Rock core clamping protection mechanism

Abstract

The utility model relates to a rock core clamping protection mechanism, which comprises a clamp spring seat and a telescopic clamp spring, the clamp spring seat is cylindrical, a plurality of guide grooves which vertically penetrate downwards are arranged on the lower portion of the side wall of the clamp spring seat, the guide grooves are arranged on the clamp spring seat in a surrounding mode, a steel ring is horizontally arranged on the inner side of the lower end of each guide groove in a surrounding mode, and the telescopic clamp spring comprises a steel ring and a clamp spring piece. The clamping spring sheets are arranged on the steel ring, the multiple clamping spring sheets correspond to the guide grooves and are arranged on the steel ring in a surrounding mode, the steel ring is arranged in the clamping spring base and can slide up and down along the clamping spring base, the clamping spring sheets can slide up and down along the guide grooves, and the lower ends of the clamping spring sheets extend out of the steel ring. According to the utility model, the core recovery rate is improved, the core is prevented from falling off, and the core disturbance degree is reduced.

Description

Technical Field

[0001] The utility model relates to the field of geological engineering and technology, and in particular to a core clamping and protecting mechanism. Background Art

[0002] However, in recent years, the output has not reached a corresponding scale in the process of continuous expansion of development scale, which also reflects that the previous exploration results cannot meet the requirements of later development investment. According to the current status of Quaternary exploration in the mining areas of Qarhan Salt Lake, Yiliping, East and West Taijinaier in recent years, insufficient coring rate, hole collapse and scrapping, and hydrological wells have become the main problems restricting the quality of salt lake resource exploration and exploration tasks.

[0003] Through follow-up investigation, it was found that in order to avoid dissolution of the salt layer, a pumpless drilling method was adopted during the drilling process. When drilling in formations with plasticity and fluidity characteristics, ordinary single-action double-tube coring drill bits not only have a low coring rate, but also the ordinary inner tube retaining spring cannot ensure that the residual core does not fall off during the process of pulling out the drill bit. Utility Model Content

[0004] The utility model provides a core clamping protection mechanism to solve the technical problems existing in the background technology. The utility model improves the core recovery rate and prevents the core from falling off.

[0005] The technical solution of the utility model is: the utility model is a core clamping protection mechanism, which is special in that: the core clamping protection mechanism comprises a retaining spring seat and a telescopic retaining spring, the retaining spring seat is cylindrical, and a guide groove vertically penetrates downward at the lower part of the side wall, there are multiple guide grooves, which are arranged around the retaining spring seat, a steel ring is arranged horizontally around the inner side of the lower end of the guide groove, the telescopic retaining spring comprises a steel ring and a retaining spring sheet, the retaining spring sheet is arranged on the steel ring, there are multiple retaining spring sheets corresponding to the guide groove, which are arranged around the steel ring, the steel ring is arranged in the retaining spring seat, and can slide up and down along the retaining spring seat, the retaining spring sheet can slide up and down along the guide groove, and the lower end extends outside the steel ring.

[0006] Furthermore, a plurality of slots are arranged around the outer wall of the steel ring, and the arrangement position is consistent with the guide slot position. A through hole is arranged in the middle of the slot. The upper end of the retaining spring is embedded in the steel ring slot and connected to the steel ring through the steel ring rivet and the through hole.

[0007] Furthermore, the spring sheet is a spring sheet with an arc.

[0008] Furthermore, a plurality of guide grooves are evenly distributed on the retaining spring seat, and a plurality of retaining spring sheets are evenly distributed on the steel ring.

[0009] The utility model designs a core clamping protection mechanism item by item through analyzing factors such as the pumping mechanism of a pumpless adapter, the timeliness and effect of a single-action mechanism, the elasticity of a spring-cage mechanism, the principle of a spring-cage seat to prevent core shedding, the inner and outer annular spaces between a drill bit and a drill tool, and adaptability. In a specific application embodiment of the utility model, a total of five sets of mechanisms are composed, namely, a reducer adapter assembly, an outer tube assembly mechanism, a spring-cage single-action mechanism, a local reverse circulation mechanism, and a core clamping protection mechanism. The reducer assembly includes a reducer, a hole expansion washer, and a drill pipe reducer; the outer tube component includes an outer tube and a drill bit; the spring-cage single-action mechanism includes a spring-cage adjustment screw, a spring-cage adjustment nut, an upper support platform of the spring-cage cavity, a spring-cage cavity, a spring-cage receiver, a spring, a spring-cage cavity pressure bearing, a lower support platform of the spring-cage cavity, a rolling bearing, an upper pressure bearing of the single-action cavity, a single-action cavity, a single-action cavity transmission shaft, a lower support platform of the single-action cavity, and a lower pressure bearing of the single-action cavity; the local reverse circulation mechanism includes a locking nut, an inner tube receiver, a reverse circulation mechanism, and an inner tube; the core clamping protection mechanism includes a retaining spring seat and a telescopic retaining spring. The utility model first connects the spring card single action mechanism, the local reverse circulation mechanism and the inner tube in sequence to form an inner tube assembly; secondly, after the core clamping protection mechanism is installed into the upper end of the inner step of the drill bit, the outer tube and the drill bit are connected to form an outer tube assembly; the inner tube assembly and the outer tube assembly are connected to the reducer assembly to form a complete set of drilling tools, and the installation order of the reducer assembly is as follows: the hole expansion washer is sleeved on the outer ring of the reducer of the drill rod of the drilling tool and then the reducer is connected; finally, the assembled drilling tool is connected to the active drill rod and then vertically hoisted, and the inner tube and the core clamping protection mechanism are observed from below the drill bit. The contact condition of the protection mechanism is that before drilling, the lower end of the inner tube is in the core clamping protection mechanism, and the distance from the telescopic retaining spring is 1.5-2cm. Otherwise, the clearance of the inner tube assembly is corrected by adjusting the spring-cage adjusting screw, and then drilling is started; before lifting the drill, a slight pier drilling is performed, that is, the drill bit is raised by 10cm and then quickly lowered to the bottom of the hole, so that the inner tube assembly pushes the telescopic retaining spring of the core clamping protection mechanism to the lower end of the retaining spring seat to restore it to the original curvature. The designed telescopic retaining spring has better strength and curvature than ordinary grabbing springs, which meets the purpose of retaining spring retaining to clamp the core. The inner tube and the outer tube are standard geological pipes of the same series, and the length can be adjusted according to actual needs. The utility model is matched with conventional drill rods and drill bits, and is suitable for formations with plasticity and fluidity characteristics in salt lake drilling. The utility model can not only meet the purpose of destroying the original state of the core during drilling, but also meet the purpose of preventing the core from falling off during the drilling process. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a structural schematic diagram of the utility model;

[0011] Figure 2 It is a structural schematic diagram of an application embodiment of the utility model;

[0012] Figure 3 This is a schematic diagram of the structure of a single-acting cavity transmission shaft in an application embodiment of the utility model;

[0013] Figure 4 It is a structural schematic diagram of a local reverse circulation mechanism in an application embodiment of the utility model.

[0014] The following are the descriptions of the reference numerals:

[0015] 1. Spring-clip adjusting screw; 2. Reducer adapter; 3. Hole expansion washer; 4. Reducer adapter for drilling tool and drill pipe; 5. Spring-clip adjusting nut; 6. Upper support platform of spring-clip chamber; 7. Spring-clip chamber; 8. Spring-clip adapter; 9. Spring; 10. Pressure bearing of spring-clip chamber; 11. Lower support platform of spring-clip chamber; 12. Rolling bearing; 13. Upper pressure bearing of single-action chamber; 14. Single-action chamber; 15. Transmission shaft of single-action chamber; 16. Lower support platform of single-action chamber; 17. Lower pressure bearing of single-action chamber; 18. Locking nut; 19. Inner tube adapter; 20. Through screw; 21. Filter locking mechanism; 22. Inner tube; 23. Core clamping protection mechanism; 24. Circlip seat; 25. Inner step of drill bit; 26. Outer tube; 27. Telescopic circlip;

[0016] 15.1, locking pin position; 15.2, single-action chamber upper pressure bearing and rolling bearing sleeve position; 15.3, upper step load-bearing position; 15.4, lower step load-bearing fixed position; 15.5, single-action chamber lower pressure bearing sleeve fixed position; 15.6, local reverse circulation inner pipe connection position; 15.7, channel; 15.8, steel ball;

[0017] 21.1. Filter cup cover; 21.2. Filter cup body;

[0018] 24.1, guide groove; 24.2, steel ring;

[0019] 27.1. Steel ring; 27.2. Reed clip. DETAILED DESCRIPTION

[0020] The present invention will be described in further detail below in conjunction with the accompanying drawings and specific embodiments.

[0021] See also Figure 1 The structure of the specific embodiment of the utility model includes a spring holder 24 and a telescopic spring 27. When coring (single-tube pier drilling, that is, the main winch brake is released after the drill is pulled up 10 cm from the bottom of the hole to make the drill fall freely), the spring mechanism and the lower structure are integrally ejected, and the telescopic spring 27 is pushed down to clamp the core, and the spring sheet shrinks like a grab to prevent the core from falling off;

[0022] The spring seat 24 is cylindrical, and can be made of steel pipe. Its outer diameter is slightly smaller than the inner diameter of the drill bit rigid body, and its height is about 12 cm. Its structure is lantern-shaped, and it is divided into three parts from top to bottom, that is, the upper part is about 3 cm high, and the inner diameter is slightly larger than the outer diameter of the inner tube 22. When drilling normally, the lower end of the inner tube 22 is located in the upper part of the spring seat 24; the inner diameter of the middle part is slightly larger than the outer diameter of the inner tube 22, the height is about 5 cm, and it is evenly distributed vertically along the steel pipe wall, and the guide grooves 24.1 are opened downward (with a width of about 1 cm and the inner and outer walls are open). The number and layout of the guide grooves 24.1 are consistent with the spring sheet 27.2; the inner diameter of the lower part is consistent with the inner diameter of the inner tube 22, and a steel ring 24.2 is arranged inside the lower end guide (the lower end of the guide groove 24.1); the telescopic spring 27 includes a steel ring 27. 1 and a spring plate 27.2, the inner diameter of the steel ring 27.1 is larger than the inner diameter of the inner tube 22, the outer diameter is smaller than the inner diameter of the upper part of the spring seat 24, and the height is about 1cm; a groove is provided on the outer wall of the steel ring 27.1 (the depth is consistent with the thickness of the spring plate 27.2, the opening position is consistent with the position of the guide groove 24.1, the width is 8mm, the upper end of the spring plate 27.2 is embedded in the groove of the steel ring 27.1, the spring plate is selected with an arc, a through hole is provided in the middle of the groove, the upper end of the spring plate 27.2 is embedded in the groove of the steel ring 27.1, and is connected with the groove through the steel ring rivet and the through hole, the length is greater than 7cm, the thickness is 0.7mm, and the width is 8mm. The spring plate 27.2 can slide up and down along the guide groove 24.1, and the lower end extends outside the steel ring 24.2.

[0023] See also Figure 2 , 3. The mechanism of the specific embodiment of the application of the utility model includes a reducer assembly, a spring card single-action mechanism, a local reverse circulation mechanism, a core clamping protection mechanism and an outer tube 26. The reducer assembly, the spring card single-action mechanism and the local reverse circulation mechanism are arranged in the outer tube from top to bottom. The reducer assembly includes a reducer 2, a hole expansion washer 3 and a drill rod reducer 4. The reducer 2 has a hollow structure inside, and the inner side of the upper end is a positive thread female buckle. The outer diameter of the upper end is consistent with the outer diameter of the outer tube 26. The outer diameter of the middle position of the hand 2 is smaller than the inner diameter of the reaming washer 3, and the length is consistent with the height of the reaming washer 3. The outer side of the lower end is a positive thread male buckle, and the buckle type is consistent with the female buckle at the upper end of the drill pipe reducer 4 of the drilling tool; the inside of the reaming washer 3 is a hollow structure, which is arranged around the middle position of the reducer 2, and the outer diameter is consistent with the outer diameter of the outer tube 21. The reaming washer 3 is vertically evenly arranged with 4 alloy blocks, which are inserted into the middle position of the drill pipe reducer 4 of the drilling tool for the purpose of reaming and straightening. The reaming washer 3 is located on the outer side of the upper end of the outer tube 16. The drill pipe reducer 4 of the drilling tool is a hollow structure, and a positive thread female buckle is provided on the inner side of the upper end to connect to the lower end of the reducer 2, and the outer diameter of the upper end is consistent with the outer diameter of the outer tube 26. The outer side of the lower end is a positive thread male buckle, which is connected to the spring card single-action mechanism.

[0024] The spring-cage single-action mechanism includes a spring-cage adjusting screw 1, a spring-cage adjusting nut 5, an upper support platform 6 of the spring-cage cavity, a spring-cage cavity 7, a spring-cage takeover 8, a spring 9, a spring-cage cavity pressure bearing 10, a spring-cage cavity lower support platform 11, a rolling bearing 12, a single-action cavity upper pressure bearing 13, a single-action cavity 14, a single-action cavity transmission shaft 15, a single-action cavity lower support platform 16 and a single-action cavity lower pressure bearing 17. The upper part of the spring-cage adjusting screw 1 passes through the reducer takeover assembly, and the lower end is connected to the spring-cage takeover 8. The buckle type of the spring-cage adjusting nut 5 is consistent with that of the spring-cage adjusting screw 1 and is installed on the spring-cage adjusting screw 1; the spring-cage cavity 7 is a hollow structure, and the inner sides of the upper and lower ends are both positive thread female buckles. The upper positive thread female buckle is connected to the lower male buckle of the drill rod reducer 4, and the lower positive thread female buckle is connected to the spring-cage cavity lower support platform 11. The inner diameter is larger than the outer diameter of the spring 9; the inner diameter of the drill rod reducer 4 is larger than the outer diameter of the upper end of the spring card receiver 8; the lower support 11 of the spring card cavity is an inverted T-shaped structure with a hollow structure inside. The outer side of the upper end is a positive thread male buckle, which is connected to the positive thread female buckle at the lower end of the spring card cavity 7. The outer diameter of the lower end is consistent with the outer diameter of the spring card cavity 7. The inner diameter of the lower support 11 of the spring card cavity is larger than the outer diameter of the upper connecting shaft of the spring card receiver 8 and smaller than the inner diameter of the spring 9 and the pressure bearing 10 of the spring card cavity. The pressure bearing 10 of the spring card cavity is arranged at the upper end of the lower support 11 of the spring card cavity, and is located in the spring card cavity 7; the spring card receiver 8 is installed at the lower end of the lower support 11 of the spring card cavity, and is divided into three parts: upper, middle and lower. The upper part is a connecting shaft, which runs through the spring card cavity 7, and its outer diameter is smaller than the inner diameter of the spring 9. A positive thread female buckle is provided at the upper end and connected to the spring card adjusting screw 1 , the spring 9 is arranged around the outside of the connecting shaft, the outer diameter of the middle part is consistent with the outer diameter of the lower support platform 11 of the spring card cavity, and the inner side of the lower end is a positive thread male buckle, which is connected to the upper end of the single-action cavity 14; the upper support platform 6 of the spring card cavity is a T-shaped structure, and the interior is a hollow structure, the inner diameter is larger than the outer diameter of the spring card adjusting screw 1, the outer outer diameter of the upper end is smaller than the inner diameter of the spring card cavity 7, and the outer outer diameter of the lower end is smaller than the inner diameter of the spring 9; the spring 9 is stuck between the upper support platform 6 of the spring card cavity and the lower support platform 11 of the spring card cavity, the spring card adjusting screw 1 passes through the upper support platform 6 of the spring card cavity, and the outer thread of the lower end is connected with the positive thread female buckle on the inner side of the upper end of the connecting shaft; the interior of the single-action cavity 14 is a hollow structure with an outer diameter smaller than the outer diameter of the spring card cavity 7, and both the upper and lower ends are positive thread female buckles. The single-action cavity 14 is provided with two inner steps from top to bottom, and the inner diameters and heights of the two inner steps are respectively Corresponding to the two outer steps of the single-acting cavity transmission shaft 15, in order to achieve the purpose of straightening and preventing the single-acting cavity transmission shaft 15 from moving up and down, an oil injection nozzle or oil injection window is provided below the upper thread of the single-acting cavity 14; the single-acting cavity transmission shaft 15 is divided into six parts from top to bottom: a locking pin part 15.1 (this part is provided with a positive thread male buckle and a horizontal through hole is dug for installing a locking nut and connecting and fixing the lower end of the spring card adapter), a single-acting cavity upper pressure bearing and rolling bearing sleeve part 15.2 (the outer diameter of this part is equal to the inner diameter of the single-acting cavity upper pressure bearing 13 and rolling bearing 12, the rolling bearing 12 is sleeved into the upper end of the single-acting cavity upper pressure bearing and rolling bearing sleeve part, and the single-acting cavity upper pressure bearing 13 is sleeved into the lower end of the single-acting cavity upper pressure bearing and rolling bearing sleeve part), and an upper step load-bearing part 15.3. Lower step load-bearing fixed position 15.4 (upper step load-bearing position 15.3, lower step load-bearing fixed position 15.4 correspond to the positions of the two inner steps in the single-moving chamber 14), single-moving chamber lower pressure bearing sleeve fixed position 15.5 (the outer diameter of this position is equal to the inner diameter of the single-moving chamber lower pressure bearing 17, and the single-moving chamber lower pressure bearing sleeve fixed position 15.5), local reverse circulation inner pipe connection position 15.6 (this position is for connecting the inner The key part of the pipe joint 19 and the local reverse circulation mechanism is provided with a positive thread male buckle on the outside, a hole 15.7 is vertically provided at the center of the inside, and a steel ball is provided in the hole 15.7. An exhaust hole connected to the hole 15.7 is horizontally provided at the upper end of the local reverse circulation inner pipe connection part, and the exhaust hole diameter is smaller than the steel ball diameter.); the single-action cavity lower support 16 is an inverted T-shaped structure with a hollow structure inside, passing through the lower end of the single-action cavity transmission shaft 15, and the positive thread male buckle at the upper end is connected to the lower end of the single-action cavity 14.

[0025] See also Figure 4The local reverse circulation mechanism includes a locking nut 18, an inner tube adapter 19, a filter locking mechanism 21 and an inner tube 22; the locking nut 18 is composed of a nut and a stop washer, and is installed on the outer positive thread male buckle at the lower end of the single-acting cavity transmission shaft 15 to adjust the gap of the inner tube 22; the inner tube adapter 19 is a T-shaped structure with a hollow structure inside, and a positive thread female buckle is provided on the inner side, which is connected to the outer positive thread male buckle at the lower end of the single-acting cavity transmission shaft 15, located below the locking nut 18, and a positive thread male buckle is provided on the outer side of the lower end of the inner tube adapter 19 for connecting Inner tube 22; filter screen locking mechanism 21 includes a through screw 20, a filter cup cover 21.1, a filter cup body 21.2 and a filter screen, which mainly plays the role of filtering gravel to prevent gravel from clogging the exhaust hole; the through screw 20 is hollow inside, the inner diameter is smaller than the diameter of the steel ball, and the outer side is all positive thread male buckle, the buckle type is consistent with the inner female buckle of the lower end of the single-action cavity transmission shaft 15, and is connected to the lower end of the single-action cavity transmission shaft 15; the outer diameter of the filter cup body 21.2 is smaller than the inner diameter of the inner tube 22, the interior is hollowed out, and the outer side is provided with a positive thread female buckle, depth The inner bottom of the filter cup body 21.2 is flat and has a concentric water hole. The diameter of the water hole is half of the inner diameter of the filter cup body 21.2. The outer diameter of the filter cup cover 21.1 is consistent with the inner diameter of the filter cup body 21.2. The inner side of the filter cup cover 21.1 is all positive thread male buckles (the buckle type is consistent with the positive thread female buckle on the outer side of the cup body). The filter cup body 21.2 is set in the filter cup cover 21.1 and is connected to the filter cup cover 21.1 by thread. A concentric water hole is arranged in the center axis direction, and the inner diameter of the water hole is consistent with the outer diameter of the through screw 20. A positive thread female buckle is arranged on the inner side of the water hole to connect with the positive thread male buckle on the outer side of the through screw 20. The fineness of the filter screen is determined according to the sand content of the water in the borehole and the solid content of the mud. Generally, 160 mesh or 200 mesh is selected. The diameter of the filter screen is consistent with the inner diameter of the filter cup body 21.2 and is installed between the filter cup body 21.2 and the filter cup cover 21.1. The inner tube 22 adopts a conventional inner tube, the upper end of which is connected to the inner tube handle 16, and the lower end is connected to the core clamping protection mechanism.

[0026] When installing the application embodiment of the utility model, first install the single-acting mechanism, install the rolling bearing 12 on the single-acting cavity transmission shaft 15 from top to bottom, install the single-acting cavity transmission shaft 15 with the rolling bearing 12 installed into the single-acting cavity 14 from top to bottom, install the single-acting cavity upper pressure bearing 13 into the single-acting cavity 14 from bottom to top, lock the pressure bearing top screw after the single-acting cavity upper pressure bearing 13 is in place, penetrate the single-acting cavity lower pressure bearing 17 from bottom to top to the lower step load-bearing fixed position 15.4 of the single-acting cavity transmission shaft 15, connect the single-acting cavity lower support platform 16 to the lower end of the single-acting cavity 14, and lock the upper end of the single-acting cavity transmission shaft 15 with a locking nut. At this time, the single-acting mechanism has been installed (pay attention to observe whether the exhaust hole of the single-acting cavity transmission shaft 15 below the single-acting cavity lower support platform 16 is exposed. If it is exposed, the installation is normal, otherwise adjust it).

[0027] Secondly, install the local reverse circulation mechanism at the lower end of the single-acting chamber 14, rotate the locking nut 18 to the hollow top below the single-acting chamber transmission shaft 15, install and screw the inner tube adapter 19 to the lower end of the locking nut 18, install the through-core screw 20 to the lowest part of the single-acting chamber transmission shaft 15, put the filter into the filter cup body 21.2, tighten the filter cup cover 21.1 onto the filter cup body 21.2 to lock the filter, install the through-core screw 20 on the upper end of the filter cup cover 21.1, connect the inner tube 22 to the inner tube adapter 19, and the local reverse circulation mechanism is installed.

[0028] Then install the spring-cage mechanism at the upper end of the single-action mechanism, connect the male buckle at the lower end of the spring-cage receiver 8 to the female buckle at the upper end of the single-action chamber 14, insert the lower support platform 11 of the spring-cage chamber into the column of the spring-cage receiver 8, and thread the spring-cage chamber 7 to the lower support platform 11 of the spring-cage chamber. Then, install the spring-cage chamber pressure bearing 10 and the spring 9 into the spring-cage chamber 7 respectively, buckle the upper support platform 6 of the spring-cage chamber into the spring-cage chamber 7, press the upper support platform 6 of the spring-cage chamber to expose the top of the spring-cage receiver 8 to the top of the upper support platform 6 of the spring-cage chamber, install the spring-cage adjusting screw 1 to the top of the spring-cage receiver 8 (the thread should be tightened), install the spring-cage adjusting nut 5 to the spring-cage adjusting screw 1, and push it to the top of the upper support platform 6 of the spring-cage chamber, and then the spring-cage mechanism is installed;

[0029] After the drill pipe reducer 4 is passed through the spring-cage adjusting screw 1 and connected to the upper end of the spring-cage cavity 7, the reducer 2 is passed through the reaming gasket 3 and the spring-cage adjusting screw 1 and connected to the upper end of the drill pipe reducer 4, the reducer assembly is installed, and the inner tube assembly is installed as a whole;

[0030] The next step is to install the core clamping mechanism. After fixing the core clamping mechanism 24 to the inner step 25 of the drill bit, the outer tube 26 is connected, the outer tube 26 is inserted into the inner tube assembly, and the upper end of the outer tube 26 is connected to the outer diameter male buckle of the drill pipe reducer 4 of the drill tool. The installation of the local reverse circulation single-action double-tube drilling tool is completed.

[0031] During normal drilling, the inner tube 22 in the core clamping protection mechanism 23 needs to be about 1.5-2 cm away from the upper end of the clamping spring (the spacing is adjusted by the locking nut 18 and the spring-adjusting nut 5); when lifting the drill, a slight piercing is performed, that is, the drill tool is raised by 10 cm and then quickly lowered to the bottom of the hole, so that the inner tube assembly pushes the telescopic clamping spring 27 of the core clamping protection mechanism along the guide groove 24.1 to the lower end of the clamping spring seat 24, and the clamping spring sheet returns to its original curvature, further reducing the inner diameter of the bottom of the drill bit, which plays a role in clamping and preventing the core from falling off.

[0032] The use process of the utility model is as follows:

[0033] First, the ejection single-action mechanism, the local reverse circulation mechanism and the inner tube 22 are sequentially connected to form an inner tube assembly;

[0034] Secondly, after the core clamping protection mechanism is installed into the upper end of the inner step of the drill bit, the outer tube 26 and the drill bit are connected to form an outer tube assembly;

[0035] Then the inner tube assembly and the outer tube assembly are connected to the drill pipe reducer to form a complete set of drilling tools. The installation order of the reducer assembly is as follows: the expansion gasket 3 is put on the outer ring of the drill pipe reducer 4 and then connected to the reducer 2;

[0036] Finally, the assembled drilling tool is connected to the active drill pipe and lifted vertically. The contact between the inner tube 22 and the core clamping protection mechanism 23 is observed from below the drill bit. Before drilling, the lower end of the inner tube 22 is in the core clamping protection mechanism 23, and the distance from the telescopic clamp spring is 1.5-2cm. Otherwise, the inner tube assembly gap is corrected by adjusting the spring clamp adjusting screw 1 (the spacing is adjusted by the locking nut 18 and the spring clamp adjusting nut 5). After correction, it can be used for drilling;

[0037] Before lifting the drill, perform slight pier drilling, that is, pull the drill bit up 10 cm and then quickly lower it to the bottom of the hole, so that the inner tube assembly pushes the telescopic retaining spring of the core clamping protection mechanism 23 to the lower end of the retaining spring seat 24 to restore it to the original curvature. The designed telescopic retaining spring has better strength and curvature than ordinary grabbing springs, which can meet the purpose of retaining spring clamping the core.

[0038] During normal drilling, the core enters the inner tube 22 from bottom to top, and the gas in the inner tube 22 is discharged to the middle channel 15.7 of the local reverse circulation inner tube connection part 15.6 along the hollow hole of the filter cup body 21.2, the filter cup cover 21.1, and the through screw 20. As the internal pressure of the inner tube 22 increases, the steel ball 15.8 is pushed to the top of the channel 15.7 by the air pressure, and the gas is discharged to the outside of the inner tube assembly along the horizontal exhaust hole at the upper end of the local reverse circulation inner tube connection part 15.6, so as to avoid the core being not drilled due to air blockage. The problem of the core entering the inner tube 22; when the drill is lifted, the core stops entering the inner tube 22. At this time, the steel ball 15.8 is affected by gravity and falls to the top of the through-hole 15.7 along the middle screw 20. When the drill is lifted, the steel ball 15.8 blocks the upper end of the exhaust hole of the through-hole 20, and the air cannot be sucked into the inner tube 22. There is a negative pressure area at the top of the inner tube 22, which avoids the problem of the core falling. At the same time, a filter is set in the filter locking mechanism 21. During the drilling process, the problem of blockage of the channel 15.7 caused by sand and gravel entering the exhaust hole is avoided.

[0039] The technical contents not specifically described in the present utility model and the above embodiments are the same as the prior art.

[0040] The above are only specific implementation methods disclosed in the present utility model, but the protection scope of the present utility model is not limited thereto. The protection scope of the present utility model shall be based on the protection scope of the claims.

Claims

1. A core-stuck protection mechanism, characterized in that: The core clamping protection mechanism includes a retaining spring seat and a telescopic retaining spring. The retaining spring seat is cylindrical, and a guide groove passes vertically downward through the lower part of the side wall. There are multiple guide grooves, which are arranged around the retaining spring seat. A steel ring is horizontally arranged around the inner side of the lower end of the guide groove. The telescopic retaining spring includes a steel ring and a retaining spring sheet. The retaining spring sheet is arranged on the steel ring. There are multiple retaining spring sheets corresponding to the guide groove, which are arranged around the steel ring. The steel ring is arranged in the retaining spring seat and can slide up and down along the retaining spring seat. The retaining spring sheet can slide up and down along the guide groove, and the lower end extends to the outside of the steel ring.

2. The core clamping protection mechanism according to claim 1, characterized in that: A plurality of slots are arranged around the outer wall of the steel ring, and the arrangement position is consistent with the guide slot position. A through hole is arranged in the middle of the slot. The upper end of the spring sheet is embedded in the steel ring slot and connected to the steel ring through the steel ring rivet and the through hole.

3. The core clamping protection mechanism according to claim 2 is characterized in that: The clamping spring piece is a spring piece with an arc.

4. The core clamping protection mechanism according to any one of claims 1 to 3, characterized in that: A plurality of guide grooves are evenly distributed on the retaining spring seat, and a plurality of retaining spring sheets are evenly distributed on the steel ring accordingly.

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