Length-adjustable anti-falling rod and screw drill

Abstract

The invention relates to a length-adjustable anti-falling rod and a screw drill, the length-adjustable anti-falling rod comprises an anti-falling rod body and an adjusting screw, the anti-falling rod body comprises a sliding sleeve and a sliding rod which are coaxial and are in sliding connection with each other, and threaded holes which are communicated with each other are formed in the sliding sleeve and the sliding rod; the adjusting screw penetrates through the threaded holes of the sliding sleeve and the sliding rod and is in threaded connection with the sliding sleeve and the sliding rod. Circumferential locking mechanisms are arranged between the sliding sleeve and the adjusting screw and between the sliding rod and the adjusting screw. One end of the adjusting screw rod is in threaded connection with the sliding sleeve, the other end of the adjusting screw rod is in threaded connection with the sliding rod, and the circumferential locking mechanisms are arranged between the sliding sleeve and the adjusting screw rod and between the sliding rod and the adjusting screw rod, so that the length of the anti-falling rod can be adjusted according to upper connectors of different sizes in the well drilling process; and the technical problem that the whole set of downhole tool needs to be replaced and efficient drilling cannot be performed due to the fact that the anti-falling rod with the fixed length interferes with the interior of the upper connector in the related technology is solved.

Description

Technical Field

[0001] The present application relates to the field of oil drilling tools, and in particular to a length-adjustable anti-drop rod and a screw drilling tool. Background Art

[0002] At present, anti-drop rods are commonly used in various oil and gas drilling downhole tools. Anti-drop rods can effectively prevent screw drill tools from falling into the well due to tripping or breakage, and play a role in preventing them from falling.

[0003] In related technologies, since the thread specifications of the upper joint often change during drilling, upper joints of different structural sizes are required. After the drilling tool is used, the thread often needs to be repaired on a lathe, resulting in the axial length of the drill tool becoming shorter. The fixed-length anti-drop rod interferes with the internal structure of the upper joint, resulting in the need to replace the entire set of downhole tools, making it impossible to drill efficiently.

[0004] Therefore, it is necessary to design a new anti-drop rod with adjustable length to overcome the problems mentioned above. Summary of the Invention

[0005] The present application provides an anti-drop rod and screw drilling tool with adjustable length, which can solve the technical problem in the related art that the fixed-length anti-drop rod interferes with the internal structure of the upper joint, resulting in the need to replace the entire set of downhole tools and inability to drill efficiently.

[0006] In the first aspect, an embodiment of the present application provides a length-adjustable anti-drop rod, which includes: an anti-drop rod body and an adjusting screw, the anti-drop rod body includes a coaxial sliding sleeve and a sliding rod that are slidably connected to each other, and the sliding sleeve and the sliding rod are both provided with threaded holes that are interconnected; the adjusting screw is passed through the threaded holes of the sliding sleeve and the sliding rod and are threadedly connected to each other, and a circumferential locking mechanism is provided between the sliding sleeve, the sliding rod and the adjusting screw.

[0007] In combination with the first aspect, in one embodiment, the sliding rod is penetrated by a first threaded hole, the adjusting screw is passed through the first threaded hole, and the adjusting screw is threadedly connected to the sliding rod, a second threaded hole is provided on one side of the sliding rod, the second threaded hole is connected to the first threaded hole, and the circumferential locking mechanism between the sliding rod and the adjusting screw is provided with a locking screw, the locking screw is passed through the second threaded hole, and the sliding rod and the adjusting screw are fixed by the locking screw.

[0008] In combination with the first aspect, in one embodiment, the axis of the first threaded hole is perpendicular to the axis of the second threaded hole.

[0009] In combination with the first aspect, in one embodiment, the sliding sleeve is penetrated by a third threaded hole, the adjusting screw is passed through the third threaded hole, and the adjusting screw is threadedly connected to the sliding sleeve, and a locking groove is provided at the end of the sliding sleeve away from the sliding rod, and the locking groove is connected to the third threaded hole, and the circumferential locking mechanism between the sliding sleeve and the adjusting screw is provided with a locking key, and the locking key is installed in the locking groove, and the sliding sleeve and the adjusting screw are circumferentially fixed by the locking key.

[0010] In combination with the first aspect, in one embodiment, a first positioning surface is provided on opposite sides of the adjusting screw, and the locking key is provided with a second positioning surface and a curved surface connected to each other, and the locking key is fitted with the first positioning surface through the second positioning surface, so that the sliding sleeve and the adjusting screw are circumferentially fixed.

[0011] In combination with the first aspect, in one embodiment, the sliding sleeve is provided with an inner hole, the inner hole is communicated with the third threaded hole, and the diameter of the inner hole is equal to the diameter of one end of the sliding rod close to the sliding sleeve.

[0012] In combination with the first aspect, in one embodiment, the adjusting screw is penetrated by a first threading hole.

[0013] In combination with the first aspect, in one embodiment, a sealing groove is provided at one end of the sliding rod close to the sliding sleeve, a sealing ring is installed in the sealing groove, and the sealing ring abuts against the sliding sleeve.

[0014] In a second aspect, an embodiment of the present application provides a screw drill, which includes: a drill housing and the above-mentioned anti-drop rod, wherein the anti-drop rod is installed in the drill housing.

[0015] In combination with the second aspect, in one embodiment, the drill tool housing includes an anti-drop housing and a stator housing that are coaxially connected, a flexible shaft is provided in the anti-drop housing, the flexible shaft is threadedly connected to the anti-drop rod, a rotor is provided in the stator housing, the rotor is threadedly connected to the anti-drop rod, the flexible shaft, the rotor and the anti-drop rod are coaxially arranged, the anti-drop rod is provided with a first wire threading hole, the flexible shaft and the rotor are both provided with a second wire threading hole, the first wire threading hole and the second wire threading hole are coaxially arranged, and cables are passed through the first wire threading hole and the second wire threading hole.

[0016] The beneficial effects of the technical solutions provided in the embodiments of the present application include: By threading a sliding sleeve at one end of the adjusting screw and threading a sliding rod at the other end of the adjusting screw, and by providing a circumferential locking mechanism between the sliding sleeve and the adjusting screw and between the sliding rod and the adjusting screw, the anti-drop rod can be adjusted in length according to upper joints of different sizes during drilling, without the need to replace the entire downhole tool. This solves the technical problem in the related art that a fixed-length anti-drop rod interferes with the interior of the upper joint, resulting in the need to replace the entire downhole tool and inability to drill efficiently. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0018] Figure 1 A schematic diagram of a threading and anti-drop rod provided in an embodiment of the present application; Figure 2 A schematic diagram of a sliding sleeve provided in an embodiment of the present application; Figure 3 A side view of a sliding sleeve provided in an embodiment of the present application; Figure 4 A schematic diagram of a sliding bar provided in an embodiment of the present application; Figure 5 A schematic diagram of an adjusting screw provided in an embodiment of the present application; Figure 6 A cross-sectional view of an adjusting screw provided in an embodiment of the present application; Figure 7 A schematic diagram of a locking screw provided in an embodiment of the present application; Figure 8 A schematic diagram of a locking key provided in an embodiment of the present application; Figure 9 Schematic diagram of the screw drill provided in an embodiment of the present application.

[0019] In the figure: 1. Sleeve; 11. Third threaded hole; 12. Locking groove; 13. Inner hole; 14. Third positioning surface; 2. Sliding rod; 21. First threaded hole; 22. Second threaded hole; 23. Sealing groove; 24. Fourth positioning surface; 25. Guide angle; 3. Adjusting screw; 31. First positioning surface; 32. First threading hole; 4. Locking screw; 5. Locking key; 51. Second positioning surface; 52. Curved surface; 6. Sealing ring; 7. Drill tool housing; 71. Anti-drop housing; 72. Stator housing; 8. Flexible shaft; 9. Rotor; 10. Cable. DETAILED DESCRIPTION

[0020] In order to enable those skilled in the art to better understand the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. 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 this application.

[0021] The embodiment of the present application provides a length-adjustable anti-drop rod and screw drilling tool, which can solve the problem that the fixed-length anti-drop rod interferes with the internal structure of the upper joint, resulting in the need to replace the entire set of downhole tools and the inability to drill efficiently.

[0022] See also Figure 1 As shown, an embodiment of the present application provides an anti-drop rod with adjustable length, which includes: an anti-drop rod body and an adjusting screw 3, the anti-drop rod body includes a coaxial sliding sleeve 1 and a sliding rod 2 that are slidably connected to each other, and the sliding sleeve 1 and the sliding rod 2 are both provided with threaded holes that are connected to each other; the adjusting screw 3 is passed through the threaded holes of the sliding sleeve 1 and the sliding rod 2 and are threadedly connected to each other, and a circumferential locking mechanism is provided between the sliding sleeve 1, the sliding rod 2 and the adjusting screw 3.

[0023] The cam 1 is connected to the adjusting screw 3 by a threaded connection to the sleeve 1, and the lower end of the adjusting screw 3 is connected to the sliding rod 2 by a threaded connection to the adjusting screw 3. The sliding sleeve 1 and the sliding rod 2 slide relative to each other on the adjusting screw 3, so that the length of the anti-drop rod can be adjusted. The sliding sleeve 1 and the adjusting screw 3 are circumferentially fixed by the circumferential locking mechanism, and the sliding sleeve 1 and the adjusting screw 3 are fixed by the circumferential locking mechanism to ensure that the anti-drop rod can be maintained at a set length during drilling and is not unlocked with its own rotation and revolution. The anti-drop rod can be adjusted in length according to upper joints of different sizes during drilling without replacing the entire set of downhole tools, quickly responding to drilling project needs and shortening drilling cycles. The torque of the anti-drop rod during drilling is generally 10,000~20,000Nm, and the tension that the anti-drop rod needs to bear is generally 100~300T. Conventional pin connections and snap connections cannot withstand large torques and tensions.

[0024] This embodiment makes the length of the anti-drop rod adjustable by threading the sleeve 1 at one end of the adjusting screw 3 and threading the sliding rod 2 at the other end of the adjusting screw 3, and by arranging the circumferential locking mechanism between the sliding sleeve 1 and the adjusting screw 3 and between the sliding rod 2 and the adjusting screw 3, it ensures that the anti-drop rod is maintained at the set length during the drilling process, so that the anti-drop rod can be adjusted in length according to upper joints of different sizes during the drilling process without replacing the entire set of downhole tools, thereby solving the technical problem in the related art that the fixed-length anti-drop rod interferes with the internal structure of the upper joint, resulting in the need to replace the entire set of downhole tools and inability to drill efficiently.

[0025] Further, see Figure 1 and Figure 4 As shown, in some embodiments, the sliding rod 2 is penetrated by a first threaded hole 21, the adjusting screw 3 is passed through the first threaded hole 21, and the adjusting screw 3 is threadedly connected to the sliding rod 2, and a second threaded hole 22 is provided on one side of the sliding rod 2, and the second threaded hole 22 is connected to the first threaded hole 21, and the circumferential locking mechanism between the sliding rod 2 and the adjusting screw 3 is provided with a locking screw 4, the locking screw 4 is passed through the second threaded hole 22, and the sliding rod 2 and the adjusting screw 3 are fixed by the locking screw 4.

[0026] In this embodiment, the locking screw 4 is pressed against the adjusting screw 3 to fix the sliding rod 2 and the adjusting screw 3, so that the anti-drop rod is maintained at a required length. The diameter of the second threaded hole 22 is equal to the diameter of the locking screw 4. The number of the second threaded holes 22 can be set to one, two or more. Further, see Figure 1 and Figure 4 As shown, in some embodiments, the axis of the first threaded hole 21 is perpendicular to the axis of the second threaded hole 22 .

[0027] In this embodiment, the axis of the first threaded hole 21 and the axis of the second threaded hole 22 can be arranged perpendicularly, ensuring that the bottom surface of the locking screw 4 can abut the first positioning surface 31 of the adjusting screw 3, thereby securing the sliding rod 2 and the adjusting screw 3 and preventing them from loosening due to rotation or revolution during the anti-drop drilling process. In other embodiments, the axis of the first threaded hole 21 and the axis of the second threaded hole 22 can be arranged at an angle.

[0028] Further, see Figure 1-3 and Figure 8As shown, in some embodiments, the sleeve 1 is penetrated by a third threaded hole 11, the adjusting screw 3 is inserted into the third threaded hole 11, and the adjusting screw 3 is threadedly connected to the sleeve 1, and the end of the sleeve 1 away from the slide rod 2 is provided with a locking groove 12, and the locking groove 12 is communicated with the third threaded hole 11, and the circumferential locking mechanism between the sleeve 1 and the adjusting screw 3 is provided with a locking key 5, and the locking key 5 is installed in the locking groove 12, and the sleeve 1 and the adjusting screw 3 are circumferentially fixed by the locking key 5.

[0029] In this embodiment, the third threaded hole 11 is coaxially arranged with the first threaded hole 21, and the diameter of the third threaded hole 11 can be set to be equal to the diameter of the first threaded hole 21. The shape of the locking groove 12 is adapted to the curved surface 52 of the locking key 5. The locking key 5 can be set to a square key or a semicircular key or a locking key 5 of other shapes, and the locking groove 12 can be set to a square groove or a semicircular groove or a locking groove 12 of other shapes. Preferably, the locking key 5 is set to a semicircular key, and the locking groove 12 is set to a semicircular groove to facilitate processing. The semicircular key is installed in the semicircular groove, and the sleeve 1 and the adjusting screw 3 are circumferentially fixed by the semicircular key.

[0030] Further, see Figure 1 、 Figure 5 、 Figure 6 and Figure 8 As shown, in some embodiments, the adjusting screw 3 is provided with a first positioning surface 31 on opposite sides, and the locking key 5 is provided with a second positioning surface 51 and a curved surface 52 that are connected to each other. The locking key 5 is fitted with the first positioning surface 31 through the second positioning surface 51, so that the sliding sleeve 1 and the adjusting screw 3 are circumferentially fixed.

[0031] In this embodiment, when the second positioning surface 51 is in contact with the first positioning surface 31, the upper end of the sliding sleeve 1 is circumferentially fixed to the adjusting screw 3, and the curved surface 52 can be set to a semicircular surface, a rectangular surface, or other curved surfaces. When the second positioning surface 51 is pressed against the bottom surface of the locking screw 4, the lower end of the sliding rod 2 is fixed to the adjusting screw 3, and the anti-drop rod is maintained at the required length.

[0032] Further, see Figure 1 and Figure 2 As shown, in some embodiments, the sliding sleeve 1 is provided with an inner hole 13 , the inner hole 13 is connected to the third threaded hole 11 , and the diameter of the inner hole 13 is equal to the diameter of one end of the sliding rod 2 close to the sliding sleeve 1 .

[0033] In this embodiment, the sliding sleeve 1 is rotated and the adjusting screw 3 is driven to rotate, so that the sliding rod 2 can move up and down along the axis of the adjusting screw 3, thereby realizing the adjustable length of the anti-drop rod. The end of the sliding rod 2 is inserted into the inner hole 13 of the sliding sleeve 1, and the end of the sliding rod 2 moves in the inner hole 13, so that the sliding rod 2 and the sliding sleeve 1 form a whole, thereby ensuring the integrity of the anti-drop rod.

[0034] Further, see Figure 1 、 Figure 5 and Figure 6 As shown, in some embodiments, the adjusting screw 3 is penetrated by a first threading hole 32 .

[0035] In this embodiment, the first threading hole 32 is coaxially arranged with the adjusting screw 3, and the diameter of the first threading hole 32 is set to 3~5㎜. The first threading hole 32 is used to accommodate the cable 10 to ensure that the cable 10 is not affected by the rotation and revolution of the anti-drop rod, and the electrical energy or electrical signal is stably transmitted by wire.

[0036] Further, see Figure 1 and Figure 4 As shown, in some embodiments, a sealing groove 23 is provided at one end of the sliding rod 2 close to the sliding sleeve 1 , a sealing ring 6 is installed in the sealing groove 23 , and the sealing ring 6 abuts against the sliding sleeve 1 .

[0037] In this embodiment, the sliding sleeve 1 and the sliding rod 2 are sealed and connected by the sealing ring 6, which ensures the overall sealing of the anti-drop rod during the drilling process, improves the service life of the anti-drop rod and the stability of the power or electrical signal transmission. The end of the sliding rod 2 is provided with a guide angle 25, and the guide angle 25 guides the sliding rod 2 during the process of adjusting it into the sliding sleeve 1, ensuring that the sliding rod 2 slides smoothly into the sliding sleeve 1.

[0038] When installing the anti-drop rod, screw the adjusting screw 3 into the sliding sleeve 1 until the top surface of the adjusting screw 3 is flush with the top surface of the sliding sleeve 1, then install the locking key 5 in the locking groove 12, dock the second positioning surface 51 of the locking key 5 with the first positioning surface 31 of the adjusting screw 3, so that the sliding sleeve 1 and the adjusting screw 3 are fixed circumferentially, then install the sealing ring 6 in the sealing groove 23, and then adjust the adjusting screw 3 into the sliding rod 2, rotate the sliding sleeve 1 to move the sliding rod 2 upward, until the anti-drop rod is installed. The sealing ring 6 is located in the inner hole 13 of the sleeve 1. Continue to rotate the sleeve 1 until the anti-drop rod is adjusted to the required length. The required length of the anti-drop rod can be read by the distance between the third positioning surface 14 of the sleeve 1 and the fourth positioning surface 24 of the slide rod 2. Finally, screw the locking screw 4 into the second threaded hole 22 of the sleeve 1. The bottom surface of the locking screw 4 presses against the first positioning surface 31 to fix the slide rod 2 and the adjusting screw 3, ensuring that the anti-drop rod can be maintained at the set length during drilling.

[0039] When it is necessary to replace the upper joint with a different length specification, loosen the locking screw 4, and then rotate the sleeve 1. When the distance between the third positioning surface 14 of the sleeve 1 and the fourth positioning surface 24 of the slide rod 2 is adjusted to the required length, screw in the locking screw 4 so that the bottom surface of the locking screw 4 is pressed against the first positioning surface 31, the slide rod 2 is fixed to the adjusting screw 3, and the length of the anti-drop rod is adjusted to the required length, so that the length of the anti-drop rod can be adjusted.

[0040] See also Figure 1 and Figure 9 As shown, an embodiment of the present application provides a screw drill, which includes: a drill housing 7 and the above-mentioned anti-drop rod, and the anti-drop rod is installed in the drill housing 7.

[0041] In this embodiment, the anti-drop rod is installed in the drill tool housing 7, the upper end of the adjusting screw 3 is threadedly connected to the sliding sleeve 1, and the lower end of the adjusting screw 3 is threadedly connected to the sliding rod 2. The sliding sleeve 1 and the sliding rod 2 slide relative to each other on the adjusting screw 3, so that the length of the anti-drop rod is adjustable, and the sliding sleeve 1 and the adjusting screw 3 are circumferentially fixed by the circumferential locking mechanism. The sliding sleeve 1 and the adjusting screw 3 are fixed by the circumferential locking mechanism, ensuring that the anti-drop rod can be maintained at the set length during drilling and will not be unlocked with its own rotation and revolution, so that the anti-drop rod can be adjusted in length according to upper joints of different sizes during drilling, without the need to replace the entire set of downhole tools, quickly responding to drilling project needs, and shortening the drilling cycle.

[0042] Further, see Figure 1 、 Figure 6 and Figure 9 As shown, in some embodiments, the drill tool housing 7 includes an anti-drop housing 71 and a stator housing 72 that are coaxially connected. A flexible shaft 8 is provided in the anti-drop housing 71, and the flexible shaft 8 is threadedly connected to the anti-drop rod. A rotor 9 is provided in the stator housing 72, and the rotor 9 is threadedly connected to the anti-drop rod. The flexible shaft 8, the rotor 9 and the anti-drop rod are coaxially arranged, and the anti-drop rod is provided with a first threading hole 32. The flexible shaft 8 and the rotor 9 are both provided with a second threading hole. The first threading hole 32 and the second threading hole are coaxially arranged, and cables 10 are passed through the first threading hole 32 and the second threading hole.

[0043] In this embodiment, the length of the anti-drop rod can be adjusted by loosening the locking screw 4 and rotating the sliding sleeve 1. The locking screw 4 can be screwed in so that the bottom surface of the locking screw 4 is pressed against the first positioning surface 31, so that the anti-drop rod can be maintained at the required length without replacing the entire downhole tool. The anti-drop shell 71 is located at the top of the stator shell 72. The anti-drop shell 71 and the stator shell 72 are both hollow tube structures. The anti-drop rod connects the flexible shaft 8 and the rotor 9. The flexible shaft 8 converts the eccentric motion of the rotor 9 into fixed axis motion. The rotation of the rotor 9 drives the anti-drop rod to rotate. A control system is provided above the flexible shaft 8, and a rotary guide system is provided below the rotor 9. The cable 10 is connected to the control system through the second threading hole of the flexible shaft 8, and the cable 10 is connected to the rotary guide system through the second threading hole of the rotor 9, thereby ensuring the stability of the wired connection between the screw drill and the external system during drilling.

[0044] In the description of this application, it should be noted that the terms "upper" and "lower" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application. Unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be internal communication between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0045] It should be noted that, in this application, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprising a ..." does not exclude the presence of other identical elements in the process, method, article or device comprising the element.

[0046] The foregoing is merely a list of specific embodiments of the present application, intended to enable those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application is not limited to the embodiments shown herein, but is intended to conform to the broadest scope consistent with the principles and novel features of the present application.

Claims

1. A length-adjustable anti-drop rod, characterized in that: It includes: The anti-drop rod body comprises a sliding sleeve (1) and a sliding rod (2) which are coaxial and slidably connected to each other, wherein the sliding sleeve (1) and the sliding rod (2) are both provided with threaded holes which are connected to each other; An adjusting screw (3) is inserted into the threaded holes of the sliding sleeve (1) and the sliding rod (2) and is threadedly connected to each other. A circumferential locking mechanism is provided between the sliding sleeve (1), the sliding rod (2) and the adjusting screw (3).

2. The anti-drop rod according to claim 1, characterized in that: The slide rod (2) is penetrated by a first threaded hole (21), the adjusting screw (3) is passed through the first threaded hole (21), and the adjusting screw (3) is threadedly connected to the slide rod (2), and a second threaded hole (22) is provided on one side of the slide rod (2), and the second threaded hole (22) is communicated with the first threaded hole (21). The circumferential locking mechanism between the slide rod (2) and the adjusting screw rod (3) is provided with a locking screw (4), the locking screw (4) is passed through the second threaded hole (22), and the slide rod (2) and the adjusting screw rod (3) are fixed by the locking screw (4).

3. The anti-drop rod according to claim 2, characterized in that: The axis of the first threaded hole (21) is arranged perpendicular to the axis of the second threaded hole (22).

4. The anti-drop rod according to claim 1, wherein: The sliding sleeve (1) is penetrated by a third threaded hole (11), the adjusting screw (3) is passed through the third threaded hole (11), and the adjusting screw (3) is threadedly connected to the sliding sleeve (1), and a locking groove (12) is provided at one end of the sliding sleeve (1) away from the sliding rod (2), and the locking groove (12) is communicated with the third threaded hole (11). The circumferential locking mechanism between the sliding sleeve (1) and the adjusting screw (3) is provided with a locking key (5), the locking key (5) is installed in the locking groove (12), and the sliding sleeve (1) and the adjusting screw (3) are circumferentially fixed via the locking key (5).

5. The anti-drop rod according to claim 4, characterized in that: The adjusting screw (3) is provided with first positioning surfaces (31) on opposite sides, and the locking key (5) is provided with a second positioning surface (51) and a curved surface (52) connected to each other. The locking key (5) is fitted with the first positioning surface (31) via the second positioning surface (51), so that the sliding sleeve (1) and the adjusting screw (3) are circumferentially fixed.

6. The anti-drop rod according to claim 4, characterized in that: The sliding sleeve (1) is provided with an inner hole (13), the inner hole (13) is communicated with the third threaded hole (11), and the diameter of the inner hole (13) is equal to the diameter of one end of the sliding rod (2) close to the sliding sleeve (1).

7. The anti-drop rod according to claim 1, characterized in that: The adjusting screw (3) is penetrated by a first threading hole (32).

8. The anti-drop rod according to claim 1, wherein: A sealing groove (23) is provided at one end of the sliding rod (2) close to the sliding sleeve (1), a sealing ring (6) is installed in the sealing groove (23), and the sealing ring (6) abuts against the sliding sleeve (1).

9. A screw drill, characterized in that: It includes: A drilling tool housing (7) and an anti-drop rod according to any one of claims 1 to 8, wherein the anti-drop rod is installed in the drilling tool housing (7).

10. The screw drill according to claim 9, characterized in that: The drilling tool housing (7) comprises a coaxially connected anti-drop housing (71) and a stator housing (72); a flexible shaft (8) is provided in the anti-drop housing (71); the flexible shaft (8) is threadedly connected to the anti-drop rod; a rotor (9) is provided in the stator housing (72); the rotor (9) is threadedly connected to the anti-drop rod; the flexible shaft (8), the rotor (9) and the anti-drop rod are coaxially arranged. The anti-drop rod is provided with a first threading hole (32), and the flexible shaft (8) and the rotor (9) are both provided with a second threading hole. The first threading hole (32) and the second threading hole are coaxially arranged, and cables (10) are passed through the first threading hole (32) and the second threading hole.

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