阅读说明：本技术 一种可实现自适应缓冲功能的金刚石钻头 (Diamond drill bit capable of realizing self-adaptive buffering function ) 是由 牛世伟 杨迎新 张灯 张春亮 黄奎林 包泽军 吴俊豪 王宏 于 2021-09-14 设计创作，主要内容包括：本发明公开了一种可实现自适应缓冲功能的金刚石钻头,具体包括刀翼和切削齿,在钻头上至少设置一个缓冲模块,所述缓冲模块包括缓冲部、限位部及复位装置；所述缓冲模块的缓冲部通过与岩石之间的互作用,实现相对于刀翼的收缩和伸出趋势运动。本发明能够在导向钻进、复合钻进以及其他复杂运动工况下,或钻进硬地层、不均质地层条件下,钻头受到较大冲击载荷缓冲部的回缩速度超过一定阈值时,缓冲部在限位部的卡阻作用下其收缩运动受到阻碍,从而可起到吸收冲击载荷,减少或避免切削齿冲击损坏的目的,同时,在钻头进入稳定破岩过程中,缓冲部做自由的伸出和收缩趋势运动,减少或避免缓冲部对刀翼切削齿侵入深度的影响,保障钻头的破岩效率。(The invention discloses a diamond drill bit capable of realizing a self-adaptive buffering function, which specifically comprises a blade and a cutting tooth, wherein at least one buffering module is arranged on the drill bit, and the buffering module comprises a buffering part, a limiting part and a resetting device; the buffer part of the buffer module realizes the contraction and extension trend movement relative to the blade through the interaction with the rock. The buffer part can be blocked in the contraction motion under the blocking action of the limiting part when the retraction speed of the buffer part with larger impact load of the drill bit exceeds a certain threshold value under the conditions of guiding drilling, composite drilling and other complex motion working conditions, or drilling in hard strata and heterogeneous strata, so that the purposes of absorbing impact load and reducing or avoiding the impact damage of the cutting teeth can be achieved, meanwhile, in the process that the drill bit enters stable rock breaking, the buffer part freely moves in the extending and contracting trend, the influence of the buffer part on the invasion depth of the cutting teeth of the cutter wings is reduced or avoided, and the rock breaking efficiency of the drill bit is guaranteed.)

1. The utility model provides a can realize diamond bit of self-adaptation buffering function, includes the bit body and extends the wing from the bit body, be provided with the cutting tooth on the wing, set up a buffering module, its characterized in that on the drill bit at least: the buffer module comprises a buffer part, a limiting part and a reset device;

the buffer part is movably connected with the blade, the buffer part comprises a buffer support and buffer teeth, and a clamping groove is formed in the buffer part;

the limiting part comprises a fixed support and a rotating part, and the rotating part is rotationally connected with the support through a pin shaft;

the reset device comprises a buffer part reset device and a rotating part reset device, wherein the buffer part reset device realizes the reset of the buffer part, and the rotating part reset device realizes the reset of the rotating part.

2. The diamond drill bit capable of realizing the adaptive buffering function according to claim 1, wherein: in a free state, the height difference H between the highest point of the buffer part and the highest point of the cutting edge of the cutting tooth is-D and not more than H and not more than D, and D is the diameter of the cutting tooth.

3. The diamond drill bit capable of realizing the adaptive buffering function according to claim 1, wherein: the buffer part comprises buffer teeth and a buffer support, the buffer teeth are embedded and fixed on the buffer support, or the buffer teeth can be connected on the buffer support in a free rotating mode, or the buffer teeth and the buffer support are of an integrated structure.

4. The diamond drill bit capable of realizing the adaptive buffering function according to claim 3, wherein: the buffering teeth are spherical teeth, wedge-shaped teeth, conical teeth or PDC teeth.

5. The diamond drill bit capable of realizing the adaptive buffering function according to claim 1, wherein: the buffer part resetting device is a compression spring, and the rotating part resetting device is a torsion spring.

6. The diamond drill bit capable of realizing the adaptive buffering function according to claim 1, wherein: the buffer module is arranged on the drill bit with the PDC cutting structure compounded with other rock breaking structures including the movable rock breaking structure.

Technical Field

The invention belongs to the technical field of drilling engineering, mining engineering, building foundation engineering, geological drilling, geothermal drilling, hydrographic drilling, tunnel engineering, shield tunneling, trenchless and the like, and particularly relates to a diamond drill bit capable of realizing a self-adaptive buffering function.

Background

Rock breaking is an essential problem in drilling. Mechanical rock breaking is still the main operation mode in oil and gas drilling at present, a drill bit is a rock breaking tool for breaking rock and forming a shaft, the drill bit plays an irreplaceable role in drilling engineering as an absolute main force, and a roller cone drill bit and a PDC drill bit are most commonly used. The roller bit generates lateral pressure by means of the extrusion effect of teeth on rock at the bottom of a well, the lateral pressure forms shearing force, the rock is broken and fails after reaching the shearing strength, and the utilization rate of the rock is reduced by the transmission and conversion of energy in the process. The PDC drill bit breaks rock in an efficient shearing mode and gradually replaces the roller bit in soft to medium-hard strata. In particular, rapid progress in cutting tooth material technology, bit basic theory and bit design technology widens the formation adaptability of PDC bits, and the proportion of PDC bits in the total drilling footage of oil and gas drilling has increased from 5% to 90% in the eighties of the nineteenth century.

Fixed cutter bits, typically PDC bits, typically have a plurality of blades with a plurality of cutting teeth disposed radially along the bit (for PDC bits, the cutting teeth are primarily polycrystalline diamond compacts, compacts for short, or PDC teeth). The data show that deep complex formations, which account for only 20% of the total footage, cost 80% of the total cost of the entire drilling cycle. The difficult-to-drill stratum mainly refers to the stratum with poor drillability, and is particularly represented by high hardness, high inhomogeneous degree, strong grindability, high temperature and the like of rock. These rock property conditions may exist in various complex combinations, variations and are generally unpredictable, especially when the conditions are expressed in deep formations such as deep wells and ultra-deep wells. The drilling bit has short drilling life in complex and difficult-to-drill stratum, needs to consume more bits, and causes frequent tripping, which becomes one of the technical bottlenecks for restricting cost reduction and efficiency improvement of drilling engineering.

During drilling, the cutting teeth of the PDC drill bit overcome the ground stress to bite into the stratum under the action of the bit weight, and the stratum materials are sheared and crushed under the driving of the torque. Compared with a rock breaking mode of impact rolling of the roller bit, the required driving torque is larger. When drilling into deep hard-to-drill stratum, especially when drilling into soft and hard staggered gravel-containing stratum, the depth of the drill bit penetrating into the stratum changes frequently, and the drill bit vibrates violently in the circumferential direction, the transverse direction and the axial direction. In fact, when a PDC drill bit is subjected to impact load, particularly, impact load from the axial direction of the drill bit, the drill bit frequently jumps up (leaves the bottom of the well) and drops down (contacts the bottom of the well), and if the impact is large, the impact load between the cutting teeth and the rock is large on the one hand, and the cutting teeth are damaged by the impact. On the other hand, the cutting teeth impact the rock at a high speed, the depth of the cutting teeth invading the rock is increased instantly, the drill bit stops rotating and is in a viscous state, at the moment, the drill string is continuously twisted under the rotation of the rotary table, when the energy accumulated in the drill string is enough to overcome the friction torque between the drill bit and the stratum, the drill bit can accelerate and rotate at twice or several times of the rotary table rotation speed, the vibration of the bottom drilling tool is intensified, and the rotation torque of the drill bit is also fluctuated severely. In the process of drilling a deep well, underground lithological characters are variable, the heterogeneity is serious, a drill bit is subjected to larger resistance moment at the bottom of the well, intermittent tripping and longitudinal vibration of a drill rod are frequent, the factors are main reasons for tooth falling and breaking of the drill bit, failure of a bearing and damage of an underground tool, and the drilling speed and the service life of the drill bit are severely limited. Therefore, how to increase the service life of the PDC drill bit in deep hard-to-drill stratum and reduce the sensitivity of the torque of the drill bit to the bit pressure is an important technical problem of prolonging the service life of the downhole drilling tool and the drill bit and improving the drilling efficiency.

Therefore, researchers in the field propose a diamond bit (application number: 201810138571. X) suitable for hard formation drilling, the patent proposes that a buffer base extends out of the front of a blade, and a buffer element is arranged on the buffer base, so that when a complex and difficult formation is drilled, the circumferential span can be effectively reduced, the circumferential impact vibration is weakened, and meanwhile, the buffer element can share part of axial drilling pressure, the axial impact is reduced, and the PDC teeth are protected. However, the buffer element in the patent is a fixed buffer element, the relative height between the buffer element and the diamond teeth is a fixed value, the stratum adaptation range of the fixed buffer element is narrow, and for the stratum with complicated and changeable lithology, especially when drilling a soft stratum from a hard stratum, the fixed buffer element can reduce the intake capacity of the diamond teeth and reduce the drilling speed of a drill bit.

Disclosure of Invention

The invention aims to: aiming at the existing problems, the diamond drill bit capable of realizing the self-adaptive buffering function is provided, so that the problem that the cutting teeth of the drill bit rapidly lose efficacy due to impact under the working conditions of complex formations difficult to drill, complex vibration, especially directional drilling, composite drilling and the like is solved, the purpose of protecting the cutting teeth is achieved, and the service life of the drill bit is prolonged. The PDC drill bit is particularly used for solving the problems that the existing PDC drill bit is insufficient in impact resistance, large in torque fluctuation and poor in directional drilling performance in directional drilling.

The purpose of the invention is realized by the following technical scheme:

a diamond drill bit capable of realizing a self-adaptive buffering function comprises a drill bit body and blades extending out of the drill bit body, wherein cutting teeth are arranged on the blades, at least one buffering module is arranged on the drill bit, and the buffering module comprises a buffering part, a limiting part and a resetting device;

the buffer part is movably connected with the blade and comprises a buffer support and buffer teeth, and a clamping groove is formed in the buffer part;

the limiting part comprises a fixed support and a rotating part, and the rotating part is rotationally connected with the support through a pin shaft;

the reset device comprises a buffer part reset device and a rotating part reset device, wherein the buffer part reset device realizes the reset of the buffer part, and the rotating part reset device realizes the reset of the rotating part.

The rotating part resetting device is respectively and fixedly connected with the rotating part and the fixed support.

Under the stable working state of the drill bit, the vibration amplitude of the drill bit in the axial direction is in a small range, and the influence of weak impact generated by the vertical jumping of the drill bit on the cutting teeth is small.

When the drill bit jumps, the buffer part resetting device pushes the buffer part to extend out of the cutter blade, the rotating piece rotates under the pushing of the clamping groove on the buffer part, the rotating range of the rotating piece is not limited in the rotating direction, and meanwhile, the rotating piece resetting device accumulates energy for resetting of the rotating piece. When the pushing action of one clamping groove disappears, the rotating piece returns to the original position under the action of the rotating piece resetting device and prepares for pushing the next clamping groove to rotate.

When the drill bit falls back, the buffer part contacts with the rock at the bottom of the well firstly, the buffer part retracts towards the inside of the blade, the rotating part rotates towards the opposite direction under the pushing of the clamping groove on the buffer part, the rotating part resetting device accumulates energy for resetting of the rotating part, the rotating range of the rotating part is limited in the rotating direction, however, the rotating part is driven by the rotating part resetting device to rotate, the rotating speed of the rotating part is smaller than the moving speed of the buffer part, the rotating part rotates towards the original position direction, and the rotating part cannot play a limiting role in the buffer part.

Therefore, under the stable drilling condition of the drill bit, the rotating piece of the limiting part swings back and forth around the pin shaft under the action of the resetting device, the rotating piece does not limit the buffering part, the buffering part freely contracts and extends relative to the blade under the action of the shaft bottom rock and the resetting device of the buffering part, and the influence of the buffering module on the invasion depth of the cutting teeth can be reduced or avoided.

When the drill bit drills a stratum with non-uniformity or high brittleness, on one hand, the vertical jumping amplitude of the drill bit is increased, on the other hand, the speed of the drill bit in the process of falling back from the highest point to the bottom of the well is gradually increased, and the impact load between the cutting teeth and the rock at the bottom of the well is very large when the cutting teeth reach the bottom of the well. In the application, as the buffering module is arranged on the drill bit, the drill bit falls down, the buffering part on the buffering module is contacted with the rock at the bottom of the well, the buffering part retracts quickly to the blade under the action of the bit pressure, the retracting speed of the blade is increased gradually relative to the bit, the clamping groove on the buffering part retracts in the process, the rotating part can be stirred to rotate by the clamping groove on the buffering part, when the retracting speed of the buffering part exceeds a certain threshold value, the rotating speed of the limiting part to the original position is lower than the retracting speed of the buffering part, the rotating part can not return to the original position and continues to rotate under the action of pushing of the clamping groove, the rotating part stops rotating when contacting with the fixed support, the rotating part is clamped in the clamping groove to fix the buffering part, so that the buffering part can not continue to retract, therefore, the buffering part can be used as the impact load of the drill bit of a support body, and plays a role in weakening or eliminating the impact of the cutting teeth. When the drill bit enters a stable drilling state again and the drill bit slightly jumps, the buffer part resetting device pushes the buffer part to extend out, the brake of the clamping groove on the rotating part is released, the rotating part resetting device enables the rotating part to rotate to the original position, and the buffer part returns to a free telescopic state again.

According to the scheme, the relative height between the buffer module and the cutting teeth of the drill bit is adjusted according to the stratum conditions, the purpose of weakening premature failure of the cutting teeth caused by impact or vibration is achieved, the service life of the drill bit during drilling in a hard stratum is prolonged, and the invasion capacity and the cutting efficiency of the cutting teeth of the drill bit cannot be influenced by the buffer module like a fixed buffer joint during normal drilling.

Preferably, in the free state, the height difference H between the highest point of the buffer part and the highest point of the cutting tooth blade is-D is more than or equal to H and less than or equal to D, and D is the diameter of the cutting tooth.

In the above scheme, the free state refers to the initial position of the buffer module when the drill bit is not in contact with the rock at the bottom of the well. The height difference H between the highest point of the buffering part and the highest point of cutting is-D is more than or equal to H and less than or equal to D, D is the diameter of the cutting tooth, and specifically, three modes are adopted, namely: the highest point of the buffering part is higher than that of the cutting teeth, the highest point of the buffering part is flush with that of the cutting teeth, and the highest point of the buffering part is lower than that of the cutting teeth. The three installation modes can be specifically selected according to different stratum conditions, for example, for a stratum with larger heterogeneity, the installation mode that the highest point of the buffering part is higher than that of the cutting teeth can be selected, so that the buffering part firstly contacts with the rock when the drill bit impacts, and the buffering effect is better achieved.

Preferably, the buffer part includes a buffer tooth and a buffer support, the buffer tooth is embedded and fixed on the buffer support, or the buffer tooth is connected to the buffer support in a freely rotatable manner, or the buffer tooth and the buffer support are integrated.

In the scheme, the buffer teeth can be fixed on the buffer support in the modes of interference fit, welding, threaded connection and the like, and different types of buffer teeth can be conveniently replaced according to the stratum condition and the structural requirement of the drill bit; the buffer tooth can also adopt a structural design integrated with the buffer support, and the processing is convenient; the buffering tooth adopts the mode of rotating the connection on the buffering support, can reduce the friction between buffering tooth and the rock, reduces the wearing and tearing speed of buffering tooth, prolongs the life of buffering module.

Preferably, the buffer teeth are spherical teeth, wedge teeth, conical teeth or PDC teeth.

In the scheme, the buffering effect strength of different tooth profiles is different, so that different tooth profiles can be selected according to requirements. For example, for heavily heterogeneous formations, a dull spherical tooth that is less likely to invade the rock may be selected.

Preferably, the cushion module is mounted on a drill bit in which the PDC cutting structures are combined with other rock breaking structures including a movable rock breaking structure.

In the above scheme, the other movable rock breaking structures may be a roller rock breaking structure, a disc cutter rock breaking structure, an impact rock breaking structure or a combination of at least two rock breaking structures therebetween. And selecting different rock breaking structure combinations according to different stratum conditions and drilling process parameters so as to enhance the adaptability of the drill bit in a specific stratum.

Preferably, the buffer part returning device is a compression spring, and the rotating member returning device is a torsion spring.

In the above scheme, the compression spring and the torsion spring are simple in structure, convenient to install and high in control sensitivity.

Compared with the prior art, the invention has the beneficial effects that:

1. a buffer module on the drill bit may automatically adjust the height between the cutting teeth based on a threshold value of impact velocity. When the drill bit drills normally and stably, the buffer part extends out and retracts into the blade normally, the invasion capacity of the cutting teeth is not influenced, and the faster mechanical drilling speed of the drill bit is kept; when the drill bit is subjected to a large-amplitude impact load, if the retraction speed of the buffering part exceeds a certain threshold value, the rotating part clamps the buffering part and cannot continue to retract into the blade under the action of the fixed support, so that the buffering part can effectively absorb the impact load of the drill bit, the failure of the cutting teeth of the drill bit caused by large impact is avoided, and the service life of the drill bit is prolonged. After the impact, the buffer part returns to the normal extending and retracting movement state again.

2. Simple manufacture and high sensitivity.

3. Besides revolving around the axis of the buffer module, the buffer teeth can also rotate around the axis of the buffer teeth, so that the friction between the buffer teeth and the stratum can be reduced, and the service life of the buffer module is prolonged.

Drawings

The invention will be described by way of specific embodiments and with reference to the accompanying drawings, in which

FIG. 1 is a schematic structural diagram of a drill bit capable of implementing an adaptive buffering function according to an embodiment of the present invention;

FIG. 2 is a schematic structural diagram of a buffer module;

FIG. 3 is a schematic view of a limiting portion;

FIG. 4 is a schematic view of a buffer portion;

FIG. 5 is a free state diagram of a buffer module;

FIG. 6 is a schematic view of a buffer module in an extended state;

FIG. 7 is a schematic view of the buffer module in a retracted state;

FIG. 8 is a schematic diagram of the buffer module in a jammed state;

FIG. 9 is a schematic view of a PDC tooth for the buffer tooth;

FIG. 10 is a schematic view of a flat-set of a spherical PDC tooth as a buffer tooth;

FIG. 11 is a schematic view of the buffer teeth being fixed to the buffer base in an interference manner;

FIG. 12 is a schematic view of a structure having a plurality of buffer teeth on a buffer base;

FIG. 13 is a schematic view of a structure in which the buffer teeth are ring-shaped teeth;

FIG. 14 is a schematic view of a configuration in which the buffer teeth are rotatable teeth;

FIG. 15 is a schematic view of the buffer module mounted position on the blade relative to the cutting teeth;

FIG. 16 is a schematic view of the bumper module mounted on the extended support of the blade;

FIG. 17 is a schematic view of a blade extension support in the form of a cantilever beam;

FIG. 18 is a schematic view of the blade extension support being an interface between two adjacent blades;

FIG. 19 is a schematic diagram of a rock breaking structure with a movable structure of a roller cone.

1-a blade; 101 a first blade; 102 a second blade; 103 a third blade; 104 a fourth blade; 105 a fifth blade; 106 fixing a buffer module; 2-cutting teeth; 3-a buffer module; 4-a buffer section; 401 a buffer seat; 402 buffer teeth; 4021 an outer cover plate; 4022A screw; 4023 a seal ring; 4024 wear-resistant support; 403 card slot; 404 a limiting groove; 5-a limiting part; 501, fixing a support; 5021 rotating the rotating piece; 5022 a lower rotating part; 503 a pin shaft; 504 a jamming end face; 6 buffer reset device; 7 rotating member resetting means; 8, limiting pins; 9 a bit body; 110 blade extension supports; and breaking the rock structure by using the 111 roller cone.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.

In the description of the embodiments of the present invention, it should be noted that the indication of the orientation or the positional relationship is based on the orientation or the positional relationship shown in the drawings, or the orientation or the positional relationship which is usually placed when the product of the present invention is used, or the orientation or the positional relationship which is usually understood by those skilled in the art, or the orientation or the positional relationship which is usually placed when the product of the present invention is used, and is only for the convenience of describing the present invention and simplifying the description, but does not indicate or imply that the indicated device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and therefore, cannot be understood as limiting the present invention. Furthermore, the terms "first" and "second" are used merely to distinguish one description from another, and are not to be construed as indicating or implying relative importance.

In the description of the embodiments of the present invention, it should be further noted that the terms "disposed" and "connected" are to be interpreted broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected, unless explicitly stated or limited otherwise; may be directly connected or indirectly connected through an intermediate. The specific meanings of the above terms in the present invention can be understood in specific cases by those skilled in the art; the drawings in the embodiments are used for clearly and completely describing the technical scheme in the embodiments of the invention, and obviously, the described embodiments are a part of the embodiments of the invention, but not all of the embodiments. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

Fig. 1 is a schematic view of a drill bit according to an embodiment of the present invention. A diamond drill bit capable of realizing a self-adaptive buffering function comprises a drill bit body 9 and blades 1 extending out of the drill bit body 9, wherein cutting teeth 2 are arranged on the blades 1, and at least one buffering module 3 is arranged on the drill bit.

As shown in fig. 2, which is a schematic structural diagram of the buffer module 3, the buffer module 3 includes a buffer portion 4, a limiting portion 5, a buffer portion reset device 6, a rotating member reset device 7 and a limiting pin 8, the buffer portion reset device 6 realizes the reset of the buffer portion 4, and the rotating member reset device 7 realizes the reset of the limiting portion 5.

Wherein, form the swing joint between buffer 4 and the blade 1, form the fixed connection between the fixed bolster 501 of spacing portion 5 and the blade 1.

Fig. 3 is a schematic structural view of the limiting portion 5. The limiting portion 5 includes a fixed support 501, an upper rotating member 5021, and a lower rotating member 5022, the upper rotating member 5021 and the lower rotating member 5022 are rotatably connected to the fixed support 501 through a pin 503, and a rotating member resetting device 7 is disposed between the upper rotating member 5021 and the lower rotating member 5022 and the pin 503, referring to fig. 2. When the lower rotating member 5022 rotates around the pin 503, the upper end surface of the lower rotating member 5022 is obstructed by the blocking end surface 504 on the fixed support 501 in the process that the lower rotating member 5022 rotates towards the upper rotating member 5021, and the optimal position is that the upper end surface of the lower rotating member 5022 is horizontal.

Specifically, the rotating member returning device 7 is a torsion spring.

Fig. 4 is a schematic structural view of the buffer part 4. Specifically, the buffer portion 4 includes a buffer base 401, a buffer tooth 402, a catching groove 403, and a stopper groove 404. Among other things, the buffer teeth 402 may be spherical teeth, wedge teeth, conical teeth, or PDC teeth. The stopper groove 404 is connected to the stopper pin 8, and functions to prevent the buffer portion from falling off.

The free state refers to the initial position of the buffer module 3 when the drill bit is not in contact with the rock at the bottom of the well, and when the buffer module 3 is in the free state, the height difference H between the highest point of the buffer part 4 of the buffer module 3 and the highest point of the cutting edge of the cutting tooth 2 is as follows: d is more than or equal to H and less than or equal to D, and D is the diameter of the cutting tooth 2.

In the free state, the height difference between the highest point of the buffer tooth 402 of the buffer portion 4 and the highest point of the cutting tooth 2 is H, H may be greater than zero, less than zero, or equal to zero, and fig. 5 shows a manner in which the highest point of the buffer tooth 402 is higher than the highest point of the cutting tooth 2 in the free state, that is, H is greater than zero. In the free state, the upper rotating member 5021 is in a horizontal state, and the lower rotating member 5022 is below the upper rotating member 5021 but is not in contact with the slot 403.

As shown in fig. 6, the relief portion 4 is in the blade-protruding state. Under the pushing action of the buffer part resetting device 6, the buffer part 4 extends out of the blade 1, the clamping groove 403 in the buffer part 4 is in contact with the upper rotating piece 5021 of the limiting part 5, the upper rotating piece 5021 is pushed to rotate clockwise, the lower rotating piece 5022 is driven to rotate clockwise, and meanwhile, the rotating piece resetting device 7 accumulates energy. As the latch slot 403 continues to move downward without contacting the upper rotating member 5021, the energy accumulated in the rotating member resetting device 7 is released, so that the upper rotating member 5021 and the lower rotating member 5022 rotate counterclockwise and return to the free state, and preparation is made for the next contact between the latch slot 403 and the upper rotating member 5021.

Specifically, the buffer returning device 6 may be a compression spring or a disc spring.

As shown in fig. 7, the cushioning portion 4 is in the retracted blade state. When the buffer gear 402 receives the acting force of the rock at the bottom of the well, the rock pushes the buffer gear 402 to retract into the blade 1, the clamping groove 403 is in contact with the upper rotating member 5021 and pushes the upper rotating member 5021 and the lower rotating member 5022 to rotate anticlockwise, and meanwhile, the buffer part resetting device 6 is compressed to accumulate energy. In the retraction process of the buffer portion 4, when the latch slot 403 is disengaged from the upper rotating member 5021, the upper rotating member 5021 and the lower rotating member 5022 rotate clockwise under the action of the rotating member resetting device 7, and return to the free state.

As shown in fig. 8, the position-limiting portion 5 and the buffering portion 4 are in the retracted blocking state. When the drill bit is subjected to a large impact from the ground, the buffer part 4 retracts into the blade 1 at a rapid speed, and the upper rotating piece 5021 rotates counterclockwise under the pushing action of the clamping groove 403. When the contact action between one of the slots 403 of the buffer portion 4 and the upper rotating member 5021 is lost, the upper rotating member 5021 and the lower rotating member 5022 rotate to the free state (i.e., rotate clockwise in fig. 8) under the action of the rotating member returning device 7, however, when the speed of returning the upper rotating member 5021 and the lower rotating member 5022 to the free state is less than the retracting speed of the buffer portion 4, the lower rotating member 5022 is located between two adjacent slots 403, and the upper rotating member 5021 and the lower rotating member 5022 are caught by the slots 403 without returning to the original positions and rotate counterclockwise along with the retracting movement of the buffer portion 4. Referring to fig. 3, when the upper end surface of the lower rotating member 5022 rotates to contact with the blocking end surface 504 of the fixed support 5, the lower rotating member 5022 stops rotating and blocks the slot 403 to prevent the buffer part 4 from retracting further, so that the buffer part 4 can absorb the impact load and achieve the buffering effect. Once the impact action on the drill bit disappears, the buffer part resetting device 6 releases compression energy to push the buffer part 4 to extend, so that the blocking between the clamping groove 403 and the lower rotating piece 5022 is released, and the lower rotating piece 5022 and the upper rotating piece 5021 recover to a free state under the action of the rotating piece resetting device 7 to prepare for the next impact.

The buffer teeth 402 may be embedded and fixed on the buffer seat 401 in the form of spherical teeth, conical teeth, wedge-shaped teeth, PDC teeth, etc. As shown in fig. 9, the buffer teeth 402 take the form of PDC teeth.

The buffering teeth 402 can be installed in a mode that the spherical teeth 402 can be used for buffering the teeth and can also be installed in a mode that the spherical PDC teeth are embedded flatly, as shown in fig. 10, the abrasion resistance of the diamond and the blunt characteristic of the spherical teeth are fully utilized, the impact load absorption capacity is high, and the abrasion resistance is further improved. According to the requirement for the buffering effect, the buffering teeth 402 can also be embedded in a conical ball PDC (polycrystalline Diamond compact) tooth or a pointed conical PDC tooth.

The buffer teeth 402 may be fixed on the buffer base 401 by interference fit, welding, screwing, or the like, as shown in fig. 11, which is a schematic structural diagram that the buffer teeth 402 are fixed on the buffer base 401 by interference fit.

There may be one or more buffer teeth 402 on the buffer base 401, as shown in fig. 12, which is a schematic view of a plurality of buffer teeth 402 on the buffer base 401.

The buffer teeth 402 may have other irregular tooth shapes, as shown in fig. 13, and the buffer teeth 402 are annular teeth.

The damping teeth 402 may also be free to rotate relative to the damping mount 401. One configuration is shown where the damper teeth 402 are free to rotate, as shown in fig. 14. Rotatable damping teeth 402 include outer cover plate 4021, screw 4022, wear support 4024, and seal ring 4023. Compared with the buffer tooth 402 fixedly embedded on the buffer seat 401, the buffer tooth 402 capable of rotating freely can reduce the rapid wear failure between the buffer tooth 402 and the rock caused by friction, and prolong the service life of the buffer tooth 402.

For the installation position of the buffer module 3 on the drill bit, the buffer module 3 may be installed on the blade where the cutting tooth is located, or may be installed on an independent blade of the drill bit. Taking the five-blade drill bit in fig. 15 as an example, the second blade 102 in fig. 15 is the buffer module 3 installed on the independent blade of the drill bit.

For the case that the cushion module 3 is installed on the blade where the cutting tooth is located, there are several installation methods, taking the five-blade drill in fig. 15 as an example: firstly, the buffer module 3 is arranged behind the cutting teeth on the blade, and as shown in fig. 15, the buffer module 3 is arranged on the fourth blade 104; a buffer module 4 is arranged in front of the cutting teeth on the blade, and as shown in fig. 15, a buffer module 3 is arranged on a third blade 103; ③ the buffer module 3 is installed in parallel with the cutting teeth, as shown in fig. 15, the buffer module 3 is installed on the first blade 101. The above installation modes can be one installation mode or a combination of several installation modes. In addition, the above installation method may be installed in combination with a fixed buffer module, such as the fixed buffer module 106 installed on the fifth blade 105 in fig. 15, and the fixed buffer module 106 may be a tapered tooth, a spherical tooth, or other blunt teeth.

The damping module 3 may also be mounted on the blade extension support 110 as shown in fig. 16. In this embodiment, the blade extension support 110 may extend towards the front end of the blade or towards the rear end of the blade, and fig. 16 shows a schematic view that the blade extension support 110 extends towards the front end of the blade 1. Blade extension support 110 may or may not be attached to the bit body, as shown in fig. 16, i.e., blade extension support 110 and blade 1 form a cantilever beam structure, as shown in fig. 17. The blade extension support 110 may be a connection between two adjacent blades, such as the blade extension support 110 between the first blade 101 and the second blade 102 as shown in fig. 18.

The cushion module may also be mounted on a drill bit having a PDC cutting structure combined with other rock breaking structures, including movable rock breaking structures. A composite bit with a rock breaking cone structure 111 combined with fixed PDC teeth 2 as shown in fig. 19.

The embodiments of the present disclosure described above and illustrated in the drawings do not limit the scope of the present disclosure, but rather cover the scope of the present disclosure by the appended claims and their legal equivalents. Any equivalent embodiments are within the scope of the present disclosure. Indeed, various modifications of the disclosure in addition to those shown and described herein, such as alternative useful combinations of the elements described, will be apparent to those skilled in the art from the foregoing description. Such modifications and embodiments are within the scope of the following claims and equivalents.