A composite core drill bit with easily evacuated rock cuttings

Abstract

This utility model discloses a core drill bit composite plate with easy rock cuttings removal, including a core drill bit body and a mounting base mounted thereon. The mounting base is equipped with the core drill bit body. The upper composite plate body also includes a crushing component. The upper crushing component includes a first willow-leaf cutting edge disposed on the surface of the composite plate body. The upper composite plate body also has two second willow-leaf cutting edges, symmetrically arranged on both sides of the first willow-leaf cutting edge. The upper crushing component also includes two inclined blades disposed on the upper surface of the composite plate body, in the lower region. These two inclined blades are symmetrically arranged on the outer sides of the two second willow-leaf cutting edges. This utility model achieves a comprehensive effect of high cutting efficiency, smooth and non-clogging rock cuttings removal, balanced stress and strong durability, and adaptability to complex formations.

Description

Technical Field

[0001] This utility model relates to the field of mining drill bits, specifically a composite core drill bit that facilitates the removal of rock cuttings. Background Technology

[0002] In resource development fields such as geological exploration, oil and gas drilling, and mining, coring bits are the core tools for obtaining underground rock cores (rock samples). Composite sections, as key cutting components of coring bits, directly determine drilling efficiency, core quality, and service life through their structural design. As exploration and development advance into deeper and more complex formations (such as hard formations, formations with well-developed joints and fractures, and formations containing thin interlayers), it is necessary to meet the requirements for cutting and cuttings removal.

[0003] However, the existing core drill bit composite disc crushing component design still has many shortcomings and is difficult to adapt to complex working conditions:

[0004] Disorganized handling of rock cuttings can easily lead to blockages: The cutting edges of existing composite plates are mostly straight, and the rock cuttings generated during cutting tend to spread disorderly on the upper surface of the main body. Some rock cuttings accumulate in the gap between the cutting edge and the main body, which can easily cause blockages at the bottom of the hole. This not only requires stopping the machine for cleaning, but also leads to contamination of the rock core.

[0005] A composite core drill bit with easily evacuated rock cuttings is proposed to address the problems mentioned above. Utility Model Content

[0006] The purpose of this invention is to provide a composite core drill bit that facilitates the removal of rock cuttings, thereby solving the problem of rock cuttings accumulating in the gap between the cutting edge and the main body, which easily causes blockage at the bottom of the hole, requiring not only machine shutdown for cleaning but also contamination of the core.

[0007] To achieve the above objectives, this utility model provides the following technical solution: a core drill bit composite sheet with easy rock cuttings removal, comprising a core drill bit body and a mounting base mounted thereon, wherein the core drill bit body is mounted on the mounting base;

[0008] Also includes:

[0009] The composite sheet body is provided with a crushing component, which includes a first willow leaf cutting edge disposed on the surface of the composite sheet body.

[0010] The composite sheet body is also provided with two second willow leaf cutting edges;

[0011] The two second willow-leaf cutting edges are symmetrically arranged on both sides of the first willow-leaf cutting edge.

[0012] Preferably, the crushing component further includes a beveled blade disposed on the composite sheet body. The beveled blade is disposed on the upper surface of the composite sheet body and in the lower region. There are two beveled blades, which are symmetrically disposed on the outer sides of two second willow leaf cutting edges.

[0013] Preferably, the second willow leaf cutting edge is disposed on the upper surface of the composite sheet body and near the upper region.

[0014] Preferably, the first willow leaf cutting edge is located in the middle and lower part of the upper surface of the composite sheet body.

[0015] Compared with the prior art, the beneficial effects of this utility model are: through the design of the crushing component, it achieves a comprehensive effect of high-efficiency cutting, smooth and non-clogging rock cutting, balanced force and strong durability, and adaptability to complex strata. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of this utility model;

[0017] Figure 2 This is a schematic diagram of the first and second willow-leaf cutting edges in this utility model;

[0018] Figure 3 This is a schematic diagram of the structure of the composite sheet body and the core drill bit body in this utility model.

[0019] In the figure: 1. Composite sheet body; 2. Beveled edge; 3. First willow-leaf cutting edge; 4. Second willow-leaf cutting edge; 5. Mounting base; 6. Core drill bit body. Detailed Implementation

[0020] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0021] Please see Figure 1-3 The present invention provides a technical solution: a core drill bit composite plate with easy rock cuttings removal, including a core drill bit body 6, a mounting base 5 installed on the core drill bit body 6, a composite plate body 1 installed on the core drill bit body 6 through the mounting base 5, and a crushing component provided on the composite plate body 1. The mounting base 5 and the core drill bit body 6 are existing mature technologies, and will not be described in detail in this embodiment. The core solution of this technical solution lies in the specific structure of the crushing component.

[0022] The composite sheet body 1 is cylindrical in shape and is made of high-strength and high-wear-resistant materials, such as a composite structure with diamond as the surface layer and hard alloy as the base.

[0023] Please see Figure 1-2 The crushing component includes a first willow-leaf cutting edge 3 and two second willow-leaf cutting edges 4;

[0024] Wherein: the first willow leaf cutting edge 3 is disposed on the upper surface of the composite sheet body 1, and is located in the lower middle area of ​​the upper surface of the composite sheet body 1.

[0025] Both second willow-leaf cutting edges 4 are set on the upper surface of the composite sheet body 1, and the two second willow-leaf cutting edges 4 are symmetrically distributed on both sides of the first willow-leaf cutting edge 3. At the same time, the second willow-leaf cutting edges 4 are located on the upper surface of the composite sheet body 1 near the upper region, forming a structural distribution that echoes the "lower middle" position of the first willow-leaf cutting edge 3.

[0026] Please see Figure 1-2 The crushing component also includes two inclined blades 2, both of which are set on the upper surface of the composite sheet body 1. The two inclined blades 2 are symmetrically distributed with the center of the upper surface of the composite sheet body 1 as the symmetrical point. The two inclined blades 2 are located on the outside of the two second willow leaf cutting blades 4 respectively. At the same time, the inclination direction of each inclined blade 2 is towards the outside of the composite sheet body 1, forming an outwardly inclined cutting structure.

[0027] During drilling, the first willow-leaf cutting edge 3, acting as the central core cutting edge, first contacts the rock and forms the initial fracture point. Subsequently, the second willow-leaf cutting edges 4 on both sides gradually follow from the periphery towards the center. As the ends of the second willow-leaf cutting edges 4 approach the first willow-leaf cutting edge 3, their cutting edges can form a "seamless connection" with the fracture area of ​​the first willow-leaf cutting edge 3, avoiding the formation of fracture gaps. This collaborative method can transform the rock fracture process from "single fracture" to "central breakthrough and gradual wrapping fracture from both sides." This not only makes the fracture range more coherent but also gradually transfers the rock fracture stress to the center through the gradual cutting of the arc-shaped cutting edge, reducing local stress abrupt changes and lowering the probability of "collapse fracture" caused by excessive instantaneous stress. This improves the uniformity of fracture and is especially suitable for brittle rock formations.

[0028] Please see Figure 1-2 Furthermore, the second willow-leaf cutting edge 4 is designed with an arc shape, meaning that the two second willow-leaf cutting edges 4 together form a smooth arc, such as... Figure 1 and 2As shown in the figure, it can be clearly observed from the appearance that both ends of the two second willow-leaf cutting edges 4 are "gradually approaching the first willow-leaf cutting edge 3", and finally forming an overall cutting structure on the composite sheet body 1 with "the first willow-leaf cutting edge 3 in the middle as the core, and the second willow-leaf cutting edges 4 on both sides arc-shaped and converging towards the first willow-leaf cutting edge 3".

[0029] The design of the second willow-leaf cutting edge 4, with both ends converging towards the first willow-leaf cutting edge 3, further optimizes the transmission path of cutting force. When the second willow-leaf cutting edge 4 cuts rock, the arc-shaped cutting edge can evenly distribute the cutting force along the arc trajectory, avoiding force concentration at a single point on the cutting edge. At the same time, the shape of both ends converging towards the first willow-leaf cutting edge 3 allows part of the cutting force borne by the second willow-leaf cutting edge 4 to be transmitted to the first willow-leaf cutting edge 3 in the middle, forming a force-bearing mode of "the second willow-leaf cutting edge 4 and the first willow-leaf cutting edge 3 sharing the load," rather than the second willow-leaf cutting edge 4 bearing the load on one side alone. This force transmission method can significantly reduce the local stress concentration at the cutting edge of the second willow-leaf cutting edge 4, reducing the risk of edge breakage and premature wear due to excessive stress, while also reducing the individual load-bearing pressure on the first willow-leaf cutting edge 3, extending the overall service life of all three.

[0030] During drilling, the rock cuttings generated by the arc-shaped cutting edge of the second willow-leaf cutting edge 4 slide inward along the trajectory of the arc-shaped cutting edge towards the first willow-leaf cutting edge 3. As the two ends of the second willow-leaf cutting edge 4 move closer to the first willow-leaf cutting edge 3, the rock cuttings eventually form a "concentrated convergence zone" near the first willow-leaf cutting edge 3. This convergence effect prevents the rock cuttings from spreading and accumulating disorderly on the surface of the composite section. On the other hand, it allows the rock cuttings to enter the secondary crushing range of the subsequent inclined cutting edge 2 more concentratedly, making it easier for the inclined cutting edge 2 to uniformly refine and crush the concentrated rock cuttings, and then discharge them in an orderly manner. This reduces the probability of rock cuttings mixing into the core sampling channel and ensures the integrity and quality of the core.

[0031] The two inclined blades 2 respectively crush the rock fragments from both sides of the composite sheet body 1, which can uniformly crush the rock fragments into fine particles and avoid the accumulation of rock fragments on one side.

[0032] In the above:

[0033] The necessity of setting two beveled edges 2 and the limitations of a single beveled edge 2:

[0034] Uneven cutting forces can easily lead to composite disc misalignment: the single-bevel cutting edge 2 cuts outward from only one side of the composite disc body 1, causing the composite disc to bear a concentrated cutting reaction force on one side during operation, thus disrupting the overall force balance. This imbalance can cause the composite disc to tend to deviate to one side during drilling, which not only affects the drilling trajectory accuracy of the core drill bit but may also cause excessive local wear of the composite disc, shortening its service life.

[0035] Insufficient centering and impact resistance: When the single-sloping cutting edge 2 contacts the rock, it can only provide auxiliary centering reaction force from one side, which is insufficient to resist the impact from uneven formation hardness or fractures. This will cause the composite section to shake more during drilling, which will not only affect the core sampling accuracy, but may also cause the main body 1 of the composite section to break due to excessive instantaneous impact.

[0036] Advantages of two beveled cutting edges 2 compared to one beveled cutting edge 2:

[0037] The two symmetrically arranged beveled edges 2 can improve the performance of the composite sheet in many aspects, such as force balance, cuttings handling, and centering stability. The specific advantages are as follows:

[0038] Achieving cutting force balance and reducing offset and wear: The two beveled cutting edges 2 are symmetrically distributed and tilted outwards. During cutting, they simultaneously bear uniform cutting reaction forces from both sides of the composite sheet body 1, forming a balanced force state that cancels each other out. This balance can effectively prevent the offset of the composite sheet body 1 caused by unilateral force, ensuring accurate drilling trajectory. At the same time, uniform force can also reduce local stress concentration in the composite sheet, reduce the risk of excessive wear, and extend the service life of the composite sheet.

[0039] The two inclined cutting edges 2 provide a two-way guiding channel for the cuttings, guiding them out in an orderly manner, greatly improving the smoothness of cuttings removal, reducing the risk of blockage, and thus improving drilling efficiency.

[0040] When the two symmetrically arranged inclined cutting edges 2 come into contact with the rock, they simultaneously provide auxiliary centering reaction forces from both sides, forming a "bidirectional centering" effect. This effect can effectively resist the impact of uneven formation hardness or fractures, reduce the shaking of the composite sheet body 1 during drilling, ensure core sampling accuracy, and at the same time, the bidirectional force can also disperse the impact load, reduce the probability of the composite sheet body 1 cracking due to excessive instantaneous impact, and improve its impact resistance.

[0041] In complex formations containing thin interlayers and well-developed joints and fractures, the two inclined cutting edges 2 can simultaneously cut into the interlayers from both sides or expand the fracturing range by utilizing the fractures. This avoids the "uneven wear" problem caused by uneven formation when the single inclined cutting edge 2 cuts on one side, allowing the composite piece to better adapt to different types of complex formations and improve the overall drilling adaptability.

[0042] The necessity of setting two second willow-leaf cutting edges 4 and the limitations of a single second willow-leaf cutting edge 4:

[0043] Considering the cutting coordination requirements and formation fracturing efficiency during core drilling, setting only one second willow-leaf cutting edge 4 results in incomplete cutting coverage and low formation fracturing efficiency. The first willow-leaf cutting edge 3 is located in the lower middle of the upper surface of the composite sheet body 1. If only one second willow-leaf cutting edge 4 is set on one side, the cutting area on the upper surface of the composite sheet will exhibit a "one-sided coverage, one-sided gap" state. During drilling, the rock on the gap side cannot be fracturing in time, which not only prolongs the single cutting cycle but also increases cutting resistance due to the unfractured rock, thus reducing the overall formation fracturing efficiency.

[0044] The first willow-leaf cutting edge 3 and the second willow-leaf cutting edge 4 can only form a "one-sided cooperation". During cutting, the force on both is concentrated on one side of the composite sheet body 1, while the other side lacks cutting force support, resulting in an overall force imbalance of the composite sheet. This imbalance will cause the first willow-leaf cutting edge 3 and the second willow-leaf cutting edge 4 to bear additional off-center loads, accelerating local wear and shortening the effective working life of the cutting edges.

[0045] The core advantages of two second willow-leaf cutting edges 4 compared to one second willow-leaf cutting edge 4 are:

[0046] It can significantly improve the performance of composite sheets from the dimensions of cutting coordination, stress balance, and rock cuttings processing;

[0047] Two second willow-leaf cutting edges 4 form symmetrical cutting areas on both sides of the first willow-leaf cutting edge 3, which, in conjunction with the "lower-middle" position of the second willow-leaf cutting edge 4, cover most of the effective cutting range on the upper surface of the composite sheet body 1. During drilling, the rock in different areas is efficiently broken, avoiding cutting gaps, significantly shortening the single cutting cycle, and improving the overall formation breaking efficiency, which is especially suitable for hard formations or scenarios requiring rapid drilling.

[0048] Two second willow-leaf cutting edges 4 are symmetrically distributed, forming a "triangular cooperative force-bearing" structure with the first willow-leaf cutting edge 3. During cutting, the cutting force borne by all three is evenly distributed on the composite sheet body 1, avoiding unilateral force imbalance. At the same time, the two second willow-leaf cutting edges 4 can share part of the load of the first willow-leaf cutting edge 3, reducing the stress intensity of a single cutting edge, reducing excessive local wear, extending the service life of all cutting edges, and reducing the frequency and cost of replacing the composite sheet.

[0049] Two second willow-leaf cutting edges 4 generate rock chips on both sides of the first willow-leaf cutting edge 3, forming a "bidirectional dispersion" distribution with the rock chips generated by the first willow-leaf cutting edge 3, avoiding rock chip accumulation on one side. At the same time, the rock chips generated by the three can diffuse outward along the symmetrical direction of the upper surface of the composite sheet body 1, providing a smoother bidirectional discharge channel for the rock chips, reducing the risk of blockage, and the uniformly generated rock chip particles are more consistent in size, which facilitates secondary crushing by the subsequent inclined cutting edge 2, further improving the rock chip discharge efficiency and ensuring the integrity and accuracy of the core sample.

[0050] In complex formations containing thin interlayers and joints, the two second willow-leaf cutting edges 4 can work in tandem with the first willow-leaf cutting edge 3 to create a "multi-edge collaborative response." When encountering interlayers or fractures, all three can cut in from different positions, avoiding "uneven wear" caused by a single second willow-leaf cutting edge 4 contacting abnormal formations on one side. At the same time, the symmetrically distributed structure enhances the composite section's resistance to shaking during drilling, reduces drilling deviation caused by uneven formations, and ensures accurate core sampling trajectory.

[0051] Design of the shape of the second willow-leaf cutting edge 4:

[0052] The symmetrical arc design of the two second willow-leaf cutting edges 4 better adapts to the rock texture. The arc-shaped cutting edge can cut along the curve of the rock texture, avoiding the "hard cutting resistance" caused by the straight cutting edge being perpendicular to the texture. At the same time, the two ends of the second willow-leaf cutting edge 4 move closer to the first willow-leaf cutting edge 3, making the contact process between the cutting edge and the rock more "gradual". From the outer arc of the second willow-leaf cutting edge 4 to the inner side near the first willow-leaf cutting edge 3, the contact area between the cutting edge and the rock gradually transitions, rather than suddenly increasing. This "gradual contact" can significantly reduce the impact resistance during the initial cutting, making the drilling process smoother, reducing the shaking of the composite blade caused by sudden changes in resistance, and further improving drilling stability.

[0053] In summary, this utility model:

[0054] Highly efficient cutting without blind spots: The layout of the first willow-leaf cutting edge 3 and the second willow-leaf cutting edge 4 covers the main cutting area on the upper surface of the composite sheet body 1, eliminating the "cutting blind spot". Combined with the design of the second willow-leaf cutting edge 4, it forms a "center breakthrough and two-sided wrapping and breaking" mode with the first willow-leaf cutting edge 3, realizing continuous and seamless breaking, shortening the cutting cycle, and significantly improving drilling efficiency in hard and brittle formations.

[0055] Smooth rock cuttings handling: The first willow-leaf cutting edge 3 and the two second willow-leaf cutting edges 4 generate uniform rock cuttings. The arc-shaped structure of the second willow-leaf cutting edge 4 guides the rock cuttings to converge towards the first willow-leaf cutting edge 3. The inclined edge 2 further breaks the rock cuttings and provides bidirectional guidance, forming a chain of "generation, convergence, refinement, and discharge", avoiding blockage at the bottom of the hole and ensuring continuous drilling.

[0056] Force balance and wear resistance: The second willow-leaf cutting edge 4 and the first willow-leaf cutting edge 3 form a "triangular force distribution", which evenly distributes the cutting force; the two beveled edges 2 symmetrically cancel the reaction force, eliminating unilateral stress. The second willow-leaf cutting edge 4 can also transfer the force to the first willow-leaf cutting edge 3. Multi-dimensional optimization reduces the damage to the cutting edges of the beveled edges 2, the first willow-leaf cutting edge 3, and the second willow-leaf cutting edge 4, and extends the overall life of the composite sheet body 1.

[0057] Wide impact resistance and adaptability: The design of two beveled cutting edges 2 and two second willow-leaf cutting edges 4 provides bidirectional resistance to formation impact and reduces swaying and deviation; it also reduces initial cutting resistance, avoids instantaneous damage to the composite sheet body 1, and is suitable for complex formations such as fractures and interlayers, reducing the need for replacement due to failure.

[0058] To ensure core quality: the second willow-leaf cutting edge 4 guides rock cuttings to concentrate on the first willow-leaf cutting edge 3, and the inclined edge 2 assists in the orderly discharge of rock cuttings, reducing the amount of rock cuttings mixed into the core sampling channel and improving the integrity of the rock core.

[0059] Wide range of applications: Through the collaboration of "first willow-leaf cutting edge 3, second willow-leaf cutting edge 4, and inclined edge 2", it is suitable for various strata such as soft soil, sandstone to granite, and can be used in geological exploration, oil and gas drilling, mining and other scenarios.

[0060] In summary, the design of the crushing components achieves a comprehensive effect of high-efficiency cutting, smooth and non-clogging rock cuttings handling, balanced stress and strong durability, and adaptability to complex strata.

[0061] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A core drill bit composite sheet with easy rock cuttings removal, comprising a core drill bit body (6) and a mounting base (5) mounted thereon, wherein the core drill bit body (6) is mounted on the mounting base (5); characterized in that Also includes: A crushing component is provided on the composite sheet body (1), and the crushing component includes a first willow leaf cutting edge (3) provided on the surface of the composite sheet body (1); The composite sheet body (1) is also provided with two second willow leaf cutting edges (4); Two second willow leaf cutting edges (4) are symmetrically arranged on both sides of the first willow leaf cutting edge (3).

2. The core bit insert of claim 1, wherein: The crushing component also includes a beveled blade (2) disposed on the composite sheet body (1), the beveled blade (2) being disposed on the upper surface and lower part of the composite sheet body (1).

3. The core bit insert of claim 1, wherein: The second willow leaf cutting edge (4) is disposed on the upper surface of the composite sheet body (1) and near the upper region.

4. The core bit insert of claim 1, wherein: The first willow leaf cutting edge (3) is located in the middle and lower part of the upper surface of the composite sheet body (1).

5. The core bit insert of claim 2, wherein: The number of the beveled blades (2) is two.

6. The core bit insert of claim 2, wherein: The two beveled cutting edges (2) are symmetrically arranged on the outside of the two second willow leaf cutting edges (4).

Images