Mechanical anti-erosion PDC (Polycrystalline Diamond Compact) drill bit

Abstract

The utility model discloses a mechanical anti-erosion PDC (Polycrystalline Diamond Compact) drill bit, which relates to the technical field of drilling, and comprises a drill bit part, a handle part and an anti-erosion component, the handle part is connected to the lower end of the drill bit part, and a central flow channel communicated with the drill bit part and a branch flow channel for communicating the central flow channel with the outside are arranged along the axial direction of the handle part; the anti-erosion assembly is arranged in the branch flow channel, when the fluid pressure of the center flow channel is larger than the set pressure, the anti-erosion assembly enables the center flow channel to be communicated with the branch flow channel, and when the fluid pressure of the center flow channel is smaller than the set pressure, the anti-erosion assembly enables the branch flow channel to be closed. The anti-erosion assembly is arranged in the branch flow channel communicated with the center flow channel, so that when the fluid pressure drop of the drill bit exceeds a set pressure value, part of fluid in the center flow channel can enter the branch flow channel through the anti-erosion assembly, the impact force of the fluid acting on the drill bit part is reduced, and the risk of excessive erosion to the drill bit is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of drilling, in particular to a mechanical anti-erosion PDC drill bit. Background Art

[0002] PDC (Polycrystalline Diamond Compact) drill bits are commonly used rock-breaking tools for oil drilling. They are widely used in oil fields for their high mechanical drilling speed, long service life, and safe and reliable use. However, with the continuous improvement of high-pressure jet drilling technology, radical parameter drilling has become the norm, and drill bits are facing increasingly harsh construction conditions. In particular, the problem of excessive erosion of steel-body PDC drill bits caused by high pump pressure and high displacement has become increasingly prominent. In severe cases, the cutting teeth will fall off from the tooth holes, thus affecting the service life and drilling efficiency of the drill bit. Therefore, it is urgent to improve the erosion resistance of PDC drill bits.

[0003] Conventional steel-body PDC drill bits have WC wear-resistant alloy welded on the surface of the drill bit, but this method can no longer meet the needs of high-pressure jet drilling. In addition, Smith has launched an anti-erosion drill bit using 3D printed armor technology, but due to the complexity of the drill bit structure and process, as well as high cost issues, it is not conducive to promotion and application. Utility Model Content

[0004] In view of the defects existing in the prior art, the purpose of the utility model is to provide a mechanical anti-erosion PDC drill bit to solve the problem in the prior art that the drill bit is affected in service life and drilling efficiency due to excessive erosion.

[0005] In order to achieve the above purpose, the technical solution adopted by the utility model is:

[0006] The present application provides a mechanically erosion-resistant PDC drill bit, comprising:

[0007] Drill head;

[0008] A shank connected to the lower end of the drill head, with a central flow channel connected to the drill head and a branch flow channel connecting the central flow channel with the outside being provided along the axial direction of the shank;

[0009] The anti-erosion component is arranged in the above-mentioned branch flow channel. When the pressure of the above-mentioned central flow channel is greater than the set pressure, the above-mentioned anti-erosion component connects the above-mentioned central flow channel with the above-mentioned branch flow channel. When the pressure of the above-mentioned central flow channel is less than the set pressure, the above-mentioned anti-erosion component closes the above-mentioned branch flow channel.

[0010] In some optional embodiments, the above-mentioned anti-erosion component includes:

[0011] A main body, which is arranged in the branch flow channel and connected to the handle, wherein a stepped hole is arranged in the main body, and a small hole section of the stepped hole is connected to the central flow channel;

[0012] A supporting portion, which is located in the large hole section of the stepped hole, and is provided with a leakage hole connecting the stepped hole with the outside;

[0013] The elastic member has two ends respectively abutting against the abutting portion and the piston, so that when the fluid pressure of the central flow channel is less than the set pressure, the elastic member abuts against the piston at the connection between the small hole section and the large hole section of the stepped hole; when the fluid pressure of the central flow channel is greater than the set pressure, the elastic member is compressed, and the piston is away from the connection between the small hole section and the large hole section of the stepped hole.

[0014] In some optional embodiments, the above-mentioned abutting portion includes:

[0015] An annular boss, which is located in the large hole section of the stepped hole and connected to the main body, and a plurality of the leakage holes are provided on the annular boss and are evenly distributed in the circumferential direction;

[0016] The push piece is threadably matched with the annular boss and extends into the stepped hole to abut against the elastic piece to adjust the pre-tightening force of the elastic piece.

[0017] In some optional embodiments, the inner wall of the branch flow channel is provided with threads that cooperate with the threads of the main body.

[0018] In some optional embodiments, a limiting groove is provided at the end portion where the pushing member abuts against the elastic member, and one end of the elastic member is clamped in the limiting groove.

[0019] In some optional embodiments, the anti-erosion component further includes a retaining spring, which is engaged in the branch flow channel and abuts against the end of the main body away from the central flow channel.

[0020] In some optional embodiments, the outer wall of the main body is provided with an annular receiving groove, and the anti-erosion component further includes a sealing ring, which is located in the receiving groove and abuts against the inner wall of the branch flow channel to seal the gap between the main body and the inner wall of the branch flow channel.

[0021] In some optional embodiments, the piston is spherical, and has a diameter larger than the diameter of the small hole section of the stepped hole and smaller than the diameter of the large hole section of the stepped hole.

[0022] In some optional embodiments, the piston includes a connecting portion and a sealing portion, the connecting portion abuts against the other end of the elastic member away from the main body portion, the sealing portion is conical, and its large diameter end is connected to the connecting portion, and has a diameter larger than the diameter of the small hole section of the stepped hole and smaller than the diameter of the large hole section of the stepped hole, and the small diameter end of the sealing portion abuts against the end portion where the small hole section and the large hole section of the stepped hole are connected.

[0023] In some optional embodiments, the branch flow channels are opened along the radial direction of the shank, and have the same number as the blades of the drill head and correspond one to one.

[0024] Compared with the prior art, the advantages of the utility model are:

[0025] By arranging an anti-erosion component in the branch flow channel connected to the central flow channel, during the high-parameter (high pump pressure, high displacement) drilling process in an oil field, when the pressure drop of the fluid flowing through the drill bit exceeds the set pressure value, the fluid can enter the branch flow channel through the anti-erosion component and flow to the annulus between the drill head and the well wall, thereby reducing the pressure drop through the drill head. The fluid pressure and velocity flowing out of the drill head nozzle are reduced, thereby reducing the impact force acting on the drill head and reducing the risk of excessive erosion of the drill bit. At the same time, the fluid flows into the annulus above the root of the drill bit blade diameter protection, and will not affect the flow field of the drill head itself. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0027] Figure 1 This is a schematic structural diagram of a mechanical anti-erosion PDC drill bit of the utility model;

[0028] Figure 2 for Figure 1 A schematic cross-sectional structure diagram of ;

[0029] Figure 3 for Figure 1 Schematic diagram of the structure explosion of the first embodiment of the middle anti-erosion component;

[0030] Figure 4 for Figure 3 A schematic cross-sectional structure diagram of ;

[0031] Figure 5 for Figure 1 Schematic diagram of the structure explosion of the second embodiment of the middle anti-erosion component;

[0032] Figure 6 for Figure 5 A schematic cross-sectional structure diagram of ;

[0033] Figure 7 A structural schematic diagram of the main body;

[0034] Figure 8 is another structural schematic diagram of the main body;

[0035] Fig. 9 It is a schematic diagram of the structure of the push piece.

[0036] In the figure: 1, drill head; 11, blade; 2, handle; 21, central flow channel; 22, branch flow channel; 3, anti-erosion component; 31, main body; 311, stepped hole; 3111, small hole section; 3112, large hole section; 32, supporting part; 321, leakage hole; 322, annular boss; 3221, internal thread; 323, push piece; 3231, external thread; 3232, slot; 3233, through hole; 33, elastic part; 34, piston; 341, connecting part; 342, sealing part; 35, retaining spring; 36, sealing ring. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0038] The embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings.

[0039] On the one hand, if Figure 1 and Figure 2 As shown, the present application provides a mechanically anti-erosion PDC drill bit, comprising a drill head 1, a shank 2 and an anti-erosion assembly 3. The drill head 1 and the shank 2 are connected in sequence, and the high-pressure fluid pressure in the drill bit is partially unloaded through the anti-erosion assembly 3, thereby avoiding impact damage to the drill head caused by excessive fluid pressure, and the problem that the drill bit service life and drilling efficiency are affected by excessive erosion of the drill bit.

[0040] Specifically, the shank 2 is connected to the lower end of the drill head 1, and a central flow channel 21 connected to the drill head 1 and a branch flow channel 22 connecting the central flow channel 21 with the outside are opened along the axial direction of the shank 2; the anti-erosion component 3 is arranged in the branch flow channel 22, and when the fluid pressure of the central flow channel 21 is greater than the set pressure, the anti-erosion component 3 connects the central flow channel 21 with the branch flow channel 22, and when the fluid pressure of the central flow channel 21 is less than the set pressure, the anti-erosion component 3 closes the branch flow channel 22.

[0041] It can be understood that when the fluid pressure of the central flow channel 21 is greater than the set pressure, the anti-erosion component 3 connects the central flow channel 21 with the branch flow channel 22, so that the fluid in the central flow channel 21 can flow out from the branch flow channel 22, reducing the fluid pressure of the central flow channel 21 flowing through the drill bit, reducing the fluid speed sprayed from the nozzle to the drill bit, reducing the impact damage to the surface of the drill bit material, and reducing the erosion effect on the drill bit; when the pressure of the central flow channel 21 does not exceed the set pressure, the anti-erosion component 3 will not work at this time, and the fluid will be directly sprayed from the central flow channel 21 to the drill bit through the nozzle on the drill bit.

[0042] Therefore, the anti-erosion component 3 can adjust the connection and closing of the branch flow channel 22 and the central flow channel 21 according to the fluid pressure in the central flow channel 21 .

[0043] In some optional embodiments, such as Figures 3 to 6 As shown, the anti-erosion assembly 3 includes a main body 31, a supporting part 32 and an elastic member 33. The main body 31 is arranged in the branch flow channel 22 and connected to the handle 2. A stepped hole 311 is arranged in the main body 31. The small hole section 3111 of the stepped hole 311 is connected to the central flow channel 21. The supporting part 32 is located in the large hole section 3112 of the stepped hole 311. A leakage hole 321 is opened on the supporting part 32 to connect the stepped hole 311 with the outside. The two ends of the elastic member 33 respectively abut against the abutting portion 32 and the piston 34, so that when the fluid pressure of the central flow channel 21 is lower than the set pressure, the elastic member 33 abuts against the piston 34 at the connection between the small hole section 3111 and the large hole section 3112 of the stepped hole 311; when the fluid pressure of the central flow channel 21 is higher than the set pressure, the elastic member 33 is compressed, and the piston 34 moves away from the connection between the small hole section 3111 and the large hole section 3112 of the stepped hole 311.

[0044] It can be understood that the stepped hole 311 includes a large hole section 3112 and a small hole section 3111, wherein the small hole section 3111 is connected to the central flow channel 21, and the large hole section 3112 is connected to the outside. The elastic member 33 located in the large hole section 3112 provides a holding force to the piston 34, thereby holding the piston 34 against the connection between the large hole section 3112 and the small hole section 3111, blocking the small hole section 3111, and sealing the central flow channel 21 from the outside. At this time, the piston 34 is in a stationary state. When the pressure of the fluid in the central flow channel 21 is greater than the set pressure, the fluid in the central flow channel 21 pushes the piston 34 until it is away from the small hole section 3111 of the stepped hole 311, and the small hole section 3111 is connected to the large hole section 3112, and the fluid flows from the central flow channel 21 into the stepped hole 311 and is discharged from the drain hole 321.

[0045] Therefore, the value of the set pressure is related to the elastic coefficient of the elastic member 33, and the corresponding elastic member 33 can be selected as needed. It should be noted that when the fluid pressure in the central flow channel 21 is greater, the elastic member 33 is compressed to a greater extent, and when the large hole section 3112 is also filled with fluid, the pressure difference between the large hole section 3112 and the small hole section 3111 will also affect the compression degree of the elastic member 33.

[0046] In this example, the elastic member 33 is a spring, so the preload force of the spring can be adjusted by adjusting the wire diameter, number of turns, stiffness, etc. of the spring.

[0047] During installation, the piston 34 is first placed in the stepped hole 311, and then one end of the spring is pressed against the piston 34 to the connection between the large hole section 3112 and the small hole section 3111 of the stepped hole 311. Finally, the pressing part 32 is installed to press against the other end of the spring and fix the relative position.

[0048] In some optional embodiments, the above-mentioned supporting portion 32 includes an annular boss 322 and a pushing piece 323, the annular boss 322 is located in the large hole section 3112 of the above-mentioned stepped hole 311 and is connected to the above-mentioned main body 31, and the above-mentioned leakage hole 321 is opened on the above-mentioned annular boss 322; the pushing piece 323 is threadedly matched with the above-mentioned annular boss 322, and extends into the above-mentioned stepped hole 311 to resist the above-mentioned elastic piece 33 to adjust the preload force of the above-mentioned elastic piece 33.

[0049] That is to say, Fig. 9As shown, the push piece 323 is cylindrical, and an external thread 3231 is provided on its outer wall, and an internal thread 3221 is provided on the inner wall of the annular boss 322 to be threadedly matched with the external thread 3231, and the push piece 323 is threadedly connected to the main body 31 through the annular boss 322. Through the threaded match between the push piece 323 and the annular boss 322, the length of the push piece 323 extending into the large hole section 3112 is adjusted to change the preload force of the spring. The longer the push piece 323 extends into the large hole section 3112, the greater the preload force of the spring, and the greater the value of the set pressure at this time.

[0050] Therefore, the anti-erosion component 3 can flexibly adjust the size of the set opening pressure according to corresponding needs, and has better applicability.

[0051] In this example, a slot 3232 is formed at one end of the pushing member 323 away from the elastic member 33 , so as to facilitate the rotation of the pushing member 323 and adjust the pre-tightening force of the elastic member 33 .

[0052] Optionally, the pushing member 323 is provided with a through hole 3233 to connect the stepped hole 311 with the outside.

[0053] It can be understood that when the piston 34 leaves the connection between the large hole section 3112 and the small hole section 3111, the fluid can enter the stepped hole 311 from the central flow channel 21, and can not only flow out from the leakage hole 321, but also flow out from the through hole 3233, so that the pressure relief effect is better, and it is avoided that the fluid pressure in the central flow channel 21 exceeds the set pressure due to untimely fluid discharge, and the piston 34 still cannot be pushed away from the connection between the small hole section 3111 and the large hole section 3112.

[0054] In some optional embodiments, the leakage holes 321 are arranged at intervals along the circumference of the annular boss 322 , and the axis of the leakage holes 321 is parallel to the axis of the annular boss 322 .

[0055] The number and diameter of the leakage holes 321 determine the efficiency of fluid outflow and also indirectly affect the set pressure. Therefore, the leakage holes 321 can be set accordingly as needed.

[0056] In some optional embodiments, the inner wall of the branch flow channel 22 is provided with threads, which are threadedly matched with the main body 31 .

[0057] That is to say, Figure 7 As shown, the main body 31 and the handle 2 are detachably connected. The purpose of this arrangement is to allow different anti-erosion components 3 to be replaced as needed to adjust the set pressure when the central flow channel 21 is depressurized.

[0058] In other embodiments, Figure 8As shown, the main body 31 can also be fixedly connected to the handle 2 by welding or other methods.

[0059] In some optional embodiments, a limiting groove is provided at the end of the pushing member 323 that abuts against the elastic member 33, and one end of the elastic member 33 is clamped in the limiting groove.

[0060] It can be understood that in order to prevent the elastic member 33 from being displaced or bent during the extension and retraction process, a limiting groove is provided to fix the relative position between the elastic member 33 and the pushing member 323 .

[0061] In some optional embodiments, the anti-erosion component 3 further includes a retaining spring 35 , which is engaged in the branch flow channel 22 and abuts against the end of the main body 31 away from the central flow channel 21 .

[0062] It can be understood that in order to further prevent the anti-erosion assembly 3 from falling off from the branch flow channel 22 due to the pressure impact of the fluid in the central flow channel 21, a clamping spring 35 is provided to fix the main body 31 in the branch flow channel 22. It should be noted that the clamping spring 35 is annular, abuts against the end of the main body 31, and avoids the leakage hole 321.

[0063] In some optional embodiments, the outer wall of the main body 31 is provided with an annular receiving groove, and the anti-erosion component 3 further includes a sealing ring 36 , which is located in the receiving groove and abuts against the inner wall of the branch flow channel 22 .

[0064] It can be understood that the function of the sealing ring 36 is to seal the connection between the main body 31 and the handle 2. The sealing ring 36 can be made of a material with elastic restoring force.

[0065] In some optional embodiments, such as Figure 3 and Figure 4 As shown, the piston 34 is spherical, and its diameter is larger than the diameter of the small hole section 3111 of the stepped hole 311 , and smaller than the diameter of the large hole section 3112 of the stepped hole 311 .

[0066] It can be understood that the spherical piston 34 is easier to process, but is easily separated from the elastic member 33 under the impact of the fluid.

[0067] In some optional embodiments, such as Figure 5 and Figure 6As shown, the piston 34 includes a connecting portion 341 and a sealing portion 342. The connecting portion 341 abuts against the other end of the elastic member 33 away from the main body portion 31. The sealing portion 342 is conical, and its large diameter end is connected to the connecting portion 341, and its diameter is larger than the diameter of the small hole section 3111 of the stepped hole 311, and smaller than the diameter of the large hole section 3112 of the stepped hole 311. The small diameter end of the sealing portion 342 abuts against the end where the small hole section 3111 and the large hole section 3112 of the stepped hole 311 are connected.

[0068] It can be understood that the connecting portion 341 is inserted in the center of the spring, so that the relative position of the piston 34 and the spring remains fixed and will not be disturbed by the impact of the fluid. The sealing portion 342 is conical, which not only moves better inside and outside the small hole section 3111, but also the outer inclined surface of the cone can play a certain guiding role in the flow of the fluid.

[0069] Preferably, no matter the piston 34 is spherical or includes a connecting portion 341 and a sealing portion 342 , the connection between the large hole section 3112 and the small hole section 3111 of the stepped hole 311 , i.e., the L-shaped bend, has an arc-shaped chamfer to avoid damage to the piston 34 .

[0070] The piston 34 is made of a material having elastic restoring force.

[0071] In some optional embodiments, the branch flow channels 22 are opened along the radial direction of the shank 2 , and the number of the branch flow channels 22 is the same as that of the blades 11 of the drill head 1 and corresponds one to one.

[0072] That is to say, a plurality of branch flow channels 22 are spaced apart along the circumference of the shank 2, and an anti-erosion component 3 is provided in each branch flow channel 22. The branch flow channels 22 have the same number as the blades of the drill head 1 and correspond one to one, so that each blade wing 11 can be depressurized accordingly to protect the blade wing 11.

[0073] In other embodiments, the branch flow channel 22 may also be located inside the inclined hole at the root of the blade 11 .

[0074] In some optional embodiments, the main body 31, the abutting portion 32 and the piston 34 of the anti-erosion component 3 are all made of hard alloy or alloy steel. If alloy steel is used, an anti-erosion coating is sprayed on the surface.

[0075] The working principle of the embodiment of the present application is as follows: when the fluid pressure of the central flow channel 21 is greater than the set pressure, the fluid in the central flow channel 21 pushes the piston 34 until it is away from the small hole section 3111 of the stepped hole 311, the small hole section 3111 is connected to the large hole section 3112, the fluid flows from the central flow channel 21 into the stepped hole 311, and is discharged from the leakage hole 321; when the pressure of the central flow channel 21 does not exceed the set pressure, the elastic member 33 holds the piston 34 at the connection between the large hole section 3112 and the small hole section 3111, blocks the small hole section 3111, and closes the central flow channel 21 from the outside.

[0076] The utility model discloses a mechanical anti-erosion PDC drill bit, by arranging an anti-erosion component 3 in a branch flow channel 22 connected to a central flow channel 21, so that in the process of high parameter (high pump pressure, high displacement) drilling in oil drilling, when the pressure drop of the drill bit fluid exceeds the set pressure value, it can enter into the branch flow channel 22 through the anti-erosion component 3 and flow to the annulus between the drill head 1 and the well wall, thereby reducing the pressure drop through the drill head 1, and the fluid pressure and velocity of the drilling fluid flowing out through the drill head nozzle are reduced, thereby reducing the impact force acting on the drill head and reducing the risk of excessive erosion of the drill bit. At the same time, the fluid flows into the annulus above the root of the drill blade diameter protection, and will not affect the flow field of the drill head itself. By setting the anti-erosion component 3 as a mechanical structure including a main body 31, a supporting part 32 and an elastic part 33, the cost is lower, and it is easy to install and manufacture, which is conducive to promotion. By setting the push member 32 3 is threadedly matched with the annular boss 322, so that the preload force of the elastic member 33 can be adjusted by rotating the push piece 323 to achieve the purpose of fine-tuning the pressure drop through the drill bit; the main body 31 and the handle 2 are detachably connected, so that different anti-erosion components 3 can be replaced as needed, which can be customized according to the drill bit size and threadedly connected to the drill bit body, and the installation and disassembly are simple and convenient; by providing a retaining spring 35, the anti-erosion component 3 is further prevented from falling off from the branch flow channel 22 due to the pressure impact of the fluid in the central flow channel 21; the piston 34 is configured to include a connecting portion 341 and a sealing portion 342, and the connecting portion 341 is inserted in the center of the spring, so that the relative position of the piston 34 and the spring remains fixed and will not be disturbed by the impact of the fluid, and the sealing portion 342 is conical, which not only moves better in and out of the small hole section 3111, but also the conical outer inclined surface can also play a certain guiding role in the flow of the fluid.

[0077] In the description of the present application, it should be noted that the terms "upper", "lower", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. Unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0078] It should be noted that, in this application, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0079] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.

Claims

1. A mechanical anti-erosion PDC drill bit, characterized in that: include: Drill head (1); A shank (2) connected to the lower end of the drill head (1), with a central flow channel (21) in communication with the drill head (1) and a branch flow channel (22) in communication with the central flow channel (21) and the outside being provided along the axial direction of the shank (2); An anti-erosion component (3) is arranged in the branch flow channel (22). When the pressure of the central flow channel (21) is greater than a set pressure, the anti-erosion component (3) connects the central flow channel (21) with the branch flow channel (22). When the pressure of the central flow channel (21) is less than the set pressure, the anti-erosion component (3) closes the branch flow channel (22).

2. The PDC drill bit according to claim 1, characterized in that: The anti-erosion component (3) comprises: a main body (31), which is arranged in the branch flow channel (22) and connected to the handle (2), wherein a stepped hole (311) is arranged in the main body (31), and a small hole section (3111) of the stepped hole (311) is in communication with the central flow channel (21); A supporting portion (32) is located in the large hole section (3112) of the stepped hole (311), and a leakage hole (321) is provided on the supporting portion (32) for connecting the stepped hole (311) with the outside; The elastic member (33) has two ends respectively abutting against the abutting portion (32) and the piston (34), so that when the fluid pressure of the central flow channel (21) is less than a set pressure, the elastic member (33) abuts against the piston (34) at the connection between the small hole section (3111) and the large hole section (3112) of the stepped hole (311); when the fluid pressure of the central flow channel (21) is greater than the set pressure, the elastic member (33) is compressed, and the piston (34) moves away from the connection between the small hole section (3111) and the large hole section (3112) of the stepped hole (311).

3. The PDC drill bit according to claim 2, characterized in that: The abutting portion (32) comprises: an annular boss (322), which is located in the large hole section (3112) of the stepped hole (311) and connected to the main body (31); a plurality of the leakage holes (321) are provided on the annular boss (322) and are evenly distributed in the circumferential direction; A push piece (323) is threadably matched with the annular boss (322) and extends into the stepped hole (311) to abut against the elastic piece (33) to adjust the pre-tightening force of the elastic piece (33).

4. The PDC drill bit according to claim 2, characterized in that: The inner wall of the branch flow channel (22) is provided with a thread which is matched with the thread of the main body (31).

5. The PDC drill bit according to claim 3, characterized in that: A limiting groove is provided at the end of the pushing member (323) that abuts against the elastic member (33), and one end of the elastic member (33) is clamped in the limiting groove.

6. The PDC drill bit according to claim 2, characterized in that: The anti-erosion component (3) also includes a clamping spring (35), which is clamped in the branch flow channel (22) and abuts against the end of the main body (31) away from the central flow channel (21).

7. The PDC drill bit according to claim 2, characterized in that: The outer wall of the main body (31) is provided with an annular receiving groove, and the anti-erosion component (3) also includes a sealing ring (36), which is located in the receiving groove and abuts against the inner wall of the branch flow channel (22) to seal the gap between the main body (31) and the inner wall of the branch flow channel (22).

8. The PDC drill bit according to claim 2, characterized in that: The piston (34) is spherical, and has a diameter larger than the diameter of the small hole section (3111) of the stepped hole (311) and smaller than the diameter of the large hole section (3112) of the stepped hole (311).

9. The PDC drill bit according to claim 2, characterized in that: The piston (34) comprises a connecting portion (341) and a sealing portion (342). The connecting portion (341) abuts against the other end of the elastic member (33) away from the main body (31). The sealing portion (342) is conical, and its large diameter end is connected to the connecting portion (341). The diameter is larger than the diameter of the small hole section (3111) of the stepped hole (311) and smaller than the diameter of the large hole section (3112) of the stepped hole (311). The small diameter end of the sealing portion (342) abuts against the end of the small hole section (3111) and the large hole section (3112) of the stepped hole (311).

10. The PDC drill bit according to claim 1, wherein: The branch flow channels (22) are opened along the radial direction of the shank (2) and have the same number as the blades (11) of the drill head (1) and correspond one to one.

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