A cast-in-place pile hard rock rotary drilling and step-by-step hole expansion drilling tool

Abstract

The present application relates to a bored pile hard rock rotary drilling and step-by-step hole expansion drill, which belongs to the field of bored pile construction, and includes a drilling bit and a guide drill bit, wherein the guide drill bit is coaxially and detachably connected to the drilling bit, a matching groove for inserting the guide drill bit is coaxially provided on one end of the drilling bit, a rotary drilling accommodating chamber is provided on the drilling bit, a connecting hole is provided on the groove wall of the matching groove, a storage chamber is provided in the guide drill bit, a docking hole is provided on the side wall of the guide drill bit, the connecting hole is connected to the rotary drilling accommodating chamber, the docking hole is connected to the storage chamber, and when the drilling bit and the guide drill bit are connected, the docking hole and the connecting hole are aligned. The internal space of the guide drill bit of the present application can receive and accommodate the rock and soil materials entering the drilling bit, thereby increasing the excavation volume of the drilling tool during a single rotary drilling and improving the drilling efficiency.

Description

Technical Field

[0001] The present application relates to the field of bored pile construction, and in particular to a bored pile hard rock rotary drilling and step-by-step hole expansion drill. Background Art

[0002] When encountering a medium to slightly weathered hard rock bearing layer during the drilling process of large-diameter rotary bored piles, the rotary bored pile graded hole expansion drilling process is usually adopted, that is, a small-diameter rotary bored drill is used to drill from the center of the pile position until the bottom of the pile hole reaches the designed elevation, and then the diameter of the pile hole is gradually expanded until the designed pile diameter is reached. When the medium to slightly weathered rock layer is broken or cracks are developed, or there is an inclined rock surface, it is difficult to control the verticality of the pile hole during the graded hole expansion drilling process, and it is easy to have a deviated hole when expanding into the rock.

[0003] In response to the above problems, a Chinese utility model patent with announcement number CN213807570U discloses a combined drill bit for rotary drilling and graded hole formation, whose structure includes a drilling bit and a guide drill bit that are detachably connected to each other. When expanding the hole, a guide drill bit that is consistent with the size of the existing small-diameter pile hole is installed in the middle end of the drilling bit.

[0004] After the drilling bit and the guide drill bit are installed, the guide drill bit occupies too much of the middle space of the drilling bit, and the amount of soil that can be excavated in a single drilling is limited, resulting in low drilling efficiency. Summary of the invention

[0005] In order to improve the above-mentioned problems, the present application provides a cast-in-place pile hard rock rotary drilling and step-by-step hole expansion drill.

[0006] The present application provides a cast-in-place pile hard rock rotary drilling and step-by-step hole expansion drilling tool adopts the following technical solution: A cast-in-place pile hard rock rotary drilling and step-by-step hole expansion drill tool comprises a drilling bit and a guide drill bit, wherein the guide drill bit is coaxially and detachably connected to the drilling bit, a matching groove for inserting the guide drill bit is coaxially formed at one end of the drilling bit, a rotary drilling accommodating chamber is formed on the drilling bit, a connecting hole is formed on the groove wall of the matching groove, a storage chamber is formed in the guide drill bit, a docking hole is formed on the side wall of the guide drill bit, the connecting hole is connected to the rotary drilling accommodating chamber, the docking hole is connected to the storage chamber, and when the drilling bit and the guide drill bit are connected, the docking hole and the connecting hole are aligned.

[0007] Preferably, a positioning rib is connected to the groove wall of the mating groove, and the length direction of the positioning rib is parallel to the axis of the drilling bit. A positioning groove is opened on the side wall of the guide drill bit, and the length direction of the positioning groove is parallel to the length direction of the guide drill bit. The positioning groove is for the positioning rib to slide into, and the drilling bit is penetrated by a mounting bolt, which is threadedly connected to the guide drill bit after being inserted into the drilling bit.

[0008] Preferably, the positioning rib and the groove wall of the matching groove are slidably connected, and the sliding direction is the circumferential direction of the drilling bit. A residual spring is connected between the positioning rib and the drilling bit, and the expansion and contraction direction of the residual spring is the circumferential direction of the drilling bit. The drilling bit includes a main barrel portion and a core disk portion which are coaxially rotatably connected to each other, the groove wall of the matching groove is located at the main barrel portion, the groove bottom of the matching groove is located at the core disk portion, the mounting bolt is located on the core disk portion, and the length direction of the mounting bolt is parallel to the axial direction of the drilling bit.

[0009] Preferably, a reinforcing partition is provided inside the guide drill bit, the plate surface of the reinforcing partition is perpendicular to the axial direction of the guide drill bit, the reinforcing partition is in contact with the inner wall of the storage cavity, and a clearance hole is opened on the reinforcing partition.

[0010] Preferably, a plurality of the reinforcing baffles are arranged along the axial direction of the guide drill bit, and the apertures of the clearance holes on the reinforcing baffles arranged along the vertical downward direction gradually decrease.

[0011] Preferably, a buffer ring is connected to the wall of the storage cavity on the guide drill bit, and a buffer spring is provided on the buffer ring. One end of the buffer spring is connected to the buffer ring, and the other end is connected to the reinforcing partition.

[0012] Preferably, an assembly groove is provided on the edge of the buffer ring, the depth direction of the assembly groove is the radial direction of the buffer ring, an assembly hole is provided on the side wall of the guide drill bit, an assembly block is passed through the side wall of the guide drill bit through the assembly hole, and the assembly block passes through the assembly hole and the assembly groove at the same time.

[0013] Preferably, an elastic block is fixedly connected to one end of the assembly block facing the bottom of the assembly groove, the elastic block abuts against the bottom of the assembly groove, and a mating ball is embedded in the end of the assembly block facing away from the elastic block, and the mating ball abuts against the groove wall of the mating groove.

[0014] The present application includes at least one of the following beneficial technical effects: 1. Through the provision of the storage cavity, the connection hole and the docking hole, the internal space of the pilot drill bit can also be used for the rock and soil materials entering the rotary drilling accommodating cavity to enter and store, so that the amount of rock and soil excavated in a single drilling is increased, thereby improving the drilling efficiency; 2. By setting up the reinforcing baffles, the lateral structural strength of the guide drill bit is strengthened. At the same time, the reinforcing baffles at different positions are provided with holes of different sizes to allow rock and soil materials of different particle sizes to pass through. The passability of large rock and soil materials is poor, which can reduce the impact damage of large rock and soil materials on the bottom wall of the storage chamber. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1It is a schematic cross-sectional view of the structure used to illustrate the step-by-step hole expansion drill bit of the cast-in-place pile hard rock rotary drilling in the embodiment of the present application when entering the pile hole.

[0016] Figure 2 It is a schematic diagram of the cross-sectional structure of a hard rock rotary drilling and step-by-step hole expansion drill for cast-in-place piles in an embodiment of the present application.

[0017] Figure 3 It is a schematic cross-sectional view of the structure of the guide drill bit in the embodiment of the present application.

[0018] Explanation of the accompanying drawings: 1. Drill bit; 11. Main cylinder; 12. Core disk; 13. Rotary drilling chamber; 14. Matching groove; 141. Connecting hole; 15. Positioning rib; 151. Allowance spring; 16. Mounting bolt; 2. Guide drill bit; 21. Storage chamber; 22. Docking hole; 23. Positioning groove; 24. Assembly hole; 3. Strengthening partition; 31. Make way hole; 32. Buffer ring; 33. Buffer spring; 34. Assembly groove; 35. Assembly plug; 351. Elastic block; 352. Matching ball. DETAILED DESCRIPTION

[0019] The following is combined with Figure 1-3 This application is described in further detail.

[0020] The present application embodiment discloses a cast-in-place pile hard rock rotary drilling and step-by-step hole expansion drilling tool, such as Figure 1 and 2 As shown, it includes a drilling bit 1 and a pilot drill bit 2. The diameter of the drilling bit 1 is larger than the diameter of the pilot drill bit 2. The diameter of the pilot drill bit 2 is consistent with the size of the existing small-diameter pile hole. During hole expansion drilling, the pilot drill bit 2 is coaxially detachably connected to the drilling bit 1, and the lower end of the pilot drill bit 2 is lower than the lower end of the drilling bit 1. The pilot drill bit 2 is used to improve the coaxiality of the drilling tool and the existing small-diameter pile hole.

[0021] like Figure 1 and 2As shown, the drilling bit 1 and the guide drill bit 2 are detachably connected, and the drilling bit 1 includes a main barrel portion 11 and a core disk portion 12 which are coaxially rotatably connected to each other. The core disk portion 12 is located at the upper position of the inner side of the main barrel portion 11, and a matching groove 14 is formed therebetween. The groove wall of the matching groove 14 is located on the inner side of the main barrel portion 11, and the groove bottom of the matching groove 14 is located on the lower side of the core disk portion 12, so that the groove opening of the quota groove faces downward; the connection position of the drill rod and the drill tool is the top end surface of the main barrel portion 11. The matching groove 14 is for inserting the pilot drill bit 2, which is a hollow cylinder with a storage cavity 21 therein; four positioning ribs 15 are connected to the groove wall of the matching groove 14, and the length direction of the positioning ribs 15 is parallel to the axis of the drilling drill bit 1, and four positioning grooves 23 are provided on the outer wall of the pilot drill bit 2, and the length direction of the positioning grooves 23 is parallel to the length direction of the pilot drill bit 2. When the pilot drill bit 2 enters the matching groove 14, the positioning grooves 23 are for the positioning ribs 15 to slide into. The core disk portion 12 of the drilling drill bit 1 is penetrated with a mounting bolt 16, and the length direction of the mounting bolt 16 is parallel to the axial direction of the drilling drill bit 1. After the mounting bolt 16 is inserted into the core disk portion 12, it is threadedly connected with the pilot drill bit 2, so that the pilot drill bit 2 and the core disk portion 12 are connected to each other.

[0022] like Figure 1 and 2 As shown, the positioning rib 15 and the groove wall of the matching groove 14 are slidably connected, and the sliding direction is the circumferential direction of the drilling bit 1. A residual spring 151 is connected between the positioning rib 15 and the drilling bit 1, and the expansion and contraction direction of the residual spring 151 is the circumferential direction of the drilling bit 1, so that the guide drill bit 2 has a certain rotational activity space relative to the drilling bit 1; during the drilling process, since the drilling bit 1 and the guide drill bit 2 are not rigidly fixed, the negative impact of the obstruction effect on the two on each other is weakened.

[0023] like Figure 1 and 2 As shown, the excavation tooth structures of the pilot drill bit 2 and the drilling drill bit 1 are both located at the bottom, the drilling drill bit 1 is provided with a rotary excavation accommodating chamber 13, and a through hole (not shown in the figure) is provided below the drilling drill bit 1 for the rock and soil after excavation to enter the rotary excavation accommodating chamber 13. Four connecting holes 141 are provided on the groove wall of the matching groove 14, and the connecting holes 141 are connected to the rotary excavation accommodating chamber 13. Four docking holes 22 are provided on the side wall of the pilot drill bit 2, and the docking holes 22 are connected to the storage chamber 21. When the drilling drill bit 1 and the pilot drill bit 2 are connected, the docking holes 22 and the connecting holes 141 are aligned, so that the rotary excavation accommodating chamber 13 and the storage chamber 21 are connected. When the height of the rock and soil in the rotary excavation accommodating chamber 13 reaches the connecting holes 141, the rock and soil material can cross the connecting holes 141 and enter the storage chamber 21.

[0024] like Figure 1 and 3As shown, a plurality of reinforcing baffles 3 are arranged in the guide drill bit 2, and the plate surface of the reinforcing baffles 3 is perpendicular to the axial direction of the guide drill bit 2. The reinforcing baffles 3 are in contact with the inner side wall of the storage chamber 21. When the guide drill bit 2 is subjected to a lateral force, the reinforcing baffles 3 play a certain strength supporting role on the side wall of the guide drill bit 2, thereby improving the structural stability of the guide drill bit 2. A plurality of reinforcing baffles 3 are arranged along the axial direction of the guide drill bit 2. In this embodiment, there are three reinforcing baffles 3, and the three reinforcing baffles 3 are all lower than the docking hole 22. The reinforcing baffles 3 are provided with clearance holes 31, and the apertures of the clearance holes 31 on each reinforcing baffle 3 arranged in the vertical downward direction gradually decrease. The smaller the particle size of the rock and soil material entering the storage chamber 21, the stronger the passability of each reinforcing baffle 3. The passability of large pieces of rock and soil material is poor, which can reduce the impact damage of large pieces of rock and soil material on the bottom wall of the storage chamber 21.

[0025] like Figure 1 and 3 As shown, the guide drill bit 2 is connected to the cavity wall of the storage cavity 21 with a number of buffer rings 32 corresponding to the strengthening baffle 3. The buffer ring 32 and the guide drill bit 2 are coaxial. A buffer spring 33 is provided on the buffer ring 32. One end of the buffer spring 33 is connected to the buffer ring 32, and the other end is connected to the strengthening baffle 3. The strengthening baffle 3 is located below the buffer ring 32. When the strengthening baffle 3 is impacted by rock and soil, the buffer spring 33 buffers the force on the strengthening baffle 3, thereby improving the durability of the strengthening baffle 3. An assembly groove 34 is provided on the edge of the buffer ring 32, and the depth direction of the assembly groove 34 is the radial direction of the buffer ring 32. An assembly hole 24 is provided on the side wall of the guide drill bit 2, and an assembly plug 35 is passed through the side wall of the guide drill bit 2 through the assembly hole 24. The assembly plug 35 passes through the assembly hole 24 and the assembly groove 34 at the same time, thereby realizing the axial positioning of the guide drill bit 2 and the buffer ring 32; when the drilling bit 1 is inserted into the matching groove 14, the assembly plug 35 cannot be withdrawn, so the guide drill bit 2 and the buffer ring 32 can be relatively fixed, and the number of assembly plugs 35 on a single buffer ring 32 is two. An elastic block 351 made of rubber is fixedly connected to one end of the assembly block 35 facing the bottom of the assembly groove 34, and the elastic block 351 abuts against the bottom of the assembly groove 34. A matching ball 352 is embedded in the end of the assembly block 35 facing away from the elastic block 351. When the guide drill bit 2 is located in the assembly groove 34, the matching ball 352 rolls and abuts against the groove wall of the matching groove 14. During the rotary drilling process, the inner wall of the assembly groove 34 causes less damage to the assembly block 35.

[0026] The implementation principle of a cast-in-place pile hard rock rotary drilling and step-by-step hole expansion drill tool in the embodiment of the present application is: Before drilling, the pilot drill bit 2 and the drilling drill bit 1 are connected to each other and drilling is carried out, and the lower end of the pilot drill bit 2 is inserted into the existing small-diameter pile hole. The rock and soil structure of the pile hole wall is scraped off by the drilling drill bit 1 and then enters the rotary drilling accommodating chamber 13 and the storage chamber 21 for storage. When the rock and soil in the pilot drill bit 2 almost fills the storage chamber 21, a single drilling contact is made, the drill tool is lifted out of the pile hole, and the installation bolts 16 are unscrewed, and the pilot drill bit 2 can be removed.

[0027] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A cast-in-place pile hard rock rotary drilling and step-by-step hole enlargement drilling tool, comprising a drilling bit (1) and a guide bit (2), wherein the guide bit (2) is coaxially detachably connected to the drilling bit (1), one end of the drilling bit (1) is coaxially provided with a matching groove (14) for inserting the guide bit (2), and the drilling bit (1) is provided with a rotary drilling accommodating chamber (13), characterized in that: A connecting hole (141) is provided on the groove wall of the matching groove (14), a storage chamber (21) is provided in the guide drill bit (2), a docking hole (22) is provided on the side wall of the guide drill bit (2), the connecting hole (141) is connected to the rotary drilling accommodating chamber (13), the docking hole (22) is connected to the storage chamber (21), and when the drilling bit (1) and the guide drill bit (2) are connected, the docking hole (22) and the connecting hole (141) are aligned.

2. The cast-in-place pile hard rock rotary drilling and step-by-step hole expansion drilling tool according to claim 1, characterized in that: A positioning rib (15) is connected to the groove wall of the matching groove (14), and the length direction of the positioning rib (15) is parallel to the axis of the drilling bit (1). A positioning groove (23) is provided on the side wall of the guide drill bit (2), and the length direction of the positioning groove (23) is parallel to the length direction of the guide drill bit (2). The positioning groove (23) is for the positioning rib (15) to slide into. A mounting bolt (16) is passed through the drilling bit (1), and the mounting bolt (16) is threadedly connected to the guide drill bit (2) after being inserted into the drilling bit (1).

3. The cast-in-place pile hard rock rotary drilling and step-by-step hole expansion drilling tool according to claim 2, characterized in that: The positioning rib (15) and the groove wall of the matching groove (14) are slidably connected, and the sliding direction is the circumferential direction of the drilling bit (1). A residual spring (151) is connected between the positioning rib (15) and the drilling bit (1), and the expansion and contraction direction of the residual spring (151) is the circumferential direction of the drilling bit (1). The drilling bit (1) comprises a main body cylinder (11) and a core disk (12) which are coaxially rotatably connected to each other. The groove wall of the matching groove (14) is located on the main body cylinder (11), and the groove bottom of the matching groove (14) is located on the core disk (12). The mounting bolt (16) is located on the core disk (12), and the length direction of the mounting bolt (16) is parallel to the axial direction of the drilling bit (1).

4. A cast-in-place pile hard rock rotary drilling and step-by-step hole expansion drill according to any one of claims 1 to 3, characterized in that: A reinforcing partition (3) is provided inside the guide drill bit (2), the plate surface of the reinforcing partition (3) is perpendicular to the axial direction of the guide drill bit (2), the reinforcing partition (3) is in contact with the inner wall of the storage cavity (21), and a clearance hole (31) is opened on the reinforcing partition (3).

5. The cast-in-place pile hard rock rotary drilling and step-by-step hole expansion drilling tool according to claim 4, characterized in that: A plurality of the reinforcing baffles (3) are arranged along the axial direction of the guide drill bit (2), and the apertures of the clearance holes (31) on the reinforcing baffles (3) arranged in the vertical downward direction gradually decrease.

6. The cast-in-place pile hard rock rotary drilling and step-by-step hole expansion drilling tool according to claim 4, characterized in that: The guide drill bit (2) is connected to a buffer ring platform (32) on the cavity wall of the storage cavity (21), and a buffer spring (33) is provided on the buffer ring platform (32). One end of the buffer spring (33) is connected to the buffer ring platform (32), and the other end is connected to the strengthening partition (3).

7. The cast-in-place pile hard rock rotary drilling and step-by-step hole expansion drilling tool according to claim 6, characterized in that: The edge of the buffer ring (32) is provided with an assembly groove (34), the depth direction of the assembly groove (34) is the radial direction of the buffer ring (32), the side wall of the guide drill bit (2) is provided with an assembly hole (24), the side wall of the guide drill bit (2) is penetrated by an assembly plug (35) through the assembly hole (24), and the assembly plug (35) passes through the assembly hole (24) and the assembly groove (34) at the same time.

8. The cast-in-place pile hard rock rotary drilling and step-by-step hole expansion drilling tool according to claim 7, characterized in that: An elastic block (351) is fixedly connected to one end of the assembly plug-in block (35) facing the bottom of the assembly groove (34), and the elastic block (351) abuts against the bottom of the assembly groove (34). A matching ball (352) is embedded in one end of the assembly plug-in block (35) facing away from the elastic block (351), and the matching ball (352) abuts against the groove wall of the matching groove (14).

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