Dual-power impact composite drill bit and method

Abstract

The dual-power impact composite drill bit comprises a first-stage drill bit and a second-stage drill bit arranged on the first-stage drill bit in a sleeving mode, and a first thrust cylindrical roller bearing, a rotor, a second thrust cylindrical roller bearing, an anvil, an impact hammer, a spring, a third thrust cylindrical roller bearing and a lower connector are sequentially arranged on a transmission shaft of the first-stage drill bit in a sleeving mode; the first thrust cylindrical roller bearing is arranged between the first-stage drill bit and the second-stage drill bit; a fourth thrust cylindrical roller bearing is arranged between the rotor and the first-stage drill bit; the front part of the rotor is screwed with an outer ring gear and is meshed with an inner ring gear screwed in the secondary drill bit; the second thrust cylindrical roller bearing is arranged between the rotor and the anvil, and the anvil is in threaded connection with the second-stage drill bit pipe body; the third thrust cylindrical roller bearing is arranged between the second-stage drill bit and the lower connector, and the lower connector is in threaded connection with the rear portion of the first-stage drill bit. The double-power rock breaking drill bit is composed of two stages of drill bits, the power of the first-stage drill bit is from a drilling machine or a hole bottom screw drill, the power of the second-stage drill bit is from a built-in rotor, double-power rock breaking drilling is achieved, and the drilling efficiency can be improved.

Description

Technical Field

[0001] The invention belongs to the technical field of drill bits and relates to a dual-power impact composite drill bit and a method. Background Art

[0002] In the process of tunnel drilling, it is crucial to complete the drilling operation efficiently. In order to achieve efficient drilling, appropriate drilling process methods and supporting equipment are required. At present, rotary cutting drilling is generally used for soft and medium-hard formations. This method mostly uses PDC drill bits for rock crushing drilling. In hard formations, the crushing efficiency is low due to the small depth of conventional PDC teeth into the hard formation. Impact rotary drilling is a drilling method that applies impact force to the formation through an additional impact generating device to achieve volume crushing of the hard formation. This method mostly uses carbide ball tooth drill bits, which can effectively improve the drilling efficiency of hard formations. However, the drill tool combination for impact rotary drilling is generally a ball tooth drill bit with a hydraulic or pneumatic impactor. The single ball tooth drill bit does not have an impact function. In addition, the existing PDC drill bits and ball tooth drill bits are single-stage full rock crushing drill bits. There are currently no patents, papers or reports on double-stage full rock crushing drill bits. And whether it is conventional drilling construction or directional drilling construction, the rock crushing power of the relevant drill bit mainly relies on equipment such as tunnel drilling rigs, bottom hole screw drills, hydraulic impactors, etc., and the single drill bit does not yet have an autonomous power function. Summary of the invention

[0003] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a dual-power impact composite drill bit and method to solve the problems that the prior art lacks a two-stage comprehensive rock crushing drill bit technology and a single drill bit does not yet have an autonomous power function.

[0004] In order to solve the above technical problems, the present invention adopts the following technical solutions to achieve the above problems:

[0005] A dual-power impact composite drill bit comprises a primary drill bit and a secondary drill bit, wherein the secondary drill bit is sleeved outside the primary drill bit;

[0006] The first-stage drill bit includes an integrated coaxial front end head and a transmission shaft; the second-stage drill bit includes an integrated coaxial tubular end head and a tubular body;

[0007] The transmission shaft is sleeved with a first thrust cylindrical roller bearing, a rotor, a second thrust cylindrical roller bearing, an anvil, a hammer, a spring, a third thrust cylindrical roller bearing, and a lower joint in sequence from front to back;

[0008] The first thrust cylindrical roller bearing is placed between the rear end face of the front end head of the first drill bit and the first annular platform at the front part of the secondary drill bit tube body; the fourth thrust cylindrical roller bearing is provided between the front end of the rotor and the rear end face of the front end head of the first drill bit; the front part of the rotor is sleeved with a screw-connected outer ring gear and the inner ring gear screw-connected with the inner wall of the front part of the secondary drill bit tube body is meshed with each other; the second thrust cylindrical roller bearing is placed between the rear end of the rotor and the anvil, and the anvil is screwed to the inner wall of the secondary drill bit tube body; the third thrust cylindrical roller bearing is provided between the second annular platform at the rear part of the secondary drill bit and the lower joint, and the lower joint is screwed to the rear part of the transmission shaft of the first drill bit.

[0009] The present invention also includes the following technical features:

[0010] Specifically, the front end face of the front end head of the first-stage drill bit is provided with multiple groups of first PDC teeth and multiple groups of first ball teeth; the first PDC teeth and the first ball teeth are arranged alternately; the front end head is provided with multiple first water holes evenly distributed around the circumference, and the first water holes communicate the front end face and the rear end face of the front end head.

[0011] Specifically, the front end face of the tubular end of the secondary drill bit is provided with multiple groups of second PDC teeth and multiple groups of second ball teeth; the second PDC teeth and the second ball teeth are arranged alternately; the tubular end is provided with multiple second water holes evenly distributed around the circumference, and the inner wall of the front part of the tube body is provided with multiple third water holes evenly distributed around the circumference, and the second water holes are connected with the third water holes in a one-to-one correspondence; the inner channel of the tube body of the secondary drill bit is the first center through hole, and the second water holes and the third water holes communicate the front end face of the secondary drill bit with the first center through hole.

[0012] Specifically, the rotor is a hollow structure as a whole, the central channel is a second central through hole, and the transmission shaft passes through the second central through hole; the front outer wall of the rotor is provided with a male thread section for connecting the outer ring gear, the rear is provided with an annular boss and the rear end face is in contact with the second thrust cylindrical roller bearing; the middle outer wall of the rotor is provided with a plurality of groups of axially evenly distributed spiral blades, the spiral blades communicate the front and rear end faces of the rotor, with the front end face as the reference plane, the spiral angle of the spiral blades is 30° counterclockwise, and the high-pressure liquid flow drives the rotor to rotate after passing through the spiral blades.

[0013] Specifically, the anvil is an annular structure as a whole and the central through hole is the third central through hole, the inner diameter of the third central through hole is slightly larger than the outer diameter of the transmission shaft of the first-stage drill bit; the outer wall of the anvil is provided with a male thread for threaded connection with the second-stage drill bit; the rear end face of the anvil is provided with a plurality of circumferentially evenly distributed ascending inclined surfaces, and a flow groove is provided between the two ascending inclined surfaces.

[0014] Specifically, the hammer is an annular structure as a whole and its outer diameter is smaller than the outer diameter of the anvil, so that the liquid flows into the flow groove through the annulus between the hammer and the tube body; the rear end of the hammer is provided with an annular boss as a spring seat, and one end of the spring is placed in the annular boss; the through hole in the middle of the hammer is the fourth center through hole, and the inner diameter of the fourth center through hole is slightly larger than the outer diameter of the transmission shaft of the first-stage drill bit, ensuring the reciprocating motion of the hammer along the transmission shaft; the front end of the hammer is provided with a plurality of circumferentially evenly distributed impact teeth, and the height of the impact teeth is consistent with the lifting height of the rising inclined surface; the other end of the spring is placed on the end face of the lower joint.

[0015] Specifically, a transmission shaft joint is provided at the front end of the lower joint, and a female thread is provided inside the transmission shaft joint for connecting the male thread at the rear end of the transmission shaft. A plurality of circumferentially evenly distributed fan-shaped flow channels are provided in the middle part of the lower joint. The rear end of the lower joint is a drill tool joint, and a female thread is provided on its inner ring for connecting the subsequent drill rod. The fan-shaped flow channel communicates the drill rod flow channel and the pipe body.

[0016] Specifically, after the anvil and the secondary drill bit are tightened, the fourth thrust cylindrical roller bearing, the rotor, and the second thrust cylindrical roller bearing are axially limited and fixed on the transmission shaft of the primary drill bit; after the lower joint and the transmission shaft are tightened, the primary drill bit, the first thrust cylindrical roller bearing, the third thrust cylindrical roller bearing and the secondary drill bit are axially limited and fixed; when the entire set of drill bits is installed, the impact tooth of the hammer contacts the end face of the anvil, and the spring is in a compressed state at this time, so that the hammer is pressed against the anvil.

[0017] A two-stage drilling method for a dual-power impact composite drill bit, the method is based on the dual-power impact composite drill bit; comprising:

[0018] The dual-power composite drill bit is connected to the drill pipe and the water feeder through the lower joint and passed through the power head of the tunnel drilling rig. The water feeder is connected to the mud pump truck. When the construction starts, the mud pump truck is turned on, and the high-pressure flushing liquid flows into the lower joint through the water feeder and the drill pipe. The liquid flows into the upper cavity of the rotor through the fan-shaped flow passage of the lower joint, the outer annulus of the hammer, and the flow groove of the anvil, driving the rotor to rotate forward. The rotation of the rotor causes the outer ring gear to rotate, and the outer ring gear is meshed with the inner ring gear connected to the secondary drill bit, so that the secondary drill bit rotates;

[0019] The lower joint is mechanically connected to the drill pipe so that the rotation speed of the lower joint is consistent with that of the drilling rig. The lower joint is mechanically connected to the transmission shaft of the first-stage drill bit so that the first-stage drill bit rotates at the rotation speed of the drilling rig.

[0020] The first-stage drill bit and the second-stage drill bit mainly use the end face PDC teeth to perform rotary cutting and rock crushing.

[0021] An axial impact method for a dual-power impact composite drill bit, the method is based on the dual-power impact composite drill bit; comprising:

[0022] The rotation of the secondary drill bit drives the anvil to rotate. The positive rotation of the anvil causes the impact teeth of the hammer to rise along the ascending slope of the anvil. At this time, the spring is further compressed to store energy. After the hammer is lifted to the highest point of the anvil, it instantly falls back and rushes to the anvil, impacting once. Since the hammer is sleeved on the transmission shaft of the primary drill bit and has the same rotation speed as the drilling rig, the secondary drill bit rotates 2 circles and the primary drill bit rotates 1 circle, then the secondary drill bit rotates 1 circle relative to the primary drill bit, and the hammer impacts the anvil. The primary and secondary drill bits mainly use the end face ball teeth to impact and rotate to crush rocks;

[0023] Under the conditions of certain pump pressure and pump volume, the rotor rotation speed is constant. By adjusting the rotation speed of the drill rig, the impact frequency can be controlled. By increasing the rotation speed of the drill rig, the impact frequency is reduced, which is suitable for soft and medium-hard formations. By reducing the rotation speed of the drill rig, the impact frequency is increased, which is suitable for drilling construction in hard formations.

[0024] Compared with the prior art, the present invention has the following technical effects:

[0025] The drill bit of the present invention is composed of a two-stage drill bit, wherein the power of the first-stage drill bit comes from a drilling rig or a bottom-hole screw drill, and the power of the second-stage drill bit comes from a built-in rotor turbine, thereby realizing dual-power rock-breaking drilling and being beneficial to improving drilling efficiency.

[0026] The drill bit of the present invention has a built-in impact mechanism, which can add axial impact force while achieving conventional rotary drilling, and is matched with PDC teeth and ball teeth compositely arranged on the end faces of the first-stage drill bit and the second-stage drill bit, so it can be used in soft, medium, hard formations and alternating formations.

[0027] The drill bit of the present invention makes full use of the power of the drilling rig, the power of the screw and the pressure of the flushing fluid, realizes the effective utilization of energy during the construction process, has a simple rotor structure, and the gear transmission mechanism has direct transmission. The impact mechanism adopts a spring energy storage structure with few wearing parts, and the impact work can be changed by replacing the energy storage spring.

[0028] The impact frequency of the present invention is determined by the difference between the drilling rig rotation speed or the screw drive shaft rotation speed and the rotation speed of the rotor driving the secondary drill bit. The rotor rotation speed is determined by the pump pressure and flow rate of the mud pump truck. Under the conditions of certain pump pressure and pump volume, the impact frequency can be increased or decreased by adjusting the drilling rig rotation speed or the screw drive shaft rotation speed. The process is simple to operate and has rapid feedback. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 1 is an overall schematic diagram of the dual-power impact composite drill bit of the present invention.

[0030] Figure 2 Schematic diagram II of the dual-power impact composite drill bit of the present invention.

[0031] Figure 3It is a front view of a first-stage drill bit of the dual-power impact composite drill bit of the present invention.

[0032] Figure 4 It is a cross-sectional view of the first-stage drill bit AA of the dual-power impact composite drill bit of the present invention.

[0033] Figure 5 It is a front view of the secondary drill bit of the dual-power impact composite drill bit of the present invention.

[0034] Figure 6 It is a cross-sectional view of the secondary drill bit BB of the dual-power impact composite drill bit of the present invention.

[0035] Figure 7 It is a schematic diagram of the rotor blades of the dual-power impact composite drill bit of the present invention.

[0036] Figure 8 It is a schematic diagram of the anvil of the dual-power impact composite drill bit of the present invention.

[0037] Fig. 9 It is a schematic diagram of the hammer of the dual-power impact composite drill bit of the present invention.

[0038] Fig.10 It is a front view of the lower joint of the dual-power impact composite drill bit of the present invention.

[0039] Fig.11 It is a cross-sectional view of the lower joint CC of the dual-power impact composite drill bit of the present invention.

[0040] The meaning of each number in the figure is:

[0041] 1. primary drill bit, 2. secondary drill bit, 3. first thrust cylindrical roller bearing, 4. inner ring gear, 5. rotor, 6. second thrust cylindrical roller bearing, 7. anvil, 8. hammer, 9. spring, 10. third thrust cylindrical roller bearing, 11. lower joint, 12. fourth thrust cylindrical roller bearing, 13. outer ring gear;

[0042] 101. first PDC tooth, 102. first ball tooth, 103. first water eye, 104. transmission shaft;

[0043] 201. second PDC tooth, 202. second ball tooth, 203. second water hole, 204. first annular platform, 205. first central through hole, 206. third water hole, 207. second annular platform;

[0044] 501. male thread segment, 502. spiral blade, 503. annular boss, 504. second central through hole;

[0045] 701. rising slope, 702. flow channel, 703. third central through hole;

[0046] 801. impact tooth, 802. spring seat, 803. fourth center through hole;

[0047] 1101. Fan-shaped flow channel, 1102. Transmission shaft joint, 1103. Drill tool joint. DETAILED DESCRIPTION

[0048] Specific embodiments of the present invention are given below. It should be noted that the present invention is not limited to the following specific embodiments, and all equivalent changes made on the basis of the technical solution of this application fall within the protection scope of the present invention.

[0049] Embodiment 1:

[0050] like Figures 1 to 11 As shown, this embodiment provides a dual-power impact composite drill bit, including a primary drill bit 1 and a secondary drill bit 2, wherein the secondary drill bit 2 is sleeved outside the primary drill bit 1; the primary drill bit 1 includes an integrated coaxial front end head and a transmission shaft 104; the secondary drill bit 2 includes an integrated coaxial tubular end head and a tubular body.

[0051] The transmission shaft 104 is sleeved with a first thrust cylindrical roller bearing 3, a rotor 5, a second thrust cylindrical roller bearing 6, an anvil 7, a hammer 8, a spring 9, a third thrust cylindrical roller bearing 10, and a lower joint 11 in sequence from front to back.

[0052] The first thrust cylindrical roller bearing 3 is placed between the rear end face of the front end of the primary drill bit 1 and the first annular platform 204 at the front end of the secondary drill bit 2; the fourth thrust cylindrical roller bearing 12 is arranged between the front end of the rotor 5 and the rear end face of the front end of the primary drill bit 1, and the rotor 5 can rotate freely around the primary drill bit 1; the front end of the rotor 5 is sleeved with a screw-connected outer ring gear 13 and meshes with the inner ring gear 4 screw-connected to the inner wall of the front end of the secondary drill bit 2, and the two have the same number of teeth; the second thrust cylindrical roller bearing 6 is placed between the rear end of the rotor 5 and the anvil 7, and the anvil 7 is screwed to the inner wall of the secondary drill bit 2; the third thrust cylindrical roller bearing 10 is arranged between the second annular platform 207 at the rear end of the secondary drill bit 2 and the lower joint 11, and the lower joint 11 is screwed to the rear end of the transmission shaft 104 of the primary drill bit 1. The diameter of the front end is larger than the diameter of the transmission shaft 104, and there is an annulus between the transmission shaft 104 and the tube body.

[0053] The front end face of the front end head of the first-stage drill bit 1 is provided with multiple groups of first PDC teeth 101 and multiple groups of first ball teeth 102; the first PDC teeth 101 and the first ball teeth 102 are arranged alternately; a plurality of axial first water holes 103 evenly distributed in six circles are provided in the front end head, and the first water holes 103 communicate the front end face and the rear end face of the front end head for cooling the first PDC teeth 101 and the first ball teeth 102.

[0054] The front end face of the tubular end of the secondary drill bit 2 is provided with multiple groups of second PDC teeth 201 and multiple groups of second ball teeth 202; the second PDC teeth 201 and the second ball teeth 202 are arranged alternately; a plurality of axial second water holes 203 evenly distributed such as 6 circles are provided in the tubular end, and a plurality of first center through holes 206 evenly distributed such as 6 circles are provided on the inner wall of the front part of the tube body, and the second water holes 203 are connected with the first center through holes 206 in a one-to-one correspondence; the inner channel of the tube body of the secondary drill bit 2 is the first center through hole 205, and the second water holes 203 and the first center through hole 206 communicate with the front end face of the secondary drill bit 2 and the first center through hole 205; specifically, a female thread is provided at the left end of the first center through hole 205 for connecting the inner ring gear 4, and a female thread is provided at the right end of the first center through hole 205 for connecting the anvil 7.

[0055] The rotor 5 is a hollow structure as a whole, and the central channel is a second central through hole 504, and the transmission shaft 104 passes through the second central through hole 504; the front outer wall of the rotor 5 is provided with a male thread section 501 for connecting the outer ring gear 13, and the rear is provided with an annular boss 503, and the rear end face is in contact with the second thrust cylindrical roller bearing 6; the middle outer wall of the rotor 5 is provided with multiple groups, such as 3 groups, of axially uniformly distributed spiral blades 502, and the spiral blades 502 communicate with the front and rear end faces of the rotor 5, with the front end face as the reference plane, and the spiral angle of the spiral blades 502 is 30° counterclockwise, and the high-pressure liquid flow drives the rotor 5 to rotate clockwise after passing through the spiral blades 502.

[0056] The anvil 7 is an annular structure as a whole and the central through hole is the third central through hole 703, the inner diameter of the third central through hole 703 is slightly larger than the outer diameter of the transmission shaft 104 of the first-stage drill bit 1; the outer wall of the anvil 7 is provided with a male thread for threaded connection with the second-stage drill bit 2; the rear end face of the anvil 7 is provided with a plurality of rising inclined surfaces 701 evenly distributed on four circumferences, and a flow groove 702 is provided between two rising inclined surfaces 701.

[0057] The hammer 8 is an annular structure as a whole and its outer diameter is smaller than the outer diameter of the anvil 7, so that the liquid flows into the flow groove 702 through the annulus between the hammer 8 and the tube body; an annular boss is provided at the rear end of the hammer 8 as a spring seat 802, and one end of the spring 9 is placed in the annular boss; the through hole in the middle of the hammer 8 is the fourth center through hole 803, and the inner diameter of the fourth center through hole 803 is slightly larger than the outer diameter of the transmission shaft 104 of the first-stage drill bit 1, ensuring that the hammer 8 reciprocates along the transmission shaft 104; a plurality of impact teeth 801 evenly distributed such as 4 circles are provided at the front end of the hammer 8, and the height of the impact teeth 801 is consistent with the lifting height of the rising slope 701; the other end of the spring 9 is placed on the end face of the lower joint.

[0058] A transmission shaft joint 1102 is provided at the front end of the lower joint, and a female thread is provided inside the transmission shaft joint 1102 for connecting to the male thread at the rear end of the transmission shaft 104. A plurality of fan-shaped flow channels 1101 evenly distributed in five circles are provided in the middle of the lower joint. The rear end of the lower joint is a drill tool joint 1103, and a female thread is provided on its inner ring for connecting to subsequent drill rods. The fan-shaped flow channel 1101 communicates the drill rod flow channel with the first central through hole 205 of the pipe body.

[0059] After the anvil 7 and the secondary drill bit 2 are tightened, the fourth thrust cylindrical roller bearing 12, the rotor 5, and the second thrust cylindrical roller bearing 6 are axially limited and fixed on the transmission shaft 104 of the primary drill bit 1; after the lower joint and the transmission shaft 104 are tightened, the primary drill bit 1, the first thrust cylindrical roller bearing 3, the third thrust cylindrical roller bearing 10 and the secondary drill bit 2 are axially limited and fixed; when the whole set of drill bits is installed, the impact tooth 801 of the hammer 8 contacts the end face of the anvil 7, and at this time the spring 9 is in a certain compression state, so that the hammer 8 is pressed against the anvil 7.

[0060] Embodiment 2:

[0061] This embodiment provides a dual-stage drilling method for a dual-power impact composite drill bit, which is based on the dual-power impact composite drill bit of embodiment 1; comprising:

[0062] The dual-power composite drill bit is connected to the drill pipe, water feeder, etc. through the lower joint and passed through the tunnel drilling rig power head. The water feeder is connected to the mud pump truck. When the construction starts, the mud pump truck is turned on, and the high-pressure flushing liquid flows into the lower joint through the water feeder and the drill pipe. The liquid flows into the upper cavity of the rotor through the fan-shaped flow channel of the lower joint, the outer annulus of the hammer, and the flow groove of the anvil, driving the rotor to rotate forward. The pump pressure is 3MPa, the pump volume is 300L / min, and the rotor rotation speed is about 100r / min. The rotation of the rotor causes the outer ring gear to rotate, and the outer ring gear is meshed with the inner ring gear connected to the secondary drill bit to rotate the secondary drill bit;

[0063] The lower joint is mechanically connected to the drill pipe, so that the rotation speed of the lower joint and the drilling rig are consistent. The lower joint is mechanically connected to the transmission shaft of the first-stage drill bit, so that the first-stage drill bit rotates at the rotation speed of the drilling rig, and the rotation speed of the drilling rig is controlled to be about 50r / min;

[0064] The first-stage drill bit and the second-stage drill bit mainly use the end face PDC teeth to perform rotary cutting and rock crushing.

[0065] This embodiment also provides an axial impact method for a dual-power impact composite drill bit, which is based on the dual-power impact composite drill bit of embodiment 1; comprising:

[0066] The rotation of the secondary drill bit drives the anvil to rotate (100r / min). The positive rotation of the anvil causes the impact teeth of the hammer to rise along the ascending slope of the anvil. At this time, the spring is further compressed to store energy. After the hammer is lifted to the highest point of the anvil, it instantly falls back and rushes to the anvil, impacting once. Since the hammer is sleeved on the transmission shaft of the primary drill bit and has the same rotation speed as the drilling rig (50r / min), the secondary drill bit rotates 2 circles and the primary drill bit rotates 1 circle, then the secondary drill bit rotates 1 circle relative to the primary drill bit, and the hammer impacts the anvil 4 times, with 200 impacts per minute. The primary and secondary drill bits mainly use the end face ball teeth to impact and rotate to crush rocks;

[0067] Under the conditions of certain pump pressure and pump volume, the rotor rotation speed is constant. By adjusting the rotation speed of the drill rig, the impact frequency can be controlled. Properly increasing the rotation speed of the drill rig will reduce the impact frequency, which is suitable for soft and medium-hard formations. Properly reducing the rotation speed of the drill rig will increase the impact frequency, which is suitable for drilling construction in hard formations.

[0068] The preferred embodiments of the present invention are described in detail above in conjunction with the accompanying drawings. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0069] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0070] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A dual-power impact composite drill bit, characterized in that: It comprises a primary drill bit (1) and a secondary drill bit (2), wherein the secondary drill bit (2) is sleeved outside the primary drill bit (1); The first-stage drill bit (1) comprises an integrated coaxial front end head and a transmission shaft (104); the second-stage drill bit (2) comprises an integrated coaxial tubular end head and a tubular body; The transmission shaft (104) is sleeved with a first thrust cylindrical roller bearing (3), a rotor (5), a second thrust cylindrical roller bearing (6), an anvil (7), a hammer (8), a spring (9), a third thrust cylindrical roller bearing (10), and a lower joint (11) in sequence from front to back; The first thrust cylindrical roller bearing (3) is arranged between the rear end face of the front end head of the first drill bit (1) and the first annular platform (204) at the front end of the tube body of the second drill bit (2); a fourth thrust cylindrical roller bearing (12) is arranged between the front end of the rotor (5) and the rear end face of the front end head of the first drill bit (1); a screw-connected outer ring gear (13) is sleeved on the front end of the rotor (5) and meshes with an inner ring gear (4) screw-connected to the inner wall of the front end of the tube body of the second drill bit (2); the second thrust cylindrical roller bearing (6) is arranged between the rear end of the rotor (5) and the anvil (7), and the anvil (7) is screw-connected to the inner wall of the tube body of the second drill bit (2); the third thrust cylindrical roller bearing (10) is arranged between the second annular platform (207) at the rear end of the second drill bit (2) and the lower joint (11), and the lower joint (11) is screw-connected to the rear end of the transmission shaft (104) of the first drill bit (1).

2. The dual-power impact composite drill bit according to claim 1, characterized in that: The front end face of the front end head of the first-stage drill bit (1) is provided with a plurality of groups of first PDC teeth (101) and a plurality of groups of first ball teeth (102); the first PDC teeth (101) and the first ball teeth (102) are arranged alternately; the front end head is provided with a plurality of first water holes (103) evenly distributed around the circumference, and the first water holes (103) communicate with the front end face and the rear end face of the front end head.

3. The dual-power impact composite drill bit according to claim 1, characterized in that: The front end face of the tubular end head of the secondary drill bit (2) is provided with a plurality of groups of second PDC teeth (201) and a plurality of groups of second ball teeth (202); the second PDC teeth (201) and the second ball teeth (202) are arranged alternately; the tubular end head is provided with a plurality of second water holes (203) evenly distributed around the circumference, the inner wall of the front part of the tube body is provided with a plurality of first central through holes (206) evenly distributed around the circumference, the second water holes (203) are connected to the first central through holes (206) in a one-to-one correspondence; the inner channel of the tube body of the secondary drill bit (2) is the first central through hole (205), the second water holes (203) and the first central through hole (206) communicate the front end face of the secondary drill bit (2) and the first central through hole (205).

4. The dual-power impact composite drill bit according to claim 1, characterized in that: The rotor (5) is a hollow structure as a whole, the central channel is a second central through hole (504), and the transmission shaft (104) passes through the second central through hole (504); the front outer wall of the rotor (5) is provided with a male thread section (501) for connecting the outer ring gear (13), the rear is provided with an annular boss (503), and the rear end face is in contact with the second thrust cylindrical roller bearing (6); the middle outer wall of the rotor (5) is provided with a plurality of groups of axially evenly distributed spiral blades (502), the spiral blades (502) communicate with the front and rear end faces of the rotor (5), with the front end face as a reference plane, the spiral angle of the spiral blades (502) is 30 degrees counterclockwise, and the high-pressure liquid flow drives the rotor (5) to rotate after passing through the spiral blades (502).

5. The dual-power impact composite drill bit according to claim 1, characterized in that: The anvil (7) is an annular structure as a whole and the central through hole is a third central through hole (703), the inner diameter of the third central through hole (703) is slightly larger than the outer diameter of the transmission shaft (104) of the first-stage drill bit (1); the outer wall of the anvil (7) is provided with a male thread for threaded connection with the second-stage drill bit (2); the rear end surface of the anvil (7) is provided with a plurality of circumferentially evenly distributed ascending inclined surfaces (701), and a flow groove (702) is provided between two ascending inclined surfaces (701).

6. The dual-power impact composite drill bit according to claim 5, characterized in that: The hammer (8) is an annular structure as a whole and its outer diameter is smaller than the outer diameter of the anvil (7), so that the liquid flows into the flow groove (702) through the annular space between the hammer (8) and the tube body; the rear end of the hammer (8) is provided with an annular boss as a spring seat (802), and one end of the spring (9) is placed in the annular boss; the middle through hole of the hammer (8) is a fourth central through hole (803), and the inner diameter of the fourth central through hole (803) is slightly larger than the outer diameter of the transmission shaft (104) of the first-stage drill bit (1), so as to ensure that the hammer (8) reciprocates along the transmission shaft (104); the front end of the hammer (8) is provided with a plurality of impact teeth (801) evenly distributed around the circumference, and the height of the impact teeth (801) is consistent with the lifting height of the rising inclined surface (701); the other end of the spring (9) is placed on the end surface of the lower joint (11).

7. The dual-power impact composite drill bit according to claim 1, characterized in that: The front end of the lower joint (11) is provided with a transmission shaft joint (1102), and the transmission shaft joint (1102) is provided with a female thread for connecting to the male thread of the rear end of the transmission shaft (104). The middle part of the lower joint (11) is provided with a plurality of circumferentially evenly distributed fan-shaped flow passages (1101). The rear end of the lower joint (11) is a drill tool joint (1103) whose inner ring is provided with a female thread for connecting to a subsequent drill rod. The fan-shaped flow passage (1101) communicates the drill rod flow channel with the inside of the pipe body.

8. The dual-power impact composite drill bit according to claim 1, characterized in that: After the anvil (7) and the secondary drill bit (2) are tightened, the fourth thrust cylindrical roller bearing (12), the rotor (5), and the second thrust cylindrical roller bearing (6) are axially limited and fixed on the transmission shaft (104) of the primary drill bit (1); after the lower joint (11) and the transmission shaft (104) are tightened, the primary drill bit (1), the first thrust cylindrical roller bearing (3), the third thrust cylindrical roller bearing (10) and the secondary drill bit (2) are axially limited and fixed; when the entire set of drill bits is installed, the impact teeth (801) of the hammer (8) are in contact with the end face of the anvil (7), and at this time the spring (9) is in a compressed state, so that the hammer (8) is pressed against the anvil (7).

9. A dual-stage drilling method for a dual-power impact composite drill bit, characterized in that: The method is based on the dual-power impact composite drill bit according to any one of claims 2 to 8; comprising: The dual-power composite drill bit is connected to the drill pipe and the water feeder through the lower joint and passed through the power head of the tunnel drilling rig. The water feeder is connected to the mud pump truck. When the construction starts, the mud pump truck is turned on, and the high-pressure flushing liquid flows into the lower joint through the water feeder and the drill pipe. The liquid flows into the upper cavity of the rotor through the fan-shaped flow passage of the lower joint, the outer annulus of the hammer, and the flow groove of the anvil, driving the rotor to rotate forward. The rotation of the rotor causes the outer ring gear to rotate, and the outer ring gear is meshed with the inner ring gear connected to the secondary drill bit, so that the secondary drill bit rotates; The lower joint is mechanically connected to the drill pipe so that the rotation speed of the lower joint is consistent with that of the drilling rig. The lower joint is mechanically connected to the transmission shaft of the first-stage drill bit so that the first-stage drill bit rotates at the rotation speed of the drilling rig. The first-stage drill bit and the second-stage drill bit mainly use the end face PDC teeth to perform rotary cutting and rock crushing.

10. An axial impact method for a dual-power impact composite drill, characterized in that: The method is based on the dual-power impact composite drill bit according to any one of claims 2 to 8; comprising: The rotation of the secondary drill bit drives the anvil to rotate. The positive rotation of the anvil causes the impact teeth of the hammer to rise along the ascending slope of the anvil. At this time, the spring is further compressed to store energy. After the hammer is lifted to the highest point of the anvil, it instantly falls back and rushes to the anvil, impacting once. Since the hammer is sleeved on the transmission shaft of the primary drill bit and has the same rotation speed as the drilling rig, the secondary drill bit rotates 2 circles and the primary drill bit rotates 1 circle, then the secondary drill bit rotates 1 circle relative to the primary drill bit, and the hammer impacts the anvil. The primary drill bit and the secondary drill bit mainly use the end face ball teeth to impact and rotate to crush rocks; Under the conditions of certain pump pressure and pump volume, the rotor rotation speed is constant. By adjusting the rotation speed of the drill rig, the impact frequency can be controlled. By increasing the rotation speed of the drill rig, the impact frequency is reduced, which is suitable for soft and medium-hard formations. By reducing the rotation speed of the drill rig, the impact frequency is increased, which is suitable for drilling construction in hard formations.

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