A drill bit to prevent excavated material from flowing back.

Abstract

This invention discloses a drill bit for preventing backflow of excavated material, belonging to the field of directional drilling technology. It includes a main drill bit with multiple diamond composite plates fixedly mounted on it, and multiple one-way valves I rotatably mounted on it. The main drill bit is fixedly mounted on the drill bit body, and multiple auxiliary drill bits are fixedly mounted on the drill bit body, each with a diamond composite plate fixedly mounted. The drill bit body has an upper cavity, a middle cavity, and a lower cavity. An adjustment assembly is installed on the drill bit body, located in the middle and upper cavities. A valve assembly is installed on the drill bit body, located in the middle and lower cavities. This invention effectively prevents backflow of excavated material from damaging the motor and also effectively solves the problem of cumbersome drill jamming procedures during drill lifting.

Description

Technical Field

[0001] This invention relates to the field of directional drilling technology, and in particular to a drill bit for preventing the backflow of excavated material. Background Technology

[0002] With the development of directional drilling technology, it is now widely used in coal mine excavation, primarily in gas extraction, water exploration and drainage, and coal seam floor grouting reinforcement, greatly improving work efficiency. Downhole directional drilling technology utilizes a screw motor with a bent joint, coupled with a measurement-while-drilling system to achieve precise control of the borehole trajectory, ensuring the drill bit follows a predetermined path. However, with the expansion of the application scope of directional drilling technology, the geological formations in drilling operations are becoming more complex, and the working conditions are becoming increasingly harsh. Due to the gradual increase in drilling depth, the probability of traversing fractured rock strata or soft coal seams is increasing. In particular, in recent years, my country has gradually promoted air directional drilling to soft coal seams. Because the coal seam is soft, after the drill bit is lifted and the flushing medium is cut off, the flushing medium often carries drill cuttings back from the drill bit's water hole to the screw motor. The drill cuttings enter the stator-rotor gap of the screw motor, causing damage to the rubber inside the stator and reducing the life of the screw motor. To solve this problem, the commonly used method is to add a one-way valve between the drill bit and the directional drilling tool. Although this method solves the problem of the flushing medium carrying rock powder backflow, the flushing medium pushes the spring, causing the flushing medium to lose kinetic energy, reducing the screw motor speed, and sacrificing some drilling efficiency. On the other hand, due to the instability of the formation during drilling, coal from the formation inside the borehole wall may enter the borehole, making it difficult to remove the directional drilling tool and measurement system from the borehole. The most common method is to rotate the drilling tool and use flushing medium to flush the stuck drill bit. However, since the flushing medium flows towards the bottom of the hole, after the drill bit gets stuck in the middle section, the flushing medium must fill the entire borehole before the stuck drill bit can be cleaned, resulting in poor flushing effect.

[0003] The existing technology, including utility model patent CN216517892U, provides a backflow-proof sealed coring drill bit, comprising an inner drill bit, an outer drill bit, and an anti-backflow device. The inner and outer drill bits are fixedly connected and both are hollow structures. The outer drill bit has multiple cutting blades evenly distributed around its top circumference. A chip removal channel and a Y-shaped through-pipe are provided between adjacent cutting blades. The anti-backflow device is installed within the through-pipe, and includes steel balls slidably disposed at the intersections of the through-pipes. The diameter of the steel balls is larger than the diameter of the main through-pipe. The advantage is that the steel balls can block the main through-pipe. Under normal use, the main through-pipe can be opened under pressure; during backflow, it can block the main through-pipe, preventing coal slag from flowing back and blocking the coal extraction device and the stepped annular channel inside the drill bit during compressed air coal extraction. However, this method results in the loss of kinetic energy of the flushing medium, and if a stuck drill is encountered during extraction, the handling is relatively troublesome, resulting in low efficiency. Summary of the Invention

[0004] The technical problem to be solved by this invention is that ordinary one-way valves reduce the kinetic energy of the flushing medium; and the operation steps for encountering a stuck drill during drill lifting are too cumbersome.

[0005] To address the above technical problems, the present invention adopts the following technical solution: a drill bit for preventing the backflow of excavated material, comprising a main drill bit, on which multiple diamond composite plates are fixedly installed, and multiple one-way valves I are rotatably installed. The main drill bit is fixedly mounted on the drill bit body, and multiple auxiliary drill bits are fixedly installed on the drill bit body, each auxiliary drill bit having a diamond composite plate fixedly installed. The drill bit body is provided with an upper cavity, a middle cavity, and a lower cavity. An adjustment assembly is installed on the drill bit body, located in the middle and upper cavities of the drill bit body. The adjustment assembly is provided with a sliding drill body, a buffer ring, and a buffer slide rod. Multiple buffer slide rods are slidably connected to the sliding drill body, and the buffer slide rods intermittently engage with the sliding drill body. A valve assembly is installed on the drill bit body, located in the middle and lower parts of the drill bit body. The valve assembly is provided with valve unit I and valve unit II, which are rotatably connected to the drill bit body, respectively, and the connection between the middle and lower cavities is controlled by valve unit I and valve unit II.

[0006] Preferably, the main drill bit is provided with multiple holes for the flow of flushing medium, and the one-way valve I is rotatably installed on these holes. The holes on the main drill bit are connected to the lower cavity of the drill bit body. The end of the drill bit body away from the main drill bit is provided with multiple holes, and the one-way valve II is rotatably installed on the holes.

[0007] Preferably, a set of fixed limiting plates are fixedly installed on the drill bit body, and an adjusting ring and a valve switch are slidably installed on the drill bit body. The adjusting ring is slidably connected to the drill bit body and is located in the lower cavity of the drill bit body. A set of sliding limiting plates are fixedly installed on the adjusting ring. Switch column I is fixedly installed on valve unit I, and switch column II is fixedly installed on valve unit II. Switch column I and switch column II are slidably installed on the valve switch, and spring III is fixedly installed on the valve switch.

[0008] Preferably, multiple adjusting columns II and springs IV are fixedly connected to the adjusting ring plate, the other end of spring IV is fixedly connected to adjusting column I, adjusting column I is slidably connected to adjusting column II, and adjusting column II is slidably connected to the drill bit body.

[0009] Preferably, the sliding drill body is slidably connected to the drill bit body, a spring III is fixedly connected to the sliding drill body, a buffer ring is slidably connected to the drill bit body, the buffer ring is located in the middle cavity of the drill bit body, an adjusting column I is fixedly connected to one end of the buffer ring near the main drill bit, and the inner ring of the buffer ring is provided with multiple stepped ring grooves.

[0010] Preferably, multiple springs I are fixedly installed on the sliding drill body, with the other end of spring I fixedly connected to the drill bit body. Multiple springs II are fixedly connected to the sliding drill body, with the other end of spring II fixedly connected to a buffer slide rod. One end of the buffer slide rod is intermittently engaged with the stepped ring groove on the buffer ring, and the other end of the buffer slide rod is slidably connected to a switch slide rod.

[0011] Preferably, the switch slide is slidably connected to the drill bit body, the switch slide is located in the upper cavity of the drill bit body, and a reverse valve is fixedly connected to the switch slide, the reverse valve being slidably connected to the drill bit body.

[0012] Preferably, the sliding drill body is provided with multiple side drainage ports, and the end of the sliding drill body away from the main drill bit is provided with threads for connecting the drill rod.

[0013] The beneficial effects of the present invention compared with the prior art are: (1) The drill bit for preventing backflow of excavated material described in the present invention achieves double protection by setting valve assembly and reverse valve, effectively preventing backflow of excavated material; (2) The drill bit for preventing backflow of excavated material described in the present invention effectively prevents the loss of kinetic energy of flushing medium by setting one-way valve I and one-way valve II; (3) The drill bit for preventing backflow of excavated material described in the present invention can effectively prevent the drill bit from being damaged by setting buffer ring; (4) The drill bit for preventing backflow of excavated material described in the present invention achieves the function of quick cleaning when encountering stuck drill by setting buffer ring, buffer slide, switch slide and reverse valve. Attached Figure Description

[0014] Figure 1 This is a frontal view of the overall structure of the present invention.

[0015] Figure 2 This is a top view of the overall structure of the present invention.

[0016] Figure 3 This is a schematic diagram of the overall structure of the present invention viewed from below.

[0017] Figure 4 This is a cross-sectional view of the overall structure of the present invention.

[0018] Figure 5 This is a cross-sectional view of the drill bit body.

[0019] Figure 6 This is a schematic diagram of the valve assembly structure.

[0020] Figure 7 This is a schematic diagram of a local structure of the adjustment component.

[0021] Figure 8 This is a cross-sectional view of the drill bit body and the main drill bit.

[0022] Reference numerals: 2-Adjusting assembly; 3-Valve assembly; 101-Main drill bit; 102-Diamond composite plate; 103-Drill bit body; 104-Auxiliary drill bit; 105-One-way valve I; 106-One-way valve II; 201-Sliding drill body; 202-Buffer ring; 203-Side drain port; 204-Spring I; 205-Spring II; 206-Buffer slide rod; 207-Switch slide rod; 208-Reverse valve; 209-Spring III; 301-Valve unit I; 302-Valve unit II; 303-Spring IV; 304-Adjusting column I; 305-Adjusting ring plate; 306-Adjusting column II; 307-Valve switch; 308-Fixed limit plate; 309-Switch column I; 310-Switch column II; 311-Sliding limit plate. Detailed Implementation

[0023] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0024] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual images. They should not be construed as limiting the scope of this patent. To better illustrate the embodiments of the present invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual dimensions of the product. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0025] Example: Figures 1-5 As shown, multiple diamond composite plates 102 are fixedly installed on the main drill bit 101, and multiple one-way valves I 105 are rotatably installed on the main drill bit 101. The main drill bit 101 is fixedly installed on the drill bit body 103, and multiple auxiliary drill bits 104 are fixedly installed on the drill bit body 103. Diamond composite plates 102 are fixedly installed on the auxiliary drill bits 104. The drill bit body 103 is provided with an upper cavity, a middle cavity, and a lower cavity. An adjustment assembly 2 and a valve assembly 3 are installed on the drill bit body 103. Multiple holes are provided on the main drill bit 101 for the flow of flushing medium. One-way valves I 105 are rotatably installed on these holes. The holes on the main drill bit 101 are connected to the lower cavity of the drill bit body 103. Multiple holes are provided at the end of the drill bit body 103 away from the main drill bit 101, and one-way valves II 106 are rotatably installed on the holes.

[0026] like Figures 4-6As shown, a set of fixed limiting plates 308 are fixedly installed on the drill bit body 103. An adjusting ring plate 305 and a valve switch 307 are slidably installed on the drill bit body 103. The adjusting ring plate 305 is slidably connected to the drill bit body 103 and is located in the lower cavity of the drill bit body 103. A set of sliding limiting plates 311 are fixedly installed on the adjusting ring plate 305. A switch column I 309 is fixedly installed on the valve unit I 301. A switch column II 310 is fixedly installed on the valve unit II 302. Switch columns I 309 and II 310 are slidably installed on the valve switch 307. A spring III 209 is fixedly installed on the valve switch 307. Multiple adjusting columns II 306 and springs IV 303 are fixedly connected to the adjusting ring plate 305. The other end of the spring IV 303 is fixedly connected to the adjusting column I 304. The adjusting column I 304 is slidably connected to the adjusting column II 306. The adjusting column II 306 is slidably connected to the drill bit body 103.

[0027] like Figure 5 , Figure 7 , Figure 8 As shown, the sliding drill body 201 is slidably connected to the drill bit body 103. A spring Ⅲ 209 is fixedly connected to the sliding drill body 201. A buffer ring 202 is slidably connected to the drill bit body 103, and is located in the central cavity of the drill bit body 103. An adjusting column Ⅰ 304 is fixedly connected to one end of the buffer ring 202 near the main drill bit 101. Multiple stepped annular grooves are provided on the inner ring of the buffer ring 202. Multiple springs Ⅰ 204 are fixedly installed on the sliding drill body 201. The other end of each spring Ⅰ 204... A plurality of springs II 205 are fixedly connected to the drill bit body 103. The other end of the springs II 205 is fixedly connected to the buffer slide rod 206. One end of the buffer slide rod 206 is intermittently engaged with the stepped ring groove on the buffer ring 202. The other end of the buffer slide rod 206 is slidably connected to a switch slide rod 207. A plurality of side drain ports 203 are provided on the sliding drill body 201. The end of the sliding drill body 201 away from the main drill bit 101 is provided with a thread for connecting the drill rod.

[0028] Working principle: The drill rod is connected to the sliding drill body 201 via a thread. The rotation of the drill rod causes the sliding drill body 201 to drive the drill bit body 103 to rotate, which in turn drives the main drill bit 101 to rotate. In the initial state, since spring IV 303 is always stretched, the buffer ring 202 will press against the buffer slide rod 206. Since the elastic force of spring II 205 is greater than that of spring IV 303, spring II 205 will not be compressed at this time. The adjusting ring 305 will cause the sliding limit plate 311 to press against valve unit I 301 and valve unit II 302. Since there is also a fixed limit plate 308 on the other side of valve unit I 301 and valve unit II 302, valve unit I 301 and valve unit II 302 are limited at this time. The sliding drill body 201 will not be opened; that is, the flushing medium in the sliding drill body 201, or even the flushing medium that flows back after the one-way valve I 105 is damaged, will not open valve unit I 301 or valve unit II 302. Simultaneously, due to the presence of the fixed limiting plate 308 restricting the displacement of valve unit I 301 and valve unit II 302, and because the elastic force of spring III 209 is greater than that of spring IV 303, the bottom end of the sliding drill body 201 will not contact the lower end face of the middle cavity of the drill bit body 103 under the action of spring IV 303. In the initial state, the upper end face of the buffer ring 202 is pre-set at a distance from the upper end face of the middle cavity of the drill bit body 103. When the main drill bit 101 and the diamond composite plate 102 contact the ground, the drill rod will drive the sliding drill body 201 downwards. When the sliding drill body 201 is in motion, spring I 204 is compressed until the bottom end of the sliding drill body 201 contacts the bottom end face of the middle cavity of the drill bit body 103. Meanwhile, spring III 209 presses against valve switch 307, causing valve switch 307 to shift. Therefore, spring III 209 is not compressed at this time. Switch pins I 309 and II 310 slide on valve switch 307, driving valve units I 301 and II 302 to rotate by a preset angle. Because the elastic force of spring III 209 is greater than that of spring IV 303, valve units I 301 and II 302 press against the sliding limit plate 311 and adjusting ring plate 305 during rotation, causing spring IV 303 to stretch again. As the sliding drill body 201... As the buffer slide bar 206 moves downward, the buffer ring 202 will also press down on the buffer slide bar 206 and move downward as well, causing the spring IV 303 to contract slightly. However, in this process, the spring IV 303 is still stretched again. That is, when the sliding drill body 201 rotates and presses down to make the main drill bit 101 and diamond composite plate 102 start drilling, valve unit I 301 and valve unit II 302 will automatically open, so that the flushing medium begins to reach the lower cavity from the middle cavity of the drill bit body 103, and then is discharged through the one-way valve I 105, thereby assisting the work of the main drill bit 101 and diamond composite plate 102. The sliding buffer ring 202 is set to reduce the stretching length of the spring IV 303 and prevent the spring IV 303 from being overstretched.

[0029] After drilling is completed, the sliding drill body 201 is lifted by the drill rod. At this time, spring I 204 returns to its original position, valve switch 307 is reset by spring III 209, and sliding limit plate 311 is reset by spring IV 303. During the upward movement of the sliding drill body 201, buffer ring 202 is driven upward by buffer slide rod 206. This action will stretch spring IV 303, but the reset of adjusting ring plate 305 will cause spring IV 303 to retract. In general, spring IV 303 retracts and resets to its original state. The function of adjusting column II 306 in this process is to block and prevent the lower cavity from communicating with the middle cavity. This ensures that the flushing medium between the middle and lower cavities can only flow through valve unit I 301 and valve unit II 302. When valve unit I 301 and valve unit II 302 reset, the channel is closed again, preventing the flushing medium from flowing here. This prevents the backflow of flushing medium containing excavated material in the event of damage to check valve I 105, thus providing a double protection.

[0030] After all parts have returned to their initial state, the drill rod continues to drive the sliding drill body 201 upward. In the initial state, the side drain port 203 is located between the upper and middle cavities of the drill bit body 103, meaning that the flushing medium will not flow into the upper and middle cavities. When a blockage is encountered during the upward movement, the drill bit body 103 and the auxiliary drill bit 104 cannot move. The sliding drill body 201 drives the buffer slide rod 206 to continue upward. At this time, springs III 209, I 204, and IV 303 all begin to be stretched. The buffer slide rod 206 drives the buffer ring 202 to slide upward. When the buffer ring 202 slides to the upper end face of the middle cavity of the drill bit body 103, the sliding drill body 201 also slides the same distance relative to the drill bit body 103. At this time, the side drain port 203 on the sliding drill body 201 is connected to the upper cavity of the drill bit body 103, and the flushing medium begins to fill the upper cavity. Then the sliding drill body 201 continues to move upward, the drill bit body 103 stops moving, and the spring II 205 begins to be compressed. After the spring II 205 is compressed, the buffer slide rod 206 drives the switch slide rod 207 to slide. The switch slide rod 207 causes the reverse valve 208 to open. At this time, the flushing medium discharged from the side drain port 203 is discharged through the one-way valve II 106, which works in conjunction with the auxiliary drill bit 104 and the diamond composite plate 102. In order to prevent damage to the drill bit body 103 and the auxiliary drill bit 104, multiple stepped annular grooves are provided on the buffer ring 202 for buffering. After the diamond composite plate 102 and auxiliary drill bit 104 have cleared the blockage, the auxiliary drill bit 104 and drill bit body 103 can move. At this time, springs I 204, spring III 209, spring IV 303, and spring II 205 all begin to reset. The function of springs I 204 and spring III 209 is to return the relative position of the sliding drill body 201 and the drill bit body 103 to the initial state. Since the buffer slide rod 206 may slide on the buffer ring 202 at this time, the tension of spring IV 303 will be weakened after resetting, but it can still meet the working purpose of the adjusting ring plate 305. After spring II 205 resets, the reverse valve 208 closes the channel, and the side drain port 203 of the sliding drill body 201 resets. The flushing medium will no longer be discharged into the upper cavity of the drill bit body 103, which also serves as a double protection, preventing external flushing medium from entering through the one-way valve II 106. When used again, the sliding drill body 201 will be pressed down until the bottom end of the sliding drill body 201 contacts the bottom end face of the middle cavity of the drill bit body 103. During this process, the misalignment caused by the buffer slide rod 206 sliding on the buffer ring 202 to reduce the impact force of the auxiliary drill bit 104 will be restored at this time without manual adjustment. The setting of one-way valve I 105 and one-way valve II 106 ensures that the flushing medium can only flow in one direction, and the flushing medium will not lose too much kinetic energy when flowing through one-way valve I 105 and one-way valve II 106.

[0031] This invention is not limited to the specific embodiments described above. Any modifications made by those skilled in the art based on the above concept without creative effort are within the protection scope of this invention.

Claims

1. A drill bit for preventing backflow of excavated material, comprising a main drill bit (101), wherein a plurality of diamond composite plates (102) are fixedly mounted on the main drill bit (101), a plurality of one-way valves I (105) are rotatably mounted on the main drill bit (101), and the main drill bit (101) is fixedly mounted on a drill bit body (103), characterized in that: The drill bit body (103) is fixedly installed with a plurality of auxiliary drill bits (104), the auxiliary drill bits (104) are fixedly installed with diamond composite pieces (102), the drill bit body (103) is provided with an upper cavity, a middle cavity and a lower cavity, the drill bit body (103) is installed with an adjusting assembly (2), the adjusting assembly (2) is located in the middle cavity and the upper cavity of the drill bit body (103), the adjusting assembly (2) comprises a sliding drill body (201), a buffer ring (202) and a buffer sliding rod (206), a plurality of buffer sliding rods (206) are slidably connected to the sliding drill body (201), and the buffer sliding rods (206) are intermittently matched with the sliding drill body (201); the drill bit body (103) is installed with a valve assembly (3), the valve assembly (3) is located in the middle cavity and the lower cavity of the drill bit body (103), the valve assembly (3) is provided with a valve unit I (301) and a valve unit II (302), the valve unit I (301) and the valve unit II (302) are rotatably connected with the drill bit body (103) respectively, and whether the middle cavity and the lower cavity are communicated is controlled through the valve unit I (301) and the valve unit II (302); A group of fixed limiting pieces (308) are fixedly installed on the drill bit body (103), an adjusting ring piece (305) and a valve switch (307) are slidably installed on the drill bit body (103), the adjusting ring piece (305) is slidably connected with the drill bit body (103), the adjusting ring piece (305) is located in the lower cavity of the drill bit body (103), a group of sliding limiting pieces (311) are fixedly installed on the adjusting ring piece (305), a switch column I (309) is fixedly installed on the valve unit I (301), a switch column II (310) is fixedly installed on the valve unit II (302), the switch column I (309) and the switch column II (310) are slidably installed on the valve switch (307) respectively, and a spring III (209) is fixedly installed on the valve switch (307); A plurality of adjusting columns II (306) and a spring IV (303) are fixedly connected to the adjusting ring piece (305), the other end of the spring IV (303) is fixedly connected with an adjusting column I (304), the adjusting column I (304) is slidably connected with the adjusting column II (306), and the adjusting column II (306) is slidably connected with the drill bit body (103); The sliding drill body (201) is slidably connected with the drill bit body (103), the spring III (209) is fixedly connected to the sliding drill body (201), the buffer ring (202) is slidably connected with the drill bit body (103), the buffer ring (202) is located in the middle cavity of the drill bit body (103), one end of the buffer ring (202) close to the main drill bit (101) is fixedly connected with the adjusting column I (304), and a plurality of stepped ring grooves are arranged in the inner ring of the buffer ring (202). The sliding drill body (201) is fixedly installed with a plurality of spring I (204), the other end of the spring I (204) is fixedly connected on the drill bit body (103), the sliding drill body (201) is fixedly connected with a plurality of spring II (205), the other end of the spring II (205) is fixedly connected with the buffer slide rod (206), one end of the buffer slide rod (206) is intermittently matched with the stepped ring groove on the buffer ring (202), the other end of the buffer slide rod (206) is slidably connected with the switch slide rod (207); The switch slide rod (207) is slidably connected on the drill bit body (103), the switch slide rod (207) is located in the upper cavity of the drill bit body (103), the switch slide rod (207) is fixedly connected with the reverse valve (208), the reverse valve (208) is slidably connected with the drill bit body (103).

2. A drill bit for preventing backflow of excavated material according to claim 1, wherein: The main drill bit (101) is provided with a plurality of holes for the flow of flushing medium, the one-way valve I (105) is rotatably installed on the holes, the holes on the main drill bit (101) are communicated with the lower cavity of the drill bit body (103), the end of the drill bit body (103) away from the main drill bit (101) is provided with a plurality of holes, and the one-way valve II (106) is rotatably installed on the holes.

3. The drill bit of claim 1, wherein: The sliding drill body (201) is provided with a plurality of side liquid discharge ports (203), and the end of the sliding drill body (201) away from the main drill bit (101) is provided with a thread for connecting a drill rod.

Images