CN221691159U - Adjustable expansion drill - Google Patents

Abstract

The utility model discloses an adjustable expansion drill, which belongs to the technical field of medical appliances, and comprises a connecting sleeve and an inner core, wherein a cutting edge is hinged at the front end of the inner core in the connecting sleeve, a guide block for guiding the cutting edge is arranged at the inner side of the front end of the connecting sleeve, and a cutter groove for extending the cutting edge is arranged at the side surface of the front part of the connecting sleeve; the rear part of the adjustable expansion drill is provided with an adjusting device, and the adjusting device can drive the inner core to axially move in the connecting sleeve, so that the cutting edge is in abutting fit with the guide block, and the cutting edge can rotate and extend out of the cutter groove. The adjustable expansion drill can randomly adjust and control the opening angle of the cutter head, has small drilling diameter and meets the requirement of bone grafting.

Description

Adjustable expansion drill

Technical Field

The utility model relates to the technical field of medical instruments, in particular to an adjustable expansion drill.

Background

The expanding drill is a common medical instrument used for femoral head necrosis, cruciate ligament replacement, osteonecrosis removal and the like. The prior expanding drill has various types, such as an utility model patent CN2643846Y discloses a marrow cavity pressure reducing device for the ischemic necrosis operation of the femoral head, an utility model patent CN203089282U discloses a rotary scraper for the minimally invasive expanded marrow core pressure reducing reduction of the collapse femoral head necrosis, and an utility model patent CN217793221U discloses a bone drill which is used positively and negatively.

The existing expansion drill generally adopts an arc-shaped drill bit, a memory alloy cutter bit, a fixed-angle expansion drill and a common drill bit. These approaches have the following problems at the time of surgery: 1) The cutter head angle is fixed, the resistance is large, and the cutting is difficult; 2) The opening angle of the blade is limited, the blade can not be cut cleanly, or the angle of the cutting edge is too large, so that the tissue is easy to cut off and healthy without cutting off; 3) The blade is not easy to recycle; 4) The cutting holes do not meet the bone grafting requirements.

Disclosure of utility model

The utility model aims to solve the technical problem of providing the adjustable expansion drill which can be used for randomly adjusting and controlling the angle of the cutter head, has small diameter of a drill hole and meets the requirements of bone grafting.

In order to solve the technical problems, the utility model provides the following technical scheme:

An adjustable expansion drill, includes that the head end is confined adapter sleeve and is located in the adapter sleeve and with adapter sleeve sliding connection's inner core, wherein:

The front end of the inner core is hinged with a cutting edge in the connecting sleeve, a guide block for guiding the cutting edge is arranged on the inner side of the front end of the connecting sleeve, and a cutter groove for the cutting edge to extend out is formed in the side face of the front part of the connecting sleeve;

The rear part of the adjustable expansion drill is provided with an adjusting device, and the adjusting device can drive the inner core to axially move in the connecting sleeve so that the cutting edge is in abutting fit with the guide block, and the cutting edge can rotate and extend out of the cutter groove.

Further, on the terminal surface that the guide block and cutting edge are both relative, be equipped with the arc guide way on one, be equipped with on the other with arc guide way matched with arc guide way, wherein:

the arc-shaped guide groove and the arc-shaped guide table are both T-shaped;

And/or the side surface of the front end of the guide block is provided with a radially extending limit column, and the front end of the connecting sleeve is provided with a fixing groove matched with the limit column;

And/or the knife groove is a T-shaped groove.

Further, the front end of the inner core is provided with an oblique sliding groove, and the cutting edge is hinged in the sliding groove;

And/or the front part of the inner core is provided with an axially extending limit groove, a limit hole is arranged at a position on the connecting sleeve corresponding to the limit groove, and limit pins are arranged in the limit groove and the limit hole in a penetrating manner;

And/or the rear end of the inner core is in a triangular structure.

Further, the adjusting device includes a fixed block located at the rear of the connecting sleeve, a rotating block located at the rear of the fixed block, and an adjusting knob located on the rotating block, wherein:

The inner core sequentially passes through the connecting sleeve, the fixed block and the rotating block;

The rear end of the connecting sleeve is fixedly arranged on the fixed block, the rotating block is in driving connection with the inner core, the inner core is axially fixed and circumferentially rotatable and assembled on the fixed block, and the adjusting knob can drive the inner core to axially move in the connecting sleeve through the rotating block.

Further, a spiral groove is formed in a portion, corresponding to the rotating block, of the inner core, a guide pin is radially arranged at a position, corresponding to the spiral groove, on the inner side wall of the rotating block, and the tail end of the guide pin extends into the spiral groove;

And/or, the opposite end surfaces of the fixed block and the rotating block are provided with a plug hole, one of the end surfaces is provided with a plug section matched with the plug hole, the plug section is provided with an annular groove, the side wall of the plug hole is provided with a rotating hole at a position corresponding to the annular groove, the rotating hole is internally provided with a rotating pin, and the tail end of the rotating pin extends into the annular groove.

Further, the adjusting knob is of a cylindrical structure sleeved on the rotating block, a plug installation cavity is formed in the rear portion of the adjusting knob, a plug which is circumferentially fixed and axially slidable is arranged in the plug installation cavity, and the plug is fixedly arranged at the rear end of the rotating block.

Further, the adjusting device is further provided with a locking device for locking the relative positions of the adjusting knob and the fixed block, wherein:

the front end of the adjusting knob is provided with a fixed block installation cavity for accommodating the rear end of the fixed block, and the locking device comprises a first limiting tooth positioned on the inner side wall of the fixed block installation cavity and a second limiting tooth positioned on the outer surface of the rear end of the fixed block and matched with the first limiting tooth.

Further, an annular baffle is arranged on the inner side wall of the front part of the adjusting knob, a spring is sleeved on the rotating block, one end of the spring abuts against the plug, and the other end of the spring abuts against the annular baffle.

Further, be equipped with the through-hole that is used for holding rotatory piece rear end on the end cap, wherein:

The inner side wall of the through hole and the side surface of the rear end of the rotating block are provided with a limiting table, and one of the two is provided with a limiting groove matched with the limiting table;

And/or, the inner side wall of the through hole and the side surface of the rear end of the rotating block are respectively provided with a mutually matched seam-riding threaded hole, and a threaded jackscrew is arranged in the seam-riding threaded hole.

Further, the fixed block is provided with scales corresponding to the diameters of the expansion drills and the reaming holes;

And/or the front part of the fixed block is provided with a stepped hole, and the connecting sleeve is inserted and fixed in the stepped hole.

The utility model has the following beneficial effects:

The adjustable expansion drill comprises the connecting sleeve with the closed head end (namely, the sealing design) and the inner core which is connected in the connecting sleeve in a sliding manner, so that excessive cutting can be avoided, the adjustable expansion drill is prevented from being too deep, and bones are protected; the front end of the inner core in the connecting sleeve is hinged with a cutting edge, and a guide block for guiding the cutting edge is arranged on the inner side of the front end of the connecting sleeve, so that the cutting edge can be conveniently guided, and meanwhile, the head end of the connecting sleeve is sealed; the front side of the connecting sleeve is provided with a cutter groove for the cutting edge to extend out, the rear part of the adjustable expansion drill is provided with an adjusting device capable of driving the inner core to axially move in the connecting sleeve, so that the cutting edge is in butt fit with the guide block, and accordingly, the cutting edge can rotate and extend out of the cutter groove.

Drawings

FIG. 1 is a schematic view of the overall structure of an adjustable expansion drill of the present utility model;

FIG. 2 is a schematic cross-sectional view of an adjustable expansion drill according to the present utility model;

FIG. 3 is a schematic view of the guide block of FIG. 1, wherein (a) is a front view, (B) is a left side view of (a), (c) is a cross-sectional view of (B) along the B-B direction, and (d) is a top view of (a);

Fig. 4 is a schematic view of the cutting edge of fig. 1, wherein (a) is a front view, (b) is a bottom view of (a), and (c) is a right side view of (a);

FIG. 5 is a schematic view of the pin in FIG. 1;

FIG. 6 is a schematic view of the core of FIG. 1, wherein (a) is a front view and (b) is a top view of (a);

FIG. 7 is a schematic view of the connection sleeve of FIG. 1, wherein (a) is a front view and (b) is a top cross-sectional view of (a);

FIG. 8 is a schematic view of the structure of the fixing block in FIG. 1, wherein (a) is a front view, (b) is a left side view of (a), and (c) is a cross-sectional view of (b) along A-A direction;

FIG. 9 is a schematic view of the rotary block of FIG. 1, wherein (a) is a front view, (b) is a cross-sectional view of (a) along the direction C-C, and (C) is a right side view of (a);

FIG. 10 is a schematic view of the structure of the adjusting knob of FIG. 1, wherein (a) is a front view, (b) is a sectional view of (a), and (c) is a right side view of (a);

FIG. 11 is a schematic view of the plug of FIG. 1, wherein (a) is a front view and (b) is a cross-sectional view of (a) along the direction D-D;

Fig. 12 is a schematic view of the spring of fig. 1.

Detailed Description

In order to make the technical problems, technical solutions and advantages to be solved more apparent, the following detailed description will be given with reference to the accompanying drawings and specific embodiments.

In the description of the present utility model, it should be understood that the directions or positional relationships indicated by the terms "upper", "lower", "front", "rear", "left", "right", etc., are based on the directions or positional relationships shown in the drawings, are merely for convenience of describing the present utility model and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present utility model.

The utility model provides an adjustable expansion drill, as shown in figures 1-12, comprising a connecting sleeve 1 with a closed head end and an inner core 2 which is positioned in the connecting sleeve 1 and is in sliding connection with the connecting sleeve 1, wherein:

The front end of the inner core 2 in the connecting sleeve 1 is hinged (specifically, a pin shaft 21 can be adopted for hinging, in the specific implementation, a through hole 31 for the pin shaft 21 to pass through can be formed in the cutting edge 3, the cutting edge 3 can rotate around the pin shaft 21), the cutting edge 3 is arranged in the connecting sleeve 1, a guide block 4 for guiding the cutting edge 3 is arranged at the inner side of the front end of the connecting sleeve 1, and a cutter groove 11 for the cutting edge 3 to extend is formed in the side surface of the front part of the connecting sleeve 1;

The rear part of the adjustable expansion drill is provided with an adjusting device which can drive the inner core 2 to axially move in the connecting sleeve 1, so that the cutting edge 3 is in abutting fit with the guide block 4, and the cutting edge 3 can rotate and extend out of the cutter groove 11.

The adjustable expansion drill comprises the connecting sleeve with the closed head end (namely, the sealing design) and the inner core which is connected in the connecting sleeve in a sliding manner, so that excessive cutting can be avoided, the adjustable expansion drill is prevented from being too deep, and bones are protected; the front end of the inner core in the connecting sleeve is hinged with a cutting edge, and a guide block for guiding the cutting edge is arranged on the inner side of the front end of the connecting sleeve, so that the cutting edge can be conveniently guided, and meanwhile, the head end of the connecting sleeve is sealed; compared with the prior art, the adjustable expansion drill has the advantages that the adjusting device is controlled to drive the inner core to axially move in the connecting sleeve, so that the cutting blade can rotate and extend out of the cutter groove, and the cutting blade can rotate and extend out of the cutter groove, so that the opening angle of the control cutter head (namely the cutting blade) can be adjusted and controlled at will, the requirements of cutting holes with different diameters are met, the diameter of the drilled holes is small, the diameter of the cut holes is large, the external diameter is small, filled materials are not easy to flow out, the requirements of bone grafting are met, the replacement time of joints (such as hip joints) is avoided or delayed, and the structure is reliable.

As shown in fig. 3-4, one of the opposite end surfaces of the guide block 4 and the cutting edge 3 may be provided with an arc guide groove 41, and the other one is provided with an arc guide table 32 matched with the arc guide groove 41, and the arc guide table 32 slides in the arc guide groove 41 so as to guide the cutting edge 3 conveniently, so that the cutting edge 3 smoothly extends out of the cutter groove 11. In the embodiment shown in the figures, the guide block 4 is provided with an arc-shaped guide groove 41, and the cutting edge 3 is provided with an arc-shaped guide table 32.

Both the arcuate guide slot 41 and the arcuate guide table 32 may be T-shaped to prevent both from backing out. As shown in fig. 3 and 7, the side surface of the front end of the guide block 4 may be provided with a radially extending limit post 42, the front end of the connecting sleeve 1 is provided with a fixing groove 12 matched with the limit post 42, the limit post 42 is matched with the fixing groove 12, so that the position of the guide block 4 can be fixed, the guide block 4 can be conveniently and firmly installed, and the limit post 42 can be welded in the fixing groove 12 when in specific implementation. As shown in fig. 7, the sipe 11 is preferably a T-shaped sipe, i.e., a half open sipe, for facilitating the extension of the cutting edge 3.

As shown in fig. 6, the front end of the inner core 2 may be provided with an inclined sliding groove 22, and the cutting edge 3 is hinged in the sliding groove 22, so that the cutting edge 3 is conveniently hinged to the front end of the inner core 2. As shown in fig. 2 and fig. 6-7, the front portion of the inner core 2 may be provided with an axially extending limiting groove 23, a limiting hole 13 is provided on the connecting sleeve 1 at a position corresponding to the limiting groove 23, and a limiting pin 14 is disposed in the limiting groove 23 and the limiting hole 13 in a penetrating manner so as to limit the travel of the inner core 2 axially moving in the connecting sleeve 1, and further limit the length of the cutting edge 3 extending out of the cutter slot 11, so that excessive cutting can be avoided. The rear end of the inner core 2 can be a triangular structure 24, so that the power device can be conveniently connected.

The adjusting means for driving the inner core 2 to move axially in the connecting sleeve 1 (i.e. adjusting the relative positions of the connecting sleeve 1 and the inner core 2) can take various forms which can be easily conceived by a person skilled in the art, such as linear drawing, etc., however, for convenient implementation, the present utility model preferably adopts the following structural form:

As shown in fig. 1-2, the adjusting device may comprise a fixed block 5 located behind the connection sleeve 1, a rotating block 6 located behind the fixed block 5, and an adjusting knob 7 located on the rotating block 6, wherein:

the inner core 2 sequentially passes through the connecting sleeve 1, the fixed block 5 and the rotating block 6;

The rear end of the connecting sleeve 1 is fixedly arranged on the fixed block 5, the rotating block 6 is in driving connection with the inner core 2 and is axially fixed and circumferentially rotatably assembled on the fixed block 5, and the adjusting knob 7 can drive the inner core 2 to axially move in the connecting sleeve 1 through the rotating block 6.

At this time, the adjusting knob 7 is driven to drive the rotating block 6 to rotate relative to the fixed block 5, and the rotating block 6 drives the inner core 2 to axially move in the connecting sleeve 1, so that the cutting edge 3 at the front end of the inner core 2 is in abutting fit with the guide block 4, and the cutting edge 3 can rotate and extend out of the cutter slot 11.

The rotary block 6 is used to drive the inner core 2 axially in the connecting sleeve 1 in various ways, such as screw drive, which can be easily conceived by a person skilled in the art, however, for ease of implementation, the present utility model preferably adopts the following construction:

As shown in fig. 2, 6 and 9, a spiral groove 25 may be formed on a portion of the inner core 2 corresponding to the rotating block 6, a guide pin 61 is radially formed on an inner sidewall of the rotating block 6 at a position corresponding to the spiral groove 25 (in a specific implementation, a guide hole 62 may be formed on an inner sidewall of the rotating block 6, the guide pin 61 is fixedly disposed in the guide hole 62), and an end of the guide pin 61 extends into the spiral groove 25. At this time, the adjusting knob 7 is driven to drive the rotating block 6 to rotate relative to the fixed block 5, and the guide pin 61 slides in the spiral groove 25, so as to drive the inner core 2 to axially move in the connecting sleeve 1.

In order to realize the axially fixed and circumferentially rotatable assembly of the rotary block 6 on the fixed block 5, the utility model preferably adopts the following structural form:

as shown in fig. 1 and 8-9, on the opposite end surfaces of the fixed block 5 and the rotating block 6, one of them may be provided with a plug hole 63, the other one is provided with a plug section 51 matched with the plug hole 63, the plug section 51 is provided with an annular groove 52, a rotating hole 64 is provided on the side wall of the plug hole 63 at a position corresponding to the annular groove 52, a rotating pin 65 is provided in the rotating hole 64, and the end of the rotating pin 65 extends into the annular groove 52.

As shown in fig. 2 and fig. 10-11, in order to facilitate the implementation that the adjusting knob 7 drives the rotating block 6 to rotate relative to the fixed block 5, the adjusting knob 7 may be of a cylindrical structure sleeved on the rotating block 6, a plug mounting cavity (specifically, may be an inner hexagonal hole, and the plug 8 is a hexagonal shape at this time) 71 is disposed at the rear portion of the adjusting knob 7, a plug 8 that is circumferentially fixed and axially slidable (that is, the plug 8 may slide back and forth in the plug mounting cavity 71 and may not rotate in the plug mounting cavity 71) is disposed in the plug mounting cavity 71, and the plug 8 is fixedly disposed at the rear end of the rotating block 6, and at this time, the adjusting knob 7 is driven to drive the plug 8 to rotate, thereby driving the rotating block 6 to rotate relative to the fixed block 5. To achieve circumferentially fixed, axially slidable mounting of the plug 8 within the plug mounting cavity 71, the plug mounting cavity 71 and the plug 8 may be of a mating non-circular configuration (e.g., quadrilateral, pentagonal, hexagonal, etc.); the plug mounting cavity 71 and the plug 8 can also be of matched circular structures, and the plug mounting cavity can be matched with each other, and a limiting pin is added to realize circumferential limiting and axial sliding.

As further shown in fig. 2, 8 and 10-11, the adjusting device may be further provided with locking means for locking the relative positions of the adjusting knob 7 and the fixed block 5, wherein:

the front end of adjust knob 7 is equipped with the fixed block installation cavity 72 that is used for holding fixed block 5 rear end, and locking device is including being located the first spacing tooth (specifically can be straight tooth) 73 of fixed block installation cavity 72 inside wall to and be located fixed block 5 rear end surface and first spacing tooth 73 matched with second spacing tooth (specifically can be straight tooth) 53 to make things convenient for locking adjust knob 7 and fixed block 5 relative position, and then locking tool bit angle, make things convenient for the intraoperative use.

Thus, when the cutter head angle needs to be locked, the adjusting knob 7 is pushed forward, so that the first limiting teeth 73 on the inner side wall of the fixed block mounting cavity 72 are meshed with the second limiting teeth 53 on the outer surface of the rear end of the fixed block 5, and the cutter head angle can be locked; when the cutter head angle needs to be unlocked, the adjusting knob 7 is pushed backwards, so that the first limiting teeth 73 on the inner side wall of the fixed block mounting cavity 72 are separated from the second limiting teeth 53 on the outer surface of the rear end of the fixed block 5, and the cutter head can be unlocked.

Further, the front inner side wall of the adjusting knob 7 can be provided with an annular baffle 74, the rotating block 6 is sleeved with a spring 9, one end of the spring 9 abuts against the plug 8, the other end abuts against the annular baffle 74, and the spring 9 can provide supporting force to achieve a self-locking function, so that the device is more convenient to use in operation. When the angle of the cutter head needs to be unlocked, the adjusting knob 7 is pushed backwards, the spring 9 is compressed under the stress, and the first limiting teeth 73 are separated from the second limiting teeth 53, so that the cutter head can be unlocked; when the cutter head angle is required to be locked, the adjusting knob 7 is loosened, the spring 9 is relaxed, supporting force is provided, and the first limiting teeth 73 are meshed with the second limiting teeth 53, so that the cutter head angle can be locked again.

As shown in fig. 9 and 11, in order to fix the plug 8 at the rear end of the rotating block 6, a through hole 81 for accommodating the rear end of the rotating block 6 may be provided on the plug 8, one of the inner sidewall of the through hole 81 and the rear end side surface of the rotating block 6 is provided with a limiting table 82, and the other is provided with a limiting groove 66 matched with the limiting table 82. In the embodiment shown in the drawings, the stopper 8 is provided with a limiting table 82, and the rotating block 6 is provided with a limiting groove 66.

In order to better realize that the plug 8 is fixedly arranged at the rear end of the rotating block 6, the inner side wall of the through hole 81 and the side surface of the rear end of the rotating block 6 can be provided with mutually matched seam-riding threaded holes 83 and 67, and threaded jackscrews (not shown) are arranged in the seam-riding threaded holes 83 and 67. At this time, the stopper 82 of the plug 8 may be first installed in the stopper groove 66 of the rotary block 6, and then the stopper and the stopper may be fixed together by threaded jackscrews through the saddle thread holes 83 and 67. In the embodiment shown in the drawings, the number of the limiting tables 82 is two and is arranged oppositely, and the number of the riding thread holes 83 and 67 is also two and is arranged oppositely.

As shown in fig. 8, the fixed block 5 may be provided with a scale 55 corresponding to the diameter of the expanding drill reamer, so as to facilitate the adjustment of the diameter of the expanding drill reamer during operation and facilitate the use during operation. The front part of the fixed block 5 can be provided with a stepped hole 54, and the connecting sleeve 1 is inserted and fixed in the stepped hole 54, so that the connecting sleeve 1 is conveniently and fixedly connected with the fixed block 5, and the fixed block 5 can be welded into a whole at the stepped hole 54 during specific implementation.

In summary, the use process of the adjustable expansion drill of the present utility model can be referred to as follows:

firstly anaesthetizing, cutting skin, exposing a drilling position, drilling a hole by using a drill bit to a reaming depth, connecting a triangular structure 24 at the rear end of an inner core 2 of the adjustable expansion drill of the utility model with a power device, inserting the triangular structure into the bottom position of the drilled hole, then adjusting an adjusting knob 7 according to the reaming diameter requirement and according to a mark of a scale 55 so as to adjust the angle of a cutter head of the adjustable expansion drill, locking after the angle of the cutter head is adjusted, finally driving the power device to slowly drill, and finishing the reaming depth according to the requirement.

While the foregoing is directed to the preferred embodiments of the present utility model, it will be appreciated by those skilled in the art that various modifications and adaptations can be made without departing from the principles of the present utility model, and such modifications and adaptations are intended to be comprehended within the scope of the present utility model.

Claims (10)

1. An adjustable expansion drill, characterized by, including the adapter sleeve that the head end is sealed and lie in the adapter sleeve and with adapter sleeve sliding connection's inner core, wherein:

The front end of the inner core is hinged with a cutting edge in the connecting sleeve, a guide block for guiding the cutting edge is arranged on the inner side of the front end of the connecting sleeve, and a cutter groove for the cutting edge to extend out is formed in the side face of the front part of the connecting sleeve;

The rear part of the adjustable expansion drill is provided with an adjusting device, and the adjusting device can drive the inner core to axially move in the connecting sleeve so that the cutting edge is in abutting fit with the guide block, and the cutting edge can rotate and extend out of the cutter groove.

2. The adjustable expansion drill according to claim 1, wherein one of the opposing end surfaces of the guide block and cutting edge is provided with an arcuate guide slot, and the other is provided with an arcuate guide table cooperating with the arcuate guide slot, wherein:

the arc-shaped guide groove and the arc-shaped guide table are both T-shaped;

And/or the side surface of the front end of the guide block is provided with a radially extending limit column, and the front end of the connecting sleeve is provided with a fixing groove matched with the limit column;

And/or the knife groove is a T-shaped groove.

3. The adjustable expansion drill according to claim 1, wherein the front end of the inner core is provided with an oblique sliding groove, and the cutting edge is hinged in the sliding groove;

And/or the front part of the inner core is provided with an axially extending limit groove, a limit hole is arranged at a position on the connecting sleeve corresponding to the limit groove, and limit pins are arranged in the limit groove and the limit hole in a penetrating manner;

And/or the rear end of the inner core is in a triangular structure.

4. An adjustable expansion drill according to any one of claims 1-3, wherein the adjustment means comprises a fixed block behind the connection sleeve, a rotating block behind the fixed block, and an adjustment knob on the rotating block, wherein:

The inner core sequentially passes through the connecting sleeve, the fixed block and the rotating block;

The rear end of the connecting sleeve is fixedly arranged on the fixed block, the rotating block is in driving connection with the inner core, the inner core is axially fixed and circumferentially rotatable and assembled on the fixed block, and the adjusting knob can drive the inner core to axially move in the connecting sleeve through the rotating block.

5. The adjustable expansion drill according to claim 4, wherein a spiral groove is formed in a portion of the inner core corresponding to the rotary block, a guide pin is radially arranged on the inner side wall of the rotary block at a position corresponding to the spiral groove, and the tail end of the guide pin extends into the spiral groove;

And/or, the opposite end surfaces of the fixed block and the rotating block are provided with a plug hole, one of the end surfaces is provided with a plug section matched with the plug hole, the plug section is provided with an annular groove, the side wall of the plug hole is provided with a rotating hole at a position corresponding to the annular groove, the rotating hole is internally provided with a rotating pin, and the tail end of the rotating pin extends into the annular groove.

6. The adjustable expansion drill according to claim 4, wherein the adjusting knob is of a cylindrical structure sleeved on the rotating block, a plug mounting cavity is formed in the rear portion of the adjusting knob, a circumferentially fixed and axially slidable plug is arranged in the plug mounting cavity, and the plug is fixedly arranged at the rear end of the rotating block.

7. The adjustable expansion drill according to claim 6, wherein the adjusting device is further provided with a locking device for locking the relative positions of the adjusting knob and the fixed block, wherein:

the front end of the adjusting knob is provided with a fixed block installation cavity for accommodating the rear end of the fixed block, and the locking device comprises a first limiting tooth positioned on the inner side wall of the fixed block installation cavity and a second limiting tooth positioned on the outer surface of the rear end of the fixed block and matched with the first limiting tooth.

8. The adjustable expansion drill according to claim 7, wherein an annular baffle is arranged on the inner side wall of the front portion of the adjusting knob, a spring is sleeved on the rotating block, one end of the spring abuts against the plug, and the other end of the spring abuts against the annular baffle.

9. The adjustable expansion drill according to claim 6, wherein the plug is provided with a through hole for receiving a rear end of the rotary block, wherein:

The inner side wall of the through hole and the side surface of the rear end of the rotating block are provided with a limiting table, and one of the two is provided with a limiting groove matched with the limiting table;

And/or, the inner side wall of the through hole and the side surface of the rear end of the rotating block are respectively provided with a mutually matched seam-riding threaded hole, and a threaded jackscrew is arranged in the seam-riding threaded hole.

10. The adjustable expansion drill according to claim 4, wherein the fixed block is provided with graduations corresponding to the diameter of the expansion drill;

And/or the front part of the fixed block is provided with a stepped hole, and the connecting sleeve is inserted and fixed in the stepped hole.