Micropore grinding drill with telescopic tool bit

Abstract

The invention relates to a micropore abrasive drill with a telescopic tool bit, and belongs to the technical field of orthopedic instruments. The insertion part extends out from the far end of the holding part, and an accommodating channel is formed in the insertion part; the rotating shaft is coaxially arranged in the insertion part, and a tool bit is arranged at the far end of the rotating shaft; the insertion part adjusting device is movably installed on the holding part and used for driving the rotating shaft to move in the axial direction relative to the insertion part and adjusting the length of the part, stretching out of the far end of the insertion part, of the tool bit. Depth control is changed from manual whole machine feeding control to precise mechanism adjusting local feeding control, the grinding depth can be precisely controlled according to individual differences of patients, and the problem that the effect is affected by too shallow hole sites or the inferior bone structure is damaged due to too deep hole sites is effectively solved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of orthopedic instruments, and particularly relates to a telescopic micro-hole drill bit. BACKGROUND

[0002] In orthopedic clinical treatment, microfracture is a common cartilage repair method, and the basic principle thereof is to induce bone marrow-derived stem cells to exude by drilling or punching holes on the bone surface of the cartilage defect area, so as to promote the repair of cartilage and ligament. The existing clinical means usually uses a drill bit, awl or impactor with a fixed depth to complete the preparation of the micro-hole on the bone surface.

[0003] The commonly used microfracture impactor or drill bit has a fixed drilling depth, and it is difficult for a doctor to accurately control the depth of the micro-hole during the operation process, which may easily lead to too shallow holes affecting the repair effect or too deep holes damaging the bone structure and increasing the risk of postoperative complications.

[0004] Therefore, the present disclosure provides a telescopic micro-hole drill bit with a telescopic drill bit, which can controllably adjust the drilling depth and form a stable micro-hole structure on the bone surface. SUMMARY

[0005] The purpose of the present application is to provide a telescopic micro-hole drill bit to solve the problems of unadjustable drill bit depth and low safety.

[0006] To solve the above technical problems, the present application is realized by the following technical scheme:

[0007] A telescopic micro-hole drill bit, comprising:

[0008] a holding part for holding operation;

[0009] an insertion part extending from the distal end of the holding part and having an accommodation channel formed inside;

[0010] a rotating shaft coaxially arranged in the insertion part, and having a drill bit at the distal end thereof;

[0011] an insertion part adjusting device movably mounted on the holding part and linked with the rotating shaft, for driving the rotating shaft to axially displace relative to the insertion part, so as to adjust the length of the drill bit extending out of the distal end of the insertion part.

[0012] Further, the insertion part comprises, from outside to inside:

[0013] an outer tube having a drill bit seat at the distal end thereof, and the drill bit seat is provided with a through hole for the distal end of the rotating shaft to pass through;

[0014] an inner support tube arranged between the outer tube and the rotating shaft, for radially limiting the rotating shaft;

[0015] The distal end of the rotating shaft is provided with a small diameter section, the cutter head is fixed on the small diameter section, and the diameter of the through hole of the cutter head seat matches the small diameter section and is smaller than the outer diameter of the rotating shaft body.

[0016] Furthermore, the inner support tube includes a self-lubricating hose and a supporting copper sleeve, and the self-lubricating hose and the supporting copper sleeve are arranged alternately along the axis of the rotating shaft.

[0017] Furthermore, the self-lubricating hose is made of polyetheretherketone material, and its outer surface is provided with a plurality of fixed blades with an elastic curved surface structure, the fixed blades being interference fit with the inner wall of the outer tube.

[0018] Furthermore, the gripping part is provided with a mounting groove inside, and the mounting groove is provided with:

[0019] A modular sleeve, which is fixedly connected to the insertion adjustment device;

[0020] The buffer assembly is disposed in the mounting through hole of the module sleeve, and from the far end to the near end includes a friction copper sleeve, a shock-absorbing rubber ring and a rotating bearing in sequence.

[0021] The rotating shaft is fixedly connected to the connecting sleeve, which is installed inside the rotating bearing.

[0022] Furthermore, the distal end of the module sleeve abuts against the distal positioning block via a first spring, and the proximal end of the module sleeve abuts against the fixed sleeve via a second spring.

[0023] Furthermore, the proximal end of the connecting sleeve is provided with a motor fork, the motor fork is provided with an axially extending mounting groove, and the connecting sleeve is movably installed in the mounting groove by a fixing pin.

[0024] Furthermore, the supporting copper sleeve has a notch and an oblong cross-section.

[0025] Furthermore, the distal end of the insertion portion is provided with a curved section;

[0026] The rotating shaft has a shaft bending section at the position corresponding to the bending section.

[0027] Furthermore, the bent section of the shaft and the straight section of the rotating shaft are made of an integrated hollow metal tube, and the tube wall is divided into multiple interconnected connecting strips by setting multiple cutting grooves along the axial direction;

[0028] A flexible support shaft is inserted within the bent section of the shaft, and its outer surface is covered with a heat-shrink tubing. Beneficial effects:

[0029] 1. This invention, by incorporating an insertion adjustment device, enables controllable axial relative displacement between the rotating shaft and the outer tube. This allows for adjustment of the cutter head's extension amount according to actual needs, thereby achieving precise control of drilling depth. This structure effectively avoids the problems of drilling too deep or too shallow that exist with existing fixed-depth drills, improving the consistency and safety of drilling during microfracture surgery.

[0030] 2. The insertion part of this invention adopts a double-layer structure of an outer tube and an inner support tube. The inner support tube is composed of alternating self-lubricating hoses and support copper sleeves. This structure can provide sufficient support for the high-speed rotating shaft and effectively reduce vibration and sway during rotation, thereby improving the stability and reliability of the drill during high-speed operation.

[0031] 3. The moving module sleeve is equipped with components such as friction copper sleeves, shock-absorbing rubber rings, and rotating bearings, forming a stable buffer and vibration reduction system that can effectively absorb motor vibration and axial impact, reducing operating noise and vibration. The groove-fixed pin structure between the motor fork and the coupling sleeve ensures reliable torque transmission while retaining necessary axial movement space, further improving structural durability.

[0032] 4. Both the distal end of the insertion section and the distal end of the rotating shaft are equipped with flexible sections. These flexible sections form a flexible connection structure through cutting grooves along the axis, and are internally equipped with a supporting flexible shaft and an outer heat-shrinkable sleeve. This allows for stable torque transmission while achieving bending guidance. This structure enables the drill to operate flexibly in complex surgical areas such as joint cavities or curved bone areas, expanding its applicability.

[0033] Of course, any product implementing this invention does not necessarily need to achieve all of the advantages described above at the same time. Attached Figure Description

[0034] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 This is an overall structural diagram of an embodiment of the present disclosure;

[0036] Figure 2 This is a diagram showing the internal structure of the gripping part according to an embodiment of this disclosure;

[0037] Figure 3 This is a cross-sectional view of the gripping portion according to an embodiment of the present disclosure;

[0038] Figure 4 This is an exploded view of the insertion part according to an embodiment of the present disclosure;

[0039] Figure 5 This is an exploded view of the bent insertion portion of an embodiment of this disclosure;

[0040] Figure 6 This is a structural diagram of the internal support tube in an embodiment of this disclosure;

[0041] Figure 7 This is a diagram showing the internal structure of the bent section of the insertion part in this embodiment.

[0042] Figure 8 This is a structural diagram of the flexible shaft portion of the present disclosure. Detailed Implementation

[0043] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0044] like Figures 1-4 As shown, this embodiment discloses a retractable micro-hole drill, which mainly consists of a gripping part 1, an insertion part 2, a rotating shaft 3, and an insertion part adjustment device 4:

[0045] The gripping part 1 serves as the control end of the instrument, allowing medical staff to hold it and perform various operations.

[0046] The insertion part 2 has a long tubular structure that extends from the distal end of the gripping part 1 and forms a channel inside to accommodate the rotating shaft 3.

[0047] The rotating shaft 3 is coaxially disposed in the insertion part 2, and its distal end is provided with a cutting head 31 for performing deboning operations;

[0048] The insertion adjustment device 4 is movably mounted on the gripping part 1 and is used to drive the rotating shaft 3 to move axially relative to the insertion part 2, thereby precisely adjusting the extension length of the cutter head 31.

[0049] like Figure 4 As shown, in order to balance rigid support during surgery and stability under high-speed rotation, the insertion part 2 adopts a composite layered design from the outside to the inside.

[0050] The outer tube 21, made of metal, is fixed at its proximal end to the gripping part 1, providing necessary rigid support and positioning for the whole. The distal end of the outer tube 21 is fixed to the cutter head seat 24 by welding or other means.

[0051] The cutter head holder 24 has a through hole inside for the distal end of the rotating shaft to pass through, providing guidance when the cutter head 31 retracts or extends, and serving as distal end protection when the cutter head 31 rotates.

[0052] The inner support tube 22 is set between the outer tube 21 and the rotating shaft 3. By radially limiting the rotating shaft 3, it ensures that the rotating shaft 3 does not wobble violently during high-speed rotation, thereby improving operational stability.

[0053] This design achieves precise control of the drilling depth by adjusting the axial relative displacement between the rotating shaft 3 and the insertion part 2. The specific steps are as follows;

[0054] In the non-operating state, the blade 31 is completely retracted into the blade holder 24 and is not exposed. This state protects the blade 31 and effectively avoids accidental mechanical damage to surrounding soft tissues or bone surfaces when entering the surgical path.

[0055] Depth adjustment state: After the instrument reaches the target area, the operator adjusts the insertion adjustment device 4, driving the rotating shaft 3 to move axially to the distal end. At this time, the blade 31 gradually extends out of the blade holder 24, and the extension amount can be precisely adjusted according to the specific clinical needs for the depth of the micropore.

[0056] The power unit is activated; the rotating shaft 3 drives the drill head 31 to rotate at high speed to perform drilling operations. Since the extension length of the drill head 31 is pre-locked, it can form microholes with constant depth and stable structure, effectively reducing the risk of repair failure due to being too shallow or bone damage due to being too deep.

[0057] After drilling is completed, the cutting head 31 is reset back into the cutting head seat 24 using the adjustment device, and the power source is turned off to ensure that the instrument can be safely removed from the surgical area.

[0058] In this embodiment, the present invention also provides a precise drilling mode based on a bone surface reference plane:

[0059] First, with the blade 31 in the retracted state, the medical staff directly presses the distal end of the outer tube 21 against the bone surface to be treated. Because the end face of the blade holder 24 is a flat structure, it can form a stable support plane and a zero point of depth after contacting the bone surface.

[0060] While maintaining the constant contact force between the outer tube 21 and the bone surface, the rotating shaft 3 is driven to extend axially distally relative to the outer tube 21 by operating the insertion adjustment device 4 on the gripping part 1. At this time, the cutting head 31 extends out from the cutting head seat 24 and cuts into the bone tissue.

[0061] The actual drilling depth depends entirely on the axial extension of the rotating shaft 3 relative to the outer tube 21. This eliminates uneven force or depth errors caused by manually pushing the entire device, ensuring a high degree of consistency between the micro-hole depth and the preset adjustment amount.

[0062] like Figure 4 , Figure 5As shown, the distal end of the rotating shaft 3 has a small-diameter section 32, on which the cutting head 31 is fixedly mounted. The through hole 241 on the cutting head holder 24 matches the diameter of the small-diameter section 32, but its diameter is smaller than the outer diameter of the main body of the rotating shaft 3. Through this stepped matching design, when the rotating shaft 3 extends forward to its limit position, the shoulder of the main body of the rotating shaft 3 will abut against the cutting head holder 24, thereby effectively avoiding tissue damage caused by excessive extension.

[0063] like Figure 6 As shown, the inner support tube 22 adopts a design of alternating heterogeneous materials to ensure the stability of the rotating shaft 3 under high-speed rotation:

[0064] The inner support tube 22 is composed of a self-lubricating hose 221 and a support copper sleeve, which are alternately combined in sequence. The rotating shaft 3 is fitted with the inner hole of the self-lubricating hose 221 and the support copper sleeve with a clearance fit.

[0065] The self-lubricating hose 221 is made of polyetheretherketone (PEEK) material. This alternating structure can provide high-rigidity radial support for the shaft 3, and can effectively reduce vibration and noise generated by high-speed rotation by utilizing the self-lubricating properties and elastic modulus of PEEK material.

[0066] To ensure axial stability, a snap-fit ​​structure is used between the self-lubricating hose 221 and the copper sleeve. Specifically, the intermediate copper sleeve 223 and the two end copper sleeves 222 are respectively provided with a first positioning groove 2221 and a second positioning groove 2231 on the side facing the self-lubricating hose 221. Correspondingly, the two ends of the self-lubricating hose 221 are provided with a first positioning step 2211 that cooperates with the above positioning grooves.

[0067] In addition, the outer surface of the self-lubricating hose 221 is provided with uniformly distributed fixing blades 2212. These fixing blades 2212 are designed with an elastic curved surface structure, and their outer diameter is slightly larger than the inner diameter of the outer tube 21, thereby forming an interference fit with the inside of the outer tube 21. During the assembly process, the radial contact between the fixing blades 2212 and the inner wall achieves stable anchoring of the inner support tube 22 within the outer tube 21.

[0068] In some disclosures, the copper sleeve has notches on both sides, and the interface of the copper sleeve is waist-shaped. The notches form a liquid channel with the outer tube, so that cooling liquid can be introduced from the gripping part. The liquid enters from the end of the outer tube 21, moves to the distal end through the gap between the fixed blades 2212 and the notches on both sides of the copper sleeve, and finally flows out from the distal end of the insertion part. In this way, the cutter head 31 is lubricated and cooled by the liquid. At the same time, in the water medium, the thermal damage inside the rotating hole can be prevented and the recovery speed can be improved.

[0069] The system employs an alternating support structure combining soft and hard elements. The self-lubricating properties of PEEK material reduce frictional resistance during high-speed rotation of the shaft, while the rigidity of the copper sleeve provides stable support. The elastic design of the fixed blades not only simplifies the assembly process but also effectively absorbs radial vibrations generated by the shaft, reducing noise and vibration of the surgical instruments.

[0070] like Figure 2 , Figure 3 As shown, the gripping part 1 has a mounting groove 10 inside for integrating the drive component:

[0071] The module sleeve 11 is installed in the mounting groove 10, and its interior has an axially extending mounting through hole 111. The insertion adjustment device 4 is movably installed in the sliding groove on the surface of the grip part 1, and its bottom end passes through the mounting groove 10 through a structural connection and is fixedly connected to the module sleeve 11 inside. The connection structure can be such as a pin or a slot.

[0072] The mounting through hole 111 contains, from far to near, a friction copper sleeve 1111, a shock-absorbing rubber ring 1112, and a rotating bearing 1113. The shock absorption system formed by the combination of multiple materials can effectively absorb the high-frequency vibration and axial impact generated by the motor, improve the smoothness of operation, and reduce noise.

[0073] The rotating shaft 3 is driven by the connecting sleeve 17. The rotating shaft 3 is fixedly connected to the connecting sleeve. The connecting sleeve 17 passes through the mounting through hole 111 and is fixedly installed in the rotating bearing 1113. The connecting sleeve 17 and the rotating shaft 3 are fixedly connected.

[0074] In this embodiment, the drilling depth is precisely adjusted by the overall displacement of the module sleeve 11, as detailed below;

[0075] The insertion adjustment device 4 is linked with the module sleeve 11, driving the module sleeve 11 to move along the axial direction in the mounting groove 10, thereby driving the rotating shaft 3 to feed or retract synchronously.

[0076] The module sleeve 11 has a distal positioning block 13 at its distal end, and a first spring 14 is provided between the two.

[0077] A fixed sleeve 12 is provided at the near end of the module sleeve 11, and a second spring 15 is provided between the two.

[0078] This design, through the combined action of the first spring 14 and the second spring 15, allows the module sleeve 11 to maintain a preset equilibrium position when no external force is applied. When the operator applies external force, the module sleeve 11 overcomes the elastic pressure of the springs to change position, thus achieving the control effect.

[0079] In some disclosures, to facilitate the maintenance of the device and the power connection, the outer side of the motor insertion part and the inside of the fixed sleeve 12 are detachably and securely connected by friction.

[0080] like Figure 3 As shown, a spring washer 16 is also provided on the near end face of the rotating bearing 1113 to abut against the second spring 15. This washer not only provides support but also effectively prevents the spring from directly contacting the bearing and generating metal debris, thus preventing debris from entering the bearing and affecting its rotational accuracy and service life.

[0081] The near end of the connecting sleeve 17 is provided with a motor front fork 18, on which an axially extending mounting groove 181 is provided. A fixing pin 171 is transversely inserted through the connecting sleeve 17. The fixing pin 171 passes through the through hole near the shaft 3 to complete the drive connection between the shaft 3 and the connecting sleeve 17. The two ends of the fixing pin 171 extend into the mounting groove 181 respectively.

[0082] The engagement of the fixing pin 171 and the mounting groove 181 ensures that the motor fork 18 can reliably transmit rotational torque to the connecting sleeve 17. At the same time, since the fixing pin 171 can slide axially within the mounting groove 181, the motor fork 18 has sufficient axial movement space when the rotating shaft 3 moves with the module sleeve 11 for depth adjustment.

[0083] In some preferred embodiments, a spring may be added between the motor fork 18 and the connecting sleeve 17 to enhance the axial fastening effect between the fork and the motor.

[0084] In some implementations, such as Figure 5 , Figure 7 , Figure 8 As shown, in order to adapt to the operational requirements of complex surgical spaces such as joint cavities, the distal end of the insertion part 2 in this embodiment is designed as a curved section 2a:

[0085] The outer tube 21 has a prefabricated curved section 212 with a specific curvature at its far end, which provides rigid guidance for the internal components.

[0086] The distal end of the inner support tube 22 is provided with a self-lubricating flexible hose 23.

[0087] The rotating shaft 3 includes a rigid section 34, the distal end of which is provided with a shaft bending section 33 that matches the bending section 2a of the insertion part.

[0088] In this embodiment, the specific steps for performing microfracture procedures in complex anatomical spaces such as joint cavities or curved bone areas are as follows:

[0089] Using a pre-fabricated curved segment 212 at the distal end of the outer tube as a rigid guide, the instrument enters the surgical area via a minimally invasive approach. The specific curvature of the curved segment 212 allows the instrument to bypass obstacles and precisely reach the target bone surface along a non-linear path.

[0090] Adjust the cutter head 31 to the retracted position, and place the distal end of the outer tube 21 or the end face of the cutter head seat 24 against the curved bone surface to establish a stable depth starting zero point.

[0091] The power source is activated simultaneously by adjusting the device, driving the rotating shaft 3 to extend axially. At this time, the shaft bending section 33 of the rotating shaft 3 undergoes flexible deformation along the preset arc of the outer tube 212 under the radial limitation of the self-lubricating bending hose 23 and the bending spiral tube 231, ensuring that the cutter head 31 always moves along the preset axial trajectory.

[0092] The rotating shaft 3 drives the cutter head 31 to rotate. The bent section 33 of the shaft maintains constant torque transmission in the bent state through the cutting groove 3321 on it and the internal plastic support flexible shaft 331, thus completing the micro-hole drilling.

[0093] After the operation is completed, the slider retracts the blade 31 into the blade holder 24 and removes it from the surgical area along with the entire instrument.

[0094] This design, through the coordinated operation of the curved section 212 at the distal end of the outer tube and the curved section 33 of the rotating shaft, solves the technical problem that existing straight shank drills cannot reach hidden locations in the joint cavity or curved bone surfaces.

[0095] Furthermore, a curved spiral tube 231 is sleeved on the outside of the self-lubricating curved hose 23. The combination of the self-lubricating material and the spiral tube can reduce the friction of the shaft 3 in the bent state and provide sufficient radial support force.

[0096] like Figure 8 As shown, the bending section 33 of the shaft and the straight section of the rotating shaft 3 are made of an integrated hollow metal tube. By setting multiple cutting grooves 3321 along the axial direction, the tube wall is divided into multiple interconnected connecting strips 332, which enables the metal tube to have a certain bending capability.

[0097] To prevent the bent section 33 from becoming unstable or twisted when transmitting high-speed torque, a flexible plastic support shaft 331 is inserted inside its tube.

[0098] A heat shrink tubing 333 is tightly fitted onto the outer side of the bent section 33 of the shaft. The heat shrink tubing not only seals the cutting gap and prevents debris from entering, but also reduces the frictional resistance between it and the inner support tube when the shaft rotates at high speed.

[0099] It is understandable that the shaft bending section 33 can be made of nickel-titanium alloy, and can be integrated with the rotating shaft 3 or separately set by welding. Of course, the shaft bending section 33 can also be a braided flexible shaft that is pressed together with the rigid part of the rotating shaft 3.

[0100] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0101] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A retractable micro-bore drill bit, characterized in that, The utility model relates to a kind of surgical knife, including: Grip, for holding operation; Insertion part, from the distal end of the grip extends out, inside forms accommodating channel; Rotary shaft, coaxially arranged in the insertion part, its distal end is equipped with tool bit; Insertion part adjusting device, movably mounted on the grip, and with the rotary shaft linkage, for driving the rotary shaft relative to the insertion part in axial displacement, adjust the length of the tool bit protruding from the distal end of the insertion part.

2. The retracting micro-bore drill bit according to claim 1, wherein, The insertion part includes from outside to inside: Outer tube, its distal end is equipped with tool bit seat, the tool bit seat is equipped with the through-hole for the distal end of the rotary shaft to go out; Inner support tube, arranged between the outer tube and the rotary shaft, for the rotary shaft is radially limited; The distal end of the rotary shaft is equipped with small diameter section, the tool bit is fixed on the small diameter section, and the diameter of the through-hole of the tool bit seat matches the small diameter section and is smaller than the outer diameter of the rotary shaft body.

3. The retracting micro-boring drill bit according to claim 2, wherein, The inner support tube includes self-lubricating hose and support copper sleeve, the self-lubricating hose and the support copper sleeve are arranged alternately along the axial direction of the rotary shaft.

4. The retracting micro-boring drill bit according to claim 3, wherein, The self-lubricating hose is made of polyether ether ketone material, and a plurality of elastic curved surface structure fixing blades are arranged on the outer surface of the self-lubricating hose, the fixing blades are in interference fit with the inner wall of the outer tube.

5. The retracting micro-boring drill bit according to claim 1, wherein, The inside of the grip is provided with a mounting groove, and the mounting groove is provided with: Module sleeve, the module sleeve is fixedly connected with the insertion part adjusting device; Buffer assembly, arranged in the mounting through-hole of the module sleeve, sequentially including friction copper sleeve, shock-absorbing rubber ring and rotating bearing from distal end to proximal end; The rotary shaft is fixedly connected with the connecting sleeve, and the connecting sleeve is installed in the rotating bearing.

6. The retracting micro-boring drill bit according to claim 5, wherein, The distal end of the module sleeve is abutted by the distal end positioning block through the first spring, and the proximal end of the module sleeve is abutted by the fixed sleeve through the second spring.

7. The retracting micro-boring drill bit according to claim 5, wherein, The proximal end of the connecting sleeve is provided with a motor fork, and the motor fork is provided with an axially extending mounting sliding groove, and the connecting sleeve is movably installed in the mounting sliding groove through a fixed pin.

8. The retracting micro-boring drill bit according to claim 5, wherein, The support copper sleeve is provided with a notch and a waist-shaped cross section.

9. The retracting micro-boring drill bit according to claim 1, wherein, The distal end of the insertion part is provided with a curved section; The rotary shaft is provided with an axial curved section at the position corresponding to the curved section.

10. The retracting micro-boring drill bit according to claim 9, wherein, The axial curved section and the straight section of the rotary shaft are made of an integrated hollow metal pipe, and the pipe wall is divided into a plurality of connected strips by arranging a plurality of cutting grooves along the axial direction. A bendable support flexible shaft is arranged in the axial curved section, and a heat-shrinkable sleeve is coated on the outer surface.

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