A fan blade type super-large diameter rotary drill bit

Abstract

The application discloses a fan-shaped super-large-diameter rotary drilling head, and relates to the rotary drilling process technical field. The fan-shaped super-large-diameter rotary drilling head comprises a drill bit body, the drill bit body comprises a central body, the bottom of the central body is provided with a cutting disc, and the top of the central body is provided with a connecting square for connecting a drill rod. The fan-shaped super-large-diameter rotary drilling head further comprises reaming wings, the reaming wings are provided in a plurality of numbers, the reaming wings are evenly distributed on the side wall of the central body, and the bottom of the reaming wing is higher than the bottom of the central body. The bottom of the reaming wing and the cutting disc is provided with a tooth plate. The application increases the maximum diameter of the drill bit body, solves the problem that the current rotary drilling process is limited by the drill bit and cannot be applied to the super-large-diameter cast-in-place pile construction field, and widens the application market of the rotary drilling rig.

Description

Technical Field

[0001] This invention relates to the field of rotary drilling technology, and in particular to a fan-shaped ultra-large diameter rotary drilling bit. Background Technology

[0002] Currently, rotary drilling technology has been widely promoted and applied in the construction of urban high-rise buildings, subways, ring roads, light rail, highways, and high-speed railways in my country due to its significant advantages such as rapid construction, strong bearing capacity, low cost, and strong adaptability to different strata.

[0003] Large-diameter piles refer to bored piles with a diameter greater than or equal to 2.50 meters, while ultra-large-diameter piles refer to piles with a diameter greater than 3.5 meters.

[0004] Rotary drilling technology (rotary drilling rig, rotary drilling bit): A rotary drilling rig is a comprehensive drilling machine that can operate on various drilling depths and features fast hole-forming speed, low pollution, and high mobility. The rotary drilling rig uses a multi-layer telescopic drill rod, which reduces drilling auxiliary time, labor intensity, and eliminates the need for mud circulation and slag removal, saving costs. It is suitable for pile foundation construction in urban construction, bridges, and other projects. The rotary drilling bit is connected to the main body of the rotary drilling rig and is the main equipment used for drilling.

[0005] like Figure 3 As shown, the maximum drilling diameter of a rotary drilling rig is determined by the distance D between the drill rod center and the mast. If the radius of the drill bit used exceeds this distance, the drill bit bucket will interfere with the mast when it is lifted. Currently, the largest rotary drilling rig in China, the 800E, has a torque of 793 kN.m and a distance of 2500 mm between the drill rod center and the mast, meaning that the maximum allowable diameter for rotation is 5000 mm. Overcoming this distance limitation is the most critical technical challenge in achieving ultra-large diameter construction using rotary drilling technology.

[0006] Currently, the largest diameter rotary drilling bit produced domestically is... Cutting teeth and sand scooping bucket; the largest diameter of cast-in-place piles constructed by domestic rotary drilling rigs is... Currently, the common unloading method for sand dredging buckets in China is as follows: the drill rod lifts the drill bit to the top of the mast - the power head pressure plate opens the opening and closing mechanism of the drill bit - the bottom door is opened to unload soil and rotate to throw soil. Now, if we want to design an ultra-large diameter drill bit, if we use the conventional circular shape and opening and closing structure, it is impossible to lift the drill bit to the top of the mast, nor is it possible to open the entire bottom door of the drill bit by the pressure plate (the inner and outer diameter of the pressure plate is only 820mm / 1420mm, and the bottom door diameter of the drill bit is at least 3000mm), and it is impossible to rotate to throw soil.

[0007] The maximum torque of rotary drilling rig in the world is 793KN.m, and the maximum drill pipe-720 drill pipe weight is 40t, which limits the maximum weight of the drill bit to not more than 40t, and at the same time meets the lifting force of the drilling rig, and tries to reduce the weight of the drill bit as much as possible, and overcomes the problem of rotary lock of the drilling rig.

[0008] The maximum width of land transportation vehicle is 3m, and the maximum load is about 29t (excluding the weight of the vehicle body), how to solve the transportation problem is a big problem in the design of the drill bit.

[0009] Preventing hole deviation during drilling, i.e. how to center and guide, is an important part of the design of super large diameter drill bit.

[0010] With the rapid development of China's economy, the construction scale is continuously increasing, the building level is increasing day by day, the structure form design is changing day by day, and the requirement for pile foundation bearing capacity is higher and higher in the design of power, transportation and urban construction projects, resulting in larger and deeper pile foundation diameter, and a large number of super large diameter pile foundation designs.

[0011] With the rapid development of urban construction, a large number of large volume, large span, high super high buildings have emerged in densely populated urban space, and such buildings often have the characteristics of super large diameter rock-embedded pile foundation, large pile length, and large rock-embedded depth; In addition, it is also restricted by surrounding existing building foundation, subway tunnel (connection station) and other factors, and has strict requirements on piling vibration, blasting and underground water level change. How to complete the large diameter rock-embedded pile construction on the original ground under the premise of ensuring environmental protection, safe and civilized construction has become a technical difficulty to be solved.

[0012] In the face of the construction difficulty of super large diameter cast-in-place pile, exploration and attempt have been made at home and abroad, and many successful cases have been achieved, among which the following processes are currently used in China:

[0013] (1) Positive circulation process hole forming, i.e. using positive circulation diving drill to drill in stages, as shown in Figure 2 , mud or water enters from drill pipe 8, and carries drill cuttings and drill residues out of wellhead of pile hole 9;

[0014] (2) Reverse circulation drilling hole forming, using reverse circulation process to drill in stages, as shown in Figure 1 ;

[0015] (3) Manual hole digging + blasting;

[0016] (4) Large diameter steel pipe pile vibration hammer sinking process;

[0017] Due to the limitation of not having a super large diameter rotary drill bit that can match the rotary drilling rig, the rotary drilling process has not been applied to the field of super large diameter cast-in-place pile construction.

[0018] However, the prior art has the following disadvantages:

[0019] (1) The disadvantages of the positive circulation process for hole forming are: 1. Because the pile hole cross-sectional area is large, the drilling resistance is large during drilling; 2. Because the drilling residue is large, when the mud wall is formed by positive circulation drilling, the mud in the super large diameter drill hole of the cast-in-place pile rises slowly, and if the mud index is not properly controlled or not completely emptied, the thickness of the hole bottom sediment is too large; 3. Because the self-stability of the hole wall of the super large diameter drill hole is relatively poor, the hole wall is prone to collapse.

[0020] (2) The disadvantages of reverse circulation drilling for hole forming are: 1. Because the gravel is large, the drill bit center pipe is easily blocked; 2. Because multiple reaming is required, the drill is easily blocked at the beginning of the staged reaming; 3. Because the broken area is too large, the cutter is easily worn.

[0021] (3) The disadvantages of manual hole digging + blasting are: 1. Because a large area of pile hole is excavated, the stability of the soil during pile hole forming is difficult to guarantee; 2. Because the blasting disturbs the stratum too much, it has a negative impact on surrounding buildings and living environment, and is not suitable for popularization and application.

[0022] (4) The disadvantages of the vibration hammer pile sinking process are: 1. Because the super large diameter steel pipe pile is heavy, large-scale piling and lifting equipment is required on site, and the cost is high; 2. Because the process is vibration sinking, the ground resistance is large, and it cannot be applied to hard strata.

[0023] Therefore, it is urgent to provide a fan-shaped super large diameter rotary drill bit to solve the above problems in the prior art. SUMMARY

[0024] The purpose of the present application is to provide a fan-shaped super large diameter rotary drill bit, which increases the maximum diameter of the drill bit body, solves the problem that the current rotary drilling process is limited by the drill bit and cannot be applied to the super large diameter cast-in-place pile construction field, and broadens the application market of the rotary drilling rig.

[0025] To achieve the above purpose, the present application provides the following scheme: the present application provides a fan-shaped super large diameter rotary drill bit, which comprises a drill bit body, the drill bit body comprises a center body, the bottom of the center body is provided with a cutting disc, and the top of the center body is provided with a connecting square for connecting a drill rod; further comprising a reaming wing, the reaming wing is provided with a plurality of reaming wings, the plurality of reaming wings are evenly distributed on the side wall of the center body, and the bottom of the reaming wing is higher than the bottom of the center body; the bottom of the reaming wing and the cutting disc is provided with a tooth plate.

[0026] Preferably, an upper disc is arranged above the center body, an upper rib plate is arranged above the upper disc, the bottom of the upper rib plate is connected with the upper disc, and the inner side of the upper rib plate is connected with the side wall of the connecting square.

[0027] Preferably, the connecting side is provided with the upper rib plate on both sides, and the upper rib plates on both sides of the connecting side are symmetrically arranged; the connecting side is provided with two upper rib plates on each side, and the two upper rib plates on each side are arranged in a V shape.

[0028] Preferably, the tooth plate is an integral tooth plate, the tooth plate at the bottom of the cutting disc is arranged in a conical shape, and the tooth plate at the bottom of the reaming wing is arranged horizontally.

[0029] Preferably, a plurality of cutting teeth are arranged on the tooth plate.

[0030] Preferably, the reaming wing is provided with two, and the two reaming wings are symmetrically arranged on both sides of the center body; the two reaming wings are arranged perpendicularly to the upper disc.

[0031] Preferably, the reaming wing is arranged separately from the center body, the reaming wing is welded to the center body during construction, and a reinforcing rib plate is welded above the reaming wing.

[0032] Preferably, the diameter of the center body is 3500mm, and the diameter of the drill bit body is 5800mm.

[0033] Preferably, the center body is advanced and guided before the drill bit body is drilled.

[0034] The present application has the following beneficial technical effects relative to the prior art:

[0035] (1) The drill bit body adopts a "fan type" structure, and the drill bit can be lifted above the mast for operation during construction, solving the problem that the maximum diameter of the drilled hole is long-term limited by the distance between the center of the drill rod and the mast.

[0036] (2) Whether the center body or the reaming wing is designed as an integral tooth plate, the full-face crushing is reduced, and the drilling resistance in the drilling process is reduced.

[0037] (3) When single-pass drilling is performed, the center body bottom door of the rotary drilling rig is reversed to close, and the residue can be lifted up for carrying, without the need for mud circulation and residue removal.

[0038] (4) The center body is advanced and guided during drilling, and the drilling deviation phenomenon does not occur.

[0039] (5) The diameter of the center body can reach 3500mm, without the need for multi-stage reaming, without the occurrence of drilling accidents, and the drilling time is reduced.

[0040] (6) Mud protection can be used during drilling, the stability of the pile hole soil body is strong, and the disturbance to the stratum is small.

[0041] (7) The construction process does not need large piling and hoisting equipment on site, and the cost is low.

[0042] (8) The cutting tool is equipped with a cutting pick, and can drill into hard rock layers, and has strong stratum applicability. BRIEF DESCRIPTION OF DRAWINGS

[0043] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the embodiments will be briefly introduced below. Obviously, the drawings in the following description only constitute some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative effort on the basis of these drawings.

[0044] Figure 1 It is a schematic diagram of the reverse circulation drilling process in the prior art;

[0045] Figure 2 It is a schematic diagram of the positive circulation drilling process in the prior art;

[0046] Figure 3 It is a schematic diagram of the maximum drilling diameter of the drilling machine in the prior art;

[0047] Figure 4 It is a structural schematic diagram of the fan-shaped super-large diameter rotary drill bit of the present application;

[0048] Figure 5 It is a front view of the fan-shaped super-large diameter rotary drill bit of the present application;

[0049] Figure 6 It is a top view of the fan-shaped super-large diameter rotary drill bit of the present application;

[0050] Figure 7 It is a first schematic diagram of the connection between the central body and the upper disc of the present application;

[0051] Figure 8 It is a second schematic diagram of the connection between the central body and the upper disc of the present application;

[0052] Figure 9 It is a front view of the connection between the central body and the upper disc of the present application;

[0053] Figure 10 It is a side view of the connection between the central body and the upper disc of the present application;

[0054] Figure 11 It is a top view of the connection between the central body and the upper disc of the present application;

[0055] Figure 12 It is a schematic diagram of the central body of the present application;

[0056] Among them, 1. Connecting side; 2. Upper stiffening plate; 3. Upper plate; 4. Central body; 5. Cutting disc; 6. Hole reamer; 7. Reinforcing stiffening plate; 8. Drill rod; 9. Pile hole. Detailed Implementation

[0057] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0058] The purpose of this invention is to provide a fan-shaped ultra-large diameter rotary drilling bit, which increases the maximum diameter of the drill bit body, solves the problem that the current rotary drilling technology is limited by the drill bit and cannot be applied to the construction of ultra-large diameter cast-in-place piles, and expands the application market of rotary drilling rigs.

[0059] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0060] Example 1

[0061] like Figures 4-12 As shown, this embodiment provides a fan-shaped ultra-large diameter rotary drilling bit, including a drill bit body, which includes a central body 4. A cutting disk 5 is provided at the bottom of the central body 4, and a connecting plate 1 is provided at the top of the central body 4 for connecting the drill rod. It also includes a reaming wing 6, of which a plurality of reaming wings 6 are provided, which are evenly distributed circumferentially on the side wall of the central body 4. The bottom of the reaming wings 6 is higher than the bottom of the central body 4. The bottom of the reaming wings 6 and the cutting disk 5 are both provided with toothed plates.

[0062] In this embodiment, an upper plate 3 is provided above the central body 4, and an upper stiffening plate 2 is provided above the upper plate 3. The bottom of the upper stiffening plate 2 is connected to the upper plate 3, the inner side of the upper stiffening plate 2 is connected to the side wall of the connecting unit 1, and the outer side extends along the upper plate 3. Specifically, two upper stiffening plates 2 are provided on both sides of the connecting unit 1, and the upper stiffening plates 2 on both sides of the connecting unit 1 are symmetrically arranged, with the two upper stiffening plates 2 on each side arranged in a V-shape.

[0063] In this embodiment, the toothed plate is an integral toothed plate, the toothed plate at the bottom of the cutting disk 5 is tapered, and the toothed plate at the bottom of the reaming wing 6 is horizontal; multiple cutting teeth are provided on the toothed plate.

[0064] In the embodiment, the reaming wings 6 are preferably provided with two, which are symmetrically arranged on both sides of the central body; the two reaming wings 6 are arranged perpendicularly to the upper disc 3, forming a fan-like structure; the cross section of the conventional rotary drill bit is circular, so that the maximum diameter of the drilled hole is long-term limited by the distance between the center of the drill rod and the mast, and the "fan-like" structure in the embodiment solves this problem; in the construction process, the mast passes through the gap between the "fan blades", and the drill bit body can be lifted above the mast for operation.

[0065] In the embodiment, the reaming wings 6 are arranged separately from the central body 4, which is convenient for separate transportation, while the central body 4 and the upper disc 3 can be combined for transportation; after being transported to the construction site, the reaming wings 6 are welded and connected with the central body 4, and the reinforcing rib plate 7 is welded above the reaming wings 6.

[0066] In the embodiment, the diameter of the central body 4 is 3500mm, and the diameter of the drill bit body is 5800mm.

[0067] In the embodiment, the central body is advanced before the drill bit body drills a hole, which avoids drilling a deviated hole and reduces the drilling resistance;

[0068] Specifically, as shown in the figure, Figure 12 in the construction process, first, a drill bit with a conventional structure is used to drill a hole with a D1 diameter (the maximum hole diameter that can be drilled at present is ), and then the drill bit body of the embodiment is lowered to drill a hole with a D2 diameter (the D2 diameter can reach ), and H2>H1 is designed (the advanced length can be adjusted according to the D2 diameter, and the larger the D2 diameter is, the smaller the recommended H2 advanced length is); the advanced part directly enters the drilled hole that has been completed, so that the drilling is concentric and the drilling is in the form of an even strip, which reduces the drilling resistance and ensures the drilling perpendicularity.

[0069] In the embodiment, when single-pass drilling is performed, the rotary drilling rig is reversed, and the bottom door of the central body 4 is closed, so that the drilling rig can be lifted to carry the residue, and mud circulation is not required for residue removal.

[0070] Specifically, the bottom of the central body 4 is provided with a double-layer bottom plate, i.e., an upper bottom plate and a lower bottom plate; the upper bottom plate is fixedly welded to the barrel of the central body 4, and the lower bottom plate is connected to the upper bottom plate through a central shaft; the upper bottom plate and the lower bottom plate are both provided with a soil inlet; when normal drilling is performed, the soil inlets of the upper bottom plate and the lower bottom plate coincide, and the drilling residue enters the inside of the drill bit through the soil inlets; after drilling is completed, the drilling rig is reversed to cause the upper bottom plate and the lower bottom plate to be dislocated; the lower bottom plate is limited by a limiting block and can just block the soil inlet of the upper bottom plate, thereby completing the residue carrying function.

[0071] The fan-shaped super-large-diameter rotary drill bit increases the maximum diameter of the rotary drill bit from the current 3500mm to 5800mm, further perfects the rotary drilling construction process, solves the problem that the current rotary drilling process cannot be applied to the super-large-diameter cast-in-place pile construction field due to the limitation of the drill bit, widens the application market of the rotary drilling rig, provides a low-cost, short-period and high-quality construction process for the society, and contributes to the economic construction of China.

[0072] It is to be understood that the present application is not limited to the details of the above-exemplified embodiments and can be implemented in other concrete forms without departing from the spirit or essential characteristics of the present application. Accordingly, no matter from which point of view, the embodiments should be considered as exemplary and non-limiting, and the scope of the present application is defined by the appended claims rather than the above description, and therefore all changes falling within the meaning and range of the equivalent elements of the claims are intended to be embraced in the present application, and any reference signs in the claims should not be considered as limiting the involved claims.

[0073] The principles and implementation manners of the present application are described by applying specific examples in the present application, and the above-mentioned examples are only used to help understand the method of the present application and its core idea; meanwhile, for the general skilled in the art, according to the idea of the present application, the specific implementation manners and application ranges will have changes. In conclusion, the content of the present description should not be understood as the limitation of the present application.

Claims

1. A fan blade type super large diameter rotary drill bit, comprising a bit body, the bit body comprising a center body, the bottom of the center body being provided with a cutting disc, and the top of the center body being provided with a connecting square for connecting a drill rod; characterized in that: Further comprising reaming wings, the reaming wings are provided with several, several of the reaming wings are distributed on the side wall of the center body, the bottom of the reaming wing is higher than the bottom of the center body; The bottom of the reaming wing and the cutting disc are provided with a tooth plate; The upper part of the center body is provided with an upper disc, the reaming wing is provided with two, two of the reaming wing are symmetrically arranged on both sides of the center body; Two reaming wings and the upper disc are vertically arranged to form a fan-shaped structure, so that the mast can pass through the gap between the reaming wing and the upper disc; The bottom of the center body is provided with an upper bottom plate and a lower bottom plate, the upper bottom plate is fixedly welded with the cylinder of the center body, the lower bottom plate is connected with the upper bottom plate through a center shaft, the upper bottom plate and the lower bottom plate are provided with a soil inlet, when drilling normally, the soil inlets of the upper bottom plate and the lower bottom plate coincide, the drilling slag enters the inside of the drill bit from the soil inlet, after drilling is completed, the drilling machine is reversed, driving the upper bottom plate and the lower bottom plate to be dislocated, the lower bottom plate is limited by a limiting block, which can block the soil inlet of the upper bottom plate, completing the carrying of the slag function.

2. The fan blade type ultra-large diameter rotary drill bit according to claim 1, characterized in that: The upper part of the upper disc is provided with an upper rib plate, the bottom of the upper rib plate is connected with the upper disc, the inner side of the upper rib plate is connected with the side wall of the connecting side.

3. The fan blade type ultra-large diameter rotary drill bit according to claim 2, characterized in that: The connecting side is provided with the upper rib plate on both sides, the upper rib plates on both sides of the connecting side are symmetrically arranged; The connecting side is provided with two upper rib plates on both sides, two upper rib plates on each side are arranged in V shape.

4. The fan blade type ultra-large diameter rotary drill bit according to claim 1, wherein: The tooth plate is an integral tooth plate, the tooth plate at the bottom of the cutting disc is arranged in a conical shape, and the tooth plate at the bottom of the reaming wing is arranged horizontally.

5. The fan blade type ultra-large diameter rotary drill bit according to claim 1 or 4, characterized in that: A plurality of cutting teeth are arranged on the tooth plate.

6. The fan blade type ultra-large diameter rotary drill bit according to claim 2, wherein: The reaming wing is separately arranged with the center body, the reaming wing is welded and connected with the center body during construction; The upper part of the reaming wing is welded with a reinforcing rib plate.

7. The fan blade type ultra-large diameter rotary drill bit according to claim 1, wherein: The diameter of the center body is 3500mm, and the diameter of the drill bit body is 5800mm.

8. The fan blade type ultra-large diameter rotary drill bit according to claim 1, wherein: The center body is advanced before drilling the drill bit body.

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