A drill bit for a drill rig and a long auger drill rig using the drill bit

Abstract

This utility model provides a drill bit and a long spiral drilling rig using the drill bit, relating to the technical field of long spiral drilling rigs. It includes: a central tube, a first spiral blade, a second spiral blade, and a drill bit assembly. The top and bottom ends of the central tube are a flange connection end and a sealing end, respectively. The first and second spiral blades are symmetrically spirally wound around the outside of the central tube with the same pitch, with the upper end of the first and second spiral blades being the starting end and the lower end being the ending end. The drill bit assembly includes a central drill bit group, a first side drill bit group, a second side drill bit group, and two auxiliary drill bit groups. This utility model, through the three-dimensional distribution of the central drill bit group, the first side drill bit group, the second side drill bit group, and the auxiliary drill bit groups, forms a multi-stage fracturing structure capable of penetrating 200-300mm into rock, effectively fracturing the rock mass and improving the drilling efficiency in hard rock formations. It has a compact structure, strong practicality, and is conducive to market promotion.

Description

Technical Field

[0001] This utility model relates to the field of long spiral drilling rig technology, and more specifically, to a drilling rig bit and a long spiral drilling rig using the drilling bit. Background Technology

[0002] Long auger drilling rigs, as highly efficient hole-forming equipment, are widely used in building pile foundation engineering, geological exploration, and other fields. Their characteristic of simultaneously completing the cutting and soil transport through the rotation of the auger rod offers significant advantages in loose strata such as soft soil and sand. However, when encountering moderately weathered or harder rock formations, the drilling efficiency of conventional long auger drilling rigs drops sharply, and existing drill bits are insufficient to effectively break the rock mass. Often, it is necessary to switch to rotary drilling rigs or impact drilling rigs for follow-up construction, leading to frequent equipment changes, extended construction cycles, and increased costs. Utility Model Content

[0003] The purpose of this invention is to provide a drill bit and a long spiral drilling rig using the drill bit, which can effectively break rock and improve drilling efficiency in hard rock formations.

[0004] In a first aspect, this utility model provides a drill bit for a drilling rig, comprising: a central tube, the top end of which is a flange connection end for fixed connection with the output shaft of the drilling rig, and the bottom end is a sealing end; The first and second helical blades are symmetrically wound around the outside of the central tube with the same pitch. The upper end of the first and second helical blades is the starting end, and the lower end is the ending end. The drill bit assembly includes a central drill bit assembly fixedly disposed at the bottom end of the central tube, a first side drill bit assembly and a second side drill bit assembly respectively disposed at the end ends of the first helical blade and the second helical blade, and two auxiliary drill bit assemblies respectively fixedly disposed on both sides of the bottom end of the central tube.

[0005] Furthermore, each of the two sets of auxiliary drill bit groups includes at least one auxiliary drill bit. Both sides of the bottom end of the central tube are provided with auxiliary drill bit mounting seats. An auxiliary drill bit fixing seat is provided on the auxiliary drill bit mounting seat. The auxiliary drill bit is fixedly connected to the auxiliary drill bit fixing seat. The bottom ends of the two auxiliary drill bits are provided with a first inclined surface that is inclined downward and extends away from the central drill bit group.

[0006] Furthermore, each of the two auxiliary drill bits is provided with a second inclined surface that slopes downward and extends toward the central drill bit assembly. The length of the first inclined surface is greater than the length of the second inclined surface, and the first and second inclined surfaces cooperate to form a cutting edge at the bottom of the auxiliary drill bit.

[0007] Furthermore, the central drill bit group includes at least three central drill bits, and the first side drill bit group and the second side drill bit group each include at least two first side drill bits and at least two second side drill bits; At least three central drill bits are arranged in a circumferential spiral array at the bottom end of the central tube, and at least two first side drill bits and at least two second side drill bits are respectively arranged along the spiral direction of the first spiral blade and the second spiral blade.

[0008] Furthermore, the end of the central tube is provided with a central drill bit fixing seat for fixing the central drill bit, and the termination ends of the first helical blade and the second helical blade are respectively provided with a first side drill bit fixing seat and a second side drill bit fixing seat for fixing the first side drill bit and the second side drill bit.

[0009] Furthermore, a reinforcing plate is provided at the end of both the first and second helical blades.

[0010] Furthermore, multiple ribs are evenly distributed circumferentially between the flange connection end of the central tube and the starting ends of the first and second helical blades.

[0011] Furthermore, guide grooves are provided on the outer edges of both the first and second helical blades. Furthermore, the guide channel includes a first inner wall that is inclined downward relative to the first or second helical blade and a second inner wall that is inclined upward relative to the first or second helical blade, and the width of the first inner wall is greater than the width of the second inner wall.

[0012] Secondly, this utility model also provides a long spiral drilling rig, including a drilling rig body, the drilling rig body including an output shaft, and the bottom end of the output shaft is connected to the drilling bit as described above.

[0013] The technical solution of this utility model has at least the following advantages and beneficial effects: This application utilizes a three-dimensional distribution of a central drill bit assembly, a first side drill bit assembly, a second side drill bit assembly, and an auxiliary drill bit assembly to form a multi-stage fracturing structure capable of penetrating 200-300mm into the rock. Simultaneously, the symmetrically arranged first and second helical blades optimize the soil removal path, reducing the impact of cuttings accumulation on drilling efficiency. This enables efficient drilling in moderately weathered hard rock formations, reduces equipment changeover frequency, shortens the construction cycle, and lowers overall costs. The structure is compact, highly practical, and conducive to market promotion. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the overall structure of this utility model; Figure 2 This is a bottom view of the present invention; Figure 3 In this utility model Figure 1 Another perspective view; Figure 4 In this utility model Figure 3 An enlarged view of part A in the image.

[0015] Reference numerals: 10, central tube; 11, flange connection end; 12, rib plate; 20, first helical blade; 21, reinforcing plate; 30, second helical blade; 41, central drill bit assembly; 411, central drill bit; 412, central drill bit mounting base; 42, first side drill bit assembly; 421, first side drill bit; 422, first side drill bit mounting base; 43, second side drill bit assembly; 431, second side drill bit; 432, second side drill bit mounting base; 44, auxiliary drill bit assembly; 441, auxiliary drill bit; 4411, first inclined surface; 4412, second inclined surface; 4413, cutting edge; 442, auxiliary drill bit mounting base; 443, auxiliary drill bit mounting base; 50, guide channel; 51, first inner wall; 52, second inner wall. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0017] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention. Example

[0018] The following is for reference Figures 1-4 As shown in the figure, in conjunction with a specific embodiment, this embodiment provides a drilling bit, including a central tube 10, a first helical blade 20 and a second helical blade 30, and a drill bit assembly. The top end of the central tube 10 is a flange connection end 11 for fixed connection with the output shaft of the drilling rig, and the bottom end is a sealing end. The first helical blade 20 and the second helical blade 30 are symmetrically spirally wound around the outside of the central tube 10 with the same pitch, and the upper end of the first helical blade 20 and the second helical blade 30 is the starting end and the lower end is the ending end; the drill bit assembly includes a central drill bit group 41 fixedly disposed at the bottom end of the central tube 10, a first side drill bit group 42 and a second side drill bit group 43 respectively disposed at the ending ends of the first helical blade 20 and the second helical blade 30, and two auxiliary drill bit groups 44 respectively fixedly disposed on both sides of the bottom end of the central tube 10.

[0019] Specifically, the central tube 10 refers to an axially continuous hollow tubular structure, which can be made of alloy steel. The flange connection end 11 is rigidly connected to the output shaft of the drilling rig by bolts, and the sealing end can seal the bottom of the tube to prevent rock cuttings from flowing back in. The first helical blade 20 and the second helical blade 30 refer to a strip structure symmetrically arranged with the same rotation direction and pitch, which can be made by segmented welding or integral casting. The helical winding method is beneficial to improving soil removal efficiency. The central drill bit group 41 in the drill bit assembly refers to multiple cutting units distributed circumferentially along the bottom end of the central tube 10. The first side drill bit group 42 and the second side drill bit group 43 are distributed at the terminating ends of the first helical blade 20 and the second helical blade 30 to expand the cutting range. The auxiliary drill bit group 44 is installed on both sides of the bottom end of the central tube 10 to enhance the edge breaking ability.

[0020] Understandably, this application forms a multi-stage fracturing structure through the three-dimensional distribution of the central drill bit group 41, the first side drill bit group 42, the second side drill bit group 43, and the auxiliary drill bit group 44. At the same time, the symmetrically arranged first spiral blade 20 and second spiral blade 30 optimize the soil removal path and reduce the impact of rock cuttings accumulation on drilling efficiency, thereby achieving efficient drilling in moderately weathered hard rock layers, reducing equipment changeover frequency, and thus shortening the construction cycle and reducing overall costs.

[0021] Furthermore, each auxiliary drill bit assembly 44 includes at least one auxiliary drill bit 441. Both sides of the bottom end of the central tube 10 are provided with auxiliary drill bit mounting seats 442. An auxiliary drill bit fixing seat 443 is provided on the auxiliary drill bit mounting seat 442. The auxiliary drill bit 441 is fixedly connected to the auxiliary drill bit fixing seat 443. The bottom end of each of the two auxiliary drill bits 441 is provided with a first inclined surface 4411 that is inclined downward and extends away from the central drill bit assembly 41.

[0022] Understandably, the auxiliary drill bit 441 is mounted on the auxiliary drill bit mounting seats 442 on both sides of the bottom end of the central tube 10 via the auxiliary drill bit fixing seat 443, forming a symmetrically distributed structure. When the auxiliary drill bit 441 rotates and cuts into the rock strata, the first inclined surface 4411 contacts the rock mass at an outward tilting angle, converting part of the axial pressure into lateral shear force, thereby forming a progressive fracturing path in the hard rock strata and reducing drilling resistance. The rigid connection between the auxiliary drill bit fixing seat 443 and the auxiliary drill bit mounting seat 442 can avoid displacement caused by vibration during drilling, while the synergistic effect of multiple auxiliary drill bits 441 can improve the continuity and stability of rock fracturing.

[0023] In one specific embodiment, the auxiliary drill bit assembly 44 includes one auxiliary drill bit 441. In other embodiments, the number of auxiliary drill bits 441 may be two or more. The specific number can be adjusted according to the actual situation, and no further limitation is made here.

[0024] Furthermore, the bottom ends of both auxiliary drill bits 441 are provided with a second inclined surface 4412 that is inclined downward and extends toward the middle drill bit assembly 41. The length of the first inclined surface 4411 is greater than the length of the second inclined surface 4412, and the first inclined surface 4411 and the second inclined surface 4412 cooperate at the bottom end of the auxiliary drill bit 441 to form a cutting edge 4413.

[0025] Understandably, this design incorporates both outward and inward inclined cutting surfaces at the bottom of the auxiliary drill bit 441. The outward-facing first inclined surface 4411 primarily functions to break rocks, and its longer length increases the contact area with the rock strata. The inward-facing second inclined surface 4412 serves as an auxiliary cutting structure, creating a bidirectional cutting action as the drill bit rotates. The cutting edge 4413 formed at the intersection of the first and second inclined surfaces 4411 generates a stress concentration effect during drilling, enabling rapid penetration into the rock surface. Combined with the combined cutting force generated by the first and second inclined surfaces 4411 and 4412, this effectively breaks up rock masses of moderate weathering hardness and above.

[0026] Furthermore, the central drill bit group 41 includes at least three central drill bits 411, the first side drill bit group 42 and the second side drill bit group 43 respectively include at least two first side drill bits 421 and at least two second side drill bits 431; at least three central drill bits 411 are distributed in a circumferential spiral array at the bottom end of the central tube 10, and at least two first side drill bits 421 and at least two second side drill bits 431 are respectively arranged along the spiral direction of the first spiral blade 20 and the second spiral blade 30.

[0027] The three central drill bits 411 in the circumferential spiral array at the bottom of the central tube 10 form the core fracturing zone, generating continuous and staggered cutting trajectories during rotation. The first side drill bits 421 and 431, respectively mounted on the first spiral blade 20 and the second spiral blade 30, extend along the spiral direction, aligning with the advancing direction of the first spiral blade 20 and the second spiral blade 30. When the drill bits rotate, the central drill bit 411 is responsible for fracturing the central area of ​​the rock strata, while the first side drill bits 421 and 431 follow the movement trajectory of the first spiral blade 20 and the second spiral blade 30 to synchronously cut the surrounding rock strata. The fractured rock fragments are directly transported upwards by the spiral blades.

[0028] Understandably, by adopting the above technical solution, this application effectively improves the crushing efficiency of hard rock formations. The helical array distribution of the central drill bit 411 enhances the continuous crushing capability of the central region. The coordinated arrangement of the first side drill bit 421 and the second side drill bit 431 with the first helical blade 20 and the second helical blade 30 reduces drill bit swaying and allows the crushed rock cuttings to be promptly discharged by the first helical blade 20 and the second helical blade 30. This structure is particularly suitable for moderately weathered rock formations, avoiding frequent equipment replacements caused by unreasonable drill bit structures.

[0029] Furthermore, the end of the central tube 10 is provided with a central drill bit fixing seat 412 for fixing the central drill bit 411, and the termination ends of the first helical blade 20 and the second helical blade 30 are respectively provided with a first side drill bit fixing seat 422 and a second side drill bit fixing seat 432 for fixing the first side drill bit 421 and the second side drill bit 431.

[0030] Through the above technical solution, this application effectively solves the problem of low cutting efficiency caused by unstable drill bit fixation during drilling in hard rock formations, improves the overall stability and maintenance convenience of drill bit assembly, thereby extending the service life of drill bit and reducing construction costs.

[0031] Furthermore, it is proposed that a reinforcing plate 21 be provided at the termination end of both the first helical blade 20 and the second helical blade 30.

[0032] Compared to existing technologies, traditional long auger drill bits only increase strength by increasing the thickness of the auger blades, but this results in increased weight and decreased slag removal efficiency. This solution, while maintaining the original thickness of the first auger blade 20 and the second auger blade 30, adds reinforcing plates 21 to the termination ends of the first auger blade 20 and the second auger blade 30, forming a double-support structure in key stress concentration areas. Compared to drill bits without reinforcing plates 21, this design increases the bending strength of the blade termination ends by approximately 2.3 times, while avoiding the additional load on the drilling rig's power system due to the increased overall weight.

[0033] Furthermore, multiple ribs 12 are evenly distributed circumferentially between the flange connection end 11 of the central tube 10 and the starting ends of the first helical blade 20 and the second helical blade 30.

[0034] Specifically, the rib plate 12 is located in the transition area between the flange connection end 11 and the starting end of the helical blade. When the drill bit rotates and drills, the flange connection end 11 bears the torque and axial pressure of the drill rig's output shaft, while the starting ends of the first helical blade 20 and the second helical blade 30 bear the reverse force generated by soil cutting. Through its circumferentially distributed layout, the rib plate 12 disperses and transfers the load of the flange connection end 11 to the starting ends of the first helical blade 20 and the second helical blade 30, avoiding structural deformation or fracture caused by local stress concentration.

[0035] Furthermore, both the first helical blade 20 and the second helical blade 30 have guide grooves 50 along their outer edges. The guide groove 50 is a groove structure that extends continuously along the outer edge of the helical blade. Specifically, it can be formed into a groove with a specific cross-sectional shape on the outer side of the blade using machining or casting processes. This guide groove 50 guides the flow direction of rock cuttings, preventing debris from accumulating between the blade and the borehole wall.

[0036] During drilling, the rock cuttings generated by the rotation of the first helical blade 20 and the second helical blade 30 move outward under centrifugal force. The guide channel 50 guides the rock cuttings into the channel through its groove structure and transports them upward along the helical direction. Because the guide channel 50 is located on the outer edge of the first helical blade 20 and the second helical blade 30, it forms a chip removal channel in the area directly in contact with the borehole wall, allowing large rock cuttings to be effectively captured and quickly discharged, reducing energy loss caused by repeated crushing. At the same time, the presence of the guide channel 50 reduces the friction area between the outer edge of the first helical blade 20 and the second helical blade 30 and the borehole wall, avoiding torque fluctuations caused by rock cuttings getting stuck.

[0037] Furthermore, the guide channel 50 includes a first inner wall 51 that is inclined downward relative to the first helical blade 20 or the second helical blade 30 and a second inner wall 52 that is inclined upward relative to the first helical blade 20 and the second helical blade 30, and the width of the first inner wall 51 is greater than the width of the second inner wall 52.

[0038] As the drill bit rotates and cuts into the rock formation, the broken rock cuttings move along the guide channel 50 under the propulsion of the helical blades. The downward-sloping structure of the first inner wall 51 guides the cuttings to slide downwards rapidly, and the wider design increases the volume of the guide channel. The upward-sloping structure of the second inner wall 52 forms an upward guide surface when the first helical blade 20 and the second helical blade 30 rotate, which, together with the first inner wall 51, forms a directional flow channel, thereby greatly improving the cuttings removal efficiency.

[0039] In addition, this embodiment also provides a long spiral drilling rig, including a drilling rig body, the drilling rig body including an output shaft, and the bottom end of the output shaft is connected to the drilling bit as described above.

[0040] The above are merely preferred embodiments of this utility model and are not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A drill bit for a drill, characterized in that include: The central tube (10) has a flange connection end (11) at its top end for fixed connection with the output shaft of the drilling rig, and a sealing end at its bottom end. The first helical blade (20) and the second helical blade (30) are symmetrically spirally wound around the outside of the central tube (10) with the same pitch. The upper end of the first helical blade (20) and the lower end of the second helical blade (30) are the starting end and the ending end, respectively. The drill bit assembly includes a central drill bit assembly (41) fixedly disposed at the bottom end of the central tube (10), a first side drill bit assembly (42) and a second side drill bit assembly (43) respectively disposed at the end ends of the first helical blade (20) and the second helical blade (30), and two auxiliary drill bit assemblies (44) respectively fixedly disposed on both sides of the bottom end of the central tube (10).

2. A drill bit according to claim 1, wherein, Both sets of auxiliary drill bit groups (44) include at least one auxiliary drill bit (441). Auxiliary drill bit mounting seats (442) are provided on both sides of the bottom end of the central tube (10). An auxiliary drill bit fixing seat (443) is provided on the auxiliary drill bit mounting seat (442). The auxiliary drill bit (441) is fixedly connected to the auxiliary drill bit fixing seat (443). The bottom ends of the two auxiliary drill bits (441) are provided with a first inclined surface (4411) that is inclined downward and extends away from the central drill bit group (41).

3. A drill bit according to claim 2, wherein, The bottom ends of the two auxiliary drill bits (441) are also provided with a second inclined surface (4412) that is inclined downward and extends toward the middle drill bit assembly (41). The length of the first inclined surface (4411) is greater than the length of the second inclined surface (4412), and the first inclined surface (4411) and the second inclined surface (4412) cooperate to form a cutting edge (4413) at the bottom end of the auxiliary drill bit (441).

4. A drill bit according to claim 1, wherein, The central drill bit group (41) includes at least three central drill bits (411), and the first side drill bit group (42) and the second side drill bit group (43) respectively include at least two first side drill bits (421) and at least two second side drill bits (431); At least three central drill bits (411) are arranged in a circumferential spiral array at the bottom end of the central tube (10), and at least two first side drill bits (421) and at least two second side drill bits (431) are respectively arranged along the spiral direction of the first spiral blade (20) and the second spiral blade (30).

5. A drill bit according to claim 1 wherein, The end of the central tube (10) is provided with a central drill bit fixing seat (412) for fixing the central drill bit (411), and the first helical blade (20) and the second helical blade (30) are respectively provided with a first side drill bit fixing seat (422) and a second side drill bit fixing seat (432) for fixing the first side drill bit (421) and the second side drill bit (431).

6. A drill bit according to claim 1 wherein, A reinforcing plate (21) is provided at the end of both the first helical blade (20) and the second helical blade (30).

7. A drill bit according to claim 1 wherein, Multiple ribs (12) are evenly distributed circumferentially between the flange connection end (11) of the central tube (10) and the starting end of the first helical blade (20) and the second helical blade (30).

8. A drill bit according to claim 1 wherein, The first helical blade (20) and the second helical blade (30) are both provided with guide grooves (50) on their outer edges.

9. A drill bit according to claim 8, wherein, The guide groove (50) includes a first inner wall (51) that is inclined downward relative to the first helical blade (20) or the second helical blade (30) and a second inner wall (52) that is inclined upward relative to the first helical blade (20) or the second helical blade (30), and the width of the first inner wall (51) is greater than the width of the second inner wall (52).

10. An auger drill rig characterized in that, The system includes a drilling rig body, the drilling rig body including an output shaft, the bottom end of which is connected to a drilling rig bit as described in any one of claims 1-9.

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