Drill bit for preventing rock slag from blocking blast hole

Abstract

The utility model discloses a drill bit for preventing rock slag from blocking a blast hole, which relates to the technical field of drilling of down-the-hole drills and comprises a water injection device inflow pipe, a drill bit body is arranged at the bottom end of the water injection device inflow pipe, a spiral groove is formed in the outer surface of the drill bit body, and a water storage tank is formed in the center of the top end of the drill bit body. A plurality of water outlet holes are formed in the position, penetrating through the water storage tank, of the surface of the spiral groove, and the water outlet holes are used for injecting water to soften rock slag when the rock slag is too hard. Through the water baffle and the pressing head, water cannot be injected into the rock slag when the rock slag encounters softer rock slag, so that argillization is avoided, and smooth slag discharging is kept. And after hard rock slag is encountered, water is automatically injected into the rock slag, so that the effect of softening the rock slag is achieved, and the drilling resistance is reduced.

Description

Technical Field

[0001] This utility model relates to the field of down-the-hole drilling technology, and in particular to a drill bit for preventing rock debris from clogging blast holes. Background Technology

[0002] Down-the-hole (DH) drilling is one of the core technologies in modern rock drilling, widely used in mining, tunnel construction, foundation engineering, and geological exploration. DH rigs use an independent impactor submerged at the bottom of the hole to directly drive the drill bit. The drill bit breaks the rock under the combined action of impact force and rotational shear force, avoiding energy loss during drill pipe transmission. Its origins can be traced back to the limitations of traditional rock drilling equipment; however, DH rigs, through innovative design, have significantly improved drilling efficiency and adaptability, becoming the mainstream equipment for drilling medium-hard and harder rocks.

[0003] In existing down-the-hole drilling processes, excessively dry cuttings can clump together and clog the borehole, while continuous water injection can lead to excessively thin rock formations. When the rock absorbs too much water, it becomes loose and less compact, significantly reducing its cohesion and causing an imbalance in formation stress. This state can trigger borehole collapse or rock slippage, directly affecting drilling stability. When cuttings clump together and clog the borehole, the drill bit encounters greater resistance as it advances, requiring more energy to overcome this resistance and resulting in a significant decrease in drilling speed.

[0004] To address the issue of excessively dry rock cuttings clumping and clogging boreholes, while continuous water injection could lead to overly thin rock formations, a spring is installed inside the drill bit. The spring's elasticity can be preset based on the rock formation characteristics. When the rock cuttings are too dry, changes in internal drill bit pressure or rock cutting resistance trigger spring deformation, moving the blocking plate away from the water outlet and automatically increasing the water injection rate. Conversely, when the rock cuttings have suitable moisture content, the spring resets, the blocking plate closes, or the water output decreases, preventing the rock formations from becoming too thin. This automatic spring adjustment allows for precise control of the water injection rate, reducing downtime for adjustments and improving drilling efficiency.

[0005] However, in the current use of drill bits, the drill bit may break when it encounters hard rock cuttings at the bottom during drilling. After the drill bit breaks, the drilling operation must be stopped immediately for replacement, resulting in interruption of drilling operations. The impact force generated when the drill bit breaks may be transmitted to the drill pipe, causing the drill pipe to bend, break, or loosen at the connection points. Utility Model Content

[0006] The purpose of this invention is to address the shortcomings of existing technologies by proposing a drill bit for preventing rock debris from clogging blast holes. This invention solves the problem that excessively dry rock debris will clump together and block the blast holes, while continuous water injection may lead to excessively thin rock layers.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A drill bit for preventing rock cuttings from clogging blast holes includes a water injection device inlet pipe. A drill bit body is located at the bottom end of the inlet pipe. The outer surface of the drill bit body has spiral grooves, and a water storage tank is located at the center of the top of the drill bit body. Several water outlet holes are formed on the surface of the spiral grooves extending into the water storage tank. These outlet holes are used to inject water to soften the rock cuttings when they are too hard. Water is injected into the water storage tank through the inlet pipe and discharged through the outlet holes, thereby controlling the degree of rock cutting softening.

[0009] As a further improvement of this utility model, four fixing strips are evenly fixedly connected to the inner wall of the top of the water storage tank, and a spring groove is opened inside the drill bit body at the bottom end of the water storage tank. A through-hole is opened at the center of the bottom end of the drill bit body. The fixing strips can restrict the insertion rod inside the water storage tank.

[0010] As a further improvement of this utility model, an insertion rod is provided at the center of the water storage tank. Several connecting rods are evenly and fixedly connected to the outer surface of the insertion rod along a spiral groove. A baffle plate is fixedly connected to the end of each connecting rod away from the insertion rod. The positions of the baffle plates correspond one-to-one with the positions of the water outlets. This correspondence between the water outlets and the baffle plates ensures that all water outlets are sealed, preventing water injection into the rock debris when its softness is moderate.

[0011] As a further improvement of this utility model, four sliding grooves are evenly formed on the outer surface of the top end of the insertion rod. The four fixing strips are slidably connected inside the four sliding grooves. A stop rubber plate is fixedly connected to the bottom end of the insertion rod, and the stop rubber plate is fitted against the bottom end of the water storage tank. A connecting block is fixedly connected to the bottom end of the stop rubber plate, and the connecting block is disposed inside the spring groove. The sliding connection between the fixing strips and the sliding grooves allows the insertion rod to move horizontally within the water storage tank.

[0012] As a further improvement of this utility model, a pressing head is fixedly connected to the bottom end of the connecting block. The pressing head is disposed inside the through opening. A control spring is fixedly connected to the bottom end of the abutting rubber plate. The bottom end of the control spring is fixedly connected to the bottom surface of the spring groove. The control spring is disposed inside the spring groove, and the elastic coefficient of the control spring is the reaction force given by the rock debris. The connection between the control spring and the abutting rubber plate and the spring groove will ensure that when the rock debris is too hard, all water baffles will be moved away from the water outlet.

[0013] Compared with the prior art, the advantages of this utility model are as follows:

[0014] 1. The system utilizes a water baffle and a pressing head to prevent water injection into softer rock cuttings, thus avoiding mud formation and ensuring smooth cuttings removal. Conversely, it automatically injects water into harder rock cuttings to soften them, thereby reducing drilling resistance.

[0015] 2. By controlling the spring, the system can automatically stop the continued flow of water after softening harder rock cuttings to a suitable degree. Through intelligent water control, drilling operations can achieve multiple goals, including efficient resource utilization, cost optimization, and safety and environmental protection, providing sustainable technical support for resource development. Attached Figure Description

[0016] Figure 1 This is a three-dimensional structural diagram of the present invention.

[0017] Figure 2 This utility model Figure 1 A cross-sectional three-dimensional structural diagram of the drill bit body.

[0018] Figure 3 This is a cross-sectional three-dimensional structural diagram of the drill bit body in this utility model.

[0019] Figure 4 This is a three-dimensional structural diagram of the insertion rod, connecting rod, and water baffle in this utility model.

[0020] Figure 5 This utility model Figure 3 A magnified three-dimensional structural diagram at point A in the middle.

[0021] Figure 6 This utility model Figure 3 A magnified three-dimensional structural diagram at point B.

[0022] Figure 7 This utility model Figure 4 A magnified three-dimensional structural diagram at point C.

[0023] Figure 8 This utility model Figure 4 Enlarged 3D structural diagram at point D

[0024] In the diagram: 100, water inlet pipe; 201, drill bit body; 202, spiral groove; 203, water outlet; 204, water storage tank; 205, fixing strip; 206, spring groove; 207, through-hole; 301, insertion rod; 302, connecting rod; 303, water baffle; 304, sliding groove; 305, abutting rubber plate; 306, connecting block; 307, pressing head; 308, control spring. Detailed Implementation

[0025] To make the above-mentioned objectives, features, and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a full understanding of this utility model. However, this utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this utility model. Therefore, this utility model is not limited to the specific embodiments disclosed below.

[0026] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly attached to the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0027] See attached document Figure 1 - Appendix Figure 8 A drill bit for preventing rock debris from clogging blast holes includes a water injection device inlet pipe 100, a drill bit body 201, a water outlet 203, a fixing strip 205, an insertion rod 301, a water baffle 303, a pressing head 307, and a control spring 308.

[0028] In use, this invention first drives the drill bit body 201 to drill, and then injects water into the water storage tank 204 through the water injection device inflow pipe 100. When the pressing head 307 at the bottom of the drill bit body 201 encounters rock cuttings, if the rock cuttings are soft enough not to affect the drilling of the drill bit body 201, the drill bit body 201 rotates all its internal components and the pressing head 307 to drill a hole in the rock strata. At this time, the elastic coefficient of the control spring 308 is greater than the reaction force of the rock cuttings, so that the control spring 308 located at the bottom of the abutment rubber plate 305 will not undergo elastic deformation. Therefore, the drill bit body 201 will not inject water into the rock cuttings when it encounters softer rock cuttings. In drilling operations, choosing not to inject water when the drill bit body 201 encounters softer rock cuttings can avoid the rock cuttings becoming muddy, keep the cuttings discharge channel unobstructed, reduce downtime for cleaning, and increase drilling speed. Moreover, water injection may cause soft rock fragments to disintegrate and become muddy, damaging the original structure of the core and affecting subsequent analysis. Dry rock fragments are easier to classify through methods such as sieving and particle size analysis, which facilitates the study of stratigraphic lithological changes.

[0029] When the pressing head 307 at the bottom of the drill bit body 201 encounters rock cuttings, if the rock cuttings are too hard and affect the drilling of the drill bit body 201, the elastic coefficient of the control spring 308 is less than the reaction force of the rock cuttings. This causes the control spring 308 located at the bottom of the abutment rubber plate 305 to undergo upward elastic deformation. This upward elastic deformation will cause the connecting block 306 and the abutment rubber plate 305 to move upward. Since the insertion rod 301 is fixed to the top of the abutment rubber plate 305, and several water baffles 303 are fixedly connected to the outside of the insertion rod 301 through the connecting rod 302, the water baffles 303 are initially aligned with the water outlet 203, thus preventing leakage from the water outlet 203. When the water baffles 303 move upward under the action of the insertion rod 301, they will no longer block the water outlet 203, allowing water inside the water storage tank 204 to flow from the water outlet 203 into the rock cuttings. This allows for the automatic injection of water into hard rock fragments upon encountering them, softening them. Hard rock fragments are highly brittle and brittle; after water injection, the water seeps into micro-cracks in the rock strata, creating a water wedge effect that reduces the rock's compressive strength and decreases the cutting resistance of the drill bit body 201. Furthermore, the reduced friction between hard rock fragment particles after contact with water makes them easier to discharge through the spiral groove 202, reducing the risk of stuck drill bits due to rock fragment accumulation.

[0030] After the harder rock cuttings have been softened by water injection, the reaction force of the rock cuttings on the control spring 308 will decrease as the drill bit body 201 drives the drill downwards. When the reaction force of the rock cuttings is less than the elastic coefficient of the control spring 308, the control spring 308 will rebound, thus automatically stopping the continued flow of water after the rock cuttings have been softened to a suitable degree. Rock cuttings softened to a suitable degree are easy to cut and do not accumulate easily, reducing drill bit wear and downtime for cleaning. Moreover, excessive softening can lead to borehole collapse, stuck drill bits, and other accidents that may cause personal injury or equipment damage; intelligent water control can significantly reduce such risks.

[0031] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A drill bit for preventing rock debris from clogging blast holes, comprising a water injection device inlet pipe (100), characterized in that, The bottom end of the water injection device inlet pipe (100) is provided with a drill bit body (201). The outer surface of the drill bit body (201) is provided with a spiral groove (202). The center of the top end of the drill bit body (201) is provided with a water storage tank (204). The surface of the spiral groove (202) extends through the water storage tank (204) and is provided with a number of water outlet holes (203). The water outlet holes (203) are used to inject water to soften the rock debris when it is too hard.

2. The drill bit for preventing rock debris from clogging blast holes according to claim 1, characterized in that, Four fixing strips (205) are evenly fixedly connected to the inner wall of the top of the water storage tank (204). A spring groove (206) is opened inside the drill bit body (201) at the bottom of the water storage tank (204). A through hole (207) is opened through the center of the bottom of the drill bit body (201).

3. A drill bit for preventing rock debris from clogging blast holes according to claim 2, characterized in that, An insertion rod (301) is provided at the center of the water storage tank (204). Several connecting rods (302) are evenly and fixedly connected to the outer surface of the insertion rod (301) along the spiral groove (202). A baffle plate (303) is fixedly connected to the end of the connecting rod (302) away from the insertion rod (301). The positions of the several baffle plates (303) correspond one-to-one with the positions of the several water outlets (203).

4. A drill bit for preventing rock debris from clogging blast holes according to claim 3, characterized in that, The top outer surface of the insertion rod (301) is evenly provided with four sliding grooves (304), and the four fixing strips (205) are slidably connected to the inside of the four sliding grooves (304). The bottom end of the insertion rod (301) is fixedly connected to a stop rubber plate (305), which is attached to the bottom end of the water storage tank (204). The bottom end of the stop rubber plate (305) is fixedly connected to a connecting block (306), which is located inside the spring groove (206).

5. A drill bit for preventing rock debris from clogging blast holes according to claim 4, characterized in that, The bottom end of the connecting block (306) is fixedly connected to a pressing head (307), which is located inside the through opening (207). The bottom end of the abutting rubber plate (305) is fixedly connected to a control spring (308), which is fixedly connected to the bottom surface of the spring groove (206). The control spring (308) is located inside the spring groove (206), and the elastic coefficient of the control spring (308) is the reaction force given by the rock slag.

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