An adaptive nozzle and drill bit

Abstract

The application relates to a self-adaptive nozzle and drill bit, which comprises an outer sleeve, a side wall of which is provided with a secondary liquid inlet, and an inner wall of one end of which is provided with a first limiting cavity extending in an axial direction; an inner sleeve coaxially sleeved in the outer sleeve, two ends of the inner sleeve being a primary liquid inlet and a liquid outlet respectively, an outer wall of the inner sleeve being provided with a first limiting boss and a second limiting boss in an axial direction at intervals, the second limiting boss being slidably arranged in the first limiting cavity, the first limiting boss and the second limiting boss and the outer sleeve surrounding a second limiting cavity, the secondary liquid inlet being communicated with the second limiting cavity; and an elastic member arranged in the first limiting cavity and abutting against the second limiting boss and the outer sleeve at two ends respectively. By communicating the primary liquid inlet and the secondary liquid inlet with a main flow channel and a branch flow channel of a drill body respectively, self-adaptive optimization of the hydraulic performance of the drill bit under full well conditions is realized, and the working efficiency and service life of the drill bit under different drilling working conditions are improved.

Description

Technical Field

[0001] This application relates to the field of PDC drill bit nozzles, and particularly to an adaptive nozzle and drill bit. Background Technology

[0002] Complex operating conditions frequently occur in oil drilling, such as encountering lost circulation or collapsed formations. In such cases, it is necessary to reduce the flow rate to balance the formation and fluid column pressures, ensure safe drilling, and prevent stuck drill bits. However, while reducing the flow rate is effective in addressing lost circulation, it reduces the drill bit's ability to carry rock and its cooling capacity, leading to a decrease in mechanical drilling rate. This is because the reduced flow rate slows down the upward return speed of the drilling fluid, making it less effective at carrying rock. Furthermore, the cooling effect of the composite blades on the outer shoulder of the drill bit deteriorates, causing thermal damage to the composite blades and resulting in wear and tooth breakage failure. For example, with the continuous improvement of high-pressure jet drilling technology, aggressive parameter drilling has become the norm, and drill bits face increasingly harsh operating conditions. In particular, the problem of excessive erosion of steel PDC drill bits caused by high pump pressure and high flow rate is becoming increasingly prominent. In severe cases, cutting teeth may fall out of the tooth cavity, thereby affecting the service life of the drill bit and drilling efficiency. Summary of the Invention

[0003] This application provides an adaptive nozzle and drill bit to solve the problem of insufficient adaptability to drilling displacement in the prior art: under low displacement conditions, the drill bit composite blade has defects such as poor cleaning and cooling; while under high pump pressure and high displacement conditions, the cutting teeth are prone to fall off due to excessive erosion, which affects the life of the drill bit and drilling efficiency.

[0004] In a first aspect, an adaptive nozzle is provided, comprising: The outer sleeve has a secondary liquid inlet on its side wall and a first limiting cavity extending axially on the inner wall of one end. The inner sleeve is slidably disposed coaxially within the outer sleeve, with its two ends being the main liquid inlet and the liquid outlet, respectively. The outer wall of the inner sleeve is provided with a first limiting boss and a second limiting boss spaced apart along the axial direction. The second limiting boss is slidably disposed within the first limiting cavity. The first limiting boss and the second limiting boss together with the outer sleeve form a second limiting cavity. The secondary liquid inlet is connected to the second limiting cavity. An elastic element is disposed within the first limiting cavity, with its two ends abutting against the second limiting boss and the outer sleeve, respectively.

[0005] In some embodiments, the inner cross-section of the outlet is circular, elliptical, square, or irregular. The inner sleeve has an arc-shaped groove on the outer wall near the liquid outlet, and the outer sleeve has a limiting groove. A limiting pin is installed in the limiting groove, and the limiting pin slides in the arc-shaped groove.

[0006] In some embodiments, both the first limiting boss and the second limiting boss are provided with a first sealing groove in the circumferential direction, and a first sealing element is provided in the first sealing groove.

[0007] In some embodiments, a sleeve coaxially arranged with the outer sleeve is included, the sleeve being fixedly connected to one end of the outer sleeve near the main liquid inlet, the inner sleeve being slidably connected to the sleeve, and the end of the elastic element away from the second limiting boss abutting against the end face of the sleeve.

[0008] In some embodiments, a first stepped surface is formed inside the first limiting cavity, and a plurality of positioning bosses are provided circumferentially on the first stepped surface.

[0009] In some embodiments, the outer wall of the outer sleeve is provided with a second sealing groove in the circumferential direction. The second sealing groove is disposed between the limiting groove and the secondary liquid inlet, and a second sealing element is provided in the second sealing groove.

[0010] In some embodiments, the outer wall of the outer sleeve is threaded at the end near the main inlet.

[0011] In some embodiments, the outer wall of the outer sleeve is provided with a third sealing groove, the third sealing groove is disposed between the thread and the secondary liquid inlet, and a third sealing element is provided in the third sealing groove.

[0012] In some embodiments, the outer wall of the outer sleeve is provided with a fourth sealing groove, the fourth sealing groove is disposed between the thread and the main liquid inlet, and a fourth sealing element is provided in the fourth sealing groove.

[0013] Secondly, a drill bit is provided, comprising: The drill bit body has a main flow channel and a branch flow channel connected to the main flow channel along the axial direction, and the adaptive nozzle is installed in the inner circumference of the drill bit body. The main inlet is connected to the main flow channel, and the secondary inlet is connected to the branch flow channel.

[0014] This application provides an adaptive nozzle and drill bit. Drilling fluid flows in from the main inlet and the secondary inlet. Under high flow rate conditions, when the drilling fluid flows through the adaptive nozzle, a portion of the drilling fluid enters the second limiting cavity formed by the first and second limiting bosses through the secondary inlet. When the pressure in the second limiting cavity exceeds the preset elastic force of the elastic element, the elastic element is compressed, pushing the inner sleeve to slide away from the bottom of the well. The outlet fluid moves away from the bottom of the well, and the fluid velocity and impact force at the outlet decrease accordingly, thereby reducing the direct jet impact of drilling fluid on the drill bit and effectively mitigating the risk of drill bit erosion.

[0015] Within the normal displacement range, the pressure in the second limiting cavity and the elastic force of the elastic element remain balanced, the position of the inner sleeve remains stable, and the nozzle maintains a normal spray state, ensuring stable cleaning and cooling effects for the drill bit.

[0016] When the discharge rate decreases, the pressure in the second limiting chamber drops, and the elastic element elongates under the action of the restoring force, pushing the inner sleeve towards the bottom of the well, so that the outlet fluid is closer to the bottom of the well, thereby maintaining sufficient injection speed and impact force, ensuring that the composite plate on the outer shoulder of the drill bit can still get sufficient cooling and cleaning at low discharge rates, and avoiding the weakening of cleaning ability due to the decrease in discharge rate. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the drill bit structure provided in an embodiment of this application; Figure 2 This is a schematic diagram of the cross-sectional structure of a drill bit provided in an embodiment of this application; Figure 3 This is a schematic diagram of the adaptive nozzle structure provided in an embodiment of this application; Figure 4 This is a schematic diagram of the adaptive nozzle explosion structure provided in an embodiment of this application; Figure 5 This is a schematic diagram of the adaptive nozzle cross-sectional structure provided in an embodiment of this application; Figure 6 This is a schematic diagram of the cross-sectional structure of the outer sleeve and the inner sleeve in the adaptive nozzle provided in an embodiment of this application.

[0019] In the diagram: 1. Drill bit body; 11. Main flow channel; 12. Branch flow channel; 13. Cutting blade; 14. Cutting teeth; 15. Chip removal groove; 16. Connector; 17. Water hole; 2. Adaptive nozzle; 21. Outer sleeve; 211. Secondary liquid inlet; 212. First limiting cavity; 213. Limiting groove; 214. Limiting pin; 215. First stepped surface; 216. Positioning boss; 217. Second sealing groove; 218. Second sealing element; 219. Thread; 2110. Third sealing groove; 2111. Third sealing element; 2112. Fourth sealing groove; 2113. Fourth sealing element; 22. Inner sleeve; 221. Main liquid inlet; 222. Liquid outlet; 223. First limiting boss; 224. Second limiting boss; 225. Second limiting cavity; 226. Arc groove; 227. First sealing groove; 228. First sealing element; 23. Elastic components; 24. Sleeve. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0021] This application provides an adaptive nozzle that can solve the problem of insufficient adaptability to drilling displacement in related technologies: under low displacement conditions, the drill bit composite blade has defects in poor cleaning and cooling; while under high pump pressure and high displacement conditions, the cutting teeth are prone to fall off due to excessive erosion, affecting the life of the drill bit and drilling efficiency.

[0022] First, combined Figure 1 and Figure 2 The overall drill bit structure is described below. The drill bit provided by this invention mainly includes a drill bit body 1 and an adaptive nozzle 2 mounted thereon. The drill bit body 1 has a main channel 11 for conveying the main drilling fluid along the axial direction, and one or more branch channels 12 communicating with the main channel 11. The adaptive nozzle 2 is circumferentially installed in corresponding water holes 17 on the drill bit body 1. The installation relationship is as follows: the main fluid inlet 221 of the adaptive nozzle 2 is connected to the main channel 11 of the drill bit body 1, and the secondary fluid inlet 211 of the adaptive nozzle 2 is connected to the branch channels 12 of the drill bit body 1. The crown of the drill bit body 1 has several circumferentially distributed cutter wings 13, and PDC cutting teeth 14 are installed on the cutter wings 13, forming chip removal grooves 15 between the cutter wings 13. The tail of the drill bit body 1 is usually a threaded joint 16 for connecting the drill string. Drilling fluid flows in from the drill string and is distributed through the main channel 11. Part of it directly enters the main inlet 221 of the adaptive nozzle 2, while the other part is led to the water hole 17 through the branch channel 12 and enters the second limiting cavity 225 through the secondary inlet 211 on the side wall of the outer sleeve 21.

[0023] The number of adaptive nozzles 2 can correspond to the number of blades 13, or it can be more than the number of blades, depending on the actual working conditions on site.

[0024] Figures 3 to 6The specific structure of the adaptive nozzle 2 is shown in detail. The core of the adaptive nozzle 2 lies in its dynamic adjustment mechanism, which mainly consists of three major components: the outer sleeve 21, the inner sleeve 22, and the elastic element 23.

[0025] The outer sleeve 21 constitutes the static housing of the nozzle. Its side wall has a secondary inlet 211 for introducing fluid into the branch channel 12. On the inner wall of the outer sleeve 21 near the main inlet 221, a first limiting cavity 212 extending axially is machined.

[0026] The inner sleeve 22 is coaxially disposed inside the outer sleeve 21 and can slide along the axial direction. Its axial length is greater than that of the outer sleeve 21. Its two ends are the main liquid inlet 221 and the liquid outlet 222, respectively. During installation, the liquid outlet 222 is close to the blade 13. The outer wall of the inner sleeve 22 is provided with a first limiting boss 223 and a second limiting boss 224 at intervals along the axial direction. The second limiting boss 224 is slidably disposed in the first limiting cavity 212. The first limiting boss 223 and the second limiting boss 224 and the outer sleeve 21 form a second limiting cavity 225. The secondary liquid inlet 211 is connected to the second limiting cavity 225.

[0027] The elastic element 23 is located in the first limiting cavity 212, and its two ends abut against the second limiting boss 224 and the outer sleeve 21 respectively, and is used to control the relative position of the liquid outlet 222 of the inner sleeve 22 and the outer sleeve 21.

[0028] In this embodiment, the outer sleeve 21 and the inner sleeve 22 can be made of hard alloy or alloy steel. If they are alloy steel, the surface needs to be coated with an anti-corrosion coating.

[0029] Furthermore, in this embodiment, the elastic element 23 is a spring. The spring calculates the drill bit pressure drop based on the drilling fluid discharge value during field use. The fluid pressure acting on the inner sleeve 22 in each adaptive nozzle 2 is calculated through the drill bit pressure drop, and the spring parameters are selected based on the pressure value.

[0030] Furthermore, the inner cross-section of the outlet 222 is circular, elliptical, square, or irregular. The outer wall of the inner sleeve 22 is provided with an arc-shaped groove 226 near the liquid outlet 222. The outer sleeve 21 is provided with a limiting groove 213. A limiting pin 214 is installed in the limiting groove 213. The limiting pin 214 passes through the limiting groove 213 and engages with the arc-shaped groove 226 and slides.

[0031] Because the cross-section of the inner wall of the outlet 222 is circular, elliptical, square, or irregular, the irregular flow channel structure has the ability to directionally shape the jet pattern. The sliding pair formed by the arcuate groove 226 on the outer wall of the inner sleeve 22 and the upper limit pin 214 of the outer sleeve 21 introduces additional degrees of freedom to the nozzle. During the axial extension and retraction of the inner sleeve 22 driven by drilling fluid pressure changes, the interaction between the limit pin 214 and the arcuate groove 226 transforms the linear motion into the rotational motion of the inner sleeve 22 around its axis. This expands the impact area of ​​the jet at the bottom of the well from a static single point or a small fixed area to a dynamic, larger-area scanning coverage. This not only improves the efficiency of the drilling fluid in the flooding cleaning of cuttings at the bottom of the well, reducing the possibility of repeated cuttings breakage and the formation of cushion layers, but also more uniformly cools the cutting teeth in multiple directions on the outer shoulder of the drill bit, avoiding localized overheating. Meanwhile, the dynamically changing jet angle helps to disturb the flow field at the bottom of the well, improve the movement path of cuttings, and further enhance the rock-carrying capacity under low discharge conditions. This enables the comprehensive improvement of rock-breaking efficiency and drill bit reliability by optimizing the hydraulic energy distribution without increasing pump pressure and discharge.

[0032] Furthermore, both the first limiting boss 223 and the second limiting boss 224 are provided with a first sealing groove 227 in the circumferential direction, and a first sealing element 228 is provided in the first sealing groove 227.

[0033] By setting a first sealing groove 227 around the two limiting bosses and installing a first sealing element 228, a reliable dynamic seal can be formed between the first limiting boss 223, the second limiting boss 224 and the inner wall of the outer sleeve 21, effectively preventing drilling fluid from leaking into areas outside the second limiting cavity 225, thereby ensuring the pressure of the second limiting cavity 225.

[0034] Furthermore, it also includes a sleeve 24 coaxially arranged with the outer sleeve 21. The sleeve 24 is fixedly connected to one end of the outer sleeve 21 near the main liquid inlet 221. The inner sleeve 22 is slidably connected to the sleeve 24. The end of the elastic element 23 away from the second limiting boss 224 abuts against the end face of the sleeve 24. The sleeve 24 and the outer sleeve 21 are integrally installed in the water hole 17 of the drill bit body 1.

[0035] A sleeve 24 is added and fixedly connected coaxially to the outer sleeve 21, and one end of the elastic element 23 is abutted against the end face of the sleeve 24, providing a stable and reliable mounting reference and support surface for the elastic element 23. At the same time, the sleeve 24 plays an auxiliary guiding role in the sliding of the inner sleeve 22, improving the reliability and durability of the entire adaptive adjustment mechanism.

[0036] Furthermore, a first stepped surface 215 is formed within the first limiting cavity 212, and a plurality of positioning bosses 216 are provided circumferentially on the first stepped surface 215. The positioning bosses 216 are cylindrical, and the number can be 3-5. Through the plurality of positioning bosses 216, the contact area and frictional resistance between the inner sleeve 22 and the outer sleeve 21 are reduced, so that a small annular gap is maintained between the inner sleeve 22 and the inner wall of the outer sleeve 21, effectively avoiding direct and complete contact between the two metal surfaces without liquid film lubrication and pressure buffer. This fundamentally eliminates the risk of static friction sticking or jamming that may be caused by metal adsorption or impurity embedding, ensuring that the inner sleeve 22 is always in a freely sliding state even under zero-pressure or low-pressure start-up conditions.

[0037] Furthermore, the outer wall of the outer sleeve 21 is provided with a second sealing groove 217 circumferentially. The second sealing groove 217 is located between the limiting groove 213 and the secondary inlet 211, and a second sealing element 218 is provided inside the second sealing groove 217. This prevents fluid from flowing out from the gap between the outer sleeve 21 and the water hole 17, helps maintain the design pressure distribution of the flow channel inside the drill bit's water hole, optimizes the overall hydraulic performance, and reduces the potential erosion of the drill bit body by fluid leakage.

[0038] Furthermore, the outer wall of the outer sleeve 21 is provided with a thread 219 near the main inlet 221. The thread 219 is used to connect the adaptive nozzle 2 to the drill bit body 1. In some alternative embodiments, the adaptive nozzle 2 can be installed in the water hole 17 of the drill bit body 1 by brazing.

[0039] Furthermore, the outer wall of the outer sleeve 21 is provided with a third sealing groove 2110, which is located between the thread 219 and the secondary inlet 211. A third sealing element 2111 is provided inside the third sealing groove 2110. This is used to seal the fluid flowing out of the branch channel 12 from eroding the thread 219 of the outer sleeve 21. By protecting the integrity of the thread, it ensures a firm and sealed connection between the adaptive nozzle and the drill bit body, preventing the nozzle from loosening, falling off, or leaking due to damage to the connection. This ensures the continuous and stable operation of the drill bit under harsh conditions such as high pressure and high flow rate, and extends the service life and maintenance cycle of the nozzle and the drill bit as a whole.

[0040] Furthermore, the outer wall of the outer sleeve 21 is provided with a fourth sealing groove 2112, which is located between the thread 219 and the main fluid inlet 221. A fourth sealing element 2113 is provided inside the fourth sealing groove 2112. This is used to prevent drilling fluid from flowing into the thread through the gap between the outer sleeve 21 and the water hole 17.

[0041] In this embodiment, the first seal 228, the second seal 218, the third seal 2111, and the fourth seal 2113 are all elastic rubber rings.

[0042] The working principle of this adaptive nozzle and drill bit is as follows: Under high displacement and high pump pressure conditions, drilling fluid flows through the drill bit. Most of the fluid enters the central flow channel of the inner sleeve 22 through the main inlet 221 from the main flow channel 11, while a portion of the fluid enters the second limiting cavity 225 through the branch flow channel 12 and the secondary inlet 211. When the fluid pressure in the second limiting cavity 225 exceeds the preset elastic force of the elastic element 23, the pressure pushes the second limiting boss 224, compressing the elastic element 23, thereby causing the entire inner sleeve 22 to slide away from the bottom of the well. As a result, the outlet 222 moves backward relative to the drill bit crown, increasing the distance the jet travels to the bottom of the well, and relatively reducing the impact force and flow velocity, thus effectively reducing the risk of direct erosion of the drill bit body, cutter wings, and cutting teeth by the high-pressure fluid.

[0043] When the adaptive nozzle 2 is in a relatively stable state, that is, when the drilling fluid discharge is constant, the pump pressure is stable within a certain range, the pressure difference between the main flow channel 11 and the branch flow channel 12 is 0, and the state is balanced, the adaptive nozzle 2 will not open. At this time, it is the same as the use state of a conventional nozzle. In addition, there is fluid in the second limiting cavity 225 between the inner sleeve 22 and the outer sleeve 21. Under the action of fluid pressure, the elastic element 23 is in the initial compression state and has a certain pre-tightening force.

[0044] When the drilling flow rate decreases, the flow rate and pressure of the branch channel 12 decrease accordingly, leading to a decrease in pressure within the second limiting cavity 225. At this time, the compressed spring extends under its restoring force, pushing the second limiting boss 224 and the inner sleeve 22 towards the bottom of the well. This brings the outlet 222 closer to the bottom of the well and the cutting teeth on the outer shoulder of the drill bit, maintaining the impact velocity and cleaning force of the jet to the target area even with a reduced total flow rate. This ensures the cooling and cleaning effect of critical parts of the drill bit at low flow rates, as well as basic rock-carrying capacity.

[0045] In summary, the beneficial effects of this invention are as follows: This invention can achieve drill bit erosion prevention during use. In high-parameter (high pump pressure, high displacement) drilling in oil wells, when the drill bit pressure drop exceeds a certain value, when the drilling fluid enters the drill bit crown water hole 17 through the main channel 11 of the drill bit body, a portion of the drilling fluid will enter the gap between the inner sleeve 22 and the outer sleeve 21 end face of the adaptive nozzle 2 from the secondary inlet 211. When the drilling fluid pressure difference exceeds the adaptive nozzle opening threshold, the elastic element 23 is compressed, and the inner sleeve 22 moves away from the bottom of the well. At this time, the drilling fluid outlet flow from the inner sleeve 22 will move away from the bottom of the well, and the fluid pressure and velocity of the drilling fluid flowing out through the drill bit nozzle are reduced, which reduces the impact force acting on the drill bit body and reduces the risk of excessive drill bit erosion.

[0046] This invention can achieve stable drill bit cooling and cleaning, and rock-carrying capacity under low-displacement drilling conditions. When the displacement is reduced, the pressure difference between the fluid thrust and the elastic element 23 in the adaptive nozzle is less than the adaptive nozzle opening threshold. The elastic element 23 extends, and the inner sleeve 22 in the adaptive nozzle moves closer to the bottom of the well. At this time, the drilling fluid outlet flow from the inner sleeve 22 will approach the bottom of the well, and the outlet velocity and impact force remain stable. The cooling and cleaning capacity of the composite plate on the outer shoulder of the drill bit will not be weakened.

[0047] The adaptive nozzle in this invention adjusts its opening threshold according to the drilling fluid flow rate, and the size of the elastic element 23 can be adjusted to achieve a predetermined effect. While the adaptive nozzle extends and retracts according to the pressure, it can simultaneously rotate. The rotation mechanism is achieved by machining a spiral groove on the inner sleeve and engaging it with a pin, allowing rotation to occur while the inner sleeve extends and retracts. The nozzle outlet shape can be irregular, allowing the outlet fluid flow to cover a wider range during rotation.

[0048] In summary, this invention, through an adaptive structure combining fluid pressure feedback and spring mechanical response, enables the nozzle to automatically adjust the axial position of the inner sleeve according to the real-time drilling fluid discharge rate, thereby changing the jet target distance and impact characteristics. This achieves the intelligent adjustment goal of preventing erosion at high discharge rates and maintaining performance at low discharge rates. Simultaneously, the optional addition of a rotating mechanism further optimizes the hydraulic energy distribution at the bottom of the well. The entire solution is compact, responsive, and enhances the adaptability and overall efficiency of the PDC drill bit to complex and variable drilling conditions.

[0049] In the description of this application, it should be noted that the terms "upper," "lower," 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 application and simplifying the description, and do not 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 application. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0050] It should be noted that in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0051] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. An adaptive nozzle, characterized in that, It includes: The outer sleeve (21) has a secondary liquid inlet (211) on its side wall and a first limiting cavity (212) extending axially on its inner wall at one end. The inner sleeve (22) is slidably disposed coaxially within the outer sleeve (21), with its two ends being the main liquid inlet (221) and the liquid outlet (222) respectively. The outer wall of the inner sleeve (22) is provided with a first limiting boss (223) and a second limiting boss (224) spaced apart along the axial direction. The second limiting boss (224) is slidably disposed within the first limiting cavity (212). The first limiting boss (223) and the second limiting boss (224) together with the outer sleeve (21) form a second limiting cavity (225). The secondary liquid inlet (211) is connected to the second limiting cavity (225). The elastic element (23) is disposed in the first limiting cavity (212), and its two ends abut against the second limiting boss (224) and the outer sleeve (21) respectively.

2. The adaptive nozzle as described in claim 1, characterized in that: The inner cross-section of the liquid outlet (222) is circular, elliptical, square or irregular; The inner sleeve (22) has an arc-shaped groove (226) on the outer wall near the liquid outlet (222), and the outer sleeve (21) has a limiting groove (213). A limiting pin (214) is installed in the limiting groove (213), and the limiting pin (214) slides with the arc-shaped groove (226).

3. The adaptive nozzle as described in claim 1, characterized in that: Both the first limiting boss (223) and the second limiting boss (224) are provided with a first sealing groove (227) in the circumferential direction, and a first sealing element (228) is provided in the first sealing groove (227).

4. The adaptive nozzle as described in claim 1, characterized in that: It also includes a sleeve (24) coaxially arranged with the outer sleeve (21), the sleeve (24) being fixedly connected to one end of the outer sleeve (21) near the main liquid inlet (221), the inner sleeve (22) being slidably connected to the sleeve (24), and the end of the elastic element (23) away from the second limiting boss (224) abutting against the end face of the sleeve (24).

5. The adaptive nozzle as described in claim 1, characterized in that: A first step surface (215) is formed in the first limiting cavity (212), and a plurality of positioning bosses (216) are provided in the circumferential direction of the first step surface (215).

6. The adaptive nozzle as described in claim 1, characterized in that: The outer wall of the outer sleeve (21) is provided with a second sealing groove (217) in the circumferential direction. The second sealing groove (217) is located between the limiting groove (213) and the secondary liquid inlet (211). A second sealing element (218) is provided in the second sealing groove (217).

7. The adaptive nozzle as described in claim 1, characterized in that: The outer wall of the outer sleeve (21) is provided with a thread (219) at the end near the main liquid inlet (221).

8. The adaptive nozzle as described in claim 7, characterized in that: The outer wall of the outer sleeve (21) is provided with a third sealing groove (2110), the third sealing groove (2110) is located between the thread (219) and the secondary liquid inlet (211), and a third sealing element (2111) is provided in the third sealing groove (2110).

9. The adaptive nozzle as described in claim 7, characterized in that: The outer wall of the outer sleeve (21) is provided with a fourth sealing groove (2112), which is located between the thread (219) and the main liquid inlet (221). A fourth sealing element (2113) is provided in the fourth sealing groove (2112).

10. A drill bit, characterized in that, It includes: The drill bit body (1) has a main flow channel (11) and a branch flow channel (12) connected to the main flow channel (11) in the axial direction, and the drill bit body (1) is circumferentially mounted with an adaptive nozzle (2) as described in any one of claims 1 to 9. The main inlet (221) is connected to the main flow channel (11), and the secondary inlet (211) is connected to the branch flow channel (12).

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