Contracted tube of coal mine underground gas drainage sieve tube

Abstract

The utility model relates to the technical field of screen pipes, in particular to a coal mine underground gas drainage screen pipe contracted pipe which comprises a screen pipe body, one end of the screen pipe body is fixedly connected with a contracted pipe, external threads are arranged on the outer wall of the contracted pipe, and internal threads matched with the external threads are arranged on the inner wall of the end, away from the contracted pipe, of the screen pipe body. Compared with the prior art, according to the scheme, the contracted pipe is arranged, the external threads are formed in the contracted pipe, the pipe wall of the joint of the screen pipe body is thick, meanwhile, the internal threads formed in the end, away from the contracted pipe, of the screen pipe body are matched with the external threads on the outer wall of the contracted pipe, and the wall thickness of the joint is increased similarly; the stability and rigidity of the screen pipe body after connection are further enhanced, and the technical problem that due to the fact that the wall thickness of an existing machined screen pipe body is small, the threaded connection position is fractured and deformed is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of screen pipes, in particular to a shrinkable screen pipe for gas extraction in underground coal mines. Background Art

[0002] The screen pipe used for gas extraction in coal mines is connected by the external thread of one screen pipe and the internal thread of another screen pipe in sequence, and the connection length reaches a kilometer. The screen pipe body currently used is made of 6mm wall thickness seamless steel pipe. Because the inner and outer diameters of each connecting screen pipe are processed by seamless pipes of uniform size, the common method is used to process the inner and outer threads to match the size of the inner threads. When processing the outer threads, the outer pipe wall must be turned to remove the excess steel; similarly, when processing the inner threads, the inner wall steel of the pipe must also be turned to remove the steel, so as to ensure the connection of the inner and outer threads.

[0003] According to the screen pipe processed by the prior art, after the inner (outer) thread height size is removed, the remaining pipe wall size is thin and the strength is low, which easily causes the outer or inner thread of the screen pipe end connection to be torsion fracture at the root of the thread connection and tearing of the thread wall when the inner and outer threads of two adjacent screen pipes are connected to convey the screen pipe to the coal wall drilling hole due to low connection strength, which cannot meet the needs of gas extraction in kilometer-long directional drilling. Furthermore, because the wall of the threaded pipe is thin after processing, the inner and outer thread walls are easily deformed and damaged due to collision during loading and unloading and transportation, and cannot be used. Utility Model Content

[0004] The utility model aims to provide a gas extraction screen pipe shrinkage pipe for underground coal mines, which is mainly used to solve the technical problems in the prior art that the wall thickness of the processed screen pipe is relatively thin, and thread connection breakage and deformation are very likely to occur during actual use.

[0005] In order to solve the above technical problems, the utility model provides the following technical solutions:

[0006] A gas extraction screen tube shrinkage tube for underground coal mines comprises a screen tube body, one end of which is fixedly connected to a shrinkage tube, an outer wall of which is provided with an outer thread, and an inner wall of which is away from the shrinkage tube and is provided with an inner thread matching the outer thread.

[0007] The working principle and beneficial effects of the utility model:

[0008] 1. Working principle: Before the external thread end of the screen tube body is processed, the shrink tube at one end of the screen tube body is fixedly connected, and the external thread is opened on the outer wall of the shrink tube, which increases the wall thickness of the screen tube body at the connection. At the same time, the internal thread opened at the end of the screen tube body away from the shrink tube matches the external thread of the outer wall of the shrink tube, which increases the wall thickness at this point and further enhances the stability and rigidity of the screen tube body after connection.

[0009] 2. Beneficial effects:

[0010] This solution sets a reduced pipe, and an external thread is provided on the reduced pipe, so that the wall thickness of the pipe wall at the connection of the screen pipe body is increased. At the same time, an internal thread is provided at one end of the screen pipe body far from the reduced pipe, which matches the external thread on the outer wall of the reduced pipe. Similarly, the wall thickness at this place is increased, further enhancing the stability and rigidity of the screen pipe body after connection, and solving the technical problem that the wall thickness of the existing screen pipe body is relatively thin during processing, resulting in fracture and deformation at the threaded connection.

[0011] Preferably, the outer diameter of the reduced pipe is not greater than the outer diameter of the screen pipe body.

[0012] Preferably, the difference in outer diameter between the screen pipe body and the reduced pipe is 6 mm.

[0013] Preferably, an arc chamfer is provided at the junction of the reduced pipe and the screen pipe body.

[0014] Preferably, the wall thickness of the inner wall of the screen pipe body near the location where the internal thread is provided is set to match the outer diameter of the reduced pipe. Description of the Drawings

[0015] Figure 1 It is a three-dimensional structure diagram of a reduced pipe for a gas drainage screen pipe in a coal mine underground of the utility model patent.

[0016] Figure 2 It is a reduced pipe structure diagram of a reduced pipe for a gas drainage screen pipe in a coal mine underground of the utility model patent.

[0017] The reference numerals in the drawings of the specification include: 1, screen pipe body; 2, reduced pipe; 3, external thread; 4, internal thread; 5, arc chamfer. Detailed Embodiment

[0018] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all of the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present utility model.

[0019] Such as Figure 1 - Figure 2As shown in the figure, a gas drainage screen pipe necking for underground coal mines includes a screen pipe body 1. One end of the screen pipe body 1 is integrally formed and connected with a necking pipe 2, or it can be processed subsequently (the processing method of the necking pipe 2 can be processed by a necking machine, and this processing method belongs to a common processing method, so the processing principle is not described in detail in this application document). An arc chamfer 5 is provided at the junction of the necking pipe 2 and the screen pipe body 1. The outer diameter of the necking pipe 2 is not greater than the outer diameter of the screen pipe body 1, and the outer diameter difference between the screen pipe body 1 and the necking pipe 2 is 6 mm. An external thread 3 is provided on the outer wall of the necking pipe 2, and an internal thread 4 matching the external thread 3 is provided on the inner wall of the end of the screen pipe body 1 far from the necking pipe 2. The wall thickness of the inner wall of the screen pipe body 1 near the location where the internal thread 4 is provided is set to match the outer diameter of the necking pipe 2.

[0020] As can be seen from the above, the specific implementation manner of the present utility model is as follows:

[0021] Before processing the external thread end of the screen pipe body 1, the necking pipe 2 fixed to one end of the screen pipe body 1. Since the outer diameter difference between the necking pipe 2 and the screen pipe body 1 is 6 mm, it can be known that the outer diameter of the necking pipe 2 is smaller than the outer diameter of the screen pipe body 1. At the same time, the external thread 3 is provided on the outer wall of the necking pipe 2, and the wall thickness of the inner wall of the screen pipe body 1 near the location where the internal thread 4 is provided is set to match the outer diameter of the necking pipe 2. Therefore, the internal thread 4 provided at the end of the screen pipe body 1 far from the necking pipe 2 matches the external thread 3 on the outer wall of the necking pipe 2. Similarly, the wall thickness at this location is increased, further increasing the wall thickness of the pipe wall at the connection of both ends of the screen pipe body 1, enhancing the stability and rigidity of the screen pipe body 1 after connection, and reducing the phenomenon of fracture and deformation due to the relatively thin wall thickness at the threaded connection of the screen pipe body 1.

[0022] The above are only the embodiments of the present utility model, and common knowledge such as the specific structures and characteristics known in the solutions is not described in detail here. It should be noted that for those skilled in the art, without departing from the structure of the present utility model, several deformations and improvements can be made, and these should also be regarded as the protection scope of the present utility model, and these will not affect the implementation effect of the present utility model and the practicality of the patent. The protection scope required by this application should be subject to the content of its claims, and the specific implementation manners described in the specification can be used to explain the content of the claims.

Claims

1. A gas extraction screen pipe shrinkage pipe for underground coal mines, comprising a screen pipe body (1), characterized in that: A shrink tube (2) is fixedly connected to one end of the sieve tube body (1), an outer wall of the shrink tube (2) is provided with an external thread (3), and an inner wall of an end of the sieve tube body (1) away from the shrink tube (2) is provided with an internal thread (4) matching the external thread (3).

2. The shrink pipe for gas drainage screen pipe in underground coal mine according to claim 1, characterized in that: The outer diameter of the shrink tube (2) is not greater than the outer diameter of the screen tube body (1).

3. The shrink pipe for gas drainage screen pipe in underground coal mine according to claim 1, characterized in that: The difference in outer diameter between the screen tube body (1) and the shrink tube (2) is 6 mm.

4. The shrink pipe for gas drainage screen pipe in underground coal mine according to claim 1, characterized in that: A circular chamfer (5) is provided at the junction of the shrink tube (2) and the screen tube body (1).

5. The shrink pipe for gas drainage screen pipe in underground coal mine according to claim 1, characterized in that: The thickness of the inner wall of the screen tube body (1) near the inner thread (4) is matched with the outer diameter of the shrink tube (2).

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