Variable-diameter resistance-adjusting fluid pressure detection device

Abstract

The present application relates to a kind of variable-diameter regulation resistance fluid pressure detection device. Including detection box, strain pressure sensor, venturi, venturi opening and closing mechanism, piston mechanism and filter screen opening and closing mechanism. Can utilize the pressure change when filter screen is blocked to drive piston movement, in turn drive venturi to open and drive filter screen to open certain angle, utilize the negative pressure generated in the throat of venturi when water flow enters venturi to suck the silt on filter screen, automatically clean filter screen, the pressure in filter screen is restored after unblocking, piston resets to automatically drive filter screen to reset and close venturi. With the advantage of automatically completing filter screen cleaning without manual cleaning.

Description

TECHNICAL FIELD

[0001] The present application relates to a variable-diameter adjustable resistance fluid pressure detection device. BACKGROUND

[0002] The Yellow River is one of the rivers with the highest sediment concentration in the world. Its dam is threatened by sediment accumulation and water erosion for a long time, which significantly increases the risk of dam break. In order to ensure the stability of the dam, it is necessary to monitor the pressure change inside the dam in real time. Strain pressure sensor is widely used in seepage pressure monitoring due to its high sensitivity and reliability. Such sensors can detect the pressure difference between the inside and outside of the dam, and can provide early warning of hidden dangers such as piping and leakage, which is the core data source for flood control decision-making.

[0003] The water inlet of the traditional strain pressure sensor usually uses a metal filter screen or a fiber filter layer to prevent sediment from entering the sensor cavity. However, in the high-sediment environment of the Yellow River, the filter screen may have the following problems:

[0004] Physical blockage: sediment particles (particle size 0.05-2mm) accumulate on the surface of the filter screen, causing a decrease in porosity and distortion of pressure transmission;

[0005] Maintenance difficulty: the sensor is installed in the deep inside wall of the dam, and manual dredging requires stopping monitoring and disassembling the equipment, which is time-consuming and costly.

[0006] Existing solutions (such as increasing the filter screen aperture or using multiple layers of filtration) can delay clogging, but cannot avoid it. After clogging, manual cleaning is still required, and the pressure detection accuracy is also sacrificed. SUMMARY

[0007] Therefore, the purpose of the present application is to provide a variable-diameter adjustable resistance fluid pressure detection device that can use the pressure change when the filter screen is clogged to drive the piston to move, and then drive the Venturi tube to open and drive the filter screen to open a certain angle. The negative pressure generated by the water flow entering the Venturi tube at its throat can suck the sediment on the filter screen, automatically clean the filter screen, and restore the internal pressure of the filter screen after the filter screen is unblocked. The piston is reset to automatically reset the filter screen and close the Venturi tube.

[0008] The technical solution of the present application is as follows: a variable-diameter adjustable resistance fluid pressure detection device comprises:

[0009] A detection box body is used to be installed and fixed on the inner wall of the dam, and has an opening, and a rigid filter screen is arranged at the opening;

[0010] A strain pressure sensor is installed on the inner wall of one side of the detection box body;

[0011] The Venturi tube comprises a main pipe arranged along the water flow direction, the main pipe comprises an inlet section, a contraction section, a throat and a diffusion section connected in sequence, a suction pipe is vertically connected to the throat of the main pipe, and the inlet of the suction pipe corresponds to the outer surface of the rigid filter screen;

[0012] The piston mechanism is vertically installed on the outside wall of the side of the detection box facing the water flow direction, and comprises a piston cylinder, a piston, a piston rod and a spring. The rodless cavity of the piston is in communication with the inside of the detection box. The spring is sleeved on the piston rod and abuts against the piston and the piston cylinder respectively to provide elastic force to the piston in the direction of the rodless cavity. The rear end of the piston rod penetrates out of the piston cylinder, and a through long hole with a length extending along the axial direction of the piston rod is arranged on the rear end of the piston rod.

[0013] The Venturi tube opening and closing mechanism comprises a lever and a hinged fulcrum. The front end of the lever is provided with an elastic sealing ball for sealing cooperation with the inlet section. The rear end of the lever is slidingly assembled in the through long hole. The piston rod can drive the lever to rotate around the hinged fulcrum to open and close the inlet section after moving a certain distance.

[0014] The filter screen opening and closing mechanism comprises a connecting rod. One end of the connecting rod is hinged to the rear end of the lever, and the other end is hinged to the side of the rigid filter screen facing the water flow direction. The side of the rigid filter screen away from the water flow direction is hinged to the corresponding edge of the opening of the detection box. The side of the rigid filter screen facing the water flow direction is connected to the corresponding edge of the opening of the detection box through a flexible filter screen.

[0015] On the basis of the above-mentioned scheme, the Venturi tube is inclined to be arranged so that when the rigid filter screen rotates to open to the limit position around the hinged point thereof, the axis of the suction pipe is perpendicular to the outer surface of the rigid filter screen. Such design can have higher fit with the rigid filter screen after being opened and inclined, so as to make the suction efficiency higher, and the suction force on each part of the outer surface of the rigid filter screen is basically uniform, so that the suction is more uniform.

[0016] On the basis of the above-mentioned scheme, the connecting rod is an elastic connecting rod, and the length thereof can be adjusted along the axial direction. The connecting rod is arranged as an elastic connecting rod to avoid dead points and jamming.

[0017] On the basis of the above-mentioned scheme, the inlet of the suction pipe is provided with a trumpet mouth. The coverage of the suction can be increased.

[0018] On the basis of the above-mentioned scheme, the inlet of the inlet section has a trumpet mouth, and the elastic sealing ball is in contact with the trumpet mouth to realize the sealing closing of the inlet section. The inner tapered surface of the trumpet mouth can better cooperate with the spherical surface of the elastic sealing ball to realize better sealing.

[0019] On the basis of the above-mentioned scheme, the strain pressure sensor comprises a pressure-sensitive diaphragm and a strain resistance.

[0020] On the basis of the above-mentioned scheme, further improvements are as follows: the outer circumferential surface of the piston is inlaid with an elastic sealing ring to be in sliding sealing cooperation with the inner wall of the piston cylinder.

[0021] On the basis of the above-mentioned scheme, further improvements are as follows: the fixed frame is fixed relative to the detection box body, the Venturi tube is fixed on the fixed frame, and the lever is hinged on the fixed frame through the hinged fulcrum.

[0022] On the basis of the above-mentioned scheme, further improvements are as follows: the elastic sealing ball is a hollow ball, the front end of the lever has a circular plate, and the elastic sealing ball is connected to the circular plate. The hollow ball can reduce the weight of the elastic sealing ball, thereby reducing the required driving force.

[0023] The beneficial effects of this invention: When the fluid pressure detection device of this invention, which adjusts resistance by changing diameter, is in use, as sediment gradually accumulates on the outer surface of the filter screen, causing the rigid filter screen to become clogged, the detection chamber is isolated from the external water pressure. The pressure inside the detection chamber decreases, and the compressed spring pushes the piston towards the rodless chamber. After the piston rod moves a certain distance, its sidewall through the elongated hole contacts the rear end of the lever, causing the lever to rotate around its hinge point. This causes the elastic sealing ball at its front end to move, thereby opening the inlet section of the Venturi tube. River water then enters the Venturi tube and flows sequentially through the contraction section, throat, and diffuser section. Due to the Venturi effect, a vacuum suction is generated at the throat, which is transmitted to the outer surface of the rigid filter screen through the suction pipe. Simultaneously, the rotation of the lever also drives the connecting rod to rotate and move, thereby pushing the rigid filter screen to rotate around its hinge point. The side of the rigid filter screen facing the water flow opens, and the folded flexible filter screen gradually unfolds. The flexible filter screen then performs a filtering function, preventing sediment from entering the detection chamber through the opening of the rigid filter screen. More importantly, because the flexible filter screen was previously folded and not clogged, the detection chamber, which was originally sealed due to the blockage of the rigid filter screen, partially reopens. When the detection chamber is no longer sealed, the silt inside the rigid filter screen is more easily extracted when it is subjected to the suction force of the suction tube. As the silt inside the rigid filter screen is gradually extracted, the cross-section between the rigid filter screen and the outside gradually increases, and the water pressure transmitted into the detection chamber gradually increases. The water pressure gradually overcomes the elastic force of the spring and pushes the piston towards the rod chamber, compressing the spring. The piston rod drives the lever to rotate, gradually causing the elastic sealing ball to close the inlet of the inlet section. At the same time, it causes the rigid filter screen to rotate in the opposite direction around its hinge point, and the flexible filter screen is gradually folded up until the blockage of the rigid filter screen reaches the set threshold again. This set threshold causes the water pressure in the detection tank to drop again to the point where it cannot overcome the elastic force of the spring. The piston then moves towards the rodless chamber again, thus starting the next silt extraction and cleaning cycle, forming an automatic cycle of cleaning silt from the rigid filter screen. Therefore, the technical solution of this application can automatically clean the rigid filter screen at the opening of the detection chamber, avoiding long-term clogging of the filter screen and preventing the strain gauge pressure sensor inside the detection chamber from malfunctioning, thus ensuring the safety of dam breach monitoring. Compared to existing technologies, this application eliminates the need for manual filter screen cleaning. Instead, it utilizes the water flow and the variable diameter of the venturi tube to adjust resistance and create a vacuum suction in the throat. When the filter screen becomes clogged, the pressure change automatically opens the venturi tube to clean the screen, creating a clever cycle that eliminates the need for manual cleaning. Furthermore, the design of the rigid filter screen opening towards the water flow side allows some water to pass through the flexible filter screen and then flush the rigid filter screen outwards from inside the detection chamber, further helping to remove sediment from the rigid filter screen.Furthermore, since the through-hole has a certain length, when the piston rod moves inside the through-hole and does not contact the side walls on the left and right sides of the through-hole, there is no cooperation between them, and the lever will not rotate. The purpose of this setting is mainly to ensure that the venturi tube only works when it is necessary to clean mud and sand, thereby minimizing the impact of the opening of the venturi tube on the pressure inside the detection chamber, which may interfere with the normal detection of the strain gauge pressure sensor. Attached Figure Description

[0024] Figure 1 This is a schematic diagram (non-operating state) of an embodiment of a fluid pressure detection device for adjusting resistance by varying diameter according to the present invention.

[0025] Figure 2 for Figure 1 A magnified view of a section at point A in the middle;

[0026] Figure 3 for Figure 1 A structural diagram of the corresponding working state;

[0027] Figure 4 for Figure 3 A magnified view of a section at point B in the middle;

[0028] In the diagram: 1-Dyke, 2-Detection box, 21-Opening, 22-Rigid filter, 23-Flexible filter, 24-Strain gauge pressure sensor, 241-Pressure diaphragm, 242-Strain gauge resistor, 25-Side wall facing the water flow, 251-Connecting port, 26-Side wall away from the water flow, 3-Venturi tube, 31-Flare mouth, 32-Inlet section, 33-Contraction section, 34-Throat, 35-Diffuser section, 36 - Suction tube, 4- Piston mechanism, 41- Piston cylinder, 411- Rodless chamber, 412- Rod chamber, 42- Piston, 421- Elastic sealing ring, 43- Piston rod, 431- Through hole, 44- Spring, 5- Venturi tube opening and closing mechanism, 51- Lever, 511- Circular plate, 52- Hinge fulcrum, 53- Elastic sealing ball, 6- Filter screen opening and closing mechanism, 61- Connecting rod, 7- Hinge shaft, 8- Sediment. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention; that is, the described embodiments are merely some embodiments of the invention, and not all embodiments. The components of the embodiments of the invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0030] Therefore, the following detailed description of the embodiments of the 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 invention without inventive effort are within the scope of protection of the invention.

[0031] It should be noted that relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0032] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0033] A specific embodiment of the fluid pressure detection device for variable diameter adjustment resistance according to the present invention: taking the Yellow River detection as an example, as follows... Figure 1 As shown, the fluid pressure detection device for variable diameter adjustment resistance mainly includes a detection chamber 2, a strain gauge pressure sensor 24, a venturi tube 3, a venturi tube opening and closing mechanism 5, a piston mechanism 4, and a filter opening and closing mechanism 6.

[0034] Specifically, such as Figures 1-2 As shown, the detection box 2 is a stainless steel square box. Its bottom plate, away from the opening 21, is fixedly installed on the inner wall of the dam 1 and is located in the river. The water flows from left to right in the figure. The detection box 2 has an opening 21, and a rigid filter screen 22 is provided at the opening 21. The right end of the rigid filter screen 22 is hinged to the right edge of the opening 21 of the detection box 2 through a hinge shaft 7. The left end of the rigid filter screen 22 is hinged to a connecting rod through a hinge shaft 7 and connected to the left edge of the opening 21 of the detection box 2 through a flexible filter screen 23. The rigid filter screen 22 can be made of stainless steel, and the flexible filter screen 23 can be made of plastic or nylon rope, etc.

[0035] like Figure 1 , 2As shown, the strain gauge pressure sensor 24 is installed on one inner wall of the detection chamber 2 (i.e., the side wall 26 facing away from the water flow). It includes a pressure-sensing diaphragm 241 and a strain resistor 242. The strain resistor 242 is connected to other modules through wires to realize functions such as data conversion, analysis, calculation and processing, and wireless transmission. These are existing technologies and will not be described in detail.

[0036] like Figure 1 As shown, the Venturi tube 3 includes a main tube arranged along the river flow direction. The axis of the main tube is basically parallel or completely parallel to the water flow direction. When completely parallel, the angle between the suction tube 36 and the main tube can be changed to maintain the angle shown in the figure. The main tube includes an inlet section 32, a contraction section 33, a throat 34, and a diffuser section 35 connected sequentially along the water flow direction. The suction tube 36 is vertically connected at the throat 34 of the main tube. The inlet of the suction tube 36 is set on the outer surface of the rigid filter screen 22. A bell mouth 31 is provided at both the inlet section 32 and the suction tube 36. The bell mouth 31 at the inlet of the suction tube 36 can increase the suction coverage. The inlet of the inlet section 32 has a bell mouth 31, and the elastic sealing ball 53 contacts and cooperates with the bell mouth 31 to achieve a sealed closure of the inlet section 32. The inner conical surface of the bell mouth 31 can be used to better cooperate with the spherical surface of the elastic sealing ball 53 to achieve a better seal. The venturi tube 3 is tilted so that when the rigid filter 22 is rotated open to its limit position around its hinge point, the axis of the suction tube 36 is perpendicular to the outer surface of the rigid filter 22. This design allows for a higher degree of contact with the tilted rigid filter 22 after it is opened, resulting in higher suction efficiency and more uniform suction force across the outer surface of the rigid filter 22.

[0037] like Figure 2 As shown, the piston mechanism 4 is vertically mounted on the outer wall of the detection chamber 2 facing the water flow direction (i.e., the side wall 25 facing the water flow). The piston mechanism 4 includes a piston cylinder 41, a piston 42, a piston rod 43, and a spring 44. The rodless chamber 411 of the piston 42 is connected to the interior of the detection chamber 2 through a connecting port 251. The spring 44 is sleeved on the piston rod 43 and abuts against the piston 42 and the piston cylinder 41 respectively to provide the piston 42 with an elastic force in the direction of the rodless chamber 411. The rear end of the piston rod 43 passes through the piston cylinder 41, and the rear end of the piston rod 43 is provided with a through hole 431 extending along the axial direction of the piston rod 43. The piston rod 43 can be a square rod. Alternatively, the piston 42 can be a square piston 42, while the piston rod 43 can be circular. An elastic sealing ring 421 is embedded on the outer circumferential surface of the piston 42 to slide and seal with the inner wall of the piston cylinder 41.

[0038] like Figure 1 , 2As shown, the venturi tube opening and closing mechanism 5 includes a lever 51 and a hinge fulcrum 52. The front end of the lever 51 is provided with an elastic sealing ball 53 for sealing with the inlet section 32. The rear end of the lever 51 is slidably fitted into the through-hole 431. After the piston rod 43 moves a certain distance, it can drive the lever 51 to rotate around the hinge fulcrum 52 to open and close the inlet section 32. Since the through-hole 431 has a certain length, when the piston rod 43 moves within the through-hole 431 and does not contact the side walls on the left and right sides of the through-hole 431, there is no engagement between them, and the lever 51 will not rotate. The purpose of this arrangement is mainly to ensure that the venturi tube 3 only works when it needs to be cleaned of mud and sand, thereby minimizing the impact of the opening of the venturi tube 3 on the pressure inside the detection chamber 2, which would interfere with the normal detection of the strain gauge pressure sensor 24. The elastic sealing ball 53 is a hollow sphere, and the front end of the lever 51 has a circular plate 511, on which the elastic sealing ball 53 is connected. The hollow ball reduces the weight of the elastic sealing ball 53, thereby reducing the required driving force.

[0039] like Figure 2 As shown, the filter screen opening and closing mechanism 6 includes a connecting rod 61. One end of the connecting rod 61 is hinged to the rear end of the lever 51, and the other end is hinged to the side of the rigid filter screen 22 facing the water flow direction. The side of the rigid filter screen 22 facing away from the water flow direction is hinged to the edge of the opening 21 of the detection box 2. The side of the rigid filter screen 22 facing the water flow direction and the corresponding edge of the opening 21 of the detection box 2 are connected by a flexible filter screen 23. The connecting rod 61 is an elastic connecting rod 61, and its length can be adjusted axially. For example, an elastic structure formed by compressed gas can be connected in series on the elastic connecting rod 61. Setting the connecting rod 61 as an elastic connecting rod 61 can avoid dead points and jamming.

[0040] The fluid pressure detection device also includes a fixed frame (not shown in the figure), which is fixed relative to the detection box 2. The venturi tube 3 is fixed on the fixed frame, and the lever 51 is hinged to the fixed frame through the hinge fulcrum 52.

[0041] The fluid pressure detection device for variable diameter adjustment resistance of the present invention, when in use, such as... Figures 1-2 As shown, when sediment 8 gradually accumulates on the outer surface of the rigid filter screen 22, causing the rigid filter screen 22 to gradually become clogged, the detection chamber 2 is isolated from the external water pressure, and the pressure inside the detection chamber 2 will decrease. At this time, the compressed spring 44 pushes the piston 42 to move towards the rodless chamber 411. After the piston rod 43 moves a certain distance, as... Figures 3-4As shown, one side wall of the through-hole 431 contacts the rear end of the lever 51, causing the lever 51 to rotate around its hinge fulcrum 52, which in turn moves the elastic sealing ball 53 on its front end, thereby opening the opening 21 of the inlet section 32 of the Venturi tube 3. The river water then enters the Venturi tube 3 and flows sequentially through the contraction section 33, the throat 34, and the diffuser section 35. Due to the Venturi effect, a vacuum suction is generated at the throat, which is transmitted to the outer surface of the rigid filter screen 22 through the suction tube 36. Simultaneously... The rotation of lever 51 also drives the connecting rod 61 to rotate and move, thereby pushing the rigid filter screen 22 to rotate around its hinge point. The side of the rigid filter screen 22 facing the water flow opens, and the folded flexible filter screen 23 gradually unfolds. The flexible filter screen 23 plays a filtering role, preventing sediment 8 from entering the detection chamber 2 through the opening 21 of the rigid filter screen 22. More importantly, because the flexible filter screen 23 was previously in a folded state and was not blocked, the detection chamber 2, which was originally in a sealed state due to the blockage of the rigid filter screen 22, is reopened. When the detection chamber 2, partially opened and no longer sealed, is subjected to the suction force of the suction pipe 36, the sediment 8 trapped within the mesh of the rigid filter 22 is more easily extracted. As the sediment 8 within the mesh of the rigid filter 22 is gradually removed, the cross-section connecting the rigid filter 22 to the outside gradually increases, and the water pressure transmitted to the detection chamber 2 gradually increases. The water pressure gradually overcomes the elastic force of the spring 44, pushing the piston 42 towards the rod chamber 412 and compressing the spring 44. The piston rod 43 then drives the lever 51 to rotate. The movement gradually causes the elastic sealing ball 53 to close the inlet of the inlet section 32, and at the same time drives the rigid filter screen 22 to rotate in the opposite direction around its hinge point. The flexible filter screen 23 is gradually folded up until the degree of blockage of the rigid filter screen 22 reaches the set threshold again. The set threshold causes the water pressure in the detection tank to drop again to the point that it cannot overcome the elastic force of the spring 44. The piston 42 moves toward the rodless chamber 411 again, thus starting the next suction and cleaning of the mud and sand 8, thereby forming a cycle of automatically cleaning the mud and sand 8 on the rigid filter screen 22. Therefore, the technical solution of this application can automatically clean the rigid filter screen 22 at the opening 21 of the detection chamber 2, avoiding long-term clogging of the filter screen and preventing the strain gauge pressure sensor 24 inside the detection chamber 2 from malfunctioning, thus ensuring the safety of dam breach monitoring. Compared with the prior art, this application does not require manual cleaning of the filter screen. Instead, it uses the water flow and the variable diameter of the venturi tube 3 to adjust the resistance to form a vacuum suction in the throat 34. When the filter screen is clogged, the pressure change automatically opens the venturi tube 3 to clean the filter screen, creating a clever cycle that has the advantage of automatically cleaning the filter screen without manual cleaning. In addition, the design of the rigid filter screen 22 opening to the side facing the water flow allows some water to pass through the flexible filter screen 23 and then flush the rigid filter screen 22 from inside the detection chamber 2, which also helps to flush out the mud and sand 8 inside the rigid filter screen 22.

[0042] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. The scope of patent protection of the present invention shall be determined by the claims. Similarly, any equivalent structural changes made based on the description and drawings of the present invention shall also be included within the scope of protection of the present invention.

Claims

1. A fluid pressure detection device with variable diameter and adjustable resistance, comprising: The detection chamber is designed to be installed and fixed on the inner wall of the dam. It has an opening with a rigid filter screen installed at the opening. A strain gauge pressure sensor is installed on the inner wall of one side of the detection chamber; Its characteristic is that it further includes: The Venturi tube includes a main tube arranged along the direction of river flow. The main tube includes an inlet section, a constriction section, a throat and a diffuser section connected in sequence. A suction pipe is vertically connected to the throat of the main tube, and the inlet of the suction pipe is set corresponding to the outer surface of the rigid filter screen. The piston mechanism is vertically installed on the outer side wall of the detection chamber facing the water flow direction. It includes a piston cylinder, a piston, a piston rod, and a spring. The rodless chamber of the piston is connected to the interior of the detection chamber. The spring is sleeved on the piston rod and abuts against the piston and piston cylinder respectively to provide the piston with an elastic force in the direction of the rodless chamber. The rear end of the piston rod passes through the piston cylinder and has a through hole extending along its axial length on the rear end of the piston rod. The venturi tube opening and closing mechanism includes a lever and a hinge fulcrum. The front end of the lever is provided with an elastic sealing ball for sealing with the inlet section. The rear end of the lever is slidably assembled in the through-hole. After the piston rod moves a certain distance, it can drive the lever to rotate around the hinge fulcrum to open and close the inlet section. The filter screen opening and closing mechanism includes a connecting rod. One end of the connecting rod is hinged to the rear end of a lever, and the other end is hinged to the side of a rigid filter screen facing the water flow direction. The side of the rigid filter screen facing away from the water flow direction is hinged to the edge of the opening of the detection box. The side of the rigid filter screen facing the water flow direction is connected to the corresponding edge of the opening of the detection box through a flexible filter screen.

2. The fluid pressure detection device for adjusting resistance by varying diameter according to claim 1, characterized in that, The venturi tube is tilted so that when the rigid filter is rotated to its limit position around its hinge point, the axis of the suction tube is perpendicular to the outer surface of the rigid filter.

3. The fluid pressure detection device for adjusting resistance by varying diameter according to claim 1, characterized in that, The connecting rod is an elastic connecting rod, and its length can be adjusted along the axial direction.

4. The fluid pressure detection device for adjusting resistance by varying diameter according to claim 1, characterized in that, The suction tube has a flared opening at its inlet.

5. A fluid pressure detection device for adjusting resistance by varying diameter according to claim 1, characterized in that, The inlet of the inlet section has a flared opening, and the elastic sealing ball contacts and engages with the flared opening to achieve a sealed closure of the inlet section.

6. The fluid pressure detection device for adjusting resistance by varying diameter according to claim 1, characterized in that, A strain gauge pressure sensor consists of a pressure-sensitive diaphragm and a strain resistor.

7. The fluid pressure detection device for adjusting resistance by varying diameter according to claim 1, characterized in that, The piston's outer circumference is inlaid with an elastic sealing ring to allow for sliding and sealing contact with the inner wall of the piston cylinder.

8. A fluid pressure detection device for adjusting resistance by varying diameter according to claim 1, characterized in that, It includes a mounting bracket fixed relative to the detection box, a venturi tube fixed to the mounting bracket, and a lever hinged to the mounting bracket via a hinge fulcrum.

9. A fluid pressure detection device for adjusting resistance by varying diameter according to claim 1, characterized in that, The elastic sealing ball is a hollow ball, and the front end of the lever has a circular plate, on which the elastic sealing ball is connected.

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