrusion block due to excessive frictional resistance of the sliding surface. It also eliminates abnormal wear caused by surface roughness and prevents trigger threshold drift and sensitivity reduction caused by changes in the wedge surface size after long-term use. This ensures the smoothness of the relative movement between the extrusion block and the extrusion ring, the timeliness of the action response, and the durability and consistent triggering accuracy of the entire mechanical induction alarm mechanism under long-term reciprocating conditions.
[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention uses a detection rod with its upper end fixedly connected to the upper end of the valve stem and its lower end slidably connected to a compression block. A compression ring is fixed to the lower end of the valve stem, creating a wedge-shaped sliding fit between the compression block and the compression ring. This converts the angular displacement difference between the driving end and the valve plate end caused by the elastic torsional deformation of the valve stem into the axial displacement of the compression block, thereby changing the pressure in the detection chamber and triggering an alarm. This differential detection mechanism bypasses the interference of valve stem torsional deformation on the detection reference, solves the problem of false full closure in existing technologies where the drive is in place but the valve plate is not closed, eliminates persistent internal leakage of the medium, and provides zero-leakage protection for the pipeline system.
[0015] 2. This invention employs a hydraulic amplification structure where the effective pressure-bearing area of the trigger piston is greater than the effective pressure-bearing area of the lower end face of the extrusion block. This amplifies the extrusion force generated by the slight torsional angle difference of the valve stem several times, ensuring reliable triggering of the spring-loaded energy storage alarm. Simultaneously, the throttling damping channel, in conjunction with the conical adjusting screw, can suppress false triggering caused by water hammer impact and pressure fluctuations, and the trigger sensitivity can be calibrated on-site. Compared with existing solutions that rely on electronic differential pressure gauges or simply thicken the valve stem, this invention achieves reliable capture and anti-interference adjustment of weak signals while maintaining high reliability of purely mechanical components.
[0016] 3. This invention employs a spring-loaded energy storage alarm with an adjustable mechanical limit structure. The spiral spring box pre-stores energy, and the trigger piston only needs to overcome a small force from the locking spring to release the spring and drive the alarm bell to ring continuously, achieving alarm self-holding and preventing missed alarms caused by valve stem rebound. The limit screw can precisely set the maximum piston stroke to prevent overload damage to the alarm linkage mechanism. Compared with existing instantaneous pulse electrical alarms or mechanical detection devices without audible and visual indications, this invention can output a persistent and clear physical alarm signal without external power supply, and the trigger threshold is adjustable to adapt to different valve specifications and operating conditions. Attached Figure Description
[0017] Figure 1This is a schematic diagram of the mechanical sensing alarm mechanism for abnormal valve opening according to the present invention; Figure 2 For the present invention Figure 1 Sectional view at point AA; Figure 3 This is a diagram showing the normal working state of the mechanical sensing alarm mechanism for abnormal valve opening in this invention. Figure 4 This is a state diagram of the mechanical sensing alarm mechanism for abnormal valve opening in this invention when an alarm is triggered. Figure 5 This is a schematic diagram of the installation of the squeezing block and squeezing ring in the mechanical sensing alarm mechanism for abnormal valve opening of the present invention.
[0018] In the diagram: 1. Valve body; 2. Valve disc; 3. Valve stem; 4. Actuator; 501. Detection through hole; 502. Detection rod; 503. Extrusion block; 504. Extrusion ring; 505. Detection chamber; 506. Sliding surface; 601. Trigger cylinder; 602. Trigger piston; 603. Trigger spring; 604. Trigger chamber; 605. Filling port; 7. Alarm; 701. Scroll spring barrel; 702. Escapement gear train; 703. Locking sear; 704. Locking spring; 705. Alarm bell; 801. Throttling damping channel; 802. Adjusting screw; 803. Threaded hole; 804. Limit screw; 901. Connecting hole; 902. Visual glass tube; 903. Float; 904. Buffer cavity. Detailed Implementation
[0019] Please see Figures 1 to 5 This invention provides a mechanical sensing alarm mechanism for abnormal valve opening, the technical solution of which is as follows: Please refer to a mechanical sensing alarm mechanism for abnormal valve opening. Figures 1 to 5This system is applied to valves, which include a valve body 1, a valve disc 2, a valve stem 3, and an actuator 4. The valve disc 2 is installed inside the valve body 1. The valve stem 3 is rotatably connected to the valve body 1 and is fixedly connected to the valve disc 2. The upper end of the valve stem 3 is connected to the actuator 4. A detection through hole 501 is coaxially opened inside the valve stem 3. A detection rod 502 is rotatably connected inside the detection through hole 501. The upper end of the detection rod 502 is fixedly connected to the upper end of the valve stem 3, and the lower end of the detection rod 502 extends outside the valve stem 3. A pressing block 503 is slidably connected to the lower end of the detection rod 502. A pressing ring 504 is installed on the lower end face of the valve stem 3. The upper end face of the pressing block 503 and the lower end face of the pressing ring 504 are wedge-shaped slidingly engaged. A detection cavity 505 coaxial with the valve stem 3 is opened inside the valve body 1. The pressing block 503... The outer wall of the valve body 1 is slidably connected to the detection chamber 505. An alarm 7 is installed on the valve body 1. The valve body 1 is also equipped with a trigger assembly, which includes a trigger cylinder 601, a trigger piston 602, and a trigger spring 603. The trigger cylinder 601 has a trigger chamber 604, which is connected to the detection chamber 505. The trigger piston 602 is slidably connected to the trigger chamber 604. The trigger spring 603 is coaxially installed in the trigger cylinder 601. The two ends of the trigger spring 603 are respectively connected to the trigger piston 602 and the inner wall of the trigger cylinder 601. The effective pressure bearing area of the trigger piston 602 is greater than the effective pressure bearing area of the lower end face of the extrusion block 503. The detection chamber 505 and the trigger chamber 604 are filled with a pressure transmission medium. The valve body 1 has a pressure transmission medium filling port 60. 5. The alarm 7 is a spring-loaded alarm 7, which includes a spiral spring barrel 701, an escapement gear train 702, a locking sear 703, and an alarm bell 705. The spiral spring barrel 701 can store energy in advance. The output end of the spiral spring barrel 701 is connected to the escapement gear train 702. The middle part of the locking sear 703 is rotatably connected to the valve body 1. One end of the locking sear 703 is connected to the escapement gear train 702, and the other end is connected to the valve body 1 by a locking spring 704. The end of the trigger piston 602 is connected to the side of the locking sear 703 away from the locking spring 704. The output end of the escapement gear train 702 is connected to the alarm bell 705. The end of the trigger piston 601 near the alarm 7 has a threaded hole 803. A limiting screw 804 is internally engaged, with one end of the limiting screw 804 extending into the trigger cylinder 601. A throttling damping channel 801 is provided inside the valve body 1, with both ends of the throttling damping channel 801 communicating with the trigger chamber 604 and the detection chamber 505. An adjusting screw 802 is rotatably connected to the valve body 1, with the end of the adjusting screw 802 being tapered and capable of being screwed into the throttling damping channel 801. A connecting hole 901 is provided on the valve body 1, and a visual glass tube 902 is also provided on the valve body 1. The visual glass tube 902 is arranged vertically, with its upper end closed and its lower end communicating with the detection chamber 505 through the connecting hole 901. Scale markings are provided axially on the wall of the visual glass tube 902.The visualization glass tube 902 contains a float plate 903, the density of which is less than the density of the medium filling the visualization glass tube 902. A buffer cavity 904 is also provided at the upper end of the visualization glass tube 902. A sliding surface 506 is provided on the upper end face of the extrusion block 503 and the lower end face of the extrusion ring 504. The sliding surface 506 is polished.
[0020] When working, please refer to Figures 1 to 5When an abnormal opening occurs during valve closure, the valve stem 3 undergoes torsional deformation due to its own elasticity. This causes the actuator 4 drive end to rotate to the fully closed angle, while the valve disc 2 end has not yet reached the sealing position. At this time, an angular displacement difference will occur between the drive end and the valve disc 2 end. The detection rod 502, which is fixedly connected to the drive end, rotates with the drive end. The lower end of the detection rod 502 drives the extrusion block 503 to rotate synchronously through a circumferentially fixed and axially sliding connection. The extrusion ring 504, which is fixed to the valve disc 2 end, maintains a position synchronous with the valve disc 2. The extrusion block 503 and the wedge-shaped sliding surface 506 of the extrusion ring 504 rotate relative to each other. Under the action of the wedge-shaped inclined surface, the extrusion block 503 slides downward along the axial direction of the detection rod 502, extruding the pressure transmission medium in the detection chamber 505, causing the pressure in the detection chamber 505 to increase. The increased pressure is transmitted to the trigger chamber 604 through the connecting pipe and acts on the trigger piston 602. Since the effective pressure-bearing area of the trigger piston 602 is greater than the effective pressure-bearing area of the lower end face of the squeezing block 503, the pressure transmitted by the squeezing block 503 is amplified. When the pressure rises to the set threshold, it pushes the trigger piston 602 to overcome the elastic force of the trigger spring 603 and move towards the alarm 7. During the movement of the trigger piston 602, it pushes the locking stop 703 to rotate, causing the locking stop 703 to disengage from the escapement transmission gear system 702. The mechanical energy pre-stored in the spiral spring box 701 is released and drives the alarm bell 705 to rotate at a set rate through the escapement transmission gear system 702, continuously emitting a stable acoustic alarm signal to remind the on-site operator that the valve is not closed properly and there is an abnormal opening fault. Once the fault is cleared and the angular displacement difference of valve stem 3 is eliminated, the squeezing block 503 moves axially back under the retraction action of the wedge-shaped inclined plane, the pressure in the detection chamber 505 decreases, the trigger piston 602 resets under the action of the trigger spring 603, and the locking stop 703 relocks the escapement transmission gear train 702 under the action of the locking spring 704, waiting for the next abnormal operating condition trigger. During the inspection, the operator can also directly observe the liquid level height of the float 903 in the visualization glass tube 902, and directly read the pressure value of the detection chamber 505 by referring to the scale markings on the tube wall, predict the torsional state of valve stem 3 in advance, and determine whether the mechanism is operating normally. The condition diagnosis can be completed without disassembling the mechanism. When it is necessary to adjust the trigger sensitivity according to the actual operating conditions, the flow area of the throttling damping channel 801 can be changed by rotating the adjusting screw 802 to adjust the pressure response speed. Alternatively, the maximum allowable stroke of the trigger piston 602 can be changed by rotating the limiting screw 804, thereby calibrating the angular displacement difference threshold for alarm triggering. The two methods work together to adapt to different valve specifications and media conditions.
[0021] The specific embodiment of the present invention has been described in detail above with reference to the accompanying drawings, but the present invention is not limited to the embodiments described above. For those skilled in the art, various changes, modifications, substitutions, and variations made to these embodiments without departing from the principles and ideas of the present invention should still fall within the protection scope of the present invention.
Claims
1. A mechanical sensing alarm mechanism for abnormal valve opening, characterized in that, This invention relates to a valve, which includes a valve body (1), a valve disc (2), a valve stem (3), and an actuator (4). The valve disc (2) is installed inside the valve body (1). The valve stem (3) is rotatably connected to the valve body (1). The valve stem (3) is fixedly connected to the valve disc (2). The upper end of the valve stem (3) is connected to the actuator (4). A detection through hole (501) is coaxially opened inside the valve stem (3). A detection rod (502) is rotatably connected inside the detection through hole (501). The upper end of the detection rod (502) is fixedly connected to the upper end of the valve stem (3). The lower end of the detection rod (502) extends outside the valve stem (3). The lower end of the measuring rod (502) is slidably connected to a squeezing block (503), and a squeezing ring (504) is installed on the lower end face of the valve stem (3). The upper end face of the squeezing block (503) and the lower end face of the squeezing ring (504) are wedge-shaped sliding fits. A detection cavity (505) coaxial with the valve stem (3) is opened in the valve body (1). The outer side wall of the squeezing block (503) is slidably connected in the detection cavity (505). An alarm (7) is installed on the valve body (1). A triggering component is also provided on the valve body (1). The triggering component is drivenly connected to the alarm (7). The triggering component is connected to the detection cavity (505).
2. The mechanical sensing alarm mechanism for abnormal valve opening according to claim 1, characterized in that: The triggering assembly includes a trigger cylinder (601), a trigger piston (602), and a trigger spring (603). The trigger cylinder (601) has a trigger chamber (604) inside, which is connected to the detection chamber (505). The trigger piston (602) is slidably connected inside the trigger chamber (604). The trigger spring (603) is coaxially installed inside the trigger cylinder (601). The two ends of the trigger spring (603) are respectively connected to the inner wall of the trigger piston (602) and the trigger cylinder (601). The effective pressure-bearing area of the trigger piston (602) is greater than the effective pressure-bearing area of the lower end face of the extrusion block (503). The detection chamber (505) and the trigger chamber (604) are filled with pressure transmission medium. The valve body (1) has a pressure transmission medium filling port (605).
3. The mechanical sensing alarm mechanism for abnormal valve opening according to claim 2, characterized in that: The alarm (7) is a spring-loaded energy storage type alarm (7). The alarm (7) includes a spiral spring box (701), an escapement gear train (702), a locking stop (703), and an alarm bell (705). The spiral spring box (701) can store energy in advance. The output end of the spiral spring box (701) is connected to the escapement gear train (702). The middle part of the locking stop (703) is rotatably connected to the valve body (1). One end of the locking stop (703) is connected to the escapement gear train (702), and the other end is connected to the valve body (1) with a locking spring (704). The end of the trigger piston (602) is connected to the side of the locking stop (703) away from the locking spring (704). The output end of the escapement gear train (702) is connected to the alarm bell (705).
4. The mechanical sensing alarm mechanism for abnormal valve opening according to claim 2, characterized in that: The valve body (1) is provided with a throttling damping channel (801). The two ends of the throttling damping channel (801) are connected to the trigger chamber (604) and the detection chamber (505). An adjusting screw (802) is rotatably connected to the valve body (1). The end of the adjusting screw (802) is conical and can be screwed into the throttling damping channel (801).
5. The mechanical sensing alarm mechanism for abnormal valve opening according to claim 3, characterized in that: The trigger cylinder (601) has a threaded hole (803) at one end near the alarm (7), and a limit screw (804) is screwed into the threaded hole (803), with one end of the limit screw (804) extending into the trigger cylinder (601).
6. The mechanical sensing alarm mechanism for abnormal valve opening according to claim 2, characterized in that: The valve body (1) is provided with a connecting hole (901) and a visual glass tube (902) is also provided on the valve body (1). The visual glass tube (902) is arranged in a vertical direction. The upper end of the visual glass tube (902) is closed, and the lower end of the visual glass tube (902) is connected to the detection chamber (505) through the connecting hole (901).
7. The mechanical sensing alarm mechanism for abnormal valve opening according to claim 6, characterized in that: The wall of the visualization glass tube (902) is marked with graduation marks along the axial direction. A float plate (903) is provided inside the visualization glass tube (902). The density of the float plate (903) is less than the density of the medium filling the visualization glass tube (902). A buffer cavity (904) is also provided at the upper end of the visualization glass tube (902).
8. The mechanical sensing alarm mechanism for abnormal valve opening according to claim 1, characterized in that: The upper end face of the extrusion block (503) and the lower end face of the extrusion ring (504) are provided with sliding surfaces (506), and the sliding surfaces (506) are polished.