CN215804378U

CN215804378U - Reverse circulation drill bit of large-diameter air down-the-hole hammer

Info

Publication number: CN215804378U
Application number: CN202122048824.4U
Authority: CN
Inventors: 杨俊德; 龙华清
Original assignee: Changsha Zhongda Metallurgy Equipment Co ltd
Current assignee: Changsha Zhongda Metallurgy Equipment Co ltd
Priority date: 2021-08-28
Filing date: 2021-08-28
Publication date: 2022-02-11
Anticipated expiration: 2031-08-28

Abstract

The utility model discloses a reverse circulation drill bit of a large-caliber air down-the-hole hammer, which comprises a drill bit body, spherical teeth, side teeth and a collecting pipe, wherein the middle part of the drill bit body is provided with a central channel along the axis, the collecting pipe is sleeved in the central channel, the lower section of the central channel is obliquely and downwards provided with a plurality of bottom spraying channels, the tail end of the bottom spray channel is arranged on the side end face of the drill bit body, the side end face of the drill bit body is provided with a diversion trench corresponding to the bottom spray channel, the bottom of the drill bit body is provided with a plurality of slag discharging channels communicated with the collecting pipe, the bottom end of the drill bit body is provided with a slag discharging groove communicated with the diversion trench, the slag discharging groove is communicated with the slag discharging channel, the bottom end of the drill bit body is a concave surface, the spherical teeth are uniformly arranged on the concave surface, the edge part of the bottom end of the drill bit is arranged in an inclined plane, the side teeth are evenly arranged on the inclined plane, and the collecting pipe is provided with an inner spraying channel which is opposite to the bottom spraying channel and is inclined reversely.

Description

Reverse circulation drill bit of large-diameter air down-the-hole hammer

Technical Field

The utility model relates to the technical field of drilling, in particular to a reverse circulation drill bit of a large-diameter air down-the-hole hammer.

Background

At present, large-aperture drilling engineering in many mining areas is generally constructed by using a roller bit or a hard alloy bit, in order to solve the problem of low drilling efficiency of hard rock layers in recent years, an air down-the-hole hammer forward circulation drilling technology is introduced, and an air down-the-hole hammer reverse circulation drilling technology is adopted on the basis of forward circulation of the air down-the-hole hammer for solving the problems that a drill hole is easy to collapse or even scrap during construction of a complex stratum, slag is difficult to remove due to increase of the depth of the drill hole and dust pollution is caused when rock dust is discharged, but in the actual construction process, the problems that an air down-the-hole hammer reverse circulation drilling bit used in the market at present is small in diameter, the drilled hole is small in diameter, the bottom airflow hole sweeping range of the drill hole is small, slag removal and cooling of side teeth of the drill bit are not facilitated, and the drilling efficiency is low are found.

Therefore, a reverse circulation drill bit of the air down-the-hole hammer with large caliber, large bottom airflow hole-sweeping area, high efficiency and high quality is needed to be designed.

Disclosure of Invention

Technical problem to be solved

Aiming at the defects of the prior art, the utility model provides a large-diameter reverse circulation drill bit for an air down-the-hole hammer, which solves the problems that the conventional reverse circulation drill bit for the air down-the-hole hammer, which is used by people, is not beneficial to slag discharge and cooling of side teeth of the drill bit and low drilling efficiency because the diameter of the drill bit is small and the hole bottom airflow hole sweeping range is small during construction.

(II) technical scheme

In order to achieve the purpose, the utility model is realized by the following technical scheme: a reverse circulation drill bit of a large-caliber air down-the-hole hammer comprises a drill bit body, spherical teeth, side teeth and a collecting pipe, wherein the middle part of the drill bit body is provided with a central channel along the axis, the collecting pipe is sleeved in the central channel, the lower section of the central channel is obliquely and downwards provided with a plurality of bottom spraying channels, the tail end of the bottom spray channel is arranged on the side end face of the drill bit body, the side end face of the drill bit body is provided with a diversion trench corresponding to the bottom spray channel, the bottom of the drill bit body is provided with a plurality of slag discharging channels communicated with the collecting pipe, the bottom end of the drill bit body is provided with a slag discharging groove communicated with the diversion trench, the slag discharging groove is communicated with the slag discharging channel, the bottom end of the drill bit body is a concave surface, the spherical teeth are uniformly arranged on the concave surface, the edge part of the bottom end of the drill bit is arranged in an inclined plane, the side teeth are evenly arranged on the inclined plane, and the collecting pipe is provided with an inner spraying channel which is opposite to the bottom spraying channel and is inclined reversely.

Preferably, the number of the bottom spraying channels is four, the bottom spraying channels are uniformly distributed along the circumference, and the included angle between the central axis of each bottom spraying channel and the central axis of the drill bit body is 40-50 degrees.

Preferably, the bottom of the drill bit is centrally and symmetrically provided with a slag discharge channel.

Preferably, four slag discharge grooves are arranged, the included angle between each slag discharge groove and the axis of the bottom end of the drill bit is 15-30 degrees, and the two slag discharge grooves form a group and are communicated with one slag discharge channel.

Preferably, the inclined planes comprise a first inclined plane and a second inclined plane, the included angle between the first group of inclined planes and the bottom surface of the drill bit is 28-32 degrees, and the included angle between the second group of inclined planes and the bottom surface of the drill bit is 33-37 degrees.

Preferably, the number of the spherical teeth increases from inside to outside in sequence, and the spherical teeth are not close to the exhaust hole.

Preferably, the included angle between the concave surface and the bottom surface of the drill bit is 5-10 degrees.

Preferably, the diameter of the slag inlet port of the slag discharge channel is smaller than the diameter of the connecting end of the slag discharge channel and the collection pipe.

Preferably, smooth circular arc transition is adopted at all corners.

(III) advantageous effects

The utility model provides a reverse circulation drill bit of a large-diameter air down-the-hole hammer. The method has the following beneficial effects:

according to the utility model, the gas outlet of the bottom spraying channel is arranged on the side end face of the drill bit, so that high-pressure gas moves to the slag discharge channel along the flow guide groove and the slag discharge groove, the hole sweeping area of the high-pressure gas is greatly enlarged, the abrasion of the end part of the drill bit body is reduced, and the cooling effect on the side teeth is enhanced.

According to the utility model, through the internal injection channel reversely designed on the collection pipe, secondary injection can be formed, and the suction effect is further enhanced.

The utility model effectively increases the area and the cooling effect of the air flow scavenging hole through the slag discharging groove and the two slag discharging channels which are obliquely arranged, reduces the mutual interference between high-speed fluids, and forms local negative pressure by adopting a gradually expanding structure with a small lower part and a big upper part to generate stronger entrainment effect.

According to the utility model, the drill hole can be prevented from inclining by adopting the concave form on the bottom surface of the drill bit body, and the stress condition of the side teeth can be improved by adopting the double-side tooth structure on the edge part of the bottom end of the drill bit body, so that the side teeth are prevented from being broken or fatigue failure occurs in advance, and the service life of the drill bit is shortened.

Drawings

FIG. 1 is a first cross-sectional view of the present invention;

FIG. 2 is a structural diagram of the working end face in a toothless state according to the present invention;

FIG. 3 is a schematic view of a toothed structure of the working end face of the present invention;

FIG. 4 is a schematic cross-sectional view of the present invention;

FIG. 5 is an enlarged view of the structure of the present invention at A.

In the figure, a drill body 1, a collecting pipe 2, a bottom end edge part 3, a central channel 4, a bottom spraying channel 5, a flow guide groove 6, a slag discharge groove 7, a slag discharge channel 8, a concave surface 9, an inner spraying channel 10, a spherical tooth 11, a side tooth 12, a first inclined surface 13 and a second inclined surface 14 are arranged.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the 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. 1-5, (fig. 1 is a schematic structural view of an omitted internal spray channel, and fig. 4 is a schematic structural view of an unreleased internal spray channel) the embodiment of the present invention provides a technical solution: a large-caliber air down-the-hole hammer reverse circulation drill bit comprises a drill bit body 1, a spherical tooth 11, a side tooth 12 and a collecting pipe 2, wherein a central channel 4 is formed in the middle of the drill bit body 1 along an axis, the collecting pipe 2 is sleeved in the central channel 4 (an air inlet channel is formed by the outer wall of the collecting pipe 2 and the inner wall of the central channel 4, high-pressure gas moves downwards from the air inlet channel), a plurality of bottom spraying channels 5 are obliquely and downwards formed in the lower section of the central channel 4, the tail ends of the bottom spraying channels 5 are arranged on the side end face of the drill bit body 1, a diversion trench 6 is formed in the side end face of the drill bit body 1 corresponding to the bottom spraying channels 5, a plurality of slag discharging channels 8 communicated with the collecting pipe 2 are formed in the bottom of the drill bit body 1, a slag discharging groove 7 communicated with the diversion trench 6 is formed in the bottom end of the drill bit body 1 (the slag discharging groove 7 is equivalent to a pressure expansion chamber, and the high-pressure gas forms a pressure difference around the bottom spraying channels 5, guiding the airflow at the bottom of the drill hole to move towards a slag discharge channel 8 at the bottom of the drill bit at a high speed to form a strong suction effect and take away all the rock powder after the surrounding crushing), wherein the slag discharge groove 7 is communicated with the slag discharge channel 8 (the high-pressure gas is sprayed out from the bottom spray channel 5 and moves towards the slag discharge channel 8 along the diversion trench 6 and the slag discharge groove 7, so that the hole sweeping area of the high-pressure gas is greatly enlarged, the high-pressure gas can take away the rock debris at the bottom of the drill bit, the rock debris on the side wall of the end part of the drill bit can be discharged in time, the abrasion of the end part of the drill bit 1 is reduced, the cooling effect on the teeth 12 is better), the bottom end of the drill bit 1 is a concave surface 9 (the drilling inclination can be prevented due to the design of the concave surface 9), and the spherical teeth 11 are uniformly arranged on the concave surface 9 (the spherical teeth 11 are arranged according to a concentric circle on the concave surface 9, the interval of each circle should be smaller than the diameter of the spherical teeth 11, and the number of each circle can be determined according to the same volume crushing principle), the edge portion 3 of the bottom end of the drill bit is arranged on an inclined plane, the side teeth 12 are evenly arranged on the inclined plane, the collecting pipe 2 is provided with an internal spraying channel 10 corresponding to the bottom spraying channel 5 and inclined reversely, the internal spraying channel 10 is favorable for secondary injection, the suction effect is further enhanced, mixed fluid in the central channel 4 is guided to continue to move upwards, and the reverse circulation deslagging effect is better.

The number of the bottom spray channels 5 is four, the bottom spray channels are uniformly distributed along the circumference, and the included angle between the central axis of the bottom spray channels 5 and the central axis of the drill bit body 1 is 40-50 degrees.

The four slag discharge grooves 7 are arranged, the included angle between each slag discharge groove 7 and the axis of the bottom end of the drill bit is 15-30 degrees, the two slag discharge grooves 7 are communicated with one slag discharge channel 8 in a group, the slag discharge grooves 7 are obliquely arranged (the included angle is formed between the slag discharge grooves and the axis of the bottom end), each slag discharge groove 7 corresponds to the bottom spraying channel 5, the length of each slag discharge groove 7 is increased by the aid of an oblique arrangement mode, the increase of the length means that the area of an air flow sweeping hole is larger and more thorough, broken rock powder can be smoothly discharged in time, meanwhile, the drill bit is cooled more sufficiently, and in addition, the two slag discharge grooves 7 are communicated with one slag discharge channel 8 in a group, and mutual interference between high-speed fluids can be reduced.

The inclined planes comprise a first inclined plane 13 and a second inclined plane 14, the included angle between the first group of inclined planes 13 and the bottom surface of the drill bit is 28-32 degrees, the included angle between the second group of inclined planes 14 and the bottom surface of the drill bit is 33-37 degrees, the side teeth 12 are uniformly arranged on the inclined planes, and the side teeth 12 (both spherical teeth and side teeth are conventional technologies) are arranged mainly for reducing the abrasion of rocks to the outer circumference of the drill bit body 1 and have the anti-blocking effect. Because the stress condition of the side teeth 12 at the bottom of the hole is complex, the stress condition of the side teeth needs to be improved by adjusting the angle of the outer inclined surface of the drill bit body in the design process (the larger the camber angle of the drill bit body 1 is, the larger the bending stress born by the stud is, the structure of double inclined surfaces is adopted for hard rock crushing, the structure of the double side teeth 12 is arranged, two groups of inclination angles are designed, the shearing component of the side teeth 12 is properly increased while the axial component of the side teeth 12 is slightly reduced as much as possible, and finally, two groups of side teeth 12 are adopted), so that the side teeth 12 are prevented from being broken or fatigue failure occurs in advance, the service life of the drill bit is prevented from being reduced, the number of the side teeth 12 can be properly increased for a large-caliber reverse circulation drill bit, and the load and abrasion of the side teeth 12 are reduced.

The numbers of the spherical teeth 11 are sequentially increased from inside to outside (sequentially increased according to the linear velocity and the abrasion degree of the spherical teeth 11), the spherical teeth 11 are not close to the slag discharging channel 8, the stress between the tooth holes and the slag discharging channel 8 is prevented from being small, the spherical teeth 11 are prevented from falling off, the spherical teeth 11 are uniformly distributed, the intervals are equal, and the impact energy obtained by each circle of spherical teeth is uniform.

The included angle between the concave surface 9 and the bottom surface of the drill bit is 5-10 degrees.

The diameter of the slag inlet end of the slag discharging channel 8 is smaller than the diameter of the connecting end of the slag discharging channel 8 and the collecting pipe 2, a gradually-expanding structure with a small lower part and a large upper part of the slag discharging channel 8 is formed, so that a local negative pressure is formed, and a stronger entrainment effect is generated due to the fact that the air speed is higher.

And all corners adopt smooth arc transition, so that the kinetic energy loss of airflow is reduced.

The working principle of the utility model is as follows: the high-pressure gas moves downwards from the gap between the central passage 4 and the collecting pipe 2, one air flow passes through the inner spraying passage 10 and moves upwards in the collecting pipe 2 in an inclined mode to form injection, the other air flow passes through the bottom spraying passage 5 and is sprayed out from the side end face of the drill bit body 1, rock debris on the side wall of the end of the drill bit and rock debris at the bottom of the drill bit are flushed to the slag discharging passage 8 while moving to the slag discharging passage 8 after passing through the flow guide groove 6 and the slag discharging groove 7, abrasion of the end of the drill bit body 1 is reduced, the cooling effect on the side teeth 12 is better, due to the negative pressure effect, the rock debris move to the collecting pipe 2 from the slag discharging passage 8 and move upwards until the collecting pipe 2 is flushed out after entering the collecting pipe 2.

It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the utility model, the scope of which is defined in the appended claims and their equivalents.

Claims

1. The large-caliber air down-the-hole hammer reverse circulation drill bit is characterized by comprising a drill bit body, spherical teeth, side teeth and a collecting pipe, wherein a central channel is formed in the middle of the drill bit body along the axis, the collecting pipe is sleeved in the central channel, a plurality of bottom spraying channels are obliquely and downwards formed in the lower section of the central channel, the tail ends of the bottom spraying channels are arranged on the side end face of the drill bit body, a flow guide groove is formed in the side end face of the drill bit body corresponding to the bottom spraying channels, a plurality of slag discharging channels communicated with the collecting pipe are formed in the bottom of the drill bit body, slag discharging grooves communicated with the flow guide grooves are formed in the bottom end of the drill bit body, the bottom end of the drill bit is a concave surface, the spherical teeth are uniformly arranged on the concave surface, the edge part of the bottom end of the drill bit is an inclined surface, and the side teeth are uniformly arranged on the inclined surface, an inner spraying channel is formed on the collecting pipe in a reverse inclined mode corresponding to the bottom spraying channel.

2. The large-caliber air down-the-hole hammer reverse circulation drill bit as claimed in claim 1, wherein the bottom spray channels are provided in four and uniformly distributed along the circumference, and the included angle between the central axis of the bottom spray channels and the central axis of the drill bit body is 40-50 degrees.

3. The large-caliber air down-the-hole hammer reverse circulation drill bit as claimed in claim 1, wherein the bottom of the drill bit is centrally symmetrically provided with a slag discharge channel.

4. The large-caliber air down-the-hole hammer reverse circulation drill bit as claimed in claim 3, wherein four slag discharge grooves are arranged, the included angle between the slag discharge groove and the axis of the bottom end of the drill bit is 15-30 degrees, and two slag discharge grooves are in a group and are communicated with one slag discharge channel.

5. The large-caliber air down-the-hole hammer reverse circulation drill bit according to claim 1, wherein the inclined planes comprise a first inclined plane and a second inclined plane, the included angle between the first group of inclined planes and the bottom surface of the drill bit is 28-32 degrees, and the included angle between the second group of inclined planes and the bottom surface of the drill bit is 33-37 degrees.

6. The reverse circulation drill bit of the large-caliber air down-the-hole hammer according to claim 1, wherein the number of the spherical teeth increases from inside to outside in sequence, and the spherical teeth are not adjacent to the exhaust hole.

7. The large-caliber air down-the-hole hammer reverse circulation drill bit as claimed in claim 1, wherein the included angle between the concave surface and the bottom surface of the drill bit is 5-10 °.

8. The large-caliber air down-the-hole hammer reverse circulation drill bit according to claim 1, wherein the diameter of a slag inlet port of the slag discharge channel is smaller than the diameter of the connecting end of the slag discharge channel and the collection pipe.

9. A heavy caliber air down-the-hole hammer drill bit according to claim 1, wherein smooth rounded transitions are used at all corners.