Hole expander and trenchless pipe laying method

Abstract

The present application relates to a reamer and a trenchless pipe laying method, which includes a flattening tube, with reaming tubes fixedly mounted at both ends of the flattening tube, a connecting tube mounted at the end of the reaming tube away from the flattening tube, the inner and outer diameters of the reaming tube decreasing in a tapered manner from the end closest to the flattening tube to the other end, the reaming tube sequentially including a first cutting reaming portion, a second cutting reaming portion, and a flattening reaming portion from the end away from the flattening tube to the other end, the first cutting reaming portion and the second cutting reaming portion both having a plurality of injection holes, a plurality of first cutting rods fixedly mounted on the outer wall of the first cutting reaming portion, a plurality of telescopic holes mounted on the second cutting reaming portion, a second cutting rod being telescopically mounted in each telescopic hole, and a drive assembly being mounted between the second cutting rod and the second cutting reaming portion. The present application has the effect of reducing the occurrence of internal collapse of the guide hole.

Description

Technical Field

[0001] The present application relates to the field of pipeline construction, and in particular to a hole expander and a trenchless pipeline laying method. Background Art

[0002] When laying a pipeline, it may pass through a river or highway. To avoid damaging these channels, trenchless pipe laying methods are often used. In trenchless pipe laying, a drilling rig, using a drill rod, drives the drill bit underground along the pipeline's path to form a pilot hole. As the drill rod drives the drill bit, it also rotates, facilitating the formation of the pilot hole. After the pilot hole is formed, the drill bit is replaced with a reamer. The drill rod then drives the reamer through the pilot hole. The reamer's diameter is larger than the drill bit's. Therefore, as the reamer moves through the pilot hole, it removes soil from the inner wall of the pilot hole, increasing the diameter of the pilot hole.

[0003] Currently, related art discloses a reamer comprising a flattening tube and reaming tubes fixedly mounted at both ends of the flattening tube. Multiple cutting rods are fixedly mounted on the outer wall of the reamer tube, and the reamer tube is also provided with multiple injection holes. The inner and outer diameters of the reamer tube both taper from one end closest to the flattening tube to the other. Connecting tubes are fixedly mounted on the end of the reamer tube away from the flattening tube. One connecting tube is connected to the drill pipe, and the other is connected to the pipeline. During reaming, the drill rig moves the reamer via the drill pipe, which in turn drives the reamer to rotate. As the reamer moves and rotates within the guide hole, the cutting rods remove soil from the inner wall of the guide hole, while mud is sprayed from the injection holes to flush the soil, thereby increasing the diameter of the guide hole to a sufficient diameter for the pipeline. When using a reamer to reame a guide hole, multiple reamers of different diameters are typically used to gradually expand the guide hole, thereby reducing the risk of collapse within the guide hole. The diameter difference between each reamer is related to the hardness of the soil. The harder the soil, the larger the diameter difference between each reamer, and the fewer reamers are needed. The softer the soil, the smaller the diameter difference between each reamer, and the more reamers are needed.

[0004] Regarding the aforementioned related art, the inventors believe that the number of reamers is generally determined based on the overall hardness of the soil along the pipeline's path. The soil along a typical pipeline path varies in softness, with some areas being soft and others being hard. If the hard soil predominates in the pipeline's path, the number of reamers should be adjusted accordingly. As the reamers subsequently expand the guide hole in the soft soil portion, the guide hole may collapse. Summary of the Invention

[0005] In order to reduce the occurrence of internal collapse of the guide hole, the present application provides a hole expander and a trenchless pipeline laying method.

[0006] The present application provides a hole expander and a trenchless pipe laying method, which adopts the following technical solutions:

[0007] The expansion pipe is connected with the expansion pipe of the second end cap and the expansion pipe is connected with the expansion pipe of the second end cap to the expansion pipe of the expansion pipe.

[0008] By adopting this technical solution, the drill rig drives the reamer to move and rotate within the pilot hole via the drill rod. When encountering soft soil, the drive assembly retracts the second cutting rod portion into the reaming tube, depending on the softness of the soil. This reduces the size of the pilot hole expanded by the second cutting reaming portion. The reaming portion is then flattened to compress and expand the soft soil, thereby reducing the risk of the reamer collapsing when expanding the pilot hole in the soft soil.

[0009] When encountering hard soil, the drive assembly extends the second cutting rod according to the hardness of the soil, thereby increasing the size of the second cutting and reaming section's expansion of the guide hole. The flattening and reaming section then squeezes and reams the softer soil, reducing the chance of the flattening and reaming section being unable to flatten due to excessive hardness or volume.

[0010] As the drill rig drives the reamer through the drill pipe and moves and rotates within the pilot hole, the drill rig sprays mud from the two reaming tubes' jet holes. The mud sprayed from the jet holes protects the inner wall of the pilot hole, thereby reducing the risk of collapse within the pilot hole. The mud sprayed from the two reaming tubes' jet holes is sprayed in opposite directions, thus reducing the thrust generated by the mud from the jet holes from hindering the reamer's movement.

[0011] Optionally, the driving assembly includes a guide tube, a guide block and a spring, the guide tube is fixedly mounted on the inner wall of the second cutting and reaming portion, the guide block and the spring are both located inside the guide tube, the spring is located between the guide block and the inner wall of the second cutting and reaming portion, the spring is used to drive the guide block away from the inner wall of the second cutting and reaming portion, the second cutting rod is connected to the guide block at one end facing the interior of the second cutting and reaming portion, and the spring is sleeved on the second cutting rod.

[0012] By adopting the above technical solution, when the reamer encounters a soft soil section, the power of the mud pumped into the reamer is reduced, thereby reducing the pressure inside the reamer. After the pressure inside the reamer is reduced, the spring returns and drives the guide block away from the inner wall of the second cutting and reaming section. The guide block drives the second cutting rod to partially retract into the second cutting and reaming section, thereby conveniently reducing the length of the second cutting rod extending from the telescopic hole. When the reamer encounters a hard soil section, the power of the mud pumped into the reamer is increased, thereby increasing the pressure inside the reamer. After the pressure inside the reamer increases, the guide block is squeezed and moves toward the inner wall of the second cutting and reaming section. The guide block drives the second cutting rod to partially extend out of the second cutting and reaming section, thereby conveniently increasing the length of the second cutting rod extending from the telescopic hole.

[0013] Optionally, the guide block is provided with a plurality of first sealing rings, which are sleeved on the guide block, and a peripheral side wall of the guide block is provided with a groove for the first sealing rings to enter, and the first sealing rings are arranged at intervals along the length direction of the guide tube.

[0014] By adopting the above technical solution, the first sealing ring is used to seal the gap between the peripheral side wall of the guide block and the inner side wall of the guide cylinder, thereby reducing the occurrence of mud intrusion.

[0015] Optionally, an insert block is fixedly mounted on one end of the second cutting rod close to the guide block, and a slot for inserting the insert block is provided on one end of the guide block close to the second cutting rod, and a magnetic block is fixedly mounted on the inner bottom wall of the slot, and the magnetic block is used to attract the insert block.

[0016] By adopting the above technical solution, when the second cutting rod is worn and needs to be replaced, the second cutting rod is pulled out to remove the insert block from the slot, thereby separating the second cutting rod from the guide block. After that, a new second cutting rod is inserted through the telescopic hole, and the insert block is inserted into the slot. The insert block is then attracted by the magnetic block, thereby facilitating the installation and replacement of the second cutting rod.

[0017] Optionally, the guide block is provided with an adjusting column block, and an adjusting slot for the adjusting column block to be threaded through is provided on the side of the guide block close to the second cutting rod, the slot is located in the middle of the inner bottom wall of the adjusting slot, the rod body of the second cutting rod is fixedly installed with a slider, the adjusting column block is provided with a through hole for the second cutting rod to pass through, the inner side wall of the slot and the inner wall of the through hole are both provided with a sliding groove for the slider to slide, and a gap for the slider to enter is left between the adjusting column block and the inner bottom wall of the adjusting slot, and the spring is located between the adjusting column block and the inner wall of the second cutting reaming portion.

[0018] By adopting the above technical solution, the second cutting rod is pulled to allow the slider to enter the gap between the adjusting column block and the inner bottom wall of the adjusting groove, leaving a gap for the slider to enter. The second cutting rod is then rotated to align the slider with the slide groove located on the inner wall of the through hole. The second cutting rod is then pulled again to allow the slider to enter the inside of the slide groove. After the slide enters the inside of the slide groove, the second cutting rod is rotated to engage the slider with the slide groove, thereby rotating the adjusting column block. After the adjusting column block is rotated, the adjusting column block will move along the depth direction of the adjusting groove, thereby changing the distance between the adjusting column block and the inner wall of the second cutting reaming portion, and then adjusting the elastic force of the spring when the mud is not squeezing the guide block. The elastic force of the spring when the mud is not squeezing the guide block is adjustable, thereby facilitating the use of the reamer in laying pipes in soils of different hardness.

[0019] Optionally, a first limit frame is fixedly installed inside the guide tube, a second limit frame is installed at the end of the guide tube away from the second cutting and reaming portion, and the guide block is located between the first limit frame and the second limit frame. The first limit frame and the second limit frame are used to limit the sliding distance of the guide block inside the guide tube.

[0020] By adopting this technical solution, when mud is not being fed into the reamer, the second stopper shields the guide block, thereby reducing the risk of the guide block slipping out of the guide tube. When the pressure of the mud pumped into the reamer reaches a certain level, the guide block abuts against the first stopper, thereby reducing the risk of the spring being damaged by the pressure of the guide block.

[0021] Optionally, a plug-in ring is fixedly installed on the end of the reaming tube close to the flattening tube, the inner diameter of the plug-in ring is equal to the inner diameter of the end of the reaming tube close to the flattening tube, the outer diameter of the plug-in ring is smaller than the outer diameter of the end of the reaming tube close to the flattening tube, and the inner wall of the flattening tube close to the end of the reaming tube is provided with a thread groove for the plug-in ring to be threaded through.

[0022] By adopting the above technical solution, when the reamer needs to be cleaned, the reaming tube is rotated so that the splice ring is pulled out from the threaded groove, thereby facilitating the cleaning of the reamer.

[0023] Optionally, a sleeve is fixedly mounted on the second limiting frame, and the sleeve is threadedly sleeved on an end of the guide tube away from the second cutting and reaming portion.

[0024] By adopting the above technical solution, when cleaning the reamer, the sleeve is rotated, and the sleeve drives the second limit frame to be removed from the guide cylinder, thereby facilitating the removal of the spring and the guide block for cleaning or replacement.

[0025] A trenchless pipeline laying method comprises the following steps: conducting on-site survey to determine the location where the pipeline needs to be laid; excavating working wells at both ends of the location where the pipeline needs to be laid; transporting a drilling rig to a working well, placing a drill rod on the drilling rig, and installing a drill bit at one end of the drill rod; the drilling rig injects mud into the drill rod, and the mud inside the drill rod is continuously ejected from the drill bit, and then the drilling rig drives the drill bit through the drill rod to drill into the inner wall of one working well, and then the drill bit penetrates the inner wall of another working well to form a guide hole; removing the drill bit from the drill rod; preparing multiple reamers with different diameters according to the pipelines to be laid; installing the reamers on the drill rod; the drilling rig drives the reamer to move and rotate in the guide hole through the drill rod to expand the hole; after the diameter of the guide hole increases to be larger than the pipeline to be laid, the pipeline to be laid is installed on the side of the reamer away from the drill rod, and the drilling rig pulls the drill rod, and the drill rod drives the pipeline to be laid into the inside of the guide hole.

[0026] By adopting the above technical solution, mud is sprayed out when the drill bit digs the guide hole and the reamer expands the guide hole, and the inner wall of the guide hole is strengthened by the mud, thereby reducing the occurrence of guide hole collapse.

[0027] Optionally, the drilling rig drives the reamer to move and rotate in the guide hole through the drill rod to expand the hole, including the following steps: when the soil becomes soft, the drive assembly drives the second cutting rod to partially retract into the reaming tube; when the soil becomes hard, the drive assembly drives the second cutting rod to partially extend out of the reaming tube; each reamer is replaced in sequence from large to small according to diameter to expand the hole.

[0028] By adopting the above technical solution, the length of the second cutting rod extending out of the reaming tube is adjusted by the driving assembly according to the softness of the soil, so that the flattening reaming part can squeeze and reame the soft soil part, thereby reducing the occurrence of collapse inside the guide hole.

[0029] In summary, this application includes at least one of the following beneficial technical effects:

[0030] 1. When the soil is soft, the driving assembly drives the second cutting rod to partially retract the second cutting and reaming portion, thereby facilitating the flattening and reaming portion to squeeze and reame the soil on the inner wall of the guide hole, thereby reducing the possibility of collapse inside the guide hole;

[0031] 2. By changing the pressure of the mud inside the reamer, the position of the guide block inside the guide cylinder is changed, thereby facilitating the extension and retraction of the second cutting rod;

[0032] 3. By rotating the adjusting column to extend or retract the adjusting slot, the elastic force of the spring when there is no mud extrusion inside the reamer can be changed, thereby facilitating the reamer to be used for reaming holes in soils of different hardness. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a schematic diagram of the overall structure of the reamer according to an embodiment of the present application without mud inside;

[0034] Figure 2 yes Figure 1 Cross-sectional view at AA;

[0035] Figure 3 yes Figure 2 Enlarged view at point A;

[0036] Figure 4 is an exploded view of a flattened tube and a flared tube according to an embodiment of the present application;

[0037] Figure 5 yes Figure 2 Enlarged view at point B;

[0038] Figure 6 is an exploded view of the second cutting rod and the driving assembly of an embodiment of the present application;

[0039] Figure 7 This is an exploded view of the guide block and the first sealing ring in an embodiment of the present application;

[0040] Figure 8 This is a schematic diagram of using a drilling rig to dig a pilot hole in this application;

[0041] Figure 9 is a schematic diagram of an embodiment of the present application using a first reamer to reame a guide hole;

[0042] Figure 10 This is a schematic diagram of the embodiment of the present application using a second reamer to reame the guide hole

[0043] Figure 11 This is a schematic diagram of pulling the pipe into the guide hole according to an embodiment of the present application.

[0044] Explanation of the accompanying drawings: 1. Flattening tube; 2. Connecting tube; 3. Plug-in ring; 4. Threaded groove; 5. First sealing ring; 6. Second sealing ring; 7. Reaming tube; 71. First cutting and reaming part; 72. Second cutting and reaming part; 73. Flattening and reaming part; 8. First cutting rod; 9. Second cutting rod; 10. Injection hole; 11. Telescopic hole; 12. Drive assembly; 121. Guide tube; 122. Guide block; 123. Spring; 13. Adjustment groove; 14. Slot; 15. Magnetic block; 16. Insert block; 17. Adjustment column block; 18. Drill bit; 19. Through hole; 20. Slider; 21. Slide; 22. Slot; 23. First limit frame; 24. Second limit frame; 25. Sleeve; 26. Drill rig; 27. Pipeline; 28. Drill rod; 29. ​​Guide hole. DETAILED DESCRIPTION

[0045] The following is combined with Figure 1-11 This application is described in further detail.

[0046] The embodiments of the present application disclose a reamer and a trenchless pipeline 27 laying method.

[0047] Reference Figure 1 、 Figure 2 A reamer includes a flattening tube 1. When the flattening tube 1 rotates and moves inside the guide hole 29, the outer wall of the flattening tube 1 remains flat, thereby facilitating the flattening of the inner wall of the guide hole 29.

[0048] Reference Figure 3 、 Figure 4 A reaming tube 7 is provided at both ends of the flattened tube 1. A splice ring 3 is fixedly mounted on the end of the reaming tube 7 closest to the flattened tube 1. The inner diameter of the splice ring 3 is equal to the inner diameter of the end of the reaming tube 7 closest to the flattened tube 1, and the outer diameter of the splice ring 3 is smaller than the outer diameter of the end of the reaming tube 7 closest to the flattened tube 1. A threaded groove 4 is formed on the inner wall of the flattened tube 1 near the end of the reaming tube 7, into which the splice ring 3 is threadedly inserted. The reaming tube 7 is installed in conjunction with the splice ring 3 via the threaded groove 4. When the reamer needs to be cleaned, the reaming tube 7 is unscrewed from the flattened tube 1, making it easier to clean the reamer.

[0049] A second sealing ring 6 is fixedly installed on the side of the plug-in ring 3 away from the reaming pipe 7. After the plug-in ring 3 is screwed into the thread groove 4, the second sealing ring 6 blocks the gap between the plug-in ring 3 and the inner wall of the thread groove 4, thereby reducing mud leakage.

[0050] Reference Figure 1 A connecting pipe 2 is installed at one end of the reaming pipe 7 away from the flattening pipe 1. One end of the connecting pipe 2 away from the reaming pipe 7 is used to connect with the drill rod 28, and the other end of the connecting pipe 2 away from the reaming pipe 7 is used to connect with the pipeline 27.

[0051] Reference Figure 1The inner diameter and outer diameter of the reaming tube 7 gradually increase from one end away from the flattened tube 1 to the other end. The reaming tube 7 includes a first cutting reaming portion 71, a second cutting reaming portion 72 and a flattening reaming portion 73 from one end away from the flattened tube 1 to the other end.

[0052] Reference Figure 1 Both the first cutting and reaming section 71 and the second cutting and reaming section 72 are provided with a plurality of injection holes 10. Slurry within the reamer is ejected through the injection holes 10, protecting the inner wall of the guide hole 29 with the slurry, thereby reducing the risk of collapse within the guide hole 29. Simultaneously, the injection holes 10 located on the two reaming tubes 7 spray in opposite directions, thereby reducing the risk of the injected slurry obstructing the movement of the reamer within the guide hole 29.

[0053] Reference Figure 1 、 Figure 4 The first cutting and reaming section 71 is fixedly mounted with a plurality of first cutting rods 8, and the second cutting and reaming section 72 is provided with a plurality of second cutting rods 9. The second cutting and reaming section 72 is provided with telescopic holes 11 for the second cutting rods 9 to extend and retract. As the reamer moves and rotates within the guide hole 29, the first and second cutting rods 8 and 9 dig down the soil within the guide hole 29, thereby facilitating the expansion of the diameter of the guide hole 29. After the first and second cutting rods 8 and 9 dig down the soil from the inner wall of the guide hole 29, the flattening and reaming section 73 squeezes the inner wall of the guide hole 29 to expand the hole, thereby increasing the hardness of the soil on the inner wall of the guide hole 29 and reducing the risk of collapse within the guide hole 29.

[0054] Reference Figure 5 The second cutting rod 9 is provided with a drive assembly 12, which includes a guide tube 121, a guide block 122, and a spring 123. The guide tube 121 is fixedly mounted on the inner wall of the second cutting and reaming portion 72, and the guide block 122 is slidably disposed inside the guide tube 121. The spring 123 is located between the guide block 122 and the inner wall of the second cutting and reaming portion 72.

[0055] Reference Figure 6 、 Figure 7 An adjustment slot 13 is defined on one side of the guide block 122 near the inner wall of the second cutting and reaming portion 72. A slot 14 is defined in the middle of the bottom of the adjustment slot 13. A magnet 15 is fixedly mounted on the bottom of the slot 14. An insert 16 is fixedly mounted on one end of the second cutting rod 9. The insert 16 is inserted into the slot 14 and attracted by the magnet 15.

[0056] When the second cutting rod 9 is worn and needs to be replaced, the second cutting rod 9 is simply pulled out, thereby removing the insert 16 from the slot 14, making it easier to replace the second cutting rod 9. When a new second cutting rod 9 is to be installed, the second cutting rod 9 is passed through the telescopic hole 11 and the insert 16 is inserted into the slot 14. The insert 16 is attracted by the magnet 15, making it easier to install the second cutting rod 9.

[0057] Reference Figure 6 、 Figure 7 , the guide block 122 is provided with an adjusting column block 17, and the adjusting column block 17 is threadedly penetrated into the adjusting slot 13. The spring 123 is located between the adjusting column block 17 and the inner wall of the second cutting and reaming portion 72. The spring 123 is sleeved on the second cutting rod 9, and the adjusting column block 17 is provided with a through hole 19 for the second cutting rod 9 to pass through. The bearing wall of the insert block 16 is fixedly mounted with a slider 20, and the inner wall of the slot 14 and the inner wall of the through hole 19 are provided with a slide groove 21 for the slider 20 to slide. When the insert block 16 enters the interior of the slot 14, the slider 20 engages with the slide groove 21 located on the inner wall of the slot 14, thereby reducing the rotation of the second cutting rod 9. The spring 123 keeps pushing the adjusting column block 17 away from the inner wall of the second cutting and reaming portion 72.

[0058] When laying the pipeline 27, the initial slurry pumping power is set based on the overall soil hardness along the path of the pipeline 27. The drilling rig 26 then pumps slurry into the reamer via the drill rod 28. The slurry presses against the guide block 122, causing it to move toward the inner wall of the second cutting and reaming portion 72. The guide block 122 then drives the adjustment column 17 to compress the spring 123.

[0059] When the reamer moves from a hard soil area to a soft soil area, the pumping power of the mud is reduced, thereby reducing the mud pressure inside the reamer. As the mud pressure inside the reamer decreases, the spring 123 returns to its original position, causing the guide block 122 to move away from the inner wall of the second cutting and reaming section 72. The second cutting rod 9 retracts partially into the second cutting and reaming section 72, thereby reducing the length of the second cutting rod 9 extending out of the telescopic hole 11. This reduction in the length of the second cutting rod 9 extending out of the telescopic hole 11 reduces the amount of reaming done by the second cutting and reaming section 72 on the guide hole 29, thereby increasing the amount of reaming done by the flattening reaming section 73 on the guide hole 29. By increasing the amount of reaming done by the flattening reaming section 73 on the guide hole 29, the risk of collapse within the guide hole 29 is reduced.

[0060] As the reamer moves from a soft soil area to a hard soil area, the pumping power of the mud increases, thereby increasing the mud pressure inside the reamer. As the mud pressure inside the reamer increases, the guide block 122 continues to move toward the inner wall of the second cutting and reaming section 72. The spring 123 is further compressed by the adjustment column 17, causing the second cutting rod 9 to extend partially outside the second cutting and reaming section 72, thereby increasing the length of the second cutting rod 9 extending out of the telescopic hole 11. This increase in the length of the second cutting rod 9 extending out of the telescopic hole 11 increases the amount of reaming performed by the second cutting and reaming section 72 on the guide hole 29, thereby reducing the amount of reaming performed by the flattening and reaming section 73 on the guide hole 29. By reducing the amount of reaming performed by the flattening and reaming section 73 on the guide hole 29, the power required by the drill rig 26 to propel the reamer through the guide hole 29 is reduced, thereby reducing the risk of the drill rod 28 failing to support the reamer and causing it to break.

[0061] When the reamer is used in different pipeline 27 installations, the overall soil hardness along the installation path varies, resulting in different initial slurry pumping power requirements for the drill rig 26. To use the reamer in different pipeline 27 installations, the second cutting rod 9 is pulled, which pulls the insert 16 out of the slot 14. The slider 20 then moves from the groove 21 on the inner wall of the slot 14 to the gap between the adjustment column 17 and the inner bottom wall of the adjustment slot. The second cutting rod 9 is then rotated to align the slider 20 with the groove 21 on the inner wall of the through hole 19. The second cutting rod 9 is then pulled further to allow the slider 20 to enter the groove 21 on the inner wall of the through hole 19.

[0062] When the slider 20 enters the slot 21 located on the inner wall of the through-hole 19, the second cutting rod 9 rotates, engaging the slider 20 with the slot 21, thereby causing the adjustment column 17 to rotate within the adjustment slot 13. The rotation of the adjustment column 17 within the adjustment slot 13 changes the distance between the adjustment column 17 and the inner wall of the second cutting and reaming portion 72. This change in distance between the adjustment column 17 and the inner wall of the second cutting and reaming portion 72 changes the spring force of the reamer when slurry is not injected. By varying the spring force of the spring 123 when slurry is not injected, the reamer can be used more easily in different road paving applications.

[0063] Reference Figure 5 、 Figure 6 The guide block 122 is square in shape, and the interior of the guide tube 121 is square in cross-section, allowing the guide block 122 to slide. The exterior of the guide tube 121 is round, thereby reducing obstruction to the mud inside the reamer. At the same time, the square interiors of the guide block 122 and the guide tube 121 reduce the possibility of the guide block 122 rotating together when the adjustment column 17 is rotated.

[0064] Reference Figure 5 、 Figure 7 The guide block 122 is provided with a plurality of first sealing rings 5, which are sleeved on the guide block 122. The peripheral sidewall of the guide block 122 is provided with a retaining groove 22 for the first sealing rings 5 ​​to enter. The first sealing rings 5 ​​are arranged at intervals along the length of the guide tube 121. The first sealing rings 5 ​​are used to block the gap between the peripheral sidewall of the guide block 122 and the inner wall of the guide tube 121.

[0065] Reference Figure 5 、 Figure 6 A first limiting frame 23 is fixedly mounted within the guide tube 121. This first limiting frame 23 is located on the side of the guide block 122 near the inner wall of the second cutting and reaming section 72. As the slurry pressure within the reamer increases, the guide block 122 moves toward the inner wall of the second cutting and reaming section 72. When the guide block 122 presses against the first limiting frame 23, it causes the second cutting rod 9 to extend out of the telescopic hole 11 to its maximum length. The first limiting frame 23 then provides a means for the guide block 122 to press against, thereby minimizing the risk of the guide block 122 damaging the spring 123.

[0066] Reference Figure 6 、 Figure 7 The guide tube 121 is provided with a sleeve 25, which is threadedly mounted on the guide tube 121. A second stop frame 24 is fixedly mounted on the end of the sleeve 25 away from the second cutting and reaming portion 72. When there is no mud inside the reamer, the spring 123 returns to its original position, pushing the guide block 122 against the second stop frame 24, thereby reducing the possibility of the guide block 122 moving out of the guide tube 121.

[0067] Reference Figure 8 、 Figure 9 、 Figure 10 、 Figure 11 A trenchless pipeline 27 laying method, using a reamer according to an embodiment of the present application, comprises the following steps:

[0068] S1. Conduct on-site survey to determine the location where the pipeline 27 needs to be laid, and determine the soil softness at each location along the path of the pipeline 27. Then, proceed to step S2.

[0069] S2: Dig working wells at both ends of the location where the pipeline 27 needs to be laid. Then proceed to step S3.

[0070] S3: transport the drilling rig 26 to a working well, with a drill rod 28 placed on the drilling rig 26, and a drill bit 18 installed at one end of the drill rod 28. Then, execute step S4.

[0071] S4: Drilling rig 26 injects mud into drill pipe 28. Mud inside drill pipe 28 is continuously ejected from drill bit 18. Drilling rig 26 then drives drill bit 18 through drill pipe 28 to drill into the inner wall of one working well. Drill bit 18 then penetrates the inner wall of the other working well to form pilot hole 29. Step S5 is then executed.

[0072] The connection between the drill bit 18 and the drill rod 28 is slightly angled, and a detector is installed inside the drill rod 28 to detect rocks in the soil. When a rock is encountered, the drill rig 26 stops driving the drill bit 18 via the drill rod 28 and directs the drill bit 18 in one direction. The drill rig 26 then continues to propel the drill bit 18 through the drill rod 28, allowing the drill bit 18 to move around the rock. After bypassing the rock, the drill rig 26 continues to drive the drill bit 18 through the drill rod 28. After the drill bit 18 enters the inner wall of one working well and exits the inner wall of the other working well, a pilot hole 29 is formed.

[0073] S5: Remove the drill bit 18 from the drill rod 28. Then proceed to step S6.

[0074] S6. Prepare a plurality of reamers with different diameters according to the pipeline 27 to be laid. Then proceed to step S7.

[0075] The diameter of each reamer is larger than the diameter of the pilot hole 29 excavated by the drill bit 18, and the largest reamer is larger than the diameter of the pilot hole 29 required for laying the pipeline 27. The diameter difference between each reamer is determined by the overall soil quality along the pipeline 27 path. The harder the soil, the greater the diameter difference between each reamer, and fewer reamers are required. The softer the soil, the smaller the diameter difference between each reamer, and the more reamers are required.

[0076] S7: Install the reamer on the drill rod 28. Then proceed to step S8.

[0077] S8, the drilling machine 26 drives the reamer to move and rotate in the guide hole 29 through the drill rod 28 to expand the hole, including the following steps:

[0078] S801: When the soil becomes soft, the driving assembly 12 drives the second cutting rod 9 to partially retract into the reaming tube 7. When the soil becomes hard, the driving assembly 12 drives the second cutting rod 9 to partially extend out of the reaming tube 7. Then, step S802 is executed.

[0079] When the soil becomes soft, the drill rig 26 reduces the power of pumping mud, thereby the second cutting rod 9 is partially retracted into the inside of the reaming tube 7. When the soil becomes hard, the drill rig 26 increases the power of pumping mud, thereby the second cutting rod 9 is partially extended out of the inside of the reaming tube 7.

[0080] S802: After a reamer moves from one end of the guide hole 29 to the other end, it is replaced with another reamer with a larger diameter, and then step S801 is executed. After each reamer is used up, the guide hole 29 is expanded to a diameter sufficient for laying the pipe 27, and step S9 is executed.

[0081] S9. Install the pipe 27 to be laid on the side of the reamer away from the drill rod 28. The drill rig 26 pulls the drill rod 28, and the drill rod 28 drives the pipe 27 to be laid into the guide hole 29.

[0082] The operating principle of the reamer and trenchless pipe 27 laying method according to the embodiment of the present application is as follows: When encountering soft soil, the drive assembly 12 drives the second cutting rod 9 to partially retract into the second cutting and reaming portion 72, thereby reducing the size of the second cutting and reaming portion 72 expanding the guide hole 29 and increasing the size of the flattening and reaming portion 73 expanding the guide hole 29, thereby reducing the possibility of collapse within the guide hole 29. When the soil is hard, the drive assembly 12 drives the second cutting rod 9 to partially extend into the second cutting and reaming portion 72, thereby increasing the size of the second cutting and reaming portion 72 expanding the guide hole 29 and decreasing the size of the flattening and reaming portion 73 expanding the guide hole 29, thereby reducing the possibility of excessive power being applied by the drill rig 26 when moving the reamer via the push rod.

[0083] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A hole expander, characterized in that: The invention comprises a flattening tube (1), wherein both ends of the flattening tube (1) are fixedly mounted with reaming tubes (7), and the end of the reaming tube (7) away from the flattening tube (1) is mounted with a connecting tube (2), wherein one end of the connecting tube (2) away from the reaming tube (7) is used for connecting with a drill rod (28), and the other end of the connecting tube (2) away from the reaming tube (7) is used for connecting with a pipe (27), and the inner diameter and the outer diameter of the reaming tube (7) are gradually reduced from one end close to the flattening tube (1) to the other end, forming a conical shape, and the reaming tube (7) includes a first cutting reaming portion (71) in sequence from one end away from the flattening tube (1) to the other end. , a second cutting and reaming portion (72) and a flattening and reaming portion (73), the first cutting and reaming portion (71) and the second cutting and reaming portion (72) are both provided with a plurality of injection holes (10), a plurality of first cutting rods (8) are fixedly mounted on the outer wall of the first cutting and reaming portion (71), the second cutting and reaming portion (72) is provided with a plurality of telescopic holes (11), a second cutting rod (9) is telescopically arranged inside each of the telescopic holes (11), a driving assembly (12) is installed between the second cutting rod (9) and the second cutting and reaming portion (72), the driving assembly (12) being used to drive the second cutting rod (9) to telescope; The driving assembly (12) includes a guide tube (121), a guide block (122) and a spring (123). The guide tube (121) is fixedly mounted on the inner wall of the second cutting and reaming portion (72). The guide block (122) and the spring (123) are both located inside the guide tube (121). The spring (123) is located between the guide block (122) and the inner wall of the second cutting and reaming portion (72). The spring (123) is used to drive the guide block (122) away from the inner wall of the second cutting and reaming portion (72). The end of the second cutting rod (9) facing the inside of the second cutting and reaming portion (72) is connected to the guide block (122), and the spring (123) is sleeved on the second cutting rod (9).

2. A reamer according to claim 1, characterized in that: The guide block (122) is provided with a plurality of first sealing rings (5), the first sealing rings (5) being sleeved on the guide block (122), the peripheral side wall of the guide block (122) being provided with a clamping groove (22) for the first sealing rings (5) to enter, and the first sealing rings (5) being arranged at intervals along the length direction of the guide tube (121).

3. The reamer according to claim 1, characterized in that: An insert block (16) is fixedly mounted on one end of the second cutting rod (9) close to the guide block (122); a slot (14) for inserting the insert block (16) is provided on one end of the guide block (122) close to the second cutting rod (9); a magnetic block (15) is fixedly mounted on the inner bottom wall of the slot (14); and the magnetic block (15) is used to attract the insert block (16).

4. A reamer according to claim 3, characterized in that: The guide block (122) is provided with an adjustment column block (17), and an adjustment groove (13) for the adjustment column block (17) to be threaded is provided on a side of the guide block (122) close to the second cutting rod (9), and the slot (14) is located in the middle of the inner bottom wall of the adjustment groove (13). The rod body of the second cutting rod (9) is fixedly installed with a slider (20), and the adjustment column block (17) is provided with a through hole (19) for the second cutting rod (9) to be threaded. The inner side wall of the slot (14) and the inner wall of the through hole (19) are both provided with a slide groove (21) for the slider (20) to slide. A gap for the slider (20) to enter is left between the adjustment column block (17) and the inner bottom wall of the adjustment groove (13), and the spring (123) is located between the adjustment column block (17) and the inner wall of the second cutting reaming portion (72).

5. The reamer according to claim 1, characterized in that: A first limit frame (23) is fixedly installed inside the guide tube (121), and a second limit frame (24) is installed at one end of the guide tube (121) away from the second cutting and reaming portion (72). The guide block (122) is located between the first limit frame (23) and the second limit frame (24). The first limit frame (23) and the second limit frame (24) are used to limit the sliding distance of the guide block (122) inside the guide tube (121).

6. A reamer according to claim 5, characterized in that: A plug-in ring (3) is fixedly installed on one end of the reaming tube (7) close to the flattening tube (1), the inner diameter of the plug-in ring (3) is equal to the inner diameter of the end of the reaming tube (7) close to the flattening tube (1), the outer diameter of the plug-in ring (3) is smaller than the outer diameter of the end of the reaming tube (7) close to the flattening tube (1), and a thread groove (4) for the plug-in ring (3) to be threaded is provided on the inner wall of the end of the flattening tube (1) close to the reaming tube (7).

7. A reamer according to claim 6, characterized in that: The second limiting frame (24) is fixedly mounted with a sleeve (25), and the sleeve (25) is threadedly sleeved on an end of the guide tube (121) away from the second cutting and reaming portion (72).

8. A trenchless pipeline laying method, using a reamer according to any one of claims 1 to 7 for construction, characterized in that: The following steps are involved: On-site survey to determine the location where the pipeline (27) needs to be laid; excavate working wells at both ends of the location where the pipeline (27) needs to be laid; transport the drilling rig (26) to one working well, place a drill rod (28) on the drilling rig (26), and install a drill bit (18) at one end of the drill rod (28); the drilling rig (26) injects mud into the drill rod (28), and the mud inside the drill rod (28) is continuously ejected from the drill bit (18); then the drilling rig (26) drives the drill bit (18) through the drill rod (28) to drill into the inner wall of one working well, and then the drill bit (18) penetrates the inner wall of the other working well to form a pilot hole (29) ); remove the drill bit (18) from the drill rod (28); prepare a plurality of reamers with different diameters according to the pipe (27) to be laid; install the reamer on the drill rod (28); the drilling rig (26) drives the reamer to move and rotate in the guide hole (29) through the drill rod (28) to expand the hole; after the diameter of the guide hole (29) increases to be larger than the pipe (27) to be laid, the pipe (27) to be laid is installed on the side of the reamer away from the drill rod (28), the drilling rig (26) pulls the drill rod (28), and the drill rod (28) drives the pipe (27) to be laid into the guide hole (29).

9. The trenchless pipeline laying method according to claim 8, characterized in that: The drilling machine (26) drives the reamer to move and rotate in the guide hole (29) through the drill rod (28) to expand the hole, including the following steps: when the soil becomes soft, the driving component (12) drives the second cutting rod (9) to partially retract into the inside of the reaming tube (7); when the soil becomes hard, the driving component (12) drives the second cutting rod (9) to partially extend out of the inside of the reaming tube (7); and each reamer is replaced in order from small to large according to the diameter to expand the hole.

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