阅读说明：本技术 一种反循环钻头 (Reverse circulation drill bit ) 是由 龚康强 孙超 于 2020-05-27 设计创作，主要内容包括：本发明提供了一种反循环钻头,它包括钻头主体,所述钻头主体的中心加工有中心气孔、孔腔及导流部；所述导流部设置在中心气孔和孔腔之间,所述空腔与收集管配合。通过采用上述结构的钻头有效的避免了岩样对收集管端面的冲击,提高了收集管的使用寿命；减少岩样采集时能量损失,提高了岩样的采集效率；保证了岩样的完整性。(The invention provides a reverse circulation drill bit, which comprises a drill bit main body, wherein a central air hole, a hole cavity and a flow guide part are processed in the center of the drill bit main body; the flow guide part is arranged between the central air hole and the hole cavity, and the cavity is matched with the collecting pipe. The drill bit with the structure effectively avoids the impact of rock samples on the end surface of the collecting pipe, and prolongs the service life of the collecting pipe; energy loss during rock sample collection is reduced, and rock sample collection efficiency is improved; the integrity of the rock sample is ensured.)

1. A reverse circulation drill bit, characterized by: the drill bit comprises a drill bit main body (1), wherein a central air hole (c), a hole cavity (f) and a flow guide part (v) are processed in the center of the drill bit main body (1); the flow guide part (v) is a hole cavity with a gradually-increased section and a gradually-decreased section from the end of the central air hole (c), and is arranged between the central air hole (c) and the hole cavity (f), and the hole cavity (f) is matched with the collecting pipe (22).

2. A reverse circulation drill bit according to claim 1, wherein: the extension line (L1) of the side wall (L) of the flow guide part (v) can penetrate through the structure of the end surface (D) of the collecting pipe, so that the fluid moves to the collecting pipe (22) along the side wall of the flow guide part (v).

3. A reverse circulation drill bit according to claim 1, wherein: the side wall (L) of the flow guide part (v) extends to the position of the end surface (D) of the collecting pipe, the diameter H2 is not more than H1, and H1 is the inner diameter of the collecting pipe (22).

Technical Field

The invention relates to a reverse circulation drill bit, and belongs to the technical field of drill bits.

Background

The reverse circulation rock drilling technology and the down-the-hole rock drilling technology are common rock drilling technologies, and both of the reverse circulation rock drilling technology and the down-the-hole rock drilling technology are used for carrying out rock drilling and drilling by matching a corresponding drill bit with a percussion device. The reverse circulation rock drilling technology is mainly characterized in that rock powder is discharged to the ground surface from the inside of the impactor, the formed hole wall can be effectively protected, rock sample particles can be effectively collected, and the reverse circulation rock drilling technology is widely applied to engineering construction such as prospecting and mining.

FIG. 1 is a schematic diagram of powder discharge during operation of a conventional reverse circulation impactor and a reverse circulation drill bit; in the working process, compressed gas is blown to the bottom of a hole along an air passage a at the outer edge of the reverse circulation drill bit, the compressed rock sample passes through the bottom of the hole and is connected with external rock sample collecting equipment through a drill bit end face air hole b, a central air hole c, a hole cavity d, a collecting pipe 22 central air hole e and an adaptive pipe 23 central air hole m, the adaptive pipe 23 is connected with the external rock sample collecting equipment, the rock sample passes through the reverse circulation drill bit 1 and an inner channel of the impactor 2 from the bottom of the hole and reaches the collecting equipment, and the whole process is a 'outside-in' central hole type reverse circulation process of the rock sample.

Fig. 2 is a schematic view showing the fluid enlargement at the fitting of the bore d of the drill bit and the collection tube 22. Part of the mixed fluid formed by the compressed gas and the rock sample is flushed to the end face of the collecting pipe through the central hole c and the hole cavity d to form a vortex, so that the local loss of mechanical energy is formed, and the rock powder collecting efficiency is reduced; impact with the end face of the collecting pipe can reduce rock sample particles, influence the quality of the rock sample and accelerate the abrasion of the collecting pipe and a hole matched with the drill bit and the collecting pipe.

Disclosure of Invention

The invention aims to provide a reverse circulation drill bit, which effectively avoids the impact of a rock sample on the end surface of a collecting pipe and prolongs the service life of the collecting pipe by adopting the drill bit with the structure; energy loss during rock sample collection is reduced, and rock sample collection efficiency is improved; the integrity of the rock sample is ensured.

In order to achieve the technical features, the invention is realized as follows: a reverse circulation drill bit comprises a drill bit main body, wherein a central air hole, a hole cavity and a flow guide part are processed in the center of the drill bit main body; the flow guide part is a hole cavity with a gradually-increased cross section and a gradually-decreased cross section from the end of the central air hole, and is arranged between the central air hole and the hole cavity, and the cavity is matched with the collecting pipe.

The extension line of the side wall of the flow guide part can penetrate through the end face structure of the collecting pipe, so that fluid moves towards the collecting pipe along the side wall of the flow guide part.

The side wall of the flow guide part extends to the end face of the collecting pipe, the diameter H2 is not more than H1, and H1 is the inner diameter of the collecting pipe.

The impactor comprises any one reverse circulation drill bit, and the reverse circulation drill bit is adopted in the impactor.

The invention has the following beneficial effects:

1. through adopting the drill bit of above-mentioned structure, the effectual rock specimen of having avoided has improved the life of collecting pipe to the impact of collecting pipe terminal surface.

2. Through the water conservancy diversion effect of foretell water conservancy diversion portion, can directly get into after the rock specimen direction and receive the pipe, energy loss when reducing the rock specimen and gathering has improved the collection efficiency of rock specimen.

3. Through foretell water conservancy diversion portion, avoid the rock specimen direct with the collecting pipe terminal surface contact impact, guaranteed the integrality of rock specimen.

4. Through adopting the drill bit of above-mentioned structure, the effectual rock specimen that has reduced has improved the life of drill bit to the wearing and tearing in drill bit and collecting pipe complex hole.

Drawings

The invention is further illustrated by the following figures and examples.

FIG. 1 is a schematic diagram of the powder discharge of a conventional reverse circulation impactor and reverse circulation drill bit during operation.

FIG. 2 is a schematic view showing the fluid enlargement at the fitting of the bore of the drill bit and the collecting pipe in the prior art.

FIG. 3 is a schematic view of the drill bit of the present invention.

FIG. 4 is a schematic diagram of the powder discharge of the reverse circulation impactor and reverse circulation drill bit of the present invention during operation.

FIG. 5 is an enlarged view of a portion of the reverse circulation impactor and reverse circulation drill bit of the present invention during operation.

FIG. 6 is a schematic view showing the fluid enlargement at the fitting of the bore of the drill bit and the collection tube according to the present invention.

Detailed Description

Embodiments of the present invention will be further described with reference to the accompanying drawings.