CN216517892U

CN216517892U - Anti-backflow airtight coring bit

Info

Publication number: CN216517892U
Application number: CN202123109806.9U
Authority: CN
Inventors: 丁华忠; 程合玉; 刘德贵; 龙威成; 张朋; 周伟东; 万玉柱; 李铁; 田宏杰; 范运林
Original assignee: Huainan Mining Group Co Ltd
Current assignee: Huainan Mining Group Co Ltd
Priority date: 2021-12-10
Filing date: 2021-12-10
Publication date: 2022-05-13
Anticipated expiration: 2031-12-10

Abstract

The utility model discloses an anti-backflow airtight core bit which is of a hollow tubular structure and comprises an inner bit, an outer bit and an anti-backflow device, wherein the inner bit and the outer bit are fixedly connected and are both of a hollow structure, the outer bit is uniformly provided with a plurality of cutting blades along the circumferential direction of the top of a bit body of the outer bit, a chip removal channel and a Y-shaped through pipeline are arranged between every two adjacent cutting blades, the anti-backflow device is arranged in the through pipeline and comprises steel balls arranged at the intersection of the through pipeline in a sliding mode, and the diameter of each steel ball is larger than the diameter of a main pipeline of the through pipeline. According to the utility model, the main pipeline of the through pipeline can be blocked through the arrangement of the steel balls, the main pipeline can be conducted under the action of pressure when the coring device is normally used, and the main pipeline can be blocked when the coring device flows back, so that the coal taking device and the inner stepped annular channel of the drill bit are prevented from being blocked by backflow of coal slag in the process of pressing air to take coal, the normal state of the coring device is effectively ensured, and the closed coring of a broken soft coal bed is better realized.

Description

Anti-backflow airtight coring bit

Technical Field

The utility model relates to the technical field of accurate determination of the content of underground coal mine airtight coring gas, in particular to an anti-backflow airtight coring bit.

Background

At present, mine gas is a major potential safety hazard in coal mining, and mine gas treatment is an important technical means for ensuring safe and efficient mining of coal mines. Before mine gas treatment, gas content determination is carried out on a coal seam to be mined, which is a necessary prospect work, and the gas content determination can provide theoretical support for subsequent treatment. The conventional coring method is adopted for measuring the gas content, the measured gas content value is far smaller than the actual content value, the gas content estimation is inaccurate, and hidden dangers are buried for gas exploration and development and safe and efficient coal mine exploitation.

Patent document that current patent publication number is CN112112575A discloses an airtight core bit of getting in garrulous soft coal seam suitable for ground drilling, including outer drill bit, interior drill bit and drill bit body, the drill bit body has by preceding three-step hole that increases gradually to back aperture, outer drill bit sets firmly in the outer rampart of drill bit body front end, and outer drill bit is provided with a plurality of cutting wings, forms the guiding gutter between two adjacent cutting wings, interior drill bit demountable installation is in the path hole section of three shoulder holes, and the water hole that communicates with the guiding gutter has been seted up to the one-level step face between the major diameter hole section of three shoulder holes and the great path hole section, and the annular has been seted up to the great path hole section of three shoulder holes, the annular is used for installing the sealing washer. Through having the airtight corer that can open, the original state nature of the sample coal body has been guaranteed to the at utmost, has improved the measurement accuracy of coal seam gas content greatly, has solved the technical problem of coal sample authenticity, nevertheless at the pressure wind coal taking in-process, because downthehole gas pressure is great, the cinder often can enter into the coal taking device along with the water route suck-back, blocks up and gets coal device and drill bit interior ladder annular space passageway, and then makes the coal taking device lose efficacy, influences the coal taking effect.

SUMMERY OF THE UTILITY MODEL

The utility model aims to solve the technical problem of how to prevent coal slag from flowing back to block a coal taking device and a stepped annular channel in a drill bit in the process of pressing air to take coal.

The utility model solves the technical problems through the following technical means: the utility model provides an airtight core bit of getting of anti-return, airtight core bit of getting is the hollow tubular structure, including interior drill bit, outer drill bit, anti-return device, interior drill bit just is hollow structure with outer drill bit fixed connection, outer drill bit evenly is equipped with a plurality of cutting wings along its drill body top circumference, and is adjacent be equipped with chip removal passageway and Y type link up the pipeline between the cutting wing, it is equipped with anti-return device in the pipeline to link up, anti-return device locates the steel ball that link up the pipeline cross section including sliding, the steel ball diameter is greater than and link up the pipeline main line diameter.

Can block up through the pipeline main line through setting up of steel ball, during the normality was used, under the pressure effect, can make the main line switch on, during the backward flow, can block up the main line, prevented to get coal in-process cinder backward flow at the forced air and blockked up and got coal device and drill bit inner ladder annular space passageway, effectively ensured coring device's normal condition, the airtight coring in better realization garrulous soft coal seam.

As an optimized technical scheme, the backflow prevention device further comprises an expansion spring, a plug and a blocking net, wherein the expansion spring, the plug and the blocking net are all located in a branch pipeline penetrating through the pipeline, the steel ball can axially move in the blocking net along the blocking net, the plug is detachably fixed at an inlet of the branch pipeline, and the plug is elastically connected with the steel ball through the expansion spring.

As a preferred technical scheme, the outer drill bit comprises a drill bit body, an annular groove and a central through hole, the annular groove matched with the drill bit body is formed in the joint of the drill bit body and the inner drill bit, the central through hole matched with the inner part of the coal taking device is formed in the center of the drill bit body, and a chip removal channel is formed between every two adjacent cutting blades.

According to the preferable technical scheme, the top of the inner drill bit is provided with a plurality of tooth grooves, alloy cutting teeth are fixedly connected in the tooth grooves, the center of the inner drill bit is provided with an inner through hole matched with the inner part of the coal taking device, and the axis of the inner drill bit is coaxial with the center through hole.

According to the preferable technical scheme, the cutting blades comprise PDC cutting teeth and gauge protection teeth, the PDC cutting teeth are fixedly connected with the gauge protection teeth, the front end face of the inner drill bit protrudes out of the front end face of the drill bit along the axial direction of the inner drill bit, the PDC cutting teeth and the gauge protection teeth are arranged on the front end face of the drill bit, and the sampling rate and the measuring success rate of a coal bed can be improved through the design of the stepped structures of the inner drill bit and the outer drill bit.

As a preferable technical scheme, the included angle between the axis of the through pipeline and the axis of the core bit is 40-45 degrees.

As a preferred technical scheme, the inner drill bit and the outer drill bit are connected in a threaded mode.

As a preferred technical scheme, a plurality of through small holes are formed in the outer wall of the blocking net.

As a preferable technical scheme, the number of the tooth grooves is four.

As a preferred technical scheme, a through hole is formed in the plug.

The utility model has the advantages that:

(1) according to the utility model, the main pipeline of the through pipeline can be blocked through the arrangement of the steel balls, the main pipeline can be conducted under the action of pressure when the coring device is normally used, and the main pipeline can be blocked when the coring device flows back, so that the coal taking device and the inner stepped annular channel of the drill bit are prevented from being blocked by backflow of coal slag in the process of pressing air to take coal, the normal state of the coring device is effectively ensured, and the closed coring of a broken soft coal bed is better realized.

(2) According to the utility model, the design of the stepped structures of the inner drill bit and the outer drill bit can improve the sampling rate and the measuring success rate of the coal seam.

Drawings

FIG. 1 is a schematic view of the overall structure of a backflow prevention closed core bit according to an embodiment of the present invention;

FIG. 2 is a schematic cross-sectional view of a back-flow prevention encapsulated core drill bit according to an embodiment of the present invention;

FIG. 3 is a schematic view of an inner bit structure of a backflow prevention closed core bit according to an embodiment of the present invention;

FIG. 4 is a schematic view of an outer bit structure of a backflow prevention closed core bit according to an embodiment of the present invention;

FIG. 5 is a schematic view of a retaining screen of a backflow prevention closed core bit according to an embodiment of the present invention;

FIG. 6 is an enlarged partial schematic view of the FIG. 2 portion of a back-flow prevention encapsulated core drill bit according to an embodiment of the present invention;

reference numbers: 1. an inner drill bit; 101. a tooth socket; 102. an alloy cutting tooth; 103. an inner through hole; 2. An outer drill bit; 201. a bit body; 202. a pipeline is communicated; 203. PDC cutting teeth; 204. gauge protection teeth; 205. a chip removal channel; 206. an annular groove; 207. a central through hole; 3. a backflow prevention device; 301. Steel balls; 302. a tension spring; 303. a plug; 304. blocking the net; 30401. and (4) a small hole.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1, a backflow prevention airtight core bit, which is a hollow tubular structure, includes: the anti-backflow device comprises an inner drill bit 1, an outer drill bit 2 and an anti-backflow device 3, wherein the inner drill bit 1 and the outer drill bit 2 are fixedly connected in a mode of welding or screw thread fixing, the inner drill bit 1 and the outer drill bit 2 are both of a hollow structure, the tail of the outer drill bit 2 is provided with an annular step hole, the anti-backflow device 3 is arranged in the annular step hole in the outer drill bit 2, and the annular step hole forms a Y-shaped through pipeline 202 main pipeline;

the top of the inner drill bit 1 is provided with a plurality of tooth grooves 101 for placing alloy cutting teeth 102, it should be noted that in this embodiment, the number is preferably four, the alloy cutting teeth 102 are fixedly connected in the tooth grooves 101 in an insert welding manner, the center of the inner drill bit 1 is provided with an inner through hole 103 matched with the inner part of the coal sampler, and the inner diameter and the outer diameter of the inner drill bit 1 after insert welding are both larger than the diameter of the inner drill bit 1;

referring to fig. 2, 3 and 4, the outer drill bit 2 includes a bit body 201, a through pipe 202, cutting blades, a debris discharge channel 205, an annular groove 206, and a central through hole 207; an annular step-shaped groove is formed in the inner side of the bottom of a bit body 201 to form a main pipeline of a Y-shaped through pipeline 202, a central through hole 207 for a coal core to pass through is formed in the center of the bit body 201, the central through hole 207 is matched with an inner hole of a coal taking device, an annular groove 206 matched with the bit body is formed in the joint of the bit body 201 and an inner drill bit 1 (the top of the bit body 201), the annular groove 206 is concentric with the central through hole 207, the annular groove 206 is used for placing the inner drill bit 1, a plurality of cutting blades are uniformly arranged on the bit body 201 along the circumferential direction of the top of the bit body, the cutting blades comprise PDC cutting racks 203 and gauge protection teeth 204, cutting tooth grooves are formed in the cutting blades, PDC cutting racks 203 are arranged in the cutting racks, the cutting racks are four groups in number, a chip removal channel 205 and a Y-shaped through pipeline 202 are arranged between adjacent cutting blades, a chip removal channel 205 is formed between adjacent cutting blades, and the Y-shaped through pipeline 202 comprises a branch pipeline and a branch pipeline, the inlets of branch pipes of the Y-shaped through pipe 202 are arranged on the bit body 201 and positioned between adjacent cutting blades, and the included angle between the axis of the through pipe 202 and the axis of the core bit is 40-45 degrees, and can also be 40-45 degrees.

Referring to fig. 6, the backflow prevention device 3 includes a steel ball 301, a retractable spring 302, a plug 303, and a blocking net 304; the steel ball 301 is slidably disposed at the intersection of the through pipeline 202, the diameter of the steel ball 301 is larger than that of the main pipeline of the through pipeline 202 and is used for blocking the main pipeline, the extension spring 302, the plug 303 and the blocking net 304 are all located in the branch pipeline of the through pipeline 202, the steel ball 301 is elastically connected with the plug 303 through the extension spring 302, one end of the extension spring 302 is abutted against the steel ball 301, the other end of the extension spring 302 is abutted against the plug 303, the plug 303 is detachably fixed at the inlet of the branch pipeline, the plug 303 is connected with the inlet of the branch pipeline in a clamping manner, a through hole is formed in the plug 303 for facilitating ventilation and water communication, the diameter of the branch pipeline is larger than that of the blocking net 304, so as to facilitate installation of the backflow prevention device 3, referring to fig. 5, a plurality of through small holes 30401 are formed in the outer wall of the blocking net 304 for facilitating ventilation and water communication, a plurality of the through small holes 30401 are circumferentially distributed along the outer wall of the blocking net 304 in a crossed manner so as to ensure the strength of the blocking net 304, the blocking net 304 is slightly larger than the diameter of the steel ball 301 by 0.5-1mm, the steel ball 301 can move axially along the blocking net 304 in the blocking net 304, and the extension spring 302 is in a compressed state in a normal state, and the steel ball 301 is located at the intersection of the through pipeline 202.

The machining process of the anti-backflow airtight coring bit comprises the following steps: respectively processing an inner drill bit 1 and an outer drill bit 2, fixing PDC cutting teeth 203 (including gauge teeth 204) to the corresponding positions of a drill bit body 201 in a welding mode, fixing the inner drill bit 1 to the annular groove 206 of the outer drill bit 2, sequentially placing a cylindrical blocking net 304, a steel ball 301 and a telescopic spring 302 to the corresponding positions of the drill bit body 201, and fixing an installation plug 303.

The using method comprises the following steps: in a normal state, fluid is discharged from the bottom of the bit body 201 to inlets of the branch pipeline and the main pipeline through the through pipeline 202, and when backflow occurs, the steel ball 301 is clamped at the intersection of the through pipeline 202 under the elastic force action of the telescopic spring 302 to block the main pipeline, so that backflow is prevented.

The above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.

Claims

1. The utility model provides an airtight coring bit of preventing backward flow, airtight coring bit is the hollow tubular structure, a serial communication port, including interior drill bit (1), outer drill bit (2), anti-return means (3), interior drill bit (1) just is hollow structure with outer drill bit (2) fixed connection, outer drill bit (2) evenly are equipped with a plurality of cutting blades along its drill body top circumference, and are adjacent be equipped with chip removal passageway (205) and Y type between the cutting blade and link up pipeline (202), it is equipped with anti-return means (3) in pipeline (202) to link up, anti-return means (3) locate steel ball (301) of link up pipeline (202) cross section including sliding, steel ball (301) diameter is greater than link up pipeline (202) main pipeline diameter.

2. The anti-backflow airtight coring bit as claimed in claim 1, wherein the anti-backflow device (3) further comprises a telescopic spring (302), a plug (303) and a blocking net (304), the telescopic spring (302), the plug (303) and the blocking net (304) are all located in a branch pipeline of the through pipeline (202), the steel ball (301) can move axially along the blocking net (304) in the blocking net (304), the plug (303) is detachably fixed at an inlet of the branch pipeline, and the plug (303) is elastically connected with the steel ball (301) through the telescopic spring (302).

3. The anti-backflow airtight core-taking drill bit as claimed in claim 1, wherein the outer drill bit (2) comprises a drill bit body (201), an annular groove (206) and a central through hole (207), the annular groove (206) matched with the drill bit body (201) is formed at the joint of the drill bit body (201) and the inner drill bit (1), the central through hole (207) matched with the inner part of the coal taking device is formed in the center of the drill bit body, and a debris discharge channel (205) is formed between adjacent cutting blades.

4. The anti-backflow airtight core drill bit as claimed in claim 3, characterized in that a plurality of tooth grooves (101) are formed at the top of the inner drill bit (1), alloy cutting teeth (102) are fixedly connected in the tooth grooves (101), an inner through hole (103) matched with the inner part of the coal sampler is formed at the center of the inner drill bit (1), and the axis of the inner drill bit is coaxial with the central through hole (207).

5. The anti-backflow airtight core-taking drill bit as claimed in claim 3, characterized in that the cutting blades comprise PDC cutting teeth (203) and gauge teeth (204), the PDC cutting teeth (203) and the gauge teeth (204) are fixedly connected, the front end face of the inner drill bit (1) is protruded to the front end face of the drill bit body (201) along the axial direction, and the PDC cutting teeth (203) and the gauge teeth (204) are arranged on the front end face of the drill bit body (201).

6. The anti-backflow closed core drill bit as claimed in claim 1, characterized in that the angle between the axis of the through pipe (202) and the core drill bit axis is 40 ° to 45 °.

7. The anti-backflow closed core bit as claimed in claim 3, characterized in that the inner bit (1) and the outer bit (2) are screwed fixedly.

8. The anti-backflow airtight core drill bit as claimed in claim 2, wherein the blocking net (304) has a plurality of through holes (30401) on its outer wall.

9. The anti-backflow closed core drill bit as claimed in claim 4, wherein the number of gullets (101) is four.

10. The anti-backflow airtight core drill bit as claimed in claim 2, wherein the plug (303) is provided with a through hole.