Ground directional hole advanced grouting device

Abstract

The invention relates to the technical field of directional hole grouting, and discloses a ground directional hole advanced grouting device which comprises a directional drill bit, a drilling pipe and a drill rod which are connected in sequence, and further comprises a plurality of connecting plates, and a plurality of cutting teeth are fixedly connected to the outer side of each connecting plate at equal intervals. The multiple cutting teeth can rotate along with the drill rod to carry out differential cutting on the inner wall of the directional hole, the plugging mechanism A and the plugging mechanism B each comprise a plugging air bag, the plugging air bags are inflated and expanded through a ventilation pipe to plug a target grouting section, and the multiple gas holes are formed in the outer portion of the drill rod at equal intervals. And the gas holes discharge gas in the target grouting section through an air exhaust mechanism. The technical means that the connecting plate, the plugging mechanism A, the plugging mechanism B and the gas hole are matched is adopted, whole-section cutting is carried out while whole-section drilling is carried out, a segmented advanced grouting method is adopted, and therefore safe and efficient construction of oriented hole advanced grouting in mine water disaster prevention and control is achieved.

Description

Technical Field

[0001] This invention relates to the field of directional hole grouting technology, and more specifically, to a ground directional hole pre-grouting device. Background Technology

[0002] For coal mine water hazards and roadway roof support problems, pre-grouting treatment using directional boreholes on the ground is commonly used. This involves drilling directional boreholes on the ground to the target disaster area underground, and then injecting grout through the boreholes. The grout diffuses and solidifies in the rock fissures or fracture zones, forming a stable water-stopping curtain or roof reinforcement layer, thereby achieving the dual protection goals of water hazard sealing and roof support.

[0003] For example, the patent with patent number "CN110566118B" discloses "a method for advanced grouting modification of the bottom plate of a deep buried aquifer in a coal mine, including the construction of a bottom plate combined directional hole, the bottom plate combined directional hole including a slanting hole section that enters the aquifer from the aquitard and a horizontal hole section that starts from the slanting hole section and extends inside the aquifer...". This patent uses a micro motor and an angle sensor to drive the upper inclined rod to tilt, which can be adjusted without pulling it out.

[0004] However, when the above-mentioned technical solutions use directional drilling tools (mainly composed of directional drill bits, drilling pipes and drill rods) to perform directional hole pre-grouting, they adopt the direct grouting operation method. In the process of rapid diffusion of grout, direct grouting can only achieve surface adhesion with the rock strata, and it is difficult to fully penetrate into the fine cracks to form a mechanical interlocking structure. This results in low bonding strength between the water-stopping layer and the rock strata, thus affecting the effect of pre-grouting for water plugging and reinforcement. Summary of the Invention

[0005] This invention provides a ground-oriented pre-grouting device, which solves the technical problem in related technologies where direct grouting can only achieve surface adhesion to the rock strata during the rapid diffusion of grout, making it difficult to fully penetrate into the fine cracks, resulting in low bonding strength between the waterproof layer and the rock strata, thus affecting the water-blocking and reinforcement effects.

[0006] This invention provides a surface directional borehole pre-grouting device, comprising a directional drill bit, a drilling pipe, and a drill rod connected in sequence, and further comprising:

[0007] Multiple connecting plates are equidistantly arranged on the outside of the drill rod. Each connecting plate has multiple cutting teeth fixedly connected at equal intervals on its outer side. When the drill rod rotates, the multiple cutting teeth can perform differentiated cutting on the inner wall of the directional hole as the drill rod rotates.

[0008] The sealing mechanism A and sealing mechanism B are disposed outside the drill pipe and used to seal the directional hole. Both sealing mechanism A and sealing mechanism B include a sealing airbag embedded outside the drill pipe. The sealing airbag is inflated through the air pipe inside the drill pipe to seal the target grouting section.

[0009] Multiple gas holes are equidistantly opened on the outside of the drill rod and located between two sealing airbags. The gas holes discharge the gas in the target grouting section through the air extraction mechanism.

[0010] Preferably, the drill rod is internally fixedly connected to two limiting cylinders, and each of the two limiting cylinders is internally fixedly connected to multiple elastic telescopic rods at equal intervals. The output end of each elastic telescopic rod passes through the drill rod and is fixedly connected to the corresponding connecting plate.

[0011] Preferably, the plugging mechanism A is located away from the drilling pipe, and the plurality of connecting plates are located outside the plugging mechanism A. In the initial state, the plurality of connecting plates are in contact with the plugging airbag in the plugging mechanism A.

[0012] Preferably, a return spring is provided between the outer and inner layers of the sealing airbag, the inner layer of the sealing airbag is attached to the outside of the drill pipe, and the outer layer of the sealing airbag can be radially extended and retracted.

[0013] Preferably, when the sealing airbag in the sealing mechanism A expands radially, it can push the multiple connecting plates against the inner wall of the directional hole, so that the multiple cutting teeth can be inserted into the inner wall of the directional hole to limit the axial movement of the drill rod.

[0014] Preferably, the gas holes are all inclinedly opened on the drill pipe, with one end of the gas holes extending into the drill pipe close to the drilling pipe and the other end of the gas holes extending out of the drill pipe away from the drilling pipe.

[0015] Preferably, the air extraction mechanism includes an annular chamber fixedly connected inside the drill pipe, the annular chamber being connected to multiple gas holes, and an air extraction pipe located inside the drill pipe being fixedly connected to the outside of the annular chamber.

[0016] Preferably, the annular chamber and the two limiting cylinders are all connected to a transition sleeve at the end away from the drilling pipe, and the inner diameter of the transition sleeve gradually increases in the opposite direction of grouting.

[0017] Preferably, both the extraction pipe and the ventilation pipe extend to the outside of the drill pipe, and both the extraction pipe and the ventilation pipe are equipped with a switch valve.

[0018] The beneficial effects of this invention are as follows:

[0019] 1. This invention employs a technical approach that combines a connecting plate, a sealing mechanism A, a sealing mechanism B, and a gas hole. It performs full-section cutting while drilling the entire section and adopts a segmented advanced grouting method. This involves the operation of primary sealing and limiting, gas extraction, and secondary sealing and grouting during segmented advanced grouting, thereby enabling safe and efficient construction of directional hole advanced grouting in mine water hazard prevention.

[0020] 2. In the present invention, during directional drilling, the drilling rig is started to make the directional drill bit, the drilling pipe and the drill rod rotate and drill along a preset trajectory. At the same time, the connecting plate outside the drill rod rotates synchronously with the drill rod, so that multiple cutting teeth perform differentiated cutting on the inner wall of the directional hole throughout the entire section, so that the inner wall of the directional hole forms a rough structure surface with alternating concave and convex surfaces, thereby increasing the contact area and embedding effect of the grout between the grout and the rock mass in the subsequent grouting operation, laying a structural foundation for improving the reinforcement effect of the subsequent grouting.

[0021] 3. During the first sealing operation, the sealing airbag in the sealing mechanism A is inflated. The radial thrust generated by the inflation of the sealing airbag allows multiple cutting teeth to be fully inserted into the rock mass inside the directional hole, forming a mechanical interlocking structure. After the first sealing of the target grouting section is completed, it can provide an operational basis for subsequent gas extraction. The formed mechanical interlocking structure can effectively counteract the axial reaction force applied to the drill rod by the high-pressure grout during subsequent grouting operations, prevent the drill rod from moving axially, and ensure the stable transmission of grouting pressure.

[0022] 3. In the gas extraction operation, the present invention uses a negative pressure device to collect the gas in the target grouting section into the annular chamber through inclined gas holes, and then extracts it through the extraction pipe, so as to avoid a large amount of gas remaining in the target grouting section, which would cause bubble-type pore defects in the water-proof layer, thereby improving the bonding strength and compactness of the water-proof layer and the rock strata.

[0023] 4. During the secondary sealing process, the present invention inflates the sealing airbag in sealing mechanism B, enabling the sealing airbag in sealing mechanism B to complete the secondary sealing of the target grouting section, providing an operational basis for subsequent high-pressure grouting, while blocking multiple gas holes to prevent grout from flowing back into multiple gas holes during high-pressure grouting, thus avoiding blockage of multiple gas holes and ensuring the repetitive operation of gas extraction. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0025] Figure 2 This is a partial structural schematic diagram of the present invention;

[0026] Figure 3 This is a schematic diagram of the connecting plate in this invention;

[0027] Figure 4This is a schematic diagram of the sealing mechanism A in this invention;

[0028] Figure 5 This is a schematic diagram of the annular compartment in this invention.

[0029] In the diagram: 100, directional drill bit; 200, drilling casing; 300, drill pipe; 400, connecting plate; 410, cutting teeth; 420, limiting sleeve; 430, elastic telescopic rod; 500, plugging mechanism A; 600, plugging mechanism B; 561, plugging airbag; 562, vent pipe; 700, gas hole; 710, annular chamber; 720, extraction pipe; 800, transition sleeve. Detailed Implementation

[0030] The subject matter described herein will now be discussed with reference to exemplary embodiments. It should be understood that these embodiments are discussed only to enable those skilled in the art to better understand and implement the subject matter described herein, and changes may be made to the function and arrangement of the elements discussed without departing from the scope of this specification. Various processes or components may be omitted, substituted, or added as needed in the examples. Furthermore, some features described in the examples may be combined in other examples.

[0031] like Figure 1 - Figure 2 As shown, this embodiment provides a ground directional borehole pre-grouting device, including a directional drill bit 100, a drilling pipe 200, and a drill rod 300 connected in sequence. The directional drill bit 100, the drilling pipe 200, and the drill rod 300 are conventional components that can be adapted to ground directional drilling operations. Their specific structures and basic principles are common knowledge to those skilled in the art, so they will not be described in detail in this embodiment. It also includes multiple connecting plates 400, a sealing mechanism A500, a sealing mechanism B600, and multiple gas holes 700. When drilling directional holes, the multiple connecting plates 400 can rotate with the drill rod 300 to perform differentiated cutting on the inner wall of the directional hole. At the same time, the multiple connecting plates 400 can axially limit the drill rod 300 through the sealing mechanism A500. The sealing mechanism B600 can seal the target grouting section. The multiple gas holes 700 can extract gas in the target grouting section with the cooperation of the sealing mechanism A500.

[0032] Among them, specifically such as Figure 3As shown, multiple connecting plates 400 are equidistantly arranged outside the drill rod 300. Each connecting plate 400 has multiple cutting teeth 410 fixedly connected at equal intervals on its outer side. When the directional drill bit 100, the drilling pipe 200 and the drill rod 300 rotate to drill directional holes, the multiple cutting teeth 410 can rotate with the drill rod 300 to perform differentiated cutting on the inner wall of the directional hole, so that the inner wall of the directional hole forms a rough structure surface with alternating concave and convex features. This increases the contact area and embedding effect between the grout and the rock mass of the inner wall of the directional hole in the subsequent grouting operation, laying a structural foundation for the subsequent improvement of the grouting reinforcement effect.

[0033] Two limiting cylinders 420 are fixedly connected inside the drill pipe 300. The ends of the two limiting cylinders 420 away from the drilling pipe 200 are connected to transition sleeves 800. The inner diameter of the transition sleeves 800 gradually increases in the opposite direction of grouting to form a flared flow guiding structure, which buffers and guides the grout entering the limiting cylinder 420, preventing the grout from directly impacting the end of the limiting cylinder 420 and causing wear. Multiple elastic telescopic rods 430 are fixedly connected at equal intervals inside the two limiting cylinders 420. The output end of each elastic telescopic rod 430 passes through the drill pipe 300 and is fixedly connected to the corresponding connecting plate 400. The elastic telescopic rods 430 are used to limit the radial expansion and contraction of the corresponding connecting plate 400. The radially expanding connecting plate 400 can drive multiple cutting teeth 410 on its outside to insert into the inner wall of the directional hole to limit the axial movement of the drill pipe 300.

[0034] Among them, specifically such as Figure 4 As shown, sealing mechanisms A500 and B600 are located outside the drill pipe 300 and are used to seal the directional hole. Sealing mechanism A500 is located away from the drilling pipe 200. Both sealing mechanisms A500 and B600 include sealing airbags 561 embedded outside the drill pipe 300. Multiple connecting plates 400 are located outside sealing mechanism A500. In the initial state, the multiple connecting plates 400 are in contact with the sealing airbags 561 in sealing mechanism A500. A return spring is provided between the outer and inner layers of the sealing airbag 561, and the return spring extends along the circumference of the sealing airbag 561. The airbags are evenly distributed in a mesh pattern along the direction and axis, which does not affect the inflation and deflation of the sealing airbags 561, and can also provide elastic support and guidance for the outer layer of the sealing airbags 561. The inner layer of the sealing airbags 561 is attached to the outer side of the drill rod 300, and the outer layer of the sealing airbags 561 can expand and contract radially. When inflated, the return spring extends outward synchronously with the outer layer of the sealing airbags 561. When depressurized, the return spring causes the outer layer of the sealing airbags 561 to return to its original position synchronously. The sealing airbags 561 are inflated and expanded through the air pipe 562 inside the drill rod 300 to seal the target grouting section.

[0035] The vent pipe 562 extends to the outside of the drill pipe 300 and connects to an external air source device. A switch valve is installed on the outside of the vent pipe 562. By controlling the opening and closing of the switch valve, the inflation and expansion of the sealing airbag 561 can be achieved, as well as the exhaust and contraction reset. Specifically, when the target grouting section needs to be sealed, the switch valve is opened and a high-pressure air source is connected. The high-pressure gas enters the chamber between the inner and outer layers of the sealing airbag 561 through the vent pipe 562, pushing the outer layer of the sealing airbag 561 to expand radially until it presses against the inner wall of the directional hole to form a reliable sealing structure. The exhaust and contraction reset operation is the same.

[0036] When the sealing airbag 51 in the sealing mechanism A500 expands radially, it can push multiple connecting plates 400 against the inner wall of the directional hole, causing multiple cutting teeth 410 to insert into the inner wall of the directional hole and axially limit the drill rod 300. Specifically, the radial thrust generated by the inflation of the sealing airbag 561 can be transmitted to the connecting plate 400, causing the connecting plate 400 to drive the cutting teeth 410 to move outward synchronously until the cutting teeth 410 are completely inserted into the rock mass of the inner wall of the directional hole. At this time, a mechanical interlocking structure is formed between the cutting teeth 410 and the rock mass of the inner wall of the directional hole, which can effectively counteract the axial reaction force applied to the drill rod 300 by the high-pressure grout during the grouting operation, prevent the drill rod 300 from axially moving, and ensure the stable transmission of grouting pressure.

[0037] Multiple gas holes 700 are equidistantly located outside the drill pipe 300 and between two sealing airbags 561. These gas holes 700 discharge gas from the target grouting section via an extraction mechanism. If a large amount of gas remains in the target grouting section, the high-pressure grout will be blocked by the gas during injection, preventing it from fully penetrating into the rock fissures. Simultaneously, the gas trapped between the grout and the inner wall of the directional hole will form bubble-type pore defects, reducing the bond strength and density between the grout and the formation rock mass. All gas holes 700 are inclinedly opened on the drill pipe 300. One end of the gas holes 700 extending into the drill pipe 300 is close to the drilling pipe 200, and the other end of the gas holes 700 extending out of the drill pipe 300 is away from the drilling pipe 200. The inclined design of the gas holes 700 makes their outer ports face away from the drilling direction, so that the flow direction of the cuttings fluid generated during drilling is opposite to the opening direction of the gas holes 700, thereby greatly reducing the probability of cuttings fluid entering the gas holes 700 and causing blockage.

[0038] The air extraction mechanism includes an annular chamber 710 fixedly connected inside the drill pipe 300. The annular chamber 710 is connected to multiple gas holes 600. The end of the annular chamber 710 away from the drilling pipe 200 is connected to a transition sleeve 800. The inner diameter of the transition sleeve 800 gradually increases in the opposite direction of grouting to form a flared flow guiding structure, which buffers and guides the grout entering the annular chamber 710 to prevent the grout from directly impacting the end of the annular chamber 710 and causing wear. The annular chamber 710 is fixedly connected to an air extraction pipe 720 located inside the drill pipe 300.

[0039] The extraction pipe 720 extends to the outside of the drill rod 300 and connects to the external negative pressure equipment. A switch valve is installed on the outside of the extraction pipe 720. By opening and closing the switch valve, the gas extraction operation can be precisely started and stopped. After the sealing airbag 561 in the sealing mechanism A500 is inflated and sealed to the target grouting section, the switch valve is opened and the negative pressure equipment is started. The gas in the target grouting section is collected in the annular chamber 710 through multiple gas holes 700 and then extracted to the ground safety area by the extraction pipe 720. After the gas concentration is detected to meet the standard, the switch valve is closed and the negative pressure equipment is cut off, and the subsequent grouting process can be started.

[0040] The specific working principle of this implementation is as follows: The core working logic of this implementation is to perform differentiated cutting on the inner wall of the directional borehole while drilling, that is, to perform full-section cutting while drilling the entire section. When grouting in the directional borehole, a segmented advanced grouting method is adopted. That is, while performing the first sealing in segments, axial limiting can be performed, followed by gas extraction. After the second sealing in segments, grouting of the target grouting section can be performed. The first sealing limiting, gas extraction, and second sealing grouting of the next segment are operated in the same way. That is, through the coordinated cooperation of the connecting plate 400, the sealing mechanism A500, the sealing mechanism B600 and the gas hole 700, safe and efficient construction of advanced grouting of directional boreholes in mine water hazard prevention can be achieved.

[0041] Directional drilling and full-section cutting of the borehole wall are carried out simultaneously: By starting the drilling rig, the directional drill bit 100, the drilling pipe 200, and the drill rod 300 rotate and drill along the preset trajectory. While completing the directional hole formation, the connecting plates 400, which are equidistantly arranged on the outside of the drill rod 300, rotate synchronously with the drill rod 300. The multiple cutting teeth 410 on the outside of the connecting plates perform differentiated cutting on the inner wall of the directional hole, so that the inner wall of the directional hole forms a rough structure surface with alternating concave and convex surfaces. This synchronous operation method does not require additional borehole wall treatment procedures and can directly increase the contact area and embedding effect between the grout and the rock mass in the subsequent grouting operation, laying a structural foundation for improving the reinforcement effect of subsequent grouting.

[0042] The sealing and axial limiting linkage operation is as follows: By opening the switch valve to connect the high-pressure air source, the sealing airbag 561 in the sealing mechanism A500 is inflated. The high-pressure gas enters the chamber between the inner and outer layers of the sealing airbag 561 through the vent pipe 562, pushing the outer layer of the sealing airbag 561 to expand radially, causing the sealing airbag 561 to inflate. The radial thrust generated by the inflation of the sealing airbag 561 can be transmitted to the connecting plate 400, causing the connecting plate 400 to drive the cutting teeth 410 to move outward synchronously. The outer layer of the sealing airbag 561 is pressed against the directional hole. When the wall is being sealed, the inflation operation of the sealing mechanism A500 is stopped. At this time, the cutting teeth 410 are fully inserted into the rock mass inside the directional hole to form a mechanical interlocking structure. After the sealing airbag 561 in the sealing mechanism A500 completes the first sealing of the target grouting section, it can provide an operational basis for subsequent gas extraction. After the cutting teeth 410 are inserted into the rock mass inside the directional hole to form a mechanical interlocking structure, they can effectively offset the axial reaction force applied to the drill rod 300 by the high-pressure grout in the subsequent grouting operation, prevent the drill rod 300 from axially moving, and ensure the stable transmission of grouting pressure.

[0043] Gas extraction operation: By opening the switch valve and starting the external negative pressure equipment, the gas in the target grouting section is collected in the annular chamber 710 through the inclined gas holes 700, and then extracted to the ground safety area by the extraction pipe 720. After the gas concentration drops to the safe threshold, the switch valve and negative pressure equipment are closed to prevent a large amount of residual gas in the target grouting section from causing bubble-type pore defects in the waterproof layer, thereby improving the bonding strength and compactness of the waterproof layer and the rock strata.

[0044] Secondary sealing and high-pressure grouting operation: By opening the switch valve to connect the high-pressure air source, the sealing airbag 561 in the sealing mechanism B600 is inflated. Similarly, the sealing airbag 561 in the sealing mechanism B600 completes the secondary sealing of the target grouting section. After the sealing airbag 561 in the sealing mechanism B600 completes the secondary sealing of the target grouting section, it can provide an operational basis for subsequent high-pressure grouting. At the same time, it can block multiple gas holes 700 to prevent grout from flowing back into multiple gas holes 700 during the high-pressure grouting process, so as to avoid blockage of multiple gas holes 700 and thus ensure the repetition of gas extraction operation. Subsequently, high-pressure grout can be injected into the target grouting section through the grouting channel inside the drill rod 300, so that the grout can fully penetrate into the rough cracks of the directional hole wall and the rock mass fissures in the sealed space, forming a high-strength grouting water-proof layer.

[0045] After completing the first sealing limit, gas extraction, and second sealing grouting operations for this section, control the two sealing airbags 561 to depressurize and contract, releasing the sealing of the target grouting section. At the same time, the elastic telescopic rod 430 pulls the connecting plate 400 back to its original position. Then, control the directional drill bit 100, the drilling pipe 200, and the drill rod 300 to retract to the next target grouting section for the first sealing limit, gas extraction, and second sealing grouting operations. Repeat the first sealing limit, gas extraction, and second sealing grouting operations until the pre-grouting operation of the entire hole section is completed.

[0046] The embodiments of the present invention have been described above, but the embodiments are not limited to the specific implementation methods described above. The specific implementation methods described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the embodiments described above, all of which are within the protection scope of the embodiments described above.

Claims

1. A surface directional borehole pre-grouting device, comprising a directional drill bit (100), a drilling pipe (200), and a drill rod (300) connected in sequence, characterized in that, Also includes: Multiple connecting plates (400) are equidistantly arranged outside the drill rod (300). Each connecting plate (400) has multiple cutting teeth (410) fixedly connected at equal intervals on its outer side. When the drill rod (300) rotates, the multiple cutting teeth (410) can perform differentiated cutting on the inner wall of the directional hole as the drill rod (300) rotates. The sealing mechanism A (500) and sealing mechanism B (600) are disposed outside the drill rod (300) and used to seal the directional hole. Both the sealing mechanism A (500) and the sealing mechanism B (600) include a sealing airbag (561) embedded outside the drill rod (300). The sealing airbag (561) is inflated by the air pipe (562) inside the drill rod (300) to seal the target grouting section. Multiple gas holes (700) are equidistantly opened outside the drill rod (300) and located between two sealing airbags (561). The gas holes (700) discharge gas in the target grouting section through the air extraction mechanism.

2. The ground directional hole pre-grouting device according to claim 1, characterized in that, The drill rod (300) is internally fixedly connected to two limiting cylinders (420). Each of the two limiting cylinders (420) is internally fixedly connected to multiple elastic telescopic rods (430) at equal intervals. The output end of each elastic telescopic rod (430) passes through the drill rod (300) and is fixedly connected to the corresponding connecting plate (400).

3. The ground directional hole pre-grouting device according to claim 2, characterized in that, The plugging mechanism A (500) is located away from the drilling pipe (200), and the plurality of connecting plates (400) are located outside the plugging mechanism A (500). In the initial state, the plurality of connecting plates (400) are in contact with the plugging airbag (561) in the plugging mechanism A (500).

4. The ground directional hole pre-grouting device according to claim 3, characterized in that, A return spring is provided between the outer and inner layers of the sealing airbag (561). The inner layer of the sealing airbag (561) is attached to the outside of the drill pipe (300), and the outer layer of the sealing airbag (561) can be radially extended and retracted.

5. A ground directional hole pre-grouting device according to claim 4, characterized in that, When the sealing airbag (51) in the sealing mechanism A (500) expands radially, it can push multiple connecting plates (400) against the inner wall of the directional hole, so that multiple cutting teeth (410) can be inserted into the inner wall of the directional hole to perform axial positioning of the drill rod (300).

6. The ground directional hole pre-grouting device according to claim 5, characterized in that, Multiple gas holes (700) are obliquely opened on the drill pipe (300). One end of the multiple gas holes (700) extends into the drill pipe (300) and is close to the drilling pipe (200). The other end of the multiple gas holes (700) extends out of the drill pipe (300) and is away from the drilling pipe (200).

7. A ground directional hole pre-grouting device according to claim 6, characterized in that, The air extraction mechanism includes an annular chamber (710) fixedly connected inside the drill rod (300), the annular chamber (710) being connected to a plurality of gas holes (600), and an air extraction pipe (720) located inside the drill rod (300) being fixedly connected to the outside of the annular chamber (710).

8. A ground directional hole pre-grouting device according to claim 7, characterized in that, The annular chamber (710) and the two limiting cylinders (420) are all connected to a transition sleeve (800) at the end away from the drilling pipe (200), and the inner diameter of the transition sleeve (800) gradually increases in the opposite direction of grouting.

9. A ground directional hole pre-grouting device according to claim 8, characterized in that, Both the extraction pipe (720) and the ventilation pipe (562) extend to the outside of the drill pipe (300), and both the extraction pipe (720) and the ventilation pipe (562) are equipped with switching valves.

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