A variable diameter pyramid type drilling powder discharge and pressure relief device

Abstract

The present invention discloses a variable diameter pyramid type drilling powder discharge pressure relief device, which belongs to the field of drilling pressure relief in coal mining or metal mining. It includes a pressure relief connecting rod and a powder discharge pressure relief drill bit, the powder discharge pressure relief drill bit is installed at the front end of the pressure relief connecting rod, and the rear end of the pressure relief connecting rod is connected to the drill rod. The powder discharge pressure relief drill bit includes a crushing exhaust pick part, a detachable pick part and a spiral powder discharge end cover part connected in sequence from front to back; the crushing exhaust pick part includes a crushing exhaust pick main body, and the crushing exhaust pick main body is respectively provided with axial crushing teeth, radial pick one and air guide holes, and the detachable pick part is formed by connecting a plurality of groups of detachable pick monomers in sequence, and the pick monomers are arranged in a triangular prism shape for the convenience of powder discharge, and the spiral powder discharge end cover part includes a spiral powder discharge end cover main body, and a spiral powder discharge groove and an air inlet hole are arranged on the spiral powder discharge end cover main body. The present invention can realize rapid powder discharge and rapid drilling in the target area during drilling under the action of high-pressure gas.

Description

Technical Field

[0001] The invention relates to the field of variable-diameter pyramid-shaped drilling pressure relief in coal mining or metal mining, and in particular to a drilling dust removal pressure relief device. Background Art

[0002] Compared with shallow mining, the stress environment of coal and rock mass in deep mining is more complex. Due to high stress, strong mining disturbance and complex geological structure, the frequency and intensity of rock burst are significantly increased. At present, the research on rock burst has achieved rich research results, but due to the "opacity" of the underground rock mass itself and the uncertainty of the stress environment in which it is located, rock burst is still a difficult problem faced by coal mine science and technology workers.

[0003] In response to the above problems, many scholars have made great progress in the current research on comprehensive prevention and control of rock burst, providing guarantee for safe coal mining. Drilling pressure relief technology is an effective local active solution for coal mine rock burst prevention and control. It can avoid high stress concentration and improve the medium properties of coal and rock to reduce the ability to accumulate elastic energy. The drilling pressure relief method in coal or rock mass is favored by coal mining enterprises because of its high efficiency, low cost and good pressure relief effect.

[0004] However, the existing pressure relief devices still have certain shortcomings in field use, mainly manifested in the insufficient rigidity and low stability of the drill bits in the pressure relief devices; the inability to discharge dust dryly, resulting in low dust discharge efficiency; and the single drill bit structure design cannot meet the needs of complex rock mass pressure relief. At the same time, the original drill bit connected to the forward-type fully automatic controllable variable diameter pressure relief connecting rod has a low effective dust discharge space and cannot achieve effective dry dust discharge. Therefore, the development of a pressure relief drill bit that can not only ensure dry dust discharge in the borehole but also address the complex and variable rock mass structure has become an urgent problem to be solved at this stage.

[0005] The main research reports on the existing technologies are:

[0006] CN204060516U discloses a dry internal powder discharge drill bit, which mainly uses the powder discharge holes on the drill bit body to discharge dry powder. The drill bit body of the device is cylindrical. In the rock body, the drill bit body is parallel to the rock wall and cannot form an effective powder discharge space. Therefore, the powder discharge efficiency of the drill bit is low. At the same time, the drill bit cannot be used in a forward-type fully automatic controllable variable diameter pressure relief connecting rod.

[0007] CN108979549B discloses a dry internal powder discharge drill bit, which mainly adopts spiral cutting blades and through holes to discharge dry powder. The end of the drill bit cannot meet the needs of rock crushing, which will cause large pieces of rock to block the drill hole, making it only suitable for drilling in soft rock. At the same time, the spiral cutting blade has low strength, resulting in poor stability of the drill bit.

[0008] In summary, the test device in the prior art has not yet achieved the problem of changing the drill bit structure for complex rock masses, nor has it solved the problems of rapid powder removal and rapid drilling. Therefore, relevant researchers in this field are committed to developing a variable-diameter pyramid-type drilling powder removal and pressure relief device. Summary of the invention

[0009] The purpose of the present invention is to provide a variable diameter pyramid-type drilling powder removal and pressure relief device, which can achieve rapid powder removal and rapid drilling in the target area during the drilling process under the action of high-pressure gas; according to different rock mass environments, the device further selectively changes its own structure in combination with the tensile strength of the coal mass or rock mass, thereby accelerating the rapid powder removal and drilling of the pressure relief borehole.

[0010] In order to achieve the above-mentioned purpose, the technical problem to be solved by the present invention is to provide a drill bit that can drill quickly and discharge powder quickly.

[0011] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0012] A variable diameter pyramid type drilling powder discharge pressure relief device, comprising a pressure relief connecting rod and a powder discharge pressure relief drill bit, wherein the powder discharge pressure relief drill bit is installed at the front end of the pressure relief connecting rod, and the rear end of the pressure relief connecting rod is connected to the drill rod required in the drilling process, and the powder discharge pressure relief drill bit comprises a crushing exhaust tooth part, a detachable tooth part and a spiral powder discharge end cover part which are sequentially connected from front to back;

[0013] The crushing exhaust pick portion includes a crushing exhaust pick body, on which an axial crushing tooth, a radial pick one and an air guide hole are respectively arranged, wherein the radial pick one is distributed on the periphery of the crushing exhaust pick body in a triangular prism shape, the axial crushing tooth is located at the front end of the crushing exhaust pick body, and the air guide hole is located at the center of the crushing exhaust pick body;

[0014] The detachable pick part is formed by connecting a plurality of groups of detachable pick monomers in sequence, wherein each group of detachable pick monomers comprises a detachable pick body, on which a radial pick second is arranged, the radial pick second is in the form of a triangular prism and distributed on the periphery of the detachable pick body, and an exhaust hole is arranged on the detachable pick body;

[0015] The spiral powder discharge end cover portion includes a spiral powder discharge end cover body, on which a spiral powder discharge groove and an air inlet are arranged. The spiral powder discharge groove is formed by steel sheets arranged in a counterclockwise spiral. The air inlet is located at the center of the spiral powder discharge end cover body. A thread is arranged at the end of the spiral powder discharge end cover body, which is connected to the pressure relief connecting rod through the thread.

[0016] As a preferred solution of the present invention, the pressure relief connecting rod comprises a pressure relief connecting rod body, an expanding cutting head, a fixed cutting head, a supporting expanding rod, a sliding connecting wedge, a trigger piston, a spring, a sliding fixed plate and a stopper;

[0017] The pressure relief connecting rod body is cylindrical as a whole, and two grooves are arranged on the pressure relief connecting rod body as a connecting wedge track and a fixed plate track respectively, the sliding fixed plate is located in the fixed plate track, and the sliding connecting wedge is located in the connecting wedge track, and both can slide relatively in their respective tracks; a water / gas connecting pipe and a piston cavity are arranged inside the pressure relief connecting rod body, the piston cavity is located in the center of the pressure relief connecting rod body, and the water / gas connecting pipe is located on both sides of the pressure relief connecting rod body, and a plurality of limiting holes are evenly arranged above the fixed plate track, and the connecting wedge track is connected with the piston cavity;

[0018] A group of the enlarged diameter cutting heads, a group of the supporting enlarged diameter rods and a group of the fixed rods are symmetrically arranged on both sides of the pressure relief connecting rod body, wherein the front end of each enlarged diameter cutting head is movably connected to the sliding fixed plate, the rear end is movably connected to the front end of the fixed cutting head on the same side, and the tail end of the fixed cutting head on the same side is movably connected to the pressure relief connecting rod body;

[0019] The front end of each supporting expansion rod is movably connected to the fixed cutter head on the same side thereof, and the rear end thereof is movably connected to the sliding connection wedge. The sliding connection wedge is tightly attached to one side of the trigger piston. The trigger piston is located in the piston cavity and is connected to the spring. The limiter is arranged in the limit hole.

[0020] As another preferred embodiment of the present invention, the detachable pick units are provided in 3 to 6 groups, threads are provided at the ends of the detachable pick bodies, and adjacent detachable pick units are connected by threads.

[0021] Further preferably, the material of the radial pick 1 and the radial pick 2 are both cemented carbide, and the material of the steel sheet is also cemented carbide.

[0022] Further preferably, the crushing and exhausting pick portion, the detachable pick portion and the spiral powder discharge end cover portion are sequentially connected together by threads.

[0023] Furthermore, the maximum diameter of the crushing and exhausting pick body is 90 mm, the minimum diameter of the detachable pick body is 100 mm, the maximum diameter of the detachable pick body is 150 mm, and the maximum outer diameter of the spiral powder discharge groove is 135 mm.

[0024] Furthermore, the angle between adjacent radial pick teeth 1 is 120°, and the angle between adjacent radial pick teeth 2 is 120°.

[0025] Compared with the prior art, the present invention brings the following beneficial technical effects:

[0026] The present invention proposes a variable diameter pyramid-type drilling powder discharge and pressure relief device, in which a powder discharge and pressure relief drill bit is adopted. The powder discharge and pressure relief drill bit is improved, and the main improvement points are: it comprises a crushing and exhausting pick part, a detachable pick part and a spiral powder discharge end cover part which are sequentially connected from front to back, wherein the crushing and exhausting pick part is arranged at the front end of the drill bit body, and the crushing and exhausting pick part comprises a crushing and exhausting pick body, on which axial crushing teeth, radial pick one and air guide holes are respectively arranged, and the axial crushing teeth and radial pick one cooperate with each other to crush the rock to a high degree and in a triangular prism shape. The radial pick 1 is more conducive to rock crushing and improves the drilling speed; the removable pick part is connected by multiple groups of removable pick monomers, the specific number of which is determined by the physical and mechanical properties of the coal or rock mass, and mainly depends on the tensile strength of the rock mass. Each group of removable pick monomers includes a removable pick body, on which a radial pick 2 is arranged. The radial pick 2 is distributed in the form of a triangular prism on the periphery of the removable pick body. The design and distribution of the radial pick 2 have a high degree of rock crushing, and the specific number of removable pick monomers can be reasonably selected according to the tensile strength of the rock. Combined with the spiral powder discharge end cover, rapid powder discharge can be achieved.

[0027] The present invention can realize dust removal in the whole process of drilling, so that drilling debris can be effectively discharged from the drill hole, thus preventing the occurrence of drill hole blockage and improving construction efficiency.

[0028] The invention has a high degree of rock crushing, which prevents large rock masses from hindering the drilling of the drill bit and improves the drilling speed.

[0029] The invention aims at rock masses of different lithologies, reasonably selects the number of picks according to the tensile strength of the rock, quantitatively controls the construction parameters, and has strong adaptability to complex geomechanical environments.

[0030] The present invention can achieve perfect docking with the forward-type fully automatic controllable variable-diameter pressure relief connecting rod, and assist in completing the local pressure relief of the coal body or rock body. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The present invention will be further described below in conjunction with the accompanying drawings:

[0032] Figure 1 It is a schematic structural diagram of a variable diameter pyramid-shaped drilling dust removal and pressure relief device of the present invention;

[0033] Figure 2A three-dimensional diagram of a dust removal and pressure relief drill bit according to the present invention;

[0034] Figure 3 A plan view of a dust removal and pressure relief drill bit according to the present invention;

[0035] Figure 4 It is a plan view of a detachable pick unit of the present invention;

[0036] Figure 5 It is an assembly diagram of multiple groups of detachable pick units of the present invention;

[0037] Figure 6 It is a plan view of the spiral powder discharge end cover of the present invention;

[0038] In the figure:

[0039] 1-powder discharge and pressure relief drill bit; 2-pressure relief connecting rod; 11-crushing and exhaust pick portion; 12-detachable pick portion; 13-spiral powder discharge end cover portion; 111-axial crushing tooth; 112-radial pick one; 113-air guide hole; 121-radial pick two; 122-thread; 123-exhaust hole; 131-spiral powder discharge groove; 132-connecting thread; 133-air inlet hole. DETAILED DESCRIPTION

[0040] The present invention proposes a variable diameter pyramid-shaped drilling powder removal and pressure relief device. In order to make the advantages and technical solutions of the present invention clearer and more specific, the present invention is described in detail below in conjunction with specific embodiments.

[0041] like Figure 1 As shown, the present invention is a variable diameter pyramid-type drilling powder removal and pressure relief device, which mainly includes a pressure relief connecting rod 2 and a powder removal and pressure relief drill bit 1. The powder removal and pressure relief drill bit 1 is installed at the front end of the pressure relief connecting rod 2. When in actual use, the drill rod required in the drilling process is connected to the rear end of the pressure relief connecting rod 2.

[0042] The pressure relief connecting rod 2 used in the present invention adopts the pressure relief connecting rod with the same structure as that in the application number 2019110514381, including a pressure relief connecting rod body, an expanding cutting head, a fixed cutting head, a supporting expanding rod, a sliding connecting wedge, a trigger piston, a spring, a sliding fixed plate and a limiter; the pressure relief connecting rod body is cylindrical as a whole, and two grooves are arranged on the pressure relief connecting rod body as a connecting wedge track and a fixed plate track respectively, the sliding fixed plate is located in the fixed plate track, and the sliding connecting wedge is located in the connecting wedge track, and both can slide relative to each other in their respective tracks; a water / gas connecting pipe and a piston cavity are arranged inside the pressure relief connecting rod body, the piston cavity is located in the center of the pressure relief connecting rod body, and the water / gas connecting pipe is located on both sides of the pressure relief connecting rod body, and a plurality of limit holes are evenly arranged above the fixed plate track, and the connecting wedge track is connected to the piston cavity;

[0043] A group of enlarged diameter cutting heads, a group of supporting enlarged diameter rods and a group of fixed rods are symmetrically arranged on both sides of the pressure relief connecting rod body, wherein the front end of each enlarged diameter cutting head is movably connected to the sliding fixed plate, the rear end is movably connected to the front end of the fixed cutting head on the same side, and the tail end of the fixed cutting head on the same side is movably connected to the pressure relief connecting rod body;

[0044] The front end of each supporting expansion rod is movably connected to the fixed cutter head on the same side thereof, and the rear end thereof is movably connected to the sliding connection wedge. The sliding connection wedge is tightly attached to one side of the trigger piston. The trigger piston is located in the piston cavity and is connected to the spring. The limiter is arranged in the limit hole.

[0045] Combination Figure 2 and Figure 3 As shown, the main innovation of the present invention is to improve the dust removal and pressure relief drill bit 1, and its specific structure includes a crushing and exhausting pick part 11, a detachable pick part 12 and a spiral dust removal end cover part 13, wherein the crushing and exhausting pick part 11 is located at the front end of the device, and the detachable pick part 12 is connected to the tail end of the crushing and exhausting pick part 11 by threading. The specific threaded connection method is to set an external thread at the tail end of the crushing and exhausting pick part, and set an internal thread at the end of the detachable pick part, and the two are butted and connected together by matching the external thread and the internal thread. The spiral dust removal end cover part 13 is located at the tail end of the detachable pick part 12, and the two are also connected together by threading.

[0046] The crushing exhaust pick portion comprises a crushing exhaust pick body, which is a hollow cylinder, on which an axial crushing tooth 111, a radial pick 112 and an air guide hole 113 are respectively arranged, wherein three radial picks 1 are arranged, which are evenly distributed on the periphery of the crushing exhaust pick body, and the angle between adjacent radial picks is preferably 120 degrees, and the three radial picks 112 are distributed on the periphery of the crushing exhaust pick body in the form of triangular prisms, the axial crushing tooth 111 is located at the front end of the crushing exhaust pick body, and the air guide hole 113 is located at the center of the crushing exhaust pick body, and the function of the axial crushing tooth 111 is to crush the rock directly in front of the drill bit, so as to facilitate the drill bit to drill on a fixed track, and the radial pick 1 is arranged in a triangular prism shape, which presents the characteristics of hollow distribution compared with the previous drill bit structure, and has the function of providing a large amount of movement space for crushing rock mass, so as to facilitate the discharge of crushed rock mass or rock powder;

[0047] The function of the air guide hole is to provide high-pressure gas at the front end of the drill bit to discharge the broken rock or rock powder inside the crushing exhaust pick 11 and the detachable pick 12 to the spiral powder discharge end cover 13, so as to facilitate the rapid discharge of the broken rock or rock powder.

[0048] Combination Figure 4 and Figure 5As shown, the detachable pick portion is formed by a plurality of groups of detachable pick units connected in sequence. The specific number of detachable pick units is determined by the physical and mechanical properties of the coal or rock mass, and mainly depends on the tensile strength of the rock mass. For example, 3 to 6 detachable pick units are preferably used, and adjacent detachable pick units are connected by threads 122.

[0049] Each group of removable pick units includes a removable pick body, which is a hollow cylinder. A radial pick 2 121 is arranged on the removable pick body. The radial pick 2 121 is in the form of a triangular prism and is distributed on the periphery of the removable pick body. The function of the radial pick 2 is to crush the rock in the radial direction of the drill bit, so that the drill bit can expand and advance in the surrounding rock. Compared with the existing drill bit, the advantage of this structural design of this part is that it can not only ensure dry and rapid powder discharge in the borehole, but also achieve pressure relief for complex rock masses. The structure of the drill bit is changeable: an exhaust hole 123 is arranged on the removable pick body. The function of the exhaust hole 123 is to provide high-pressure gas in the radial area of ​​the drill bit to discharge the crushed rock or rock powder to the spiral powder discharge end cover 13, so as to facilitate the rapid discharge of the crushed rock or rock powder.

[0050] like Figure 6 As shown, the spiral powder discharge end cover portion includes a spiral powder discharge end cover body, on which a spiral powder discharge groove 131 and an air inlet 133 are arranged. The spiral powder discharge groove 131 is formed by spirally arranging steel sheets in a counterclockwise direction. The advantage of such a structural design of the spiral powder discharge groove 131 is that a guide groove is provided for crushing rock or rock powder, thereby avoiding accumulation and blockage of powder along the way and realizing rapid powder discharge.

[0051] The air inlet hole is located at the center of the spiral powder discharge end cover body. A connecting thread 132 is provided at the end of the spiral powder discharge end cover body, and is connected to the above-mentioned pressure relief connecting rod through the connecting thread 132.

[0052] Preferably, the maximum diameter of the crushing and exhausting pick body is 90 mm, the minimum diameter of the detachable pick body is 100 mm, the maximum diameter of the detachable pick body is 150 mm, and the maximum outer diameter of the spiral powder discharge groove is 135 mm.

[0053] In the present invention, it is further preferred that the angle between adjacent radial picks 1 is 120°, the angle between adjacent radial picks 2 is 120°, and the width of the radial pick 2 121 is 40 mm.

[0054] The following is a detailed description of the method for using the variable diameter pyramid type drilling dust removal and pressure relief device of the present invention.

[0055] The method for using the above-mentioned variable diameter pyramid-shaped drilling dust removal and pressure relief device specifically comprises the following steps:

[0056] a. Determination of the number of detachable pick units

[0057] The number of detachable pick units is determined based on the physical and mechanical properties of the rock mass to be decompressed:

[0058] When the tensile strength of the rock mass is ≤3MPa, the detachable pick portion uses 6 detachable pick monomers;

[0059] When the tensile strength of the rock mass is 3MPa<≤6MPa, the detachable pick portion uses 5 detachable pick monomers;

[0060] When the tensile strength of the rock mass is 6MPa<≤9MPa, the detachable pick portion uses four detachable pick monomers;

[0061] When the tensile strength of the rock mass is 9MPa<≤12MPa, the detachable pick portion uses three detachable pick monomers;

[0062] When the tensile strength of the rock mass is greater than 12MPa, the detachable pick portion uses two detachable pick monomers;

[0063] b. Determination of the target area for pressure relief: Based on the actual geological conditions of the coal mine, select the construction site where local pressure relief treatment is required, and determine that the distance from the pressure relief drill hole to the tunnel side or coal wall is 0.5 to 3 times the distance;

[0064] c. The selection of gas pressure is determined according to the angle between the borehole and the horizontal. When the angle between the borehole and the horizontal is between θ and 90°, the gas pressure is greater than 0.5MPa. When the angle between the borehole and the horizontal is between -90° and θ, the gas pressure is less than or equal to 0.5MPa.

[0065] d. On-site construction: At the construction site where local pressure relief treatment is carried out, the dust removal pressure relief drill bit and the pressure relief connecting rod are connected to the drilling rig through the drill pipe in sequence, and the drilling rig is turned on to drill towards the target area. After reaching the target area, the relevant equipment is slowly retracted using the drilling rig.

[0066] The preferred embodiments of the present invention are described in detail above with reference to the accompanying drawings; however, the present invention is not limited thereto.

[0067] Although this article uses more terms such as powder removal and pressure relief drill bit, pressure relief connecting rod, crushing and exhaust tooth part, and detachable tooth part, it does not exclude the possibility of using other terms. These terms are used only to more conveniently describe and explain the essence of the present invention; interpreting them as any additional limitations is contrary to the spirit of the present invention.

[0068] It should be further noted that the specific embodiments described herein are merely examples of the spirit of the present invention. A person skilled in the art of the present invention may make various modifications or additions to the specific embodiments described or replace them in a similar manner, but this will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

Claims

1. A variable diameter pyramid type drilling dust removal and pressure relief device, comprising a pressure relief connecting rod and a dust removal and pressure relief drill bit, wherein the dust removal and pressure relief drill bit is installed at the front end of the pressure relief connecting rod, and the rear end of the pressure relief connecting rod is connected to the drill rod required in the drilling process, characterized in that: The powder discharge and pressure relief drill bit comprises a crushing and exhausting pick portion, a detachable pick portion and a spiral powder discharge end cover portion which are sequentially connected from front to back; The crushing exhaust pick portion includes a crushing exhaust pick body, on which an axial crushing tooth, a radial pick one and an air guide hole are respectively arranged, wherein the radial pick one is distributed on the periphery of the crushing exhaust pick body in a triangular prism shape, the axial crushing tooth is located at the front end of the crushing exhaust pick body, and the air guide hole is located at the center of the crushing exhaust pick body; The detachable pick part is formed by connecting a plurality of groups of detachable pick monomers in sequence, wherein each group of detachable pick monomers comprises a detachable pick body, on which a radial pick second is arranged, the radial pick second is in the form of a triangular prism and distributed on the periphery of the detachable pick body, and an exhaust hole is arranged on the detachable pick body; The spiral powder discharge end cover part comprises a spiral powder discharge end cover body, on which a spiral powder discharge groove and an air inlet are arranged, the spiral powder discharge groove is formed by spirally arranging steel sheets arranged counterclockwise, the air inlet is located at the center of the spiral powder discharge end cover body, and a thread is arranged at the end of the spiral powder discharge end cover body, which is connected to the pressure relief connecting rod through the thread; The pressure relief connecting rod comprises a pressure relief connecting rod body, an expanding cutting head, a fixed cutting head, a supporting expanding rod, a sliding connecting wedge, a trigger piston, a spring, a sliding fixing plate and a stopper; The pressure relief connecting rod body is cylindrical as a whole, and two grooves are arranged on the pressure relief connecting rod body as a connecting wedge track and a fixed plate track respectively, the sliding fixed plate is located in the fixed plate track, and the sliding connecting wedge is located in the connecting wedge track, and both can slide relatively in their respective tracks; a water / gas connecting pipe and a piston cavity are arranged inside the pressure relief connecting rod body, the piston cavity is located in the center of the pressure relief connecting rod body, the water / gas connecting pipe is located on both sides of the pressure relief connecting rod body, and a plurality of limiting holes are evenly arranged above the fixed plate track, and the connecting wedge track is connected with the piston cavity; A group of the enlarged diameter cutting heads, a group of the supporting enlarged diameter rods and a group of the fixed cutter heads are symmetrically arranged on both sides of the pressure relief connecting rod body, wherein the front end of each enlarged diameter cutting head is movably connected to the sliding fixed plate, the rear end is movably connected to the front end of the fixed cutter head on the same side, and the tail end of the fixed cutter head on the same side is movably connected to the pressure relief connecting rod body; The front end of each supporting expansion rod is movably connected to the fixed cutter head on the same side thereof, and the rear end thereof is movably connected to the sliding connection wedge, the sliding connection wedge is tightly attached to one side of the trigger piston, the trigger piston is located in the piston cavity and connected to the spring, and the limiter is arranged in the limit hole; The maximum diameter of the crushing exhaust pick body is 90 mm, the minimum diameter of the detachable pick body is 100 mm, the maximum diameter of the detachable pick body is 150 mm, and the maximum outer diameter of the spiral powder discharge groove is 135 mm.

2. The variable diameter pyramid type drilling dust removal and pressure relief device according to claim 1, characterized in that: The detachable pick units are provided in 3 to 6 groups, and threads are provided at the ends of the detachable pick bodies, and adjacent detachable pick units are connected by threads.

3. The variable diameter pyramid type drilling dust removal and pressure relief device according to claim 2, characterized in that: The material of the radial pick 1 and the radial pick 2 are both cemented carbide, and the material of the steel sheet is also cemented carbide.

4. The variable diameter pyramid type drilling dust removal and pressure relief device according to claim 2, characterized in that: The crushing exhaust pick part, the detachable pick part and the spiral powder discharge end cover part are sequentially connected together through threads.

5. The variable diameter pyramid type drilling dust removal and pressure relief device according to claim 2, characterized in that: The included angle between adjacent radial pick teeth 1 is 120°, and the included angle between adjacent radial pick teeth 2 is 120°.

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