Drilling tool and drilling method

Abstract

The invention relates to the technical field of drilling equipment, and provides a drilling tool and a drilling method.The drilling tool comprises a drill bit mechanism, in the process that a drilling rod drives a fixedly-connected sleeve to rotate, the fixedly-connected sleeve drives a lifting sleeve to rotate, the lifting sleeve drives a hollow sleeve to rotate, and the hollow sleeve drives an annular step to rotate; due to the fact that the positions of the spliced positioning barrel and the well drilling rod are kept unchanged in the vertical direction, the positions of the positioning shaft and the well drilling rod are kept unchanged in the vertical direction, and when the annular step rotates, under the cooperation of the annular step and the positioning shaft, the hollow sleeve can be driven to move up and down in a reciprocating mode, and the limiting barrel is driven to move up and down in a barrel cavity; according to the principle similar to a shield tunneling machine, the composite drill bit can conduct impact type crushing on a foundation in an up-down reciprocating mode, the strength of rock is firstly reduced in a punching mode, then the composite drill bit can conduct rotary scraping rock breaking while impacting in an up-down reciprocating mode, and the drilling efficiency is greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of drilling equipment, and in particular to a drilling tool and a drilling method. Background Art

[0002] Drilling is the work of drilling holes in the ground using mechanical equipment or manpower. It usually refers to the engineering of drilling wells and large-diameter water supply wells for the exploration or development of liquid and gaseous minerals such as oil and natural gas. Drilling is widely used in national economic construction. Rotary drilling is widely used in my country's oil (gas) fields. The main drilling equipment includes derricks, operating platforms, diesel engines, drilling rigs, drilling tools, mud pumps, generators and testing equipment, as well as fuel tanks, boilers, etc.

[0003] With the continuous depletion of shallow oil and gas resources in China, oil and gas exploration and development have begun to shift to deep oil and gas resources. As the depth of the formation increases, the hardness of the rock in the formation and the difficulty of drilling and breaking the rock continue to increase. Therefore, it is necessary to use drilling tools to break the rocks in the deep formation. In the related technology, after searching, the existing patent (Announcement No.: CN105672884B) discloses a drilling tool and a drilling method thereof. The drilling tool has a simple structure and can achieve the connection and isolation of the inner and outer annuli of the drill string. It can realize small-displacement drilling and large-displacement well washing. It uses the hydraulic pressurization function to increase the drilling pressure and improves the drilling efficiency by increasing the mechanical drilling speed of the drilling.

[0004] In traditional drilling operations, the drill bit pressure is only provided by the weight of the drill collar, so it is limited by the weight of the drill collar, the drilling pressure of the drill bit is often relatively small, and drilling is only performed through a single rotation grinding or impact, which makes it time-consuming and inefficient for traditional drilling tools to break deep rocks.

[0005] In view of this, the present invention provides a drilling tool and a drilling method. Summary of the invention

[0006] The present invention proposes a drilling tool and a drilling method, which solves the problem in the related art that in traditional drilling operations, the drilling pressure of the drill bit is often relatively small, and drilling is performed only through a single rotation grinding or impact, thereby making the traditional drilling tool inefficient in breaking deep rocks.

[0007] The technical solution of the present invention is as follows: a drilling tool, comprising: a mounting frame and a hollow prism penetrating the inner side of the mounting frame, wherein a driving device is arranged on the mounting frame for rotating the hollow prism;

[0008] The bottom of the hollow prism is detachably fixed with a drilling rod, and the inside of the drilling rod and the hollow prism are respectively sleeved with a splicing positioning tube and a top positioning tube, the bottom end of the splicing positioning tube is spliced ​​with the top end of the top positioning tube, and the bottom end of the splicing positioning tube is fixed with a positioning shaft;

[0009] A drill bit mechanism is provided at the bottom of the drilling rod, and the drill bit mechanism includes a composite drill bit, a fixing sleeve fixed to the outer wall of the drilling rod by fastening bolts, and a hollow sleeve for installing the composite drill bit. The top of the hollow sleeve is provided with an annular step matched with the positioning shaft, and an impact assembly is provided between the hollow sleeve and the fixing sleeve. When the drilling rod rotates with the hollow prism, the hollow sleeve can drive the composite drill bit to rotate and move back and forth up and down.

[0010] Preferably, the outer walls of the splicing positioning tube and the top positioning tube are both protruding outwards and provided with limiting rings, and the inner walls of the splicing positioning tube and the top positioning tube are both provided with annular grooves for the limiting rings to slide.

[0011] Preferably, the impact assembly includes a lifting sleeve slidably mounted on the inner side of the fixed sleeve, the lifting sleeve is fixedly connected to the hollow sleeve, a plurality of guide plates are fixedly connected to the outer wall of the lifting sleeve in a ring array, a guide groove for sliding of the guide plate is provided on the inner side of the fixed sleeve, a limiting cylinder is fixedly connected to the top end of the lifting sleeve, a cylinder cavity is provided at the bottom of the drilling rod, the limiting cylinder extends to the inside of the cylinder cavity and is slidably connected thereto, and a reset spring is connected between the top end of the lifting sleeve and the bottom end of the drilling rod.

[0012] Preferably, the composite drill bit includes a drill bit body, a plurality of water spray pipes are arranged on the outside of the drill bit body, a hollow threaded barrel is fixedly connected to the top of the drill bit body, and the hollow threaded barrel is detachably connected to the inside of the hollow casing via threads.

[0013] Preferably, a plug-in tube is fixedly connected to the bottom of the hollow prism, and a plug-in cavity for inserting the plug-in tube is opened at the top of the drilling rod, and the plug-in tube and the plug-in cavity are fixedly connected by bolts.

[0014] Preferably, a plurality of limiting plug posts are fixedly connected to the bottom end of the top positioning tube, and a plurality of limiting plug holes for inserting the limiting plug posts are provided at the bottom end of the splicing positioning tube.

[0015] Preferably, the driving device includes a motor fixedly mounted on the bottom of the mounting frame, the motor output shaft rotates through the interior of the mounting frame and is fixedly connected to a driving gear, one side of the driving gear is meshedly connected to a passive gear, and the passive gear is rotatably connected to the top of the mounting frame.

[0016] Preferably, the hollow prism passes through the interior of the passive gear, and the hollow prism is connected to the passive gear in a sliding and fitting manner.

[0017] Preferably, the top end of the top positioning tube is in a sealed state, and a hanging ring is fixedly connected to the top end of the top positioning tube, and a water injection pipe is fixedly connected to the upper outer wall of the top positioning tube.

[0018] A drilling method comprises the following steps:

[0019] Step 1: Fix the fixed casing to the lower outer wall of the drilling rod by tightening bolts, tighten the hollow threaded tube into the hollow casing, and complete the installation of the drill bit mechanism at the bottom of the drilling rod;

[0020] Step 2: When drilling, start the motor, the motor drives the active gear to rotate through its output shaft, the active gear drives the passive gear to rotate, the passive gear drives the hollow prism to rotate, and then the hollow prism can drive the drilling rod to rotate, so that the drilling rod can rotate the drill bit mechanism, and the composite drill bit on the drill bit mechanism performs rotary drilling on the foundation;

[0021] Step 3: During the process of rotating the hollow prism by the driving device, the external lifting device suspends the top positioning cylinder by the lifting ring, and it should be noted that during the process of rotating the hollow prism and the drilling rod, the top positioning cylinder is in a suspended state, and the top positioning cylinder itself will not rotate, and under the action of the limiting plug column and the limiting plug hole, the limiting plug column is inserted into the limiting plug hole, so that the splicing positioning cylinder is the same as the top positioning cylinder, and neither of them will rotate, and under the action of the limiting ring, the top positioning cylinder and the hollow prism, and the splicing positioning cylinder and the drilling rod will not be dislocated in the vertical direction;

[0022] Step 4: In the process of the drilling rod driving the fixed casing to rotate, under the action of the guide groove and the guide plate, the fixed casing drives the lifting sleeve to rotate, the lifting sleeve drives the hollow casing to rotate, and the hollow casing drives the annular step to rotate. Since the positions of the spliced ​​positioning cylinder and the drilling rod remain unchanged in the vertical direction, the positions of the positioning shaft and the drilling rod remain unchanged in the vertical direction, so that when the annular step rotates, it can drive the hollow casing to move up and down reciprocatingly in cooperation with the positioning shaft, drive the limit cylinder to move up and down inside the cylinder cavity, and drive the guide plate to slide back and forth in the guide groove, so that the composite drill bit can reciprocate up and down to perform impact crushing and drilling on the foundation;

[0023] Step 5. As the drill bit mechanism continues to drill, the positions of the hollow prism and the drilling rod continue to move downward, and the hollow prism slides down inside the passive gear. When the total length of the hollow prism and the drilling rod is not enough to support continued drilling, the top positioning cylinder is lifted by an external lifting device, the hollow prism and the drilling rod are separated, and a drill rod is installed between the hollow prism and the drilling rod.

[0024] The working principle and beneficial effects of the present invention are:

[0025] In the present invention, in the process of the drilling rod driving the fixed casing to rotate, under the action of the guide groove and the guide plate, the fixed casing drives the lifting sleeve to rotate, the lifting sleeve drives the hollow casing to rotate, and the hollow casing drives the annular step to rotate. Since the positions of the spliced ​​positioning cylinder and the drilling rod remain unchanged in the vertical direction, the positions of the positioning shaft and the drilling rod remain unchanged in the vertical direction. When the annular step rotates, it can drive the hollow casing to move back and forth up and down in cooperation with the positioning shaft, drive the limit cylinder to move up and down inside the cylinder cavity, and drive the guide plate to slide back and forth in the guide groove. Utilizing a principle similar to that of a shield machine, the composite drill bit can reciprocate up and down to impact and crush the foundation, and the rock strength is first reduced by stamping. Then, the composite drill bit can rotate, scrape and break the rock while reciprocating up and down, thereby greatly improving the drilling efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0027] Figure 1 A schematic diagram of the three-dimensional structure of a drilling tool proposed by the present invention;

[0028] Figure 2 A schematic diagram of a drilling tool assembly structure proposed by the present invention;

[0029] Figure 3 A schematic diagram of a partial cross-sectional structure of a drilling tool proposed by the present invention;

[0030] Figure 4 for Figure 3 The enlarged structural diagram at A in the middle;

[0031] Figure 5 for Figure 3 The enlarged structural diagram at B in the middle;

[0032] Figure 6 This is a schematic diagram of the structural composition of the drill bit mechanism proposed by the present invention;

[0033] Figure 7 This is a schematic diagram of the assembly structure of the top positioning tube and the splicing positioning tube proposed by the present invention;

[0034] In the figure: 1. mounting frame; 2. driving device; 21. driving gear; 22. motor; 23. driven gear; 3. hollow prism; 31. plug-in cylinder; 4. drilling rod; 41. plug-in cavity; 5. top positioning cylinder; 51. lifting ring; 52. water injection pipe; 53. limiting plug column; 6. drill bit mechanism; 61. composite drill bit; 611. hollow threaded cylinder; 612. drill bit body; 613. water spray pipe; 62. fixed sleeve; 63. hollow sleeve; 64. fastening bolt; 65. annular step; 66. impact assembly; 661. guide groove; 662. guide plate; 663. lifting sleeve; 664. cylinder cavity; 665. reset spring; 666. limiting cylinder; 7. splicing positioning cylinder; 71. limiting socket; 8. positioning shaft; 9. limiting ring. DETAILED DESCRIPTION

[0035] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] Example 1

[0037] See also Figure 1 , Figure 2 , Figure 3 , Figure 4 as well as Figure 7 A drilling tool comprises: a mounting frame 1 and a hollow prism 3 penetrating the inner side of the mounting frame 1, wherein a driving device 2 is arranged on the mounting frame 1 for rotating the hollow prism 3. A drilling rod 4 is detachably fixed to the bottom of the hollow prism 3, and a splicing positioning tube 7 and a top positioning tube 5 are respectively sleeved inside the drilling rod 4 and the hollow prism 3, wherein the bottom end of the splicing positioning tube 7 is spliced ​​with the top end of the top positioning tube 5, and a positioning shaft 8 is fixed to the bottom end of the splicing positioning tube 7.

[0038] Furthermore, the outer walls of the splicing positioning tube 7 and the top positioning tube 5 are both protruding outwards and are provided with a limiting ring 9, and the inner walls of the splicing positioning tube 7 and the top positioning tube 5 are both provided with annular grooves for the limiting ring 9 to slide. Under the joint action of the limiting ring 9 and the annular groove, no vertical displacement will occur between the top positioning tube 5 and the hollow prism 3, and between the splicing positioning tube 7 and the drilling rod 4, and the top positioning tube 5 and the hollow prism 3, and between the splicing positioning tube 7 and the drilling rod 4 can rotate smoothly.

[0039] Furthermore, a plug-in tube 31 is fixedly connected to the bottom of the hollow prism 3, and a plug-in cavity 41 is opened on the top of the drilling rod 4 for the plug-in tube 31 to be inserted. The plug-in tube 31 and the plug-in cavity 41 are fixedly connected by bolts, so that the hollow prism 3 and the drilling rod 4 are integrated and can be lifted and rotated together.

[0040] It should be noted that a plurality of limit plugs 53 are fixedly connected to the bottom end of the top positioning tube 5, and a plurality of limit plugs 71 for inserting the limit plugs 53 are provided at the bottom end of the splicing positioning tube 7. The top end of the top positioning tube 5 is in a sealed state, and a hanging ring 51 is fixedly connected to the top end of the top positioning tube 5, and a water injection pipe 52 is fixedly connected to the upper outer wall of the top positioning tube 5. Under the action of the limit plugs 53 and the limit plugs 71, the limit plugs 53 are inserted into the limit plugs 71, so that the splicing positioning tube 7 is the same as the top positioning tube 5. When the top positioning tube 5 is suspended by an external lifting device, neither the splicing positioning tube 7 nor the top positioning tube 5 will rotate.

[0041] In addition, the driving device 2 includes a motor 22 fixedly mounted at the bottom of the mounting frame 1, the output shaft of the motor 22 rotates and penetrates the interior of the mounting frame 1 and is fixedly connected to the driving gear 21, one side of the driving gear 21 is meshedly connected to the passive gear 23, and the passive gear 23 is rotatably connected to the top of the mounting frame 1. The hollow prism 3 penetrates the passive gear 23, and the hollow prism 3 is slidably connected to the passive gear 23. When drilling, the motor 22 is started, and the motor 22 drives the driving gear 21 to rotate through its output shaft, and the driving gear 21 drives the passive gear 23 to rotate, and the passive gear 23 drives the hollow prism 3 to rotate, and then the drilling rod 4 can be driven to rotate through the hollow prism 3.

[0042] Example 2

[0043] See also Figure 1 , Figure 3 , Figure 5 as well as Figure 6 A drilling tool includes all the contents of implementation 1. In addition, a drill bit mechanism 6 is arranged at the bottom of the drilling rod 4, and the drill bit mechanism 6 includes a composite drill bit 61, a fixed sleeve 62 fixed to the outer wall of the drilling rod 4 by a fastening bolt 64, and a hollow sleeve 63 for installing the composite drill bit 61. The top of the hollow sleeve 63 is provided with an annular step 65 that matches the positioning shaft 8. An impact assembly 66 is arranged between the hollow sleeve 63 and the fixed sleeve 62. When the drilling rod 4 rotates with the hollow prism 3, the hollow sleeve 63 can drive the composite drill bit 61 to rotate and move back and forth up and down.

[0044] Furthermore, the impact assembly 66 includes a lifting sleeve 663 slidably sleeved on the inner side of the fixed sleeve 62, the lifting sleeve 663 is fixedly connected to the hollow sleeve 63, a plurality of guide plates 662 are fixedly connected to the outer wall of the lifting sleeve 663 in a circular array, a guide groove 661 is provided on the inner side of the fixed sleeve 62 for the guide plate 662 to slide, a limiting cylinder 666 is fixedly connected to the top end of the lifting sleeve 663, a cylinder cavity 664 is provided at the bottom of the drilling rod 4, the limiting cylinder 666 extends to the inside of the cylinder cavity 664 and is slidably connected thereto, and a reset spring 665 is connected between the top end of the lifting sleeve 663 and the bottom end of the drilling rod 4.

[0045] Furthermore, the composite drill bit 61 includes a drill bit body 612, a plurality of water spray pipes 613 are arranged on the outside of the drill bit body 612, a hollow threaded barrel 611 is fixedly connected to the top of the drill bit body 612, and the hollow threaded barrel 611 is detachably connected to the inside of the hollow sleeve 63 through threads.

[0046] In this embodiment, in the process of the drilling rod 4 driving the fixed casing 62 to rotate, under the action of the guide groove 661 and the guide plate 662, the fixed casing 62 drives the lifting sleeve 663 to rotate, the lifting sleeve 663 drives the hollow casing 63 to rotate, and the hollow casing 63 drives the annular step 65 to rotate. Since the spliced ​​positioning cylinder 7 and the drilling rod 4 remain in the same position in the vertical direction, the positioning shaft 8 and the drilling rod 4 remain in the same position in the vertical direction. When the annular step 65 rotates, it can drive the hollow casing 63 to move back and forth up and down in cooperation with the positioning shaft 8, drive the limit cylinder 666 to move up and down inside the cylinder cavity 664, and drive the guide plate 662 to slide back and forth in the guide groove 661, so that the composite drill bit 61 can move back and forth up and down to perform impact crushing and drilling on the foundation.

[0047] Working principle and use process: First, the fixing sleeve 62 is fixed to the lower outer wall of the drilling rod 4 by tightening the bolts 64, and the hollow threaded tube 611 is tightened inside the hollow sleeve 63 to complete the installation of the drill bit mechanism 6 at the bottom of the drilling rod 4. When drilling, the motor 22 is started, and the motor 22 drives the driving gear 21 to rotate through its output shaft, and the driving gear 21 drives the passive gear 23 to rotate, and the passive gear 23 drives the hollow prism 3 to rotate, and then the drilling rod 4 can be driven to rotate through the hollow prism 3, so that the drilling rod 4 can rotate the drill bit mechanism 6, and the composite drill bit 61 on the drill bit mechanism 6 performs rotary drilling on the foundation.

[0048] In the process of rotating the hollow prism 3 by the driving device 2, the external lifting device (not shown in the figure, currently, a steel cable pulley is mostly used for lifting, which is the prior art and will not be described in detail here) suspends the top positioning cylinder 5 through the lifting ring 51, and it should be noted that in the process of rotating the hollow prism 3 and the drilling rod 4, the top positioning cylinder 5 is in a suspended state, and the top positioning cylinder 5 itself does not rotate (in the actual operation engineering, preferably, a vertical hole can be opened inside the top positioning cylinder 5, and a sliding sleeve can be set in the hole). The vertical rod is installed on the drilling equipment to prevent the top positioning cylinder 5 from rotating. Other conventional methods can also be used to limit the rotation of the top positioning cylinder 5, which will not be elaborated here). Under the action of the limiting plug 53 and the limiting socket 71, the limiting plug 53 is inserted into the limiting socket 71, so that the splicing positioning cylinder 7 is the same as the top positioning cylinder 5 and neither of them will rotate. Under the action of the limiting ring 9, no displacement will occur in the vertical direction between the top positioning cylinder 5 and the hollow prism 3, and between the splicing positioning cylinder 7 and the drilling rod 4.

[0049] In the process of the drilling rod 4 driving the fixed casing 62 to rotate, under the action of the guide groove 661 and the guide plate 662, the fixed casing 62 drives the lifting sleeve 663 to rotate, the lifting sleeve 663 drives the hollow casing 63 to rotate, and the hollow casing 63 drives the annular step 65 to rotate. Since the spliced ​​positioning cylinder 7 and the drilling rod 4 remain in the same position in the vertical direction, the positioning shaft 8 and the drilling rod 4 remain in the same position in the vertical direction, so that when the annular step 65 rotates, in cooperation with the positioning shaft 8, it can drive the hollow casing 63 to move up and down reciprocatingly, drive the limit cylinder 666 to move up and down inside the cylinder cavity 664, and drive the guide plate 662 to slide back and forth in the guide groove 661, so that the composite drill bit 61 can reciprocate up and down to perform impact crushing and drilling on the foundation.

[0050] As the drill bit mechanism 6 continues to drill, the positions of the hollow prism 3 and the drilling rod 4 continue to move downward, and the hollow prism 3 slides down inside the passive gear 23. When the total length of the hollow prism 3 and the drilling rod 4 is not enough to support continued drilling, the top positioning cylinder 5 is lifted by an external lifting device, the hollow prism 3 and the drilling rod 4 are separated, and a drill rod is installed between the hollow prism 3 and the drilling rod 4 (the shape and size of the drill rod can refer to the hollow prism 3 and the drilling rod 4, and the top and bottom ends of the drill rod can be respectively provided with an insert cavity 41 and an insert cylinder 31, the purpose of which is to install the drill rod between the hollow prism 3 and the drilling rod 4 to increase the drilling depth). During the drilling operation, drilling fluid is injected into the water injection pipe 52 through an external sludge pump (not shown in the figure), and the drilling fluid is transported to the drill bit body 612 through the top positioning tube 5, the spliced ​​positioning tube 7, and the hollow casing 63, and is sprayed out through the water spray pipe 613. Under the action of high pressure, the drilling fluid cleans the bottom of the well and transports the mud and rock cuttings to the wellhead.

[0051] It is worth noting that the circuits, electronic components and modules involved in the present invention are all prior art and can be fully implemented by those skilled in the art. Needless to say, the content protected by the present invention does not involve improvements to software and methods.

[0052] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A drilling tool comprising: A mounting frame (1) and a hollow prism (3) penetrating the inner side of the mounting frame (1), characterized in that a driving device (2) is provided on the mounting frame (1) for rotating the hollow prism (3); The bottom of the hollow prism (3) is detachably fixedly connected to a drilling rod (4); a splicing positioning tube (7) and a top positioning tube (5) are respectively sleeved inside the drilling rod (4) and the hollow prism (3); the bottom end of the splicing positioning tube (7) is spliced ​​with the top end of the top positioning tube (5); and a positioning shaft (8) is fixedly connected to the bottom end of the splicing positioning tube (7); A drill bit mechanism (6) is arranged at the bottom of the drilling rod (4), and the drill bit mechanism (6) comprises a composite drill bit (61), a fixing sleeve (62) fixed to the outer wall of the drilling rod (4) by means of a fixing bolt (64), and a hollow sleeve (63) for installing the composite drill bit (61). An annular step (65) matching with the positioning shaft (8) is arranged at the top of the hollow sleeve (63), and an impact assembly (66) is arranged between the hollow sleeve (63) and the fixing sleeve (62). When the drilling rod (4) rotates along with the hollow prism (3), the hollow sleeve (63) can drive the composite drill bit (61) to rotate and move back and forth up and down.

2. A drilling tool according to claim 1, characterized in that: The outer walls of the splicing positioning tube (7) and the top positioning tube (5) are both protruding outwards and provided with a limiting ring (9), and the inner walls of the splicing positioning tube (7) and the top positioning tube (5) are both provided with an annular groove for the limiting ring (9) to slide.

3. A drilling tool according to claim 2, characterized in that: The impact assembly (66) comprises a lifting sleeve (663) slidably sleeved on the inner side of the fixed sleeve (62); the lifting sleeve (663) is fixedly connected to the hollow sleeve (63); a plurality of guide plates (662) are fixedly connected to the outer wall of the lifting sleeve (663) in an annular array; a guide groove (661) for the guide plate (662) to slide is provided on the inner side of the fixed sleeve (62); a limiting cylinder (666) is fixedly connected to the top end of the lifting sleeve (663); a cylinder cavity (664) is provided at the bottom of the drilling rod (4); the limiting cylinder (666) extends into the cylinder cavity (664) and is slidably connected thereto; a return spring (665) is connected between the top end of the lifting sleeve (663) and the bottom end of the drilling rod (4).

4. A drilling tool according to claim 3, characterized in that: The composite drill bit (61) comprises a drill bit body (612), a plurality of water spray pipes (613) are arranged outside the drill bit body (612), a hollow threaded barrel (611) is fixedly connected to the top of the drill bit body (612), and the hollow threaded barrel (611) is detachably connected to the inside of the hollow sleeve (63) via threads.

5. A drilling tool according to claim 4, characterized in that: The bottom of the hollow prism (3) is fixedly connected with a plug-in tube (31), the top of the drilling rod (4) is provided with a plug-in cavity (41) for inserting the plug-in tube (31), and the plug-in tube (31) and the plug-in cavity (41) are fixedly connected by bolts.

6. A drilling tool according to claim 5, characterized in that: A plurality of limiting plug posts (53) are fixedly connected to the bottom end of the top positioning tube (5), and a plurality of limiting plug holes (71) for inserting the limiting plug posts (53) are provided at the bottom end of the splicing positioning tube (7).

7. A drilling tool according to claim 6, characterized in that: The driving device (2) comprises a motor (22) fixedly mounted on the bottom of the mounting frame (1); an output shaft of the motor (22) rotatably penetrates the interior of the mounting frame (1) and is fixedly connected to a driving gear (21); one side of the driving gear (21) is meshedly connected to a driven gear (23); and the driven gear (23) is rotatably connected to the top of the mounting frame (1).

8. A drilling tool according to claim 7, characterized in that: The hollow prism (3) penetrates the interior of the passive gear (23), and the hollow prism (3) is connected to the passive gear (23) in a sliding manner.

9. A drilling tool according to claim 8, characterized in that: The top end of the top positioning tube (5) is in a sealed state, and a hanging ring (51) is fixedly connected to the top end of the top positioning tube (5), and a water injection pipe (52) is fixedly connected to the upper outer wall of the top positioning tube (5).

10. A drilling method using a drilling tool as claimed in any one of claims 1 to 9, characterized in that: The following steps are involved: Step 1: fix the fixing sleeve (62) to the lower outer wall of the drilling rod (4) by tightening the bolts (64), and tighten the hollow threaded tube (611) into the hollow sleeve (63), so as to complete the installation of the drill bit mechanism (6) at the bottom of the drilling rod (4); Step 2: When drilling, the motor (22) is started, and the motor (22) drives the driving gear (21) to rotate through its output shaft, and the driving gear (21) drives the driven gear (23) to rotate, and the driven gear (23) drives the hollow prism (3) to rotate, and then the hollow prism (3) drives the drilling rod (4) to rotate, so that the drilling rod (4) can rotate the drill bit mechanism (6), and the composite drill bit (61) on the drill bit mechanism (6) performs rotary drilling on the foundation; Step 3: During the process of rotating the hollow prism (3) by the driving device (2), the external lifting device suspends the top positioning cylinder (5) through the lifting ring (51), and it should be noted that during the process of rotating the hollow prism (3) and the drilling rod (4), the top positioning cylinder (5) is in a suspended state, and the top positioning cylinder (5) itself does not rotate. Under the action of the limiting plug column (53) and the limiting plug hole (71), the limiting plug column (53) is inserted into the limiting plug hole (71), so that the splicing positioning cylinder (7) and the top positioning cylinder (5) are the same and do not rotate. Under the action of the limiting ring (9), there is no vertical displacement between the top positioning cylinder (5) and the hollow prism (3), and between the splicing positioning cylinder (7) and the drilling rod (4); Step 4: When the drilling rod (4) drives the fixed casing (62) to rotate, under the action of the guide groove (661) and the guide plate (662), the fixed casing (62) drives the lifting sleeve (663) to rotate, the lifting sleeve (663) drives the hollow casing (63) to rotate, and the hollow casing (63) drives the annular step (65) to rotate. Since the spliced ​​positioning tube (7) and the drilling rod (4) remain in the same position in the vertical direction, the positioning tube (7) and the drilling rod (4) are fixed. The shaft (8) and the drilling rod (4) remain in the same position in the vertical direction, so that when the annular step (65) rotates, in cooperation with the positioning shaft (8), it can drive the hollow casing (63) to move up and down, drive the limit cylinder (666) to move up and down inside the cylinder cavity (664), and drive the guide plate (662) to slide back and forth in the guide groove (661), so that the composite drill bit (61) can move up and down to perform impact crushing and drilling on the foundation; Step 5: As the drill bit mechanism (6) continues to drill, the positions of the hollow prism (3) and the drilling rod (4) continue to move downward, and the hollow prism (3) slides down inside the passive gear (23). When the total length of the hollow prism (3) and the drilling rod (4) is insufficient to support continued drilling, the top positioning cylinder (5) is lifted by an external lifting device, the hollow prism (3) and the drilling rod (4) are separated, and a drilling rod is installed between the hollow prism (3) and the drilling rod (4).

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