A down-the-hole hammer drill and method of operation

Abstract

This invention discloses a down-the-hole hammer drill bit and its working method, which solves the problem of large inclination angle of the down-the-hole hammer drill bit in the prior art and has the beneficial effect of ensuring the verticality of the borehole during pressurized drilling. The specific solution is as follows: A down-the-hole hammer drill bit includes an outer sleeve, at least two support members are provided inside the outer sleeve, and the support members are spaced apart. The support members are provided with openings. The multiple support members support the down-the-hole hammer rod body and the inner sleeve connected to the down-the-hole hammer rod body through the openings. A connector is provided at the end of the inner sleeve away from the down-the-hole hammer rod body to connect with the drill rod. The down-the-hole hammer drill bit of the down-the-hole hammer rod body protrudes from one end of the outer sleeve. The other end of the outer sleeve is provided with a bevel to facilitate the removal of the stuck part in the borehole during the rotation of the outer sleeve. A reduced diameter section is provided at the end of the inner sleeve away from the down-the-hole hammer rod body. The reduced diameter section is connected to the connector. A flange is provided circumferentially on the reduced diameter section to connect with the same support member.

Description

Technical Field

[0001] This invention relates to the field of drilling, and in particular to a down-the-hole hammer drill and its working method. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] During down-the-hole (DH) drilling, due to the inherent characteristics of DH hammer drill bits, the diameter of the DH hammer shaft differs significantly from the drill bit diameter, resulting in a relatively short shaft length, typically 1.2 to 1.5 meters. (Reference) Figure 1 As shown, due to the flexibility of the drill pipe connected to the upper part of the down-the-hole hammer drill bit, a lateral force P is generated at the top of the down-the-hole hammer rod during pressurized drilling. This lateral force causes the top of the down-the-hole hammer drill bit to lean towards the well wall, causing the bottom drilling bit to tilt at an angle. The inventors discovered that because the diameter of the top of the down-the-hole hammer drill bit is much smaller than the diameter of the drill bit, the annular gap between the diameter of the top of the down-the-hole hammer drill bit and the diameter of the borehole is increased. The larger this gap is, the greater the tilt angle of the drill bit during drilling, making it easier for the borehole to deviate and affecting drilling quality.

[0004] During drilling, borehole verticality is a crucial technical indicator. To ensure borehole verticality during down-the-hole (DH) hammer drilling, the only solution is to reduce drill pressure (DPP). This reduces drill pipe flexibility, decreases the lateral force (P) at the top of the DHPP, and ensures that the centerline of the DHPP's top aligns as closely as possible with the borehole centerline. Achieving this requires a significant reduction in DPP, which in turn drastically decreases drilling speed, impacting drilling progress and extending the construction period.

[0005] In addition, the inventors also discovered that the lateral force P generated at the top of the down-the-hole hammer rod can easily cause the drill rod to bend, which in turn causes the drill hole to collapse by hitting the hole wall, increasing the probability of accidents inside the hole. Moreover, once there is a collapse inside the hole that generates resistance, the down-the-hole hammer rod is not easy to pull out. Summary of the Invention

[0006] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a down-the-hole hammer drill bit that increases drilling efficiency, makes the borehole straighter, and reduces the probability of accidents in the borehole.

[0007] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0008] A down-the-hole hammer drill bit includes an outer sleeve with at least two support members inside. Adjacent support members are spaced apart. Each support member has an opening. The multiple support members support a down-the-hole hammer rod and an inner sleeve connected to the down-the-hole hammer rod through the openings. A connector is provided at the end of the inner sleeve furthest from the down-the-hole hammer rod for connection to the drill rod. The down-the-hole hammer drill bit of the down-the-hole hammer rod protrudes from one end of the outer sleeve. A bevel is provided at the other end of the outer sleeve to facilitate the removal of stuck parts within the borehole during rotation of the outer sleeve. A reduced-diameter section is provided at the end of the inner sleeve furthest from the down-the-hole hammer rod, connected to the connector. A flange is circumferentially provided on the reduced-diameter section for connection to the same support member.

[0009] As described above, in a down-the-hole hammer drill bit, the connector is a tapered head that can be inserted into one end of the drill rod. The maximum outer diameter of the tapered head is smaller than the outer diameter of the reduced-diameter section. The tapered head and the drill rod are detachably connected. The tapered head and the reduced-diameter section are an integral structure. The reduced-diameter section is set through the opening of the support member. The tapered head is set to facilitate the connection between the inner sleeve and the drill rod.

[0010] As described above, in a down-the-hole hammer drill bit, the tapered head is provided with a first external thread in the circumferential direction to connect with one end of the drill rod through a threaded structure. The threaded structure facilitates the on-site installation of the tapered head and the drill rod.

[0011] Alternatively, in some designs, the tapered head engages with a recess at one end of the drill pipe.

[0012] As described above, in a down-the-hole hammer drill bit, considering on-site installation, one end of the inner sleeve connected to the down-the-hole hammer rod body is detachably connected to the down-the-hole hammer rod body.

[0013] As described above, in a down-the-hole hammer drill bit, the inner sleeve is provided with an internal thread on the inner side of the end connected to the down-the-hole hammer rod body. The end of the down-the-hole hammer rod body connected to the inner sleeve has a double-layer structure. In the double-layer structure, the inner layer wall is provided with a second external thread that mates with the internal thread in the circumferential direction. The inner layer wall and the outer layer wall in the double-layer structure are spaced apart by a set distance to accommodate one end of the inner sleeve. The double-layer structure ensures a reliable connection between the down-the-hole hammer rod body and the inner sleeve, and also ensures the perpendicularity of the connection between the inner sleeve and the down-the-hole hammer rod body.

[0014] In the down-the-hole hammer drill bit described above, the diameter of the outer sleeve is smaller than the diameter of the down-the-hole hammer drill bit, so as to avoid interference between the outer sleeve and the borehole wall;

[0015] Considering the overall structural strength, the diameter of the outer sleeve is 15-30mm smaller than the diameter of the down-the-hole hammer drill bit. This reduces the annular gap at the top of the down-the-hole drill bit and greatly reduces the tilt angle of the down-the-hole hammer drill bit.

[0016] As described above, in a down-the-hole hammer drill bit, the oblique cut depth of the outer sleeve is 150-300mm to meet the requirement of catching the broken pieces of the borehole wall during drilling.

[0017] The outer sleeve is 5-8m long, and the inner sleeve is matched with the length of the outer sleeve. This increases the overall length of the down-the-hole hammer drill bit to 5-8m, further extending the angle change of the drill top of the down-the-hole hammer rod to the drill bit at the bottom of the well. This greatly reduces the deflection angle of the drill bit during drilling and ensures the verticality of the borehole during pressurized drilling.

[0018] As described above, in a down-the-hole hammer drill bit, the outer diameter of the flange is larger than the outer diameter of the down-the-hole hammer rod, and the flange is specifically welded to the reduced-diameter section of the inner sleeve.

[0019] As described above, a down-the-hole hammer drill bit has two support components: a first support plate and a second support plate. The first support plate supports the reduced-diameter section, and the second support plate supports the down-the-hole hammer rod. The inner diameter of the opening in the first support plate is larger than the inner diameter of the opening in the second support plate.

[0020] Secondly, the present invention also provides a method for operating a down-the-hole hammer drill bit, comprising the following:

[0021] The inner sleeve passes through the opening of the inner support member of the outer sleeve, and the reduced diameter section at one end of the inner sleeve passes through the opening of the support member and a flange is fitted on the reduced diameter section.

[0022] The down-the-hole hammer rod passes through the opening in the support of the outer sleeve and connects to the other end of the inner sleeve.

[0023] The locking element passes through the flange and part of the support to achieve a tight connection between the inner sleeve and the outer sleeve;

[0024] The connector at one end of the inner sleeve is connected to the drill pipe;

[0025] By manipulating the drill rod, the down-the-hole hammer rod body drives the down-the-hole hammer drill bit to drill a hole;

[0026] After setting the drilling depth, pull the drill rod upwards. If resistance is encountered, rotate the drill rod and rotate the outer sleeve cut to remove the stuck part inside the borehole.

[0027] The beneficial effects of the present invention are as follows:

[0028] 1) This invention extends the length of the down-the-hole hammer drill bit through the inner sleeve, while the outer sleeve supports the inner sleeve and the down-the-hole hammer rod, ensuring the support strength of the down-the-hole hammer drill bit. At the same time, it effectively increases the annular gap between the top diameter of the down-the-hole hammer drill bit and the inner diameter of the borehole. When the drill pressure applied by the drill rod is applied to the top of the down-the-hole hammer drill bit, even if the top of the down-the-hole hammer drill bit is subjected to a lateral force P due to the flexibility of the drill rod, the inclination angle is greatly reduced due to the reduction of the annular gap. Furthermore, due to the increase in the overall length of the down-the-hole hammer drill bit, the angle change at the top is extended to the drill bit drilling at the bottom of the well, which greatly reduces the deflection angle of the down-the-hole hammer drill bit during drilling. This ensures the verticality of the borehole during pressurized drilling, and there is no need to reduce the drill pressure, thus fully ensuring the construction progress.

[0029] 2) Through the overall structure design, this invention can effectively prevent drill rod bending and reduce the probability of accidents in the hole while ensuring the verticality of the borehole during drilling. Moreover, even if there is resistance during the lifting process due to collapse, the oblique cut can be rotated by rotating the down-the-hole hammer drill bit, making it easier to remove the stuck parts in the borehole.

[0030] 3) By setting the inner sleeve and outer sleeve, the present invention can extend the drilling down-the-hole hammer drill bit to 5 to 8 meters and increase the diameter of the top of the down-the-hole hammer rod body, reducing the annular gap between it and the well wall to about 10 mm, which fully ensures the verticality of the borehole during pressurized drilling and can achieve a good drilling verticality effect.

[0031] 4) In this invention, one end of the inner sleeve is detachably connected to the down-the-hole hammer rod body, which facilitates on-site installation. The other end of the inner sleeve is provided with a reduced diameter section, which facilitates the inner sleeve passing through the opening of the support member. The other end of the reduced diameter section is provided with a connector to facilitate detachable connection with the drill rod. Attached Figure Description

[0032] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0033] Figure 1 This is a schematic diagram of a down-the-hole hammer drill tool in the prior art.

[0034] Figure 2 This is a schematic diagram of a down-the-hole hammer drill according to one or more embodiments of the present invention.

[0035] Figure 3 This is a schematic diagram of the inner sleeve in a down-the-hole hammer drill according to one or more embodiments of the present invention.

[0036] Figure 4 This is the present invention. Figure 3 Schematic diagram of the AA section.

[0037] Figure 5 This is a schematic diagram of the outer sleeve in a down-the-hole hammer drill according to one or more embodiments of the present invention.

[0038] Figure 6 This is a schematic diagram of the outer sleeve of a down-the-hole hammer drill bit according to one or more embodiments of the present invention, after being cut open by 1 / 4.

[0039] Figure 7 This is a schematic diagram of the usage state of a down-the-hole hammer drill according to one or more embodiments of the present invention.

[0040] The diagram exaggerates the spacing or dimensions between parts to show their positions; the diagram is for illustrative purposes only.

[0041] The components are: 1. oblique cut, 2. connector, 3. first support plate, 4. flange, 5. inner sleeve, 6. outer sleeve, 7. down-the-hole hammer rod body, 8. second support plate, 9. down-the-hole hammer drill bit, 10. drill rod, 11. reduced diameter section, 12. inner sleeve body. Detailed Implementation

[0042] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0043] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, unless otherwise expressly indicated by the invention, the singular form is also intended to include the plural form. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0044] As described in the background section, existing technologies suffer from the problem of large tilt angles in down-the-hole hammer drill bits. To address this technical problem, this invention proposes a down-the-hole hammer drill bit.

[0045] Example 1

[0046] In a typical embodiment of the present invention, reference is made to Figure 2As shown, a down-the-hole hammer drill bit includes an outer sleeve 6, with at least two support members disposed inside the outer sleeve 6. The support members are spaced apart and have openings. The multiple support members support the down-the-hole hammer rod 7 and the inner sleeve 5 connected to the down-the-hole hammer rod 7 through the openings. The end of the inner sleeve 5 away from the down-the-hole hammer rod 7 is provided with a connector 2 for connection to the drill rod 10. The down-the-hole hammer drill bit 9 of the down-the-hole hammer rod 7 protrudes from one end of the outer sleeve. The other end of the outer sleeve 6 is provided with a beveled cut 1 to facilitate the removal of the stuck part in the borehole during the rotation of the outer sleeve 6. The end of the inner sleeve 5 away from the down-the-hole hammer rod 7 is provided with a reduced diameter section 11, which is connected to the connector 2. The reduced diameter section 11 is provided with a flange 4 circumferentially connected to the same support member.

[0047] The inner sleeve 5, when the formation dip angle increases and the formation hardness changes significantly during drilling, making it easier for the well to deviate, ensures the verticality of the newly drilled borehole by guiding and constraining the down-the-hole hammer drill bit that is drilling ahead, thanks to the inner sleeve 5.

[0048] In this embodiment, reference Figure 3 and Figure 4 As shown, the inner sleeve 5 includes an inner sleeve body 12. One end of the inner sleeve body 12 is provided with a reduced diameter section 11. The length of the reduced diameter section 11 is less than the length of the inner sleeve body 12. The connector 2 is a tapered head that can be inserted into one end of the drill rod 10. The maximum outer diameter of the tapered head is less than the outer diameter of the reduced diameter section 11. The tapered head and the drill rod 10 are detachably connected. The tapered head and the reduced diameter section 11 are an integral structure. The reduced diameter section 11 is provided through the opening of the support member. The tapered head facilitates the connection between the inner sleeve 5 and the drill rod 10.

[0049] The tapered head is provided with a first external thread in the circumference to connect with one end of the drill rod 10 through a threaded structure. The threaded structure facilitates the on-site installation of the tapered head and the drill rod 10.

[0050] Alternatively, in other examples, the conical head engages with a recess at one end of the drill pipe 10, the shape of which is adapted to the conical head to ensure reliable engagement between the drill pipe and the conical head.

[0051] Considering the on-site installation, it is understandable that the end of the inner sleeve 5 connected to the down-the-hole hammer rod 7 is detachably connected to the down-the-hole hammer rod 7.

[0052] Specifically, the inner sleeve 5 is connected to the down-the-hole hammer rod 7 at one end with a cylindrical hole on the inner side, and an internal thread is provided at the cylindrical hole. The end of the down-the-hole hammer rod 7 connected to the inner sleeve 5 has a double-layer structure. In the double-layer structure, the inner layer wall is provided with a second external thread that mates with the internal thread in the circumferential direction. A groove is formed between the inner layer wall and the outer layer wall in the double-layer structure. That is, the inner layer wall and the outer layer wall are spaced at a certain distance to accommodate one end of the inner sleeve 5. The double-layer structure ensures a reliable connection between the down-the-hole hammer rod 7 and the inner sleeve 5, and also ensures the perpendicularity of the connection between the inner sleeve 5 and the down-the-hole hammer rod 7.

[0053] In addition, the diameter of the outer sleeve 6 is smaller than the diameter of the down-the-hole hammer drill bit 9 to avoid interference between the outer sleeve and the borehole wall;

[0054] Considering the overall structural strength, the diameter of the outer sleeve 6 is 15-30mm smaller than the diameter of the down-the-hole hammer drill bit 9, specifically 20mm. This reduces the annular gap at the top of the down-the-hole drill bit to 10mm, thereby greatly reducing the tilt angle of the down-the-hole hammer drill bit 9.

[0055] refer to Figure 5 and Figure 6 As shown, one end of the outer sleeve 6 is flat, and a bevel 1 is provided on the top side of the outer sleeve 6, that is, the side near the conical head. The depth of the bevel 1 is 150-300mm, specifically 200mm, to meet the needs of receiving the broken pieces of the borehole wall during drilling. The bevel 1 is provided so that if resistance is encountered during the drilling process, the bevel 1 can be rotated by rotating the down-the-hole drill bit, making it easier to remove the stuck parts in the hole.

[0056] Understandably, the length of the outer sleeve 6 is 5-8m, and the length of the inner sleeve 5 is matched with the length of the outer sleeve 5. This increases the overall length of the down-the-hole hammer drill bit to 5-8m. The length of the down-the-hole hammer rod 7 is usually 1.2-1.5m, so the length of the inner sleeve 6 is 3.8-6.5m. This further extends the angle change of the top of the down-the-hole hammer rod to the down-the-hole hammer drill bit 9 drilling at the bottom of the well, greatly reducing the deflection angle of the down-the-hole hammer drill bit 9 during drilling and ensuring the verticality of the borehole during pressurized drilling.

[0057] Understandably, the outer diameter of the flange 4 is larger than the outer diameter of the down-the-hole hammer rod 7. The flange 4 is specifically welded to the reduced diameter section 11 of the inner sleeve. The reduced diameter section 11 passes through the support opening. After the down-the-hole hammer rod 7 and the down-the-hole hammer drill bit 9 are installed, the flange 4 is welded and fixed to the reduced diameter section 11 of the inner sleeve.

[0058] In this embodiment, there are two support components: a first support plate 3 and a second support plate 8. The first support plate 3 and the second support plate 8 are specifically steel plates. Both the first support plate 3 and the second support plate 8 are welded and fixed to the inner side of the outer sleeve 6. Both the first support plate 3 and the second support plate 8 are annular. In use, the first support plate 3 is on top and the second support plate 8 is on the bottom. The first support plate 3 supports the reduced diameter section 11, and the second support plate 8 supports the down-the-hole hammer rod body 7. The second support plate 8 and the down-the-hole hammer rod body 7 are clearance-fitted on the side near the down-the-hole hammer drill bit 9. The inner diameter of the opening in the first support plate 3 is larger than the inner diameter of the opening in the second support plate 8.

[0059] It is easy to understand that the inner diameter of the first support plate 3 is larger than the outer diameter of the reduced diameter section 11, but smaller than the outer diameter of the inner sleeve body 12. That is, the step between the inner sleeve body 12 and the reduced diameter section 11 serves as a limiting function. The first support plate 3 has threaded screw holes machined around the opening to facilitate the connection of fasteners such as bolts through the flange 4 and the first support plate 3. This makes the inner sleeve 5, the outer sleeve 6 and the downhole hammer rod body 7 form a rigid whole.

[0060] The down-the-hole hammer drill bit provided in this embodiment is referenced. Figure 7 As shown, the inner sleeve 5 extends the length of the down-the-hole hammer drill bit, and the outer sleeve 6 supports the inner sleeve 5 and the down-the-hole hammer rod 7, forming a strong rigid connection between the down-the-hole hammer rod 7 and the drill bit. This ensures the support strength of the down-the-hole hammer drill bit and effectively increases the annular gap between the top diameter of the down-the-hole hammer drill bit and the inner diameter of the borehole. When the drill pressure applied by the drill rod is applied to the top of the down-the-hole hammer drill bit, even if the top of the down-the-hole hammer drill bit is subjected to a lateral force P due to the flexibility of the drill rod, the reduction in the annular gap greatly reduces the inclination angle. Furthermore, due to the increase in the overall length of the down-the-hole hammer drill bit, the angle change at the top extends to the drill bit drilling at the bottom of the well, greatly reducing the deflection angle of the down-the-hole hammer drill bit 9 during drilling. This ensures the verticality of the borehole during pressurized drilling without reducing the drill pressure, thus fully guaranteeing the construction strength.

[0061] Moreover, the overall structure design ensures the verticality of the borehole during drilling while reducing the probability of accidents inside the borehole. Even if a collapse occurs and resistance is generated during the lifting process, the oblique cut 1 can be rotated by rotating the down-the-hole hammer drill bit, making it easier to remove the stuck parts inside the borehole, thus ensuring the success of subsequent drilling.

[0062] In addition, after the down-the-hole hammer drill bit in this embodiment is assembled and the drilling operation is completed, it can be disassembled or not disassembled during relocation and can be transported directly for future use.

[0063] Example 2

[0064] This embodiment provides a working method for a down-the-hole hammer drill bit, including the following:

[0065] The inner sleeve 5 passes through multiple support plate openings inside the outer sleeve 6. The reduced diameter section 11 at one end of the inner sleeve 5 passes through multiple support plate openings and reaches the top of the outer sleeve 6, which is close to the oblique cut 1. A flange 4 is fitted on the reduced diameter section 11.

[0066] The down-the-hole hammer rod 7 passes through the second support plate 8 of the outer sleeve 6 and is connected to the other end of the inner sleeve 5. The down-the-hole hammer drill bit 9 is set at the end of the down-the-hole hammer rod 7 exposed outside the outer sleeve. After the longitudinal distance between the down-the-hole hammer drill bit 9 and the outer sleeve 6 is adjusted to the working distance between the up and down of the down-the-hole hammer drill bit, it is generally 48-55mm. The flange 4 is moved and fixed at the inner sleeve diameter reduction section 11.

[0067] Locking components, such as bolts, pass through the flange 4 and the first support plate 3 to achieve a tight connection between the inner sleeve 5 and the outer sleeve 6;

[0068] The connector 2 at one end of the inner sleeve 5 is connected to the drill rod 10;

[0069] By manipulating the drill rod 10, the down-hole hammer drill bit 9 is driven by the down-hole hammer rod body 7 to perform drilling.

[0070] After setting the drilling depth, pull the drill rod 10 upwards. If resistance is encountered, rotate the drill rod 10 and rotate the oblique cut 1 of the outer sleeve to remove the stuck part in the borehole.

[0071] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A down-the-hole hammer drill bit, characterized in that, The device includes an outer sleeve, with at least two support members inside the outer sleeve. The support members are spaced apart and have openings. The multiple support members support the down-the-hole hammer rod body and the inner sleeve connected to the down-the-hole hammer rod body through the openings. The end of the inner sleeve away from the down-the-hole hammer rod body is provided with a connector to connect with the drill rod. The down-the-hole hammer drill bit of the down-the-hole hammer rod body protrudes from one end of the outer sleeve. The other end of the outer sleeve is provided with a bevel to facilitate the removal of the stuck parts in the borehole during the rotation of the outer sleeve. The end of the inner sleeve away from the down-the-hole hammer rod body is provided with a reduced diameter section, which is connected to the connector. The reduced diameter section is provided with a flange around its circumference to connect with the same support member. The diameter of the outer sleeve is smaller than the diameter of the down-the-hole hammer drill bit; The outer sleeve is 5-8m long, and the inner sleeve is adapted to the length of the outer sleeve.

2. The down-the-hole hammer drill bit according to claim 1, characterized in that, The connector is a tapered head that can be inserted into one end of the drill rod. The maximum outer diameter of the tapered head is smaller than the outer diameter of the reduced diameter section. The tapered head and the drill rod are detachably connected, and the tapered head and the reduced diameter section are an integral structure.

3. A down-the-hole hammer drill bit according to claim 2, characterized in that, The tapered head is provided with a first external thread in the circumferential direction to connect with one end of the drill rod through a threaded structure. Alternatively, the tapered head engages with a recess at one end of the drill pipe.

4. A down-the-hole hammer drill bit according to claim 1, characterized in that, One end of the inner sleeve that connects to the downhole hammer rod body is detachably connected to the downhole hammer rod body.

5. A down-the-hole hammer drill bit according to claim 4, characterized in that, The inner sleeve is provided with an internal thread on the inner side of the end where it connects to the downhole hammer rod body. The end where the downhole hammer rod body connects to the inner sleeve is a double-layer structure. In the double-layer structure, the inner layer wall is provided with a second external thread that mates with the internal thread in the circumferential direction. The inner layer wall and the outer layer wall are spaced apart by a set distance to accommodate one end of the inner sleeve.

6. A down-the-hole hammer drill bit according to claim 1, characterized in that, The diameter of the outer sleeve is 15-30 mm smaller than the diameter of the down-the-hole hammer drill bit.

7. A down-the-hole hammer drill bit according to claim 1, characterized in that, The oblique cut depth of the outer sleeve is 150-300mm to meet the requirement of catching the broken pieces of the borehole wall during drilling.

8. A down-the-hole hammer drill bit according to claim 1, characterized in that, The outer diameter of the flange is larger than the outer diameter of the downhole hammer rod.

9. A down-the-hole hammer drill bit according to claim 1, characterized in that, The support is provided in two places, namely a first support plate and a second support plate. The first support plate supports the reduced diameter section, and the second support plate supports the downhole hammer rod. The inner diameter of the opening in the first support plate is larger than the inner diameter of the opening in the second support plate.

10. A method for operating a down-the-hole hammer drill according to any one of claims 1-9, characterized in that, Includes the following: The inner sleeve passes through the opening of the inner support member of the outer sleeve, and the reduced diameter section at one end of the inner sleeve passes through the opening of the support member and a flange is fitted on the reduced diameter section. The down-the-hole hammer rod passes through the opening in the support of the outer sleeve and connects to the other end of the inner sleeve. The locking element passes through the flange and part of the support to achieve a tight connection between the inner sleeve and the outer sleeve; The connector at one end of the inner sleeve is connected to the drill pipe; By manipulating the drill rod, the down-the-hole hammer rod body drives the down-the-hole hammer drill bit to drill a hole; After setting the drilling depth, pull the drill rod upwards. If resistance is encountered, rotate the drill rod and rotate the outer sleeve cut to remove the stuck part inside the borehole.

Images