Reverse circulation deslagging drill bit

Abstract

According to the reverse circulation deslagging drill bit, a forward deslagging groove is formed in the periphery of the top of a drill body and is not directly communicated with the back of the drill bit, so that muck is blocked and can only be discharged to a deslagging branch channel; and torsion increase caused by discontinuous vacancy between the drilling tool and the hole wall is reduced. A high-pressure air hole is formed in the drill body connecting key groove, gas is jetted to blow muck outwards, and the muck smoothly enters the main deslagging channel from the branched deslagging channel. The reverse slag discharging groove is formed in the rotating front face of the forward slag discharging opening, slag enters the reverse slag discharging groove and enters the inward slag discharging main channel or falls to the bottom of a hole through rotation of a drilling tool, the situation that the slag cannot be discharged is avoided, and the drilling tool is lifted smoothly. The drilling tool is characterized by adopting the principle of slag conglomeration of a positive circulation drilling tool, the characteristic of outward slag throwing through rotation and centrifugation of the drilling tool and the natural characteristic of much slag on the periphery of the drilling tool. And the peripheral slag discharge groove is not directly communicated with the back, and guides the slag to enter the slag discharge channel of the inner hole to be discharged. The problems that an existing reverse circulation drill bit muck is difficult to collect and discharge, drill lifting is difficult, and drill jamming is prone to occurring are solved.

Description

Technical Field

[0001] The utility model relates to a reverse circulation slag discharging bit, belonging to the technical field of drilling devices. Background Art

[0002] At present, for large-diameter drilling projects in many mining areas, roller bits or cemented carbide bits are generally used for construction. In recent years, in order to solve the problem of low drilling efficiency in hard rock formations, the air down-the-hole hammer drilling technology has been introduced. Air down-the-hole hammer drilling is a drilling method that uses high-pressure air to drive the down-the-hole hammer to break rocks and simultaneously serves as the flushing medium. It is an efficient drilling method and is increasingly applied in construction.

[0003] Air down-the-hole hammer drilling can be divided into positive circulation drilling and reverse circulation drilling according to the circulation mode of the flushing medium. Positive circulation drilling is that high-pressure air is transported into the bottom of the well through the inner hole of the drill string, carrying the muck and returning upward through the annulus between the drill string and the borehole wall. The advantage of this process is that the drill tool configuration is simple, and it can be achieved by using a positive circulation down-the-hole hammer and supporting relevant single-wall drill tools. It has good durability and low use and maintenance costs. However, the disadvantages are also obvious. That is, the flushing medium returns directly from the borehole, and its upward return speed is affected by the borehole diameter, so the formed hole diameter is generally small. The upward-returning medium cannot be effectively collected, and the construction environment is poor. Moreover, in case of broken or collapsed formations or large fractures in the annulus, positive circulation drilling cannot be smoothly achieved. Reverse circulation drilling is that high-pressure air is transported into the bottom of the well through the annulus channel of the double-wall drill pipe, carrying the muck and then the flushing medium returns upward through the central channel of the double-wall drill pipe. The upward return speed of the flushing medium in this process has nothing to do with the borehole diameter. In addition, the borehole wall is not scoured by the upward-returning medium, and even in case of broken and collapsed formations, drilling can be smoothly carried out. However, the impact force generated when the reverse circulation drill tool air down-the-hole hammer works will disperse the muck at the bottom and around the borehole, and the dispersibility of the muck increases the difficulty of concentrating and sucking it into the drill pipe interior, making it difficult to collect the muck inwardly. For large-diameter drilling, slag discharging is difficult. And due to the action of the pneumatic impact force, the rock fragments broken by the large-diameter pneumatic reverse circulation down-the-hole hammer are larger, resulting in an increase in the slag discharging difficulty. Summary of the Utility Model

[0004] The purpose of the utility model is to provide a reverse circulation slag discharging bit with a unique channel, which can solve the slag discharging problem of current reverse circulation drill tools.

[0005] The technical solution adopted by the present utility model is as follows: An anti-circulation slag discharging drill bit, comprising a drill body, wherein a plurality of first alloy tooth heads are provided at the top of the drill body, a forward slag discharging groove is formed in the outer periphery of the top of the drill body, and the forward slag discharging groove penetrates forward; a main slag discharging channel extending towards the top and not penetrating is formed at the bottom of the drill body, and each forward slag discharging groove is connected to the main slag discharging channel through a branch slag discharging channel; a high-pressure air hole is further formed in the drill body, one end of the high-pressure air hole is arranged radially inside the forward slag discharging groove and communicated with the forward slag discharging groove, and the other end of the high-pressure air hole is located at the rear side of the forward slag discharging groove and communicated with the outside of the drill body.

[0006] Optionally, there are a plurality of the forward slag discharging grooves, and the plurality of forward slag discharging grooves are arranged at intervals in the circumferential direction.

[0007] Optionally, a slag discharging inclined groove is provided at the top of the drill body and arranged radially outwards, the radial outer side of the slag discharging inclined groove leads to the forward slag discharging groove, and it gradually becomes deeper towards the forward slag discharging groove.

[0008] Optionally, one end of the high-pressure air hole is directly communicated with the slag discharging inclined groove and indirectly communicated with the forward slag discharging groove through the slag discharging inclined groove.

[0009] Optionally, the high-pressure air hole comprises a first hole section and a second hole section which are connected and penetrated, both the first hole section and the second hole section are inclined, and the openings of the first hole section and the second hole section both face radially outwards.

[0010] Optionally, a plurality of reverse slag discharging grooves arranged at intervals in the circumferential direction are further formed in the outer periphery of the top of the drill bit, the reverse slag discharging grooves penetrate backwards, and the reverse slag discharging grooves are communicated with the forward slag discharging grooves.

[0011] Optionally, the reverse slag discharging grooves and the forward slag discharging grooves are arranged in a circumferential and axial dislocation manner, and the reverse slag discharging grooves are located behind the forward slag discharging grooves.

[0012] Optionally, the rear end surface between the forward slag discharging grooves is an inclined surface inclined towards the reverse slag discharging grooves.

[0013] Optionally, the branch slag discharging channels are arranged radially inside the forward slag discharging grooves, the radial width of the reverse slag discharging grooves is smaller than that of the forward slag discharging grooves, and the radial outer sides of the reverse slag discharging grooves and the forward slag discharging grooves are flush.

[0014] Optionally, a second alloy tooth head is provided on the outer side surface of the reverse slag discharging groove.

[0015] In summary, due to the adoption of the above technical solution, the beneficial effects of the present utility model are as follows:

[0016] 1. The reverse circulation slag discharging bit provided by the utility model arranges the forward slag discharging groove on the outer periphery of the top of the drill body, and then uses the slag discharging branch channel to connect the forward slag discharging groove on the outer periphery and the main slag discharging channel in the center, converging to the main slag discharging channel. Adopting the principle of positive circulation slag accumulation, the characteristics of the drill tool rotating and centrifugally throwing slag outward, and the natural characteristics of a large amount of muck around the drill tool, the muck moves radially outward and accumulates in the forward slag discharging groove. The muck in the forward slag discharging groove then leads to the main slag discharging channel through the slag discharging branch channel, that is, it returns upward through the central channel of the drill pipe. It not only collects muck through the forward slag discharging groove on the outer periphery, having the advantages of positive circulation slag accumulation, but also uses the main slag discharging channel for the upward return of muck, having the advantages of stronger muck carrying capacity in reverse circulation, thus solving the problem that it is difficult to collect muck in existing reverse circulation bits.

[0017] 2. For the reverse circulation slag discharging bit provided by the utility model, the muck broken by the vibration of the drill tool directly enters the slag discharging inclined groove from the outer inclined slag discharging groove on the end face of the drill tool. The forward slag discharging groove does not completely lead to the back of the drill tool and is blocked by the bottom surface of the groove. Moreover, there is not much space between the outer periphery of the drill tool and the hole wall, so the muck can only be discharged by releasing pressure through the slag discharging branch channel. When retrieving the drill tool, if there is a phenomenon of hole wall collapse, there is alloy on the reverse inclined plane of the drill tool. When the drill tool rotates to break stones, when the stones are smaller than the reverse slag discharging groove, they enter the slag discharging branch channel and are discharged clockwise.

[0018] 3. For the reverse circulation slag discharging bit provided by the utility model, the forward slag discharging groove and the reverse slag discharging groove are arranged in a staggered layout. There is no axial vacant through-hole on the outer periphery of the drill tool, so it is not easy to get stuck. Moreover, there is no completely channel-shaped notch on the outer circle of the drill tool, which can make the force received by the drill tool during drilling more dispersed and uniform, reducing the increase in torque caused by intermittent vacancies between the drill tool and the hole wall. In addition, there is a shield behind the slag discharging branch channel to prevent muck from accumulating behind the drill tool. The forward slag discharging groove is connected to the reverse slag discharging groove. When the muck of the hole wall collapses during drill lifting, the muck enters the forward slag discharging groove from the reverse slag discharging groove, then either enters the slag discharging branch channel or drops to the bottom of the hole through the forward slag discharging groove, enabling smooth drill lifting. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is the front view of the utility model.

[0020] Figure 2 is the top view of the utility model.

[0021] Figure 3 is the top view of the utility model Figure 2 .

[0022] Figure 4 is the bottom view of the utility model.

[0023] Markings in the figure: 1 - drill body, 2 - first alloy bit head, 3 - forward slag discharge groove, 4 - main slag discharge channel, 5 - branch slag discharge channel, 6 - high-pressure air hole, 61 - first hole section, 62 - second hole section, 7 - inclined slag discharge groove, 8 - reverse slag discharge groove, 9 - second alloy bit head. Detailed implementation mode

[0024] The following combines the attached drawings to make a detailed description of the present utility model.

[0025] In order to make the purpose, technical solution and advantages of the present utility model clearer, the following further details the present utility model in combination with the attached drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present utility model and are not used to limit the present utility model.

[0026] In the description of the embodiments of the present utility model, it should be understood that the terms "front" and "top" refer to the drilling direction of the drill bit, that is, Figure 1 the upper part in Figure 1 and the terms "rear" and "bottom" refer to the retraction direction of the drill bit, that is,

[0027] A reverse circulation slag discharge drill bit, as Figures 1-4 shown, includes a drill body 1, a plurality of first alloy bit heads 2 are provided at the top of the drill body 1, a forward slag discharge groove 3 is opened on the outer periphery of the top of the drill body 1, and the forward slag discharge groove 3 penetrates forward; a high-pressure air hole 6 is also opened in the drill body 1, one end of the high-pressure air hole 6 is communicated with the forward slag discharge groove 3, and the other end of the high-pressure air hole 6 is located at the rear side of the forward slag discharge groove 3 and is communicated with the outside of the drill body 1; a main slag discharge channel 4 extending upward and not penetrating is opened at the bottom of the drill body 1, and each forward slag discharge groove 3 is connected to the main slag discharge channel 4 through a branch slag discharge channel 5.

[0028] Specifically, when the drill bit rotates and impacts the rock, crushed soil will be generated around it. Due to the rotation of the drill bit, these crushed soils move radially outward through rotational centrifugation. In this solution, a forward slag discharge groove 3 is provided on the outer periphery of the top of the drill bit. There is no channel between the outer periphery of the drill tool and the hole wall. The crushed soils gather in the forward slag discharge groove 3, and the forward slag discharge groove 3 is connected to the main slag discharge channel 4 through a slag discharge branch channel 5. Finally, the crushed soils in the forward slag discharge groove 3 lead to the main slag discharge channel 4 through the slag discharge branch channel 5, that is, they return upward through the central channel of the drill pipe. In addition, a high-pressure air hole 6 is provided at the connection keyway, communicating from the rear side to the top of the drill body 1 to provide high-pressure gas and form a certain flow velocity distribution in the drill hole. The flow velocity decreases from the high-pressure air hole 6 towards the forward slag discharge groove 3. This flow velocity difference will cause the crushed soils to move towards the area with a lower flow velocity, that is, the forward slag discharge groove 3. Among them, there is a chamfer between the forward slag discharge groove 3 and the slag discharge branch channel 5 to facilitate the flow of the crushed soils. Further, both the high-pressure air hole 6 and the slag discharge branch channel 5 are inclined, and their slopes can be set according to actual situations. Straight holes, inclined holes, and bent holes can be used. Preferably, when there are multiple high-pressure air holes 6 and slag discharge branch channels 5, different slopes and different connection positions can be adopted between the high-pressure air holes 6 and the slag discharge branch channels 5, which can improve the air flow coverage area and prevent blockage when the air flow or crushed soils gather at the same position.

[0029] As another specific embodiment, the high-pressure air hole 6 includes a first hole section 61 and a second hole section 62 that are connected and penetrated. Both the first hole section 61 and the second hole section 62 are inclined, and the openings of the first hole section 61 and the second hole section 62 both face radially outward. Through this setting, the air outlet direction of the high-pressure air hole 6 faces radially outward, which can use the outward air flow to drive the crushed soils to move outward and then enter the forward slag discharge groove 3. Further, the first hole section 61 and the second hole section 62 are arranged in a V shape in the circumferential direction to avoid affecting the structure of the drill body 1 due to the opening.

[0030] As another specific embodiment, there are multiple forward slag discharge grooves 3, and the multiple forward slag discharge grooves 3 are arranged at intervals in the circumferential direction. If there is only one forward slag discharge groove 3, the risk of slag blockage is relatively high. Multiple forward slag discharge grooves 3 can reduce this risk because even if one forward slag discharge groove 3 is partially blocked, the others can still continue to discharge slag, thereby improving the overall slag discharge efficiency. And it helps to reduce the accumulation of crushed soils at the bottom of the drill hole, avoid repeated crushing and reduce the drilling speed. In addition, it can also distribute the air flow more evenly to ensure that the crushed soils in each area at the bottom of the drill hole can be effectively blown up and carried.

[0031] As another specific embodiment, a slag discharge chute 7 is provided at the top of the drill body 1 and is arranged radially outward. The radial outer side of the slag discharge chute 7 leads to the forward slag discharge chute 3 and gradually deepens towards the forward slag discharge chute 3. Among them, the radial arrangement of the chute helps the muck to move along the chute under the action of centrifugal force and thus be discharged. The design of gradually deepening the slag discharge chute 7 can guide the muck to flow from the working surface of the drill bit to the forward slag discharge chute 3. As the depth of the chute increases, the flow rate of the muck in the chute will also increase, which helps to improve the slag discharge efficiency.

[0032] As another specific embodiment, one end of the high-pressure air hole 6 is directly communicated with the slag discharge chute 7 and is indirectly communicated with the forward slag discharge chute 3 through the slag discharge chute 7. By connecting the slag discharge chute 7 with the high-pressure air hole 6, the air flow can form a continuous flow path inside the drill bit, which helps to ensure that the air flow can be evenly distributed throughout the drill bit instead of concentrating in a certain area. And when the air flow flows out from the slag discharge chute 7, it can generate enough momentum to carry the muck to move along the slag discharge chute 7.

[0033] As another specific embodiment, a plurality of reverse slag discharge chutes 8 are also provided on the outer periphery of the top of the drill bit and are arranged at intervals in the circumferential direction. The reverse slag discharge chutes 8 penetrate backward, and the reverse slag discharge chutes 8 are communicated with the forward slag discharge chute 3. When a failure occurs to the drill tool or it needs to be replaced, the drill tool needs to be pulled out of the drill hole at this time. There may still be cuttings in the drill tool at this time. If reverse slag discharge is not carried out, the cuttings may block the inside of the drill tool, resulting in the drill tool being unable to be pulled out smoothly. Through reverse slag discharge, the accumulation of cuttings inside the drill tool can be avoided, the wear of the drill tool can be reduced, the service life of the drill tool can be extended, and the cuttings inside the drill tool can be quickly removed, the resistance during the pulling process of the drill tool can be reduced, and the operation efficiency can be improved. Further, the reverse slag discharge chutes 8 and the forward slag discharge chute 3 are communicated, and share the slag discharge branch channel 5 to enter the slag discharge main channel 4 for slag discharge. When reverse slag discharge is carried out, the drill tool rotates, and the muck either enters the slag discharge branch channel 5 or falls to the bottom of the hole through the forward slag discharge chute 3, and the drill tool can be lifted smoothly.

[0034] As another specific embodiment, the reverse slag discharge chutes 8 and the forward slag discharge chute 3 are arranged in a circumferential and axial dislocation manner, and the reverse slag discharge chutes 8 are located behind the forward slag discharge chute 3. In this solution, the dislocation setting is adopted, and the channel is the overlapping part of the forward slag discharge chute 3 and the reverse slag discharge chutes 8, which is small and not easy to get stuck. In addition, between the two-way slag discharge, when the muck enters the slag discharge chute, it will not leak from the other port, blocking the muck and making it more beneficial for the muck to enter the slag discharge hole and be discharged. Further, the reverse slag discharge chute is arranged in front of the rotation direction of the forward slag discharge port, and the muck enters the forward slag discharge chute 3 from the reverse slag discharge chute 8 when rotating.

[0035] As another specific embodiment, a slope transition is provided between the forward slag discharge chute 3 and the reverse slag discharge chute 8. The slope transition helps to reduce the accumulation of muck between the junctions of the forward slag discharge chute 3 and the reverse slag discharge chute 8, which helps to maintain smoothness and reduce the blockage of the drill bit caused by muck.

[0036] As another specific embodiment, the slag discharge branch channel 5 is arranged on the radially inner side of the forward slag discharge chute 3. The radial width of the reverse slag discharge chute 8 is smaller than that of the forward slag discharge chute 3, and the radial outer sides of the reverse slag discharge chute 8 and the forward slag discharge chute 3 are flush. With this solution, a stepped structure that is not connected to the reverse slag discharge chute 8 is provided in the radial direction of the forward slag discharge chute 3. By using this stepped structure to arrange the slag discharge branch channel 5, during the drilling process, the muck can enter the slag discharge branch channel 5 more smoothly along the radial direction.

[0037] As another specific embodiment, a second alloy tooth head 9 is provided on the outer side surface of the reverse slag discharge chute 8. When retrieving the drill string, if there is a phenomenon of hole wall collapse and there is alloy on the reverse inclined surface of the drill string, and if there are large stones, the second alloy tooth head 9 can perform secondary crushing on them. The drill string rotates to break the blocks, and when the stones are smaller than the reverse slag discharge chute 8, they enter the slag discharge hole and are discharged.

[0038] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. The present invention extends to any new features or any new combinations disclosed in this specification, and any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

[0039] In the description of the embodiments of the present invention, it should be understood that the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. In the description of the embodiments of the present invention, the meaning of "a plurality" is two or more unless otherwise specifically defined.

Claims

1. A reverse circulation slag removal drill bit, characterized by: The drill body (1) comprises a drill body (1), wherein a plurality of first alloy tooth heads (2) are arranged at the top of the drill body (1), and a positive slag discharge groove (3) is provided on the outer periphery of the top of the drill body (1), and the positive slag discharge groove (3) is connected forwardly; a main slag discharge channel (4) extending toward the top and not connected is provided at the bottom of the drill body (1), and each of the positive slag discharge grooves (3) is connected to the main slag discharge channel (4) via a slag discharge branch channel (5); and a high-pressure air hole (6) is also provided in the drill body (1), one end of the high-pressure air hole (6) is arranged on the radial inner side of the positive slag discharge groove (3) and is connected to the positive slag discharge groove (3), and the other end of the high-pressure air hole (6) is located at the rear side of the positive slag discharge groove (3) and is connected to the outside of the drill body (1).

2. The reverse circulation deslagging drill bit according to claim 1, characterized in that: The positive slag discharge grooves (3) include a plurality of positive slag discharge grooves (3), and the plurality of positive slag discharge grooves (3) are arranged at intervals along the circumferential direction.

3. The reverse circulation deslagging drill bit according to claim 1, characterized in that: A slag discharge chute (7) is provided at the top of the drill body (1) and is arranged radially outward. The radial outer side of the slag discharge chute (7) leads to a forward slag discharge chute (3) and gradually becomes deeper towards the forward slag discharge chute (3).

4. The reverse circulation deslagging drill bit according to claim 3, characterized in that: One end of the high-pressure air hole (6) is directly connected to the slag discharge chute (7), and is indirectly connected to the forward slag discharge chute (3) through the slag discharge chute (7).

5. The reverse circulation deslagging drill bit according to claim 1, characterized in that: The high-pressure air hole (6) comprises a first hole section (61) and a second hole section (62) which are connected and interpenetrating with each other. The first hole section (61) and the second hole section (62) are both arranged obliquely, and the openings of the first hole section (61) and the second hole section (62) are both oriented radially outward.

6. The reverse circulation deslagging drill bit according to claim 1, characterized in that: The top outer circumference of the drill bit is also provided with a plurality of reverse slag discharge grooves (8) arranged at intervals along the circumferential direction. The reverse slag discharge grooves (8) are connected backwards and are connected to the forward slag discharge grooves (3).

7. The reverse circulation deslagging drill bit according to claim 6, characterized in that: The reverse slag discharge groove (8) and the forward slag discharge groove (3) are arranged in a circumferential and axially staggered manner, and the reverse slag discharge groove (8) is located behind the forward slag discharge groove (3).

8. The reverse circulation deslagging drill bit according to claim 7, characterized in that: The forward slag discharge groove (3) and the reverse slag discharge groove (8) are transitioned by an inclined surface.

9. The reverse circulation deslagging drill bit according to claim 7, characterized in that: The slag discharge branch channel (5) is arranged on the radial inner side of the forward slag discharge groove (3), the radial width of the reverse slag discharge groove (8) is smaller than that of the forward slag discharge groove (3), and the radial outer sides of the reverse slag discharge groove (8) and the forward slag discharge groove (3) are flush.

10. The reverse circulation deslagging drill bit according to claim 6, characterized in that: The outer side surface of the reverse slag discharge groove (8) is provided with a second alloy tooth head (9).

Images