Double-pipe drilling tool for geotechnical engineering

Abstract

The utility model relates to a double-pipe drilling tool for geotechnical engineering. Comprising an outer pipe and an inner pipe, a clamping base is detachably connected to the lower end face of the outer pipe and is of a cylindrical rotating body structure internally provided with a coring cavity, the inner pipe is arranged in the coring cavity in a matched mode, internal threads are arranged in the upper end of the coring cavity, drilling teeth are arranged on the lower end face of the clamping base, and a gap is reserved between the outer side wall of the inner pipe and the inner side wall of the outer pipe. A clamping part is arranged on the outer side wall of the clamping seat at the upper ends of the drill teeth; the clamping part comprises an upper connecting part and a lower connecting part, the diameter of the upper connecting part is 108mm, and the diameter of the lower connecting part is 101mm. According to the utility model, the clamping part is arranged on the outer side wall of the clamping seat, so that the clamping seat can be matched with different types of free pliers through different diameters, the clamping seat is more convenient and stable to disassemble and assemble, but the arranged clamping part can influence the scouring backflow of slurry on the outer side wall of the clamping seat of the double-pipe drilling tool; therefore, the additionally arranged discharge part can accelerate the flow of the slurry in the rotating process of the outer pipe.

Description

Technical Field

[0001] The utility model belongs to the field of double-tube drill tools, and particularly relates to a double-tube drill tool for geotechnical engineering. Background Art

[0002] In geotechnical engineering, a double-tube drill tool is a single-action double-tube drill tool in which the outer tube rotates while the inner tube does not rotate during the drilling process. Since the single-action double-tube drill tool avoids the mechanical crushing of rock cores caused by frictional vibration generated by the rotation of the drill tool, the core-taking quality is high. The clamping seat of the double-tube drill tool is connected to the bottom of the inner tube. After the drilling and core-taking are completed, the clamping seat needs to be disassembled. In actual operations, especially in the 101-bit, after each core is taken, the bit needs to be disassembled. However, many inexperienced masters on-site directly use a 108-free pliers for disassembly and assembly. Because of the 7-mm difference, the three teeth of the free pliers are not 120° on the outer circle of the bit. When the bit thread is very tight, the force is uneven, which will cause the bit to deform during the disassembly and assembly process and affect the next operation. Since the 101-bit is a special bit, it is not necessarily equipped with a complete set of free pliers on-site, which will cause deformation and damage of the inappropriate free pliers when disassembling the clamping seat. Content of the Utility Model

[0003] To solve the above technical problems, the utility model provides a double-tube drill tool for geotechnical engineering. By providing a clamping portion on the outer side wall of the clamping seat, free pliers of different models can be adapted through different diameters, making the disassembly and assembly of the clamping seat more convenient and stable. However, the provided clamping portion will affect the flushing and reflux of the mud on the outer side wall of the clamping seat of the double-tube drill tool. Therefore, the added discharging portion can accelerate the flow of the mud during the rotation of the outer tube.

[0004] To achieve the above object, the technical solution adopted by the utility model is:

[0005] A double-tube drill tool for geotechnical engineering, comprising an outer tube and an inner tube. The lower end surface of the outer tube is detachably connected with a clamping seat. The clamping seat is a cylindrical rotating body structure with a core-taking cavity inside. The inner tube is fitted in the core-taking cavity. An internal thread is provided in the upper end portion of the core-taking cavity. Drill teeth are provided on the lower end surface of the clamping seat. A gap is left between the outer side wall of the inner tube and the inner side wall of the outer tube. A clamping portion is provided on the outer side wall of the clamping seat above the drill teeth. The clamping portion includes an upper connecting portion and a lower connecting portion. The diameter of the upper connecting portion is 108 mm, and the diameter of the lower connecting portion is 101 mm.

[0006] On the outer sidewall of the socket, there is also a discharge section. The discharge section is arranged at the upper end of the clamping section. The diameter of the discharge section is larger than that of the clamping section, and the diameter of the discharge section is smaller than the diameter of the drill teeth. On the outer sidewall of the discharge section, there is a discharge groove, which spirally penetrates the discharge section from bottom to top in a clockwise direction. On the outer sidewall of the discharge section, there is also a diversion groove, which spirally penetrates the discharge section from bottom to top in a counterclockwise direction.

[0007] For the double-tube drill for geotechnical engineering adopting this structure, the outer tube and the inner tube are the conventional settings of the double-tube drill. The socket connected to the lower end of the outer tube is fixed by setting internal threads at the upper end of the core-taking cavity of the socket, and the internal threads are engaged with the external threads at the lower end of the outer tube. In order to facilitate the disassembly of the socket, a clamping section is arranged on the outer sidewall of the socket, which is composed of an upper connecting part and a lower connecting part. The diameter of the upper connecting part is 108 mm, and the diameter of the lower connecting part is 101 mm. 108 is a relatively common drill bit size, and there is a large amount of use of 108 free clamps and the tools are also relatively commonly used in drilling operations. Therefore, the provided upper connecting part can be disassembled by taking the commonly used 108 free clamp when the socket needs to be disassembled, while the provided lower connecting part needs to be disassembled by a 101 free clamp. After all, this socket is a 101 drill bit. When the construction team in geotechnical engineering takes the 101 drill bit as the commonly used tool, a 101 free clamp will be provided for disassembly and use. Therefore, the clamping section composed of the upper connecting part and the lower connecting part can be applicable to at least two different specifications of free clamps, so that all three teeth of the free clamp can catch the socket at an angle of 120° during the disassembly of the socket, making the process of disassembling the socket more stable, avoiding deformation and damage of the socket, and reducing the cost of tools.

[0008] Then, the clamping section will inevitably cause a certain degree of gap at the upper end of the drill teeth. Since the double-tube drill needs to flow the mud through the gap between the outer tube and the inner tube during operation, and after flowing through the lower drilling area, it returns to the ground, which can reduce the erosion of the mud on the core, improve the recovery rate, the inner tube protects the core, improves the integrity of the core, and maintains the original state of the lithology. Therefore, the upward return flow of the mud will be affected by the gap of the clamping section. In order to ensure the fluidity of the mud, a discharge section is added at the upper end of the clamping section. The discharge section is composed of a discharge groove and a diversion groove. The discharge groove spirally penetrates the discharge section from bottom to top in a clockwise direction, and the diversion groove spirally penetrates the discharge section from bottom to top in a counterclockwise direction. Therefore, during the rotation of the outer tube, the clamping section will also rotate simultaneously. The discharge groove and the diversion groove with different spiral rotations will pump the mud from the bottom to the top, accelerating the flow rate of the mud at the lower end, thereby increasing the fluidity of the mud and ensuring the integrity of the drilled core.

[0009] Furthermore, the cross-sectional size of the discharge groove is larger than that of the diversion groove.

[0010] Compared with the prior art, the utility model has the advantages that: through the setting of the clamping part, at least two free pliers of different specifications can be used, so that in the process of disassembling the clamping seat, the three teeth of the free pliers can clamp the clamping seat at an angle of 120°, making it more stable during the process of disassembling the clamping seat, avoiding deformation and damage of the clamping seat, and reducing the cost of tools. In addition, the gap formed by the clamping part, through the setting of the discharge part, presents a discharge groove and a guide groove with different spiral rotations, and the rotation of the discharge groove and the guide groove is also driven during the rotation of the clamping seat, and the mud is pumped from the bottom to the top, so that the mud flow rate at the lower end is accelerated, thereby increasing the fluidity of the mud and ensuring the integrity of the drilling core. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0012] Figure 1 It is a three-dimensional diagram of the utility model;

[0013] Figure 2 This is a bottom-up explosion diagram of the utility model;

[0014] Figure 3 It is a top exploded schematic diagram of the utility model.

[0015] Among them: 1. outer tube; 2. inner tube; 3. holder; 31. coring cavity; 32. internal thread; 33. drill teeth; 34. clamping part; 341. upper connecting part; 342. lower connecting part; 35. discharge part; 351. discharge groove; 352. guide groove. DETAILED DESCRIPTION

[0016] In order to make the purpose, technical solution and advantages of the utility model clearer, the technical solution of the utility model will be described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work belong to the scope of protection of the utility model.

[0017] The specific implementation of the utility model will be described below in conjunction with the accompanying drawings:

[0018] like Figures 1-3As shown in the figure, a double-tube drill for geotechnical engineering includes an outer tube 1 and an inner tube 2. A clamping seat 3 is detachably connected to the lower end face of the outer tube 1. The clamping seat 3 is a cylindrical rotating body structure with a core-taking cavity 31 inside. The inner tube 2 is fitted in the core-taking cavity 31. An internal thread 32 is provided in the upper end part of the core-taking cavity 31. Drill teeth 33 are provided on the lower end face of the clamping seat 3. A gap is left between the outer side wall of the inner tube 2 and the inner side wall of the outer tube 1. A clamping portion 34 is provided on the outer side wall of the clamping seat 3 above the drill teeth 33. The clamping portion 34 includes an upper connecting portion 341 and a lower connecting portion 342. The diameter of the upper connecting portion 341 is 108 mm, and the diameter of the lower connecting portion 342 is 101 mm.

[0019] A material discharging portion 35 is further provided on the outer side wall of the clamping seat 3. The material discharging portion 35 is arranged above the clamping portion 34. The diameter of the material discharging portion 35 is larger than that of the clamping portion 34, and the diameter of the material discharging portion 35 is smaller than that of the drill teeth 33. A material discharging groove 351 is provided on the outer side wall of the material discharging portion 35. The material discharging groove 351 spirally penetrates the material discharging portion 35 from bottom to top in a clockwise direction. A diversion groove 352 is further provided on the outer side wall of the material discharging portion 35. The diversion groove 352 spirally penetrates the material discharging portion 35 from bottom to top in a counterclockwise direction.

[0020] Furthermore, the cross-sectional size of the material discharging groove 351 is larger than that of the diversion groove 352.

[0021] Description of the working mode of the present utility model:

[0022] The double-tube drill tool for geotechnical engineering adopting this structure has the outer tube 1 and the inner tube 2 as the conventional settings of the double-tube drill tool. A clamping seat 3 is connected to the lower end of the outer tube 1. By arranging an internal thread 32 at the upper end of the core-taking cavity 31 of the clamping seat 3, the internal thread 32 engages with the external thread at the lower end of the outer tube 1, thus playing a role in fixing the clamping seat 3. In order to facilitate the disassembly of the clamping seat 3, a clamping portion 34 is arranged on the outer side wall of the clamping seat 3, which is composed of an upper connecting portion 341 and a lower connecting portion 342. The diameter of the upper connecting portion 341 is 108 mm, and the diameter of the lower connecting portion 342 is 101 mm. 108 is a relatively common drill bit size, and there is a relatively large amount of use of the 108 free pliers and the tool is also relatively commonly used in drilling operations. Therefore, when it is necessary to disassemble the clamping seat 3, the provided upper connecting portion 341 can be disassembled by taking the commonly used 108 free pliers, while the provided lower connecting portion 342 needs to be disassembled by the 101 free pliers. After all, the clamping seat 3 is a 101 drill bit. When the construction team in geotechnical engineering takes the 101 drill bit as the commonly used tool, the 101 free pliers will be provided for disassembly and use. Therefore, the clamping portion 34 composed of the upper connecting portion 341 and the lower connecting portion 342 can be applicable to at least two different specifications of free pliers, so that all three teeth of the free pliers can catch the clamping seat 3 at an angle of 120° during the process of disassembling the clamping seat 3, making the process of disassembling the clamping seat 3 more stable, avoiding deformation and damage of the clamping seat 3, and reducing the tool cost.

[0023] Then the provided clamping portion 34 will inevitably cause a certain degree of gap at the upper end of the drill tooth 33. Since during the working process of the double-tube drill tool, mud needs to flow in from the gap between the outer tube 1 and the inner tube 2, flow through the lower drilling area and then return to the ground, which can reduce the erosion of the mud on the core, improve the recovery rate, the inner tube 2 protects the core, improves the integrity of the core, and maintains the original state of the lithology. Therefore, the upward flowing liquidity of the mud will be affected by the gap of the clamping portion 34. In order to ensure the liquidity of the mud, a discharging portion 35 is added at the upper end of the clamping portion 34. The discharging portion 35 is composed of a discharging groove 351 and a guiding groove 352. The discharging groove 351 spirally penetrates the discharging portion 35 from bottom to top in a clockwise direction, and the guiding groove 352 spirally penetrates the discharging portion 35 from bottom to top in a counterclockwise direction. Therefore, during the rotation of the outer tube 1, the clamping portion 34 will also rotate simultaneously. The discharging groove 351 and the guiding groove 352 with different spiral rotations will pump the mud from below to above. In order to stagger the upward flowing liquidity of the mud, the cross-sectional size of the discharging groove 351 is set to be larger than that of the guiding groove 352. Therefore, the mud flow rate at the lower end is accelerated, thereby increasing the liquidity of the mud and ensuring the integrity of the drilled core.

[0024] The beneficial effects of the present utility model are as follows: Through the setting of the clamping portion 34, at least two different specifications of free pliers can be applied, so that all three teeth of the free pliers can catch the card seat 3 at an angle of 120° during the process of disassembling the card seat 3, making the process of disassembling the card seat 3 more stable, avoiding deformation and damage of the card seat 3, and reducing the cost of tools. In addition, for the gap formed by the clamping portion 34, by setting the feeding portion 35, the feeding grooves 351 and the diversion grooves 352 with different spiral rotations are presented. During the rotation of the card seat 3, the feeding grooves 351 and the diversion grooves 352 are also driven to rotate, pumping the mud from the lower part to the upper part, accelerating the flow rate of the mud at the lower end, thereby increasing the fluidity of the mud and ensuring the integrity of the drilling core.

[0025] The above embodiments are only used to illustrate the technical solutions of the present utility model, rather than to limit it; although the present utility model has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or equivalently replace some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present utility model.

Claims

1. A double-tube drilling tool for geotechnical engineering, characterized in that: It comprises an outer tube and an inner tube, the lower end face of the outer tube is detachably connected with a holder, the holder is a cylindrical rotating body structure with a core taking cavity inside, the inner tube fits in the core taking cavity, an internal thread is provided in the upper end part of the core taking cavity, a drill tooth is provided on the lower end face of the holder, a gap is left between the outer side wall of the inner tube and the inner side wall of the outer tube, and a clamping part is provided on the outer side wall of the holder at the upper end of the drill tooth.

2. The double-tube drilling tool for geotechnical engineering according to claim 1, characterized in that: The clamping portion includes an upper connecting portion and a lower connecting portion, the diameter of the upper connecting portion is 108 mm, and the diameter of the lower connecting portion is 101 mm.

3. The double-tube drilling tool for geotechnical engineering according to claim 1, characterized in that: A discharge portion is also provided on the outer side wall of the clamping seat. The discharge portion is arranged at the upper end of the clamping portion. The diameter of the discharge portion is larger than the diameter of the clamping portion, and the diameter of the discharge portion is smaller than the diameter of the drill tooth.

4. The double-tube drilling tool for geotechnical engineering according to claim 3, characterized in that: A discharge groove is arranged on the outer side wall of the discharge part, and the discharge groove is in a clockwise spiral shape and penetrates the discharge part from bottom to top.

5. The double-tube drilling tool for geotechnical engineering according to claim 4, characterized in that: A guide groove is also provided on the outer side wall of the discharge part, and the guide groove is in a counterclockwise spiral shape and penetrates the discharge part from bottom to top.

6. The double-tube drilling tool for geotechnical engineering according to claim 5, characterized in that: The cross-sectional size of the discharge groove is larger than the cross-sectional size of the guide groove.

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