Rotary drilling rig drill pipe

Abstract

The present invention discloses a drill pipe for a rotary drilling rig, which includes an outer joint rod and an inner joint rod that are telescopically sleeved. Inner key plates are provided on the inner wall of the pipe body of the outer joint rod, and a mechanical locking rod slideway and a friction rod slideway are provided on the outer wall of the pipe body of the inner joint rod. The inner key plates on the outer joint rod are selectively slidably engaged with the mechanical locking rod slideway and the friction rod slideway on the inner joint rod. For the drill pipe of the rotary drilling rig in the embodiment of the present invention, since the mechanical locking rod slideway and the friction rod slideway are simultaneously provided on the outer wall of the inner joint rod, the inner key plates on the inner wall of the outer joint rod can be engaged with the mechanical locking rod slideway or the friction rod slideway, so as to switch between the mechanical locking rod and the friction rod according to the needs of the formation, realizing multiple uses of one rod, improving the application range of the drill pipe of the rotary drilling rig, being able to adapt to various working conditions, and having a relatively high drilling efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of rotary drilling rigs, and particularly to a drill pipe for a rotary drilling rig. Background Art

[0002] A rotary drilling rig is a construction machine suitable for hole forming operations in building foundation engineering. It is mainly suitable for construction in soil layers such as sandy soil, cohesive soil, and silty soil, and is widely used in various foundation construction operations such as cast-in-place piles, diaphragm walls, and foundation reinforcement. Generally, it adopts a hydraulic crawler telescopic chassis, a self-lifting and foldable drill mast, a telescopic drill pipe, with vertical automatic detection and adjustment, hole depth digital display, etc. The whole machine operation generally adopts hydraulic pilot control and load sensing, with the characteristics of easy operation and comfort.

[0003] At present, there are mainly three types of drill pipes for rotary drilling rigs: mechanically locked drill pipes, friction drill pipes, and combined drill pipes. All are composed of multiple sections of drill pipes. When the drill pipe specification is determined, the more the number of drill pipe sections, the smaller the diameter of the core drill pipe. Mechanically locked drill pipes can transmit greater pressing force and are suitable for construction drilling in hard strata. However, their operation is complex. Each time of drilling, a locking point needs to be found. After drilling is completed, reverse unlocking and then lifting are required. If the unlocking is not complete, serious faults such as rod dragging and rod smashing will occur, and the operation level requirement for the machine operator is relatively high. Moreover, when the strata are not hard, the drilling efficiency is relatively low when using mechanically locked drill pipes for drilling. Friction drill pipes are easy to operate. They can be directly lifted and lowered without unlocking, and the drilling efficiency is high. However, the pressing force they can transmit is small and they cannot be used for construction drilling in hard strata, and are only suitable for construction drilling in soft strata. For combined drill pipes, when the inner friction drill pipe section has not extended, they can transmit greater pressing force and can drill in high-hardness strata. When the drilling depth reaches a certain value, after the inner friction drill pipe section extends, a large pressing force cannot be applied and hard strata cannot be broken. And when the outer mechanically locked drill pipe is locked and the inner friction drill pipe is drilling, when the strata change and normal drilling cannot be carried out, the outer mechanically locked drill pipe cannot be unlocked due to insufficient unlocking reverse torque. It is only suitable for working conditions where the pile hole is relatively deep and the strata at the lower part of the pile hole are soft. It can be seen that the three types of drill pipes on the current market cannot be used universally in various working conditions. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a drill pipe for a rotary drilling rig with a wider application range and capable of adapting to more working conditions.

[0005] The present invention provides a drill pipe for a rotary drilling rig, including an outer section rod and an inner section rod that are telescopically sleeved. An inner key plate is provided on the inner wall of the pipe body of the outer section rod, and a mechanically locked rod slideway and a friction rod slideway are provided on the outer wall of the pipe body of the inner section rod. The inner key plate of the outer section rod selectively slides and mates with the mechanically locked rod slideway and the friction rod slideway of the inner section rod.

[0006] In one embodiment, middle guiding external keys, full-course guiding external keys and pressure port external keys which are arranged at intervals in the circumferential direction are provided on the outer wall of the tube body of the inner joint rod. A machine locking rod slideway is formed between the middle guiding external key and the full-course guiding external key, and a friction rod slideway is formed between the full-course guiding external key and the pressure port external key. An upper locking piece and a lower locking piece are arranged on one side of the pressure port external key. The lower locking piece and the pressure port external key form a pressure port which is used for meshing with the inner key plate.

[0007] In one embodiment, a plurality of the lower locking pieces which are arranged along the telescopic direction of the outer joint rod and the inner joint rod can be provided on the inner wall of the tube body of the inner joint rod. A plurality of the inner key plates which are arranged along the telescopic direction of the outer joint rod and the inner joint rod are provided on the inner wall of the tube body of the outer joint rod. The plurality of inner key plates are respectively matched with the plurality of lower locking pieces.

[0008] In one embodiment, the distance between two adjacent inner key plates is equal to the distance between two adjacent lower locking pieces.

[0009] In one embodiment, the width dimensions of the machine locking rod slideway and the friction rod slideway of the inner joint rod are the same and correspond to the width of the inner key plate.

[0010] In one embodiment, a plurality of the machine locking rod slideways and a plurality of the friction rod slideways are provided on the outer wall of the tube body of the inner joint rod in the circumferential direction. The plurality of machine locking rod slideways and the plurality of friction rod slideways are arranged alternately at intervals. A plurality of the inner key plates are provided on the inner wall of the tube body of the outer joint rod in the circumferential direction.

[0011] In one embodiment, the first section rod, the second section rod, the third section rod and the fourth section rod of the rotary drilling rig drill pipe are provided. The second section rod is telescopically sleeved in the first section rod, the third section rod is telescopically sleeved in the second section rod, and the fourth section rod is telescopically sleeved in the third section rod. The first section rod includes a first pipe body, and a first inner key plate is provided on the inner wall of the first pipe body. The second section rod includes a second pipe body, and a second mechanical locking rod slideway and a second friction rod slideway are provided on the outer wall of the second pipe body. The first inner key plate of the first section rod is selectively slidably engaged with the second mechanical locking rod slideway and the second friction rod slideway. A second inner key plate is provided on the inner wall of the second pipe body of the second section rod. The third section rod includes a third pipe body, and a third mechanical locking rod slideway and a third friction rod slideway are provided on the outer wall of the third pipe body. The second inner key plate of the second section rod is selectively slidably engaged with the third mechanical locking rod slideway and the third friction rod slideway. A third inner key plate is provided on the inner wall of the third pipe body. The fourth section rod includes a fourth pipe body, and a fourth mechanical locking rod slideway and a fourth friction rod slideway are provided on the outer wall of the fourth pipe body. The third inner key plate of the third section rod is selectively slidably engaged with the fourth mechanical locking rod slideway and the fourth friction rod slideway.

[0012] In one embodiment, the widths of the second mechanical locking rod slideway and the second friction rod slideway of the second section rod are the same and correspond to the width of the first inner key plate. The widths of the third mechanical locking rod slideway and the third friction rod slideway of the third section rod are the same and correspond to the width of the second inner key plate. The widths of the fourth mechanical locking rod slideway and the fourth friction rod slideway of the fourth section rod are the same and correspond to the width of the third inner key plate.

[0013] In one embodiment, second middle guiding outer keys, second full-course guiding outer keys and second pressure port outer keys are arranged on the outer wall of the second pipe body at circumferential intervals. A second machine lock rod slideway is formed between the second middle guiding outer keys and the second full-course guiding outer keys. A second friction rod slideway is formed between the second full-course guiding outer keys and the second pressure port outer keys. A second upper locking piece and a second lower locking piece are arranged on one side of the second pressure port outer key. The second lower locking piece and the second pressure port outer key form a second pressure port. A second bottom guiding outer key is further arranged at one end of the second pipe body. The second bottom guiding outer key corresponds to the second middle guiding outer key in the circumferential direction of the second pipe body; third middle guiding outer keys, third full-course guiding outer keys and third pressure port outer keys are arranged on the outer wall of the third pipe body at circumferential intervals. A third machine lock rod slideway is formed between the third middle guiding outer keys and the third full-course guiding outer keys. A third friction rod slideway is formed between the third full-course guiding outer keys and the third pressure port outer keys. A third upper locking piece and a third lower locking piece are arranged on one side of the third pressure port outer key. The third lower locking piece and the third pressure port outer key form a third pressure port. A third bottom guiding outer key is further arranged at one end of the third pipe body. The third bottom guiding outer key corresponds to the third middle guiding outer key in the circumferential direction of the third pipe body; fourth middle guiding outer keys, fourth full-course guiding outer keys and fourth pressure port outer keys are arranged on the outer wall of the fourth pipe body at circumferential intervals. A fourth machine lock rod slideway is formed between the fourth middle guiding outer keys and the fourth full-course guiding outer keys. A fourth friction rod slideway is formed between the fourth full-course guiding outer keys and the fourth pressure port outer keys. A fourth upper locking piece and a fourth lower locking piece are arranged on one side of the fourth pressure port outer key. The fourth lower locking piece and the fourth pressure port outer key form a fourth pressure port. A fourth bottom guiding outer key is further arranged at one end of the fourth pipe body. The fourth bottom guiding outer key corresponds to the fourth middle guiding outer key in the circumferential direction of the fourth pipe body; a plurality of the fourth lower locking pieces may be arranged on the inner wall of the fourth pipe body along the telescopic direction of the first rod section and the second rod section. A plurality of third inner key plates are arranged on the inner wall of the third pipe body of the third rod section along the telescopic direction of the first rod section and the second rod section. The plurality of third inner key plates are respectively matched with the plurality of fourth lower locking pieces.

[0014] In one embodiment, a first machine lock rod slideway and a first friction rod slideway are arranged on the outer wall of the first pipe body. One of the first machine lock rod slideway and the first friction rod slideway is used to cooperate with an inner key on the inner side wall of the power head to connect the first rod section with the power head.

[0015] The drill pipe of the rotary drilling rig provided by the embodiment of the present invention has a mechanical locking rod slideway and a friction rod slideway simultaneously arranged on the outer wall of the inner joint rod. The inner key plate on the inner wall of the outer joint rod can cooperate with the mechanical locking rod slideway or the friction rod slideway, so as to switch between the mechanical locking rod and the friction rod according to the needs of the formation, realizing multiple functions with one rod, improving the application range of the drill pipe of the rotary drilling rig, being able to adapt to various working conditions, and having a relatively high drilling efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present invention, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can also be obtained based on these drawings without creative efforts.

[0017] Figure 1 It is a schematic diagram of the overall structure of the drill pipe of the rotary drilling rig according to an embodiment of the present invention.

[0018] Figure 2 It is Figure 1 a schematic cross-sectional view taken along line A-A in

[0019] Figure 3 It is Figure 2 a schematic cross-sectional view taken along line B-B in

[0020] Figure 4 It is Figure 1 a schematic cross-sectional view taken along line C-C in

[0021] Figure 5 It is Figure 4 a schematic cross-sectional view taken along line D-D in

[0022] Figure 6 It is Figure 1 a schematic cross-sectional view taken along line E-E in

[0023] Figure 7 It is Figure 6 a schematic cross-sectional view taken along line F-F in

[0024] Figure 8 It is Figure 1 a schematic diagram of the structure of the drill pipe of the rotary drilling rig when it is a mechanical locking rod in

[0025] Figure 9 It is Figure 1 a schematic diagram of the structure of the drill pipe of the rotary drilling rig when it is a friction rod in DETAILED DESCRIPTION OF THE EMBODIMENTS

[0026] Specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the description of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0027] In the description of the present invention, unless otherwise clearly defined and limited, terms such as "arranged", "installed", "connected", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific situations.

[0028] The orientation or positional relationship indicated by terms such as "upper", "lower", "left", "right", "front", "rear", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the invention product is usually placed during use. It is only for the convenience of description and simplification of description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present invention.

[0029] Terms such as "first", "second", "third", etc. are only used to distinguish elements with similar attributes, rather than indicating or implying relative importance or a specific order.

[0030] The term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion. In addition to including the listed elements, it may also include other elements not specifically listed.

[0031] The present invention provides a drill pipe for a rotary drilling rig, which includes multiple drill pipes that are telescopically sleeved in sequence. For two drill pipes that are telescopically sleeved with each other, the outer drill pipe can be called the outer joint rod, and the inner drill pipe can be called the inner joint rod. For example, in a drill pipe of a rotary drilling rig including four drill pipes, for the first drill pipe and the second drill pipe, the first drill pipe is the outer joint rod and the second drill pipe is the inner joint rod; for the second drill pipe and the third drill pipe, the second drill pipe is the outer joint rod and the third drill pipe is the inner joint rod; for the third drill pipe and the fourth drill pipe, the third drill pipe is the outer joint rod and the fourth drill pipe is the inner joint rod. Among them, inner key plates are provided on the inner wall of the pipe body of the outer joint rod, and a mechanical locking rod slideway and a friction rod slideway are provided on the outer wall of the pipe body of the inner joint rod. The inner key plate of the outer joint rod selectively slides and mates with the mechanical locking rod slideway and the friction rod slideway of the inner joint rod. The multiple drill pipes can be two or more drill pipes with any number. Specifically, the widths of the mechanical locking rod slideway and the friction rod slideway of the inner joint rod are the same and correspond to the width of the inner key plate.

[0032] Specifically, on the outer wall of the tube body of the inner joint rod, middle guiding external keys, full-course guiding external keys and pressure port external keys are arranged at circumferential intervals. A locking rod slideway is formed between the middle guiding external key and the full-course guiding external key, and a friction rod slideway is formed between the full-course guiding external key and the pressure port external key. On one side of the pressure port external key, an upper locking piece and a lower locking piece are provided. The lower locking piece and the pressure port external key form a pressure port, and the pressure port is used for meshing with the inner key plate.

[0033] Specifically, on the inner wall of the tube body of the inner joint rod, a plurality of lower locking pieces can be arranged along the telescopic direction of the outer joint rod and the inner joint rod. On the inner wall of the tube body of the outer joint rod, a plurality of inner key plates are arranged along the telescopic direction of the outer joint rod and the inner joint rod. The plurality of inner key plates are respectively matched with the plurality of lower locking pieces to transmit torque and pressure. By arranging a plurality of inner key plates, multiple sets of locking points are simultaneously pressurized, which can improve the compressive strength safety factor and wear resistance of the drill pipe of the rotary drilling rig. Especially for the inner joint drill pipe with a smaller diameter, its slideway size is small and its strength is insufficient. After arranging multiple sets of locking points, its strength is improved.

[0034] Specifically, the distance between two adjacent inner key plates is equal to the distance between two adjacent lower locking pieces.

[0035] In the drill pipe of the rotary drilling rig of this embodiment, since the locking rod slideway and the friction rod slideway are simultaneously arranged on the outer wall of the inner joint rod, the inner key plate on the inner wall of the outer joint rod can be matched with the locking rod slideway or the friction rod slideway, so as to switch between the locking rod and the friction rod according to the formation requirements, realizing multiple uses of one rod, improving the application range of the drill pipe of the rotary drilling rig, being able to adapt to various working conditions, and having a higher drilling efficiency.

[0036] Please refer Figure 1 and Figure 2 , in this embodiment, the drill pipe of the rotary drilling rig includes four joint rods, specifically including a first joint rod 11, a second joint rod 13, a third joint rod 15 and a fourth joint rod 17. The second joint rod 13 is telescopically sleeved in the first joint rod 11, the third joint rod 15 is telescopically sleeved in the second joint rod 13, and the fourth joint rod 17 is telescopically sleeved in the third joint rod 15. The first joint rod 11 includes a first tube body 112. On the inner wall of the first tube body 112, a first inner key plate 113 is provided. On the outer wall of the first tube body 112, a first locking rod slideway 114 and a first friction rod slideway 115 are provided. One of the first locking rod slideway 114 and the first friction rod slideway 115 is used for cooperating with the inner key on the inner side wall of the power head (not shown in the figure) to connect the first joint rod 11 with the power head. The second joint rod 13 includes a second tube body 132. On the outer wall of the second tube body 132, a second locking rod slideway 134 and a second friction rod slideway 135 are provided. The first inner key plate 113 of the first joint rod 11 selectively slides and cooperates with the second locking rod slideway 134 and the second friction rod slideway 135.

[0037] In this embodiment, please refer to Figure 3 together. The width dimensions of the first locking rod slideway 114 and the first friction rod slideway 115 of the first section rod 11 are the same.

[0038] Specifically, a plurality of first inner key plates 113 are provided along the circumferential direction on the inner wall of the first pipe body 112 of the first section rod 11. Specifically, there are three first inner key plates 113. Of course, the number of the first inner key plates 113 can also be other numbers.

[0039] Specifically, a plurality of first locking rod slideways 114 and a plurality of first friction rod slideways 115 are provided along the circumferential direction on the outer wall of the first pipe body 112 of the first section rod 11. Specifically, there are three first locking rod slideways 114 and three first friction rod slideways 115 respectively. Of course, the number of the first locking rod slideways 114 and the first friction rod slideways 115 can also be other numbers. More specifically, the plurality of first locking rod slideways 114 and the first friction rod slideways 115 are alternately arranged at intervals.

[0040] Specifically, a first middle guiding outer key 117, a first full-length guiding outer key 118 and a first pressure port outer key 119 are provided on the outer wall of the first pipe body 112 at intervals along the circumferential direction. A first locking rod slideway 114 is formed between the first middle guiding outer key 117 and the first full-length guiding outer key 118, and a first friction rod slideway 115 is formed between the first full-length guiding outer key 118 and the first pressure port outer key 119. A first upper locking piece 121 and a first lower locking piece 122 are provided on one side of the first pressure port outer key 119, and the first lower locking piece 122 and the first pressure port outer key 119 form a first pressure port 124. Specifically, there are three first middle guiding outer keys 117, first full-length guiding outer keys 118, first pressure port outer keys 119, first upper locking pieces 121 and first lower locking pieces 122 respectively. Of course, the number can also be other numbers.

[0041] Specifically, a first bottom reinforcing plate 125 is provided at one end of the outer wall of the first pipe body 112 to strengthen the strength of the first section rod 11.

[0042] Specifically, a first bottom guiding outer key 126 is further provided at the end of the outer wall of the first pipe body 112 where the first bottom reinforcing plate 125 is provided. The first bottom guiding outer key 126 corresponds to the first middle guiding outer key 117 in the circumferential direction of the first pipe body 112.

[0043] In this embodiment, please refer to Figure 4 and Figure 5 together. A second inner key plate 133 is provided on the inner wall of the second pipe body 132 of the second section rod 13.

[0044] Specifically, the widths of the second locking rod slideway 134 and the second friction rod slideway 135 of the second rod 13 are the same, both being L1, and corresponding to the width of the first inner key plate 113.

[0045] Specifically, a plurality of second locking rod slideways 134 and a plurality of second friction rod slideways 135 are circumferentially provided on the outer wall of the second pipe body 132 of the second rod 13. Specifically, there are three second locking rod slideways 134 and three second friction rod slideways 135 respectively. Of course, the number of the second locking rod slideways 134 and the second friction rod slideways 135 can also be other numbers. More specifically, the plurality of second locking rod slideways 134 and the plurality of second friction rod slideways 135 are alternately arranged at intervals.

[0046] Specifically, second middle guiding outer keys 137, second full-course guiding outer keys 138 and second pressure application port outer keys 139 are circumferentially arranged at intervals on the outer wall of the second pipe body 132. A second locking rod slideway 134 is formed between the second middle guiding outer key 137 and the second full-course guiding outer key 138, and a second friction rod slideway 135 is formed between the second full-course guiding outer key 138 and the second pressure application port outer key 139. A second upper locking piece 141 and a second lower locking piece 142 are arranged on one side of the second pressure application port outer key 139, and the second lower locking piece 142 and the second pressure application port outer key 139 form a second pressure application port 144. Specifically, there are three second middle guiding outer keys 137, second full-course guiding outer keys 138, second pressure application port outer keys 139, second upper locking pieces 141 and second lower locking pieces 142 respectively. Of course, the number can also be other numbers.

[0047] Specifically, a second bottom reinforcing plate 145 is provided at one end of the outer wall of the second pipe body 132 to strengthen the strength of the second rod 13.

[0048] Specifically, a second bottom guiding outer key 146 is further provided at the end of the outer wall of the second pipe body 132 where the second bottom reinforcing plate 145 is provided. The second bottom guiding outer key 146 corresponds to the second middle guiding outer key 137 in the circumferential direction of the second pipe body 132.

[0049] In this embodiment, please refer to Figure 6 and Figure 7 , the third rod 15 includes a third pipe body 152. A third inner key plate 153 is provided on the inner wall of the third pipe body 152. A third locking rod slideway 154 and a third friction rod slideway 155 are provided on the outer wall of the third pipe body 152. The second inner key plate 133 of the second rod 13 is selectively in sliding fit with the third locking rod slideway 154 and the third friction rod slideway 155. The widths of the third locking rod slideway 154 and the third friction rod slideway 155 of the third rod 15 are the same, both being L2, and corresponding to the width of the second inner key plate 133.

[0050] Specifically, a plurality of third locking rod slideways 154 and a plurality of third friction rod slideways 155 are circumferentially arranged on the outer wall of the third tube body 152 of the third section rod 15. Specifically, there are three third locking rod slideways 154 and three third friction rod slideways 155 respectively. Of course, the number of the third locking rod slideways 154 and the third friction rod slideways 155 can also be other numbers. More specifically, the plurality of third locking rod slideways 154 and the plurality of third friction rod slideways 155 are arranged at intervals alternately.

[0051] Specifically, third middle guiding outer keys 157, third full-length guiding outer keys 158 and third pressure port outer keys 159 are arranged at intervals circumferentially on the outer wall of the third tube body 152. A third locking rod slideway 154 is formed between the third middle guiding outer key 157 and the third full-length guiding outer key 158, and a third friction rod slideway 155 is formed between the third full-length guiding outer key 158 and the third pressure port outer key 159. On one side of the third pressure port outer key 159, there are a third upper locking piece 161 and a third lower locking piece 162, and the third lower locking piece 162 and the third pressure port outer key 159 form a third pressure port 164. Specifically, there are three third middle guiding outer keys 157, three third full-length guiding outer keys 158, three third pressure port outer keys 159, three third upper locking pieces 161 and three third lower locking pieces 162 respectively. Of course, the number can also be other numbers.

[0052] Specifically, a third bottom reinforcing plate 165 is arranged at one end of the outer wall of the third tube body 152 to strengthen the strength of the third section rod 15.

[0053] Specifically, a third bottom guiding outer key 166 is also arranged at the end of the outer wall of the third tube body 152 where the third bottom reinforcing plate 165 is arranged. The third bottom guiding outer key 166 corresponds to the third middle guiding outer key 157 in the circumferential direction of the third tube body 152.

[0054] In this embodiment, the fourth section rod 17 includes a fourth tube body 172. A fourth locking rod slideway 174 and a fourth friction rod slideway 175 are arranged on the outer wall of the fourth tube body 172. The third inner key plate 153 of the third section rod 15 is selectively in sliding fit with the fourth locking rod slideway 174 and the fourth friction rod slideway 175. The width dimensions of the fourth locking rod slideway 174 and the fourth friction rod slideway 175 of the fourth section rod 17 are the same, both being L3, and corresponding to the width of the third inner key plate 153. Since only four sections of drill rods are included in the rotary drilling rig in this embodiment, there is no need to arrange an inner key plate on the inner wall of the fourth section rod 17. When a fourth inner section rod needs to be sleeved inside the fourth section rod 17, an inner key plate is arranged on the inner wall of the fourth section rod 17.

[0055] Specifically, a plurality of fourth mechanical locking rod slideways 174 and a plurality of fourth friction rod slideways 175 are circumferentially arranged on the outer wall of the fourth pipe body 172 of the fourth section rod 17. Specifically, there are three fourth mechanical locking rod slideways 174 and three fourth friction rod slideways 175 respectively. Of course, the number of the fourth mechanical locking rod slideways 174 and the fourth friction rod slideways 175 can also be other numbers. More specifically, the plurality of fourth mechanical locking rod slideways 174 and the plurality of fourth friction rod slideways 175 are alternately arranged at intervals.

[0056] Specifically, fourth middle guiding outer keys 177, fourth full-length guiding outer keys 178 and fourth pressure port outer keys 179 are arranged at intervals circumferentially on the outer wall of the fourth pipe body 172. A fourth mechanical locking rod slideway 174 is formed between the fourth middle guiding outer key 177 and the fourth full-length guiding outer key 178, and a fourth friction rod slideway 175 is formed between the fourth full-length guiding outer key 178 and the fourth pressure port outer key 179. A fourth upper locking piece 181 and a fourth lower locking piece 182 are arranged on one side of the fourth pressure port outer key 179, and the fourth lower locking piece 182 and the fourth pressure port outer key 179 form a fourth pressure port 184. Specifically, there are three fourth middle guiding outer keys 177, three fourth full-length guiding outer keys 178, three fourth pressure port outer keys 179, three fourth upper locking pieces 181 and three fourth lower locking pieces 182 respectively. Of course, the number can also be other numbers.

[0057] Specifically, a plurality of fourth lower locking pieces 182 arranged along the telescopic direction of the first section rod 11 and the second section rod 13 can be provided on the inner wall of the fourth pipe body 172, and a plurality of third inner key plates 153 arranged along the telescopic direction of the first section rod 11 and the second section rod 13 are provided on the inner wall of the third pipe body 152 of the third section rod 15. The plurality of third inner key plates 153 cooperate with the plurality of fourth lower locking pieces 182 respectively. More specifically, in the telescopic direction of the first section rod 11 and the second section rod 13, the distance L4 between two adjacent third inner key plates 153 (i.e., the distance between the top of one third inner key plate 153 and the top of the adjacent third inner key plate 153) is equal to the distance L4 between two adjacent fourth lower locking pieces 182 (i.e., the distance between the top of one fourth lower locking piece 182 and the top of the adjacent fourth lower locking piece 182). In this way, both the upper and lower ends of the third inner key plate 153 are in contact with the fourth lower locking piece 182 to better transmit torque and pressing force. In the telescopic direction of the first section rod 11 and the second section rod 13, the distance between two adjacent fourth lower locking pieces 182 is less than the stroke of the pressurizing oil cylinder of the rotary drilling rig to ensure that locking and pressurizing can be carried out. It can be understood that a plurality of inner key plates and a plurality of lower locking pieces can also be arranged between other two drill rods, which is not limited here.

[0058] Specifically, a fourth bottom guiding outer key 186 is further provided at one end of the fourth pipe body 172 where the drilling tool is arranged. The fourth bottom guiding outer key 186 corresponds to the fourth middle guiding outer key 177 in the circumferential direction of the fourth pipe body 172.

[0059] Specifically, one end of the drill tool provided with the fourth rod 17 is further provided with a water flow tray 191 and a buffer member 193.

[0060] Please refer Figure 8 , when the first inner key plate 113 cooperates with the second machine lock rod slideway 134, the second inner key plate 133 cooperates with the third machine lock rod slideway 154, and the third inner key plate 153 cooperates with the fourth machine lock rod slideway 174, the drill pipe of the rotary drilling rig is a machine lock type drill pipe, which can transmit a large pressing force and is suitable for hard strata; please refer Figure 9 , when the first inner key plate 113 cooperates with the second friction rod slideway 135, the second inner key plate 133 cooperates with the third machine friction rod slideway 155, and the third inner key plate 153 cooperates with the fourth friction rod slideway 175, the drill pipe of the rotary drilling rig is a friction type drill pipe, which can transmit a smaller pressing force, has a lower drilling efficiency, is simple to operate, and is suitable for soft strata.

[0061] It should be noted that each embodiment in this specification is described in a progressive manner. The key point of each embodiment is to illustrate the differences from other embodiments. The same or similar parts among the embodiments can be referred to each other.

[0062] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed by the present invention should be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the appended claims.

Claims

1. A drill pipe for a rotary drilling rig, characterized in that, It includes an outer section rod and an inner section rod that are telescopically sleeved. On the inner wall of the tube body of the outer section rod, a plurality of inner key plates are circumferentially arranged along the telescopic direction of the outer section rod and the inner section rod. On the outer wall of the tube body of the inner section rod, a plurality of mechanical locking rod slides and a plurality of friction rod slides are circumferentially arranged. The plurality of mechanical locking rod slides and the plurality of friction rod slides are alternately and spacedly arranged. The plurality of inner key plates of the outer section rod are selectively slidably engaged with the plurality of mechanical locking rod slides and the plurality of friction rod slides of the inner section rod; on the outer wall of the tube body of the inner section rod, a middle guiding outer key, a full-length guiding outer key, and a pressure port outer key are circumferentially and spacedly arranged. A mechanical locking rod slide is formed between the middle guiding outer key and the full-length guiding outer key, and a friction rod slide is formed between the full-length guiding outer key and the pressure port outer key. On one side of the pressure port outer key, an upper locking piece and a lower locking piece are provided. The lower locking piece and the pressure port outer key form a pressure port, and the pressure port is used to engage with the inner key plate; on the inner wall of the tube body of the inner section rod, a plurality of the lower locking pieces are arranged along the telescopic direction of the outer section rod and the inner section rod. The plurality of inner key plates are respectively matched with the plurality of lower locking pieces. The distance between adjacent two inner key plates is equal to the distance between adjacent two lower locking pieces; the width dimensions of the mechanical locking rod slide and the friction rod slide of the inner section rod are the same and correspond to the width of the inner key plate.

2. The drill pipe of the rotary drilling rig according to claim 1, characterized in that, The drill pipe of the rotary drilling rig includes a first rod section (11), a second rod section (13), a third rod section (15) and a fourth rod section (17). The second rod section (13) is telescopically sleeved inside the first rod section (11), the third rod section (15) is telescopically sleeved inside the second rod section (13), and the fourth rod section (17) is telescopically sleeved inside the third rod section (15). The first rod section (11) includes a first pipe body (112), and a first inner key plate (113) is provided on the inner wall of the first pipe body (112). The second rod section (13) includes a second pipe body (132), and a second mechanical locking rod slideway (134) and a second friction rod slideway (135) are provided on the outer wall of the second pipe body (132). The first inner key plate (113) of the first rod section (11) is selectively slidably engaged with the second mechanical locking rod slideway (134) and the second friction rod slideway (135). A second inner key plate (133) is provided on the inner wall of the second pipe body (132) of the second rod section (13). The third rod section (15) includes a third pipe body (152), and a third mechanical locking rod slideway (154) and a third friction rod slideway (155) are provided on the outer wall of the third pipe body (152). The second inner key plate (133) of the second rod section (13) is selectively slidably engaged with the third mechanical locking rod slideway (154) and the third friction rod slideway (155). A third inner key plate (153) is provided on the inner wall of the third pipe body (152). The fourth rod section (17) includes a fourth pipe body (172), and a fourth mechanical locking rod slideway (174) and a fourth friction rod slideway (175) are provided on the outer wall of the fourth pipe body (172). The third inner key plate (153) of the third rod section (15) is selectively slidably engaged with the fourth mechanical locking rod slideway (174) and the fourth friction rod slideway (175).

3. The drill pipe of the rotary drilling rig according to claim 2, characterized in that, The widths of the second mechanical locking rod slideway (134) and the second friction rod slideway (135) of the second rod section (13) are the same and correspond to the width of the first inner key plate (113). The widths of the third mechanical locking rod slideway (154) and the third friction rod slideway (155) of the third rod section (15) are the same and correspond to the width of the second inner key plate (133). The widths of the fourth mechanical locking rod slideway (174) and the fourth friction rod slideway (175) of the fourth rod section (17) are the same and correspond to the width of the third inner key plate (153).

4. The drill pipe of the rotary drilling rig according to claim 2, characterized in that, On the outer wall of the second tube body (132), second middle guiding external keys (137), second full-course guiding external keys (138), and second pressure port external keys (139) are provided at circumferentially spaced intervals. A second machine lock rod slideway (134) is formed between the second middle guiding external key (137) and the second full-course guiding external key (138), and a second friction rod slideway (135) is formed between the second full-course guiding external key (138) and the second pressure port external key (139). On one side of the second pressure port external key (139), a second upper lock piece (141) and a second lower lock piece (142) are provided. The second lower lock piece (142) and the second pressure port external key (139) form a second pressure port (144). At one end of the second tube body (132), a second bottom guiding external key (146) is further provided. The second bottom guiding external key (146) corresponds to the second middle guiding external key (137) in the circumferential direction of the second tube body (132); on the outer wall of the third tube body (152), third middle guiding external keys (157), third full-course guiding external keys (158), and third pressure port external keys (159) are provided at circumferentially spaced intervals. A third machine lock rod slideway (154) is formed between the third middle guiding external key (157) and the third full-course guiding external key (158), and a third friction rod slideway (155) is formed between the third full-course guiding external key (158) and the third pressure port external key (159). On one side of the third pressure port external key (159), a third upper lock piece (161) and a third lower lock piece (162) are provided. The third lower lock piece (162) and the third pressure port external key (159) form a third pressure port (164). At one end of the third tube body (152), a third bottom guiding external key (166) is further provided. The third bottom guiding external key (166) corresponds to the third middle guiding external key (157) in the circumferential direction of the third tube body (152); on the outer wall of the fourth tube body (172), fourth middle guiding external keys (177), fourth full-course guiding external keys (178), and fourth pressure port external keys (179) are provided at circumferentially spaced intervals. A fourth machine lock rod slideway (174) is formed between the fourth middle guiding external key (177) and the fourth full-course guiding external key (178), and a fourth friction rod slideway (175) is formed between the fourth full-course guiding external key (178) and the fourth pressure port external key (179). On one side of the fourth pressure port external key (179), a fourth upper lock piece (181) and a fourth lower lock piece (182) are provided. The fourth lower lock piece (182) and the fourth pressure port external key (179) form a fourth pressure port (184). At one end of the fourth tube body (172), a fourth bottom guiding external key (186) is further provided. The fourth bottom guiding external key (186) corresponds to the fourth middle guiding external key (177) in the circumferential direction of the fourth tube body (172);A plurality of the fourth lower locking pieces (182) arranged along the telescopic direction of the first rod section (11) and the second rod section (13) are provided on the inner wall of the fourth pipe body (172), and a plurality of the third inner key plates (153) arranged along the telescopic direction of the first rod section (11) and the second rod section (13) are provided on the inner wall of the third pipe body (152) of the third rod section (15). The plurality of the third inner key plates (153) are respectively matched with the plurality of the fourth lower locking pieces (182).; 5. The drill pipe of the rotary drilling rig according to claim 2, characterized in that, A first mechanical locking rod slideway (114) and a first friction rod slideway (115) are provided on the outer wall of the first pipe body (112). One of the first mechanical locking rod slideway (114) and the first friction rod slideway (115) is used to cooperate with the inner key on the inner side wall of the power head to connect the first rod section (11) with the power head.

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