Drill bit for hard rock stratum and vertical shaft drilling machine with same

Abstract

The invention provides a drill bit for hard rock stratum.The drill bit comprises a cutter head assembly, the cutter head assembly comprises a bottom plate and cutters installed on the bottom plate, and the cutters comprise a pair of center hobs, a pair of inner ring cutters located on the outer sides of the center hobs and a plurality of outer ring cutters; the center hobs are close to the center of the bottom plate and symmetrically arranged on the two sides of the center, and the bottom plate comprises a bottom plate body used for installing an outer ring cutter and an installation groove formed in the bottom plate body and used for installing the center hobs and an inner ring cutter. The central hob, the inner ring cutter and the plurality of outer ring cutters are respectively positioned in different radial directions of the bottom plate, and horizontal sections of trajectory lines of all the cutters are positioned in the same plane. Through the design of the cutterhead assembly, under the special environment of a hard rock stratum, the stability and rock breaking efficiency of the drill bit in the construction process are improved, and the service life of the cutterhead is prolonged.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of tunneling equipment, and particularly relates to a drill bit for hard rock stratum and a shaft drill rig with the same. BACKGROUND

[0002] With the development of national economy, there is a strong demand for deep shaft construction in the fields of gold mines, copper mines, iron mines and phosphate mines, and especially the secondary shaft construction in underground tunnels is limited by limited construction space. At present, drilling method is usually used for construction. The drilling method is a relatively safe shaft construction method of "drilling without lowering into the well". The drilling method provides power for the ground, and the lower part uses a drill bit to drill.

[0003] Generally, different types of drill bits are selected for different geological construction projects, otherwise the drill bit is prone to damage, the drill bit maintenance cycle is long, the construction efficiency is reduced, and the cost of the drill is high.

[0004] Therefore, it is necessary to design a drill bit for hard rock stratum and a shaft drill rig with the same to solve one of the above problems. SUMMARY

[0005] The present application provides a drill bit for hard rock stratum and a shaft drill rig with the same. The drill bit for hard rock stratum can improve the stability and wear resistance of the drill bit during drilling.

[0006] In order to achieve the above purpose, the technical scheme provided by the present application is as follows: The present application provides a drill bit for hard rock stratum, which comprises a cutter head assembly, the cutter head assembly comprises a bottom plate and cutters mounted on the bottom plate, wherein the cutters comprise a pair of center rollers, a pair of inner ring cutters located outside the center rollers, and a plurality of outer ring cutters, the center rollers are close to the center of the bottom plate and are symmetrically arranged on both sides of the center, the bottom plate comprises a bottom plate body for mounting the outer ring cutters and a mounting groove arranged on the bottom plate body for mounting the center rollers and the inner ring cutters, the center rollers, the inner ring cutters and the plurality of outer ring cutters are respectively located at different radial directions of the bottom plate, and the horizontal segments of the trajectory lines of all the cutters are in the same plane.

[0007] Further, the pair of center rollers are arranged in transverse intervals, the pair of inner ring cutters are respectively located on the outer sides of the pair of center rollers in the longitudinal direction, and the inner ring cutters are centrally symmetrically arranged with the center of the bottom plate.

[0008] Further, the outer ring cutters comprise a pair of first cutters adjacent to the center cutter, a pair of second cutters outside the inner ring cutters, in the radial direction of the bottom plate, the radius of the circumference of the first cutters is smaller than the radius of the circumference of the second cutters, the cutting edges of the first cutters and the second cutters are inclined inward and downward, and the included angle is 10-20°.

[0009] Further, the outer ring cutters further comprise a pair of third cutters and a fourth cutter at the edge of the bottom plate, the third cutters and the fourth cutter are spaced apart along the circumferential direction of the bottom plate, in the radial direction of the bottom plate, the cutting edges of the third cutters and the fourth cutter are inclined outward and upward, and the included angle is 30-40°.

[0010] Further, the bottom plate and the cutters and the cutter mounting base form a cutter head, the horizontal projection of the center of gravity of the cutter head is at the center of the bottom plate.

[0011] Further, the cutter head assembly further comprises a fixing device fixedly connected to the side of the bottom plate away from the cutters, the drill bit comprises a slag discharge channel penetrating in the up-down direction, a high-pressure gas cavity outside the slag discharge channel, the slag discharge channel comprises a slag discharge bend outwardly inclined and penetrating through the fixing device, and the cutter head assembly further comprises a counterweight cavity spaced apart from the slag discharge bend.

[0012] Further, the cutter head assembly further comprises a stop block arranged at the end of the slag discharge channel.

[0013] Further, the cutter head assembly further comprises a plurality of back flushing ports arranged on the bottom plate and communicating with the slag discharge channel, the back flushing ports are arranged at the edge of the bottom plate and spaced apart along the circumferential direction of the bottom plate, and the cutter head assembly further comprises a ring plate arranged outside the back flushing ports.

[0014] Further, the drill bit further comprises at least one set of guide modules fixedly connected to the side of the cutter head assembly away from the cutters, the guide module comprises a guide device fixedly connected to the cutter head assembly, a connecting device fixedly installed on the side of the guide device away from the cutter head assembly, a fixing member for fixing the guide device and the connecting device, and a plurality of connecting bolts, the connecting bolts comprise forward bolts and reverse bolts, and the forward bolts and the reverse bolts are symmetrically arranged.

[0015] Further, the slag discharge channel further comprises a lower slag discharge pipe inside the guide device adjacent to the fixing device, the lower slag discharge pipe communicates with the slag discharge bend, and a plurality of mixed gas holes are formed in the lower slag discharge pipe.

[0016] Further, the fixing member is in interference fit with the flanges of the guide device and the connecting device.

[0017] Further, the guiding device comprises a guiding body and at least two guide rollers mounted on the side of the guiding body; the guide rollers are arranged in a central symmetry with the guiding body, and the distance between the guide rollers and the guiding module is less than the radial dimension of the guide rollers.

[0018] Further, the guide roller comprises a mounting structure with a lubricating cavity and a grease compensation cavity connected in communication, an outer cylinder structure, at least one bearing structure mounted in the lubricating cavity and used for rotationally connecting the mounting structure and the outer cylinder structure, and a pressure balance structure arranged in the compensation cavity to apply pressure to the bottom wall of the compensation cavity away from the lubricating cavity, so that the internal pressure of the compensation cavity is not less than the external pressure.

[0019] Further, the drill bit further comprises a transition module used for fixedly connecting the guiding module and the drill rod, and the slag discharge channel extends to the upper end of the transition module.

[0020] The application also provides a shaft drill, which comprises the drill bit for hard rock stratum.

[0021] Compared with the related art, the drill bit for hard rock stratum has the advantages that through the design of the cutter head assembly, the stability in the construction process, the rock breaking efficiency, and the service life of the cutter head are improved in the special environment of the hard rock stratum. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is a cross-sectional structural schematic diagram of the drill bit of one embodiment of the drill bit for hard rock stratum.

[0023] Figure 2 is Figure 1 a bottom view structural schematic diagram of the cutter head assembly in the drill bit for hard rock stratum.

[0024] Figure 3 is Figure 1 a cross-sectional structural schematic diagram of the guiding device in the drill bit for hard rock stratum.

[0025] Figure 4 is Figure 3 an enlarged view of the local structure at A in the drill bit for hard rock stratum.

[0026] Figure 5 is Figure 3 a cross-sectional view of the guide roller in the drill bit for hard rock stratum.

[0027] Figure 6 is Figure 5 an enlarged view of the local structure at B in the drill bit for hard rock stratum.

[0028] Figure 7 is Figure 5 an enlarged view of the local structure at C in the drill bit for hard rock stratum.

[0029] Figure 8 isFigure 1 Side view of the middle fixing member.

[0030] Figure 9 is Figure 1 Bottom view of the middle transition module.

[0031] Wherein, 20-cutter assembly, 201-bottom plate, 2011-bottom plate body, 2012-mounting groove, 202-cutter, 2021-center hob, 2022-inner ring cutter, 2023-first cutter, 2024-second cutter, 2025-third cutter, 2026-fourth cutter, 203-fixing device, 204-counterweight cavity, 205-stop block, 206-back flushing port, 207-ring plate, 10-guide device, 101-guide body, 102-guide roller, 1-mounting structure, 11-mounting shaft, 12-lubrication cavity, 13-cover, 131-oil injection hole, 132-hole plug, 141-first sealing ring, 142-second sealing ring, 15-floating plug, 16-compensation cavity, 17-plug, 171-elastic ring, 18-retaining ring, 181-fixing ring, 182-adjusting ring, 2-outer cylinder structure, 21-inserted tooth, 3-bearing structure, 31-first bearing, 32-second bearing, 4-pressure balance structure, 41-piston, 42-elastic member, 43-sealing ring, 103-mounting part, 1031-first mounting hole, 1032-second mounting hole, 104-mounting seat, 1041-fixing part, 1042-connecting part, 105-stiffener, 106-slag discharge channel, 1061-slag discharge bend, 1062-mixed gas hole, 107-high pressure gas cavity, 108-counterweight ring, 109-cover plate, 1091-clamp block, 30-connecting device, 40-fixing member, 50-transition module, 51-internal hexagonal spline joint. DETAILED DESCRIPTION

[0032] In order for those skilled in the art to better understand the technical solutions in the present application, the technical solutions 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 only part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor should be within the scope of protection of the present application.

[0033] It should be noted that the terms "upper", "lower", etc. indicate the orientation or positional relationship shown in the drawings, and are only used to facilitate the description of the present application, and do not indicate or imply that the device must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the scope of protection of the present application. Specifically, in the present application, the direction toward the ground is downward, and other orientation descriptions are defined based on the "upper" and "lower" as the reference.

[0034] In various drawings of the present application, certain dimensions of structures or parts are exaggerated relative to other structural parts for purposes of illustration, and thus, are merely intended as illustrative structures for understanding the basic structure of the present application.

[0035] The present application provides a drill bit for hard rock formation and a shaft drill with the same, as shown in Figure 1 The drill bit is arranged at the lower end of the drill rod of the shaft drill, and the shaft drill controls the drill bit to perform drilling operation by controlling the drill rod.

[0036] As shown in Figures 1 to 2 The drill bit includes a cutter disc assembly 20 and at least one set of guide modules fixedly connected with the cutter disc assembly 20, wherein the guide module includes a guide device 10 connected with the cutter disc assembly 20 and a connecting device 30 connected with the guide device 10, and the drill bit further includes a transition module 50 fixedly connecting the guide module with the drill rod. In the present application, the drill bit is provided with three sets of guide modules, and different numbers of guide modules can be selected according to different drilling operations to change the height of the drill bit.

[0037] The cutter disc assembly 20 includes a bottom plate 201 and cutters 202 mounted on the bottom plate 201. The bottom plate includes a bottom plate body 2011 and a mounting groove 2012 located at the middle position of the bottom plate body 2011, so as to mount cutters 202 of different mounting modes in the bottom plate body 2011 and the mounting groove 2012 respectively, and to ensure that the horizontal segments of the trajectory lines of all the cutters 202 are in the same plane.

[0038] Specifically, the cutters 202 include a pair of center rollers 2021 located in the mounting groove 2012, a pair of inner ring cutters 2022 located outside the center rollers 2021, and a plurality of outer ring cutters. The center rollers 2021 are close to the center of the bottom plate 201 and symmetrically arranged on both sides of the center. The center rollers 2021, the inner ring cutters 2022 and the plurality of outer ring cutters are respectively located at different radial directions of the bottom plate 201, and the horizontal segments of the trajectory lines of all the cutters 202 are in the same plane. The layout and design of the cutters 202 of the drill bit in the present application improve the rock breaking efficiency of the drill bit, improve the stability during rock breaking of the drill bit, and prolong the service life of the drill bit.

[0039] For the convenience of the following description, the length direction of the drill bit is the axial direction, and the extension direction of the bottom plate 201 is the circular plane. Among them, the arrangement direction of the pair of center rollers 2021 is the transverse direction, the direction perpendicular to the transverse direction is the longitudinal direction, the symmetry point of the center rollers 2021 is the circular point of the bottom plate 201, and other directions are based on this.

[0040] As shown in Figure 2As shown, a pair of the center cutters 2021 are arranged along the transverse diameter line, and the center cutters 2021 are positive cutters, which facilitate breaking the rock near the center of the bottom plate 201.

[0041] A pair of the inner ring cutters 2022 are arranged in the mounting groove 2012 and are located on the vertical outer side of the pair of the center cutters 2021, that is, the inner ring cutters 2022 are arranged in a central symmetry with the center of the bottom plate 201, and if the bottom plate 201 is divided into four quadrants, the pair of the inner ring cutters 2022 are respectively located in the first quadrant and the third quadrant.

[0042] The center cutters 2021 and the inner ring cutters 2022 are both installed by using the saddle type cutter holder, and since the shoe type cutter holder is high, the center cutters 2021 and the inner ring cutters 2022 are installed in the mounting groove 2012 to ensure that the horizontal sections of the trajectory lines of the center cutters 2021, the inner ring cutters 2022 and the outer ring cutters are all in the same plane.

[0043] The outer ring cutters are arranged on the bottom plate body 2011, and the outer ring cutters include a pair of first cutters 2023 adjacent to the center cutters 2021 and a pair of second cutters 2024 located on the outer side of the inner ring cutters 2022, and the first cutters 2023 and the second cutters 2024 undertake the main rock breaking task.

[0044] In the radial direction of the bottom plate 201, the radius of the circle on which the first cutters 2023 are located is smaller than the radius of the circle on which the second cutters 2024 are located, that is, the first cutters 2023 are closer to the center of the bottom plate 201 than the second cutters 2024, the first cutters 2023 are respectively located in the second quadrant and the fourth quadrant, and the second cutters 2024 are respectively located on the vertical diameter line, and the first cutters 2023 and the second cutters 2024 are uniformly arranged to balance the load of the cutters 202 and reduce the vibration of the cutters 202 in the construction.

[0045] The blade edges of the first cutters 2023 and the second cutters 2024 are inclined inward and downward, and the included angle is 10°-20°, which can avoid the swing of the cutter head during the rotation of the cutters 202 and also can realize smooth transition at the combined part of the bottom plate body 2011 and the mounting groove 2012. Preferably, the included angle is 15°, which can form a larger flat excavation area.

[0046] Further, the outer ring cutter further comprises a pair of third cutters 2025 and a fourth cutter 2026 located at the edge of the bottom plate 201, the third cutters 2025 are located in the first quadrant and the third quadrant, and the cutting edges of the third cutters 2025 and the fourth cutter 2026 are inclined outward and upward in the radial direction of the bottom plate 201, and the included angle is 30-40°, the third cutters 2025 and the fourth cutter 2026 are both located relative to the edge of the bottom plate body 2011 and are inclined outward, which is beneficial to the contact of the cutter 202 with the well wall, further strengthens the guiding effect of the drill bit and has the effect of trimming the rock of the well wall, and preferably the included angle is 35°.

[0047] The fourth cutter 2026 has three pairs in total and is uniformly arranged along the circumference of the bottom plate body 2011, so that each direction of the cutter 202 can contact the well wall.

[0048] Further, the cutters 202 and the cutter seats form a cutter disc, the barycenter of the cutter disc is horizontally projected on the center position of the bottom plate 201, and when the cutter disc rotates, the cutter disc reaches a state of dynamic balance, the drill bit shakes little, the impact load is small, and the service life of the cutter 202 and the like can be prolonged.

[0049] Specifically, taking the center of the bottom plate 201 as the coordinate zero point, the transverse direction of the bottom plate as the X axis and the vertical direction as the Y axis, the product sum of the distances between the barycenter positions of each cutter and cutter seat and the X and Y axes is zero, as shown in the following formula, wherein Gi is the gravity of the cutter, and gi is the gravity of the cutter seat. .

[0050] As shown in Figure 1 , the drill bit comprises a residue discharge channel 106 penetrating in the up-down direction and a high-pressure gas cavity 107 outside the residue discharge channel 106, the residue discharge channel 106 and the high-pressure gas cavity 107 in the guiding device 10 are part of the above-mentioned residue discharge channel and high-pressure gas cavity, the high-pressure gas cavity 107 is arranged adjacent to the residue discharge channel 106, which facilitates the mixing of high-pressure air from the high-pressure gas cavity 107 with the mud to form a low-density fluid, drives the mud containing rock cuttings to be discharged upward from the bottom of the well to the ground through the residue discharge channel 106, and avoids the accumulation of the bottom of the well to cause the drill bit to be blocked or the efficiency to be reduced.

[0051] The cutter disc assembly 20 further comprises a plurality of backflow ports 206 arranged on the bottom plate 201 and arranged at the edge of the bottom plate 201 along the circumference of the bottom plate 201, the backflow ports 206 flow a small amount of mud back to the vicinity of the cutter disc, avoiding the formation of a vacuum environment around the cutter disc.

[0052] The cutter head assembly 20 further comprises a fixing device 203 fixedly connected to the bottom plate 201 away from the cutting tool, and the slag discharge channel 106 comprises a slag discharge curve 1061 inclined outwardly and penetrating through the fixing device 203. Due to the offset design of the slag discharge curve 1061 relative to the center of the bottom plate 201 and the asymmetric structure of the bottom plate 201, the cutter head assembly 20 further comprises a counterweight cavity 204 arranged in space with the slag discharge curve 1061. The counterweight cavity 204 is in a cylindrical structure, and the specific position and size of the counterweight cavity 204 are designed according to the position of the gravity center of the cutter head after the other structures of the cutter head are completely designed.

[0053] The cutter head assembly 20 further comprises a stop block 205 arranged at the end of the slag discharge curve 1061 to prevent large slag blocks from entering the slag discharge curve 1061.

[0054] The other positions of the fixing device 203 are counterweight rings for increasing the weight of the drill bit. The counterweight rings are made of the same material and in the same way as the counterweight rings in the guide device 10, which will be described in detail later.

[0055] As a preferred embodiment of the present application, as shown in Figure 1 and Figure 3 The guide module is fixedly connected to the side of the cutter head assembly 20 away from the cutting tool, and the guide module comprises a guide device 10 fixedly connected to the cutter head assembly 20, a connecting device 30 fixedly installed on the side of the guide device 10 away from the cutter head assembly 20, a fixing member 40 for fixing the guide device 10 and the connecting device 30, and a plurality of connecting bolts. The connecting bolts comprise forward bolts and reverse bolts, which are symmetrically arranged, that is, the forward bolts are locked in the clockwise direction, and the reverse bolts are locked in the counterclockwise direction, which are opposite in direction to achieve self-locking effect. During the working process of the drill bit, the bolts are less likely to fall off.

[0056] In the embodiment, the slag discharge channel 106 further comprises a lower slag discharge pipe in the guide device 10 adjacent to the fixing device 203. The lower slag discharge pipe is in communication with the slag discharge curve 1061, and a plurality of mixed gas holes 1062 are formed in the lower slag discharge pipe, which can quickly meet the requirement of the critical condition of the gas lift reverse circulation mud submergence ratio, and is beneficial to the mixing of high-pressure air and mud to form low-density fluid.

[0057] As shown in Figure 3As shown, the guide device 10 comprises a guide body 101, at least two guide rollers 102 mounted on the side of the guide body 101, mounting portions 103 arranged at the two axial ends of the guide body 101 for mounting upper and lower drilling tools, mounting seats 104 arranged in the middle of the guide body 101 for mounting the guide rollers 102; the guide rollers 102 are arranged in central symmetry with the guide body 101, the distance between the guide rollers 102 and the guide body 101 is less than the radial dimension of the guide rollers 102, so that the overall structure of the guide device 10 is relatively compact, the center of gravity is located at the center position, and the stability and service life of the guide device 10 are improved.

[0058] The mounting portions 103 are fixed to the two axial ends of the guide body 101, and are arranged on the side of the guide body 101 in axial symmetry with the guide body 101, wherein the mounting portion 103 on one side of the guide body 101 is provided with a first mounting hole 1031, and the mounting portion 103 on the other side of the guide body 101 is provided with a second mounting hole 1032, the inner diameters of the first mounting holes 1031 are the same, and the inner diameters of the second mounting holes 1032 are different and are provided with steps, that is, the guide device 10 is fixed by different bolts.

[0059] Further, the mounting seat 104 comprises a fixed portion 1041 fixed to the side of the guide body 101, and a connecting portion 1042 fixedly connected with the fixed portion 1041, the fixed portion 1041 extends along the axial direction of the guide device 10, and the connecting portion 1042 extends along the radial direction of the guide device 10, and the connecting portion 1042 is provided with a mounting hole for mounting the guide roller 102 so that the guide roller 102 is arranged in spaced apart relationship with the guide body 101.

[0060] In this embodiment, the mounting seat 104 is T-shaped, the thickness of the fixed portion 1041 is greater than the thickness of the connecting portion 1042, and during the drilling and tripping processes, the guide roller 102 can bear a larger axial load, and the stability of the guide device 10 during the drilling process is improved.

[0061] In this application, the axial dimension of the guide roller 102 is not greater than the distance between the guide roller 102 and the mounting portion 103, the volume of the guide roller 102 is moderate, and the stability of the guide roller 102 during rotation is improved.

[0062] In the radial direction of the guide body 101, the edge of the guide roller 102 exceeds the edge of the guide body 101, so that the outer cylinder structure 2 of the guide roller 102 is in contact with the well wall, and the friction between the outer cylinder structure 2 and the well wall drives the outer cylinder structure 2 to rotate, reduces the resistance between the guide roller 102 and the well wall, and further reduces the torque when the guide device 10 rotates.

[0063] In this embodiment, the guide roller is provided with six guide rollers, which are equidistantly arranged on the side of the guide body 101 along the circumferential direction of the guide body 101.

[0064] Specifically, as shown in Figures 5 to 7 The guide roller 102 includes a mounting structure 1 for fixing the guide roller 102 and other components, an outer cylinder structure 2, at least one bearing structure 3 for rotatingly connecting the mounting structure 2 and the outer cylinder structure 2, and a pressure balance structure 4 arranged inside the mounting structure 2. The above-mentioned structures cooperate with each other to isolate the external mud from entering the inside of the mounting structure 2, avoid the risk of pollution and even corrosion of the inside of the mounting structure 2 by the mud, reduce the maintenance cost, and improve the efficiency of construction.

[0065] For the convenience of understanding and description, the axial direction of the mounting structure 1 and the outer cylinder structure 2 is defined as the length direction of the guide roller 102, that is, the same as the axial direction of the guide roller 102, and other directions are arranged correspondingly with the axial direction.

[0066] Part of the mounting structure 1 is located inside the outer cylinder structure 2. Specifically, the mounting structure 1 includes a mounting shaft 11 which extends in the axial direction, and the middle part of the mounting shaft 11 is located inside the outer cylinder structure 2. The length of the mounting shaft 11 in the axial direction exceeds the outer cylinder structure 2, and the mounting shaft 11 is used to mount the guide roller 102 on other structures of the guide device 10.

[0067] The mounting structure 11 is provided with a lubricating cavity 12 for accommodating the bearing structure 3, and the lubricating cavity 12 extends in the axial direction and is located on the side of the mounting shaft 11. Preferably, the lubricating cavity 12 is formed between the mounting shaft 11 and the outer cylinder structure 2, which facilitates the cooperation of the bearing structure 3 with the outer cylinder structure 2 and the mounting structure 1, respectively.

[0068] The mounting structure 1 further includes a cover 13 for covering the end of the lubricating cavity 12, an oil injection hole 131 penetrating through the cover 13 to communicate the inside and outside of the lubricating cavity 12, and a hole plug 132 for plugging the oil injection hole 131. In the initial installation stage and subsequent maintenance stage of the guide roller 102, the lubricating cavity 12 is filled with oil through the oil injection hole 131, and the oil injection hole 131 is plugged by the hole plug 132. In this embodiment, the hole plug 132 is a bolt plug, which is convenient to install and remove, and will not fall off due to construction vibration.

[0069] The cover 13 away from the pressure balancing structure 4 is connected to the mounting shaft 11 by a threaded connection, so as to ensure that the bearing structure 3 is always in a compressed state, and the entire guide roller 102 has a stable and reliable structure.

[0070] To prevent grease leakage from the lubrication chamber 12, the mounting structure 1 further includes a first sealing ring 141 for sealing between the mounting shaft 11 and the cover 13, a second sealing ring 142 for sealing between the bearing structure 3 and the cover 13, and a floating plug 15 disposed between the bearing structure 3 and the cover 13, thereby improving the sealing performance of the lubrication chamber 12. Furthermore, the provision of the floating plug 15 reduces the sealing resistance of the lubrication chamber 12, enabling easy rotation of the outer cylinder structure 2 and, consequently, reducing the starting torque of the guide roller 102. During drill bit rotation, the guide roller 102 is in both a revolving and self-rotating state, thereby reducing the loss of drill bit torque due to friction and resistance between the guide roller 102 and the wellbore wall.

[0071] The mounting structure 1 is further provided with a compensation chamber 16 connected to the lubrication chamber 12. One end of the compensation chamber 16 along the axial direction of the mounting structure 1 is connected to the external environment, and the other end of the compensation chamber 16 is connected to the lubrication chamber 12. When there is a lot of grease in the lubrication chamber 12, the excess grease enters the compensation chamber 16. When more grease is needed in the lubrication chamber 12, the grease flows from the compensation chamber 16 into the lubrication chamber 12 to lubricate the bearing structure 3.

[0072] like Figure 6 As shown, the mounting structure 1 also includes a plug 17 for sealing the compensation cavity 16, and an elastic ring 171 which is sleeved on the outside of the plug 17 and interference fits with the inner wall of the compensation cavity 16. The setting of the elastic ring 171 can be used to seal the compensation cavity 16 on the one hand, and on the other hand, the elastic ring 171 is sleeved on the outside of the plug 17 to stop the plug 17 and ensure that the plug 17 will not fall off from the compensation cavity 16 during construction vibration.

[0073] To secure and position the elastic ring 171, a receiving groove for accommodating the elastic ring 171 is provided on the outer wall of the plug 17 and / or the inner wall of the compensation cavity 16. The elastic ring 171 protrudes from the receiving groove, facilitating an interference fit between the elastic ring 171 and the inner wall of the compensation cavity 16 or the outer wall of the plug 17. In this embodiment, the receiving groove is provided on the inner wall of the compensation cavity 16.

[0074] Furthermore, the outer cylinder structure 2 is sleeved on the outside of the mounting shaft 11 and abuts against the cover 13 , that is, the outer cylinder structure 2 rotates relative to the mounting structure 1 along the circumferential direction of the mounting structure 1 under the action of external force.

[0075] In the embodiment, the end of the outer cylinder structure 2 in the axial direction abuts against the cover 13, increasing the contact area of the outer cylinder structure 2 and the mounting structure 1, and improving the stability of the outer cylinder structure 2 during rotation.

[0076] In the embodiment, the outer side of the outer cylinder structure 2 abuts against the well wall. When the guide roller 102 rotates relative to the guide device 10, the outer cylinder structure 2 is subjected to the friction force of the well wall, thereby driving the outer cylinder structure 2 to rotate relative to the mounting structure 1, that is, the guide roller 102 rotates along its axial direction.

[0077] The outer side of the outer cylinder structure 2 is provided with a plurality of inserts 21. When the outer cylinder structure 2 abuts against the well wall, the inserts 21 increase the friction force between the outer cylinder structure 2 and the well wall, thereby driving the outer cylinder structure 2 to rotate.

[0078] In the embodiment, the outer side of the outer cylinder structure 2 is provided with a protective film with a thickness of not less than 2 mm. The protective film is made by nitriding process. The protective film can effectively prolong the service life of the guide roller.

[0079] The bearing structure 3 is arranged in the lubricating cavity 12. The grease in the lubricating cavity 12 lubricates the rotation of the bearing structure 3, thereby reducing the torque of the rotation of the outer cylinder structure 2. The outer cylinder structure 2 and the mounting structure 1 are rotationally connected through the bearing structure 3. Specifically, the inner ring of the bearing structure 3 abuts against the mounting shaft 11, and the outer ring of the bearing structure 3 abuts against the inner side of the outer cylinder structure 2, thereby assisting the rotation of the outer cylinder structure 2 relative to the mounting structure 1.

[0080] The guide roller 102 of the present application comprises a plurality of bearing structures 3 arranged along the circumference of the central shaft 11. The bearing structure 3 comprises a bearing arranged in the lubricating cavity 12. The inner ring of the bearing abuts against the mounting shaft 11, and the outer ring of the bearing abuts against the inner side of the outer cylinder structure 2.

[0081] In the embodiment, the mounting structure 1 further comprises a retaining ring 18 arranged on the outer side of the mounting shaft 11 to fix the bearing. The retaining ring 18 comprises a fixing ring 181 and an adjusting ring 182 abutting against the inner ring of the bearing, respectively. The axial length of the fixing ring 181 along the mounting shaft 11 is greater than the length of the adjusting ring 182. The radial thickness of the fixing ring 181 along the mounting shaft 11 is greater than the thickness of the adjusting ring 182. The fixing ring 181 is more easily matched with the mounting shaft 11. The adjusting ring 182 is used to adjust the angle of the bearing structure 3, thereby avoiding stress concentration and over-constraint, making the structure bear force more reasonably, and reducing the processing difficulty and cost of the retaining ring 18.

[0082] The bearing includes a first bearing 31 and a second bearing 32 arranged symmetrically with respect to the center of the mounting structure 1 at both ends of the lubricating cavity 12, so that the bearing can be reversely stressed, ensuring that the guide roller 102 can bear very large axial load, and the center of gravity of the guide roller 102 is located at the center position, improving the stability of the guide roller 102 during rotation.

[0083] The bearing in the application adopts a double-thrust bearing structure, which can avoid damage of the guide roller 102 caused by external force of the well wall and falling rock blocks during drilling and tripping.

[0084] As shown in Figure 6 The pressure balance structure 4 includes a piston 41 in sealing sliding fit with the compensation cavity 16, an elastic member 42 connected to the piston 41 away from the lubricating cavity 12, and the other end of the elastic member 42 connected or abutted with the plug 17. The elastic member 42 in compression state exerts pressure on the bottom wall of the compensation cavity 16 away from the lubricating cavity 12, so as to realize the purpose that the internal pressure of the compensation cavity 16 is greater than the external pressure. In addition, the elastic member 42 indirectly exerts pressure on the grease through the piston 41, so that the lubricating cavity 12 is filled with grease, which is beneficial to lubrication of the bearing structure 3. At the same time, the floating plug 15 at the other end of the lubricating cavity 12 is extruded, improving the sealing performance of the lubricating cavity 12. When the elastic member 42 gradually changes from the compression state to the natural state, the elastic member 42 pushes the piston 41, and then pushes the grease in the compensation cavity 16 into the lubricating cavity 12.

[0085] In the embodiment, a sealing ring 43 is arranged between the piston 41 and the compensation cavity 16, improving the sealing performance of the compensation cavity 16.

[0086] The pressure balance structure 4 can replace elastic members 42 of different specifications according to the depth of construction, and generally one specification is suitable for 200 meters.

[0087] In the embodiment, the guide device 10 further includes a reinforcing rib 105 arranged outside the guide body 101, and the mounting seat 104 is fixed on the reinforcing rib 105.

[0088] As shown in Figure 3As shown, the guide device 10 further comprises a residue discharging channel 106 axially penetrating the guide body 101, and a high-pressure gas cavity 107 arranged outside the residue discharging channel 106, the distance between the residue discharging channel 106 and the high-pressure gas cavity 107 is not greater than the diameter of the high-pressure gas cavity 107, and the gas is delivered from the high-pressure gas cavity 107 to the below of the guide body 101 to mix with the slurry to form a gas-liquid mixture, and the gas-liquid mixture carries the residue generated during drilling to discharge from the residue discharging channel 106. In the present application, the high-pressure gas cavity 107 is designed to be close to the residue discharging channel 106, which is beneficial to indirectly carrying the residue out of the well by high-pressure gas.

[0089] The guide device 10 further comprises a receiving cavity outside the high-pressure gas cavity 107, a counterweight ring 108 arranged in the receiving cavity, and a cover plate 109 used for covering the receiving cavity, the design of the counterweight ring 108 can increase the weight of the guide device 10, which can greatly increase the self-weight of the guide device 10, thereby reducing the overall height of the drill bit.

[0090] In the present embodiment, the radial dimension of the counterweight ring 108 is greater than the diameter of the residue discharging channel 106, which increases the weight of the guide device 10, and further improves the stability of the guide device 10.

[0091] As shown in the drawings, Figure 4 The cover plate 109 is inserted and matched with the guide body 101, the end of the guide body 101 is provided with an insertion slot for accommodating the cover plate 109, which facilitates the disassembly of the cover plate 109, that is, the counterweight ring 108 can be disassembled, and the construction personnel can replace the counterweight ring 108 with different weights according to different construction objects, thereby improving the adaptability of the guide device 10.

[0092] In order to prevent the cover plate 109 from falling off the guide body 101 during construction, the guide device 10 further comprises a clamping block 1091 clamped on the cover plate 109 and the guide body 101 to fixedly install the cover plate 109 on the guide body 101.

[0093] In the present embodiment, the thickness of the cover plate 109 is not greater than the thickness of the mounting portion 103, that is, the axial dimension of the mounting portion 103 is greater than the thickness of the cover plate 109, which improves the structural strength of the guide device 10.

[0094] As shown in the drawings, Figure 8As shown, the fixing member 40 is in interference fit with the flanges of the guide device 10 and the connecting device 30, the fixing member 40 is a wing-shaped profiled card, the fixing member 40 includes a pair of wing plates 41, a web plate 42 fixedly connected between the wing plates 41, a plurality of matched bolt holes are symmetrically arranged on the wing plates 41, the forward bolt and the reverse bolt are respectively matched with the bolt holes, that is, the guide device 10 and the connecting device 30 are fixed together, so as to ensure that there is no loosening during rotation, to bear dynamic torque, resist dynamic torque generated by the rotation of the drill bit, and improve the stability of the drill bit.

[0095] As shown in the drawings, Figure 9 As shown, the end of the transition module 50 is provided with an internal hexagonal socket joint 51 for docking the drill rod, the slag discharge channel 106 extends to the upper end of the transition module 50, and the transition module 50 is conical. Due to the large change in the cross-sectional area of the transition module 50, cracks and fractures are easily generated under alternating loads. Compared with the conventional method of casting the transition module by pouring cast steel, the present application adopts 35CrMo material to forge and machine the transition module 50, thereby improving the strength of the transition module 50.

[0096] The present application also provides a vertical shaft drilling machine, which comprises the drill bit for hard rock strata described above, improves the stability during construction and improves the service life of the drill bit.

[0097] In summary, the drill bit for hard rock strata of the present application improves the stability during construction, rock breaking efficiency and service life of the cutter head in the special environment of hard rock strata through the design of the cutter head assembly.

[0098] It should be understood that although the present specification is described in terms of embodiments, each embodiment does not contain only one independent technical solution, and the description manner of the specification is only for the sake of clarity, and those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0099] The series of detailed descriptions listed above are only specific descriptions of feasible embodiments of the present application, and are not used to limit the protection scope of the present application, and any equivalent embodiments or changes made without departing from the spirit of the present application should be included in the protection scope of the present application.

Claims

1. A drill bit for hard rock formations, comprising a cutterhead assembly, wherein the cutterhead assembly comprises a base plate and a cutter mounted on the base plate, wherein: The tools include a pair of center hobs, a pair of inner ring cutters located outside the center hobs, and several outer ring cutters. The center hobs are close to the center of the base plate and are symmetrically arranged on both sides of the center. The base plate includes a base plate body for installing the outer ring cutters, and mounting grooves provided on the base plate body for installing the center hobs and inner ring cutters. The center hobs, inner ring cutters and several outer ring cutters are respectively located on different radial directions of the base plate, and the horizontal sections of the trajectory lines of all tools are in the same plane.

2. The drill bit for hard rock formations according to claim 1, wherein: A pair of central hobs are arranged at intervals in the transverse direction, and a pair of inner ring cutters are respectively located on the outer sides of the pair of central hobs in the longitudinal direction. The inner ring cutters are arranged in a centrally symmetrical manner with respect to the center of the base plate.

3. The drill bit for hard rock formations according to claim 1, wherein: The outer ring tool includes a pair of first tools adjacent to the center hob and a pair of second tools located outside the inner ring tool. In the radial direction of the base plate, the radius of the circle where the first tool is located is smaller than the radius of the circle where the second tool is located. The cutting edges of the first tool and the second tool are inclined inward and downward, and the included angle is 10°-20°.

4. The drill bit for hard rock formations according to claim 3, wherein: The outer ring tool also includes a pair of third tools and a fourth tool located at the edge of the base plate. The third tool and the fourth tool are arranged at intervals along the circumference of the base plate. In the radial direction of the base plate, the cutting edges of the third tool and the fourth tool are inclined outward and upward, and the included angle is 30°-40°.

5. The drill bit for hard rock formation according to claim 1, wherein: The base plate, the cutter and the cutter mounting base form a cutter disc, and the center of gravity of the cutter disc is horizontally projected at the center of the base plate.

6. The drill bit for hard rock formation according to any one of claims 1 to 5, characterized in that: The cutterhead assembly also includes a fixing device fixedly connected to the side of the base plate away from the tool, the drill bit includes a slag discharge channel penetrating in the up and down directions, and a high-pressure air cavity outside the slag discharge channel, the slag discharge channel includes a slag discharge curve inclined outward and penetrating the fixing device, and the cutterhead assembly also includes a counterweight cavity spaced apart from the slag discharge curve.

7. The drill bit for hard rock formation according to claim 6, wherein: The cutter head assembly further includes a stopper provided at the end of the slag discharge channel.

8. The drill bit for hard rock formations according to claim 6, wherein: The cutter disc assembly also includes a plurality of slurry return ports provided on the bottom plate and connected to the slag discharge channel. The slurry return ports are provided at intervals along the circumference of the bottom plate at the edge of the bottom plate. The cutter disc assembly also includes a ring plate provided outside the slurry return ports.

9. The drill bit for hard rock formation according to claim 6, wherein: The drill bit also includes at least one set of guide modules fixedly connected to the side of the cutter disc assembly away from the tool, the guide module includes a guide device fixedly connected to the cutter disc assembly, a connecting device fixedly installed on the side of the guide device away from the cutter disc assembly, a fixing part for fixing the guide device and the connecting device, and a plurality of connecting bolts, the connecting bolts including forward bolts and reverse bolts, and the forward bolts and reverse bolts are symmetrically arranged.

10. The drill bit for hard rock formation according to claim 9, wherein: The slag discharge channel further comprises a lower slag discharge pipe located in a guide device adjacent to the fixing device, the lower slag discharge pipe is communicated with the slag discharge bend, and a plurality of mixed gas holes are formed in the lower slag discharge pipe.

11. The drill bit for hard rock formation according to claim 9, wherein: The fixing member is interference-fitted with the guide device and the flange of the connecting device.

12. The drill bit for hard rock formation according to claim 9, wherein: The guide device includes a guide body and at least two guide rollers installed on the side of the guide body; the guide rollers are arranged in a centrally symmetrical manner with respect to the guide body, and the distance between the guide rollers and the guide module is smaller than the radial dimension of the guide rollers.

13. The drill bit for hard rock formation according to claim 12, wherein: The guide roller includes a mounting structure having a connected lubrication chamber and a grease compensation chamber, an outer cylinder structure, at least one bearing structure installed in the lubrication chamber and used to rotatably connect the mounting structure and the outer cylinder structure, and a pressure balancing structure provided in the compensation chamber to apply pressure to the bottom wall of the compensation chamber away from the lubrication chamber, so that the internal pressure of the compensation chamber is not less than the external pressure.

14. The drill bit for hard rock formation according to claim 9, wherein: The drill bit further includes a transition module for fixedly connecting the guide module and the drill rod, and the slag discharge channel extends to the upper end of the transition module.

15. A vertical shaft drilling rig, characterized in that: The drill bit for hard rock formations comprises the drill bit for hard rock formations according to any one of claims 1 to 9.

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