A rock drill bit and a drill rig for drilling a cast-in-place pile in a deep silt stratum

Abstract

This utility model discloses a rock drill bit for drilling cast-in-place piles in deep silt strata, belonging to the field of drill bit technology, and solving the problem of inconvenient disassembly and maintenance of existing drill bits. It includes a first outer ring scraper, a second outer ring scraper, and a cutting drill bit. The first and second outer ring scrapers have the same structure, both including a circular ring and multiple scraper blades. The circular ring is detachably installed on the periphery of the drill bit's central rod. The multiple scraper blades are divided into upper and lower layers, with each layer of blades evenly fixed to the outer wall of the circular ring. The cutting drill bit includes multiple cutter discs, each with multiple drill teeth fixed to its outer wall. One end of each cutter disc is detachably connected to the lower part of the drill bit's central rod, and the other end extends obliquely to and is detachably connected to the inner wall of the second outer scraper's circular ring. This utility model's rock drill bit allows for convenient disassembly and maintenance, making construction more convenient. This utility model also discloses a drilling machine for drilling cast-in-place piles in deep silt strata, which can effectively improve construction efficiency.

Description

Technical Field

[0001] This utility model relates to the field of drilling technology, and more specifically, it relates to a rock drill bit and drilling machine for drilling cast-in-place piles in deep silt strata. Background Technology

[0002] The construction of cast-in-place piles in deep silt formations presents significant technical challenges. Firstly, the high sensitivity and low structural strength of silt result in extremely poor borehole stability; disturbance of the drill bit easily leads to necking or borehole collapse, directly affecting the quality of the hole. The drilling method for cast-in-place piles in deep silt formations involves using a rotary drill bit in conjunction with wall-forming mud, transmitting torque and pressure through the drill rod system to achieve drilling. Therefore, the drill bit is a crucial piece of equipment during construction. In practice, different materials or structures of drill bits are typically used for cutting and drilling in different formations to reduce the risk of drill bit damage and improve construction efficiency.

[0003] Existing drill bits for drilling cast-in-place piles, such as those with authorization announcement numbers: CN 212130403 U, CN

[0004] The drill bits disclosed in patents 208870534U and CN 214576767 U are typically conical in shape with a pointed bottom and a circular top. They utilize multiple teeth on the outer wall of the conical drill bit for rotary cutting, in conjunction with the axial feed of the drilling rig, to achieve drilling of cast-in-place piles in deep silty strata. In most of these existing drill bits, the drill teeth are welded and fixed within a conical frame or conical cylinder. In actual use, the drill bit is a wear component, especially when drilling through rock strata, where the risk of breakage is even greater. Furthermore, the welded connection method makes disassembly and maintenance difficult.

[0005] Therefore, it is necessary to design a rock drill bit and drilling machine for drilling deep silt piles to solve the aforementioned technical problems. Utility Model Content

[0006] The technical problem to be solved by this utility model is to address the above-mentioned shortcomings of the existing technology. One of its objectives is to provide a rock drill bit for drilling deep silt strata cast-in-place piles, which can be easily disassembled and maintained, making construction more convenient.

[0007] The second objective is to provide a drilling machine for drilling cast-in-place piles in deep silt formations, thereby improving construction efficiency.

[0008] The technical solution of this utility model is as follows: A rock drill bit for drilling cast-in-place piles in deep silt strata includes a first outer ring scraper, a second outer ring scraper, and a cutting drill bit. The cutting drill bit, the second outer ring scraper, and the first outer ring scraper are mounted on the drill bit shaft from bottom to top, and the first and second outer ring scrapers are spaced apart. The cutting drill bit and the second outer ring scraper are detachably connected. The first and second outer ring scrapers have the same structure, each including a ring and multiple scraper blades, and the ring is detachable. Installed on the periphery of the drill bit rod, the multiple scrapers are divided into upper and lower layers. Each layer of scrapers is evenly fixed on the outer wall of the ring. The diameter of the ring corresponding to the second outer ring scraper is smaller than the diameter of the ring corresponding to the first outer ring scraper. The bottom of the drill bit rod is a pointed structure. The cutting drill bit includes multiple cutter discs. Each cutter disc has multiple drill teeth fixed on its outer wall. One end of each cutter disc is detachably connected to the lower part of the drill bit rod, and the other end extends obliquely to the inner wall of the ring of the second outer ring scraper and is detachably connected to it.

[0009] As a further improvement, the outer wall of the ring and the outer wall of the scraper are both inclined structures with a larger upper surface and a smaller lower surface.

[0010] Furthermore, a sleeve is provided inside the ring, and the sleeve is fixedly connected to the ring by multiple connecting rods. The sleeve is slidably sleeved on the drill bit rod, and a locking structure is provided between the sleeve corresponding to the second outer ring scraper and the drill bit rod. A support structure is provided between each connecting rod corresponding to the first outer ring scraper and the second outer ring scraper.

[0011] Furthermore, the support structure includes a support rod, an upper support nut, and a lower support nut. One end of the support rod is fixed to the top of the connecting rod corresponding to the second outer ring scraper, and the other end slides through the connecting rod corresponding to the first outer ring scraper. The upper support nut and the lower support nut are respectively threaded onto the support rods on the upper and lower sides of the connecting rod corresponding to the first outer ring scraper, and both the upper support nut and the lower support nut are in contact with the surface of the connecting rod corresponding to the first outer ring scraper.

[0012] Furthermore, the locking structure includes two sets of locking bolts and locking nuts, which are arranged vertically and vertically, and the locking bolts pass through the sleeve and the drill bit rod and are threadedly connected to the locking nuts.

[0013] Furthermore, the inner wall of the sleeve is circular, and correspondingly, the outer wall of the drill bit rod is circular.

[0014] Furthermore, the lower part of the drill bit rod is provided with multiple axially extending grooves to its bottom. One end of the cutter head is inserted into the groove and fixed in the groove by countersunk screws. The other end of the cutter head is in contact with the inner wall of the ring corresponding to the second outer ring scraper and fixed in the inner wall of the ring corresponding to the second outer ring scraper by countersunk screws.

[0015] Furthermore, the top of the upper scraper protrudes from the top of the ring, and the bottom of the lower scraper protrudes from the bottom of the ring.

[0016] Furthermore, the drill teeth are made of high-manganese alloy.

[0017] The second technical solution of this utility model is as follows: a drilling machine for drilling cast-in-place piles in deep silt strata, including the rock drill bit mentioned above.

[0018] Beneficial effects

[0019] Compared with the prior art, this utility model has the following advantages:

[0020] 1. The rock drill bit of this utility model has a first outer ring scraper, a second outer ring scraper, and a cutting drill bit that can all be detachably installed on the drill bit rod. The three are independent installation structures that can be detached from each other. In actual application, if any one of the tools is damaged, it can be disassembled and maintained separately, which can facilitate disassembly and maintenance, make construction more convenient, and effectively reduce maintenance costs.

[0021] 2. The rock drilling bit of this utility model adopts a double-ring structure with a cutting drill bit and two outer ring scrapers, which increases the stability of the drill bit during the drilling process, effectively reduces hole collapse and deviation, and ensures construction quality. After the cutting drill bit drills out of the hole, the outer ring scrapers can trim and compact the hole wall, which can realize drilling and hole trimming and compaction at the same time, improve drilling quality, and is particularly suitable for drilling in rock formations. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the main structure of this utility model;

[0023] Figure 2 This is a top view of the structure of this utility model;

[0024] Figure 3 This is a schematic diagram of the front cross-sectional structure of this utility model.

[0025] The components are: 1. First outer ring scraper; 2. Second outer ring scraper; 3. Cutting drill bit; 4. Drill bit rod; 5. Ring; 6. Scraper; 7. Sleeve; 8. Connecting rod; 9. Support rod; 10. Upper support nut; 11. Lower support nut; 12. Locking bolt; 13. Locking nut; 14. Sliding groove; 15. Countersunk screw; 301. Cutter head; 302. Drill teeth. Detailed Implementation

[0026] The present invention will be further described below with reference to specific embodiments shown in the accompanying drawings.

[0027] See Figure 1-3 This utility model discloses a rock drilling bit for drilling deep silt strata for cast-in-place piles, specifically designed for cutting and drilling deep silt strata. It includes a first outer ring scraper 1, a second outer ring scraper 2, and a cutting drill bit 3. The cutting drill bit 3, the second outer ring scraper 2, and the first outer ring scraper 1 are mounted on the drill bit shaft 4 from bottom to top. The cutting drill bit 3 serves as the main cutting tool, while the first outer ring scraper 1 and the second outer ring scraper 2 are tools used to trim and compact the hole wall. The first outer ring scraper 1 and the second outer ring scraper 2 are spaced apart to facilitate the removal of debris after cutting by the cutting drill bit 3. The cutting drill bit 3 and the second outer ring scraper 2 are detachably connected for easy disassembly and maintenance. The first outer ring scraper 1 and the second outer ring scraper 2 have the same structure, both including a circular ring 5 and multiple scraper blades 6. The circular ring 5 is detachably mounted on the periphery of the drill bit shaft 4, and the multiple scraper blades 6 are divided into upper and lower layers, with each layer of scraper blades 6 evenly fixed to the circular ring 5. The outer wall of the drill bit 3 is used to scrape and trim the hole wall multiple times. The diameter of the ring 5 corresponding to the second outer ring scraper 2 is smaller than the diameter of the ring 5 corresponding to the first outer ring scraper 1, ensuring that the first outer ring scraper 1 can contact the hole wall. The bottom of the drill rod 4 is a pointed structure, which facilitates drilling into hard rock strata. The cutting drill bit 3 includes multiple cutter discs 301. Each cutter disc 301 has multiple drill teeth 302 fixed on its outer wall. The drill teeth 302 are tapered cutting teeth with a front angle controlled in the range of 25°-30° and a tooth height of 80-100mm, which ensures the cutting performance of the cutting drill bit 3. One end of each cutter disc 301 is detachably connected to the lower part of the drill rod 4, and the other end extends obliquely to the inner wall of the ring 5 of the second outer ring scraper 2 and is detachably connected to it, which facilitates the individual disassembly and maintenance of the cutting drill bit 3.

[0028] The rock drill bit of this utility model has a first outer ring scraper 1, a second outer ring scraper 2, and a cutting drill bit 3, all of which are detachably mounted on the drill bit rod 4. The three are independently detachable installation structures. In actual application, if any one of the tools is damaged, it can be disassembled and maintained separately, which facilitates disassembly and maintenance, makes construction more convenient, and effectively reduces maintenance costs.

[0029] Meanwhile, its double-ring structure, consisting of a cutting drill bit and two outer ring scrapers, increases the stability of the drill bit during drilling, effectively reducing hole collapse and deviation, and ensuring construction quality. Furthermore, after the cutting drill bit exits the borehole, the outer ring scrapers can trim and compact the borehole wall, enabling simultaneous drilling and borehole trimming and compaction, thus improving drilling quality. This is particularly suitable for drilling in rock formations.

[0030] Preferably, the outer wall of the ring 5 and the outer wall of the scraper 6 are both inclined structures with a larger upper surface and a smaller lower surface, which facilitates the axial feeding of the outer ring scraper.

[0031] Preferably, a sleeve 7 is provided inside the ring 5. The sleeve 7 is fixedly connected to the ring 5 by multiple connecting rods 8 to form a hollow frame structure, which facilitates the discharge of debris. The sleeve 7 is slidably sleeved on the drill bit rod 4, and a locking structure is provided between the sleeve 7 corresponding to the second outer ring scraper 2 and the drill bit rod 4 to prevent it from rotating relative to the drill bit rod 4. A support structure is provided between each connecting rod 8 corresponding to the first outer ring scraper 1 and the second outer ring scraper 2, which can realize the fixed installation of the outer ring scraper 2 and facilitate disassembly and maintenance. Specifically, the support structure includes a support rod 9, an upper support nut 10, and a lower support nut 11. One end of the support rod 9 is fixed to the top of the connecting rod 8 corresponding to the second outer ring scraper 2, and the other end slides through the connecting rod 8 corresponding to the first outer ring scraper 1. The upper support nut 10 and the lower support nut 11 are respectively threaded onto the support rod 9 on the upper and lower sides of the connecting rod 8 corresponding to the first outer ring scraper 1, and both the upper support nut 10 and the lower support nut 11 are attached to the surface of the connecting rod 8 corresponding to the first outer ring scraper 1, so as to fix the two outer ring scrapers at intervals on the drill bit rod 4, and at the same time, the height of the first outer ring scraper 1 can be adjusted.

[0032] In this embodiment, the first outer ring scraper 1 of the rock drill bit is slidably mounted on the drill bit rod 4 and supported and fixed by a support structure. The position of the first outer ring scraper 1 can be adjusted by loosening the upper support nut 10 and the lower support nut 11 as needed to ensure the stability of the drill bit during drilling.

[0033] Preferably, the locking structure includes two sets of locking bolts 12 and locking nuts 13, which are arranged vertically and vertically. This ensures that the force between the ring 5 corresponding to the second outer ring scraper 2 and the drill bit rod 4 is more evenly distributed. The locking bolts 12 pass through the sleeve 7 and the drill bit rod 4 and are threadedly connected to the locking nuts 13, thus fixing the second outer ring scraper 2 in place. Since the first outer ring scraper 1 has a smaller radial cutting amount than the second outer ring scraper 2, it can be fixed using a support structure.

[0034] Preferably, the inner wall of the sleeve 7 is circular, and correspondingly, the outer wall of the drill rod 4 is circular. The use of cylindrical sleeve 7 and drill rod 4 not only meets the cutting feed requirements but also facilitates disassembly and maintenance.

[0035] Preferably, a plurality of axially extending grooves 14 are provided at the lower part of the drill bit rod 4. One end of the cutter head 301 is inserted into the groove 14 and fixed in the groove 14 by countersunk screws 15. The other end of the cutter head 301 is in contact with the inner wall of the ring 5 corresponding to the second outer ring scraper 2 and fixed in the inner wall of the ring 5 corresponding to the second outer ring scraper 2 by countersunk screws 15, so as to realize the detachable installation of the cutting drill bit 3 and facilitate disassembly and maintenance.

[0036] Preferably, the top of the upper scraper 6 protrudes from the top of the ring 5, and the bottom of the lower scraper 6 protrudes from the bottom of the ring 5, which effectively increases the axial scraping area of ​​the scraper 6 and further improves the quality of hole wall finishing and compaction.

[0037] Preferably, the drill bit 302 is made of high manganese alloy, which can effectively improve the structural strength of the drill bit 302 and extend its service life.

[0038] A drilling machine for drilling cast-in-place piles in deep silt strata includes the aforementioned rock drill bit, wherein the drill bit rod 4 of the rock drill bit is connected to the output end of the feed system of the drilling machine by means of bolts, flanges or pins, so as to realize the drilling of cast-in-place piles and effectively improve construction efficiency.

[0039] When the rock drill bit and drilling machine of this embodiment are used in construction in deep silty rock layers:

[0040] Slurry preparation: High-quality sodium-based bentonite (ratio 90-120 kg / m³) is used. 3 Add 0.8-1.2 kg / m³ 3 PAC thickener, controlling the mud specific gravity to 1.20-1.30 g / cm³ 3 With a viscosity of 25-30s and a sand content of <6%, the solution is stirred at high speed for 40 minutes and then allowed to stand for 36 hours to hydrate. During construction, the viscosity is dynamically adjusted to 28-32s according to the characteristics of the drill bit, and the circulation flow rate is controlled at 1.0-1.5m³. 3 / min, when drilling reaches the rock interface, PAC should be added immediately and the specific gravity increased to 1.25-1.35 g / cm³. 3 This ensures the synergistic effect of mud wall protection and the dual-mode cutting system. Its double-ring rock drill bit with drill teeth, combined with mud drilling, effectively guarantees the drill bit's drilling and wall protection capabilities in rock formations, significantly improving drilling accuracy and efficiency.

[0041] Drilling rig commissioning parameters: For its double-ring rock drill bit with drill teeth, to ensure construction quality and efficiency, the matching and adjustment of rotation speed and mechanical power are crucial during commissioning. To verify the most suitable parameters for the drill bit improvement, five test piles were constructed before construction. The table below compares the main performance parameters before and after the improvement in detail:

[0042] Comparison table of test pile results

[0043] Performance indicators conventional drill bits Double ring + tapered cutting teeth Double ring + tapered cutting teeth Operating speed (r / m) 40-50 40-50 30-40 Motor power (sludge) KW 20-30 25-28 22-25 Motor power (coarse sand) 60-80 55～75 55～75 Verticality (%) 1.0％～1.5％ ＜0.5％ ＜0.5％ Filling coefficient 1.40 1.20 1.15

[0044] The test pile results show that using a drill bit with double-ring tapered cutting teeth can effectively reduce the filling coefficient, the grouting inclination, and the motor power of the cast-in-place pile. Under the same drill bit conditions, reducing the rotational speed can effectively reduce power consumption and the filling coefficient.

[0045] During actual construction and commissioning, the rotation speed should be adjusted gradually. Initially, it should be controlled at 25-30 r / m, and gradually increased to 35 r / m after the equipment is running stably. If a harder stratum is encountered, the speed can be appropriately increased to 70-80 r / m. During construction, close attention should be paid to the drilling speed and power meter to ensure that the equipment operates under the best conditions. After every 5 pile holes are completed, the wear of the cutting teeth and the outer ring cutter of the drill bit can be checked to ensure that they continue to maintain good working performance.

[0046] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several modifications and improvements can be made without departing from the structure of the present utility model. These modifications and improvements will not affect the effectiveness of the present utility model or the practicality of the patent.

Claims

1. A rock drill bit for drilling cast-in-place piles in deep silt strata, characterized in that, The drill bit includes a first outer ring scraper (1), a second outer ring scraper (2), and a cutting drill bit (3). The cutting drill bit (3), the second outer ring scraper (2), and the first outer ring scraper (1) are mounted on the drill bit shaft (4) from bottom to top, and the first outer ring scraper (1) and the second outer ring scraper (2) are spaced apart. The cutting drill bit (3) and the second outer ring scraper (2) are detachably connected. The first outer ring scraper (1) and the second outer ring scraper (2) have the same structure, both including a ring (5) and multiple scraper blades (6). The ring (5) is detachably mounted on the periphery of the drill bit shaft (4), and the multiple scraper blades (6) are... The drill bit is divided into two layers, with each layer of scraper blades (6) evenly fixed on the outer wall of the ring (5). The diameter of the ring (5) corresponding to the second outer ring scraper (2) is smaller than the diameter of the ring (5) corresponding to the first outer ring scraper (1). The bottom of the drill rod (4) is a pointed structure. The cutting drill bit (3) includes multiple cutter discs (301). Each cutter disc (301) has multiple drill teeth (302) fixed on its outer wall. One end of each cutter disc (301) is detachably connected to the lower part of the drill rod (4), and the other end extends obliquely to the inner wall of the ring (5) of the second outer ring scraper (2) and is detachably connected to it.

2. The rock drill bit for drilling deep silt strata cast-in-place piles according to claim 1, characterized in that, The outer walls of the ring (5) and the scraper (6) are both inclined structures with a larger upper surface and a smaller lower surface.

3. The rock drill bit for drilling deep silt strata cast-in-place piles according to claim 1, characterized in that, The ring (5) is provided with a sleeve (7), and the sleeve (7) is fixedly connected to the ring (5) by multiple connecting rods (8). The sleeve (7) is slidably sleeved on the drill rod (4), and a locking structure is provided between the sleeve (7) corresponding to the second outer ring scraper (2) and the drill rod (4). A support structure is provided between each connecting rod (8) corresponding to the first outer ring scraper (1) and the second outer ring scraper (2).

4. The rock drill bit for drilling deep silt strata cast-in-place piles according to claim 3, characterized in that, The support structure includes a support rod (9), an upper support nut (10), and a lower support nut (11). One end of the support rod (9) is fixed to the top of the connecting rod (8) corresponding to the second outer ring scraper (2), and the other end slides through the connecting rod (8) corresponding to the first outer ring scraper (1). The upper support nut (10) and the lower support nut (11) are respectively threaded to the support rod (9) on the upper and lower sides of the connecting rod (8) corresponding to the first outer ring scraper (1), and the upper support nut (10) and the lower support nut (11) are both attached to the surface of the connecting rod (8) corresponding to the first outer ring scraper (1).

5. A rock drill bit for drilling deep silt strata cast-in-place piles according to claim 3, characterized in that, The locking structure includes two sets of locking bolts (12) and locking nuts (13). The two sets of locking bolts (12) and locking nuts (13) are arranged vertically and vertically. The locking bolts (12) pass through the sleeve (7) and the drill rod (4) and are threadedly connected to the locking nuts (13).

6. The rock drill bit for drilling deep silt strata cast-in-place piles according to claim 3, characterized in that, The inner wall of the sleeve (7) is circular, and correspondingly, the outer wall of the drill rod (4) is circular.

7. A rock drill bit for drilling deep silt strata cast-in-place piles according to claim 1, characterized in that, The lower part of the drill rod (4) has multiple axially extending grooves (14) extending to its bottom. One end of the cutter head (301) is inserted into the groove (14) and is fixed in the groove (14) by countersunk screws (15). The other end of the cutter head (301) is in contact with the inner wall of the ring (5) corresponding to the second outer ring scraper (2) and is fixed in the inner wall of the ring (5) corresponding to the second outer ring scraper (2) by countersunk screws (15).

8. The rock drill bit for drilling deep silt strata cast-in-place piles according to claim 1, characterized in that, The top of the upper scraper (6) protrudes from the top of the ring (5), and the bottom of the lower scraper (6) protrudes from the bottom of the ring (5).

9. A rock drill bit for drilling deep silt strata cast-in-place piles according to claim 1, characterized in that, The drill bit (302) is made of high manganese alloy.

10. A drilling machine for drilling cast-in-place piles in deep silt strata, characterized in that, The rock drill bit includes any one of claims 1-9.

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