Pipeline plugging device with large radial expansion ratio

Abstract

This invention discloses a pipe sealing device with a large radial expansion ratio, relating to the field of pipe sealing technology. It includes a support cylinder, a sealing mechanism, and a locking element. The support cylinder has a non-communicating inlet and outlet channel. The support cylinder has a positioning part, a connecting part, and a locking part arranged sequentially along its axis. The connecting part is fitted with a sealing mechanism, and the locking part is fitted with a locking element. The sealing mechanism includes a sealing rubber tube and elastic reset structures symmetrically fitted at both ends of the sealing rubber tube. The sealing rubber tube has an expansion cavity. The inlet channel is connected to the outlet channel through the expansion cavity. The elastic reset structure can expand radially outward during the pressurization process of the expansion cavity, conforming to the inner wall of the pipe to form an expansion seal. The sealing rubber tube can elastically contract radially inward during the depressurization process of the expansion cavity, following the elastic reset structure. This device features a large radial expansion ratio and good pipe sealing effect.

Description

Technical Field

[0001] This invention relates to the field of pipeline plugging technology, and more particularly to a pipeline plugging device with a large radial expansion ratio. Background Technology

[0002] Currently, oil and gas pipelines, chemical pipelines, and natural water pipelines are susceptible to damage due to various factors such as corrosion, mechanical wear, earthquakes, and ruptures. Therefore, timely and effective maintenance and repair of pipelines are crucial to ensuring their reliability. Against this backdrop, the sealing mechanism of pipeline plugging robots has become an important research area to ensure the effective plugging of pipelines during maintenance and repair. This technology is essential for internal pipe plugging operations in emergency leak repair.

[0003] Pipeline plugging technology using extrusion-type sealing cartridges has therefore attracted much attention. However, when plugging high-pressure media in pipelines, this technology typically requires a small gap between the sealing cartridge and the pipeline to be plugged in order to prevent the sealing cartridge from bulging outwards and causing plugging failure. This reduces the mobility of the pipeline plugging robot when operating inside the pipeline. In addition, the process of extruding and expanding the sealing cartridge using this technology requires a large axial force, which places excessive demands on the hydraulic system, resulting in a large hydraulic system with a complex structure. Summary of the Invention

[0004] The purpose of this invention is to provide a pipe plugging device with a large radial expansion ratio, which at least solves the problem of poor maneuverability of pipe plugging robots when walking inside pipes in the prior art.

[0005] The above-mentioned objectives of the present invention can be achieved by the following technical solutions:

[0006] This invention provides a pipe plugging device with a large radial expansion ratio, comprising:

[0007] The support cylinder has a positioning part, a connecting part, and a locking part arranged sequentially along the axial direction. The support cylinder is provided with a liquid inlet channel and a liquid outlet channel that are not interconnected.

[0008] A sealing mechanism includes a sealing sleeve and an elastic reset structure. The sealing sleeve is sleeved outside the connecting portion. The sealing sleeve has an expansion cavity. The inlet channel is connected to the outlet channel through the expansion cavity. The sealing sleeve extends radially outward to form a pipe contact portion. Both ends of the sealing sleeve have connecting portions extending radially outward. An anti-protrusion portion is formed between the connecting portion and the pipe contact portion. The elastic reset structure is symmetrically arranged on both sides of the expansion cavity. The elastic reset structure is connected to the sealing sleeve through the connecting portion. An anti-protrusion groove corresponding to the anti-protrusion portion is formed on the elastic reset structure.

[0009] A locking element is sleeved on the locking part, and the locking element is used to axially limit the sealing mechanism;

[0010] The elastic reset structure can expand radially outward and fit against the inner wall of the pipe to form an expansion seal as the sealing tube is filled with expansion fluid into the expansion cavity through the liquid inlet channel.

[0011] The sealing sleeve can elastically contract and reset radially inward as the elastic reset structure discharges the swollen fluid from the swollen fluid accommodating cavity into the fluid outlet channel.

[0012] Wherein, along the axial direction of the support cylinder, the contour projection of the pipe contact portion coincides with the contour projection of the anti-protrusion groove.

[0013] In one specific embodiment, the elastic reset structure includes an elastic retaining ring, an opening is formed in the radial direction of the elastic retaining ring, and a plurality of openings are spaced apart along the circumferential direction on the elastic retaining ring.

[0014] In one specific embodiment, the opening directions of two adjacent openings are arranged in opposite directions along the circumferential direction of the elastic retaining ring.

[0015] In one specific embodiment, the elastic reset structure further includes at least one first reset spring embedded in the elastic retaining ring, and the elastic retaining ring is provided with a first slot for accommodating the first reset spring.

[0016] In one specific embodiment, the elastic reset structure further includes at least one second reset spring embedded in the elastic retaining ring. The second reset spring is correspondingly embedded in a second slot on the elastic retaining ring, and the first slot and the second slot are arranged radially outward along the elastic retaining ring.

[0017] In one specific embodiment, the elastic reset structure includes a plurality of first reset springs and a plurality of second reset springs spaced apart along the axial direction of the support cylinder, and the elastic retaining ring is provided with a plurality of first slots and a plurality of second slots for accommodating the plurality of first reset springs and the plurality of second reset springs.

[0018] In one specific embodiment, the liquid inlet channel is connected to the expansion cavity via a liquid inlet nozzle, and the liquid outlet channel is connected to the expansion cavity via a liquid outlet nozzle.

[0019] In one specific embodiment, the inner wall of the sealing tube extends radially inward to form a sealing protrusion ring, and at least one pair of sealing protrusion rings are symmetrically arranged on the sealing tube along its axial direction. The liquid inlet nozzle and the liquid outlet nozzle are arranged between at least one pair of the sealing protrusion rings.

[0020] During the expansion sealing process, the initial contact pressure between the sealing protrusion ring and the support cylinder is P0.

[0021] After the sealing tube is pressurized to P1, the initial contact pressure between the sealing surface of the sealing tube and the inner wall of the pipe is P2.

[0022] The internal pressure of the sealing rubber cylinder gradually increases to P4 under the action of the pipeline medium pressure P3;

[0023] The final contact pressure between the sealing protrusion ring and the support cylinder is: P0 + P4;

[0024] The final contact pressure between the sealing surface of the sealing tube and the inner wall of the pipe is: P2 + P3.

[0025] The features and advantages of this invention are:

[0026] 1. The pipe plugging device with a large radial expansion ratio provided by the present invention effectively prevents the sealing tube from protruding outward by means of elastic reset structures symmetrically arranged at both ends of the sealing tube, under the premise of a large gap between the sealing tube and the pipe to be plugged. This provides the pipe plugging robot with better pipe running passability while still being able to perform effective pipe plugging operations.

[0027] 2. The pipe plugging device with a large radial expansion ratio provided by the present invention has the characteristic of self-sealing due to expansion by setting a sealing protrusion ring, which can effectively prevent the pipe plugging failure caused by leakage of expansion fluid inside the sealing sleeve; at the same time, by setting a sealing sleeve to have the characteristic of expansion sealing, an excellent plugging effect is achieved. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a schematic diagram of the pipe sealing device with a large radial expansion ratio provided by the present invention in its initial / unsealed state.

[0030] Figure 2A perspective view of the sealing mechanism of the pipe plugging device with a large radial expansion ratio provided by the present invention;

[0031] Figure 3 A cross-sectional view of the sealing mechanism of the pipe plugging device with a large radial expansion ratio provided by the present invention;

[0032] Figure 4 for Figure 3 A magnified view of a portion of the image;

[0033] Figure 5 for Figure 3 Enlarged view of part B;

[0034] Figure 6 A perspective view of the sealing rubber cylinder of the pipe sealing device with a large radial expansion ratio provided by the present invention;

[0035] Figure 7 A cross-sectional view of the sealing rubber cylinder of the pipe plugging device with a large radial expansion ratio provided by the present invention;

[0036] Figure 8 for Figure 7 A magnified view of a portion of the image, C;

[0037] Figure 9 A perspective view of the elastic retaining ring of the pipe sealing device with a large radial expansion ratio provided by the present invention;

[0038] Figure 10 A plan view of the elastic retaining ring of the pipe plugging device with a large radial expansion ratio provided by the present invention;

[0039] Figure 11 for Figure 10 A magnified view of part D;

[0040] Figure 12 This is a schematic diagram of the opening arrangement of the elastic retaining ring of the pipe sealing device with a large radial expansion ratio provided by the present invention;

[0041] Figure 13 This is a schematic diagram of the pipe sealing device with a large radial expansion ratio provided by the present invention in the sealing state.

[0042] Explanation of icon numbers:

[0043] 1. Support cylinder; 11. Positioning part; 12. Connecting part; 121. Groove; 13. Locking part; 14. Liquid inlet channel; 15. Liquid outlet channel;

[0044] 2. Sealing mechanism; 21. Sealing sleeve; 211. Fluid expansion cavity; 212. Pipe contact part; 213. Connection part; 214. Anti-protrusion part; 215. Sealing protrusion ring; 216. Gap ring; 22. Elastic reset structure; 221. Elastic retaining ring; 2211. Anti-protrusion groove; 2212. Opening; 2213. First slot; 22131. Anti-detachment surface; 2214. Second slot; 222. First reset spring; 223. Second reset spring;

[0045] 3. Locking components;

[0046] 4. Liquid inlet nozzle;

[0047] 5. Liquid outlet nozzle;

[0048] 6. Pipelines;

[0049] R, inner cavity radius; R1, end radius; R2, profile radius; α, included angle. Detailed Implementation

[0050] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0051] like Figures 1 to 13As shown, the present invention provides a pipe sealing device with a large radial expansion ratio, comprising: a support cylinder 1 having a positioning part 11, a connecting part 12, and a locking part 13 arranged sequentially along the axial direction; the support cylinder 1 having an inlet channel 14 and an outlet channel 15 that are not interconnected; and a sealing mechanism 2 having a sealing rubber tube 21 and an elastic reset structure 22. The sealing rubber tube 21 is sleeved outside the connecting part 12, and the sealing rubber tube 21 has an expansion cavity 211 inside. The inlet channel 14 is connected to the outlet channel 15 through the expansion cavity 211. The sealing rubber tube 21 extends radially outward to form a pipe contact part 212, and the two ends of the sealing rubber tube 21 have connecting parts 213 formed radially outward. The connecting parts 213 and the pipe contact parts 212 are connected by... An anti-protrusion portion 214 is formed in the space between the two sides of the expansion cavity 211. The elastic reset structure 22 is symmetrically arranged on both sides of the expansion cavity 211. The elastic reset structure 22 is connected to the sealing tube 21 through the connecting portion 213. An anti-protrusion groove 2211 corresponding to the anti-protrusion portion 214 is formed on the elastic reset structure 22. The locking member 3 is sleeved on the locking portion 13 and is used to axially limit the sealing mechanism 2. The elastic reset structure 22 can expand radially outward and fit against the inner wall of the pipe 6 to form an expansion seal as the sealing tube 21 is filled with expansion liquid in the inlet channel 14. The sealing tube 21 can elastically contract and reset radially inward as the expansion cavity 211 discharges expansion liquid into the outlet channel 15.

[0052] Specifically, such as Figures 1 to 3 , Figure 13 As shown, a pipe sealing device with a large radial expansion ratio includes a support cylinder 1, a sealing mechanism 2, and a locking element 3. The support cylinder 1 has an inlet channel 14 and an outlet channel 15 that are not interconnected. The support cylinder 1 has a positioning part 11, a connecting part 12, and a locking part 13 arranged sequentially along the axial direction. The sealing mechanism 2 is connected to the outer sleeve of the connecting part 12, and the locking element 3 is connected to the outer sleeve of the locking part 13. That is, the sealing mechanism 2 is positioned between the positioning part 11 and the locking element 3 and is axially limited by the positioning part 11 and the locking element 3. The sealing mechanism 2 includes a sealing rubber sleeve 21 and an elastic reset structure 22. The sealing rubber sleeve 21 is made of nitrile rubber with excellent elasticity and resilience, and excellent resistance to oil and gas, extruded through a mold. The sealing mechanism 2 is sleeved on the outer sleeve of the connecting part 12 through the sealing rubber sleeve 21. The sealing rubber sleeve 21 has an expansion cavity 211, and the inlet channel 14 is connected to the outlet channel 15 through the expansion cavity 211. Figures 6 to 9As shown, the sealing tube 21 extends radially outward to form a pipe contact portion 212. Connecting portions 213 are formed radially outward at both ends of the sealing tube 21. Anti-protrusion portions 214 are formed between the connecting portions 213 and the pipe contact portions 212. The anti-protrusion portions 214 and the pipe contact portions 212 are arranged in a stepped manner in the radial direction. Elastic reset structures 22 are symmetrically arranged on the connecting portions 213 of the sealing tube 21 on both sides of the expansion cavity 211. Anti-protrusion grooves 2211 corresponding to the anti-protrusion portions 214 are formed on the elastic reset structure 22. Specifically, the elastic reset structure 22 has an overall annular main structure. A flange extending axially is formed on the outer contour surface of the elastic reset structure 22. The inner surface of the flange... The anti-protrusion groove 2211 is formed on the surface. The elastic reset structure 22 can expand radially outward and fit against the inner wall of the pipe 6 to form an expansion seal as the sealing rubber tube 21 follows the filling of the expansion cavity 211 with expansion liquid in the inlet channel 14. The sealing rubber tube 21 can elastically contract and reset radially inward as the expansion cavity 211 discharges expansion liquid into the outlet channel 15. That is, during the filling of the expansion cavity 211 with expansion liquid, the elastic reset structure 22 and the sealing rubber tube 21 expand radially outward synchronously until the outer contour surface fits against the inner wall of the pipe 6 to form an expansion seal. During the discharge of expansion liquid from the expansion cavity 211, the elastic reset structure 22 and the sealing rubber tube 21 contract radially inward synchronously to return to the initial position.

[0053] Specifically, along the axial direction of the support cylinder 1, the outline projection of the pipe contact portion 212 coincides with the outline projection of the anti-protrusion groove 2211. For example, Figure 1 , Figure 3 , Figure 4 and Figure 13As shown, after the elastic reset structure 22 cooperates with the sealing tube 21, the outline projection of the elastic reset structure 22 at the anti-protrusion groove 2211 and the pipe contact part 212 along the axial direction of the support tube 1 coincides. Specifically, the outer outline of the elastic reset structure 22 at the anti-protrusion groove 2211 and the outer outline of the pipe contact part 212 can be coplanar (i.e., located on the same cylindrical surface). Thus, when the elastic reset structure 22, which is symmetrically arranged on both sides of the expansion cavity 211, expands to seal the pipe 6 radially outward with the sealing tube 21, the outer wall surface of the anti-protrusion groove 2211 and the outer wall surface of the pipe contact part 212 simultaneously contact the inner wall of the pipe 6. At the same time, the pipe contact part 212 is tightly fitted to the inner wall of the pipe 6 with the minimum amount of pressure. At the same time, the anti-protrusion groove 2211 of the elastic reset structure 22 applies an axially opposite compressive constraint force to both ends of the pipe contact part 212 of the sealing tube 21, so as to effectively prevent the sealing tube 21 from causing the pipe 6 to fail due to the outward protrusion phenomenon. In this embodiment, when the contour projection of the pipe contact portion 212 is included by the contour projection of the elastic reset structure 22 at the anti-protrusion groove 2211, that is, when the outer wall contour diameter of the elastic reset structure 22 at the anti-protrusion groove 2211 is greater than the outer wall contour diameter of the pipe contact portion 212, the elastic reset structure 22 expands radially outward synchronously with the sealing sleeve 21 until its outer wall surface at the anti-protrusion groove 2211 contacts the inner wall of the pipe 6. At this time, the sealing sleeve 21 has not yet expanded to the point where the outer wall surface of the pipe contact portion 212 contacts the inner wall of the pipe 6. At this time, a cavity is formed between the pipe contact portion 212, the anti-protrusion groove 2211, and the pipe 6. The elastic reset structure 22, which is in contact with the liquid in the pipe 6, is easily deformed to one side of the cavity under the unidirectional pressure of the liquid, occupying the space for the radial outward expansion of the pipe contact portion 212. As a result, after continuous pressurization, the outer wall surface of the pipe contact portion 212 still cannot be completely and tightly fitted with the inner wall of the pipe 6. At the same time, a gap forms between the deformed elastic reset structure 22 and the inner wall of the pipe 6. When a gap is formed, the liquid inside the pipe 6 will continuously exert pressure on one side of the pipe contact part 212 through the gap, causing it to deform axially, which seriously affects the expansion and repositioning effect of the pipe sealing device. When the contour projection of the pipe contact part 212 includes the contour projection of the elastic repositioning structure 22 at the anti-protrusion groove 2211, that is, when the outer wall contour diameter of the elastic repositioning structure 22 at the anti-protrusion groove 2211 is smaller than the outer wall contour diameter of the pipe contact part 212, when the sealing sleeve 21 expands to the point where the outer wall of the pipe contact part 212 contacts the inner wall of the pipe 6, the outer wall of the elastic repositioning structure 22 at the anti-protrusion groove 2211, which expands radially outward with the sealing sleeve 21, has not yet contacted the inner wall of the pipe 6. Along the axial direction of the support cylinder 1, the part where the contour projection of the pipe contact part 212 is larger than the contour projection of the elastic repositioning structure 22 at the anti-protrusion groove 2211 is not constrained by the axial relative compression constraint force applied by the anti-protrusion groove 2211, and there is still a risk of outward protrusion, which may lead to sealing failure.

[0054] The inventors discovered that in the prior art, the gap between the sealing mechanism 2 and the pipe 6 to be sealed is usually about 3% of the inner diameter of the pipe 6 to be sealed. However, the gap between the pipe sealing device with a large radial expansion ratio provided by the present invention and the pipe 6 to be sealed can reach more than 15% of the inner diameter of the pipe 6 to be sealed, which is at least 5 times the gap in the prior art. The pipe sealing robot equipped with the pipe sealing device with a large radial expansion ratio provided by the present invention has better passing performance when passing through bends and deformed pipes 6.

[0055] In this embodiment, both the inlet channel 14 and the outlet channel 15 are equipped with switching valves to control the opening and closing of the channels. When the expansion fluid is injected into the expansion cavity 211 for expansion sealing, the switching valve on the inlet channel 14 is opened to allow the expansion fluid to flow into the expansion cavity 211. During the filling process, the switching valve on the outlet channel 15 remains open to allow the gas in the expansion cavity 211 to be discharged. To completely remove the gas from the expansion cavity 211 and ensure the reliability of the sealing sleeve 21 expansion sealing, before filling the expansion cavity 211 with expansion fluid, the position of the pipeline sealing device is adjusted to the upward direction of the outlet channel 15 to facilitate the effective discharge of gas in the expansion fluid. When the discharge from the outlet channel 15 changes from an oil-gas mixture to entirely oil, it indicates that all the gas in the expansion cavity 211 has been discharged, and the switching valve on the outlet channel 15 is closed. When the expansion fluid in the expansion fluid receiving cavity 211 is discharged outward to reset, the switch valve on the inlet channel 14 is closed, and the switch valve on the outlet channel 15 is opened. Hydraulic oil is preferably used as the expansion fluid filling the expansion fluid receiving cavity 211. Other fluids that do not react with the sealing sleeve 21 can also be used. Of course, expansion sealing can also be achieved by injecting air into the expansion fluid receiving cavity 211; this invention does not impose any limitations on this method.

[0056] The pipe plugging device with a large radial expansion ratio provided by the present invention effectively prevents the sealing tube 21 from protruding outward by means of the elastic reset structure 22 symmetrically arranged at both ends of the sealing tube 21, under the premise that there is a large gap between the sealing tube 21 and the pipe 6 to be plugged. This provides the pipe plugging robot with better pipe running passability while still being able to perform effective pipe 6 plugging operations.

[0057] According to one embodiment of the present invention, see reference. Figures 8 to 10 As shown, the elastic reset structure 22 includes an elastic retaining ring 221, an opening 2212 is formed in the radial direction of the elastic retaining ring 221, and a plurality of openings 2212 are spaced apart on the elastic retaining ring 221 along its circumferential direction.

[0058] Specifically, such as Figures 1 to 4 , Figures 9 to 13As shown, the elastic reset structure 22 is fitted onto the connecting portion 213 of the sealing tube 21 via an elastic retaining ring 221. The elastic retaining ring 221 has an anti-protrusion groove 2211 corresponding to the anti-protrusion portion 214 of the sealing tube 21. After the elastic retaining ring 221 and the sealing tube 21 are engaged, the outer wall profile diameter of the anti-protrusion groove 2211 is the same as the outer wall profile diameter of the pipe contact portion 212 of the sealing tube 21. An opening 2212 is formed in the radial direction of the elastic retaining ring 221. Multiple openings 2212 are spaced apart along the circumference of the elastic retaining ring 221, and these openings 2212 extend along the axial direction of the elastic retaining ring 221 to maximize the elasticity and expansion space of the elastic retaining ring 221 within its yield limit. In this embodiment, the elastic retaining ring 221 is made of high-strength spring steel. Of course, the elastic retaining ring 221 can also be made of other materials with rebound force within a certain elastic range; this invention does not limit this.

[0059] Furthermore, such as Figure 1 As shown, the difference between the end radius R1 of the elastic retaining ring 221 that contacts the locking member 3 and the inner cavity radius R of the elastic retaining ring 221 is not less than two-thirds of the difference between the outline radius R2 of the elastic retaining ring 221 and the inner cavity radius R of the elastic retaining ring 221, that is, (R1-R) / (R2-R)≥2 / 3, so as to prevent the elastic retaining structure 22 from turning outward when it expands radially due to the excessively small radial difference between the end radius R1 and the outline radius R2 of the elastic retaining ring 221, thereby affecting the anti-push-out performance.

[0060] According to one embodiment of the present invention, along the circumferential direction of the elastic retaining ring 221, the opening directions of two adjacent openings 2212 are arranged in opposite directions.

[0061] Specifically, such as Figures 9 to 12 As shown, along the circumferential direction of the elastic retaining ring 221, the opening directions of two adjacent openings 2212 on the elastic retaining ring 221 are reversed, that is, the opening directions of two adjacent openings 2212 on the elastic retaining ring 221 are radially inward and radially outward, respectively. In this way, the elasticity and expansion space of the elastic retaining ring 221 are improved, and the structural strength of the elastic retaining ring 221 is guaranteed.

[0062] like Figures 1 to 3 , Figure 5 , Figure 9 and Figure 13As shown, according to one embodiment of the present invention, the elastic reset structure 22 further includes at least one first reset spring 222 embedded in the elastic retaining ring 221. Correspondingly, the elastic retaining ring 221 is provided with a first slot 2213 for accommodating the first reset spring 222. The reset spring embedded in the elastic retaining ring 221 assists the elastic retaining ring 221 in rapidly retracting the sealing sleeve 21 radially inward to return it to its initial position. Preferably, as... Figure 5 As shown, to prevent the first return spring 222 from dislodging, an anti-dislodgement surface 22131 is formed by extending the first groove 2213 near the axis of the elastic retaining ring 221 radially outward from the elastic retaining ring 221. This anti-dislodgement surface 22131 has an angle α greater than zero with the axial direction of the elastic retaining ring 221. In this embodiment, the angle α between the anti-dislodgement surface 22131 and the axial direction of the elastic retaining ring 221 is 3°.

[0063] Furthermore, such as Figures 1 to 3 , Figure 9 and Figure 13 As shown, the elastic reset structure 22 also includes at least one second reset spring 223 embedded in the elastic retaining ring 221. The second reset spring 223 is correspondingly embedded in the second slot 2214 on the elastic retaining ring 221. The first slot 2213 and the second slot 2214 are spaced apart radially outward along the elastic retaining ring 221. In this embodiment, the first slot 2213 and the second slot 2214 may be spaced apart radially outward along the elastic retaining ring 221, or they may be spaced apart axially along the elastic retaining ring 221, or they may be spaced apart in both the radial and axial directions of the elastic retaining ring 221.

[0064] Furthermore, the elastic reset structure 22 includes a plurality of first reset springs 222 and a plurality of second reset springs 223 spaced apart along the axial direction of the support cylinder 1, and the elastic retaining ring 221 is provided with a plurality of first slots 2213 and a plurality of second slots 2214 for accommodating the plurality of first reset springs 222 and the plurality of second reset springs 223.

[0065] According to one embodiment of the present invention, the liquid inlet channel 14 is connected to the expansion cavity 211 via the liquid inlet nozzle 4, and the liquid outlet channel 15 is connected to the expansion cavity 211 via the liquid outlet nozzle 5.

[0066] Specifically, such as Figure 1 and Figure 13As shown, the inlet channel 14 is connected to the expansion cavity 211 via the inlet nozzle 4, and the outlet channel 15 is connected to the expansion cavity 211 via the outlet nozzle 5. The connecting part 12 of the support cylinder 1 has two slots 121 formed radially outward to accommodate the inlet nozzle 4 and the outlet nozzle 5, respectively. The two slots 121 are arranged opposite each other along the radial direction of the support cylinder 1, and both slots 121 are conical so that the conical surface of the slot 121 can fit with the conical surface of the inlet nozzle 4 and the outlet nozzle 5. After the inlet nozzle 4 and the outlet nozzle 5 are assembled in place, the surface of the conical part of the inlet nozzle 4 and the outlet nozzle 5 away from the axis of the support cylinder 1 is in close contact with the inner surface of the sealing tube 21, and the surface of the conical part of the inlet nozzle 4 and the outlet nozzle 5 near the axis of the support cylinder 1 is in close contact with the bottom plane of the slot 121. To facilitate venting, the liquid outlet nozzle 5 extends close to the wall of the expansion chamber 211. Before filling the expansion chamber 211 with expansion liquid, the position of the pipe sealing device is adjusted so that the liquid outlet channel 15 faces upward, so as to facilitate the effective discharge of gas in the expansion liquid.

[0067] like Figures 1 to 3 , Figure 6 , Figure 7 and Figure 13 As shown, according to one embodiment of the present invention, a sealing protrusion ring 215 extends radially inward from the inner wall of the sealing tube 21. At least one pair of sealing protrusion rings 215 are symmetrically arranged on the sealing tube 21 along its axial direction. The inlet nozzle 4 and the outlet nozzle 5 are arranged between the at least one pair of sealing protrusion rings 215. In this way, by setting the sealing protrusion rings 215, the pipeline sealing device has the characteristic of self-sealing by expansion. After the sealing tube 21 is sleeved on the support cylinder 1, the sealing protrusion rings 215 on the sealing tube 21 undergo elastic deformation under pressure, and an initial sealing pressure is formed between the sealing protrusion rings 215 and the support cylinder 1. During the expansion filling process, as the internal pressure of the sealing tube 21 increases, the sealing pressure will also increase and exceed the internal pressure of the sealing tube 21, so as to effectively prevent leakage during the process of filling the sealing tube 21 to expand and seal the pipeline 6.

[0068] Furthermore, such as Figure 2 , Figure 3 , Figure 6 and Figure 7 As shown, multiple pairs of sealing protrusions 215 are symmetrically arranged on the sealing tube 21 along its axial direction. The inlet nozzle 4 and outlet nozzle 5 are located at the symmetrical center of the multiple pairs of sealing protrusions 215 to obtain a better sealing effect and prevent the pipe 6 from becoming blocked due to internal pressure relief of the sealing tube 21. In this embodiment, two pairs of sealing protrusions 215 are symmetrically arranged on the sealing tube 21 along its axial direction.

[0069] Preferred, such as Figure 8As shown, the sealing tube 21 has a slit ring 216 formed radially outward at the middle along its axial direction, which communicates with the expansion fluid receiving cavity 211. During the filling of expansion fluid, the expansion fluid enters through the inlet channel 14, part of the expansion fluid enters the expansion fluid receiving cavity 211 through the inlet nozzle 4, and part of the expansion fluid flows from the gap between the inlet nozzle 4 and the groove 121 into the annular cavity formed between the support tube 1 and the two sealing protrusions 215 on both sides of the inlet nozzle 4. Due to the self-sealing characteristics of the expansion fluid, this part of the expansion fluid will not leak, and this part of the expansion fluid will enter the expansion fluid receiving cavity 211 from the slit ring 216. The expansion fluid fills from bottom to top under the action of gravity, and the air inside the sealing tube 21 is discharged from the outlet nozzle 5. The outlet channel 15 initially discharges an oil-gas mixture. When the discharge is all oil, it indicates that the air inside the sealing tube 21 has been discharged.

[0070] After the sealing sleeve 21 and support sleeve 1 of the pipe plugging device with large radial expansion ratio provided by the present invention are assembled in place, an initial contact pressure is formed between the sealing protrusion ring 215 and the support sleeve 1. The initial contact pressure between the sealing protrusion ring 215 and the support sleeve 1 is: P0.

[0071] After the sealing tube 21 is pressurized to P1, the initial contact pressure between the sealing surface of the sealing tube 21 and the inner wall of the pipe 6 is P2.

[0072] The internal pressure of the sealing sleeve 21 gradually increases to P4 under the action of the medium pressure P3 in the pipeline 6;

[0073] The final contact pressure between the sealing protrusion ring 215 and the support cylinder 1 is: P0 + P4;

[0074] The final contact pressure between the sealing surface of the sealing sleeve 21 and the inner wall of the pipe 6 is: P2 + P3.

[0075] Specifically, since the sealing sleeve 21 is provided with multiple pairs of sealing protrusions 215, after the sealing sleeve 21 is assembled with the support sleeve 1, the sealing protrusions 215 are compressed and undergo elastic deformation, forming an initial contact pressure P0 between the sealing protrusions 215 and the support sleeve 1; when the sealing sleeve 21 is pressurized to P1, the sealing sleeve 21 expands and contacts the inner wall of the pipe 6, and the sealing surface of the sealing sleeve 21 undergoes elastic deformation under contact compressive stress, and the inner wall of the pipe 6 generates a certain initial contact pressure P2 on the sealing surface; after the medium pressure P3 of the pipe 6 acts on the high-pressure side of the sealing sleeve 21, the sealing sleeve 21 is squeezed to move towards the low-pressure end, and the elastic deformation further increases. Correspondingly, the internal pressure of the sealing sleeve 21 gradually increases to P4, acting on the sealing sleeve. The contact pressure of the sealing surface of the sealing sleeve 21 rises to P2+P3. Because the contact pressure P2+P3 formed between the sealing surface of the sealing sleeve 21 and the inner wall of the pipe 6 is greater than the medium pressure P3 of the pipe 6, the pipe 6 can be effectively blocked. Therefore, the sealing sleeve 21 has the expansion sealing self-sealing characteristic. At this time, the contact pressure formed between the sealing protrusion ring 215 and the support cylinder 1 is P0+P4. Because the contact pressure P0+P4 formed between the sealing protrusion ring 215 and the support cylinder 1 is greater than the internal pressure P4 of the sealing sleeve 21, the absolute seal of the expansion fluid inside the sealing sleeve 21 can be guaranteed without leakage. Therefore, the setting of the sealing protrusion ring 215 enables the pipe sealing device with a large radial expansion ratio provided by the present invention to have the expansion self-sealing characteristic.

[0076] The above descriptions are merely a few embodiments of the present invention. Those skilled in the art can make various modifications or variations to the embodiments of the present invention based on the content disclosed in the application documents without departing from the spirit and scope of the present invention.

Claims

1. A pipe plugging device with a large radial expansion ratio, characterized in that, include: The support cylinder has a positioning part, a connecting part, and a locking part arranged sequentially along the axial direction. The support cylinder is provided with a liquid inlet channel and a liquid outlet channel that are not interconnected. A sealing mechanism includes a sealing sleeve and an elastic reset structure. The sealing sleeve is sleeved outside the connecting portion. The sealing sleeve has an expansion cavity. The inlet channel is connected to the outlet channel through the expansion cavity. The sealing sleeve extends radially outward to form a pipe contact portion. Both ends of the sealing sleeve have connecting portions extending radially outward. An anti-protrusion portion is formed between the connecting portion and the pipe contact portion. The elastic reset structure is symmetrically arranged on both sides of the expansion cavity. The elastic reset structure is connected to the sealing sleeve through the connecting portion. An anti-protrusion groove corresponding to the anti-protrusion portion is formed on the elastic reset structure. A locking element is sleeved on the locking part, and the locking element is used to axially limit the sealing mechanism; The elastic reset structure can expand radially outward and fit against the inner wall of the pipe to form an expansion seal as the sealing tube is filled with expansion fluid into the expansion cavity through the liquid inlet channel. The elastic reset structure includes an elastic retaining ring with an opening in the radial direction. Multiple openings are spaced apart on the elastic retaining ring along its circumference. The opening directions of two adjacent openings are opposite along the circumference of the elastic retaining ring. The elastic reset structure further includes at least one first reset spring embedded in the elastic retaining ring, and the elastic retaining ring is provided with a first slot for accommodating the first reset spring. The elastic reset structure further includes at least one second reset spring embedded in the elastic retaining ring. The second reset spring is correspondingly embedded in a second slot on the elastic retaining ring. The first slot and the second slot are arranged radially outward along the elastic retaining ring. The sealing rubber sleeve can follow the elastic reset structure as the swollen liquid is discharged from the swollen liquid accommodating cavity to the liquid outlet channel and elastically contract and reset itself radially inward. Along the axial direction of the support cylinder, the contour projection of the pipe contact portion coincides with the contour projection of the elastic reset structure at the location where the anti-protrusion groove is provided.

2. The pipe plugging device with a large radial expansion ratio according to claim 1, characterized in that, The elastic reset structure includes a plurality of first reset springs and a plurality of second reset springs spaced apart along the axial direction of the support cylinder, and the elastic retaining ring is provided with a plurality of first slots and a plurality of second slots for accommodating the plurality of first reset springs and the plurality of second reset springs.

3. The pipe plugging device with a large radial expansion ratio according to claim 1, characterized in that, The liquid inlet channel is connected to the expansion cavity via a liquid inlet nozzle, and the liquid outlet channel is connected to the expansion cavity via a liquid outlet nozzle.

4. The pipe plugging device with a large radial expansion ratio according to claim 3, characterized in that, The inner wall of the sealing tube extends radially inward to form a sealing protrusion ring. At least one pair of sealing protrusion rings are symmetrically arranged on the sealing tube along its axial direction. The liquid inlet nozzle and the liquid outlet nozzle are arranged between at least one pair of sealing protrusion rings.

5. The pipe sealing device with a large radial expansion ratio according to claim 4, characterized in that, After the sealing sleeve and the support sleeve are assembled, the initial contact pressure between the sealing protrusion ring and the support sleeve is: ; The sealing tube is pressurized to... Afterwards, the initial contact pressure between the sealing surface of the sealing sleeve and the inner wall of the pipe is: ; The internal pressure of the sealing sleeve is greater than the pressure of the pipeline medium. Gradually increase under the action to ; The final contact pressure between the sealing protrusion ring and the support cylinder is: ; The final contact pressure between the sealing surface of the sealing tube and the inner wall of the pipe is: .

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