Three-blade drill bit

Abstract

The utility model discloses a three-blade drill bit, which aims at drilling a hole downwards, directly utilizing a high-pressure spray head to expand the body after the designed depth is reached, and not needing to lift and replace the drill bit, and adopts the technical scheme that the three-blade drill bit comprises a rod body, and a drill blade is arranged at one end of the rod body; the number of the drill blades is three, the drill blades are evenly distributed around the axis of the rod body in the circumferential direction, a cavity is formed in the rod body, the end, away from the drill blades, of the cavity is an open end, a pipe body used for being connected with an external grouting pipe is arranged in the cavity, at least one mounting hole is formed in the peripheral wall of the pipe body, and the mounting hole is communicated with the cavity. Mounting holes are formed in the pipe body, hollow holes in one-to-one correspondence with the mounting holes are formed in the rod body, high-pressure spray heads are assembled in the mounting holes, and the distance between the end, away from the pipe body, of each high-pressure spray head and the axis of the rod body is smaller than or equal to the radius of the rod body.

Description

Technical Field

[0001] The utility model belongs to the field of exploration technology, and more specifically relates to a three-blade drill bit. Background Art

[0002] At present, high-pressure nozzle drill bits are generally used for hole expansion and cannot drill directly into the borehole. Based on this, the construction method of expanding the capsule expansion anchor in the bearing layer of the anchoring section is mainly divided into two steps. First, a conventional three-blade drill bit is used to drill to the designed depth, and then the drill bit is lifted and replaced with a high-pressure nozzle drill bit for expansion. The entire construction process requires repeated replacement of the drill bit, which affects the drilling efficiency and takes a long time to construct. Utility Model Content

[0003] The main purpose of the utility model is to provide a three-blade drill bit, which is designed to be able to drill into a borehole downwards, and after reaching the designed depth, the body can be directly expanded by a high-pressure nozzle without lifting and replacing the drill bit.

[0004] According to the first aspect of the utility model, a three-blade drill bit is provided, comprising a rod body, one end of the rod body is provided with a drilling blade, the drilling blades are three in number and are evenly distributed circumferentially around the axis of the rod body, the rod body has a cavity, the end of the cavity away from the drilling blade is an open end, a tube body for connecting an external grouting pipe is provided in the cavity, at least one mounting hole is provided on the outer peripheral wall of the tube body, the rod body is provided with hollow holes corresponding to the mounting holes one by one, a high-pressure nozzle is mounted in the mounting hole, and the spacing between the end of the high-pressure nozzle away from the tube body and the axis of the rod body is less than or equal to the radius of the rod body.

[0005] The above-mentioned three-leaf drill bit also includes a cover body adapted to the hollow hole, and a recessed portion is provided on the side of the cover body facing away from the tube body. The high-pressure nozzle passes through the bottom of the recessed portion. The high-pressure nozzle is fixedly connected to the cover body, and a gap is formed between the inner circumferential wall of the recessed portion and the outer wall of the high-pressure nozzle.

[0006] In the above-mentioned three-leaf drill, the outer wall of the high-pressure nozzle has a wrench part for the external sleeve to be mounted, and the wrench part is located on the side of the recessed part facing away from the tube body. A gap is formed between the inner circumferential wall of the recessed part and the outer wall of the wrench part, and the gap can be used for the external sleeve to be inserted.

[0007] In the above-mentioned three-leaf drill bit, there is a gap of 2 to 4 mm between the outer wall of the cover body and the inner wall of the hollow hole.

[0008] In the above-mentioned three-blade drill, the high-pressure nozzle is fixed in the mounting hole by threaded connection.

[0009] In the above-mentioned three-blade drill bit, two mounting holes are evenly distributed circumferentially on the tube body.

[0010] In the above-mentioned three-blade drill bit, the distance between the liquid inlet of the high-pressure nozzle and the end of the tube body close to the drill blades is 1 to 10 mm.

[0011] One of the above technical solutions of the utility model has at least one of the following advantages or beneficial effects:

[0012] The utility model modifies the existing three-leaf drill bit, opens a mounting hole on the pipe body, installs a high-pressure nozzle, and provides a hollow hole on the rod body to expose the high-pressure nozzle. When in use, the three-leaf drill bit can drill downward into the borehole. After reaching the designed depth, the external grouting pipe is filled with slurry, and the slurry enters the pipe body and is then sprayed out from the high-pressure nozzle to achieve body expansion. Based on this, there is no need to lift the drill bit for replacement, the drilling efficiency is higher, and the construction period is shortened.

[0013] Moreover, the distance between the end of the high-pressure nozzle away from the tube body and the axis of the rod body is less than or equal to the radius of the rod body, so that the high-pressure nozzle will not protrude from the rod body, thereby avoiding damage to the high-pressure nozzle during the drilling process. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The utility model is further described below in conjunction with the accompanying drawings and embodiments;

[0015] Figure 1 It is a structural schematic diagram of the first embodiment of the utility model;

[0016] Figure 2 It is a structural exploded view of the first embodiment of the utility model;

[0017] Figure 3 It is a structural sectional view of the first embodiment of the utility model.

[0018] Among them, the reference numerals of each figure are:

[0019] 1. Rod body; 11. Cavity; 12. Hollow hole; 2. Drill blade; 3. Tube body; 31. Mounting hole; 4. High-pressure nozzle; 41. Cover body; 42. Wrench part; 43. Gap. DETAILED DESCRIPTION

[0020] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions from beginning to end. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0021] The following disclosure provides many different embodiments or examples for implementing different solutions of the present invention.

[0022] Reference Figures 1 to 3 As shown, in one embodiment of the utility model, a three-blade drill bit includes a rod body 1, one end of the rod body 1 is provided with a drill blade 2, the drill blade 2 is 3 and is evenly distributed around the axis of the rod body 1, the rod body 1 has a cavity 11, the end of the cavity 11 away from the drill blade 2 is an open end, the cavity 11 is provided with a pipe body 3 for connecting an external grouting pipe, the outer peripheral wall of the pipe body 3 is provided with at least one mounting hole 31, the rod body 1 is provided with a hollow hole 12 corresponding to the mounting hole 31, the mounting hole 31 is equipped with a high-pressure nozzle 4, and the slurry sprayed by the high-pressure nozzle 4 can pass through the hollow hole 12;

[0023] When in use, the rod body 1 is connected to the external drill rod, and the grouting pipe in the external drill rod will connect to the pipe body 3. Relying on the three drill blades 2, the drill bit can drill downward into the borehole. After reaching the designed depth, the external grouting pipe is filled with slurry, and the slurry enters the pipe body 3 and is then sprayed out from the high-pressure nozzle 4 to achieve body expansion. Based on this, there is no need to lift the drill bit for replacement, the drilling efficiency is higher, and the construction period is shortened;

[0024] Moreover, the distance between the end of the high-pressure nozzle 4 away from the tube body 3 and the axis of the rod body 1 is less than or equal to the radius of the rod body 1, so that the high-pressure nozzle 4 will not protrude from the rod body 1, avoiding damage to the high-pressure nozzle 4 during the drilling process.

[0025] In this embodiment, the high-pressure nozzle 4 is fixed in the mounting hole 31 by threaded connection.

[0026] In this embodiment, the distance between the liquid inlet of the high-pressure nozzle 4 and the end of the tube body 3 close to the drill blade 2 is 1 to 10 mm. In this way, after the liquid supply is interrupted, the remaining slurry inside the tube body 3 can be sprayed out through the high-pressure nozzle 4 by relying on the residual pressure in the tube body 3. Slurry will hardly accumulate in the tube body 3, thereby preventing the slurry from solidifying in the tube body 3 and clogging the high-pressure nozzle 4.

[0027] In practice, once the high-pressure nozzle 4 is damaged or blocked, it needs to be disassembled, replaced or repaired. If the gap between the hollow hole 12 and the high-pressure nozzle 4 is large, it is easy to get stuck with stones, making it difficult to disassemble the high-pressure nozzle 4. Therefore, the high-pressure nozzle 4 needs to be optimized in design.

[0028] A cover body 41 adapted to the hollow hole 12 is designed, a recessed portion is provided on the side of the cover body 41 facing away from the tube body 3, a high-pressure nozzle 4 passes through the bottom of the recessed portion, the high-pressure nozzle 4 is fixedly connected to the cover body 41, and an outer wall of the high-pressure nozzle 4 has a wrench portion 42 for an external sleeve to be sleeved, the wrench portion 42 is located on the side of the recessed portion facing away from the tube body 3, a gap 43 is formed between the inner circumferential wall of the recessed portion and the outer wall of the wrench portion 42, and the gap 43 can be inserted into the external sleeve;

[0029] When in use, the outer sleeve is inserted into the gap 43 and can be put on the wrench part 42 of the high-pressure nozzle 4, so as to rotate the cover body 41 and the high-pressure nozzle 4 and disassemble and assemble the high-pressure nozzle 4; and the gap between the outer wall of the cover body 41 and the inner wall of the hollow hole 12 is small, so stones will not be stuck.

[0030] Preferably, there is a gap of 2 to 4 mm between the outer wall of the cover body 41 and the inner wall of the hollow hole 12, which does not affect the rotation of the cover body 41 and can prevent stones from getting stuck.

[0031] In this embodiment, the cross-sectional outer contour of the wrench portion 42 in a direction perpendicular to the axial direction of the high-pressure nozzle 4 is hexagonal.

[0032] In this embodiment, the cover body 41 and the high-pressure nozzle 4 are fixed together by welding.

[0033] In this embodiment, two mounting holes 31 are evenly distributed on the circumference of the tube body 3 , and two high-pressure nozzles 4 can be installed at the same time.

[0034] In some other embodiments, one mounting hole 31 may be used to mount the high-pressure nozzle 4, and another mounting hole 31 may be used to mount a plug.

[0035] Although the embodiments of the present invention have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A three-blade drill bit, It is characterized in that It includes a rod body, one end of which is provided with a drilling blade, and the number of the drilling blades is three and evenly distributed around the axis of the rod body. The rod body has a cavity, and the end of the cavity away from the drilling blade is an open end. A tube body for connecting an external grouting pipe is provided in the cavity, and at least one mounting hole is provided on the outer peripheral wall of the tube body. The rod body is provided with hollow holes corresponding to the mounting holes one by one, and a high-pressure nozzle is installed in the mounting hole. The distance between the end of the high-pressure nozzle away from the tube body and the axis of the rod body is less than or equal to the radius of the rod body.

2. The three-blade drill bit according to claim 1, It is characterized in that It also includes a cover body adapted to the hollow hole, a recessed portion is provided on the side of the cover body facing away from the tube body, the high-pressure nozzle passes through the bottom of the recessed portion, the high-pressure nozzle is fixedly connected to the cover body, and a gap is formed between the inner circumferential wall of the recessed portion and the outer wall of the high-pressure nozzle.

3. The three-blade drill bit according to claim 2, It is characterized in that The outer wall of the high-pressure nozzle has a wrench portion for the external sleeve to be mounted, and the wrench portion is located on the side of the recessed portion facing away from the tube body. A gap is formed between the inner circumferential wall of the recessed portion and the outer wall of the wrench portion, and the gap can be used for the external sleeve to be inserted.

4. The three-blade drill bit according to claim 2, It is characterized in that There is a gap of 2 to 4 mm between the outer wall of the cover and the inner wall of the hollow hole.

5. The three-blade drill bit according to claim 1, It is characterized in that The high-pressure nozzle is fixed in the mounting hole by threaded connection.

6. The three-blade drill bit according to claim 1, It is characterized in that Two mounting holes are evenly distributed on the circumference of the tube body.

7. The three-blade drill bit according to claim 1, It is characterized in that The distance between the liquid inlet of the high-pressure nozzle and the end of the tube body close to the drill blade is 1 to 10 mm.

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