Anti-mud packing structure of down-the-hole drill bit

Abstract

The present application relates to a kind of down-the-hole drill bit anti-mud structure, including impactor and drill bit, the drill bit is equipped with chip flute, gas outlet passage, multiple drill teeth, the drill bit inside slidingly connected with slider, the slider is equipped with multiple blocks, the end of multiple blocks The slider is also equipped with rod-shaped piece, the rod-shaped piece is inserted into gas outlet passage, the inner wall of the gas outlet passage is equipped with avoiding slot, one end of the rod-shaped piece inserted into gas outlet passage is equipped with first connector, the impactor is equipped with second connector, the first connector passes through avoiding slot and is connected with second connector.The present application can effectively prevent soft mud and other impurities adhere drill bit, so as to reduce the probability of mud pack phenomenon when drill bit drilling.

Description

Technical Field

[0001] This invention relates to the field of drill bits, and in particular to an anti-mud-packing structure for down-the-hole drill bits. Background Technology

[0002] Down-the-hole (DH) drills are used in mining, engineering construction, and other fields. The DH drill bit is mounted on an impactor. The piston rod inside the impactor can reciprocate in the extension direction of the drill rod, applying a predetermined impact force to the drill bit, causing it to generate a downward impact force and forcing the drill bit forward to break the rock strata.

[0003] When drilling, drill cuttings and other impurities tend to adhere to the drill bit, filling the gaps between the drill teeth and forming a mud layer. The formation of a mud layer can reduce the mechanical drilling speed, or even cause the drill bit to become a cylindrical mud head, making it stuck during the drilling process. Summary of the Invention

[0004] This application provides a mud-packing anti-mud structure for down-the-hole drill bits, which can effectively prevent impurities such as soft mud from adhering to the drill bit, thereby reducing the probability of mud packing during drilling.

[0005] The anti-mud-packing structure for down-the-hole drill bits provided in this application adopts the following technical solution:

[0006] A mud-packing anti-mud structure for a down-the-hole drill bit includes an impactor and a drill bit. The drill bit is provided with a chip removal groove, an air outlet channel, and multiple drill teeth. A slider is slidably connected inside the drill bit, and the slider is provided with multiple top blocks, the ends of which extend out of the drill bit. The slider is also provided with a rod-shaped member that extends into the air outlet channel. An clearance groove is formed on the inner wall of the air outlet channel. A first connector is provided on the end of the rod-shaped member that extends into the air outlet channel. The impactor is provided with a second connector, and the first connector passes through the clearance groove and is connected to the second connector.

[0007] By adopting the above technical solution, during down-the-hole drilling, the piston rod inside the impactor strikes the drill bit, propelling it forward. Components such as the slide block, connected to the impactor, do not move with the drill bit. As the drill bit advances, multiple top blocks retract into the drill bit, preventing them from impacting the rock wall and protecting them. After the drill bit stops advancing, the rock drill or other equipment pushes the impactor forward, moving it towards the drill bit. As the impactor moves forward, it drives the slide block forward. As the slide block advances, multiple top blocks extend out of the drill bit, pushing away drill cuttings and other impurities adhering to the drill bit surface, preventing mud buildup. The extension of the top blocks also compresses drill cuttings at the drill bit's tip towards the periphery, making it easier for these impurities to be discharged through the chip removal groove under high-pressure airflow, reducing drill cuttings residue at the front of the drill bit. This allows the drill bit's impact force to be better transmitted to the rock wall, improving drilling efficiency. At the same time, the reduction in drill cuttings also reduces the probability of drill bit mud buildup.

[0008] Preferably, the rod-shaped component includes a rod body one and a rod body two sleeved on the rod body one, the rod body one being connected to the slider, and the first connecting member being disposed on the rod body two.

[0009] By adopting the above technical solution, the second rod has a larger volume, which allows for a larger connection point with the first connector, making the connection between the two more secure.

[0010] Preferably, the first connector includes a connecting rod fixed to the second rod body, the axis of the connecting rod being perpendicular to and intersecting the axis of the second rod body, and the end of the connecting rod away from the second rod body extending into the clearance groove; the second connector includes a bolt, the bolt being threaded onto the connecting rod.

[0011] By adopting the above technical solution, the connection between the rod body and the impactor can be firmly completed.

[0012] Preferably, the impactor has a countersunk hole that faces the clearance groove. The bolt is inserted into the countersunk hole, and the bolt's thread extends into the impactor and is threadedly connected to the connecting rod.

[0013] By adopting the above technical solution, when the drill bit is installed inside the impactor and the drill bit and the impactor are against each other, the countersunk hole is aligned with the clearance groove, which facilitates the connection of the bolt and the connecting rod and makes the assembly of the two easier.

[0014] Preferably, the outer wall of the top block is provided with multiple air passages 1, the interior of the top block is provided with air passages 2, and the multiple air passages 1 are all connected to air passages 2; the slider is provided with air passages 3, the multiple air passages 2 on the top blocks are all connected to air passages 3, the rod body 1 is provided with air passages 4 that connect to air passages 3, and the rod body 2 is provided with an air injection mechanism, which is used to inject air into air passages 4.

[0015] By adopting the above technical solution, multiple top blocks extend from the drill bit, squeezing the drill cuttings at the drill bit's tip towards the periphery of the drill bit. The air injection mechanism then injects gas into air passage four. The gas flows through air passage four into air passage three, then through air passage three into multiple air passages two, and finally is ejected from multiple air passages one. The gas ejected from air passage one blows away the drill cuttings adhering to the drill bit surface, cleaning the drill bit's surface. Simultaneously, the drill cuttings are blown towards the periphery of the drill bit, directing them to the vicinity of the chip removal area, making it easier for the drill cuttings to be discharged through the chip removal grooves.

[0016] Preferably, the air injection mechanism includes an air groove on the second rod, a piston head slidably connected in the air groove, and a one-way valve on the second rod. The first rod is connected to the piston head, and the air groove is connected to the fourth air passage. The one-way valve is connected to the air groove and the air outlet passage. The one-way valve only allows air to enter the air groove from the air outlet passage. The stroke of the slider is less than the stroke of the impactor. During the forward movement of the drill bit, it contacts the slider and drives the slider to move away from the impactor. When the drill bit moves to contact the slider, the outlets of the multiple first air passages are all located inside the drill bit.

[0017] By adopting the above technical solution, when the drill bit advances, the slider first slides inside the drill bit, causing multiple top blocks to retract into the drill bit. During this process, the slider moves to a point where it comes into contact with the drill bit. At this time, the outlets of multiple air passages 1, which are connected to the outside, move into the drill bit, effectively preventing drill cuttings from blocking the outlets of air passages 1 when the drill bit strikes the rock. As the drill bit continues to advance, it drives the slider and rod 1 to move away from rod 2. When rod 1 moves away from rod 2, it pulls the piston head to slide in the air groove, thereby drawing outside air into the air groove through a one-way valve. After the drill bit stops advancing, the rock drill and other equipment will push the impactor forward, moving the impactor toward the drill bit. When the impactor moves forward, it will bring rod 2 closer to the drill bit. When rod 2 moves closer to the drill bit, it will compress the gas in the air groove. However, since the outlets of multiple air passages 1 are all located inside the drill bit, the gas in the air groove cannot be discharged. In the initial stage of the movement of rod two, rod two moves together with the piston head, rod one, slider, and multiple top blocks, causing the multiple top blocks to extend out of the drill bit, and causing multiple air passages one to move out of the drill bit. After the air passages one move out of the drill bit, the air in the air grooves is forced out from multiple air passages one under the compression of rod two. The air forced out from multiple air passages one forms multiple airflows to wash away the drill cuttings on the surface of the drill bit. Because the air discharge speed in the air grooves is limited, while the movement speed of the impactor is relatively fast, the air in the air grooves cannot be emptied quickly. Therefore, the pressure of rod two on the air in the air grooves is converted into a force that pushes the slider to slide, causing the slider to move closer and closer to the sealing block. The continuous movement of the slider closer and closer to the sealing block causes the top block to extend out of the sealing block. Thus, the airflow ejected from multiple air passages one follows the movement of the top blocks to wash different areas of the drill bit, creating the effect of pushing away and washing away drill cuttings during the movement of multiple top blocks. Subsequently, when the slider moves to the point of contact with the sealing block, the slider stops moving. However, the slider's stroke is shorter than the impactor's stroke. Therefore, the impactor continues to move, carrying rod two closer to the drill bit. As rod two moves closer to the drill bit, it continues to force air out of the air channels from the air grooves. At this point, because the slider cannot move, the force exerted by rod two on the air cannot be converted into a force that propels the slider. Therefore, the pressure generated by rod two on the gas in the air grooves is greater, resulting in a stronger impact force from the airflow in the air channels. This allows the drill cuttings to be more effectively blown towards the periphery of the drill bit, enabling them to be effectively removed through the chip removal grooves.

[0018] Preferably, the drill bit has an installation groove, and the slider is slidably connected in the installation groove; the drill bit has a sealing block, which is used to seal the opening of the installation groove, and multiple top blocks pass through the sealing block and extend out of the drill bit; in the initial state, the slider abuts against the sealing block, and the outlets of multiple air passages are exposed outside the sealing block, and there is a movement space between the slider and the bottom wall of the installation groove; when the drill bit moves forward and the slider moves to abut against the bottom wall of the installation groove, the outlets of multiple air passages are contained in the sealing block.

[0019] By adopting the above technical solution, the installation of components such as sliders can be facilitated.

[0020] Preferably, the air passage is inclined, and the outlet of the air passage that connects to the outside faces the drill bit.

[0021] By adopting the above technical solution, the airflow compressed from the air passage can more effectively flush the surface of the drill bit, and by utilizing the shape of the drill bit, the drill cuttings can be more effectively blown to the periphery of the drill bit.

[0022] The main technical effects of this invention are reflected in the following aspects:

[0023] 1. This invention, by setting and controlling the movement of multiple top blocks, enables the drill bit to effectively remove drill cuttings and other impurities adhering to the surface of the drill bit after drilling, thereby preventing impurities from adhering to the surface of the drill bit and thus preventing the occurrence of mud packing.

[0024] 2. This invention, by setting up an air passage structure, enables high-pressure airflow to flush the surface of the drill bit and blow away drill cuttings, further preventing the formation of mud pockets.

[0025] 3. The present invention enables the rod body to be firmly connected to the impactor through the cooperation of bolts and connecting rods. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of a down-the-hole drill.

[0027] Figure 2 This is a schematic diagram of the drill bit's structure.

[0028] Figure 3 yes Figure 1 A cross-sectional view of a down-the-hole drill along line AA.

[0029] Figure 4 yes Figure 3 A magnified view of a section at point B.

[0030] Figure 5 yes Figure 3 A magnified view of a section at point C.

[0031] Figure 6 yes Figure 3 A schematic diagram showing the structure of the piston rod inside the impactor impacting the drill bit, and the drill bit advancing to contact the slider.

[0032] Figure 7 yes Figure 6 A magnified view of a section at point D.

[0033] Figure 8 This is a schematic diagram of the drill bit moving forward with the slider, rod, and piston head.

[0034] Figure 9 yes Figure 8 A magnified view of a section at point E in the middle.

[0035] Figure 10 This is a schematic diagram of the impactor's structure as it moves forward and approaches the drill bit.

[0036] Figure 11 yes Figure 10 A magnified view of a section at point F.

[0037] Reference numerals: 1. Impactor; 11. Countersunk hole; 2. Drill bit; 21. Chip removal groove; 22. Air outlet channel; 23. Drill teeth; 24. Clearance groove; 25. Mounting groove; 26. Sealing block; 3. Sliding block; 31. Air passage three; 4. Top block; 41. Air passage one; 42. Air passage two; 5. Rod-shaped component; 51. Rod body one; 52. Rod body two; 53. Air passage four; 6. First connecting piece; 61. Connecting rod; 7. Second connecting piece; 71. Bolt; 8. Air injection mechanism; 81. Air groove; 82. Piston head; 83. One-way valve. Detailed Implementation

[0038] The present invention will be further described in detail below with reference to the accompanying drawings, so that the technical solution of this application can be more easily understood and mastered.

[0039] Reference Figures 1-3 This embodiment of a down-the-hole drill bit 2 anti-mud-packing structure includes an impactor 1 and a drill bit 2. The drill bit 2 is provided with a chip removal groove 21, an air outlet channel 22, and multiple drill teeth 23. The drill bit 2 is provided with an installation groove 25 and a sealing block 26, which is used to seal the opening of the installation groove 25.

[0040] Reference Figure 3 and Figure 4 A slider 3 is slidably connected within the mounting groove 25 along the length of the drill bit 2. The stroke of the slider 3 is less than that of the impactor 1. Multiple top blocks 4 are fixed on the slider 3, all of which pass through the sealing block 26 and extend out of the drill bit 2. A rod-shaped member 5 is also provided on the end of the slider 3 away from the sealing block 26, extending into the air outlet channel 22. The rod-shaped member 5 includes a first rod body 51 and a second rod body 52 sleeved on the first rod body 51, wherein the first rod body 51 is connected to the slider 3.

[0041] Reference Figure 3 and Figure 5Two first connecting parts 6 are symmetrically arranged on the outer peripheral wall of the rod body 52. ​​The first connecting parts 6 are connecting rods 61. Two clearance grooves 24 are symmetrically opened on the side wall of the air outlet channel 22. The two connecting rods 61 extend into the two clearance grooves 24 respectively. The impactor 1 has two countersunk holes 11 symmetrically opened. The two countersunk holes 11 are directly opposite the two clearance grooves 24. A second connecting part 7 is inserted into and rotatably connected to each of the two countersunk holes 11. The second connecting part 7 is a bolt 71. The screw of the two bolts 71 extends into the impactor 1 and is threadedly connected to the two connecting rods 61 respectively.

[0042] Reference Figure 3 and Figure 4 Each top block 4 has multiple air passages 41 on its outer wall, distributed circumferentially on the top block 4. Each top block 4 also has an air passage 42 inside, with each of the air passages 41 connected to it. The slider 3 has an air passage 31 inside, with each of the air passages 42 on the top blocks 4 connected to it. The rod body 51 has an air passage 53 connected to the air passage 31. The air passages 41 are angled, and the outlet of each air passage 41 facing the outside faces the drill bit 2.

[0043] Reference Figure 3 The rod body 52 is equipped with an air injection mechanism 8, which is used to inject air into the air passage 53. The air injection mechanism 8 includes an air groove 81 formed on the rod body 52, a piston head 82 slidably connected in the air groove 81, and a one-way valve 83 provided on the rod body 52. ​​The rod body 51 extends into the air groove 81 and connects with the piston head 82. The air groove 81 connects to the air passage 53. The one-way valve 83 connects the air groove 81 and the air outlet passage 22. The one-way valve 83 only allows air to enter the air groove 81 from the air outlet passage 22.

[0044] The down-the-hole drilling process of this application is as follows:

[0045] Reference Figure 3 and Figure 4 When the drill bit 2 is not activated, the impactor 1 is in contact with the drill bit 2, the slider 3 is in contact with the sealing block 26, and the outlets of multiple air passages 41 are exposed outside the sealing block 26. There is a space for movement between the slider 3 and the bottom wall of the mounting groove 25. When the down-the-hole drill is working, the piston rod inside the impactor 1 will strike the drill bit 2 to advance the drill bit 2.

[0046] Reference Figure 6 and Figure 7 As the drill bit 2 advances, the bottom wall of the mounting groove 25 moves closer to the slider 3, while multiple top blocks 4 retract into the sealing block 26. Subsequently, the bottom wall of the mounting groove 25 moves to contact the slider 3. At this time, the outlets of multiple air passages 41 that connect to the outside are located inside the sealing block 26, effectively preventing drill cuttings from blocking the outlets of air passages 41 when the drill bit 2 strikes the rock.

[0047] Reference Figure 8 and Figure 9 The drill bit 2 continues to move forward and pushes the slider 3 away from the impactor 1. When the slider 3 moves away from the impactor 1, it will move the rod 1 51 away from the rod 2 52. When the rod 1 51 moves away from the rod 2 52, it will pull the piston head 82 to slide in the air groove 81, thereby drawing outside air into the air groove 81 through the one-way valve 83.

[0048] Reference Figure 10 and Figure 11 Once the kinetic energy of drill bit 2 is lost, it will stop moving. Then, the rock drill and other equipment will push the impactor 1 forward, moving it toward drill bit 2. As the impactor 1 moves forward, it will bring rod 2 52 closer to drill bit 2. When rod 2 52 moves closer to drill bit 2, it will compress the gas in air groove 81. However, since the outlets of multiple air passages 41 are all located inside drill bit 2, the gas in air groove 81 cannot be discharged. Therefore, in the initial stage of the movement of rod 2 52, rod 2 52 moves together with piston head 82, rod 1 51, slider 3, and multiple top blocks 4, causing the multiple top blocks 4 to extend and extend the sealing block 26.

[0049] Reference Figure 10 and Figure 11 When the multiple top blocks 4 extend the sealing block 26, they push away drill cuttings and other impurities adhering to the surface of the drill bit 2, preventing impurities from adhering to the surface of the drill bit 2 and thus preventing mud packing. When the multiple top blocks 4 extend the drill bit 2, they also squeeze the drill cuttings at the front end of the drill bit 2 towards the periphery of the drill bit 2, making it easier for drill cuttings and other impurities to be discharged through the chip removal groove 21 under the push of the high-pressure airflow, reducing the amount of drill cuttings remaining at the front of the drill bit 2. This allows the impact force of the drill bit 2 to be better transmitted to the rock wall, improving the drilling efficiency of the drill bit 2. At the same time, the reduction in drill cuttings also fundamentally reduces the probability of mud packing on the drill bit 2.

[0050] Reference Figure 10 and Figure 11 When the multiple top blocks 4 extend the sealing block 26, multiple air passages 41 will move out of the sealing block 26. After the air passages 41 move out of the sealing block 26, the air in the air groove 81 is squeezed out by the rod body 52 and the air squeezed out from the multiple air passages 41 will form multiple airflows to wash the drill cuttings on the surface of the drill bit 2.

[0051] Reference Figure 10 and Figure 11Because the air discharge speed in the air groove 81 is limited, while the impactor 1 moves relatively fast, the air in the air groove 81 cannot be quickly emptied. Therefore, the pressure of the rod 52 on the air in the air groove 81 is converted into a force that pushes the slider 3 to slide, causing the slider 3 to continuously move closer to the sealing block 26. This continuous movement of the slider 3 towards the sealing block 26 causes the top block 4 to move and extend beyond the sealing block 26. Consequently, the airflow ejected from the multiple air channels 41 follows the movement of the top block 4, scouring different areas of the drill bit 2. During the movement of the multiple top blocks 4, the effect of simultaneously pushing away and scouring drill cuttings is achieved.

[0052] Reference Figure 10 and Figure 11 When the slider 3 moves to contact the blocking block 26, the slider 3 stops moving. However, the stroke of the slider 3 is less than the stroke of the impactor 1. Therefore, the impactor 1 will continue to move with the rod 52 closer to the drill bit 2. When the rod 52 continues to move closer to the drill bit 2, it will continue to force the air in the air groove 81 out from the multiple air passages 41.

[0053] Reference Figure 10 and Figure 11 Because slider 3 cannot move, the force of the air compressed by rod 2 52 cannot be converted into the force that pushes slider 3 to move. Therefore, the pressure generated by rod 2 52 on the gas in air groove 81 will be greater when it moves. As a result, the airflow compressed from air passage 1 41 will have a greater impact force, thus more effectively blowing drill cuttings to the periphery of drill bit 2, allowing the drill cuttings to be effectively discharged through chip removal groove 21. When the impactor 1 moves to contact with drill bit 2, one drilling cycle of drill bit 2 ends, and the next drilling cycle will begin immediately.

[0054] Of course, the above are just typical examples of this application. In addition, this application may have many other specific implementation methods. All technical solutions formed by equivalent substitution or equivalent transformation fall within the scope of protection claimed in this application.

Claims

1. A bit anti-ballast structure, comprising a hammer (1) and a bit (2), the bit (2) is provided with a chip flute (21), an air outlet channel (22), and a plurality of drill teeth (23), characterized in that: The drill bit (2) is slidably connected with a sliding block (3), a plurality of jacks (4) are arranged on the sliding block (3), the ends of the plurality of jacks (4) extend out of the drill bit (2); a rod-shaped piece (5) is further arranged on the sliding block (3), the rod-shaped piece (5) extends into an air outlet channel (22); an avoiding groove (24) is arranged on the inner wall of the air outlet channel (22), a first connecting piece (6) is arranged on one end of the rod-shaped piece (5) extending into the air outlet channel (22), a second connecting piece (7) is arranged on the impactor (1), the first connecting piece (6) passes through the avoiding groove (24) and is connected with the second connecting piece (7); the rod-shaped piece (5) comprises a rod body one (51) and a rod body two (52) sleeved on the rod body one (51), the rod body one (51) is connected with the sliding block (3), and the first connecting piece (6) is arranged on the rod body two (52); a plurality of air passages one (41) are arranged on the outer wall of the jack (4), an air passage two (42) is arranged in the jack (4), and the plurality of air passages one (41) are in communication with the air passage two (42); an air passage three (31) is arranged in the sliding block (3), the air passage two (42) on the plurality of jacks (4) is in communication with the air passage three (31), and an air passage four (53) in communication with the air passage three (31) is arranged in the rod body one (51); an air injection mechanism (8) is arranged in the rod body two (52), and the air injection mechanism (8) is used for injecting air into the air passage four (53).

2. A bit anti-ballasting structure according to claim 1, characterized in that: The first connecting piece (6) comprises a connecting rod (61) fixed on the rod body two (52), the axis of the connecting rod (61) is perpendicular to and intersects with the axis of the rod body two (52), and one end of the connecting rod (61) away from the rod body two (52) extends into the avoiding groove (24); the second connecting piece (7) comprises a bolt (71), and the bolt (71) is threadedly connected on the connecting rod (61).

3. A bit anti-ballasting structure according to claim 2, characterized in that: The impactor (1) is provided with a countersunk hole (11), the countersunk hole (11) faces the avoiding groove (24), the bolt (71) is inserted into the countersunk hole (11), and the screw rod of the bolt (71) extends into the impactor (1) and is threadedly connected with the connecting rod (61).

4. The bit anti-ballasting structure of claim 1, wherein: The air injection mechanism (8) comprises an air groove (81) arranged on the rod body two (52), a piston head (82) slidably connected in the air groove (81), and a one-way valve (83) arranged on the rod body two (52), the rod body one (51) is connected with the piston head (82), and the air groove (81) is in communication with the air passage four (53); the one-way valve (83) is in communication with the air groove (81) and the air outlet channel (22), and the one-way valve (83) is only used for air to enter the air groove (81) from the air outlet channel (22); the movement stroke of the sliding block (3) is smaller than that of the impactor (1), the drill bit (2) is in contact with the sliding block (3) during the advancing process and drives the sliding block (3) to move away from the impactor (1), when the drill bit (2) moves to be in contact with the sliding block (3), the outlets of the plurality of air passages one (41) are located in the drill bit (2).

5. A bit anti-ballasting structure according to claim 4, characterized in that: The drill bit (2) is provided with a mounting groove (25), and the sliding block (3) is slidingly connected in the mounting groove (25); the drill bit (2) is provided with a blocking block (26), the blocking block (26) is used for blocking the slot opening of the mounting groove (25), a plurality of the top blocks (4) all pass through the blocking block (26) and extend out of the drill bit (2); in the initial state, the sliding block (3) abuts against the blocking block (26), the outlets of the plurality of the air passages (41) are all exposed outside the blocking block (26), and a movement space is left between the sliding block (3) and the bottom wall of the mounting groove (25); when the drill bit (2) advances and the sliding block (3) moves to abut against the bottom wall of the mounting groove (25), the outlets of the plurality of the air passages (41) are all accommodated in the blocking block (26).

6. A bit anti-ballasting structure according to claim 4, characterized in that: The air passage (41) is inclinedly arranged, and the outlet of the air passage (41) connected with the outside world faces the drill bit (2).

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