KR102271372B1 - Drilling apparatus with jet grouting - Google Patents

Abstract

The present invention relates to a drilling apparatus capable of jet grouting and, more specifically, to a drilling apparatus capable of jet grouting which can supply a high-pressure grouting material and high-pressure air for operating a piston through divided flow paths in a casing, prevent a nozzle for grouting material injection from being exposed to the outside during a drilling process, and expose the nozzle only during a process of injecting the high-pressure grouting material. To this end, according to one aspect of the present invention, the drilling apparatus capable of jet grouting comprises: a drill bit drilling the ground; a piston mounted to ascend and descend to apply an impact to the drill bit; a piston driving unit supplying compressed air to lift and lower the piston; a casing formed to enclose an upper portion of the drill bit, the piston, and the piston driving unit; an internal flow path formed to inject a grouting material after the grouting material is supplied up to the drill bit; and an external flow path formed and separated from the internal flow path and formed to inject compressed air to a lower portion of the drill bit.

Description

DRILLING APPARATUS WITH JET GROUTING

The present invention relates to a drilling device capable of jet grouting, and more particularly, it is possible to supply high-pressure air and high-pressure grouting material for operating a piston through a flow path partitioned inside the casing, and grouting material is injected during the drilling process. It relates to a drilling device capable of jet grouting, in which the nozzle is not exposed to the outside, and the nozzle can be exposed to the outside only during the process of injecting the high-pressure grouting material.

In general, if the stratum at the location where the tunnel is constructed forms sandy soil, gravel, sand-gravel layer, or a fault fracture zone, when a stress relaxation zone occurs by forming an underground cavity in the ground during tunnel construction, the self-reliance of the ground is low or Due to the lack of it, the risk of ground collapse or collapse is high, so proper grouting work is required.

In particular, when the groundwater level around the tunnel is high, so groundwater leakage is expected and there is a risk of ground collapse or collapse, or the surface from the location where the underground tunnel is to be excavated to the adjacent surface is thin and there are many existing structures on the ground. When damage to ground structures is expected due to subsidence caused by tunnel excavation, excavating the tunnel in the ground is very difficult and unstable, so grouting work that can minimize the formation of relaxation zones around the tunnel is urgently needed.

A conventional drilling device for this purpose is provided with a drill bit for ground drilling, and a piston for applying an impact to the drill bit, and the upper part of the drill bit and the piston are disposed inside the casing so as not to be damaged in the drilling process.

In addition, in order to spray the high-pressure grouting material to the surrounding ground through the drilling device, the conventional drilling device forms a channel for supplying the grouting material to the casing, and the channel is formed so that it communicates with the nozzle installed outside the casing. After that, it is configured so that the jet grouting operation can proceed.

However, in this conventional drilling device, as a channel for grouting material injection is formed in the expensive casing, the durability of the casing itself is lowered, and thus the expensive casing is damaged in the drilling process. As such, when the expensive casing is damaged and the casing needs to be replaced, the piston inside the casing and all parts for driving the casing must be reinstalled, so there is a problem of high cost.

In addition, as the nozzle is installed to be exposed on the outer circumferential surface of the casing, the nozzle is easily damaged by an external force applied during the drilling process, and thus, there is a problem in that it is not easy to spray the high-pressure grouting material for jet grouting.

Therefore, there is a need for improvement of these problems.

Korean Patent Publication No. 10-2011-0134880 (published on December 15, 2011)

The technical problem to be solved in the present invention is to provide a drilling device capable of jet grouting capable of supplying high-pressure air and high-pressure grouting material for operating the piston through the passages respectively partitioned inside the casing.

In addition, it is to provide a drilling apparatus capable of jet grouting in which the nozzle for injection of the grouting material is not exposed to the outside during the drilling process, and the nozzle is exposed to the outside only during the process of injecting the high-pressure grouting material.

Technical problems to be solved in the present invention are not limited thereto, and other technical problems not mentioned will be clearly understood by those skilled in the art from the following description.

Jet grouting drilling device capable of jet grouting according to an aspect of the present invention for solving the above technical problem is a drill bit for drilling the ground, a piston that is mounted so as to apply an impact to the drill bit, and a piston that is mounted to enable a lowering operation, the piston A piston driving unit for supplying compressed air for this upward or downward operation, an upper portion of the drill bit, a casing formed to surround the piston and the piston driving unit, and an interior formed to be sprayed after the grouting material is supplied to the drill bit It includes a flow path, and an external flow path formed to be partitioned with the inner flow path, and configured to inject compressed air into a lower portion of the drill bit.

At this time, the inner flow path may be formed to extend to the inner peripheral surface of the piston driving part, the inner peripheral surface of the piston, and the inner peripheral surface of the drill bit.

At this time, the inner peripheral surface of the piston driving part, the inner peripheral surface of the piston, and the inner peripheral surface of the drill bit are provided with at least one inner tube extending along the axial direction, the inner flow path may be formed inside the inner tube have.

In this case, the drill bit may be provided with a nozzle to which the grouting material is sprayed, and the drill bit may be provided with a connection passage for communicating the inner passage with the nozzle.

In this case, the external flow path may be formed to extend between the piston driving unit and the casing, between the piston and the casing, and between the upper portion of the drill bit and the casing, respectively.

At this time, an air passage is formed in the drill bit so that compressed air supplied through the external passage formed between the upper portion of the drill bit and the casing is sprayed to the lower portion of the drill bit, and the air passage is sprayed through the air passage. The compressed air may move so that the sludge is discharged through the discharge space formed between the perforated hole and the outer circumferential surface of the casing.

At this time, the casing is disposed to surround the outside of the nozzle to prevent the nozzle from being exposed to the outside when the ground is drilled, and the casing can be moved upward a certain distance so that the nozzle is exposed to the outside when the grouting material is sprayed after the ground drilling. have.

In this case, the casing and the drill bit may be slidably mounted while moving relative to each other so that the position of the drill bit is constantly maintained while the casing moves upward by a predetermined distance.

At this time, the position of the drill bit may be constantly maintained by its own weight when the casing moves upward.

At this time, a protrusion extending outward in a radial direction is formed on the upper end of the drill bit, and a locking part caught on the protrusion when the case moves upward is formed on the inner circumferential surface of the casing in a radial direction, and the protrusion and The engaging parts may be spaced apart by a predetermined distance.

In this case, the inner tube includes a first tube disposed inside the drill bit, a second tube disposed inside the piston to communicate with the first tube, and the inside of the piston driving unit to communicate with the second tube. It may include a third tube disposed in the.

In this case, the first tube may be provided with a sealing portion for sealing between the first tube and the second tube, and the sealing portion may be disposed upward by a sealing distance from the lower end of the second tube when the ground is drilled.

The drilling device capable of jet grouting of the present invention having the above configuration can supply high-pressure air and high-pressure grouting material for operating the piston through each partitioned flow path inside the casing, thereby effectively preventing deterioration of the durability of the casing and thus the construction cost savings are possible.

In addition, since the nozzle for injection of the grouting material is not exposed to the outside during the drilling process, and the nozzle is exposed to the outside only during the process of injecting the high-pressure grouting material, the high-pressure injection of the grouting material for the jet grouting can proceed smoothly. .

It should be understood that the effects of the present invention are not limited to the above-described effects, and include all effects that can be inferred from the configuration of the invention described in the detailed description or claims of the present invention.

1 is a perspective view showing a drilling device capable of jet grouting according to the present invention, a view showing a ground drilling state.
Figure 2 is a cross-sectional view showing a drilling device capable of jet grouting according to the present invention, a view showing a ground drilling state.
3 is an enlarged cross-sectional view illustrating a state in which the punched bit of FIG. 2 is coupled.
4 is a perspective view showing a punched bit according to the present invention.
Figure 5 is a perspective view showing a drilling device capable of jet grouting according to the present invention, a view showing a grouting material injection state.
Figure 6 is a cross-sectional view showing a drilling device capable of jet grouting according to the present invention, a view showing a grouting material injection state.
7 is an enlarged cross-sectional view illustrating a state in which the punched bit of FIG. 6 is coupled.

Hereinafter, with reference to the accompanying drawings, the embodiments of the present invention will be described in detail so that those of ordinary skill in the art to which the present invention pertains can easily implement them. The present invention may be embodied in many different forms and is not limited to the embodiments described herein. In order to clearly explain the present invention in the drawings, parts irrelevant to the description are omitted, and the same reference numerals are assigned to the same or similar components throughout the specification.

In the present specification, terms such as “comprise” or “have” are intended to designate that a feature, number, step, operation, component, part, or combination thereof described in the specification exists, but one or more other features It is to be understood that it does not preclude the possibility of the presence or addition of numbers, steps, operations, components, parts, or combinations thereof.

Figure 1 is a perspective view showing a drilling device capable of jet grouting according to the present invention, a view showing a ground drilling state, Figure 2 is a cross-sectional view showing a drilling device capable of jet grouting according to the present invention, ground drilling state 3 is an enlarged cross-sectional view showing a state in which the punching bit of FIG. 2 is coupled, FIG. 4 is a perspective view showing a punching bit according to the present invention, and FIG. 5 is a jet grouting according to the present invention As a perspective view showing a possible drilling device, a view showing a grouting material injection state, Figure 6 is a cross-sectional view showing a drilling device capable of jet grouting according to the present invention, a view showing the grouting material injection state, Figure 7 is an enlarged cross-sectional view illustrating a state in which the punching bit of FIG. 6 is coupled.

As shown in Figure 1, the drilling device capable of jet grouting according to the present invention is provided with a drill bit 100 for drilling the ground (G), and a piston 200 for applying an impact to the drill bit 100. The configuration of the back is disposed inside the casing 400 . That is, when an impact is applied to the drill bit 100, the perforation is possible while the impact is transmitted to the ground (G).

Figure 2 is a cross-sectional view showing a drilling device capable of jet grouting according to the present invention, a view showing a ground drilling state, Figure 3 is a cross-sectional view showing an enlarged state in which the drilling bit of Figure 2 is coupled, Figure 4 is It is a perspective view showing a punching bit according to the present invention.

As shown in FIG. 2 , the piston 200 is mounted such that a lowering operation is possible inside the casing 400 to apply an impact to the drill bit 100 , and the piston 200 is raised inside the casing 400 . Alternatively, a piston driving unit 300 for supplying compressed air to operate downward is provided.

A separate inlet pipe for supplying compressed air to the piston driving unit 300 may be provided, and the piston driving unit 300 may be provided with a distributor such that the inflow air is evenly sprayed.

At this time, a chuck 420 to which the drill bit 100 is coupled may be provided at a lower portion of the casing 400 , and a casing shoe 430 surrounding the upper portion of the chuck 420 and the drill bit 100 is provided. can be provided.

At this time, inside the casing 400 , the inner passage 500 formed to be sprayed after the grouting material is supplied to the drill bit 100 , and this inner passage 500 are partitioned, and compressed air flows into the lower portion of the drill bit 100 . An external flow path 600 formed to be injected is provided.

That is, the internal flow path 500 to which the grouting material is supplied and the external flow path 600 to which the compressed air is supplied are partitioned and formed, respectively, but the grouting material is a mixture having various physical properties, and is hardened over time due to its own physical properties As it can be, the piston driving unit 300, the piston 200 and the drill bit 100 are supplied through the independently partitioned internal flow path 500 on the inside so as not to affect the operation, and the compressed air is simply formed on the outside. It is configured to be supplied through the external flow path (600).

In addition, as shown in FIG. 3 , the grouting material supplied through the internal flow path 500 is configured to be sprayed through the drill bit 100 . That is, as shown in FIG. 4 , in the case of the drill bit 100 as a consumable, it is a configuration that needs to be replaced if the drill bit 100 is damaged due to a decrease in durability while the drilling process is repeated, and the grouting material supplied through the internal flow path 500 is such When configured to be sprayed through the drill bit 100 , there is no need to form a channel for supplying the grouting material to the expensive casing 400 , so it is possible to effectively prevent deterioration of the durability of the casing 400 .

Figure 5 is a perspective view showing a drilling device capable of jet grouting according to the present invention, a view showing a grouting material injection state, Figure 6 is a cross-sectional view showing a drilling device capable of jet grouting according to the present invention, the grouting material It is a view showing an injection state, and FIG. 7 is an enlarged cross-sectional view illustrating a state in which the punching bit of FIG. 6 is coupled.

As shown in FIG. 5, the grouting material is injected after the drilling is completed. For this purpose, the nozzle provided in the drill bit 100 while only the casing 400 moves upward while the position of the drill bit 100 is maintained. 110 is configured to be open.

At this time, as shown in FIG. 6 , the aforementioned internal flow path 500 may be formed to extend to the inner circumferential surface of the piston driving unit 300 , the inner circumferential surface of the piston 200 , and the inner circumferential surface of the drill bit 100 .

That is, the piston driving unit 300, the piston 200, and the internal flow path 500 to which the grouting material is supplied to the inside of the drill bit 100 is continuously formed, and the grouting material is configured to be supplied only through this internal flow path 500 will be.

At this time, it is important to configure the grouting material not to leak from the internal flow path 500 . If the grouting material leaks from the internal flow path 500 and moves to the outside of the piston driving unit 300, the piston 200, or the drill bit 100, the grouting material hardens over time. , because the piston 200, or the drill bit 100 may not operate smoothly, as well as close the external flow path 600 to which the compressed air is supplied.

For this purpose, as shown in Figure 6, the inner peripheral surface of the piston driving unit 300, the inner peripheral surface of the piston 200, and the inner peripheral surface of the drill bit 100 at least one inner tube extending along the axial direction (a) A 510 is provided, and the inner flow path 500 may be formed inside the inner tube 510 .

That is, compressed air is supplied through the piston driving unit 300, and through this, the piston 200 moves upward or downward to apply an impact to the drill bit 100, and the drill bit 100 is the shock applied in this way. The perforation proceeds while delivering to the ground (G). In this way, the inner circumferential surface of the piston driving unit 300 and the inner circumferential surface of the piston 200 so that the leakage-preventing state of the internal flow path 500 is maintained even in the process of operating each configuration. And, on the inner circumferential surface of the drill bit 100, the inner tube 510 is extended along the axial direction (a). As shown in FIG. 6 , the inner tube 510 is provided with each inner tube 510 on the inner circumferential surface of the piston driving unit 300 , the inner circumferential surface of the piston 200 , and the inner circumferential surface of the drill bit 100 . In this state, it may be configured to be formed in communication with each other, and at this time, the leakage prevention state can be maintained even during the operation of the piston driving unit 300 , the piston, and the drill bit 100 between the plurality of inner tubes 510 . It is preferred to be constructed.

At this time, the inner tube 510 is configured such that a single inner tube 510 extends while passing through all of the inner circumferential surface of the piston driving unit 300 , the inner circumferential surface of the piston 200 , and the inner circumferential surface of the drill bit 100 . It is possible.

As shown in Figure 3, the drill bit 100 is provided with a nozzle 110 to which the grouting material is sprayed. That is, as described above, since the grouting material supplied through the internal flow path 500 is configured to be sprayed through the nozzle 110 , it is not necessary to form a channel for supplying the grouting material to the expensive casing 400 , so the casing It is possible to effectively prevent deterioration of the durability of 400 .

In addition, the drill bit 100 may be formed with a connection flow path 111 for mutually communicating the internal flow path 500 and the nozzle (110). The connection flow path 111 may be formed to extend outwardly in the radial direction r so that the inner flow path 500 formed on the inner circumferential surface of the drill bit 100 and the nozzle 110 provided on the outer circumferential surface of the drill bit 100 communicate with each other. .

As shown in FIG. 2 , the external flow path 600 is between the piston driving unit 300 and the casing 400 , between the piston 200 and the casing 400 , and the upper part of the drill bit 100 and the casing 400 . ) may be formed to extend between each.

That is, the compressed air supplied through the above-described inlet pipe is uniformly distributed through the distributor provided in the piston driving unit 300 as shown in FIG. 2 , and then the outside between the piston driving unit 300 and the casing 400 . It moves to the piston 200 through the flow path 600 , and the compressed air thus moved moves to a cylinder provided between the piston 200 and the casing 400 . The cylinder is configured such that the piston 200 moves upward or downward using the supplied compressed air.

As shown in FIG. 3 , the compressed air supplied to the cylinder in this way moves to the external flow path 600 extended between the upper part of the drill bit 100 and the casing 400 , and then the inside of the drill bit 100 . It is discharged to the bottom of the drill bit 100 through the. To this end, the inside of the drill bit 100 is an air flow path such that compressed air supplied through the external flow path 600 formed between the upper portion of the drill bit 100 and the casing 400 is sprayed to the lower portion of the drill bit 100 . (120) is formed.

At this time, the air flow path 120 formed in the drill bit 100 is compressed air flowing into one side (left side of FIG. 3 ) of the drill bit 100 to the other side (right side of FIG. 3 ) of the drill bit 100 to the lower side. It may be discharged, and the compressed air introduced to the other side (right side of FIG. 3) of the drill bit 100 may be configured to be discharged to the lower side of one side (left side of FIG. 3) of the drill bit 100. That is, the compressed air discharged through the air passage 120 moves so that the sludge is discharged through the discharge space D formed between the perforated hole H and the outer peripheral surface of the casing 400 . ), the direction of compressed air can be changed smoothly, and the formation of vortices can be minimized, and through this, the sludge can be smoothly discharged.

As shown in FIG. 3 , the casing 400 is disposed to surround the outside of the nozzle 110 to prevent the nozzle 110 provided in the drill bit 100 from being exposed to the outside when the ground (G) is drilled. And, through this, it is possible to prevent the nozzle 110 from being damaged in the ground (G) drilling process.

In addition, as shown in FIG. 7 , when the grouting material is sprayed after drilling the ground (G), the casing 400 is configured to move upward a certain distance (d) so that these nozzles 110 are exposed to the outside, so that the grouting material is high pressure. By spraying, effective jet grouting is possible.

At this time, the casing 400 and the drill bit 100 may be slidably mounted while moving relative to each other so that the position of the drill bit 100 is constantly maintained in the process of moving the casing 400 upward by a certain distance d. have.

That is, as shown in Fig. 3, when the ground (G) is drilled, the casing 400 is moved downward to prevent exposure of the nozzle 110 to the outside and surrounds the outside of the nozzle 110, and the ground G ) When the drilling is completed, only the casing 400 moves upward a certain distance (d) while the position of the drill bit 100 is fixed. 7, as the casing 400 moves upward, the chuck 420 and the casing shoe 430 fixed to the casing 400 also move upward, and in this process, the chuck 420 is a drill bit By being configured to slide with respect to (100), the position of the drill bit 100 is fixed and the nozzle 110 is exposed to the outside.

As described above, the drill bit 100 needs to maintain a constant position even when the casing 400 moves upward a certain distance d so that the nozzle 110 is exposed to the outside, and for this purpose, the drill bit ( If the weight of 100 is configured to be greater than the friction force formed between the drill bit 100 and the chuck 420 , even if the casing 400 moves upward, the position of the drill bit 100 can be constantly maintained.

In this way, when the jet grouting operation of spraying the grouting material at high pressure in a state in which the casing 400 moves upward by a certain distance (d) ends, the drilling device is withdrawn to the outside of the ground (G). In the process of taking out, the jet grouting operation may be continuously performed. To this end, the drilling device must be drawn out to the outside of the ground (G) while the nozzle 110 of the drill bit 100 is maintained in an open state, and for this, the upper end of the drill bit 100 is radially r outward. An extended protrusion 130 is formed, and on the inner circumferential surface of the casing 400, a locking portion 410 that is caught by the protrusion 130 when the casing 400 moves upward is formed in the radial direction (r) inside, and the ground is perforated. The protrusion 130 and the locking part 410 may be spaced apart from each other by a predetermined distance d.

That is, when the ground (G) is drilled, as shown in FIG. 3, the protrusion 130 and the locking part 410 are maintained at a predetermined distance (d) apart, and the grouting material is injected after the ground (G) drilling. For this purpose, as shown in FIG. 7 , jet grouting is performed by injecting a high-pressure grouting material in a state in which the nozzle 110 is exposed to the outside while the casing 400 moves upward a certain distance d. ) moves upward by a certain distance (d), the protrusion 130 and the locking part 410 come into contact with each other, and when the casing 400 is further moved upward in this state, the protrusion 130 becomes the locking part 410 ), the drill bit 100 also moves upward as it moves upward in the state caught by the ), and as the drill bit 100 moves upward in this way, the high-pressure grouting material is continuously sprayed to drill the hole along the axial direction (a). It becomes possible to jet grout evenly inside the hole H.

As shown in FIG. 2 , the inner tube 510 is disposed on the inside of the piston 200 so as to communicate with the first tube 511 and the first tube 511 disposed on the inside of the drill bit 100 . It may include a second tube 512 and a third tube 513 disposed inside the piston driving unit 300 so as to communicate with the second tube 512 .

At this time, the first tube 511 is inserted and fixed inside the drill bit 100 , and the third tube 513 is inserted and fixed inside the piston driving unit 300 , and the second In the tube 512, one end of the second tube 512 is inserted into the third tube 513, and the other end of the second tube 512 is disposed with the first tube 511 inserted therein. That is, both ends of the second tube 512 are respectively connected to the first tube 511 and the third tube 513, and are spaced apart from the inner peripheral surface of the piston 200 by a predetermined distance in the radial direction (r). will keep This is because stable sealing is possible by preventing external force from being applied from the piston 200 when the piston 200 moves upward or downward.

In addition, it is preferable that a seal preventing leakage is formed between each tube so that the high-pressure grouting material does not leak from the inner tube 510 during jet grouting.

At this time, the seal between each of these tubes needs to be stably formed not only when drilling, but also when grouting material is injected. That is, as shown in FIG. 2, it is easy to maintain the sealing because relative movement is not formed between each of these tubes during perforation, but as shown in FIG. 6, when the casing 400 moves upward The third tube 513 and the second tube 512 inserted and fixed thereto move upward together with the piston driving unit 300 , while the drill bit 100 and the position of the first tube 511 inserted and fixed thereto Since is fixed, relative movement occurs between the first tube 511 and the second tube 512, so it is important that the sealing is stably maintained even in this process.

To this end, the first tube 511 is provided with a sealing portion 511a for sealing between the first tube 511 and the second tube 512, and the sealing portion 511a is provided with a second It is configured to be disposed upward by the sealing distance (s) from the lower end of the tube (512).

That is, as shown in FIG. 3 , when the ground (G) is drilled, a sealing portion (511a) is provided on the outer peripheral surface of the first tube (511) to seal between the first tube (511) and the second tube (512). This is formed, this sealing portion (511a) is disposed upward by a sealing distance (s) from the lower end of the second tube (512), as shown in Figure 7, the casing 400 for jet grouting a certain distance ( d) between the first tube 511 and the second tube 512 through the sealing portion 511a even when relative movement between the first tube 511 and the second tube 512 occurs as it moves upward It is important that the sealing is maintained, and for this purpose, the sealing distance (s) formed between the first tube (511) and the second tube (512) is formed to be greater than a certain distance (d) through which the casing 400 moves upward. It is preferable to be

As described above, the drilling device capable of jet grouting of the present invention can supply high-pressure air and high-pressure grouting material for operating the piston 200 through each partitioned flow path inside the casing 400, so the casing 400 It is possible to reduce the construction cost by effectively preventing the deterioration of durability.

In addition, since the nozzle 110 for injection of the grouting material is not exposed to the outside during the drilling process, and the nozzle 110 is exposed to the outside only during the process of injecting the high-pressure grouting material, the high-pressure injection of the grouting material for jet grouting is can proceed smoothly.

Although one embodiment of the present invention has been described above, the spirit of the present invention is not limited to the embodiments presented herein, and those skilled in the art who understand the spirit of the present invention can add components, Other embodiments may be easily proposed by changes, deletions, additions, etc., but these will also fall within the scope of the present invention.

100: drill bit 110: nozzle
111: connecting flow path 120: air flow path
130: protrusion 200: piston
300: piston driving unit 400: casing
410: locking part 420: chuck
430: casing shoe 500: inner flow
510: inner tube 511: first tube
511a: sealing part 512: second tube
513: third tube 600: external flow path
a : axial direction r : radial direction
d: a certain distance the casing moves upwards
s : sealing distance D : exhaust space
G : Ground H : Perforated hole

Claims (12)

delete delete delete delete delete delete delete delete delete delete drill bits for drilling the ground;
a piston mounted so as to be capable of descending to apply an impact to the drill bit;
a piston driving unit for supplying compressed air so that the piston moves upward or downward;
a casing formed to surround the upper portion of the drill bit, the piston, and the piston driving unit;
an internal flow path formed to be sprayed after the grouting material is supplied to the drill bit; and
an external flow path formed to be partitioned from the internal flow path and configured to spray compressed air to a lower portion of the drill bit;
includes,
At least one inner tube extending along the axial direction is provided on the inner circumferential surface of the piston driving unit, the inner circumferential surface of the piston, and the inner circumferential surface of the drill bit,
The inner flow path is formed inside the inner tube,
The drill bit is provided with a nozzle to which the grouting material is sprayed,
The casing is disposed to surround the outside of the nozzle to prevent the nozzle from being exposed to the outside when drilling the ground,
When the grouting material is sprayed after the ground drilling, the casing moves upward a certain distance so that the nozzle is exposed to the outside,
The inner tube includes a first tube disposed inside the drill bit, a second tube disposed inside the piston to communicate with the first tube, and disposed inside the piston driving unit to communicate with the second tube. A drilling device capable of jet grouting comprising a third tube being 12. The method of claim 11,
The first tube is provided with a sealing portion for sealing between the first tube and the second tube,
The sealing part is a drilling device capable of jet grouting that is disposed upward by a sealing distance from the lower end of the second tube when drilling the ground.

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