Cutting teeth of a drill bit and a drill bit

Abstract

The application discloses a cutting tooth of a drill bit and the drill bit. The cutting tooth comprises a mounting base and a hard cutting layer. The bottom end of the mounting base is a mounting end. The hard cutting layer is arranged at the top end of the mounting base. The top end of the mounting base is opposite to the bottom end of the mounting base. The mounting base comprises a contraction part and an intermediate part between the bottom end of the mounting base and the top end of the mounting base. The contraction part comprises at least one of the bottom end of the mounting base and the intermediate part of the mounting base. In the projection of the hard cutting layer in the thickness direction, the edge of the projection of the contraction part does not exceed the edge of the projection of the hard cutting layer, and at least part of the edge of the projection of the contraction part is contracted in the inside of the edge of the projection of the hard cutting layer. The above scheme can solve the problem that the cutting tooth of the drill bit adopts a cylindrical structure, which is prone to cause interference at the position adjacent to the tooth root.

Description

Technical Field

[0001] This invention relates to the field of drill bit design technology, and more particularly to a drill bit cutting teeth and a drill bit. Background Technology

[0002] Rock breaking is a primary task in drilling. Mechanical rock breaking remains the main method in oil and gas drilling. The drill bit is the rock-breaking tool used to break rocks and form the wellbore. The drill bit plays an irreplaceable role in drilling operations. Roller cone bits and PDC (polycrystalline diamond composite) bits are two commonly used types. Roller cone bits rely on the squeezing action of their cutting teeth on the rock at the bottom of the well to generate lateral pressure (i.e., shear force), thereby achieving rock breaking through this lateral pressure. However, roller cone bits have relatively low rock-breaking efficiency.

[0003] PDC drill bits achieve rock breaking through their efficient shearing force, gradually replacing roller cone drill bits in soft to medium-hard formations. Furthermore, rapid advancements in cutting tooth material technology, fundamental drill bit theory, and drill bit design technology have broadened the formation adaptability of PDC drill bits, increasing their proportion in total oil and gas drilling footage from 5% in the 1880s to 90%.

[0004] Drill bits with fixed cutting teeth, such as PDC drill bits, typically have multiple blades with multiple cutting teeth arranged radially along the drill bit (for PDC drill bits, the cutting teeth are PDC teeth).

[0005] like Figures 1 to 3 As shown, the PDC tooth 01 in the related technology is a cylindrical structure, and the connection force is generated in the cylindrical tooth hole on the blade by welding, so as to realize the fixed installation of the PDC tooth 01 on the blade 02.

[0006] The thickness of the PDC tooth is determined by the thickness of the polycrystalline diamond layer and the thickness of the cemented carbide substrate. The polycrystalline diamond layer is relatively thin, and the PDC tooth thickness mainly comes from the cemented carbide substrate. Therefore, the welding contact area between the cemented carbide substrate and the tooth hole is a crucial factor determining the weld strength. If the PDC tooth is too thin, the weld strength will decrease, potentially causing the PDC tooth to fall off during operation and leading to abnormal drill bit failure. Therefore, increasing the thickness of the cemented carbide substrate to increase the PDC tooth thickness is beneficial for improving the tooth's bonding strength.

[0007] However, while increasing tooth thickness can improve weld strength and make PDC teeth more robust, the PDC teeth located in the core of the drill bit generally employ a small rake angle for efficient cutting. Simultaneously, the sparse tooth distribution in the core of the drill bit results in a larger annular groove 04 area in the rock cut by the PDC teeth in the core. This can easily lead to interference between the rock and the side contact of the PDC teeth in the core of the drill bit (e.g., ...). Figure 3 (As shown), this damages the PDC teeth, causing abnormal failure of the drill bit.

[0008] When designing the cutting tooth arrangement for PDC drill bits, the design typically focuses only on the position of the cutting tooth's working face, while the spatial issues in the tooth thickness direction are easily overlooked. When high-density tooth arrangement is used on the outer shoulder of the drill bit, especially when PDC teeth require a side angle, there are often adjacent tooth roots of two PDC teeth that are prone to interference. To avoid this interference, designers generally reduce the tooth thickness of the cylindrical PDC teeth or change the original design parameters (including using smaller cutting teeth). However, the former cannot guarantee tooth strength, and the latter fails to achieve the original drill bit design effect.

[0009] PDC teeth on conventional PDC drill bits typically have a cylindrical structure, and the bores machined on the cutter blades are also cylindrical bores corresponding to the cylindrical PDC teeth. When the PDC teeth are working, the bottom surface of the bores on the cutter blades plays a major role in supporting the tangential load of the PDC teeth. Therefore, to ensure the strength of the bore bottom surface, the cutter blades must have sufficient thickness. However, increasing the thickness of the cutter blades reduces the flow space of the drill bit (i.e., the space formed between two adjacent cutter blades for discharging cuttings), leading to poor drilling fluid flow and making the drill bit prone to mud buildup. Of course, this problem is not limited to PDC teeth; other types of cutting teeth also present similar issues. Summary of the Invention

[0010] This invention discloses a cutting tooth and a drill bit, in order to solve the problem in the related art where the cutting teeth of the drill bit adopt a cylindrical structure, which easily leads to interference at the position of adjacent tooth roots.

[0011] To address the aforementioned technical problems, the present invention discloses the following technical solutions:

[0012] A drill bit's cutting teeth include a mounting base and a hard cutting layer, wherein:

[0013] The bottom end of the mounting base is the mounting end, the hard cutting layer is disposed at the top end of the mounting base, the top end of the mounting base is opposite to the bottom end of the mounting base, the mounting base includes a shrinkage portion, and the mounting base includes an intermediate portion located between the bottom end of the mounting base and the top end of the mounting base;

[0014] The contraction portion includes at least one of the bottom end of the mounting base and the middle portion of the mounting base. In the projection of the hard-cut layer in the thickness direction, the edge of the projection of the contraction portion does not extend beyond the edge of the projection of the hard-cut layer, and at least a portion of the edge of the projection of the contraction portion contracts inside the edge of the projection of the hard-cut layer.

[0015] Optionally, in the above-mentioned cutting teeth, the cutting teeth further include a reinforcing base, which is located between the mounting base and the hard cutting layer, and in the projection of the hard cutting layer in the thickness direction, the projection edge of the reinforcing base coincides with the projection edge of the hard cutting layer.

[0016] Optionally, in the above-mentioned cutting teeth, the reinforcing base and the mounting base are an integral structure to form the cemented carbide base of the cutting teeth.

[0017] Optionally, in the above-mentioned cutting teeth, the hard cutting layer is a circular layered structure, and the height H of the reinforcing base satisfies the following relationship: H≤D / 2, where D is the diameter of the hard cutting layer.

[0018] Optionally, in the above-mentioned cutting teeth, the hard cutting layer is a circular layered structure, and the tangent passing through the center of the hard cutting layer and parallel to the thickness direction of the hard cutting layer is the first tangent. The mounting base includes a first part and a second part located on both sides of the first tangent. The first part is a semi-cylindrical structure, and the second part is a semi-frustum structure.

[0019] Optionally, in the above-mentioned cutting teeth, the mounting base has a tapered structure, with the large end of the mounting base facing the hard cutting layer and the small end of the mounting base facing away from the hard cutting layer.

[0020] Optionally, in the above-mentioned cutting teeth, the mounting base is a rotary structure, wherein:

[0021] The generatrix of the rotary structure is a straight line inclined relative to the central axis of the cutting tooth; or, the generatrix of the rotary structure is a curved line bending away from the central axis of the cutting tooth; or, the generatrix of the rotary structure is a curved line bending closer to the central axis of the cutting tooth; or, the mounting base is a stepped shaft structure.

[0022] Optionally, in the above-mentioned cutting teeth, the mounting base is a multi-faceted pyramid structure, and the edges of the multi-faceted pyramid structure are straight edges, stepped edges, or curved edges.

[0023] Optionally, in the above-mentioned cutting teeth, the projections of the top end face of the mounting base and the bottom end face of the mounting base in the thickness direction of the hard cutting layer coincide, and the contraction portion is located between the top end of the mounting base and the bottom end of the mounting base.

[0024] A drill bit includes a drill bit body, a plurality of blades, and cutting teeth as described in any of the above. The plurality of blades are disposed on the drill bit body and are spaced apart along the circumferential direction of the drill bit body. Each blade is fixed with a cutting tooth, and the bottom end of the cutting tooth is fixed to the corresponding blade.

[0025] The technical solutions disclosed in the embodiments of the present invention have the following technical effects:

[0026] The cutting tooth disclosed in this invention improves upon the structure of cutting teeth in related technologies by designing a contraction portion on the mounting base. This ensures that the projection of the contraction portion in the thickness direction of the hard cutting layer not only does not exceed the edge of the hard cutting layer's projection, but also that at least a portion of the edge of the contraction portion's projection contracts inward to the inner side of the edge of the hard cutting layer's projection. In other words, the radial dimension of the contraction portion is smaller than the radial dimension of the hard cutting layer. In this invention, the contraction portion is at least one of the bottom end and the middle portion of the mounting base, resulting in a smaller radial dimension at the mounting end or near the mounting end of the cutting tooth. This prevents interference between the tooth roots after the cutting tooth is mounted on the blade.

[0027] Meanwhile, because the radial dimension of the mounting end or middle part of the cutting tooth adjacent to the blade wing is small, it occupies a smaller mounting space, thus allowing for more flexible arrangement on the blade wing. Furthermore, this type of cutting tooth structure alleviates inter-tooth interference problems, so there is no need to reduce the thickness of the cutting tooth, ensuring its mounting strength. Also, since the portion of the tooth hole adjacent to the blade wing is a constricted section, there is no need to design a large-diameter tooth hole, thus avoiding it occupying a large area on the blade wing. In this case, there is no need to thicken the blade wing, thereby preventing a reduction in flow channel space. Attached Figure Description

[0028] Figure 1 It is a partial cross-sectional view of the drill bit involved in the relevant technology;

[0029] Figure 2 This is a partial schematic diagram of the drill bit involved in the relevant technology;

[0030] Figure 3 This is a schematic diagram illustrating the interference between the cutting teeth of the drill bit and the rock during the drilling process, which is related to the relevant technology.

[0031] Figure 4This is a schematic diagram of the cutting teeth of the first type of drill bit disclosed in the embodiments of the present invention;

[0032] Figure 5 It is configured with Figure 4 A partial sectional view of the drill bit with the cutting teeth shown;

[0033] Figure 6 and Figure 7 These are schematic diagrams of the cutting teeth of the second type of drill bit disclosed in the embodiments of the present invention from different perspectives.

[0034] Figure 8 It is configured with Figure 6 and Figure 7 A partial sectional view of the drill bit with the cutting teeth shown;

[0035] Figure 9 It is configured with Figure 6 and Figure 7 A partial schematic diagram of the drill bit with cutting teeth shown;

[0036] Figure 10 It is configured with Figure 6 and Figure 7 The diagram shows the position of the cutting teeth between the cutting teeth and the rock during the drilling process.

[0037] Figure 11 This is a schematic diagram of the cutting tooth structure of the third type of drill bit disclosed in the embodiments of the present invention;

[0038] Figure 12 This is a schematic diagram of the cutting tooth structure of the fourth type of drill bit disclosed in the embodiments of the present invention;

[0039] Figure 13 This is a schematic diagram of the cutting tooth structure of the fifth type of drill bit disclosed in the embodiments of the present invention;

[0040] Figure 14 This is a schematic diagram of the cutting tooth structure of the sixth type of drill bit disclosed in the embodiments of the present invention;

[0041] Figure 15 This is a schematic diagram of the cutting tooth structure of the seventh type of drill bit disclosed in the embodiments of the present invention;

[0042] Figure 16 This is a schematic diagram of the cutting tooth structure of the eighth type of drill bit disclosed in the embodiments of the present invention;

[0043] Figure 17 This is a schematic diagram of the cutting teeth of the ninth type of drill bit disclosed in the embodiments of the present invention;

[0044] Figure 18 This is a schematic diagram of the cutting tooth structure of the tenth type of drill bit disclosed in the embodiments of the present invention;

[0045] Figure 19 This is a schematic diagram of the cutting teeth of the eleventh type of drill bit disclosed in the embodiments of the present invention;

[0046] Figure 20 This is a schematic diagram of the cutting teeth of the twelfth type of drill bit disclosed in the embodiments of the present invention;

[0047] Figure 21 This is a schematic diagram of the cutting teeth of the thirteenth drill bit disclosed in the embodiment of the present invention;

[0048] Figure 22 This is a schematic diagram of a drill bit structure disclosed in an embodiment of the present invention.

[0049] The components in the diagram are labeled as follows:

[0050] 01-PDC tooth, 02-blade, 03-rock, 04-annular groove, 10-mounting base, 11-bottom end, 12-top end, 13-middle part, 101-first part, 102-second part, 20-hard cutting layer, 30-reinforced base, 40-drill body, 41-threaded connection structure, 50-blade, 60-rock, 61-annular groove, 70-cutting tooth. Detailed Implementation

[0051] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0052] The technical solutions disclosed in the various embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0053] Please refer to Figures 4 to 22 This invention discloses a cutting tooth 70 for a drill bit. The disclosed cutting tooth 70 is part of the drill bit and is used to mount on the drill bit's cutting edge 50. The cutting tooth 70 disclosed in this invention can be a PDC tooth or other types of cutting teeth; this invention does not limit the specific type of cutting tooth 70. The cutting tooth 70 disclosed in this invention includes a mounting base 10 and a hard cutting layer 20.

[0054] The mounting base 10 is the portion of the cutting tooth 70 used for mounting onto the cutter wing 50. The mounting base 10 can be made of a single metal or alloy, allowing for easy welding and fixing to the tooth hole of the drill bit's cutter wing 50, thereby achieving the mounting of the cutting tooth 70. In this embodiment, the mounting base 10 has a bottom end 11, a top end 12, and a middle portion 13. The middle portion 13 of the mounting base 10 is located between the bottom end 11 and the top end 12 of the mounting base 10. It should be noted that the bottom end 11 and the top end 12 of the mounting base 10 are opposite ends of the mounting base 10.

[0055] The bottom end 11 of the mounting base 10 is the mounting end. During the mounting of the cutting teeth 70 onto the blade 50, at least the bottom end 11 of the mounting base 10 is fixed in the tooth hole of the blade 50. A hard cutting layer 20 is disposed at the top end 12 of the mounting base 10. The hard cutting layer 20 is the harder part of the cutting teeth 70, and the hardness of the hard cutting layer 20 is at least greater than the hardness of the mounting base 10. The hard cutting layer 20 is used to remove rock cuttings during drilling. The hard cutting layer 20 can be made of materials commonly used in the prior art. For example, the hard cutting layer 20 can be a polycrystalline diamond composite sheet. Of course, the hard cutting layer 20 can also be made of pure diamond material. The embodiments of the present invention do not limit the specific material of the hard cutting layer 20.

[0056] In this embodiment of the invention, the mounting base 10 includes a contraction portion, which may include at least one of the bottom end 11 of the mounting base 10 and the middle portion 13 of the mounting base 10. It should be noted that the radial dimension of the contraction portion is reduced relative to other portions of the mounting base 10 in the cutting tooth 70. In this text, the cutting tooth 70 has a central axis, which is perpendicular to the radial direction of the cutting tooth 70.

[0057] In the projection of the hard-cut layer 20 along its thickness direction, the edge of the projection of the contraction portion does not extend beyond the edge of the projection of the hard-cut layer 20, and a portion of the edge of the projection of the contraction portion lies within the corresponding edge of the projection of the hard-cut layer 20. That is, none of the portions of the edge of the projection of the contraction portion along the thickness direction of the hard-cut layer 20 extend beyond the edge of the projection of the hard-cut layer 20 along its thickness direction, and at least a portion of the edge of the projection of the contraction portion contracts to the inside of the edge of the projection of the hard-cut layer 20.

[0058] It should be noted that the thickness direction of the hard cutting layer 20 is parallel to the central axis of the cutting tooth 70.

[0059] The cutting tooth 70 disclosed in this embodiment of the invention improves upon the structure of cutting teeth in related technologies by designing a contraction portion on the mounting base 10. This ensures that the projection of the contraction portion in the thickness direction of the hard cutting layer 20 not only does not exceed the edge of the projection of the hard cutting layer 20, but also at least a portion of the edge of the projection of the contraction portion contracts to the inner side of the edge of the projection of the hard cutting layer 20. In other words, the radial dimension of the contraction portion is smaller than the radial dimension of the hard cutting layer 20. In this embodiment of the invention, the contraction portion is at least one of the bottom end 11 of the mounting base 10 and the middle portion 13 of the mounting base 10. This results in a smaller radial dimension at the mounting end or near the mounting end of the cutting tooth 70, thus preventing the problem of easy interference between the tooth roots after the cutting tooth 70 is mounted on the blade 50. Figure 8 and Figure 9 As shown. At the same time, since the radial dimension of the mounting end or middle part 13 of the adjacent blade 50 of the cutting tooth 70 is small, it can occupy a small mounting position, which is conducive to a more flexible arrangement on the blade 50.

[0060] Of course, because this type of cutting tooth 70 can alleviate the problem of inter-tooth interference, there is no need to reduce the thickness of the cutting tooth 70, thus ensuring the installation strength of the cutting tooth 70. At the same time, since the portion of the tooth hole adjacent to the blade 50 is a constricted section, there is no need to design a large-diameter tooth hole, and therefore it will not occupy a large area on the blade 50. In this case, there is no need to thicken the blade 50, thus avoiding a reduction in the flow channel space. Figure 10 As shown, during the drilling process, the annular groove 61 formed by the cutting teeth 70 cutting the rock 60 will not interfere with the cutting teeth 70.

[0061] In this embodiment of the invention, the hard cutting layer 20 can be directly connected to the mounting base 10, that is, the hard cutting layer 20 can be directly fixed to the top end 12 of the mounting base 10. Of course, the hard cutting layer 20 can also be indirectly fixed to the mounting base 10. As mentioned above, during the drilling process, the hard cutting layer 20 is the part of the cutting tooth 70 mainly used for stripping rock cuttings; therefore, the hardness of the hard cutting layer 20 is high, and at the same time, the higher the strength of the hard cutting layer 20, the more beneficial it is for cutting rock cuttings. Based on this, in a more preferred embodiment, the cutting tooth 70 may further include a reinforcing base 30, such as... Figure 4 , Figure 6 , Figure 7 , Figures 11 to 21The reinforcing base 30 is located between the mounting base 10 and the hard cutting layer 20. In the projection along the thickness direction of the hard cutting layer 20, the edge of the projected image of the reinforcing base 30 can coincide with the edge of the projected image of the hard cutting layer 20. In this case, the reinforcing base 30 can provide strong support for the hard cutting layer 20 from all directions, thereby indirectly enhancing the strength of the hard cutting layer 20, making it less prone to deformation or breakage during drilling. Optionally, the reinforcing base 30 has a cylindrical structure.

[0062] To improve support and connection strength, the reinforcing base 30 and the mounting base 10 can be made of the same material using integrated processing techniques such as casting and machining, thus making the reinforcing base 30 and the mounting base 10 an integral structure. Of course, when both the reinforcing base 30 and the mounting base 10 are made of cemented carbide, the reinforcing base 30 and the mounting base 10 can form the cemented carbide base of the cutting teeth 70.

[0063] An optional embodiment is that the hard cutting layer 20 can be a circular layered structure, such as... Figure 6 As shown, the height H of the reinforcing base 30 can satisfy the following relationship: H≤D / 2, where D is the diameter of the hard cutting layer 20.

[0064] The cutting tooth 70 disclosed in this embodiment of the invention can have various specific structures. In one optional embodiment, the hard cutting layer 20 can be a circular layered structure, and a first sectional surface is a cross-section passing through the center of the hard cutting layer 20 and parallel to the thickness direction of the hard cutting layer 20. The mounting base 10 can include a first part 101 and a second part 102 located on both sides of the first sectional surface. The first part 101 can be a semi-cylindrical structure, and the second part 102 can be a semi-frustum structure. Specifically, the semi-frustum structure can be a semi-circular frustum structure, such as... Figure 4 and Figure 5 As shown, it can also be a semi-square pyramidal structure, and the embodiments of the present invention are not limited thereto.

[0065] In some other embodiments, the mounting base 10 can be a tapered structure. The larger end of the mounting base 10 faces the hard cutting layer 20, and the smaller end of the mounting base 10 faces away from the hard cutting layer 20. The larger end of the mounting base 10 facing the hard cutting layer 20 provides better support for the hard cutting layer 20, while the smaller end of the mounting base 10 facing away from the hard cutting layer 20 is used for mounting on the blade wing 50, thus avoiding the need for excessive space. Furthermore, the tapered structure of the mounting base 10 also has the advantage of ease of manufacturing.

[0066] In a more specific embodiment, the mounting base 10 can be a rotating structure, such as... Figure 6 , Figure 7 , Figures 11 to 13As shown. For example, the generatrix of the rotary structure can be a straight line inclined relative to the central axis of the cutting tooth 70, such as... Figure 6 and Figure 7 As shown. For example, the generatrix of the rotating structure can be a curved line that bends away from the central axis relative to the central axis of the cutting tooth 70, such as... Figure 11 As shown. For example, the generatrix of the rotating structure can be a curved line that bends towards the central axis relative to the central axis of the cutting tooth 70, such as... Figure 12 As shown. The rotating structure of this type of structure makes the surface of the mounting base 10 smooth and rounded, which can effectively alleviate stress concentration and achieve a better supporting effect.

[0067] Of course, when the mounting base 10 is a rotating structure, the mounting base 10 can also be a stepped shaft structure, such as... Figure 13 As shown. This embodiment of the invention does not limit the specific rotating structure adopted by the mounting base 10.

[0068] In some other embodiments, the mounting base 10 can be a pyramidal structure, such as... Figures 14 to 18 As shown. For example, the edges of a pyramidal structure can be straight edges, such as... Figures 14 to 16 As shown. For example, the edges of a pyramidal structure can be stepped edges (such as...). Figure 17 (as shown) or curved edges (such as) Figure 18 (As shown). By using stepped or curved edges, the mounting base 10 can form a larger welding area, thereby improving the stability of the connection after welding. At the same time, both stepped and curved edges can create a larger space between themselves and the inner wall of the toothed hole on the blade 50 to fill the solder, thereby increasing the amount of solder filling and improving the firmness of the connection with the blade 50.

[0069] In some other embodiments, the projections of the top end face 12 and the bottom end face 11 of the mounting base 10 in the thickness direction of the hard-cut layer 20 coincide, such as... Figure 19 and Figure 20 As shown. The contraction portion is located between the top end 12 and the bottom end 11 of the mounting base 10. In this case, the contraction portion is essentially the middle portion 13 of the mounting base 10. In this structure, since the radial dimensions of both the bottom end 11 and the top end 12 of the mounting base 10 are larger than those of the middle portion 13, and the size of the middle portion 13 is smaller, interference with adjacent cutting teeth 70 can be avoided. At the same time, after the cutting teeth 70 are fixed into the tooth holes of the blade 50, the solder is fixed between the middle portion 13 and the inner wall of the tooth hole, thereby better restricting the positioning of the bottom end 11 of the mounting base 10, which has a larger radial dimension, in the direction of the central axis of the cutting teeth, achieving the purpose of preventing detachment.

[0070] Please refer to Figure 21 In other embodiments of the present invention, the hard cutting layer 20 has a non-planar structure. Specifically, the hard cutting layer 20 may have a raised ridge in the middle. This structure makes the cutting teeth 70 resemble an axe, which is beneficial to improving the rock-breaking efficiency of the cutting teeth 70. Of course, in this structure, the reinforcing base 30 is adapted to the shape of the hard cutting layer 20, thereby ensuring the reinforcing effect of the reinforcing base 30.

[0071] Based on the cutting tooth 70 disclosed in the embodiments of the present invention, please refer to... Figure 22 The present invention further discloses a drill bit, which may include a drill bit body 40, a plurality of blades 50 and the cutting teeth 70 described in the above embodiments.

[0072] The drill bit body 40 is the main structure of the drill bit. The tail end of the drill bit body 40 may be provided with a connecting structure to enable connection between the drill bit and the drill rod of the drilling equipment. Optionally, the connecting structure at the tail end of the drill bit body 40 can be a snap-fit ​​structure or a threaded connection structure 41; this embodiment of the invention does not limit the specific type of connecting structure. The front end of the drill bit body 40 is the drilling end, and the front end of the drill bit body 40 can provide mounting positions for multiple cutter wings 50.

[0073] The cutting blade 50 has toothed holes, and multiple cutting teeth 70 can be fixed to the multiple cutting blades 50 by welding. Specifically, one or more cutting teeth 70 can be fixed to each cutting blade 50, and the bottom end of the cutting tooth 70 is fixed to the corresponding cutting blade 50. The bottom end of the cutting tooth 70 includes at least the bottom end 11 of the mounting base 10, and may further include the middle part 13 of the mounting base 10. During the drilling process, the cutting teeth 70 perform a cutting action, thereby stripping away rock cuttings. The cutting teeth 70 can be fixed to the corresponding cutting blade 50 by welding, integral molding, or connecting with connectors. This embodiment of the invention does not limit the specific fixing method between the cutting blade 50 and the cutting teeth 70.

[0074] Multiple cutting blades 50 are disposed on the drill bit body 40. Specifically, the multiple cutting blades 50 protrude from the surface of the drill bit body 40. Optionally, the multiple cutting blades 50 can be fixedly disposed on the drill bit body 40 by welding or integral manufacturing. The embodiments of the present invention do not limit the specific connection method between the multiple cutting blades 50 and the drill bit body 40.

[0075] In this embodiment of the invention, multiple cutter blades 50 are spaced apart along the circumferential direction of the drill bit body 40. Two adjacent cutter blades 50 and the drill bit body 40 form flow channel spaces, and there are at least two flow channel spaces. These flow channel spaces are used to discharge rock cuttings during drilling.

[0076] In a more preferred embodiment, the reinforcing base 30 can also be welded into the tooth hole of the blade 50. In this case, the entire structure formed by the reinforcing base 30 and the mounting base 10 can be connected to the tooth hole by welding, thereby improving the stability of the connection of the cutting tooth 70 in the tooth hole. At the same time, the joint between the mounting base 10 and the reinforcing base 30 can bear the tangential force, thereby avoiding the bottom surface of the cutting tooth 70 bearing the tangential force, which can reduce the load on the bottom surface of the tooth hole, thereby reducing the mutual load between the cutting tooth 70 and the tooth hole, and ultimately helping to alleviate the problem that the cutting tooth 70 is prone to falling off due to the large load it is subjected to.

[0077] Of course, it should be noted that, in view of the technical effects brought about by the cutting teeth described in the above embodiments, the drill bit disclosed in the embodiments of the present invention also has corresponding technical effects. The discussion of the technical effects can be referred to above. Considering the brevity of the text, it will not be repeated here.

[0078] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of the present invention.

Claims

1. A cutting tooth of a drill bit, characterized in that, Includes a mounting base (10) and a hard-cut layer (20), wherein: The bottom end (11) of the mounting base (10) is the mounting end, the hard cutting layer (20) is disposed at the top end (12) of the mounting base (10), the top end (12) of the mounting base (10) is opposite to the bottom end (11) of the mounting base (10), the mounting base (10) includes a shrinkage portion, and the mounting base (10) includes an intermediate portion (13) located between the bottom end (11) of the mounting base (10) and the top end (12) of the mounting base (10). The contraction portion includes at least one of the bottom end (11) of the mounting base (10) and the middle portion (13) of the mounting base (10), wherein, in the projection of the hard cutting layer (20) in the thickness direction, the edge of the projection of the contraction portion does not extend beyond the edge of the projection of the hard cutting layer (20), and at least a portion of the edge of the projection of the contraction portion is contracted inside the edge of the projection of the hard cutting layer (20); The hard-cutting layer (20) is a circular layered structure. A first cut surface is a cross-section passing through the center of the hard-cutting layer (20) and parallel to its thickness direction. The mounting base (10) includes a first portion (101) and a second portion (102) located on either side of the first cut surface. The first portion (101) is a semi-cylindrical structure, and the second portion (102) is a semi-frustum structure; or... The mounting base (10) is a conical structure, with the large end of the mounting base (10) facing the hard cutting layer (20) and the small end of the mounting base (10) facing away from the hard cutting layer (20). The mounting base (10) is a rotary structure, with the generatrix of the rotary structure being a straight line inclined relative to the central axis of the cutting tooth, or the generatrix of the rotary structure being a curved line bending away from the central axis of the cutting tooth, or the generatrix of the rotary structure being a curved line bending closer to the central axis of the cutting tooth. The mounting base (10) is a stepped shaft structure; or the mounting base (10) is a multi-faceted pyramid structure, with the edges of the multi-faceted pyramid structure being straight edges, stepped edges, or arc-shaped edges.

2. The cutting tooth according to claim 1, characterized in that, The cutting tooth further includes a reinforcing base (30) located between the mounting base (10) and the hard cutting layer (20). In the projection of the hard cutting layer (20) in the thickness direction, the projection edge of the reinforcing base (30) coincides with the projection edge of the hard cutting layer (20).

3. The cutting tooth according to claim 2, characterized in that, The reinforcing base (30) and the mounting base (10) are an integral structure to form the cemented carbide base of the cutting teeth.

4. The cutting tooth according to claim 2, characterized in that, The hard cutting layer (20) is a circular layered structure, and the height H of the reinforcing base (30) satisfies the following relationship: H≤D / 2, where D is the diameter of the hard cutting layer (20).

5. A drill bit, characterized in that, The drill bit includes a drill body (40), a plurality of blades (50) and a cutting tooth (70) as described in any one of claims 1 to 4. The plurality of blades (50) are disposed on the drill body (40) and are distributed at intervals along the circumferential direction of the drill body (40). Each blade (50) is fixed with a cutting tooth (70), and the bottom end of the cutting tooth (70) is fixed to the corresponding blade (50).

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