A mine directional drilling bit with active check valve

Abstract

The utility model relates to a mine directional drill bit of initiative non -returning slag body, including drill bit body, and the cutter head of installing at drill bit body front end, be equipped with drilling fluid channel in the drill bit body, install initiative non -returning mechanism in the drilling fluid channel, initiative non -returning mechanism opens along the drilling fluid work flow direction, closes along the reverse direction of drilling fluid work flow direction. The utility model discloses through setting initiative non -returning mechanism, can guarantee the flow of drilling fluid when normal operation, also avoided the coal slag backflow to screw motor after operation stop, and need not set up independent non -returning drill rod, simplified the drilling assembly structure, has relieved the drilling system head weight.

Description

Technical Field

[0001] This utility model relates to the field of mining equipment technology, and in particular to a directional drill bit device for drilling construction of directional drilling rigs in coal mines, specifically a mining directional drill bit for actively preventing the backflow of slag. Background Technology

[0002] In underground drilling operations in coal mines, conventional drill bits typically require the use of additional check rods to prevent coal slag, mud, and other debris from flowing back into the screw motor when drilling stops, potentially damaging the motor. This structure increases the length and weight of the drill string assembly, making operation inconvenient, and the check rod effect is not ideal under complex geological conditions. Existing drill bits have poor water cooling performance, easily causing the PDC composite cutting teeth to wear or fall off due to high temperatures, reducing their service life. Furthermore, the threaded connection between the drill bit and drill rod is prone to breakage due to stress concentration, and the overall structure is complex, making maintenance and replacement difficult.

[0003] For example, when drilling through soft, fractured rock formations, the large amount of cuttings generated by the increased drilling speed can easily clog the water passages of the drill bit, leading to poor cuttings removal and drill bit cooling failure. This necessitates frequent shutdowns for unclogging or replacement of the drill bit, severely impacting drilling efficiency. While other patented solutions aim to optimize drill bit replaceability, their structures remain complex and do not fundamentally solve the problems of cuttings backflow and efficient cooling.

[0004] Therefore, there is an urgent need for a mining directional drill bit that integrates efficient check flow, optimized cooling, and robust durability. Utility Model Content

[0005] This invention addresses the shortcomings of existing technologies by providing a mine directional drill bit with active backflow prevention for slag, which not only prevents the backflow of coal slag and slime but also improves the cooling effect.

[0006] This utility model is achieved through the following technical solution: a mining directional drill bit with active check valve is provided, including a drill bit body and a cutter head installed at the front end of the drill bit body. The drill bit body is provided with a drilling fluid channel, and an active check valve mechanism is installed in the drilling fluid channel. The active check valve mechanism opens in the direction of drilling fluid flow and closes in the opposite direction of drilling fluid flow.

[0007] This solution achieves on / off control of the drilling fluid channel by installing an active check mechanism inside the drilling fluid channel. This ensures that the drilling fluid channel can only be opened in the direction of the drilling fluid flow during drilling operations, and the drilling fluid channel is closed when drilling operations stop, preventing coal slime and slag from flowing back into the screw motor.

[0008] As an optimization, the active check mechanism includes a first baffle, a check plate, and a second baffle arranged sequentially along the drilling fluid flow direction. Both the first and second baffles are fixedly installed and each has a drilling fluid through-hole. The check plate is adapted to the drilling fluid through-hole on the first baffle, and the check plate is connected to the second baffle via a spring. In this optimized active check mechanism, the spring pushes the check plate against the drilling fluid through-hole on the first baffle to achieve sealing and prevent backflow of coal slag. During normal drilling operations, the drilling fluid pressure overcomes the spring force, causing the check plate to separate from the first baffle, thus opening the active check mechanism.

[0009] As an optimization, the first baffle, check plate, second baffle, and spring are coaxially arranged. The check plate pushes against the first baffle axially, and the area of ​​the check plate is larger than the area of ​​the drilling fluid through hole on the first baffle. This optimized design uses the check plate to block the drilling fluid through hole from one side, has a simple structure, and is easy to install in the drilling fluid channel.

[0010] As an optimization, a guide post extending towards the first baffle is fixed on the second baffle, and the spring is sleeved on the guide post. This optimized solution, by setting the guide post, provides guidance for the extension and contraction of the spring, avoids spring deflection, and thus ensures that the check plate can block the drilling fluid through-hole on the first baffle.

[0011] As an optimization, a guide rod extending axially into the guide post is fixed on the check plate, and a guide hole adapted to the guide rod is provided in the guide post. This optimized solution, by setting the guide rod and the guide hole, allows the guide rod to slide along the guide hole, thereby realizing the movement guidance of the check plate and further ensuring that the check plate is aligned with the drilling fluid through hole on the first baffle.

[0012] As an optimization, both the first and second baffles are fixedly connected to the same support frame. The support frame has retaining rings on both sides along its axial direction, and the distance between the two retaining rings is adapted to the axial length of the support frame. The inner wall of the drilling fluid channel has grooves that respectively adapt to the two retaining rings. This optimized solution improves the overall integrity of the active check mechanism by setting up a support frame, facilitating overall installation and disassembly. The retaining rings limit the position of the support frame, reducing the difficulty of installation and disassembly.

[0013] As an optimization, the rear end of the drill bit body is equipped with a tapered connecting thread adapted to the screw motor. This optimization allows for a direct connection between the drill bit body and the screw motor, making it more convenient to use.

[0014] As an optimization, the drill bit body also has two sets of water passages located in front of and connected to the drilling fluid channel. Each set contains two water passages, each extending to the front end face of the drill bit body. The outlet of each water passage is located between two adjacent sets of cutter heads along the circumferential direction. The axis of one set of water passages is parallel to the axis of the drill bit body, while the axis of the other set forms an angle of 30° to 45° with the axis of the drill bit body. This optimized water passage arrangement avoids both pressure dispersion caused by too many outlets and poor cooling effect caused by too few outlets.

[0015] As an optimization, the intersection of the center line connecting the two water passages in one set and the center line connecting the two water passages in another set is located on the axis of the drill bit body. In this optimized scheme, the two sets of water passages are alternately arranged circumferentially, serving to flush away coal slag and cool the drill bit, respectively, further improving the cooling effect.

[0016] As an optimization, the angle between the plane of the cutting edge of the cutter head and the vertical direction is 10°~12°. This optimization scheme breaks away from the traditional large-angle cutter head design, reduces cutting resistance, and improves drilling efficiency.

[0017] The beneficial effects of this utility model are as follows: by setting an active check mechanism, the flow of drilling fluid during normal operation can be guaranteed, and the backflow of coal slag to the screw motor can be avoided after the operation stops. In addition, there is no need to set an independent check drill rod, which simplifies the drill string assembly structure and reduces the weight of the drilling system head. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of this utility model; Figure 2 This is a side view of the present invention; Figure 3 for Figure 2 Sectional view of AA; As shown in the figure: 1. Drill bit body; 2. Retaining ring; 3. Support frame; 4. Spring; 5. Guide rod; 6. First baffle; 7. Guide post; 8. Cutting head; 9. Drilling fluid through hole on the first baffle; 10. Check plate; 11. Second baffle; 12. Drilling fluid channel; 13. Water inlet; 14. Screw motor; 15. Cutting blade; 16. Tapered connecting thread. Detailed Implementation

[0019] To clearly illustrate the technical features of this solution, the following detailed implementation method will be used to explain the solution.

[0020] like Figure 1The diagram illustrates a mining directional drill bit for actively preventing backflow in slag formation. It includes a drill bit body 1 and several sets of cutter heads 8 mounted on the front end of the drill bit body 1. The angle between the cutting edge plane of each cutter head and the vertical direction is 10° to 12°. This embodiment uses four sets of cutter heads, spaced apart circumferentially. The cutter heads are fixedly connected to the drill bit body via cutter wings 15. The cutter heads utilize ultra-strong PDC composite sheets, and composite strips are fixed to the sides of the cutter wings.

[0021] The drill bit body is provided with a drilling fluid channel 12, and an active check mechanism is installed in the drilling fluid channel 12. The active check mechanism opens in the direction of drilling fluid flow and closes in the opposite direction of drilling fluid flow. The drilling fluid flow direction refers to the direction of drilling fluid flow during drilling operations. In this embodiment, by setting an active check mechanism, the opening and closing of the drilling fluid channel can be controlled, so that the drilling fluid can only flow in the direction of flow during drilling operations, preventing backflow of slag and slurry.

[0022] Specifically, the active check valve mechanism in this embodiment includes a first baffle 6, a check valve 10, and a second baffle 11 arranged sequentially along the drilling fluid working flow direction. Both the first baffle 6 and the second baffle 11 are fixedly installed and each has a drilling fluid through-hole. The first baffle is sealed to the side wall of the drilling fluid channel. The check valve is axially movable. The check valve 10 is adapted to the drilling fluid through-hole 9 on the first baffle, and the check valve 10 is connected to the second baffle 11 via a spring 4. The second baffle has multiple drilling fluid through-holes evenly distributed circumferentially, while the first baffle has one through-hole located at its center. The total area of ​​all drilling fluid through-holes on the second baffle is equal to the area of ​​the drilling fluid through-holes on the first baffle to ensure normal drilling fluid flow.

[0023] In this embodiment, the first baffle 6, the check plate 10, the second baffle 11, and the spring 4 are coaxially arranged. The check plate pushes against the first baffle axially, and the area of ​​the check plate is larger than the area of ​​the drilling fluid through hole on the first baffle. When drilling operations stop, the spring force pushes the check plate against the front side of the first baffle, blocking the drilling fluid through hole 9 on the first baffle, preventing coal slag from flowing back into the screw motor 14, thus ensuring the safety of the screw motor 14.

[0024] To ensure alignment between the check plate and the drilling fluid through-hole 9 on the first baffle and prevent misalignment, a guide post 7 extending toward the first baffle is fixedly mounted on the second baffle, and the spring 4 is sleeved on the guide post 7. A guide rod 5 extending axially into the guide post is fixedly mounted on the check plate, and the guide post has a guide hole adapted to the guide rod 5. The guide rod and the guide post are slidably connected axially.

[0025] This embodiment also includes a support frame 3. The first baffle and the second baffle are both fixedly connected to the same support frame 3, which improves the overall integrity of the active check mechanism. The support frame is provided with retaining rings 2 on both sides of the axial direction. The distance between the two retaining rings is adapted to the axial length of the support frame. The inner wall of the drilling fluid channel is provided with slots that are adapted to the two retaining rings. After the support frame is installed in place, the two retaining rings are respectively locked in the two slots. The two retaining rings are used to limit the support frame and fix the support frame. This reduces the impact of complex connections on the tapered connection thread, enhances the overall reliability, disperses the stress at the connection point, and effectively prevents stress concentration and fracture at the threaded part.

[0026] To facilitate connection with the screw motor 14, this embodiment has a tapered connecting thread 16 adapted to the screw motor 14 at the rear end of the drill bit body, which can be directly connected to the screw motor, thereby eliminating the traditional independent check rod, simplifying the drill bit assembly, and reducing the weight of the drilling system head.

[0027] The drill bit body also has two sets of water passages 13 located in front of and connected to the drilling fluid channel. Each set has two water passages, each extending to the front end face of the drill bit body. The outlet of each water passage is located between two adjacent sets of cutter heads along the circumferential direction. The axis of one set of water passages is parallel to the axis of the drill bit body, while the axis of the other set forms an angle of 30° to 45° with the axis of the drill bit body. The intersection of the center line connecting the two water passages in one set and the center line connecting the two water passages in the other set is located on the axis of the drill bit body. The two sets of water passages form a multi-channel water passage structure, which can efficiently guide the drilling fluid to each high-strength PDC composite plate during drilling, achieving effective cooling and ensuring that the PDC composite plate operates at a suitable temperature, thus extending the service life of the drill bit. It also helps to remove rock cuttings from the bottom of the hole. The two water passages parallel to the axis of the drill bit body serve to flush and cool the slag. The other two inclined water passages cool the cutter wings and side composite plates, thus solving the problem of poor cooling effect caused by pressure dispersion due to too many water outlets, and avoiding the problem of insufficient water outlets that can only serve a flushing function and cannot effectively cool the drill bit.

[0028] During drilling, drilling fluid pressure pushes the check plate 10 open to allow water to flow. When drilling stops, the working pressure disappears, and spring 4 immediately resets the check plate, sealing the slag backflow channel. This fundamentally prevents slag backflow during drilling stoppage, greatly reducing the risk of damage to the screw motor and improving equipment reliability. The arrangement angle (cutting angle) of the ultra-strong PDC composite blades reduces cutting resistance and improves drilling rig efficiency. Simultaneously, it can effectively break hard rock formations of f12 grade and below, achieving higher drilling speeds and better breaking effects.

[0029] The directional drill bit of this embodiment features a high degree of modularity, making key components easy to disassemble and replace, thus reducing the difficulty and cost of later maintenance. When the check valve or drill bit head needs repair or replacement, it can be operated through the disassembly hole using standard parts such as elastic retaining rings, simplifying maintenance and effectively preventing coal slag backflow, improving drilling efficiency, and facilitating maintenance. It also protects the screw motor. Through structural integration, the independent check valve drill rod is eliminated, making the drill string assembly shorter and lighter, facilitating operation in narrow downhole spaces and reducing overall weight. Furthermore, through optimized cooling channels and composite plate design, drilling efficiency, breaking capacity, and drill bit lifespan are improved, while also facilitating maintenance.

[0030] Of course, the above description is not limited to the examples above. Technical features of this utility model not described can be implemented by or using existing technology, and will not be repeated here. The above embodiments and drawings are only used to illustrate the technical solution of this utility model and are not intended to limit this utility model. This utility model has been described in detail with reference to preferred embodiments. Those skilled in the art should understand that any changes, modifications, additions or substitutions made by those skilled in the art within the scope of this utility model do not depart from the spirit of this utility model and should also fall within the protection scope of the claims of this utility model.

Claims

1. A mining directional drill bit for actively preventing backflow of slag, comprising a drill bit body (1) and a cutting head (8) installed at the front end of the drill bit body (1), characterized in that: The drill bit body is provided with a drilling fluid channel (12), and an active check mechanism is installed in the drilling fluid channel (12). The active check mechanism opens in the direction of drilling fluid flow and closes in the opposite direction of drilling fluid flow. The active check mechanism includes a first baffle (6), a check plate (10), and a second baffle (11) arranged sequentially along the working direction of the drilling fluid. The first baffle (6) and the second baffle (11) are both fixedly arranged and each has a drilling fluid through hole. The check plate (10) is adapted to the drilling fluid through hole (9) on the first baffle, and the check plate (10) is connected to the second baffle (11) by a spring (4). The first baffle (6), the check plate (10), the second baffle (11) and the spring (4) are coaxially arranged. The check plate pushes against the first baffle along the axial direction, and the area of ​​the check plate is greater than the area of ​​the drilling fluid through hole on the first baffle. The second baffle is fixedly provided with a guide post (7) extending toward the first baffle, and the spring (4) is sleeved on the guide post (7).

2. The mining directional drill bit for actively preventing backflow of slag as described in claim 1, characterized in that: The check plate is fixed with a guide rod (5) extending axially into the guide post, and the guide post is provided with a guide hole adapted to the guide rod (5).

3. A mining directional drill bit for actively preventing backflow in slag formation according to claim 1, characterized in that: The first baffle and the second baffle are both fixedly connected to the same support frame (3). The support frame is provided with retaining rings (2) on both sides of the axial direction. The distance between the two retaining rings is adapted to the axial length of the support frame. The inner wall of the drilling fluid channel is provided with slots adapted to the two retaining rings respectively.

4. A mining directional drill bit for actively preventing backflow of slag as described in claim 1, characterized in that: The rear end of the drill bit body is provided with a tapered connecting thread adapted to the screw motor (14).

5. A mining directional drill bit for actively preventing backflow of slag as described in claim 1, characterized in that: The drill bit body is also provided with two sets of water passages (13) located in front of the drilling fluid passage and connected to the drilling fluid passage. Each set has two water passages, each water passage extending to the front end face of the drill bit body. The water outlet of each water passage is located between two adjacent sets of cutter heads along the circumferential direction. The axis of one set of water passages is parallel to the axis of the drill bit body, and the axis of the other set of water passages is at an angle of 30°~45° with the axis of the drill bit body.

6. A mining directional drill bit for actively preventing backflow in slag formation according to claim 5, characterized in that: The intersection of the center line connecting the two water passages in one group and the center line connecting the two water passages in another group is located on the axis of the drill bit body.

7. A mining directional drill bit for actively preventing backflow in slag formation according to claim 1, characterized in that: The angle between the plane containing the cutting edge of the blade and the vertical direction is 10°~12°.

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