Two-stage drill bit for gas extraction drilling

Abstract

The utility model relates to the field of gas extraction, and discloses a two-stage drill bit for gas extraction drilling, which comprises a first-stage drill bit and a second-stage drill bit, the end face of the head part of the second-stage drill bit is provided with an insertion port, the tail part of the first-stage drill bit is provided with an insertion rod inserted with the insertion port, and the insertion port is in non-rotating insertion connection with the insertion rod; a plurality of elastic plug pins are further arranged on the outer wall of the second-stage drill bit, the sides, deviating from the first-stage drill bit, of the bottoms of pin rods of the elastic plug pins are first inclined planes, plugs are arranged at the bottoms of the first inclined planes, and first annular grooves matched with the plugs are formed in the plug rods; the inner cavity of the second-stage drill bit is further provided with an extrusion sleeve in threaded connection with the inserting rod and used for acting on the first inclined face to enable the inserting head to be separated from the first annular groove, and the end, away from the inserting rod, of the extrusion sleeve is provided with internal threads in threaded connection with an extraction pipe. Compared with the prior art, the device is unreasonable in structural design, and has the advantages of simplicity in operation and convenience in use.

Description

Technical Field

[0001] The utility model relates to the field of gas drainage, in particular to a two-stage drill bit for gas drainage boreholes. Background Technique

[0002] During the mining process of high-gas coal mines, it is necessary to drain gas. In the gas drainage construction process, it is necessary to first use a drill pipe to drill a drainage hole, and then withdraw the drill pipe and insert a drainage pipe into the drainage hole. In the actual operation process, for soft coal seams, when the drill pipe is withdrawn, the soft coal seam will collapse, making it impossible for the drainage pipe to reach the bottom of the gas drainage hole. Therefore, in the prior art, a coal mine gas drainage hole drill bit is provided to solve the above problems.

[0003] For example, a Chinese patent application with an application date of June 14, 2019 and an application number of CN201920897851.9 discloses a drill bit for coal mine gas drainage. The drill bit adopts a composite structure of an outer rod body and an inner rod body. After the drilling is completed, first insert the gas drainage pipe along the inner hole of the drill pipe and combine it with the inner rod body, and then withdraw the drill pipe and the outer rod body, which can solve the problems of soft coal seam drilling collapse and the inability of the gas drainage pipe to penetrate deeply. The existing drill bit has the following defects:

[0004] 1. The outer rod body and the inner rod body are connected by a threaded structure, which is not only troublesome to install, but also difficult to separate;

[0005] 2. In order to prevent the inner rod body from rotating relative to the outer rod body during drilling, resulting in the loosening of the inner rod body, a check structure is designed. The check sleeve is slidably connected to the necking section of the inner rod body, and the check can only be achieved by the torsion of the spring, and the check effect is not good.

[0006] Based on this, the present application provides a two-stage drill bit for gas drainage boreholes with a more reasonable structure design, simple operation and convenient use to solve the above problems. Utility Model Content

[0007] The utility model aims to solve the technical problems existing in the prior art. For this purpose, the utility model provides a two-stage drill bit for gas drainage boreholes with a more reasonable structure design, simple operation and convenient use.

[0008] The technical solution adopted by the utility model to solve its technical problems is:

[0009] Provided is a two-stage drill bit for gas drainage boreholes, including a first-stage drill bit and a second-stage drill bit; a socket is provided on the head end face of the second-stage drill bit, and a plug rod that is plugged into the socket is provided at the tail of the first-stage drill bit. The socket and the plug rod are non-rotatably plugged; a plurality of elastic pins are further provided on the outer wall of the second-stage drill bit. The bottom of the pin rod of the elastic pin is provided with a first inclined surface on the side away from the first-stage drill bit, and a plug is provided at the bottom of the first inclined surface. A first annular groove that matches the plug is provided on the plug rod; an extrusion sleeve that is screwed to the plug rod is further provided in the inner cavity of the second-stage drill bit for acting on the first inclined surface to disengage the plug from the first annular groove. An internal thread that is screwed to the gas drainage pipe is provided at the end of the extrusion sleeve away from the plug rod.

[0010] In some alternative embodiments, the socket is a stepped opening, including a through hole communicating with the inner cavity of the second-stage drill bit and a polygonal counterbore provided at the orifice of the through hole; the outer diameter of the plug rod matches the through hole, and a polygonal shoulder that matches the polygonal counterbore is further provided thereon.

[0011] In some alternative embodiments, a second annular groove is further provided in the polygonal counterbore, and a spring is fixedly installed at the bottom of the second annular groove.

[0012] In some alternative embodiments, a second inclined surface is provided at the end of the plug rod, and the lowest position of the second inclined surface is lower than the plug.

[0013] In some alternative embodiments, the height of the plug is less than the distance between the inner wall of the extrusion sleeve and the outer wall of the plug rod.

[0014] In some alternative embodiments, the extrusion sleeve includes an external thread pipe and a sleeve provided outside the external thread pipe. One end of the external thread pipe is threadedly connected to the inner hole of the plug rod, and the other end is threadedly connected to the external thread of the gas drainage pipe. The end of the sleeve away from the plug rod is an integral structure with the external thread pipe.

[0015] In some alternative embodiments, the internal thread of the gas drainage pipe and the internal thread of the inner hole of the plug rod have the same helix direction.

[0016] In some alternative embodiments, a plurality of water through holes communicating with its inner cavity are provided on the first-stage drill bit.

[0017] In some alternative embodiments, the elastic pins are screwed to the second-stage drill bit.

[0018] Compared with the prior art, the beneficial effects of the present utility model are:

[0019] 1. The first-stage drill bit and the second-stage drill bit of the utility model adopt a non-rotating plug-in structure, and the elastic pin and the first annular groove are used for limiting to realize the fixed connection between the first-stage drill bit and the second-stage drill bit. It has the advantages of simple assembly, and can better prevent relative rotation between the first-stage drill bit and the second-stage drill bit;

[0020] 2. An extrusion sleeve is also designed. The extrusion sleeve is pre-installed on the gas extraction pipe. When it is necessary to push out the second-stage drill bit, the gas extraction pipe is inserted from the drill pipe, so that the extrusion sleeve is screwed with the first-stage drill bit. As the extrusion sleeve is screwed in, the first inclined surface of the elastic pin is extruded by the extrusion sleeve, so that the plug of the elastic pin is disengaged from the first annular groove. At this time, the second-stage drill bit can be pulled out. This structural design makes the separation operation of the first-stage drill bit and the second-stage drill bit simpler. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained according to these drawings, where:

[0022] Figure 1 is a cross-sectional view of the two-stage drill bit for gas extraction drilling provided by the present utility model;

[0023] Figure 2 is a separation state diagram of the two-stage drill bit for gas extraction drilling provided by the present utility model;

[0024] Figure 3 is a right view of the second-stage drill bit provided by the present utility model;

[0025] Figure 4 is a left view of the first-stage drill bit provided by the present utility model;

[0026] Figure 5 is Figure 1 a partial enlarged view of part A provided;

[0027] Figure 6 is Figure 2 a partial enlarged view of part B provided.

[0028] In the drawings, the list of components represented by each reference numeral is as follows:

[0029] 1—First-stage drill bit, 1.1—Insert rod, 1.1.1—Polygonal shoulder, 1.1.2—First annular groove, 1.2—Water through-hole, 1.1.3—Second inclined surface, 2—Second-stage drill bit, 2.1—Insert interface, 2.1.1—Through-hole, 2.1.2—Polygonal counterbore, 2.1.3—Second annular groove, 3—Elastic pin, 3.1—First inclined surface, 3.2—Plug, 4—Extrusion sleeve, 4.1—External threaded pipe, 4.2—Sleeve, 5—Extraction pipe, 6—Spring. Detailed implementation mode

[0030] It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0031] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present invention.

[0032] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present invention and simplifying the 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;

[0033] In addition, the descriptions of the terms "first", "second", etc. in the present invention are only for descriptive purposes, and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. The terms "installation", "connection", and "connection" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected, or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0034] In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement it. When the combination of the technical solutions appears to be contradictory or unable to be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present invention.

[0035] Embodiment 1

[0036] As attached Figure 1 As shown, this embodiment provides a two-stage drill bit for gas extraction drilling, including a first-stage drill bit 1 and a second-stage drill bit 2. The head end face of the second-stage drill bit 2 is provided with an insertion port 2.1, and the tail of the first-stage drill bit 1 is provided with an insertion rod 1.1 plugged into the insertion port 2.1. The insertion port 2.1 and the insertion rod 1.1 are non-rotatably plugged. The non-rotatably plugging method of this embodiment is preferably: as shown in the attached Figure 1 , Attachment Figure 3 And attached Figure 4 As shown, the insertion port 2.1 is configured as a stepped port, including a through hole 2.1.1 communicating with the inner cavity of the second-stage drill bit 2 and a polygonal countersunk hole 2.1.2 provided at the through hole opening; the outer diameter of the insertion rod 1.1 matches the through hole 2.1.1, and a polygonal shoulder 1.1.1 matching the polygonal countersunk hole 2.1.2 is also provided thereon. The polygonal countersunk hole in this embodiment can be a regular hexagonal hole, and the corresponding polygonal shoulder can be a regular hexagonal shoulder. In other embodiments, a regular quadrilateral, a regular pentagon, etc. can also be used.

[0037] In order to achieve the fixation of the first-stage drill bit and the second-stage drill bit after plugging, as shown in the attached Figure 1 and attached Figure 5 As shown, in this embodiment, a plurality of elastic plugs 3 are further provided on the outer wall of the second-stage drill bit 2, and the side of the bottom of the pin rod of the elastic plug 3 facing away from the first-stage drill bit 1 is set as a first inclined surface 3.1, and a plug 3.2 is provided at the bottom of the first inclined surface 3.1, and a first annular groove 1.1.2 matching the plug 3.2 is provided on the plug rod 1.1. Preferably, a second inclined surface 1.1.3 is provided at the end of the plug rod 1.1, and the lowest position of the second inclined surface 1.1.3 is lower than the plug 3.2. This design ensures that the plug will not affect the entry of the plug rod, ensuring that the plug rod can smoothly enter the plug interface.

[0038] The two-stage drill bit designed in this embodiment allows the first-stage drill bit and the second-stage drill bit to be quickly assembled. During the specific operation, the first-stage drill bit is inserted into the plug interface of the second-stage drill bit. After being inserted to a certain depth, it is rotated a certain distance to align the polygonal shoulder with the polygonal countersunk hole and then pushed in. After being pushed in, due to the limiting effect of multiple elastic pins, the first-stage drill bit and the second-stage drill bit will not fall out.

[0039] In order to solve the problem that the first-stage drill bit and the second-stage drill bit need to be separated after drilling is completed, as shown in the attached Figure 1 and attached Figure 2As shown, an extrusion sleeve 4 screwed to the insertion rod 1.1 is further provided in the inner cavity of the second-stage drill bit 2, which is used to act on the first inclined surface 3.1 to disengage the plug 3.2 from the first annular groove 1.1.2. One end of the extrusion sleeve 4 away from the insertion rod 1.1 is provided with an internal thread screwed to the extraction pipe 5. Preferably, the extrusion sleeve 4 includes an external thread pipe 4.1 and a sleeve 4.2 arranged outside the external thread pipe. One end of the external thread pipe 4.1 is threadedly connected to the inner hole of the insertion rod 1.1, and the other end is threadedly connected to the external thread of the extraction pipe 5. One end of the sleeve 4.2 away from the insertion rod 1.1 is integrally structured with the external thread pipe 4.1. Preferably, the internal thread of the extraction pipe 5 and the internal hole thread of the insertion rod 1.1 have the same helix direction. The designed extrusion sleeve in this embodiment is pre-installed on the extraction pipe. When it is necessary to push out the second-stage drill bit, as shown in the appendix Figure 2 As shown, the extraction pipe is inserted from the drill pipe so that the extrusion sleeve is screwed to the first-stage drill bit. As the extrusion sleeve is screwed in, the first inclined surface of the elastic insertion pin is extruded by the extrusion sleeve, causing the plug of the elastic insertion pin to disengage from the first annular groove, as shown in the appendix Figure 6 As shown, at this time, the second-stage drill bit can be withdrawn, and this structural design makes the separation operation of the first-stage drill bit and the second-stage drill bit simpler.

[0040] Preferably, as shown in the appendix Figure 5 and the appendix Figure 6 As shown, the height of the plug 3.2 is less than the distance between the inner wall of the extrusion sleeve 5 and the outer wall of the insertion rod 1.1, specifically less than the distance between the inner wall of the sleeve 4.2 and the outer wall of the insertion rod 1.1. This design can ensure that the plug disengages from the first annular groove under the action of the extrusion sleeve.

[0041] Preferably, a plurality of water through holes 1.2 communicating with its inner cavity are provided on the first-stage drill bit 1 for water passing during drilling.

[0042] Preferably, the elastic insertion pin 3 is screwed to the second-stage drill bit 2, which is a detachable installation method, facilitating the maintenance of the drill bit. The structure of the elastic insertion pin mainly includes a cylinder body, an insertion pin, a spring, and a plug head. This structure is prior art and will not be elaborated here.

[0043] Embodiment 2

[0044] Repeat Embodiment 1. As shown in the appendix Figure 1 and the appendix Figure 2 As shown, in this embodiment, a second annular groove 2.1.3 is further provided in the polygonal counterbore 2.1.2, and a spring 6 is fixedly installed at the bottom of the second annular groove 2.1.3. This design makes the spring in a compressed state when the first-stage drill bit and the second-stage drill bit are assembled; when the drilling is completed, under the action of the extrusion sleeve, the elastic insertion pin disengages from the first annular groove. At this time, under the action of the spring restoring force, the second-stage drill bit can be quickly separated from the first-stage drill bit.

[0045] The above are only embodiments of the present utility model, and thus do not limit the patent scope of the present utility model. Any equivalent structure or equivalent process transformation made by using the content of the specification of the present utility model, or directly or indirectly applied in other related technical fields, shall similarly be included within the patent protection scope of the present utility model.

Claims

1. A two-stage drill bit for gas extraction drilling, comprising a first-stage drill bit and a second-stage drill bit; characterized in that: The head end face of the second-stage drill bit is provided with an insertion port, and the tail of the first-stage drill bit is provided with an insertion rod plugged into the insertion port, and the insertion port and the insertion rod are non-rotatably plugged; The outer wall of the second-stage drill bit is also provided with a plurality of elastic plugs, the bottom of the pin rod of the elastic plug is provided with a first inclined surface on the side away from the first-stage drill bit, the bottom of the first inclined surface is provided with a plug, and the plug rod is provided with a first annular groove matching the plug; The inner cavity of the second-stage drill bit is also provided with an extrusion sleeve threadedly connected to the insertion rod, which is used to act on the first inclined surface to make the plug disengage from the first annular groove. The end of the extrusion sleeve away from the insertion rod is provided with an internal thread threadedly connected to the extraction pipe.

2. The two-stage drill bit for gas extraction drilling according to claim 1, characterized in that: The insertion port is configured as a stepped port, including a through hole connected to the inner cavity of the second-stage drill bit and a polygonal countersunk hole provided at the opening of the through hole; the outer diameter of the insertion rod matches the through hole, and a polygonal shoulder matching the polygonal countersunk hole is also provided thereon.

3. The two-stage drill bit for gas extraction drilling according to claim 2, characterized in that: A second annular groove is also provided in the polygonal countersunk hole, and a spring is fixedly installed at the bottom of the second annular groove.

4. The two-stage drill bit for gas extraction drilling according to claim 1, characterized in that: A second inclined surface is disposed at the end of the insertion rod, and the lowest position of the second inclined surface is lower than the plug.

5. The two-stage drill bit for gas extraction drilling according to claim 1, characterized in that: The height of the plug is smaller than the distance between the inner wall of the extrusion sleeve and the outer wall of the insertion rod.

6. The two-stage drill bit for gas extraction drilling according to claim 1, characterized in that: The extrusion sleeve includes an externally threaded tube and a sleeve arranged outside the externally threaded tube. One end of the externally threaded tube is threadedly connected to the inner hole of the insertion rod, and the other end is threadedly connected to the external thread of the extraction tube. The end of the sleeve away from the insertion rod is an integrated structure with the externally threaded tube.

7. The two-stage drill bit for gas extraction drilling according to claim 6, characterized in that: The internal thread of the extraction tube and the internal thread of the insertion rod have the same rotation direction.

8. The two-stage drill bit for gas extraction drilling according to claim 1, characterized in that: The first-stage drill bit is provided with a plurality of water holes connected with its inner cavity.

9. The two-stage drill bit for gas extraction drilling according to claim 1, characterized in that: The elastic plug is screwed onto the second-stage drill bit.

Images