Diamond bit of self-sharpening structure

Abstract

The utility model provides a diamond drill bit of self-sharpening structure, including drill steel body and the multiple drill bit working body of fixed connection in the end of drill steel body, drill bit working body includes main working body and inserts in the vice working body of main working body, the wear resistance of vice working body is lower than the wear resistance of main working body, main working body and vice working body are all arranged as the fan shape concentric with drill steel body on the radial section of drill bit, the volume concentration of first abrasive in main working body is greater than the volume concentration of second abrasive in vice working body. Through setting up main working body wear resistance is higher than vice working body, vice working body preferentially wears in drilling, and its abrasive is easier to sharpen, improves drilling efficiency, vice working body wears earlier than main working body, thereby forms the regular groove on the drill bit lip surface, realizes the sharpening to drill bit lip surface.

Description

Technical Field

[0001] This utility model relates to the field of geological exploration and drilling engineering, and in particular to a self-sharpening diamond drill bit. Background Technology

[0002] my country's geological exploration, scientific drilling, deep mineral exploration, and geothermal and other new energy exploration have developed rapidly. As a result, the rock strata encountered during drilling are diverse and the lithology varies greatly. While vigorously promoting wireline coring drilling technology, it is necessary to have diamond drill bits with high efficiency, long service life, and good adaptability to rock strata to match it. Otherwise, the advantages of modern deep wireline coring drilling cannot be brought into play, which will inevitably lead to a situation where the construction period is greatly extended and the drilling cost is significantly increased.

[0003] However, conventional hot-pressed diamond drill bits have always suffered from unsatisfactory adaptability to rock formations. Changes in the rock strata encountered inevitably lead to significant changes in drilling time. Existing drill bits have poor self-sharpening properties, slow cutting edge emergence, and can even result in drilling failures. Drilling sites must prepare drill bits with various performance characteristics for easy replacement, causing numerous problems and significantly increasing drilling costs. The main reason for this is the significant performance limitations of conventional drill bits and their poor adaptability to rock formations. These problems have plagued drilling engineers for many years and have not been well resolved, becoming an urgent research and development topic in the field of geological engineering. Utility Model Content

[0004] This invention provides a self-sharpening diamond drill bit to solve the problems of poor self-sharpening performance and slow cutting speed of existing diamond drill bits.

[0005] This utility model provides a self-sharpening diamond drill bit, including a drill bit body and a plurality of drill bit working bodies fixedly connected to the end of the drill bit body. The drill bit working bodies are distributed circumferentially along the drill bit body, and a water gate is provided between two adjacent drill bit working bodies. Each drill bit working body includes a main working body and a secondary working body embedded in the main working body. The secondary working body is completely enclosed by the main working body. The main working body includes a first matrix and a first abrasive distributed in the first matrix. The secondary working body includes a second matrix and a second abrasive distributed in the second matrix. The wear resistance of the secondary working body is lower than that of the main working body. Both the main working body and the secondary working body are fan-shaped in the radial cross-section of the drill bit.

[0006] Furthermore, the wear rate ML of the main working body is 0.58 × 10⁻⁶. -5 ~0.72×10 -5 The hardness of the first tire carcass is set to HRC15 to HRC25.

[0007] Furthermore, the wear rate ML of the auxiliary working body is 0.88 × 10⁻⁶. -5 ~1.0×10 -5 The hardness of the second tire carcass is set to HRC6 to HRC10.

[0008] Furthermore, the water inlet is set in a trapezoidal shape on the radial section of the drill bit, and the maximum width of the water inlet is set to 5 mm to 10 mm.

[0009] Furthermore, the auxiliary working body is arranged in multiple layers at radial intervals along the drill bit steel body.

[0010] Furthermore, the radial width of the auxiliary working body is 1.5 mm to 3.5 mm, and the arc length of the auxiliary working body is 5.0 mm to 9.0 mm.

[0011] Furthermore, the radial width of the auxiliary working body increases along the direction close to the drill bit steel body.

[0012] Furthermore, the auxiliary working bodies are arranged in two layers radially, with 1 to 3 auxiliary working bodies in the outer layer and 1 to 2 auxiliary working bodies in the inner layer. The auxiliary working bodies in the same layer are arranged circumferentially along the drill bit.

[0013] Furthermore, the auxiliary working bodies are arranged in three layers radially, with 2 to 3 auxiliary working bodies in the outer layer, 1 to 2 auxiliary working bodies in the middle layer, and 1 to 2 auxiliary working bodies in the inner layer. The auxiliary working bodies in the same layer are arranged circumferentially along the drill bit.

[0014] Furthermore, the cross-sectional area of ​​the auxiliary working body accounts for 20% to 28% of the cross-sectional area of ​​the drill bit working body.

[0015] The beneficial effects provided by this utility model are as follows:

[0016] 1. By setting the wear resistance of the main working body to be higher than that of the secondary working body, the secondary working body wears out first during drilling, making it easier for the abrasive to break through the cutting edge and improving drilling efficiency. At the same time, the secondary working body is set as a fan-shaped structure concentric with the drill bit body. The secondary working body wears out before the main working body, thus forming regular grooves on the drill bit lip surface, achieving sharpening of the drill bit lip surface. The width of the groove is basically equal to the radial width of the secondary working body. The degree of sharpening of the drill bit lip surface during operation can be adjusted by adjusting the radial width of the secondary working body.

[0017] 2. The drill bit working body is designed so that the main working body completely encloses the auxiliary working body. The abrasive material that falls off from the auxiliary working body will wear down the matrix of the main working body, which is beneficial for the diamond in the main working body to emerge from the cutting edge and improve drilling efficiency.

[0018] 3. The wear rate ML of the main working body is 0.58 × 10⁻⁶. -5 ~0.72×10 -5 The hardness of the first matrix is ​​set to HRC15 to HRC25, which is beneficial for the effective setting of diamonds and promotes the self-grinding of diamonds, thereby improving the adaptability of the drill bit to rock formations, increasing drilling efficiency and the service life of the drill bit.

[0019] 4. The wear rate ML of the auxiliary working body is 0.88 × 10⁻⁶. -5 ~1.0×10 -5 The hardness of the second matrix is ​​set to HRC6 to HRC10, which is beneficial to the wear of the second matrix, making it easier for the diamond and silicon carbide abrasives in the second matrix to develop cutting edges, and also reduces drilling pressure consumption, ensuring the drilling pressure of the main working body, thereby improving the overall drilling efficiency of the drill bit and ensuring the universality of the drill bit of this invention.

[0020] 5. By setting the cross-sectional area of ​​the secondary working body to account for 20%–28% of the cross-sectional area of ​​the drill bit's working body, and considering that the second working body is softer and more easily worn than the first, limiting the cross-sectional area of ​​the secondary working body further reduces the pressure on the drill bit during drilling. This allows most of the pressure on the drill bit to be used on the main working body, increasing the drilling pressure ratio, which is beneficial for diamond cutting edge engagement and increasing drilling speed. The combined effect improves the drill bit's versatility, effectively balancing high drilling efficiency and long drill bit life. Simultaneously, the abrasive within the secondary working body, after breaking the rock, is more easily detached from the second working body. The remaining abrasive, still capable of working, will generate friction and wear on the first working body as the drill bit rotates, further facilitating diamond cutting edge engagement in the main working body and thus increasing drilling speed. The combined effect of increased drilling pressure ratio and improved diamond cutting edge engagement in the main working body enhances the drill bit's drilling performance and adaptability to different rock types. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the present invention.

[0022] Figure 2 This is the present invention. Figure 1 Sectional view along line A-A.

[0023] Figure 3 This is a schematic diagram of the structure of Embodiment 2 of the present invention.

[0024] Figure 4 This is the present invention. Figure 3 Sectional view along line B-B.

[0025] Figure label:

[0026] 1. Main working body; 2. First abrasive; 3. First matrix; 4. Secondary working body; 5. Second abrasive; 6. Second matrix; 7. Sprue; 8. Drill bit steel body. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0028] The terms "first" and "second" in the specification and claims of this utility model may explicitly or implicitly include one or more of the features. In the description of this utility model, unless otherwise stated, "multiple" means two or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0029] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0030] The following is combined Figures 1-4This invention describes a self-sharpening diamond drill bit, comprising a drill bit body 8 and a plurality of drill bit working bodies fixedly connected to the end of the drill bit body 8. The drill bit working bodies are distributed circumferentially along the drill bit body 8, and a water inlet 7 is provided between adjacent drill bit working bodies. Each drill bit working body includes a main working body 1 and a secondary working body 4 embedded in the main working body 1. The secondary working body 4 is completely enclosed by the main working body 1. The main working body 1 includes a first matrix 3 and a first abrasive 2 distributed within the first matrix 3. The secondary working body 4 includes a second matrix 6 and a second abrasive 5 distributed within the second matrix 6. The wear resistance of the secondary working body 4 is lower than that of the main working body 1. Both the main working body 1 and the secondary working body 4 are fan-shaped in the radial cross-section of the drill bit.

[0031] Specifically, such as Figure 1 As shown, this application embeds a fan-shaped secondary working body 4 within a fan-shaped main working body 1. Simultaneously, by setting the wear resistance of the main working body 1 to be higher than that of the secondary working body 4, the secondary working body 4 wears preferentially during drilling, making it easier for its abrasive to develop and improving drilling efficiency. Furthermore, the secondary working body 4 is configured as a fan-shaped structure concentric with the drill bit steel body 8. The secondary working body 4 wears before the main working body 1, thus forming regular grooves on the drill bit lip surface, achieving sharpening of the drill bit lip surface. The width of the grooves is approximately equal to the radial width of the secondary working body 4, and the degree of sharpening of the drill bit lip surface during operation can be adjusted by regulating the radial width of the secondary working body 4.

[0032] Furthermore, the wear rate ML of the main working body 1 is 0.58 × 10⁻⁶. -5 ~0.72×10 -5 The hardness of the first tire body 3 is set to HRC15 to HRC25.

[0033] Specifically, the wear rate ML is an indicator reflecting the wear resistance of a material (see DZ / T 0366-2021 Geological Core Drilling Diamond Drill Bit Testing Specification). The higher the value, the lower the wear resistance, and vice versa. Specifically, the first abrasive 2 includes diamond. By setting the overall wear resistance of the main working body 1 and the hardness of the first matrix 3, it is beneficial to effectively embed the diamond and also to facilitate the self-grinding of the diamond, thereby improving the adaptability of the drill bit of this invention to rock formations, increasing drilling efficiency, and extending the service life of the drill bit.

[0034] Furthermore, the wear rate ML of the secondary working body 4 is 0.88 × 10⁻⁶. -5 ~1.0×10 -5 The hardness of the second tire body 6 is set to HRC6 to HRC10.

[0035] Specifically, the second abrasive 5 includes diamond and silicon carbide. By setting the overall wear resistance of the auxiliary working body 4 and the hardness of the second matrix 6, it is beneficial to the wear of its matrix, and the diamond and silicon carbide abrasives are easy to cut. It also reduces the drilling pressure consumption, ensures the drilling pressure of the main working layer, so as to improve the overall drilling efficiency of the drill bit and ensure the universality of the drill bit of the present invention.

[0036] Furthermore, the water inlet 7 is set as a trapezoid in the radial section of the drill bit, and the maximum width of the water inlet 7 is set to 5 mm to 10 mm.

[0037] Furthermore, the auxiliary working body 4 is arranged in multiple layers at radial intervals along the drill bit steel body 8.

[0038] Furthermore, the radial width of the secondary working body 4 is 1.5 mm to 3.5 mm, and the arc length of the secondary working body 4 is 5.0 mm to 9.0 mm.

[0039] Furthermore, the radial width of the auxiliary working body 4 increases along the direction close to the drill bit steel body 8.

[0040] Specifically, such as Figure 2 As shown, the radial width of the auxiliary working body 4 is set to increase along the direction close to the drill bit steel body 8, and the axial cross-section of the auxiliary working body 4 is a trapezoidal structure. This allows the area of ​​the auxiliary working body 4 to gradually increase while the area of ​​the main working body 1 decreases as the drilling depth increases and the drill bit lip wears down, thereby increasing the drilling pressure of the main working body 1 and enhancing drilling efficiency.

[0041] Furthermore, the cross-sectional area of ​​the auxiliary working body 4 accounts for 20% to 28% of the cross-sectional area of ​​the drill bit working body.

[0042] Specifically, by setting the cross-sectional area of ​​the auxiliary working body 4 to account for 20%–28% of the cross-sectional area of ​​the drill bit's working body, and considering that the second matrix 6 is softer and more easily worn than the first matrix 3, limiting the cross-sectional area of ​​the auxiliary working body 4 further reduces the pressure on the drill bit during drilling. This allows most of the pressure on the drill bit to be used on the main working body 1, increasing the drilling pressure ratio, which is beneficial for diamond cutting edge engagement and increasing drilling speed. The combined effect improves the drill bit's versatility, effectively balancing high drilling efficiency and long drill bit life. Simultaneously, the abrasive within the auxiliary working body 4, after breaking the rock, is more easily detached from the second matrix 6. The remaining abrasive, still capable of working, will generate friction and wear on the first matrix 3 as the drill bit rotates, further facilitating diamond cutting edge engagement within the main working body 1 and thus increasing drilling speed. The combined effect of increased drilling pressure ratio and improved diamond cutting edge engagement within the main working body 1 enhances the drill bit's drilling performance and its adaptability to different rock types.

[0043] In one optional embodiment, the auxiliary working bodies 4 are arranged in two layers along the radial direction. The number of auxiliary working bodies 4 in the outer layer is set to 1 to 3, and the number of auxiliary working bodies 4 in the inner layer is set to 1 to 2. The auxiliary working bodies 4 in the same layer are arranged along the circumference of the drill bit.

[0044] In one specific embodiment, the auxiliary working bodies 4 are arranged in three layers radially. The number of auxiliary working bodies 4 in the outer layer is set to 2 to 3, the number of auxiliary working bodies 4 in the middle layer is set to 1 to 2, and the number of auxiliary working bodies 4 in the inner layer is set to 1 to 2. The auxiliary working bodies 4 in the same layer are arranged circumferentially along the drill bit.

[0045] The technical solutions provided in this application will be described in detail below with reference to the embodiments.

[0046] Example 1

[0047] like Figure 1 , Figure 2 As shown, taking a 95 / 64mm diameter wireline coring drill bit as an example, according to the rock properties and the specifications of the drill bit of this invention, the drill bit is equipped with 10 fan-shaped main working bodies 1 and 10 trapezoidal water inlets 7, with the outer diameter of the trapezoidal water inlets 7 being 7mm wide.

[0048] The drill bit features a self-sharpening sub-working body 4: Two layers of sub-working bodies 4 are arranged radially along the drill bit within each main working body 1. Within the same main working body 1, the inner layer has one sub-working body 4, and the outer layer has two. The fan-shaped sub-working bodies 4 in the same layer are distributed in a ring shape. The radial width of the top of the sub-working body 4 in the outer ring is 3.0 mm, the radial width of the bottom is 3.2 mm, and the outer arc length of the top is 7.0 mm. The radial width of the top of the sub-working body 4 in the inner ring is 3.0 mm, the radial width of the bottom is 3.2 mm, and the outer arc length of the top is 8.0 mm. The distance between the top of the sub-working body 4 in the outer ring and the outer diameter of the drill bit is 3.5 mm, the distance between the top of the sub-working body 4 in the inner ring and the inner diameter of the drill bit is 3.0 mm, and the distance between the top of the sub-working body 4 in the outer ring and the top of the sub-working body 4 in the inner ring is 3.0 mm. The radial width of the sub-working body 4 increases along the direction closer to the drill bit body 8, and the axial cross-section of the sub-working body 4 is trapezoidal.

[0049] The mechanical properties of the drill bit's main working body 1 are as follows: the hardness of the first matrix 3 is HRC16, and the overall wear rate ML of the main working body 1 is 0.70 × 10⁻⁶. -5 The design performance of the secondary working body 4 is as follows: the hardness of the second body 6 is HRC8, and the overall wear rate ML of the secondary working body 4 is 0.86 × 10⁻⁶. -5 .

[0050] To achieve the performance of the main working body 1 of the drill bit, the first matrix 3 is composed of the following materials: Fe-Cu-Ni, Fe-Cu-Mn, FJT-A2, FJT-A3, YG8 and 660-Cu pre-alloy powder, with weight ratios of 24%, 11%, 20%, 23%, 12% and 10%, respectively.

[0051] To achieve the performance of the drill bit auxiliary working body 4, the second body 6 is composed of the following materials: FJT-A2 and Fe-Cu-Ni pre-alloyed powder, with a weight ratio of 82% and 18%, respectively.

[0052] The diamond parameters in the main working body 1 of the drill bit are as follows: diamond volume concentration 92%; 55% of the diamonds are 30-40 mesh by volume, and 45% are 50-60 mesh; diamond type MBD40.

[0053] The abrasive in drill bit workpiece 4 is diamond and silicon carbide, with the following parameters:

[0054] Diamond, volume concentration 25%, particle size 40 mesh, model SMD8;

[0055] Silicon carbide, volume concentration 40%, particle size 40 mesh.

[0056] The method for preparing a self-sharpening diamond drill bit includes the following steps:

[0057] Step S1: The raw materials of the first matrix 3 and the first abrasive 2 are mixed to prepare the raw material of the main working body 1;

[0058] The raw materials for the secondary working body 4 are prepared by mixing the raw materials of the second matrix 6 and the second abrasive 5.

[0059] Step S2: Create a three-dimensional model of the drill bit of the present invention on a computer, then convert the three-dimensional model into STL format and import it into the control software of the laser selective sintering equipment.

[0060] Step S3: The two prepared matrix mixtures are respectively fed into the powder feeding device of the laser selective sintering equipment, and the forming cavity is evacuated.

[0061] Step S4: Then, argon gas is introduced into the above-mentioned molding cavity;

[0062] Step S5: Using the drill bit steel body 8 as a substrate, fan-shaped main working body 1 and auxiliary working body 4 are formed on the drill bit steel body 8 using an SLS printing device until the entire working layer height of the drill bit of the present invention is formed. The laser selective sintering (SLM) forming parameters are: laser power 250W, scanning speed 720mm / s, scanning spacing 0.12mm, powder thickness 0.22mm, spot diameter 0.10mm, and the scanning method is a comprehensive scanning method: that is, a combination of scanning in the short side direction and scanning in the opposite side of the long side; the substrate for the SLS forming molten pool is not set separately, but is replaced by the drill bit steel body 8, and its preheating temperature is 320℃.

[0063] Step S6: After the drill bit of the present invention is formed, it is removed and subjected to stress-relieving annealing treatment; the annealing temperature is 380℃ and the time is 3.5h to promote the healing of microcracks and eliminate structural defects. After cooling, it is machined and decorated.

[0064] Example 2

[0065] like Figure 3 , Figure 4 As shown, taking a 77 / 48mm diameter wireline coring drill bit as an example, based on the rock properties and the requirements of the drill bit of this invention, the drill bit is equipped with 8 fan-shaped main working bodies 1 and 8 water inlets 7, with the trapezoidal water inlets 7 having an outer diameter width of 8mm.

[0066] The drill bit features a self-sharpening structure with two layers of auxiliary working bodies 4 arranged radially along the drill bit within each main working body 1. Within the same main working body 1, there is one auxiliary working body 4 in the inner layer and one in the outer layer. The fan-shaped auxiliary working bodies 4 in the same layer are distributed in a ring shape. The auxiliary working bodies 4 in the outer ring have a top radial width of 2.5 mm, a bottom radial width of 2.6 mm, and a top outer arc length of 9.0 mm. The auxiliary working bodies 4 in the inner ring have a top radial width of 2.5 mm, a bottom radial width of 2.6 mm, and a top outer arc length of 6.0 mm. The distance between the top of the auxiliary working bodies 4 in the outer ring and the top of the auxiliary working bodies 4 in the inner ring is 3.0 mm. The distance between the top of the auxiliary working bodies 4 in the outer ring and the outer diameter of the drill bit is 3.5 mm, and the distance between the top of the auxiliary working bodies 4 in the inner ring and the inner diameter of the drill bit is 3.0 mm.

[0067] The mechanical properties of the main working body 1 of the drill bit are as follows: the hardness of the first matrix 3 is HRC18, and the overall wear rate ML of the main working body 1 is 0.68 × 10⁻⁶. -5 The mechanical properties of the sub-working body 4 are as follows: the hardness of the second body 6 is HRC7, and the overall wear rate ML of the sub-working body 4 is 0.81×10⁻⁶. -5 .

[0068] To achieve the performance of the main working body 1 of the drill bit, the first matrix 3 is composed of the following materials: Fe-Cu-Ni, Fe-Cu-Mn, FJT-A2, FJT-A3, YG8 and 660-Cu pre-alloy powder, with weight ratios of 27%, 10%, 18%, 22%, 14% and 9%, respectively.

[0069] To achieve the performance of the drill bit auxiliary working body 4, the second body 6 is composed of the following materials: FJT-A2 and Fe-Cu-Ni pre-alloyed powder, with a weight ratio of 80% and 20%, respectively.

[0070] The diamond parameters in the main working body 1 of the drill bit are as follows: diamond volume concentration 86%; 60% of the diamonds are 35-40 mesh by volume, and 40% are 50-60 mesh; diamond type MBD40.

[0071] The abrasive in drill bit workpiece 4 is diamond and silicon carbide, with the following parameters:

[0072] Diamond, volume concentration 30%, particle size 40-45 mesh, model SMD8;

[0073] Silicon carbide, volume concentration 25%, particle size 40 mesh.

[0074] The method for preparing a self-sharpening diamond drill bit includes the following steps:

[0075] Step S1: The raw materials of the first matrix 3 and the first abrasive 2 are mixed to prepare the raw material of the main working body 1;

[0076] Step S2: Create a three-dimensional model of the drill bit of the present invention on a computer, then convert the three-dimensional model into STL format and import it into the control software of the laser selective sintering equipment.

[0077] Step S3: The two prepared matrix mixtures are respectively fed into the powder feeding device of the laser selective sintering equipment, and the forming cavity is evacuated.

[0078] Step S4: Then, argon gas is introduced into the above-mentioned molding cavity;

[0079] Step S5: Using the drill bit steel body 8 as a substrate, the fan-shaped main working body 1 and auxiliary working body 4 are formed on the drill bit steel body 8 using an SLS printing device until the entire working layer height of the drill bit of the present invention is formed. The laser selective sintering (SLM) forming parameters are: laser power 240W, scanning speed 500mm / s, scanning spacing 0.15mm, powder thickness 0.20mm, and a comprehensive scanning method is adopted: that is, a combination of scanning in the short side direction and scanning in the opposite side of the long side; the substrate for the SLM forming molten pool is not set separately, but is replaced by the drill bit steel body 8, and its preheating temperature is 300℃.

[0080] Step S6: After the drill bit of the present invention is formed, the drill bit is taken out and subjected to stress-relieving annealing treatment; the annealing temperature is 350℃ and the time is 3.0h, which promotes the healing of microcracks and eliminates structural defects.

[0081] Where there is no conflict, the above embodiments and features described herein can be combined with each other.

[0082] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A self-sharpening diamond drill bit, comprising a drill bit body and a plurality of drill bit working bodies fixedly connected to the end of the drill bit body, wherein the drill bit working bodies are distributed circumferentially along the drill bit body, and a water gate is provided between adjacent drill bit working bodies, characterized in that: The drill bit working body includes a main working body and a secondary working body embedded in the main working body. The secondary working body is completely enclosed by the main working body. The main working body includes a first matrix and a first abrasive distributed within the first matrix. The secondary working body includes a second matrix and a second abrasive distributed within the second matrix. The wear resistance of the secondary working body is lower than that of the main working body. Both the main working body and the secondary working body are fan-shaped in the radial cross-section of the drill bit.

2. The self-sharpening diamond drill bit according to claim 1, characterized in that: The wear rate ML of the main working body is 0.58 × 10⁻⁶. -5 ~0.72×10 -5 The hardness of the first tire carcass is set to HRC15 to HRC25.

3. The self-sharpening diamond drill bit according to claim 1, characterized in that: The wear rate ML of the auxiliary working body is 0.88 × 10⁻⁶. -5 ~1.0×10 -5 The hardness of the second tire carcass is set to HRC6 to HRC10.

4. The self-sharpening diamond drill bit according to claim 1, characterized in that: The water inlet is set in a trapezoidal shape on the radial section of the drill bit, and the maximum width of the water inlet is set to 5 mm to 10 mm.

5. The self-sharpening diamond drill bit according to claim 1, characterized in that: The auxiliary working body is arranged in multiple layers at radial intervals along the drill bit steel body.

6. The self-sharpening diamond drill bit according to claim 5, characterized in that: The radial width of the auxiliary working body is 1.5 mm to 3.5 mm, and the arc length of the auxiliary working body is 5.0 mm to 9.0 mm.

7. The self-sharpening diamond drill bit according to claim 5, characterized in that: The radial width of the auxiliary working body increases along the direction close to the drill bit body.

8. The self-sharpening diamond drill bit according to claim 7, characterized in that: The auxiliary working bodies are arranged in two layers radially. The number of auxiliary working bodies in the outer layer is set to 1 to 3, and the number of auxiliary working bodies in the inner layer is set to 1 to 2. The auxiliary working bodies in the same layer are arranged circumferentially along the drill bit.

9. The self-sharpening diamond drill bit according to claim 7, characterized in that: The auxiliary working bodies are arranged in three layers radially. The number of auxiliary working bodies in the outer layer is set to 2 to 3, the number of auxiliary working bodies in the middle layer is set to 1 to 2, and the number of auxiliary working bodies in the inner layer is set to 1 to 2. The auxiliary working bodies in the same layer are arranged circumferentially along the drill bit.

10. The self-sharpening diamond drill bit according to any one of claims 5-9, characterized in that: The cross-sectional area of ​​the auxiliary working body accounts for 20% to 28% of the cross-sectional area of ​​the drill bit working body.

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