A self-locking seal detection device based on fluid pressure feedback

Abstract

This application relates to the field of fluid pressure measurement, and more specifically to the design of a pressure testing technology, particularly a self-locking seal detection device based on fluid pressure feedback. The device includes an auxiliary cylinder with an insertion hole on its outer surface, a sealing airbag on its outer surface, a piston plate inside the auxiliary cylinder, a fixing plate and a return spring inside the auxiliary cylinder, a transmission assembly on its outer surface, an abutment plate on its outer surface, a driving mechanism on its outer surface, a wedge block on its outer surface, an insertion post on its outer surface, and a sliding ring on its outer surface. In this application, when the fluid pressure pushes the piston plate, the insertion block inserts into the insertion hole to achieve initial locking. Simultaneously, the connecting rod structure pushes the abutment plate outward, enhancing the self-locking effect and preventing seal failure during testing.

Description

Technical Field

[0001] This application relates to the field of fluid pressure measurement, and more specifically to the design of pressure testing technology, particularly to a self-locking seal detection device based on fluid pressure feedback. Background Technology

[0002] In the field of modern industrial manufacturing, the sealing test of pressure vessels, high-pressure pipelines and precision hydraulic components is a fundamental link to ensure the safe operation of the system. As the automotive testing equipment industry evolves towards ultra-high pressure and high cleanliness, traditional sealing testing methods are facing unprecedented technical challenges. In these high-precision fields, the internal pressure of the workpiece under test often reaches tens or even hundreds of megapascals, which puts forward almost stringent requirements on the connection reliability of the testing device.

[0003] Traditional sealing test connectors mostly use manual mechanical locking, such as manual eccentric wheel or thread locking. However, these devices have significant limitations in practical applications. First, when the test pressure increases, the axial thrust generated by the fluid will directly act on the connector, attempting to separate it from the workpiece to be tested. If the external locking force is insufficient, the connector is very prone to "disengagement", which will not only damage the expensive workpiece to be tested, but may also cause serious production safety accidents such as explosion. Summary of the Invention

[0004] To address the issues of easy joint detachment and unstable sealing, this application provides a self-locking seal detection device based on fluid pressure feedback.

[0005] The self-locking seal detection device based on fluid pressure feedback provided in this application adopts the following technical solution:

[0006] A self-locking seal detection device based on fluid pressure feedback includes an auxiliary cylinder. The outer surface of the auxiliary cylinder has several insertion holes. The outer surface of the auxiliary cylinder is provided with a sealing airbag to ensure a seal between the auxiliary cylinder and the object to be tested. The inside of the auxiliary cylinder is provided with a piston plate to withstand fluid pressure. The inside of the auxiliary cylinder is provided with a fixing plate. A return spring is provided between the piston plate and the fixing plate. The outer surface of the auxiliary cylinder is provided with a transmission assembly for transmitting the axial movement force of the piston plate.

[0007] The outer surface of the auxiliary cylinder is provided with several abutment plates for the test object to expand and abut against it. The outer surface of the auxiliary cylinder is provided with a driving mechanism for driving the abutment plates to move. The outer surface of the auxiliary cylinder is provided with a wedge block. The outer surface of the auxiliary cylinder is provided with a plug-in post for secondary self-locking. The wedge block and the plug-in post are slidably adapted. The outer surface of the auxiliary cylinder is slidably provided with a moving ring.

[0008] By adopting the above technical solution, the outer surface of the auxiliary cylinder is provided with several insertion holes for engaging with the insertion blocks on the moving ring, thereby achieving relative fixation between the moving ring and the auxiliary cylinder. The outer surface of the auxiliary cylinder is provided with a sealing airbag to ensure a seal between the auxiliary cylinder and the object to be tested. The airbag expands and tightly adheres to the object to be tested to achieve a seal. Inside the auxiliary cylinder is a piston plate designed to withstand fluid pressure and move under the pressure. Inside the auxiliary cylinder is a fixed plate to provide support and sliding guidance for the connecting rod. A return spring is provided between the piston plate and the fixed plate to allow the piston plate to return to its original position after changes in fluid pressure. The outer surface of the auxiliary cylinder is provided with a transmission assembly for transmitting the axial movement force of the piston plate. The movement of the stopper plate is converted into the action of other components. The outer surface of the auxiliary cylinder is provided with several abutment plates for the test object to expand and abut against it. These plates are used to contact the outer surface of the test object and apply abutment force to prevent the device from falling out of the test object. The outer surface of the auxiliary cylinder is provided with a drive mechanism for moving the abutment plates. The abutment plates are moved to achieve the expansion and abutment action. The outer surface of the auxiliary cylinder is provided with wedge-shaped blocks, which cooperate with the insertion post to achieve a self-locking function. The outer surface of the auxiliary cylinder is provided with insertion posts for secondary self-locking. The wedge-shaped blocks and insertion posts are slidably adapted to each other. Self-locking is achieved through the relative sliding of the two. The outer surface of the auxiliary cylinder is slidably provided with a moving ring, which serves as a connection and moving carrier for the drive mechanism and other components.

[0009] Preferably, the transmission assembly includes a connecting rod, one end of which is fixedly disposed to the top of the piston plate, and the other end of which is disposed through the interior of the fixed plate and fixedly disposed on a push plate.

[0010] By adopting the above technical solution, one end of the connecting rod is fixedly set to the top of the piston plate, transmitting the axial movement of the piston plate to the other end. The other end of the connecting rod is inserted through the interior of the fixed plate and fixed to the push plate, driving the push plate to move, thereby driving the abutment plate to expand outward and the insertion post to move outward.

[0011] Preferably, the driving mechanism includes a fixed cylinder two disposed on the outer surface of the auxiliary cylinder, a movable frame two slidably disposed inside the fixed cylinder two on the top surface of the movable ring, a fixed cylinder one fixed on the outer surface of the auxiliary cylinder, a movable frame one slidably disposed inside the second annular cavity fixed on the bottom of the movable ring, and a plug-in block adapted to engage with the plug hole fixedly connected inside the movable ring.

[0012] By adopting the above technical solution, the fixed cylinder 2 is set on the top outer surface of the auxiliary cylinder, providing sliding space for the movable frame 2. A first annular cavity is formed between the inner wall of the fixed cylinder 2 and the outer wall of the auxiliary cylinder, serving as the sliding track for the movable frame 2. The top surface of the movable ring is provided with the movable frame 2, which is slidably disposed inside the first annular cavity, allowing the movable ring to slide relative to the top of the auxiliary cylinder. The outer surface of the auxiliary cylinder is fixed with the fixed cylinder 1, providing sliding space for the movable frame 1. A second annular cavity is formed between the inner wall of the fixed cylinder 1 and the outer wall of the auxiliary cylinder, serving as the sliding track for the movable frame 1. The bottom of the movable ring is fixed with the movable frame 1, which is slidably disposed inside the second annular cavity, allowing the movable ring to slide relative to the bottom of the auxiliary cylinder. The inside of the movable ring is fixedly connected with a plug-in block that is compatible with the plug hole, used to fix the relative position of the movable ring and the auxiliary cylinder.

[0013] Preferably, the driving mechanism further includes a connecting pipe fixed to the bottom surface of a fixed cylinder, and the other end of the connecting pipe is fixedly connected to and communicates with the sealing airbag.

[0014] By adopting the above technical solution, the connecting pipe is fixedly connected and communicates with the second annular cavity, connecting the second annular cavity with the sealing airbag. The other end of the connecting pipe is fixedly connected and communicates with the sealing airbag, allowing the fluid in the second annular cavity to enter the sealing airbag, thereby achieving the expansion and pressure balance of the sealing airbag.

[0015] Preferably, the outer surface of the fixed cylinder is provided with a plurality of fixed plates, and the sides of the fixed plates are symmetrically and rotatably provided with connecting rods. The side of the connecting rods away from the fixed plates is rotatably connected to the abutment plate, and the outer surface of the moving ring is rotatably connected with connecting rods that are rotatably provided to the abutment plate.

[0016] By adopting the above technical solution, the second fixed plate provides an installation and fixing point for the first connecting rod. The first connecting rod is symmetrically and rotatably arranged on the side of the second fixed plate, connecting the fixed position of the second fixed plate to the abutment plate. The side of the first connecting rod away from the second fixed plate is rotatably connected to the abutment plate, so that the abutment plate can rotate relative to the first connecting rod. The outer surface of the moving ring is rotatably connected to the second connecting rod, which is rotatably arranged with the abutment plate. The movement of the moving ring drives the second connecting rod, which in turn drives the abutment plate to move to achieve outward expansion and abutment.

[0017] Preferably, the wedge block is fixedly disposed on the outer surface of the moving ring, an n-shaped auxiliary plate is disposed on the outer surface of the fixed cylinder, the plug is slidably disposed inside the n-shaped auxiliary plate, a baffle is fixedly disposed on one side of the plug, and a second reset spring for driving the plug to reset is fixed between the baffle and the n-shaped auxiliary plate.

[0018] By adopting the above technical solution, the wedge block is fixedly set on the outer surface of the moving ring and moves with the moving ring. An n-shaped auxiliary plate is set on the outer surface of the fixed cylinder to provide sliding support and guidance for the plug-in post. The plug-in post is slidably set inside the n-shaped auxiliary plate and can slide inside the n-shaped auxiliary plate to achieve self-locking and unlocking. A baffle is fixed on one side of the plug-in post to limit the sliding range of the plug-in post. A reset spring 2 for driving the plug-in post to reset is fixed between the baffle and the n-shaped auxiliary plate so that the plug-in post can reset after losing external force.

[0019] Preferably, the auxiliary cylinder is hollow inside to form a fluid channel and has an axial guide groove.

[0020] By adopting the above technical solution, the internal cavity of the auxiliary cylinder is hollow, forming a fluid channel that allows the fluid to flow within the device. It is also machined with a precision axial guide groove to provide a sliding track for the guide key of the piston plate, ensuring that the piston plate can only move axially.

[0021] Preferably, the inclined angle of the wedge block is 30°-60°. When the moving ring moves, the wedge block can push the plug pin to move outward against the elastic force of the second reset spring, thereby achieving a self-locking function.

[0022] By adopting the above technical solution, the inclined plane angle of the wedge block is 30°-60°. This angle design allows the wedge block to push the plug pin to move outward against the elastic force of the second reset spring when the moving ring moves, thus achieving a self-locking function. Within this angle range, the pushing force and self-locking effect can be well balanced.

[0023] Preferably, the sealing airbag is made of highly elastic rubber material, and its internal pressure is dynamically balanced with the fluid pressure inside the auxiliary cylinder through the connecting pipe and the second annular cavity. The expansion of the sealing airbag is automatically adjusted according to the fluid pressure.

[0024] By adopting the above technical solution, the sealing airbag is made of highly elastic rubber material, which has good elasticity and sealing performance. Its internal pressure and the fluid pressure inside the auxiliary cylinder are dynamically balanced through the connecting pipe and the second annular cavity, so that the sealing airbag can adjust the internal pressure according to the fluid pressure change. The expansion of the sealing airbag is automatically adjusted according to the fluid pressure, thereby better fitting with the object to be tested to achieve sealing.

[0025] Preferably, a pressure sensor is installed in the fluid channel inside the auxiliary cylinder to monitor the fluid pressure in real time and transmit the pressure signal to an external control system, which then controls the operating status of the device based on the pressure signal.

[0026] By adopting the above technical solution, a pressure sensor is installed in the fluid channel inside the auxiliary cylinder to monitor the fluid pressure in real time, convert the pressure signal into an electrical signal, and transmit the pressure signal to the external control system, so that the external system can obtain the fluid pressure information. The external control system controls the working status of the device according to the pressure signal, such as controlling the fluid inflow and outflow and driving the mechanism to move.

[0027] In summary, this application includes at least one of the following beneficial technical effects:

[0028] 1. The auxiliary cylinder has a precision-machined axial guide groove, and the piston plate has a matching guide key on its outer wall. This design ensures that the piston plate can only slide axially and cannot rotate. Under fluid pressure, the movement of the piston plate is more precise and stable, avoiding friction and energy loss caused by rotation, improving the accuracy of the device's response to fluid pressure feedback, and making the sealing detection process more reliable.

[0029] 2. By utilizing the cooperation of the moving ring, the insertion block, and the insertion hole on the outer surface of the auxiliary cylinder, as well as the linkage structure composed of connecting rod one, connecting rod two, and the abutment plate, when the fluid pressure reaches a certain value and pushes the piston plate to move, it will drive the moving ring to move, so that the insertion block can be inserted into the insertion hole to achieve initial locking. At the same time, the connecting rod structure further pushes the abutment plate to expand outward, enhancing the self-locking effect and realizing the self-balancing characteristic of "the higher the pressure, the more stable the locking". This multi-stage self-locking mechanism can effectively prevent the seal from failing due to pressure fluctuations or other factors during the testing process, greatly improving the stability and safety of the seal testing.

[0030] 3. The fixed cylinder is connected to the sealing airbag via a connecting pipe. The movement of the moving ring not only achieves self-locking but also adjusts the expansion degree of the sealing airbag by changing the pressure inside the fixed cylinder. This design allows the device to flexibly adjust the sealing force according to different internal pressures and sealing requirements of the equipment, adapting to sealing detection needs under various working conditions and improving the device's versatility and practicality.

[0031] 4. The structure consisting of an n-shaped auxiliary plate, a plug-in post, a baffle, and a second return spring provides an additional self-locking device for the apparatus. When the moving ring moves to its final stage, the wedge block on the moving ring contacts and pushes the plug-in post. The plug-in post slides within the n-shaped auxiliary plate, compressing the second return spring. This mechanism may serve two purposes: first, when the maximum design pressure is reached, it provides an additional locking state or triggers a limit signal through the lateral movement of the plug-in post; second, when the pressure increases abnormally, it acts as a mechanical buffer and overload protection trigger point to prevent damage to the main locking mechanism (such as the plug-in block) due to overload. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the overall structure of this application;

[0033] Figure 2 This is a schematic diagram of the detection device structure in this application;

[0034] Figure 3 This is a schematic diagram of the internal structure of the auxiliary cylinder in this application;

[0035] Figure 4 This is a schematic diagram of the connection structure of the connecting pipes in this application;

[0036] Figure 5 This is a schematic diagram of the internal structure of the fixed cylinder II in this application;

[0037] Figure 6 This is a partial exploded view of the structure of this application;

[0038] Figure 7 For the purposes of this application Figure 6 Enlarged schematic diagram of the structure at point A in the middle;

[0039] Figure 8 This is a schematic diagram of the moving state structure of the abutment plate in this application;

[0040] Figure 9 This is a schematic diagram of the connection structure of the plug-in pins in this application.

[0041] Reference numerals: 1. Auxiliary cylinder; 11. Piston plate; 12. Connecting rod; 13. Fixing plate one; 14. Return spring one; 15. Push plate; 16. Insertion hole;

[0042] 2. Fixed cylinder one; 21. Moving frame one; 22. Moving ring; 23. Fixed cylinder two; 24. Moving frame two; 25. Fixed plate two; 26. Connecting rod one; 27. Abutment plate; 28. Connecting rod two;

[0043] 29. Insert block; 210. Connecting pipe; 211. Sealing airbag; 212. Wedge block; 213. N-type auxiliary plate; 214. Insert post; 215. Baffle; 216. Second return spring. Detailed Implementation

[0044] The following is in conjunction with the appendix Figures 1-9 This application will be described in further detail.

[0045] This application discloses a self-locking seal detection device based on fluid pressure feedback.

[0046] Reference Figures 1-3A self-locking seal detection device based on fluid pressure feedback includes an auxiliary cylinder 1. The interior of the auxiliary cylinder 1 is hollow to form a fluid channel and is machined with a precision axial guide groove. Several insertion holes 16 are formed on the outer surface of the auxiliary cylinder 1, arranged in a vertical array. Insertion blocks 29 sequentially engage with insertion holes 16 at different heights during the downward movement of the moving ring 22, forming a graded positioning. The opening edges of the insertion holes 16 are designed with chamfers or bevels for disengagement. A sealing airbag 211 is fixedly connected to the bottom outer surface of the auxiliary cylinder 1. The sealing airbag 211 ensures a seal between the auxiliary cylinder 1 and the object to be tested. The sealing airbag 211 is made of polyurethane (PU) or nitrile rubber (NBR). NBR), and its axial ends are covered with polytetrafluoroethylene (PTFE) anti-extrusion rings. A piston plate 11 is slidably connected inside the auxiliary cylinder 1. The piston plate 11 is used to bear fluid pressure, and a protruding guide key is fixed on the outer wall of the piston plate 11, which cooperates with the axial guide groove of the auxiliary cylinder 1, so that the piston plate 11 can only slide along the axial direction and cannot rotate. A fixing plate 13 is fixedly connected to the top of the inner wall of the auxiliary cylinder 1. A return spring 14 is fixedly connected to the top surface of the piston plate 11. The side of the return spring 14 away from the piston plate 11 is fixedly connected to the bottom surface of the fixing plate 13. A transmission assembly for transmitting the axial movement force of the piston plate 11 is provided on the outer surface of the auxiliary cylinder 1.

[0047] The transmission assembly includes a connecting rod 12, one end of which is fixedly connected to the top of the piston plate 11, and the other end of which is slidably connected through the center of the inner wall of the fixed plate 13. A push plate 15 is fixedly connected to the side of the connecting rod 12 away from the piston plate 11.

[0048] When the device is placed into the object to be tested, before the pressurized fluid is introduced, the piston plate 11 is located at the lower part of its stroke under the elastic force of the return spring 14. At this time, the connecting rod 12 and the push plate 15 are also in a lower position, and the sealing airbag 211 is in a contracted state and has not yet contacted the inner wall of the object to be tested.

[0049] When the sealing test begins, a pressurized fluid, such as compressed air or hydraulic oil, enters the hollow fluid channel of the auxiliary cylinder 1 from the bottom. The fluid pressure acts directly on the bottom end face of the piston plate 11, and the fluid pressure on the bottom of the piston plate 11 gradually increases. When the pressure overcomes the elastic force of the return spring 14, the piston plate 11 begins to slide upward along the axial guide groove on the inner wall of the auxiliary cylinder 1. Due to the precise fit between the guide key and the guide groove, the piston plate 11 is strictly restricted during the sliding process and can only make vertical upward linear movements without any rotation, ensuring the accuracy and stability of the transmission. As the piston plate 11 moves upward, the connecting rod 12, which is fixedly connected to it, is also driven to move upward together. The connecting rod 12 slides smoothly through the central hole of the fixed plate 13, accurately transmitting the movement of the piston plate 11 to the outside of the auxiliary cylinder 1. The push plate 15 at the top of the connecting rod 12 is pushed upward as the connecting rod 12 moves upward. At this time, the push plate 15 becomes a power output end, which converts the fluid pressure on the piston plate 11 into an upward mechanical thrust.

[0050] As the piston plate 11 moves upward, the reset spring 14 is further compressed. When the test ends and the fluid pressure is released, the compressed reset spring 14 will release its elasticity, pushing the piston plate 11, connecting rod 12 and push plate 15 downward to reset the entire transmission assembly and prepare for the next test.

[0051] Reference Figures 4-8 The outer surface of the auxiliary cylinder 1 is provided with several abutment plates 27, which are used for the external abutment of the object to be tested. The outer surface of the auxiliary cylinder 1 is provided with a driving mechanism, which is used to drive the abutment plates 27 to move. The outer surface of the auxiliary cylinder 1 is provided with a wedge block 212, the slope angle of the wedge block 212 is 30°-60° (45° can be selected). When the moving ring 22 moves, the wedge block 212 can push the insertion post 214 to move outward against the elastic force of the reset spring 216, so as to realize the self-locking function. The outer surface of the auxiliary cylinder 1 is provided with an insertion post 214, which is used for secondary self-locking. The wedge block 212 and the insertion post 214 are slidably adapted. The outer surface of the auxiliary cylinder 1 is slidably connected with the moving ring 22.

[0052] The driving mechanism includes a fixed cylinder 23, which forms a U-shaped oil passage with the push plate 15. Air or fluid is present within the U-shaped oil passage to drive the moving ring 22. The fixed cylinder 23 is fixedly connected to the top outer surface of the auxiliary cylinder 1. A first annular cavity is formed between the inner wall of the fixed cylinder 23 and the outer wall of the auxiliary cylinder 1. A moving frame 24 is fixedly connected to the top surface of the moving ring 22 and slidably connected inside the first annular cavity. A fixed frame is fixedly connected to the bottom outer surface of the auxiliary cylinder 1. The inner wall of the fixed cylinder 2 and the outer wall of the auxiliary cylinder 1 form a second annular cavity. The bottom of the moving ring 22 is fixedly connected to the moving frame 21, which is slidably connected inside the second annular cavity. The inner wall of the moving ring 22 is fixedly connected to the insertion block 29, which is engaged with the insertion hole 16. The engagement of the insertion block 29 with the multiple insertion holes 16 is not to "lock" the moving ring 22, but to prevent it from accidentally retracting during pressure fluctuations or vibrations. This is coarse positioning.

[0053] Since each socket 16 and the mating surface of the plug block 29 are provided with a chamfer or bevel for disengagement, the plug block 29 can slide out of the current socket 16 and into the next socket 16 under the continuous downward pushing force, thereby realizing the gradual downward movement of the moving ring 22 and the progressive expansion of the abutment plate 27 until the moving ring 22 reaches the final position.

[0054] The drive mechanism also includes several connecting pipes 210, which are fixedly connected to the bottom surface of the fixed cylinder 2 in a circumferential array, and the connecting pipes 210 are connected to the second annular cavity. The other end of the connecting pipes 210 is fixedly connected to and communicates with the sealing airbag 211.

[0055] The outer surface of the fixed cylinder 2 has a circumferential array of several fixed plates 25. The two sides of the fixed plates 25 are symmetrically connected to connecting rods 26. The side of the connecting rods 26 away from the fixed plates 25 is rotatably connected to the plane of the abutment plate 27. The outer surface of the moving ring 22 is rotatably connected to connecting rods 28. The side of the connecting rods 28 away from the moving ring 22 is rotatably connected to the upper part of the abutment plate 27.

[0056] Pre-positioning stage: The staff puts the device into the object to be tested, and then manually pushes the moving ring 22 down, which in turn drives the connecting rod 28 to deflect, which in turn drives the abutment plate 27 to swing outward and expand with the connection point of the connecting rod 26 as the fulcrum. This only achieves the initial support of the device in the object to be tested. At this time, the abutment plate 27 is not completely pressed against the inner wall, and there is an obvious radial gap.

[0057] Adaptive locking stage: As mentioned above, when a pressurized fluid such as compressed air or hydraulic oil enters the hollow fluid channel of the auxiliary cylinder 1 from the bottom, the fluid pressure directly acts on the bottom end face of the piston plate 11, thereby pushing the push plate 15 upward. Since there is air or fluid between the fixed cylinder 23 and the push plate 15, when the push plate 15 moves upward, it will push the air or fluid to squeeze the moving ring 22, causing the moving ring 22 to slide downward along the outer wall of the auxiliary cylinder 1. As the moving ring 22 moves downward, the insertion block 29 fixedly connected to the annular inner wall of the moving ring 22 moves downward synchronously and is sequentially inserted into the insertion holes 16 at different heights. Each time it is inserted into an insertion hole 16, the moving ring 22 obtains temporary fixation at that position to prevent accidental retraction. However, since the mating surface between the insertion hole 16 and the insertion block 29 has a chamfer or bevel for disengagement, under the continuous downward pushing force, the insertion block 29... It can detach from the current socket 16 and enter the next socket 16, realizing the gradual downward movement of the moving ring 22. When the moving ring 22 moves downward, the plug block 29 will be locked in the socket 16 to fix the position of the moving ring 22. At the same time as the moving ring 22 moves downward, the moving frame 21 fixedly connected to its bottom slides in the second annular cavity of the fixed cylinder 2. The sliding of the moving frame 21 will squeeze the fluid such as hydraulic oil or gas pre-filled in the second annular cavity. The squeezed fluid is pressed into the sealing airbag 211 through the connecting pipe 210 of the circumferential array on the bottom surface of the fixed cylinder 2. As the fluid continues to flow in, the sealing airbag 211 gradually expands, tightly adheres to and presses against the inner wall of the device under test, realizing a reliable seal between the device and the device under test. The higher the fluid pressure, the greater the squeezing force of the moving frame 21, the more fully the sealing airbag 211 expands, and the stronger the sealing effect.

[0058] During the downward movement of the moving ring 22, the connecting rod 28, which is rotatably connected to its outer surface, is driven to move downward. The other end of the connecting rod 28 is rotatably connected to the upper part of the abutment plate 27. The lower part of the abutment plate 27 is rotatably connected to the fixing plate 25 on the outer surface of the fixing cylinder 2 through the symmetrically arranged connecting rod 26, forming a stable linkage mechanism. When the connecting rod 28 pushes the abutment plate 27 downward, the abutment plate 27 swings outward and expands with its connection point with the connecting rod 26 as the fulcrum. Multiple circumferential arrays of abutment plates 27 swing outward synchronously, firmly pressing against the inner wall of the device under test, fixing the entire device in the center of the device under test, and preventing the device from being blown out during subsequent high-pressure testing.

[0059] As can be seen from the above description, when pressurized fluid is introduced, the piston plate 11 moves upward, and the push plate 15 pushes the moving ring 22 to slide downward;

[0060] Synchronous action: Every time the moving ring 22 slides down a certain distance, the following occurs simultaneously: the plug block 29 engages with the current plug hole 16 (graded positioning, not final locking), the connecting rod 28 drives the abutment plate 27 to swing outward further, and the moving frame 21 compresses the fluid to further expand the sealing airbag 211.

[0061] Therefore, the outward expansion angle of the abutment plate 27 is proportional to the downward movement distance of the moving ring 22, and the downward movement distance of the moving ring 22 is determined by the fluid pressure (the upward movement of the piston plate 11). The higher the pressure, the more the moving ring 22 moves downward and the greater the outward expansion of the abutment plate 27. The two are synchronous and continuous mapping relationships, and there is no disconnected stage of "first fully pressing and then the pressure increases".

[0062] When the contact plate 27 contacts the inner wall of the object to be tested, if the fluid pressure continues to rise, the moving ring 22 moves further down, and the force applied by the connecting rod 28 to the contact plate 27 changes from position drive to increased clamping force. The geometric characteristics of the linkage mechanism allow the moving ring 22 to move down a certain distance even if the radial displacement is restricted by the inner wall, thereby reducing the angle between the connecting rod 28 and the connecting rod 26, thus increasing the positive pressure of the contact plate 27 on the inner wall and enhancing the pressure feedback of the anti-explosion capability. At the same time, the inner wall of the object to be tested will undergo slight elastic deformation under the continuous radial force, providing further radial space for the contact plate 27.

[0063] The expansion of the abutment plate 27 includes the increase in the radial displacement of the abutment plate 27 and the increase in the positive pressure between the abutment plate 27 and the inner wall of the object to be tested. Both are considered to realize the "expansion and tightening" function of the abutment plate 27.

[0064] Reference Figure 2 , Figure 9 The wedge block 212 is fixedly connected to the outer surface of the moving ring 22, and the wedge block 212 is located between two adjacent connecting rods 28. An n-shaped auxiliary plate 213 is fixedly connected to the outer surface of the fixed cylinder 2. The n-shaped auxiliary plate 213 is located directly below the wedge block 212. The plug-in post 214 is slidably connected through the inside of the n-shaped auxiliary plate 213. A baffle 215 is fixedly connected to one-third of the side of the plug-in post 214 near the fixed cylinder 2. A return spring 216 is fixedly connected to the side of the baffle 215 near the n-shaped auxiliary plate 213. The side of the return spring 216 away from the baffle 215 is fixedly connected to the n-shaped auxiliary plate 213. The return spring 216 is used to drive the plug-in post 214 to return to its original position.

[0065] In the final stage of the downward movement of the moving ring 22, the wedge block 212 fixed on its outer surface also moves downward. The inclined surface of the wedge block 212, preferably at 45°, first contacts the end of the insertion post 214. As the moving ring 22 continues to move downward, the inclined surface of the wedge block 212 converts the vertical movement of the moving ring 22 into a lateral thrust on the insertion post 214, pushing the insertion post 214 to overcome the elastic force of the return spring 216 and move it away from the auxiliary cylinder 1 within the n-shaped auxiliary plate 213. As the sliding ring 22 moves down to its final position, i.e., the plug block 29 is inserted into the corresponding socket 16, the sealing airbag 211 is fully inflated and the abutment plate 27 is fully pressed against it. At this time, the vertical surface of the wedge block 212 just passes the end of the plug post 214. At this time, the elastic force of the return spring 216 pushes the plug post 214 to return to its original position, so that its end is tightly pressed against the vertical surface of the wedge block 212. This one-way locking action realizes the mechanical self-locking of the position of the moving ring 22.

[0066] When the test is completed and the internal fluid pressure is released, the piston plate 11 moves down under the action of the return spring 14, and the push plate 15 descends accordingly. At this time, because the insertion post 214 is locked to the vertical surface of the wedge block 212, the moving ring 22 cannot move down automatically. An external force is required to release the self-locking, such as manually pulling the insertion post 214 or pushing it through other mechanisms, so that the insertion post 214 overcomes the elastic force of the return spring 216 and exits outward, releasing the lock on the wedge block 212. The entire device returns to its initial state and can be removed from the device under test.

[0067] Among them, the sealing airbag 211 is made of high elastic rubber material. Its internal pressure and the fluid pressure inside the auxiliary cylinder 1 are dynamically balanced through the connecting pipe 210 and the second annular cavity. The expansion amount of the sealing airbag 211 is automatically adjusted according to the fluid pressure.

[0068] A pressure sensor is installed in the fluid channel inside the auxiliary cylinder 1 to monitor the fluid pressure in real time and transmit the pressure signal to the external control system. The external control system controls the working status of the device according to the pressure signal.

[0069] The return spring 14 and return spring 216 both adopt the calculation formula of alloy spring: F=kx, where F is the external force on the spring, k is the spring constant, and x is the deformation of the spring, in meters. The elastic force of the alloy spring is then calculated so that it can be used in this device.

[0070] The auxiliary cylinder 1 is made of 17-4PH stainless steel forging in H1150 condition, which has excellent resistance to hydrogen embrittlement. The seal between the piston plate 11 and the auxiliary cylinder 1 is made of polytetrafluoroethylene (PTFE) plug seal.

[0071] The effective cross-sectional area of ​​the second annular cavity is set to 0.8 times the effective area of ​​the piston, so that the pressure inside the airbag is slightly higher than the test pressure, forming a positive pressure difference and ensuring zero leakage.

[0072] The connecting pipe 210 is equipped with a one-way damping valve, so that even if the airbag bursts instantly, the hydraulic oil in the cavity will not spray out instantly, thereby maintaining the mechanical locking force through the inertia of the moving ring 22 and preventing the device from ejecting due to sudden pressure loss.

[0073] In this device, the sealing function is undertaken by the sealing airbag 211. After the airbag expands, it forms a gapless fit with the inner wall, achieving a zero-leakage seal. The function of the abutment plate 27 is to prevent the device from being axially ejected under high pressure (providing mechanical obstruction); to ensure that the device is coaxial with the object to be tested, and to avoid airbag bias. Therefore, the abutment plate 27 does not need to expand infinitely. As long as the positive pressure of the abutment plate 27 on the inner wall increases accordingly when the pressure increases, the anti-ejection capability will be enhanced accordingly.

[0074] The implementation principle of a self-locking seal detection device based on fluid pressure feedback in this application embodiment is as follows:

[0075] After placing the device into the object to be tested, manually push the moving ring 22 to pre-expand the contact plate 27 for initial installation. Then, pressurized fluid is introduced, and the piston plate 11 slides upward against the force of the return spring 14 under the fluid pressure. This causes the push plate 15 to move upward via the connecting rod 12. The push plate 15 pushes the moving ring 22 downward along the outer wall of the auxiliary cylinder 1, causing the insertion block 29 to engage with the insertion hole 16 and fix the position of the moving ring 22. At the same time, the moving frame 21 compresses the fluid in the second annular cavity through the connecting... The tube 210 inflates the sealing airbag 211 to press against the inner wall of the object to be tested. The connecting rod 28 moves down with the moving ring 22, driving the abutment plate 27 to swing outward and press against the object to be tested. In the final stage of the downward movement of the moving ring 22, the inclined surface of the wedge block 212 pushes the insertion post 214 outward. After it reaches the position, the reset spring 216 pushes the insertion post 214 to reset and lock the vertical surface of the wedge block 212 to achieve mechanical self-locking. After the test is completed and the pressure is released, the insertion post 214 needs to be manually pulled to release the self-locking. Once all components are reset, the device can be taken out.

[0076] The above are merely optional embodiments of this application and are not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A self-locking seal detection device based on fluid pressure feedback, characterized in that: The device includes an auxiliary cylinder (1), the outer surface of which is provided with a plurality of insertion holes (16), the outer surface of which is provided with a sealing airbag (211) for ensuring a seal between the auxiliary cylinder (1) and the object to be tested, the inner surface of which is provided with a piston plate (11) for bearing fluid pressure, the inner surface of which is provided with a fixing plate (13), a return spring (14) between the piston plate (11) and the fixing plate (13), and the outer surface of which is provided with a transmission assembly for transmitting the axial movement force of the piston plate (11). The outer surface of the auxiliary cylinder (1) is provided with a plurality of abutment plates (27) for the test object to be abutted outward. The outer surface of the auxiliary cylinder (1) is provided with a driving mechanism for driving the abutment plates (27) to move. The outer surface of the auxiliary cylinder (1) is provided with a wedge block (212). The outer surface of the auxiliary cylinder (1) is provided with a plug post (214) for secondary self-locking. The wedge block (212) and the plug post (214) are slidably adapted. The outer surface of the auxiliary cylinder (1) is slidably provided with a moving ring (22).

2. The self-locking seal detection device based on fluid pressure feedback according to claim 1, characterized in that: The transmission assembly includes a connecting rod (12), one end of which is fixedly disposed to the top of the piston plate (11), and the other end of which is disposed through the interior of the fixed plate (13) and fixedly disposed with a push plate (15).

3. The self-locking seal detection device based on fluid pressure feedback according to claim 1, characterized in that: The driving mechanism includes a fixed cylinder two (23) disposed on the outer surface of the auxiliary cylinder (1), a movable frame two (24) disposed on the top surface of the movable ring (22) and slidably disposed inside the fixed cylinder two (23), a fixed cylinder one (2) fixed on the outer surface of the auxiliary cylinder (1), a movable frame one (21) disposed on the bottom of the movable ring (22) and slidably disposed inside the second annular cavity, and a plug-in block (29) that is fitted and matched with the plug hole (16) is fixedly connected inside the movable ring (22).

4. The self-locking seal detection device based on fluid pressure feedback according to claim 3, characterized in that: The drive mechanism also includes a connecting pipe (210) fixed to the bottom surface of the fixed cylinder (2), and the other end of the connecting pipe (210) is fixedly connected to and communicates with the sealing airbag (211).

5. The self-locking seal detection device based on fluid pressure feedback according to claim 3, characterized in that: The outer surface of the fixed cylinder (2) is provided with several fixed plates (25). The side of the fixed plate (25) is symmetrically and rotatably provided with a connecting rod (26). The side of the connecting rod (26) away from the fixed plate (25) is rotatably connected to the abutment plate (27). The outer surface of the moving ring (22) is rotatably connected with a connecting rod (28) rotatably provided with the abutment plate (27).

6. The self-locking seal detection device based on fluid pressure feedback according to claim 3, characterized in that: The wedge block (212) is fixedly disposed on the outer surface of the moving ring (22). An n-shaped auxiliary plate (213) is disposed on the outer surface of the fixed cylinder (2). The plug-in post (214) is slidably disposed inside the n-shaped auxiliary plate (213). A baffle (215) is fixedly disposed on one side of the plug-in post (214), and a reset spring (216) for driving the plug-in post (214) to reset is fixed between the baffle (215) and the n-shaped auxiliary plate (213).

7. The self-locking seal detection device based on fluid pressure feedback according to claim 1, characterized in that: The auxiliary cylinder (1) is hollow inside, forming a fluid channel, and has an axial guide groove.

8. The self-locking seal detection device based on fluid pressure feedback according to claim 1, characterized in that: The inclined angle of the wedge block (212) is 30°-60°. When the moving ring (22) moves, the wedge block (212) can push the plug post (214) to move outward against the elastic force of the second reset spring (216).

9. The self-locking seal detection device based on fluid pressure feedback according to claim 1, characterized in that: The sealing airbag (211) is made of high elastic rubber material. Its internal pressure and the fluid pressure inside the auxiliary cylinder (1) are dynamically balanced through the connecting pipe (210) and the second annular cavity. The expansion of the sealing airbag (211) is automatically adjusted according to the fluid pressure.

10. The self-locking seal detection device based on fluid pressure feedback according to claim 1, characterized in that: A pressure sensor is installed in the fluid channel inside the auxiliary cylinder (1) to monitor the fluid pressure in real time and transmit the pressure signal to the external control system. The external control system controls the working status of the device according to the pressure signal.

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