Combined anchor rod drill bit

Abstract

The utility model discloses a combined anchor rod drill bit which comprises a first-stage drill bit and a second-stage drill bit which are connected and have increased diameters, the first-stage drill bit comprises a plurality of first-stage drill bit blades, a first-stage drill bit runner groove is formed between every two adjacent first-stage drill bit blades, a two-layer stepped structure with the radial size sequentially increased is formed by the first-stage drill bit and the second-stage drill bit, and the hole forming diameter of the drill bit is the radial superposition of the hole drilling diameter of the first-stage drill bit and the hole drilling diameter of the second-stage drill bit; the first-stage drill bit with the small diameter is used for conducting pilot hole preliminary drilling, then the second-stage drill bit with the large diameter is used for conducting hole completion drilling, the size of rock crushed by the drill bits at a time can be reduced, the difficulty that the first-stage drill bit penetrates into hard rock is lowered, and premature abrasion of the first-stage drill bit is avoided; in addition, small holes drilled by the first-stage drill bit provide guiding and supporting for the second-stage drill bit, the second-stage drill bit can maintain a stable drilling track more easily in the reaming process, and the technical problem that an existing anchor rod drill bit is poor in drilling stability is solved.

Description

Technical Field

[0001] The utility model belongs to the technical field of underground drilling construction in coal mines and relates to an anchor drill bit, in particular to a combined anchor drill bit. Background Art

[0002] As a core component of support systems for underground coal mine tunnels, railway tunnels, foundation pit slopes, and other structures, the quality of anchor drilling directly impacts the effectiveness of anchoring. Therefore, achieving high-quality anchor drilling is crucial. As a key component in anchor drilling, the anchor drill bit plays a decisive role in drilling efficiency and construction quality. Currently, most PDC anchor drill bits used in construction have a two-wing structure. This creates significant resistance when drilling hard rock, resulting in poor drilling stability and a high risk of wear and breakage of the PDC cutters. This shortens the drill bit life and reduces drilling efficiency. Summary of the Invention

[0003] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a combined anchor drill bit to solve the technical problems of poor drilling stability and low efficiency of the existing anchor drill bits.

[0004] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0005] A combined anchor drill bit comprises a first-stage drill bit and a second-stage drill bit connected and having increased diameters;

[0006] The first-stage drill bit includes a plurality of first-stage drill blades, a first-stage drill flow channel groove is provided between adjacent first-stage drill blades, a central water hole arranged along the axial direction is provided at the radial center of the first-stage drill bit; a first cutting tooth pocket is provided on one side of the top of each first-stage drill blade;

[0007] The secondary drill bit includes a body connected to the primary drill blade, the body is provided with a plurality of secondary drill blades, a top side of each secondary drill blade is provided with a second cutting tooth pocket, a gauge surface of the secondary drill blade is provided with a gauge mounting groove, and a gauge alloy is provided in the gauge mounting groove; a central through hole arranged along the axial direction is provided at the radial center of the secondary drill blade; a secondary drill flow channel groove is formed between adjacent secondary drill blades, an outer ring water hole is provided on the secondary drill flow channel groove, and the outer ring water hole is communicated with the upper half of the central through hole;

[0008] PDC cutting teeth are installed on both the first cutting tooth pocket and the second cutting tooth pocket.

[0009] The utility model also includes the following technical features:

[0010] The first-stage drill bit and the second-stage drill bit are connected by threads.

[0011] The number of the first-stage drill blades is 2 to 3.

[0012] The number of the secondary drill blades is 2 to 4.

[0013] The angle between the end face of the PDC cutting tooth and the central axis of the secondary drill bit is 5 to 15 degrees.

[0014] The diameter of the upper half of the central through hole is smaller than that of the lower half.

[0015] The included angle between the outer ring water hole and the central axis of the secondary drill bit is 20 to 60 degrees.

[0016] The height difference between the top surface of the first-stage drill bit and the top surface of the second-stage drill bit is 15 to 30 mm.

[0017] The diameter ratio of the first-stage drill bit to the second-stage drill bit is 0.5 to 0.8.

[0018] Compared with the prior art, the present invention has the following beneficial technical effects:

[0019] (I) The present invention adopts a two-layer stepped structure with radial dimensions increasing successively, consisting of a first-stage drill bit and a second-stage drill bit. The hole diameter of the drill bit is the radial superposition of the drilling diameter of the first-stage drill bit and the drilling diameter of the second-stage drill bit. The first-stage drill bit with a smaller diameter is used for pilot drilling, and then the second-stage drill bit with a larger diameter is used for completing the hole. This is beneficial to reducing the volume of rock crushed by the drill bit at one time, greatly reducing the difficulty of the first-stage drill bit eating into hard rock, making the drilling pressure and torque required for the first-stage drill bit to crush rock relatively low, which is beneficial to reducing the intensity and frequency of its direct impact on hard rock, protecting the first-stage drill bit and avoiding its premature wear. In addition, the small hole drilled by the first-stage drill bit provides guidance and support for the second-stage drill bit, and the second-stage drill bit is more likely to maintain a stable drilling trajectory during the hole expansion process, thereby reducing the vibration and deviation of the drill bit, and solving the technical problem of poor drilling stability of existing anchor drill bits.

[0020] (II) The primary crushing of rock by the first-stage drill bit in the present invention is conducive to weakening the rock strength, destroying the overall structural stress of the rock, and greatly reducing the energy required for the second-stage drill bit to crush the rock, thereby improving the overall drilling efficiency of the device, extending the life of the drill bit, reducing construction costs, ensuring construction efficiency, and solving the technical problem of low drilling efficiency of existing anchor drill bits. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a three-dimensional schematic diagram of the utility model;

[0022] Figure 2 It is a cutaway view of the utility model;

[0023] Figure 3 It is a partial three-dimensional structural schematic diagram of the utility model.

[0024] The reference numerals in the figure indicate: 1-first-stage drill bit, 2-second-stage drill bit, 3-PDC cutting tooth, 4-gauge alloy; 11-first-stage drill bit blade, 12-center water hole, 13-first-stage drill bit flow channel groove, 14-first-stage drill bit cutting tooth pocket;

[0025] 21-secondary drill blade, 22-secondary drill inner hole, 23-outer ring water hole, 24-secondary drill flow channel groove, 25-secondary drill cutting tooth pocket, 26-diameter mounting groove, 27-body.

[0026] The specific contents of the present invention are further explained in detail below with reference to the embodiments. DETAILED DESCRIPTION

[0027] It should be noted that, unless otherwise specified, all components in the present invention are components known in the art.

[0028] The following are specific embodiments of the present invention. It should be noted that the present invention is not limited to the following specific embodiments, and all equivalent modifications made on the basis of the technical solution of this application fall within the scope of protection of the present invention.

[0029] The utility model provides a combined anchor drill bit, comprising a first-stage drill bit 1 and a second-stage drill bit 2, which are connected and have an increased diameter. The first-stage drill bit 1 comprises a plurality of first-stage drill blades 11, with first-stage drill flow channel grooves 13 provided between adjacent first-stage drill blades 11. A central water hole 12 arranged along the axial direction is provided at the radial center of the first-stage drill bit 1. A first cutting tooth pocket 14 is provided on one side of the top of each first-stage drill blade 11.

[0030] The secondary drill bit 2 includes a body 27 connected to the primary drill blade 11. The body 27 is provided with a plurality of secondary drill blades 21. A second cutting tooth pocket 25 is provided on one side of the top of each secondary drill blade 21. A gauge mounting groove 26 is provided on the gauge surface of the secondary drill blade 21. A gauge alloy 4 is provided in the gauge mounting groove 26. A central through hole 22 arranged along the axial direction is provided at the radial center of the secondary drill blade 21. Secondary drill flow channel grooves 24 are formed between adjacent secondary drill blades 21. The secondary drill flow channel grooves 24 are provided with outer ring water holes 23. The outer ring water holes 23 are connected to the upper half of the central through hole 22.

[0031] The first cutting tooth pocket 14 and the second cutting tooth pocket 25 are both mounted with PDC cutting teeth 3 .

[0032] In the above technical solution, a two-layer stepped structure with successively increasing radial dimensions is adopted, consisting of a first-level drill bit 1 and a second-level drill bit 2. The hole diameter of the drill bit is the radial superposition of the drilling diameter of the first-level drill bit and the drilling diameter of the second-level drill bit. The first-level drill bit with a smaller diameter is used for preliminary pilot drilling, and then the second-level drill bit with a larger diameter is used for complete hole drilling. This is beneficial to reducing the volume of rock crushed by the drill bit at one time, greatly reducing the difficulty of the first-level drill bit to penetrate hard rock, and making the drilling pressure and torque required for the first-level drill bit to crush rock relatively low, which is beneficial to reducing the intensity and frequency of its direct impact on hard rock, protecting the first-level drill bit and avoiding its premature wear; in addition, the small hole drilled by the first-level drill bit provides guidance and support for the second-level drill bit, and the second-level drill bit is more likely to maintain a stable drilling trajectory during the hole expansion process, thereby reducing the vibration and deviation of the drill bit, and solving the technical problem of poor drilling stability of the existing anchor drill bit.

[0033] The first-stage drill bit 1 and the second-stage drill bit 2 are connected by threads.

[0034] In the above technical solution, the threaded connection facilitates installation and disassembly.

[0035] The number of the first-stage drill blades 11 is 2 to 3.

[0036] In the above technical solutions, based on experience, 2 are preferred.

[0037] The number of the secondary drill blades 21 is 2 to 4.

[0038] In the above technical solutions, based on experience, 3 are preferred.

[0039] The angle between the end face of the PDC cutting tooth 3 and the central axis of the secondary drill bit (2) is 5 to 15 degrees.

[0040] In the above technical solution, within the range of 5 to 15°, the cutting effect of the PDC cutting teeth 3 is better.

[0041] The diameter of the upper half of the central through hole 22 is smaller than that of the lower half.

[0042] In the above technical solution, because the first-level drill bit 1 and the second-level drill bit 2 are connected by male and female threads, the through-hole diameter of the first-level drill bit must be slightly smaller than the diameter of the second-level through-hole. Therefore, the diameter of the upper half of the center through-hole 22 is smaller than the lower half, and the diameter of the lower half of the center through-hole 22 is larger to facilitate water circulation.

[0043] The included angle between the outer ring water hole 23 and the central axis of the secondary drill bit 2 is 20-60 degrees.

[0044] In the above technical solution, based on experience, 45° is preferred.

[0045] The height difference between the top surface of the primary drill bit 1 and the top surface of the secondary drill bit 2 is 15 to 30 mm.

[0046] In the above technical solution, the value of 15 to 30 mm is based on the following: if the height difference is too small, the stress of the pilot hole drilled by the first-level drill bit 1 has not been completely released during the drilling process, and the second-level drill bit 2 can start drilling, which is not conducive to the complete release of the stress of the pilot hole rock; if it is too large, the size of the entire drill bit is too large.

[0047] The diameter ratio of the first-stage drill bit 1 and the second-stage drill bit 2 is 0.5 to 0.8.

[0048] In the above technical solution, the specific value of the diameter ratio is determined according to actual needs.

Claims

1. A combined anchor drill bit, characterized in that: It comprises a first-stage drill bit (1) and a second-stage drill bit (2) connected and having increased diameters; The first-stage drill bit (1) comprises a plurality of first-stage drill blades (11), a first-stage drill flow channel groove (13) is provided between adjacent first-stage drill blades (11), a central water hole (12) arranged along the axial direction is provided at the radial center of the first-stage drill bit (1); a first cutting tooth pocket (14) is provided on one side of the top of each first-stage drill blade (11); The secondary drill bit (2) comprises a body (27) connected to the primary drill blade (11), a plurality of secondary drill blades (21) are provided on the body (27), a second cutting tooth pocket (25) is provided on one side of the top of each secondary drill blade (21), a diameter-guarding mounting groove (26) is provided on the diameter-guarding surface of the secondary drill blade (21), and a diameter-guarding alloy (4) is provided in the diameter-guarding mounting groove (26); a central through hole (22) arranged along the axial direction is provided at the radial center of the secondary drill blade (21); a secondary drill flow channel groove (24) is formed between adjacent secondary drill blades (21), an outer ring water hole (23) is provided on the secondary drill flow channel groove (24), and the outer ring water hole (23) is communicated with the upper half of the central through hole (22); PDC cutting teeth (3) are installed on both the first cutting tooth pocket (14) and the second cutting tooth pocket (25).

2. The combined anchor drill bit according to claim 1, characterized in that: The first-stage drill bit (1) and the second-stage drill bit (2) are connected by threads.

3. The combined anchor drill bit according to claim 1, characterized in that: The number of the first-stage drill blades (11) is 2 to 3.

4. The combined anchor drill bit according to claim 1, characterized in that: The number of the secondary drill blades (21) is 2 to 4.

5. The combined anchor drill bit according to claim 1, characterized in that: The angle between the end face of the PDC cutting tooth (3) and the central axis of the secondary drill bit (2) is 5 to 15 degrees.

6. The combined anchor drill bit according to claim 1, characterized in that: The diameter of the upper half of the central through hole (22) is smaller than that of the lower half.

7. The combined anchor drill bit according to claim 1, characterized in that: The angle between the outer ring water hole (23) and the central axis of the secondary drill bit (2) is 20 to 60 degrees.

8. The combined anchor drill bit according to claim 1, characterized in that: The height difference between the top surface of the first-stage drill bit (1) and the top surface of the second-stage drill bit (2) is 15 to 30 mm.

9. The combined anchor drill bit according to claim 1, characterized in that: The diameter ratio between the first-stage drill bit (1) and the second-stage drill bit (2) is 0.5 to 0.8.

Images