Grading-free integrated drill bit

Abstract

The utility model relates to the technical field of pile foundation construction, in particular to a grading-free integrated drill bit which comprises a mounting shaft, an outer cylinder, a middle cylinder and a righting drill bit are sequentially and fixedly mounted on the outer surface of the mounting shaft from top to bottom, and the diameters of the outer cylinder, the middle cylinder and the righting drill bit are sequentially reduced. According to the grading-free integrated drill bit, the righting drill bit with the small diameter at the front end is firstly used for drilling, loosening the circumference of a rock core in a hole and increasing the free surface of a rock stratum so as to reduce the stress level of the righting drill bit, further drilling of a large-diameter barrel drill is facilitated, the working efficiency of the large-diameter barrel drill is improved, and meanwhile a free surface for rock mass breaking is manufactured for the righting drill bit for middle barrel drilling; the cone on the middle cylinder forms a rock mass crushing free surface for the outer cylinder, and the drill bit sequentially utilizes more than two drill bits to alternately work, so that the free surfaces can be provided mutually, the drilling efficiency is greatly improved, and the rock crushing capability is also improved.

Description

Technical Field

[0001] This utility model relates to the field of pile foundation construction technology, specifically to a grade-free integrated drill bit. Background Technology

[0002] Pile foundation construction technology is a crucial aspect of building engineering quality. Currently, there are two main types of hole-forming methods in pile foundation construction in my country: driven pipe drilling and borehole drilling. The choice of pile foundation hole-forming method is mainly based on geological conditions, construction period requirements, and pile foundation design, while also considering construction safety, quality, and cost control. Driven pipe drilling is limited by the driving pipe equipment and geological conditions, and the pile length and diameter cannot meet the large design bearing capacity requirements. Hole-forming methods generally include impact drilling, long and short spiral drilling, forward and reverse circulation drilling, rotary drilling, and manual excavation. Rotary drilling is currently the most commonly used method for constructing large-diameter pile foundations. However, when encountering rock strata, especially hard rock strata, drilling efficiency is very low. In such cases, a staged drilling process is required, which typically involves gradually changing drill bits of different diameters to enlarge the hole step by step, making the hole-forming process cumbersome.

[0003] The staged drilling process not only requires multiple drill bit changes, but also demands that the center point of the hole be consistent before and after each drill bit change. This not only affects drilling efficiency, but also necessitates guiding measures to ensure the coaxiality of pile holes with different diameters, increasing the construction difficulty. Utility Model Content

[0004] The purpose of this invention is to provide a non-grading integrated drill bit to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, this utility model provides the following technical solution:

[0006] A non-grading integrated drill bit includes a mounting shaft. An outer cylinder, a middle cylinder, and a centering drill bit are fixedly mounted on the outer surface of the mounting shaft from top to bottom. The diameters of the outer cylinder, the middle cylinder, and the centering drill bit decrease sequentially. Multiple protrusions are movably mounted on the outer surfaces of the outer cylinder, the middle cylinder, and the centering drill bit. Multiple toothed cones are fixedly mounted below the outer surfaces of the outer cylinder, the middle cylinder, and the centering drill bit.

[0007] Preferably, a hollow groove is provided on the bottom surface of the mounting shaft.

[0008] Preferably, the roller cone consists of a roller cone barrel and a cutting drill bit, with the cutting drill bit embedded in the inner wall of the bottom end of the roller cone barrel.

[0009] Preferably, the outer sides of the cutting teeth are inclined upward or downward, and the inclination directions of two adjacent cutting teeth are opposite.

[0010] Compared with the prior art, this utility model provides a stepless integrated drill bit, which has the following advantages:

[0011] 1. This integrated drill bit, which does not require grading, utilizes a small-diameter straightening bit at the front end to first drill, loosening the circumference of the rock core inside the hole, increasing the free surface of the rock strata, thereby reducing its stress level. This facilitates further drilling by the large-diameter barrel drill, improving its working efficiency. At the same time, it creates a free surface for rock fracturing for the straightening bit in the middle barrel drilling. Similarly, the roller cones on the middle barrel create a free surface for rock fracturing for the outer barrel. This drill bit uses two or more drill bits alternately, which not only provides free surfaces for each other, greatly improving drilling efficiency, but also enhances rock breaking ability.

[0012] 2. This integrated drill bit combines rotary drill bits of different diameters into a single integrated drill bit, enabling efficient drilling of large-diameter rock-socketed piles without the need for grading. Its hollow design reduces the drill bit's weight and soil friction during drilling. The cutting teeth embedded in the roller cones aid in core extraction. This drill bit significantly improves the efficiency of rock strata construction. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the structure of this utility model;

[0014] Figure 2 This is a schematic diagram of the structure of this utility model from another angle;

[0015] Figure 3 for Figure 1 Enlarged view of the structure at point A in the middle.

[0016] In the diagram: 1. Mounting shaft; 2. Outer cylinder; 3. Middle cylinder; 4. Drill bit straightening device; 5. Gear cone; 6. Raised mark; Detailed Implementation

[0017] Please see Figure 1-3 A non-grading integrated drill bit includes a mounting shaft 1, the top end of which is fixedly connected to the drill rod power head for providing power to the device;

[0018] The outer cylinder 2, middle cylinder 3, and centralizing drill bit 4 are fixedly mounted sequentially from top to bottom on the outer surface of the mounting shaft 1. The diameters of the outer cylinder 2, middle cylinder 3, and centralizing drill bit 4 decrease sequentially. The drill bit utilizes the small-diameter centralizing drill bit 4 at the front end to drill first, loosening the circumference of the rock core inside the hole, increasing the free surface of the rock strata, reducing its stress level, and making it easier for the large-diameter cylinder drill to drill further, thus improving its working efficiency. At the same time, it creates a free surface for rock fracturing for the middle cylinder 3 to drill into the centralizing drill bit 4. Similarly, the roller cone 5 on the middle cylinder 3 creates a free surface for rock fracturing for the outer cylinder 2. This drill bit uses two or more drill bits alternately, which not only provides free surfaces for each other, greatly improving drilling efficiency, but also enhances rock breaking ability.

[0019] Multiple protrusions 6 are movably installed on the outer surfaces of the outer cylinder 2, the middle cylinder 3, and the straightening drill bit 4 for drilling directly to the final hole. Multiple roller cones 5 are fixedly installed below the outer surfaces of the outer cylinder 2, the middle cylinder 3, and the straightening drill bit 4 to create a free surface of rock mass fracture, which facilitates subsequent drill bit entry.

[0020] The bottom surface of the mounting shaft 1 is provided with a hollow groove to reduce the weight of the drill bit and the soil friction resistance during drilling.

[0021] Furthermore, the roller cone 5 consists of a roller cone barrel and a cutting tooth drill bit. The cutting tooth drill bit is embedded in the inner wall of the bottom end of the roller cone barrel. The outer sides of the cutting tooth drill bit are inclined upward or downward. The inclination directions of two adjacent cutting tooth drill bits are opposite, which helps to break off the rock core and facilitates the rapid creation of a free surface for rock mass fracture.

[0022] Example

[0023] The drill bit is started by powering the drill rod. Driven by the drill rod and drill rod, the drill bit rotates clockwise. This drill bit consists of a centering drill bit 4, a middle cylinder 3, and an outer cylinder 2. The centering drill bit 4 is a 1.6m diameter roller cone core drill with a 1.6m diameter lower centering device. The middle cylinder 3 is a 2m diameter roller cone core drill with 12 roller cones. The outer cylinder 2 is a 2.5m / 2.8m diameter core drill with 16-18 roller cones. Multiple raised grooves 6 are movably mounted on the outer surfaces of the outer cylinder 2, middle cylinder 3, and centering drill bit 4 for drilling directly to the final hole depth.

[0024] During the drilling process, the small-diameter centering bit 4 at the front end drills first, loosening the circumference of the rock core inside the hole, increasing the free surface of the rock strata, and reducing its stress level. This facilitates further drilling by the large-diameter barrel drill, improving its working efficiency. At the same time, it creates a free surface for rock fracturing for the centering bit 4 to drill into the middle barrel 3. Similarly, the roller cone 5 on the middle barrel 3 creates a free surface for rock fracturing for the outer barrel 2. This drill bit uses two or more bits alternately, which not only provides free surfaces for each other, greatly improving drilling efficiency, but also enhances rock-breaking ability.

[0025] When drilling into rock, if the rock strength is not high, continuous pressure drilling can be carried out. When the rock strength is high, continuous pressure drilling is not effective, causing severe vibration of the drilling rig or the front end of the drilling rig to be significantly lifted. In this case, pulsed pressure should be used to continuously store and release energy in the rock, resulting in leapfrog fracturing.

[0026] The final step involves using a large-diameter drill bit for hole finishing.

[0027] After the borehole is completed, the pile foundation is moved to the next pile location to continue construction.

Claims

1. A non-grading integrated drill bit, comprising a mounting shaft (1), characterized in that: The outer surface of the mounting shaft (1) is fixedly mounted with an outer cylinder (2), a middle cylinder (3) and a straightening drill bit (4) from top to bottom. The diameters of the outer cylinder (2), the middle cylinder (3) and the straightening drill bit (4) decrease in sequence. Multiple protrusions (6) are movably mounted on the outer surfaces of the outer cylinder (2), the middle cylinder (3) and the straightening drill bit (4). Multiple toothed cones (5) are fixedly mounted on the lower part of the outer surfaces of the outer cylinder (2), the middle cylinder (3) and the straightening drill bit (4).

2. The stepless integrated drill bit according to claim 1, characterized in that: The bottom surface of the mounting shaft (1) is provided with a hollow groove.

3. The stepless integrated drill bit according to claim 1, characterized in that: The roller cone (5) is composed of a roller cone cylinder and a cutting tooth drill bit, which is embedded in the inner wall of the bottom end of the roller cone cylinder.

4. The stepless integrated drill bit according to claim 3, characterized in that: The outer sides of the cutting teeth are all inclined upwards or downwards, and the inclination directions of two adjacent cutting teeth are opposite.

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