Airflow packer for reverse circulation drilling of large-diameter down-the-hole hammer and matched drilling tool

Abstract

The invention belongs to the technical field of geological drilling, and provides an airflow packer for reverse circulation drilling of a large-diameter down-the-hole hammer and a matched drilling tool, the airflow packer for reverse circulation drilling of the large-diameter down-the-hole hammer comprises a packing ring sleeve with a mounting hole in the center, and the outer side ring wall of the packing ring sleeve is provided with a packing contact protrusion extending outwards; the multiple packing contact protrusions are evenly distributed at intervals in the circumferential direction with the axis of the packing ring sleeve as the center. The airflow packer for reverse circulation drilling of the large-diameter down-the-hole hammer can be matched with the uneven wall face of the hole wall of a drill hole, the outer edge of the airflow packer tightly abuts against the hole wall of the drill hole, the airflow blocking and blocking effect is improved, it is guaranteed that circulation drilling work is stably and efficiently carried out, and the service life of the airflow packer is prolonged. Meanwhile, impact and friction between the outer edge of the airflow packer and the hole wall of the drill hole are reduced, abrasion of the airflow packer caused by the impact and friction is reduced, and the service life of the airflow packer is prolonged.

Description

Technical Field

[0001] The invention belongs to the technical field of geological drilling, and in particular relates to an air flow packer for reverse circulation drilling with a large-caliber down-the-hole hammer and a matching drilling tool. Background Art

[0002] Down-the-hole hammer drilling is a commonly used drilling process in rock formation drilling. Among them, pneumatic down-the-hole hammer drilling is particularly widely used. It uses the high-frequency energy impact generated by the down-the-hole hammer, combined with the rotary drive of the drilling rig and drill rod, to form continuous crushing of the rock, and uses high-pressure medium to achieve cooling of the drill bit and discharge of powder and cuttings. Since the ability to carry rock powder and cuttings to be discharged in the down-the-hole hammer drilling process mainly depends on the upward return speed of the air, that is, the upward return wind speed, when the outer annular space gap of the drilling well (the annular gap between the drill rod and the well wall) is too large, the upward return wind speed will be weakened, which will make it difficult for rock powder and cuttings to return, and the cuttings cannot be discharged in a timely and efficient manner. Especially for the drilling construction of large-diameter down-the-hole hammers (usually the borehole diameter is greater than or equal to 400mm), as the drilling depth becomes deeper and deeper, the required air pressure and supply air volume will become greater. In order to solve the above problems, the current down-the-hole hammer reverse circulation drilling process generally adopts a packer (plugger) to ensure the wind pressure at the bottom during the drilling process. However, the existing packers usually adopt a rubber sheet structure or a multi-layer rubber sheet structure to achieve the sealing and plugging of the airflow. On the one hand, since the borehole wall is not a smooth wall, it has an uneven rock wall. During the drilling process, the outer edge of the packer and the rock wall of the borehole collide and rub against each other, causing serious wear of the packer, resulting in a short service life of the packer, and the packer needs to be replaced frequently, affecting the drilling construction efficiency; on the other hand, the rubber sheet structure plugger is difficult to fit tightly with the uneven rock wall, resulting in poor plugging effect, especially after the outer edge of the packer is worn out after long-term use, resulting in a decrease in the sealing performance of the plugging, and it is very easy to have a poor seal and air leakage; in addition, during the drilling process, the upper part of the plugger is very likely to accumulate rock chips and rock powder. As the accumulation of powder chips increases, if it is not discharged in time, it is very easy to cause the drill to be stuck and buried, which seriously affects the normal progress of the drilling construction.

[0003] Therefore, it is necessary to design a large-caliber down-the-hole hammer reverse circulation drilling air flow packer and supporting drilling tools that can solve at least some of the above problems and defects. Summary of the invention

[0004] In order to solve the above technical problems, the present invention proposes an air flow packer for reverse circulation drilling with a large-diameter down-the-hole hammer, which can adapt to the uneven wall of the borehole, so that the outer edge of the air flow packer is in close contact with the borehole wall, thereby improving the air flow blocking effect and ensuring the stable and efficient circulation drilling work. At the same time, the impact and friction between the outer edge of the air flow packer and the borehole wall are reduced, thereby reducing the wear of the air flow packer caused thereby and extending the service life of the air flow packer.

[0005] The technical solution of the present invention is: The present invention proposes an air flow sealer for reverse circulation drilling of a large-caliber down-the-hole hammer, comprising a sealing ring sleeve with a mounting hole at the center, an outer ring wall of the sealing ring sleeve is provided with sealing contacts extending outward, a plurality of the sealing contacts are provided, and the sealing contacts are evenly spaced and distributed in a circumferential direction with the axis of the sealing ring sleeve as the center.

[0006] Preferably, the isolation contact spigot comprises a contact spigot base fixedly arranged on the outer ring wall of the isolation ring sleeve, a contact spigot head movably sleeved on the outer periphery of the contact spigot base, and a telescopic spring fixedly embedded in the contact spigot base; The end of the telescopic spring abuts against the contact protrusion head.

[0007] Preferably, the isolation ring sleeve is provided with a plurality of groups of isolation contacts at intervals along the axial direction thereof, and the isolation contacts in adjacent groups in the axial direction are axially cross-staggered.

[0008] Preferably, the outer ring wall of the isolation ring sleeve is further provided with elastic protrusions extending outward, and a plurality of the elastic protrusions are provided and are evenly spaced and distributed along the circumferential direction with the axis of the isolation ring sleeve as the center; The elastic contacts are located between adjacent isolation contact groups that are axially spaced apart.

[0009] Preferably, the sealing ring sleeve is further provided with at least one axially penetrating chip leakage hole, and a sealing plate movably arranged at the chip leakage hole; The sealing plate is movably arranged at the bottom of the isolation ring sleeve, so that the chip leakage hole can be opened and closed by turning over the sealing plate.

[0010] Preferably, a receiving groove adapted to the sealing plate is provided at the bottom of the sealing ring sleeve, and the sealing plate is movably embedded in the receiving groove through a hinge shaft; Both ends of the hinge shaft are sleeved with a flip torsion spring, one end of the flip torsion spring is fixedly connected to the sealing ring sleeve, and the other end is fixedly connected to the sealing baffle.

[0011] Preferably, the sealing ring sleeve is provided with a sealing bearing fixedly connected thereto, and the sealing bearing is located at the mounting hole.

[0012] Preferably, the present invention further provides a matching drilling tool for large-caliber down-the-hole hammer reverse circulation drilling, comprising a double-wall drill pipe, a forward and reverse joint and a down-the-hole hammer connected in sequence, and also comprising the above-mentioned large-caliber down-the-hole hammer reverse circulation drilling airflow packer; At least one airflow packer is provided, and its movable sleeve is arranged on the outer periphery of the double-wall drill pipe.

[0013] Preferably, the supporting drilling tool for reverse circulation drilling of a large-caliber down-the-hole hammer provided by the present invention further comprises a powder scooping tube fixedly sleeved on the outer periphery of the double-wall drill pipe, wherein the powder scooping tube is located above the airflow packer; The top of the powder scooping tube is provided with an oblique cut, and the outer edge of the oblique cut is provided with a cleaning ring protrusion fixedly arranged on the outer side wall of the powder scooping tube.

[0014] Preferably, the large-caliber down-the-hole hammer reverse circulation drilling supporting drilling tool provided by the present invention further comprises an airflow splitting sleeve fixedly sleeved on the forward and reverse joints and the outer periphery of the down-the-hole hammer, the top of the airflow splitting sleeve is fixedly connected to the forward and reverse joints, and the bottom thereof is provided with an opening; An annular frame plate arranged close to the opening is arranged inside the airflow diversion sleeve, and the annular frame plate is fixedly connected to the down-the-hole hammer.

[0015] Compared with the prior art, the present invention has the following advantages and effects: (1) A number of sealing contacts are arranged evenly and extended outward, so that the multiple sealing contacts on the outer edge of the airflow packer are in contact with the borehole wall. Compared with the surface contact of the outer edge of the traditional rubber sheet, the multiple sealing contacts adopt a more intensive multi-point contact, so that they can better fit and contact with the uneven rock wall, thereby improving the sealing and sealing effect between the airflow packer and the borehole wall; (2) A sealing contact including a contact head and a contact base that are movably connected is used. The contact head can be extended outward or compressed inward relative to the contact base, so as to better adapt to the uneven borehole rock wall, so that the sealing contact is closely attached to the borehole wall, thereby improving the sealing and barrier effect of the airflow packer. At the same time, since the contact head is a movable part, the collision and friction between the sealing contact and the borehole wall are effectively reduced, thereby reducing the wear of the sealing contact caused by this and extending the service life of the airflow packer; (3) Multiple groups of isolation contacts are arranged at intervals in the axial direction. Each group of isolation contacts is provided with a number of isolation contacts spaced apart in the circumferential direction, and the isolation contacts in adjacent groups are arranged in an axially cross-staggered manner to avoid air leakage and improve the blocking effect. In addition, elastic contacts can be arranged between adjacent isolation contact groups to further improve the sealing effect of the airflow sealer. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic structural diagram of an air flow packer for reverse circulation drilling with a large-caliber down-the-hole hammer in Example 1 of the present invention; Figure 2 It is a partial cross-sectional view of an air flow packer for reverse circulation drilling with a large-caliber down-the-hole hammer in Example 1 of the present invention; Figure 3 for Figure 2 A schematic diagram of the enlarged structure at position A in the middle; Figure 4 This is a schematic structural diagram of an air flow packer for reverse circulation drilling with a large-caliber down-the-hole hammer in Example 2 of the present invention; Figure 5 It is a front view of an air flow packer for reverse circulation drilling with a large-caliber down-the-hole hammer in Example 2 of the present invention; Figure 6 This is a schematic structural diagram of an air flow packer for reverse circulation drilling with a large-caliber down-the-hole hammer in Example 3 of the present invention; Figure 7 Another structural schematic diagram of the air flow packer for reverse circulation drilling of a large-caliber down-the-hole hammer in Example 3 of the present invention; Figure 8 This is a front view of an air flow packer for reverse circulation drilling with a large-caliber down-the-hole hammer in Example 3 of the present invention; Fig. 9 for Figure 8 Sectional view at the middle position BB; Fig.10 for Fig. 9 A schematic diagram of the enlarged structure at position C in the middle; Fig.11 This is a schematic diagram of the structure of a supporting drilling tool for reverse circulation drilling with a large-caliber down-the-hole hammer in Example 4 of the present invention; Fig.12 This is a schematic diagram of the structure of a powder scoop in a matching drill tool for reverse circulation drilling with a large-caliber down-the-hole hammer in Example 4 of the present invention; Fig.13 This is a schematic diagram of the structure of the airflow diversion sleeve in the supporting drilling tool for reverse circulation drilling of a large-diameter down-the-hole hammer in Example 4 of the present invention.

[0017] : 100, airflow seal; 110, sealing ring; 111, mounting hole; 112, sealing bearing; 120, sealing contact; 121, contact base; 122, contact head; 123, telescopic spring; 130, elastic contact; 140, chip leakage hole; 150, sealing plate; 160, hinged shaft; 170, flip torsion spring; 200, double-wall drill pipe; 300, positive and negative joints; 310, guide hole; 400, down-the-hole hammer; 500, powder bailing tube; 510, cleaning ring convex; 600, airflow diversion sleeve; 610, annular frame plate. DETAILED DESCRIPTION

[0018] In order to make those skilled in the art better understand the present invention, the present invention is further described in conjunction with specific embodiments. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0019] Embodiment 1: like Figure 1~Figure 3As shown, the present invention provides an air flow packer for reverse circulation drilling of a large-caliber down-the-hole hammer, which includes an isolation ring sleeve 110 with a mounting hole 111 at a central position, and a sealing bearing 112 fixedly connected to the isolation ring sleeve mounting hole 111 is provided, so that the isolation ring sleeve mounting sleeve is mounted on the outer periphery of the drill pipe, so that the isolation ring sleeve 110 can rotate relative to the drill pipe, thereby reducing the friction frequency between the outer edge of the air flow packer and the wall of the borehole, so as to reduce the wear of the outer edge of the air flow packer, thereby improving the service life of the air flow packer. It should be noted that the sealing bearing 112 is preferably a sealing bearing 112 with high sealing performance, such as a needle bearing, etc. In view of its mature technology in this field, its structure and principle are not repeated here.

[0020] Combination Figure 1 and Figure 2 As shown, the outer ring wall of the isolation ring 110 is provided with an outwardly extending isolation contact protrusion 120, and a plurality of isolation contact protrusions 120 are provided and are evenly spaced and distributed along the circumferential direction with the axis of the isolation ring 110 as the center. Figure 3 As shown, the isolation contact 120 includes a contact base 121 fixedly arranged on the outer ring wall of the isolation ring sleeve 110, a contact head 122 movably sleeved on the outer periphery of the contact base 121, and a telescopic spring 123 fixedly embedded in the contact base 121, wherein the terminal end of the telescopic spring 123 abuts against the contact head 122, so that the contact head 122 can perform telescopic movement relative to the contact base 121, thereby changing the overall extension length of the isolation contact 120 to adapt to the uneven borehole rock wall, so that the isolation contact 120 is closely attached to the borehole rock wall, thereby improving the sealing and blocking effects.

[0021] Furthermore, the end of the contact head 122 is in a smooth ball shape to reduce the friction and collision between the contact head 122 and the borehole wall, thereby reducing the wear of the contact head 122 caused thereby.

[0022] Specifically, since the borehole wall is not smooth and flat during the actual drilling process, it has unevenness. By setting a contact protrusion head 122 whose extension length can be telescopically changed, the isolation contact protrusion 120 can better abut and fit with the borehole wall, thereby playing a good airflow blocking role. Simply put, when the borehole wall protrudes outward, the hole wall abuts against the contact protrusion head 122, driving the contact protrusion head 122 to compress the telescopic spring 123 inward, and the overall extension length of the isolation contact protrusion 120 is reduced. The small size allows it to adapt to the protruding borehole wall. When the borehole wall is recessed, the hole wall and the contact protrusion head 122 are not in contact. The telescopic spring 123 drives the contact protrusion head 122 to extend outward under its own elastic force. The overall extension length of the isolation contact protrusion 120 is increased to make it adapt to the recessed borehole wall. Compared with the fixed outer diameter wind-blocking ring or wind-blocking disk in the existing isolation device, it has better airflow blocking effect and less damage to the isolation device, which effectively increases the overall service life of the isolation device.

[0023] Furthermore, the synaptic head 122 is movably and hermetically connected to the synaptic base 121, and both the synaptic base 121 and the synaptic head 122 are provided with a receiving cavity, and the telescopic spring 123 is telescopically arranged in the receiving cavity, one end of which is fixedly arranged in the receiving cavity of the synaptic base 121, and the other end extends into the receiving cavity of the synaptic head 122 and abuts against the synaptic head 122. Optionally, in some embodiments, the receiving cavity is filled with hydraulic oil, which plays a role of lubrication and sealing, so as to ensure that the synaptic head 122 can move smoothly and flexibly compared with the synaptic base 121.

[0024] Optionally, in some embodiments, the contact spout head 122 is an alloy head made of hard alloy, and the contact spout base 121 is a steel base made of high-strength steel; specifically, the contact spout head 122 can be made of hard alloy with good wear resistance such as YG3x, YG4c, etc., to increase its service life and reduce the wear caused by friction with the borehole wall. It should be noted that in order to reduce the manufacturing and use costs, the end of the contact spout head 122 can also be welded with alloy to ensure the service life of the contact spout head 122 while reducing the use and construction costs.

[0025] Embodiment 2: For Example 2 of the present invention, Figure 4 and Figure 5 Note that description of parts that are not different from those in Embodiment 1 will be omitted and will be given the same reference numerals.

[0026] like Figure 4 and Figure 5As shown, the present invention relates to an airflow sealer for reverse circulation drilling of a large-diameter down-the-hole hammer, wherein a sealing ring 110 is provided with a plurality of groups of sealing contacts 120 at intervals along its axial direction, and the sealing contacts 120 located in axially adjacent groups are axially cross-staggered and arranged to play a role in sealing and blocking the airflow, that is, the projection areas of the sealing contacts 120 in adjacent groups along the axial direction will not completely overlap.

[0027] Specifically, refer to Figure 5 As shown, in the present embodiment, two groups of isolation contacts 120 are provided, including a group near the top of the isolation ring 110 and a group near the bottom of the isolation ring 110. The isolation contacts 120 in the group near the top of the isolation ring 110 and the isolation contacts 120 in the group near the bottom of the isolation ring 110 are cross-staggered in the axial direction (in the direction of the axis of the isolation ring 110) to block the airflow.

[0028] The outer ring wall of the isolation ring 110 is also provided with an elastic contact 130 extending outward. There are several elastic contacts 130, which are evenly spaced and distributed along the circumferential direction with the axis of the isolation ring 110 as the center. The end of the elastic contact 130 is in a smooth ball head shape to reduce the friction between it and the borehole wall. The elastic contact 130 is specifically made of wear-resistant elastic material, for example, the elastic contact 130 can be made of butyl rubber or other rubber materials. The elastic contact 130 is located between adjacent isolation contact groups arranged axially at intervals, that is, the elastic contact group composed of multiple elastic contacts 130 is located between the axially adjacent isolation contact groups composed of multiple isolation contacts 120. Since the elastic contact 130 is more easily worn when it collides and rubs with the borehole wall than the isolation contact 120, the elastic contact 130 is arranged between the isolation contact 120 on both sides to reduce the wear caused by the collision and friction between it and the borehole wall.

[0029] Furthermore, the isolation ring sleeve 110 is provided with a plurality of groups of elastic contacts 130 at intervals along its axial direction. Specifically, in the present embodiment, two groups of elastic contacts 130 are provided at intervals along the axial direction of the isolation ring sleeve 110, and the two groups of elastic contacts 130 are both located between the two groups of isolation contacts 120 mentioned above, so as to further enhance the blocking function and effect on the airflow.

[0030] Optionally, in some embodiments, the extension length of the elastic contact protrusion 130 compared to the outer ring wall of the isolation ring sleeve 110 is between the maximum and minimum extension lengths of the isolation contact protrusion 120 compared to the outer ring wall of the isolation ring sleeve 110, so as to avoid wear and loss caused by the excessive extension length of the elastic contact protrusion 130 and poor sealing caused by the excessive extension length of the elastic contact protrusion 130.

[0031] Embodiment 3: For Example 3 of the present invention, Figure 6~Figure 10In addition, descriptions of parts that are not different from those in Embodiment 2 are omitted, and the same reference numerals are given.

[0032] like Figure 6~Figure 7 As shown, the present invention relates to an air flow packer for reverse circulation drilling of a large-caliber down-the-hole hammer, wherein the packing sleeve 110 is also provided with three axially penetrating chip leakage holes 140, and a baffle plate 150 movably arranged at the position of the chip leakage holes 140, the baffle plate 150 is movably arranged at the bottom of the packing sleeve 110, and the cross-sectional area of ​​the baffle plate 150 is adapted to the cross-sectional area of ​​the chip leakage holes 140, so that the chip leakage holes 140 can be opened and closed by turning over the baffle plate 150. In the actual drilling construction process, as the drilling depth gradually increases, rock cuttings and rock powder are continuously accumulated on the upper part of the air flow packer. When the rock cuttings and rock powder accumulate too much, if the accumulated powder is not discharged in time, it is very easy to cause drill jamming and drill burial accidents, affecting the normal progress of the drilling construction. Therefore, the present embodiment intermittently discharges the powder accumulated on the top of the air flow packer by providing the chip leakage holes 140 and the baffle plate 150, thereby avoiding the phenomenon of drill jamming and drill burial.

[0033] Combination Figure 8 and Fig. 9 As shown, the bottom of the sealing ring 110 is provided with a receiving groove adapted to the sealing plate 150, and the sealing plate 150 is movably embedded in the receiving groove through the hinge shaft 160. For details, refer to Fig.10 As shown, both ends of the hinge shaft 160 are sleeved with a flip torsion spring 170, one end of the flip torsion spring 170 is fixedly connected to the packing ring 110, and the other end is fixedly connected to the baffle plate 150. Specifically, the hinge shaft 160 is fixedly arranged in the receiving groove of the packing ring 110, and is perpendicular to the axis of the packing ring 110, and the baffle plate 150 is rotatably sleeved on the outer periphery of the hinge shaft 160. Under normal conditions, the baffle plate 150 is in a horizontal state blocked at the bottom of the chip leakage hole 140 under the action of the flip torsion spring 170. When too much rock cuttings and powder are accumulated on the top of the packing ring 110, the rock cuttings push the baffle plate 150 to flip and rotate, thereby opening the chip leakage hole 140, so that the rock cuttings accumulated on the top of the packing ring 110 are discharged downward through the chip leakage hole 140, thereby avoiding the problem of drill jamming caused by too much rock cuttings and powder accumulation on the top of the packing ring 110.

[0034] It should be noted that the opening and closing of the chip leakage hole 140 can also be achieved by means of an electric switch valve or an electronic switch (a pressure sensor can be provided) to achieve intermittent opening and chip removal and closing and sealing of the chip leakage hole 140, which should all fall within the protection scope of the present invention.

[0035] For further reference, Figure 7As shown, the sealing plate 150 includes two symmetrically arranged fan-shaped plates, and the sum of the cross-sectional areas of the two fan-shaped plates is compatible with the cross-sectional area of ​​the leakage hole 140. The two fan-shaped plates are movably embedded in the receiving groove at the bottom of the isolation ring sleeve 110 through the hinge shaft 160. By setting two symmetrically distributed fan-shaped plates, rock cuttings and powder are discharged downward through the joint of the two fan-shaped plates, thereby improving the rock cutting discharge efficiency. In addition, the flipping stroke of the two fan-shaped plates is smaller than that of a single independent sealing plate, thereby avoiding the phenomenon that the sealing plate 150 is blocked and the leakage hole 140 cannot be blocked.

[0036] Embodiment 4: For Example 4 of the present invention, Figure 11~Figure 13 Specifically, the present invention provides a supporting drilling tool for reverse circulation drilling of a large-diameter down-the-hole hammer, which includes a double-wall drill pipe 200, a forward and reverse joint 300, a down-the-hole hammer 400, and an airflow packer 100 for reverse circulation drilling of a large-diameter down-the-hole hammer in the above-mentioned embodiment 3, which are connected in sequence. Among them, the double-wall drill pipe 200 is provided with a double channel for conveying high-pressure air downward and returning rock cuttings and slag upward, respectively, the forward and reverse joint 300 is fixedly arranged at the bottom of the double-wall drill pipe 200, and the forward and reverse joint 300 is provided with a conveying hole (for conveying high-pressure air or other high-pressure media) and a guide hole 310 (for returning rock cuttings and slag upward) which are respectively connected to the double channels of the double-wall drill pipe 200, the down-the-hole hammer 400 is fixedly arranged at the bottom of the forward and reverse joint 300, and the down-the-hole hammer 400 includes a drill bit and an impactor connected thereto. It should be noted that the present embodiment specifically adopts a composite reverse circulation drilling process consisting of a "down-the-hole hammer + forward and reverse cross joints + double-wall drill pipe". Its essence is that the airflow circulates upward through the outer side of the bottom down-the-hole hammer 400 in a positive cycle, and enters the central channel of the double-wall drill pipe 200 through the guide hole 310 of the forward and reverse joints 300 at the upper end of the down-the-hole hammer 400 to form a reverse circulation. The double-wall drill pipe 200, the forward and reverse joints 300, and the down-the-hole hammer 400 are all mature existing technologies in this field, and their specific structures and principles are not repeated here.

[0037] like Fig.11As shown, at least one air flow packer 100 is provided, and the air flow packer 100 is movably sleeved on the outer periphery of the double-wall drill pipe 200. Specifically, the air flow packer 100 is rotatably sleeved on the outer periphery of the double-wall drill pipe 200, and it is synchronously axially lifted and lowered with the double-wall drill pipe 200, so that during the drilling process, the air flow packer 100 does not rotate with the double-wall drill pipe 200, thereby reducing the collision and friction between it and the borehole wall. In addition, a plurality of air flow packers 100 are arranged at intervals along the axial direction of the double-wall drill pipe 200 to further enhance the overall blocking effect, thereby ensuring the wind pressure and air volume required for returning and removing chips during the drilling process, so that the drilling construction can be carried out stably and efficiently. At the same time, the position and spacing of adjacent air flow packers 100 can be reasonably set according to the actual geological rock formation characteristics, so as to be able to cross the "gas escape zone" or "gas leakage zone" caused by the collapse of the borehole wall or the existence of large holes in the rock formation, thereby ensuring the uninterrupted and stable progress of the cyclic drilling work.

[0038] Further, combined with Fig.11 and Fig.12 As shown, the supporting drilling tools for reverse circulation drilling of a large-diameter down-the-hole hammer provided by the present invention also include a powder scooping tube 500, wherein the powder scooping tube 500 is fixedly sleeved on the outer periphery of the double-wall drill pipe 200 so that it can rotate synchronously with the double-wall drill pipe 200, and the powder scooping tube 500 is located above the airflow packer 100.

[0039] Specifically, the top of the powder dredger 500 is provided with an oblique cut, and the outer edge of the oblique cut is provided with a cleaning ring convex 510 to crush and clean the larger pieces on the upper part of the borehole wall and collect them, so as to prevent the occurrence of drill jamming accidents. The cleaning ring convex 510 can be made of hard alloy to ensure the crushing effect and prolong the service life. It should be noted that the cross section of the cleaning ring convex 510 is a trapezoidal protrusion protruding outward. At the same time, in order to avoid the drill jamming phenomenon during the actual drilling construction, the protruding end of the cleaning ring convex 510 can be made into a smooth curved surface to avoid the collision and drill jamming phenomenon between the drill hole wall caused by the angular structure. In actual use, after drilling to a certain depth (such as 50m), the powder dredger 500 and the double-wall drill rod 200 can be lifted upward to clean the rock cuttings and rock powder collected inside the powder dredger 500 in time.

[0040] Further, combined with Fig.11 and Fig.13As shown, the supporting drilling tools for reverse circulation drilling of a large-diameter down-the-hole hammer provided by the present invention also include an airflow diversion sleeve 600, wherein the airflow diversion sleeve 600 is fixedly sleeved on the outer periphery of the forward and reverse joints 300 and the down-the-hole hammer 400. The setting of the airflow diversion sleeve 600 reduces the outer annular space gap of the drilling well, that is, reduces the annular gap and the circulation cross-sectional area between the down-the-hole hammer 400 and the borehole wall, thereby avoiding the phenomenon of weakened upward return wind speed and insufficient wind pressure caused by excessive annular gap and circulation cross-sectional area, thereby ensuring that the rock cuttings and rock powder can be discharged to the outside in a timely and efficient manner.

[0041] Specifically, the top of the airflow splitting sleeve 600 is fixedly connected to the forward and reverse joints 300 through a connecting flange, and the top of the airflow splitting sleeve 600 is located below the guide hole 310 of the forward and reverse joints, and the bottom of the airflow splitting sleeve 600 is provided with an opening, and the drill bit of the down-the-hole hammer 400 extends outward through the opening portion. Fig.13 As shown, an annular frame plate 610 arranged near the opening is arranged inside the airflow splitting sleeve 600, and the annular frame plate 610 is fixedly arranged on the outer periphery of the down-the-hole hammer 400. Further, the annular frame plate 610 is fixedly arranged (rigidly connected) on the outer periphery of the impactor of the down-the-hole hammer 400, and is arranged close to the drill bit of the down-the-hole hammer 400.

[0042] It should be noted that the vertical distance between the bottom of the airflow diversion sleeve 600 and the drill bit can be set according to specific needs. Under the premise of not affecting the normal drilling of the drill bit, a reasonable vertical spacing can be set according to the working clearance of the drill bit.

[0043] To sum up, the air flow packer for reverse circulation drilling with a large-diameter down-the-hole hammer provided by the present invention can adapt to the uneven wall surface of the borehole, so that the outer edge of the air flow packer is in close contact with the borehole wall, thereby improving the air flow blocking effect and ensuring the stable and efficient circulation drilling work. At the same time, it reduces the impact and friction between the outer edge of the air flow packer and the borehole wall, reduces the wear of the air flow packer caused thereby, and extends the service life of the air flow packer.

[0044] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. All equivalent changes and modifications made within the scope of the present invention should still fall within the scope of the present invention.

Claims

1. An air flow packer for reverse circulation drilling with a large-caliber down-the-hole hammer, characterized in that: The invention comprises an isolation ring sleeve (110) having a mounting hole (111) at the center thereof, wherein an outer ring wall of the isolation ring sleeve (110) is provided with an isolation contact protrusion (120) extending outward, wherein a plurality of the isolation contact protrusions (120) are provided and are evenly spaced and distributed in a circumferential direction with the axis of the isolation ring sleeve (110) as the center.

2. The air flow packer for reverse circulation drilling of large-caliber down-the-hole hammer according to claim 1 is characterized by: The isolation contact spigot (120) comprises a contact spigot base (121) fixedly arranged on the outer ring wall of the isolation ring sleeve (110), a contact spigot head (122) movably sleeved on the outer periphery of the contact spigot base (121), and a telescopic spring (123) fixedly embedded in the contact spigot base (121); The end of the telescopic spring (123) abuts against the contact protrusion head (122).

3. The air flow packer for reverse circulation drilling of large-caliber down-the-hole hammer according to claim 1 is characterized by: The isolation ring sleeve (110) is provided with a plurality of groups of isolation contacts (120) at intervals along the axial direction thereof, and the isolation contacts (120) in adjacent groups in the axial direction are arranged in an axially cross-staggered manner.

4. The air flow packer for reverse circulation drilling of large-caliber down-the-hole hammer according to claim 3 is characterized by: The outer ring wall of the isolation ring sleeve (110) is also provided with elastic protrusions (130) extending outwards, and a plurality of the elastic protrusions (130) are provided and are evenly spaced and distributed along the circumferential direction with the axis of the isolation ring sleeve (110) as the center; The elastic contact protrusion (130) is located between adjacent groups of isolation contact protrusions (120) that are arranged axially at intervals.

5. The air flow packer for reverse circulation drilling of large-caliber down-the-hole hammer according to claim 1 is characterized by: The sealing ring sleeve (110) is further provided with at least one axially penetrating chip leakage hole (140), and a sealing plate (150) movably arranged at the chip leakage hole (140); The sealing plate (150) is movably arranged at the bottom of the sealing ring sleeve (110) so as to realize the opening and closing of the chip leakage hole (140) by turning over the sealing plate (150).

6. The air flow packer for reverse circulation drilling of large-caliber down-the-hole hammer according to claim 5 is characterized by: The bottom of the sealing ring sleeve (110) is provided with a receiving groove matched with the sealing plate (150), and the sealing plate (150) is movably embedded in the receiving groove via a hinge shaft (160); Both ends of the hinge shaft (160) are sleeved with a flip torsion spring (170); one end of the flip torsion spring (170) is fixedly connected to the sealing ring sleeve (110), and the other end is fixedly connected to the sealing plate (150).

7. The air flow packer for reverse circulation drilling of large-diameter down-the-hole hammer according to claim 1 is characterized by: The sealing ring sleeve (110) is provided with a sealing bearing (112) fixedly connected thereto, and the sealing bearing (112) is located at the mounting hole (111).

8. A large-caliber down-the-hole hammer reverse circulation drilling supporting drilling tool, comprising a double-wall drill pipe, a forward and reverse joint and a down-the-hole hammer connected in sequence, characterized in that: It also includes an air flow packer for reverse circulation drilling of a large-diameter down-the-hole hammer as described in any one of claims 1 to 7: at least one air flow packer (100) is provided, and its movable sleeve is arranged on the outer periphery of the double-wall drill pipe (200).

9. The large-caliber down-the-hole hammer reverse circulation drilling supporting drilling tool according to claim 8 is characterized in that: It also includes a powder scooping tube (500) fixedly sleeved on the outer circumference of the double-wall drill pipe (200), wherein the powder scooping tube (500) is located above the airflow packer (100); The top of the flour scooping tube (500) is provided with an oblique cut, and the outer edge of the oblique cut is provided with a cleaning annular protrusion (510) fixedly arranged on the outer side wall of the flour scooping tube (500).

10. The large-caliber down-the-hole hammer reverse circulation drilling supporting drilling tool according to claim 8, characterized in that: It also includes an airflow splitting sleeve (600) fixedly sleeved on the outer periphery of the forward and reverse joints (300) and the down-the-hole hammer (400), wherein the top of the airflow splitting sleeve (600) is fixedly connected to the forward and reverse joints (300), and an opening is provided at the bottom; An annular frame plate (610) arranged close to the opening is arranged inside the airflow splitting sleeve (600), and the annular frame plate (610) is fixedly connected to the down-the-hole hammer (400).

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