High-pressure jet grouting drill bit for gravel-cobble stratum

Abstract

The utility model relates to a high-pressure jet grouting drill bit for a gravel-cobble stratum, and belongs to the technical field of high-pressure jet grouting pile construction.The high-pressure jet grouting drill bit comprises a drill rod connecting base, the drill rod connecting base is of a hollow structure, a first tooth holder is coaxially fixed to the drill rod connecting base, a slurry outlet is formed in the first tooth holder, and part of the slurry outlet is communicated with the interior of the drill rod connecting base; the slurry outlet hole partially extends out of the drill rod connecting base, at least two second tooth holders are fixed to the circumferential face of the drill rod connecting base, the circumferential faces of the second tooth holders are connected with the circumferential face of the drill rod connecting base, cutting teeth are installed on the first tooth holders and the second tooth holders, and the central axes of the cutting teeth of the first tooth holders and the central axes of the cutting teeth of the second tooth holders form staggered angles. And the central axis of the cutting tooth of the first tooth holder and the central axis of the cutting tooth of the second tooth holder are in different planes. The drill bit has the advantages that the abrasion resistance of the drill bit is improved, abrasion of the cutting teeth is reduced, the service life of the drill bit is prolonged, and drilling can be stably conducted in a gravel-cobble stratum.

Description

Technical Field

[0001] This application relates to the technical field of high-pressure jet grouting pile construction, and particularly relates to a high-pressure jet grouting bit for cobble strata. Background Technique

[0002] High-pressure jet grouting drilling is an advanced foundation treatment technology, usually used in projects such as strengthening soft foundations, controlling groundwater seepage, and preventing soil slides. This technology cuts and mixes soil layers by high-pressure jetting of slurry or cement slurry and combining with rotary drilling, thereby forming a soil-cement mixture or solidified body with high strength and stability.

[0003] A common high-pressure jet grouting drill bit is installed at the end of the drill pipe and is also provided with nozzles. When drilling, slurry or cement slurry is conveyed into the drill pipe through a pumping system. During the drilling process, the nozzles spray the slurry into the soil layer at a very high pressure (usually between 10 and 40 MPa) at a high speed, and combined with the rotary motion of the drill pipe, the soil layer is broken, cut, and mixed.

[0004] However, when encountering cobble strata, such as cemented sand layers or particularly dense cobble layers, ordinary drill bits cannot effectively drill holes. Usually, there is no footage or the footage speed is slow (0.2 - 0.5 m / min), and the drill bit and drill pipe are severely worn. There may be a situation where the drill bit and drill pipe need to be scrapped after completing one drill hole.

[0005] Therefore, to solve the above problems, the utility model patent with the publication number CN216341922U discloses a triple high-pressure jet grouting pile drill bit. By using the strength of the picks and the cooperation of multiple picks, small-sized cobbles and cemented sand can be cut, and large-sized cobbles and cemented sand can be extruded into the soil layer of the hole wall to complete the cutting smoothly.

[0006] However, there are still problems in the design of the above triple high-pressure jet grouting pile drill bit. The arrangement of multiple picks in the above drill bit makes the central axis of each pick located on the same vertical horizontal plane. When the picks on both sides rotate to extrude and cut the cobbles, the tangential force on the pick is perpendicular to the central axis of the pick, resulting in local stress concentration and increasing the risk of pick wear and fracture. Utility Model Content

[0007] In order to improve the wear resistance of the drill bit, reduce the wear of the picks, extend the service life of the drill bit, and be able to stably drill holes in cobble strata, this application provides a high-pressure jet grouting drill bit for cobble strata.

[0008] The high-pressure jet grouting drill bit for cobble strata provided by this application adopts the following technical solutions:

[0009] A high-pressure jet grouting bit for cobble strata, comprising a drill pipe connection base. The drill pipe connection base is of a hollow structure. A first tooth seat is coaxially fixed on the drill pipe connection base. A slurry outlet hole is formed in the first tooth seat. Part of the slurry outlet hole communicates with the inside of the drill pipe connection base, and part of the slurry outlet hole extends out of the drill pipe connection base. At least two second tooth seats are fixed on the circumferential surface of the drill pipe connection base. The circumferential surface of the second tooth seat is connected to the circumferential surface of the drill pipe connection base. Picks are installed on both the first tooth seat and the second tooth seat. The central axis of the pick on the first tooth seat and the central axis of the pick on the second tooth seat have a staggered angle, and the central axis of the pick on the first tooth seat and the central axis of the pick on the second tooth seat are skew lines.

[0010] By adopting the above technical solution, when high-pressure jet grouting drilling is carried out on cobble strata (cemented sand strata or particularly dense cobble strata), due to the high strength of the picks, it is easy to squeeze or cut and crush cobbles or stones during rotation, and it is not easily damaged. Moreover, this design makes the rotation diameter of the picks of the bit larger than the diameters of the drill pipe and the drill pipe connection base, reducing the wear of the drill pipe and the drill pipe connection base and extending the service life of the drill pipe.

[0011] Furthermore, due to the design of the staggered angle, when the picks on both sides rotate to squeeze and cut the cobbles, the tangential force received by the picks can be decomposed into a component perpendicular to the whole body of the pick and a component along the central axis of the pick. Therefore, the force in the direction perpendicular to the whole body of the pick is reduced, the wear of the pick is reduced, and the possibility of the pick breaking is lowered, thereby extending the service life of the pick and further increasing the service life of the bit.

[0012] Optionally, the tip of the pick on the second tooth seat has a deviation angle deviating away from the central axis of the drill pipe connection base.

[0013] By adopting the above technical solution, the design of the deviation angle can make the tip of the pick contact the hole wall first during the drilling process. The strength of the tip part of the pick is much higher than that of the whole body of the pick, which is not only beneficial to increasing the drilling hole diameter, but also reducing the friction between the whole body of the pick and the soil body, and further reducing the wear of the pick.

[0014] Optionally, the staggered angle between the central axis of the pick on the first tooth seat and the central axis of the pick on the second tooth seat is 45°, and the central axis of the pick on the second tooth seat deflects clockwise;

[0015] The deviation angle of the tip of the pick on the second tooth seat is 5°.

[0016] Optionally, the horizontal plane where the tip of the pick on the second tooth seat is located is farther away from the drill pipe connection base than the horizontal plane where the installation end of the pick on the first tooth seat is located.

[0017] By adopting the above technical solution, during the drilling process, the picks of the first tooth base first drill holes. After the picks of the first tooth base penetrate into the soil body, the picks of the second tooth base can cooperate with the picks of the first tooth base to drill holes, thereby reducing the wear on the whole body of the picks of the first tooth base and improving the service life of the drill bit.

[0018] Optionally, a guide plate is connected to the bottoms of the two second tooth bases. One side of the guide plate is fixed to the drill pipe connection base, and the side of the guide plate away from the drill pipe connection base is provided with an arc-shaped guide surface. The guide plate is inclined, and the end of the guide plate connected to the second tooth base is closer to the first tooth base than the other end of the guide plate.

[0019] By adopting the above technical solution, the guide plate not only strengthens the connection between the second tooth base and the drill pipe connection base, but also the design of the guide surface can squeeze the soil during the drilling process and push the soil towards the orifice, reducing the resistance of the drill pipe to drill holes, and can also play a role in protecting the drill pipe connection base and reducing the wear on the drill pipe connection base.

[0020] Optionally, a protective plate is connected to the circumferential surface of the second tooth base. One end of the protective plate is fixed to the circumferential surface of the second tooth base, and the other end of the protective plate is fixed to the drill pipe connection base. The protective plate is arranged on one side of the second tooth base in the rotational direction relative to the drill pipe connection base.

[0021] By adopting the above technical solution, the protective plate further strengthens the connection between the second tooth base and the drill pipe connection base, and during the drilling process, the protective plate blocks in front of the second tooth base and contacts the soil body, playing a role in protecting the second tooth base and reducing the wear on the second tooth base.

[0022] Optionally, a filling plate is fixed on the drill pipe connection base. The filling plate fills the space between the protective plate and the drill pipe connection base and the space between the second tooth base and the drill pipe connection seat. The filling plate is connected to the second tooth base and the protective plate.

[0023] By adopting the above technical solution, the filling plate further strengthens the connection between the second tooth base and the protective plate and the drill pipe connection base, making the whole drill bit more stable during the drilling process.

[0024] Optionally, a plurality of wear-resistant points are arranged on the circumferential surface of the pick near its tip.

[0025] By adopting the above technical solution, the design of the wear-resistant points is beneficial to reducing the wear on the whole body of the pick, and the wear-resistant points have high strength and are easier to squeeze or crush pebbles.

[0026] Optionally, the first tooth base and the second tooth base are connected by the connecting plate.

[0027] In summary, the present application includes at least one of the following beneficial technical effects:

[0028] 1. When high-pressure jet grouting drilling is carried out on cobble strata (cemented sand strata or particularly dense cobble strata), due to the high strength of the picks, it is easy to squeeze or cut and crush cobbles or stones during rotation, which speeds up the hole-forming speed of the high-pressure jet grouting cut-off wall or pile, shortens the hole-forming time, greatly reduces the slurry generated during the hole-forming process, and the picks cooperate with the first tooth seat and the second tooth seat, with flexible disassembly and simple replacement, improving the construction efficiency;

[0029] 2. This design makes the rotation diameter of the drill bit picks larger than the diameters of the drill pipe and the drill pipe connection base, reducing the wear of the drill pipe and the drill pipe connection base and extending the service life of the drill pipe;

[0030] 3. Due to the design of the staggered angle, when the picks on both sides rotate to squeeze and cut the cobbles, the tangential force received by the picks can be decomposed into a component perpendicular to the whole body of the pick and a component along the central axis of the pick. Therefore, the force in the direction perpendicular to the whole body of the pick is reduced, the wear of the pick is reduced, and the possibility of pick fracture is lowered, thereby extending the service life of the pick and further extending the service life of the drill bit;

[0031] 4. The design of the deviation angle enables the tip of the pick to contact the hole wall first during the drilling process. The strength of the tip part of the pick is much higher than that of the whole body of the pick, which not only helps to increase the drilling hole diameter, but also reduces the friction between the whole body of the pick and the soil, further reducing the wear of the pick;

[0032] 5. The guide plate not only strengthens the connection between the second tooth seat and the drill pipe connection base, but also the design of the guide surface can squeeze the soil and push the soil towards the hole opening direction during the drilling process, reducing the resistance of the drill pipe during drilling, and can also play a role in protecting the drill pipe connection base, reducing the wear of the drill pipe connection base;

[0033] 6. The protection plate further strengthens the connection between the second tooth seat and the drill pipe connection base, and during the drilling process, the protection plate blocks in front of the second tooth seat and contacts the soil, playing a role in protecting the second tooth seat and reducing the wear of the second tooth seat. Description of the Drawings

[0034] Figure 1 is the overall structural schematic diagram of the embodiment of the present application.

[0035] Figure 2 is the structural schematic diagram of the embodiment of the present application for showing the guide plate.

[0036] Description of reference numerals: 1. Drill pipe connection base; 2. First tooth seat; 21. Slurry outlet hole; 3. Second tooth seat; 4. Pick; 41. Wear-resistant point; 5. Connection plate; 6. Guide plate; 61. Arc-shaped guide surface; 7. Protection plate; 8. Filling plate. Detailed implementation mode

[0037] The following further elaborates on this application Figure 1-2 in conjunction with the accompanying drawings.

[0038] The embodiment of this application discloses a high-pressure jet grouting bit for cobble strata.

[0039] As Figure 1 and Figure 2 , the high-pressure jet grouting bit for cobble strata includes a drill pipe connection base 1. The drill pipe connection base 1 is made of Q355 steel. The drill pipe connection base 1 is of a hollow structure. One end of the drill pipe connection base 1 connected to the drill pipe is a square tubular shape, and the end of the drill pipe connection base 1 away from the drill pipe is a circular tubular shape. The whole body of the drill pipe connection base 1 is an annular convex part, and the outer diameter of the annular convex part is greater than the outer diameter of the drill pipe connection base 1;

[0040] A first tooth seat 2 is inserted at the end of the drill pipe connection base 1 away from the drill pipe. The whole body of the first tooth seat 2 is welded to the inner wall of the drill pipe connection base 1. The whole body of the first tooth seat 2 is provided with slurry outlet holes 21. A part of the slurry outlet holes 21 is located inside the drill pipe connection base 1 and communicates with its internal space, and the other part of the slurry outlet holes 21 extends out of the drill pipe connection base 1. Picks 4 are installed on the first tooth seat 2; the first tooth seat 2 and the picks 4 on the first tooth seat 2 are coaxial with the drill pipe connection base 1;

[0041] The whole body of the drill pipe connection base 1 is welded with a second tooth seat 3. The peripheral surface of the second tooth seat 3 is welded to the peripheral surface of the drill pipe connection base 1, and full welding is used. The tail of the second tooth seat 3 and the axis between the first tooth seat 2 and the drill pipe connection base 1 are welded by surfacing. Picks 4 are also installed on the second tooth seat 3, and the second tooth seat 3 and the picks 4 on the second tooth seat 3 are coaxial;

[0042] The number of the second tooth seats 3 is two. The two second tooth seats 3 are symmetrically arranged about the central axis of the drill pipe connection base 1. The central axes of the second tooth seat 3 and its corresponding picks 4 are skew with the central axes of the first tooth seat 2 and its corresponding picks 4, and the second tooth seat 3 and its corresponding picks 4 are deflected clockwise, so that the central axes of the second tooth seat 3 and its corresponding picks 4 and the central axes of the first tooth seat 2 and its corresponding picks 4 form a stagger angle of 45°. At the same time, the picks 4 on the second tooth seat 3 deviate in the direction away from the central axis of the drill pipe connection base 1, forming a deviation angle of 5°. The horizontal plane where the tips of the picks 4 on the second tooth seat 3 are located is farther from the drill pipe connection base 1 than the horizontal plane where the installation ends of the picks 4 on the first tooth seat 2 are located.

[0043] The tip of the pick 4 is an alloy head. Ten evenly distributed wear-resistant points 41 are surfacing welded around the pick 4 near its tip. The body of the pick 4 is made of high-quality high-chromium alloy steel, and the commonly used 3050 alloy pick 4 in the market is adopted. The first tooth seat 2 and the second tooth seat 3 are alloy circular seats.

[0044] The first tooth seat 2 and the second tooth seat 3 are connected by a connecting plate 5. One end of the connecting plate 5 is welded to the circumferential surface of the first tooth seat 2, and the other end of the connecting plate 5 is welded to the circumferential surface of the second tooth seat 3.

[0045] A guide plate 6 is welded to one end of the second tooth seat 3 away from its corresponding pick 4. The guide plate 6 is an arc-shaped plate. One side of the guide plate 6 is fully welded to the circumferential surface of the drill pipe connection base 1. The other side of the guide plate 6 is an arc-shaped guide surface 61. The guide plate 6 is inclined. The arc direction of the guide plate 6 towards the second tooth seat 3 is the same as the rotation direction of the drill pipe.

[0046] A protective plate 7 is welded to the circumferential surface of the second tooth seat 3. One end of the protective plate 7 is welded to the circumferential surface of the second tooth seat 3, and the welding part of the protective plate 7 and the second tooth seat 3 is close to the end where the second tooth seat 3 is installed with the pick 4. The other end of the protective plate 7 is welded to the annular protrusion of the drill pipe connection base 1. The protective plate 7 is arranged on one side of the second tooth seat 3 in the relative rotation direction of the drill pipe connection base 1;

[0047] A filling plate 8 is welded to the drill pipe connection base 1. The filling plate 8 fills the space between the protective plate 7 and the drill pipe connection base 1 and the space between the second tooth seat 3 and the drill pipe connection base 1. The filling plate 8 is welded to the second tooth seat 3 and the protective plate 7.

[0048] The guide plate 6, the protective plate 7 and the connecting plate 5 are all made of spring steel plates. The weld height of all welded parts is greater than 10 mm.

[0049] When high-pressure jet grouting drilling is carried out on cobblestone formations (cemented sand layers or particularly dense cobblestone layers), due to the high strength of the pick 4, it is easy to squeeze or cut and crush cobblestones or stones during the rotation process and is not easily damaged;

[0050] Since the rotation diameter of the drill bit pick 4 is larger than the diameters of the drill pipe and the drill pipe connection base 1, the contact between the drill pipe and the drill pipe connection base 1 and the soil is reduced;

[0051] Due to the design of the staggered angle, when the picks 4 on both sides rotate to squeeze and cut the cobblestones, the tangential force received by the pick 4 can be decomposed into a component force perpendicular to the whole body of the pick 4 and a component force along the central axis of the pick 4. Therefore, the force in the direction perpendicular to the whole body of the pick 4 is reduced, the wear of the pick 4 is reduced, and the possibility of the pick 4 breaking is lowered;

[0052] Moreover, the design of the deviation angle can make the tip of the pick 4 contact the hole wall first during the drilling process. The strength of the tip part of the pick 4 is much higher than that of the whole body of the pick 4, which not only helps to increase the drilling hole diameter, but also reduces the friction between the whole body of the pick 4 and the soil body;

[0053] Meanwhile, the design of the wear-resistant point 41 helps to reduce the wear of the whole body of the pick 4, and the wear-resistant point 41 has high strength and is more likely to squeeze or crush pebbles;

[0054] Furthermore, the pick 4 of the first tooth seat 2 drills the hole first. When the pick 4 of the first tooth seat 2 drills into the soil body, the pick 4 of the second tooth seat 3 can cooperate with the pick 4 of the first tooth seat 2 to drill the hole, thereby further reducing the wear of the whole body of the pick 4 of the first tooth seat 2;

[0055] During the drilling process, the protective plate 7 blocks in front of the second tooth seat 3 and contacts the soil body, which has the function of protecting the second tooth seat 3 and reducing the wear of the second tooth seat 3;

[0056] Meanwhile, the design of the guiding surface can squeeze the soil and push the soil towards the hole opening direction during the drilling process, reducing the resistance of the drill rod to drill the hole, and can also play a role in protecting the drill rod connection base 1;

[0057] The guiding plate 6, the protective plate 7, the connecting plate 5 and the filling plate 8 all firmly fix the first tooth seat 2 and the second tooth seat 3 on the drill rod connection base 1, making the whole drill bit more stable during the drilling process.

[0058] In summary, the drill bit improves the wear resistance of the drill bit, reduces the wear of the pick 4, prolongs the service life of the drill bit, and can stably drill in the cobble and gravel stratum.

[0059] The above are all the preferred embodiments of this application, and the protection scope of this application is not limited accordingly. Therefore, all equivalent changes made according to the structure, shape, and principle of this application should be covered within the protection scope of this application.

Claims

1. A high-pressure jet grouting bit for cobble stratum, characterized in that: It includes a drill pipe connection base (1), the drill pipe connection base (1) is of a hollow structure, a first tooth seat (2) is coaxially fixed on the drill pipe connection base (1), a slurry outlet hole (21) is formed in the first tooth seat (2), a part of the slurry outlet hole (21) communicates with the inside of the drill pipe connection base (1), a part of the slurry outlet hole (21) extends out of the drill pipe connection base (1), at least two second tooth seats (3) are fixed on the circumferential surface of the drill pipe connection base (1), the circumferential surface of the second tooth seat (3) is connected to the circumferential surface of the drill pipe connection base (1), pick teeth (4) are installed on both the first tooth seat (2) and the second tooth seat (3), the central axis of the pick teeth (4) on the first tooth seat (2) has a staggered angle with the central axis of the pick teeth (4) on the second tooth seat (3), and the central axis of the pick teeth (4) on the first tooth seat (2) and the central axis of the pick teeth (4) on the second tooth seat (3) are skew lines.

2. The high-pressure jet grouting bit for cobble stratum according to claim 1, characterized in that: The tip of the pick teeth (4) on the second tooth seat (3) has a deviation angle deviating away from the central axis direction of the drill pipe connection base (1).

3. The high-pressure jet grouting bit for cobble stratum according to claim 2, characterized in that: The staggered angle between the central axis of the pick teeth (4) on the first tooth seat (2) and the central axis of the pick teeth (4) on the second tooth seat (3) is 45°, and the central axis of the pick teeth (4) on the second tooth seat (3) deflects in the clockwise direction; The deviation angle of the tip of the pick teeth (4) on the second tooth seat (3) is 5°.

4. The high-pressure jet grouting bit for cobble stratum according to claim 1, characterized in that: The horizontal plane where the tip of the pick teeth (4) on the second tooth seat (3) is located is farther from the drill pipe connection base (1) than the horizontal plane where the installation end of the pick teeth (4) on the first tooth seat (2) is located.

5. The high-pressure jet grouting bit for cobble stratum according to any one of claims 1-4, characterized in that: A guide plate (6) is connected to the bottoms of the two second tooth seats (3), one side of the guide plate (6) is fixed to the drill pipe connection base (1), the side of the guide plate (6) away from the drill pipe connection base (1) is set as an arc-shaped guide surface (61), the guide plate (6) is inclined, and the end of the guide plate (6) connected to the second tooth seat (3) is closer to the first tooth seat (2) than the other end of the guide plate (6).

6. The high-pressure jet grouting bit for cobble stratum according to any one of claims 1-4, characterized in that: A protective plate (7) is connected to the circumferential surface of the second tooth seat (3), one end of the protective plate (7) is fixed to the circumferential surface of the second tooth seat (3), the other end of the protective plate (7) is fixed to the drill pipe connection base (1), and the protective plate (7) is arranged on one side of the second tooth seat (3) in the rotation direction relative to the drill pipe connection base (1).

7. The high-pressure jet grouting bit for cobble stratum according to claim 6, wherein: A filling plate (8) is fixed on the drill pipe connection base (1), the filling plate (8) fills the space between the protective plate (7) and the drill pipe connection base (1) and the space between the second tooth seat (3) and the drill pipe connection base (1), and the filling plate (8) is connected to the second tooth seat (3) and the protective plate (7).

8. The high-pressure jet grouting bit for cobble stratum according to claim 1, wherein: Several wear-resistant points (41) are arranged on the circumferential surface of the pick teeth (4) near its tip.

9. The high-pressure jet grouting bit for cobble stratum according to claim 1, characterized in that: The first tooth seat (2) and the second tooth seat (3) are connected by a connecting plate (5).

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