Limiting counter bore device

Abstract

The utility model discloses a limiting counter bore device which comprises a drill body, a limiting piece, a tool bit body capable of axially sliding in a center channel, a center drill capable of axially sliding in the installation channel of the tool bit body, a matched locking assembly and a fine adjustment assembly. Through split arrangement of the counter bore tool bit and the center drill and the fine adjustment assembly, the distance from the bottom of the center hole to the counter bore can be adjusted, the depth of the counter bore can be accurately adjusted in a stepless mode, and cost is reduced. And the locking assembly guarantees the machining stability, and the application range can be expanded by switching the counter bore tool bit. The limiting counter bore device is reasonable in design, integrates operation convenience, machining adaptability and economical efficiency, and is high in practical value.

Description

Technical Field

[0001] This utility model relates to the field of drill bit technology, and in particular to a limiting countersinking device. Background Technology

[0002] A countersinking tool, also known as a countersinking drill, is a commonly used drill bit in woodworking. It is mainly used to drill center holes and countersinks of a certain depth in wood for the installation of screws or mortise and tenon joints. The purpose of the countersink is to ensure that the top of the screw does not protrude from the wood surface, thus ensuring the aesthetics of the woodworking. Existing countersinking tools mainly consist of a drill body, a center drill, and a shank for connecting to an external drive device. The center drill has an integrally formed countersinking cutter head, which is installed in the drill body with a fastening screw during installation.

[0003] However, in existing countersinkers, the integrated structure of the countersink cutter and the center drill makes it impossible to adjust the distance between the countersink and the bottom of the center hole. In some working environments, when it is necessary to process holes with the same countersink depth but different center hole depths, it is necessary to replace both the center drill and the countersink cutter. This replacement is very troublesome and cumbersome. At the same time, it is also necessary to prepare many center drills of different specifications, which greatly increases the production cost of the equipment and also makes it inconvenient to carry. Utility Model Content

[0004] The main purpose of this utility model is to provide a limiting countersinker, which aims to adjust the distance between the bottom of the center hole and the countersink by separating the countersinking cutter head and the center drill, and with the help of a fine-tuning component. At the same time, it can make the countersinking depth infinitely precise, making the limiting countersinker more convenient to adjust during use and reducing production costs.

[0005] To achieve the above objectives, this utility model proposes a limiting countersinking device, comprising a drill body and a limiting component. The drill body has a central channel with an installation opening at one end, and also includes...

[0006] The cutter head body is disposed within the central channel and can slide along the axial direction of the central channel; the cutter head body is provided with an installation channel;

[0007] A center drill is installed within the installation channel and can slide along the axial direction of the installation channel.

[0008] A locking component is used to lock the positions of the cutter head body, the drill body, and the center drill and the cutter head body.

[0009] The fine-tuning component is used to drive the cutter head body to move axially along the central channel toward the mounting port to adjust the relative position between the cutter head body and the limiting member when the locking component releases the lock between the cutter head body and the drill body.

[0010] In one possible implementation, the locking assembly includes a first fixing hole disposed on one side of the cutter head body and a second fixing hole disposed on one side of the drill body, the first fixing hole communicating with the mounting channel and the second fixing hole communicating with the central channel; it also includes fastening screws threadedly connected to the first fixing hole and the second fixing hole, and a pair of fastening screws respectively engaging with the central drill and one side of the cutter head body.

[0011] In one possible implementation, the fine-tuning component includes an adjustment channel disposed within the drill body and communicating with the central channel, the adjustment channel being coaxially arranged with the central channel and located at the end of the central channel away from the mounting port; it also includes a pin threadedly connected to the adjustment channel, one end of the pin being an abutment portion for driving the cutter head body, and the other end being a driving portion for driving the pin to rotate.

[0012] In one possible implementation, the driving part is a groove provided on the end face of the pin, and the drill body is provided with an operating channel that is coaxial with and communicates with the adjustment channel. The operating channel corresponds to the position of the groove, and the operator can extend an external tool into the adjustment channel through the operating channel to control the rotation of the pin.

[0013] In one possible implementation, the cutter head body includes an extension, the end of which is provided with a countersunk hole with a cutting edge.

[0014] In one possible implementation, the mounting channel extends through the cutter head body, and two countersunk holes are provided, respectively located at both ends of the extension, with the two countersunk holes producing different diameters.

[0015] In one possible implementation, the end of the drill body away from the center drill is also provided with a shank, which is integrally formed with the drill body or assembled separately.

[0016] In one possible implementation, when the shank and the drill body are assembled separately, one end of the shank is inserted into the operating channel, and a screwdriver head is provided at the end inserted into the operating channel.

[0017] In one possible implementation, when the shank and the drill body are integrally formed, the operating channel is provided through the shank.

[0018] In one possible implementation, the shank and the operating channel are detachably connected via a quick-connect structure. The quick-connect structure includes an assembly hole on the periphery of the drill body's tail and an annular groove on one end of the shank corresponding to the assembly hole. The assembly hole is perpendicular to and communicates with the operating channel, and a ball bearing is rolled within the assembly hole. It also includes a connecting bushing fitted onto the drill body, with a return spring between the connecting bushing and the drill body, and a drive ring on the inner side of the connecting bushing. When the drive ring of the connecting bushing compresses the return spring, a gap is created between the inner wall of the connecting bushing and the assembly hole, allowing the ball bearing to move outward and releasing the engagement between the shank and the operating channel. When the return spring drives the connecting bushing to return and slide, the drive ring within the connecting bushing compresses the ball bearing to move inward, thus engaging the insertion hole with the shank.

[0019] In summary, the beneficial effects of this application are as follows:

[0020] Compared with existing technologies, this utility model features a separate countersinking cutter head and center drill, supplemented by a fine-tuning component that allows for precise axial adjustment. This enables flexible adjustment of the distance between the bottom of the center hole and the countersinking hole according to actual processing requirements, effectively avoiding the inconvenience of replacement caused by the one-piece molding of traditional structures. This significantly improves the flexibility and adaptability during use. Furthermore, the fine-tuning component allows for stepless precise adjustment of the countersinking depth, ensuring processing accuracy without the need for frequent replacements of center drills of different specifications, thus reducing overall usage and manufacturing costs. The locking component ensures reliable positioning between the cutter head, drill body, and center drill, guaranteeing stability and safety during processing. The switchable countersinking cutter head structure not only further expands the tool's applicability but also reduces the burden of carrying and replacing tools. The overall structural design is reasonable, balancing ease of operation, processing adaptability, and economy, significantly enhancing the practical value of the countersinking tool. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0022] Figure 1 This is a three-dimensional structural diagram of Embodiment 1 of this application;

[0023] Figure 2 This is an exploded structural diagram of Embodiment 1 of this application;

[0024] Figure 3This is a cross-sectional structural diagram of Embodiment 1 of this application;

[0025] Figure 4 This is a three-dimensional structural diagram of the cutter head body of this application;

[0026] Figure 5 This is a three-dimensional structural diagram of Embodiment 2 of this application;

[0027] Figure 6 This is a cross-sectional structural diagram of Embodiment 2 of this application;

[0028] Figure 7 This is a schematic diagram of the structure of Embodiment 3 of this application.

[0029] Explanation of icon numbers:

[0030] 1. Drill body; 11. Center channel; 2. Limiting component; 3. Cutter head body; 31. Mounting channel; 32. Extension; 33. Countersunk section; 4. Center drill; 5. Locking assembly; 51. First fixing hole; 52. Second fixing hole; 53. Fastening screw; 6. Fine-tuning assembly; 61. Adjustment channel; 62. Pin; 63. Operating channel; 7. Shank; 8. Quick-connect structure; 81. Ring groove; 82. Assembly hole; 83. Ball bearing; 84. Connecting bushing; 85. Drive ring; 86. Return spring; 9. Connecting rod; 10. Clamping surface; 101. Chamfering and trimming cutter head; 12. Limiting plate.

[0031] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0033] Example 1

[0034] like Figure 1-4 As shown, this utility model proposes a limiting countersunk hole device, such as... Figure 1-2As shown, the system includes a drill body 1 and a limiting member 2. The drill body 1 has a central channel 11 with an installation port at one end. The cutter head 3 is disposed within the central channel 11 and can slide axially within the central channel 11. The cutter head 3 has an installation channel 31 inside, and the central drill 4 is slidably installed within the installation channel 31 and can move axially within the cutter head 3. The limiting member 2 is preferably a ring-shaped limiting ring, which is installed at the end of the drill body 1 near the installation port. It is fixedly connected by means of snap-fit ​​or thread, and is detachable, facilitating the replacement of limiting members 2 of different thicknesses or materials to adapt to different processing requirements. Structurally, this limiting ring is located at the end in the countersinking direction, which can form a stop during processing, controlling the further penetration of the cutter head 3, thereby effectively limiting the maximum depth of the countersink.

[0035] The sliding nature of the cutter head 3 within the central channel 11 allows for flexible adjustment of its position relative to the drill body 1, thereby altering the relative distance between its front countersinking cutter head and the limiting ring. The core principle of this structural design is that the control of the countersinking depth is not limited by the cutting edge length of the countersinking cutter itself, but rather by adjusting the fore-and-aft position of the cutter head 3 within the drill body 1, i.e., changing the travel distance before its foremost tip reaches the limiting member 2, thus achieving preset and precise control of the countersinking depth. Compared to traditional fixed countersinking structures, this design significantly improves the flexibility and versatility of the structure.

[0036] Meanwhile, the center drill 4, located inside the cutter head body 3, can slide axially along the mounting channel 31, allowing it to feed independently of the cutter head body 3. Its structural principle utilizes the free advance and retreat of the center drill 4 to control the drilling depth of the center hole—by adjusting the relative position of the center drill 4 within the cutter head body 3, its length protruding from the front end of the cutter head body 3 can be set, thus determining its maximum depth into the workpiece. This independent adjustment mechanism ensures that the depth control of the center hole and the countersunk hole does not interfere with each other. When meeting diverse processing needs, it eliminates the need for complete tool replacement or repeated trial drilling, significantly simplifying the operation and improving work efficiency and accuracy. Through this structure, a dual independent adjustment mechanism for the countersunk hole depth and the center hole depth is achieved. This not only offers convenient operation and a compact structure but also greatly improves the adaptability and reusability of the equipment. It is particularly suitable for woodworking and assembly operations where hole depth requirements are flexible and varied, demonstrating significant practical value and engineering application advantages.

[0037] To ensure the relative positioning accuracy between the cutter head body 3, the center drill 4, and the drill body 1 during the machining process, this application further provides a locking component 5. The locking component 5 includes a first fixing hole 51 located on one side of the cutter head body 3 and a second fixing hole 52 located on one side of the drill body 1. The first fixing hole 51 is connected to the mounting channel 31, and the second fixing hole 52 is connected to the center channel 11. It also includes fastening screws 53 that are threadedly connected to the first fixing hole 51 and the second fixing hole 52. A pair of fastening screws 53 respectively abut against one side of the center drill 4 and the cutter head body 3.

[0038] Specifically, such as Figure 2-4 As shown, the locking assembly 5 includes a first fixing hole 51 and a second fixing hole 52 respectively located on both sides of the cutter head body 3 and the drill body 1. The first fixing hole 51 connects to the mounting channel 31, and the second fixing hole 52 connects to the central channel 11. A pair of fastening screws 53 are threadedly installed inside the second fixing hole 52. The two screws abut against the outer walls of the central drill 4 and the cutter head body 3 respectively through the first fixing hole 51 and the second fixing hole 52. When it is necessary to lock the position of the central drill 4 and the cutter head body 3, the user can tighten the fastening screws 53. When the two screws are tightened, one fastening screw 53 will press the central drill 4 into the mounting channel 31 through the first fixing hole 51, thereby fixing the position between the central drill 4 and the cutter head body 3. The other fastening screw 53 will press the cutter head body 3 into the central channel 11 through the second fixing hole 52, thereby locking the position of the cutter head body 3. This locking structure allows for individual adjustment of the central drill 4 and the cutter head body 3, making the adjustment more precise.

[0039] When the locking component 5 is in the unlocked state, the cutter head 3 can move freely within the central channel 11. In order to ensure that the sliding of the cutter head 3 is more stable, a groove is provided on the periphery of the cutter head 3, and one end of the fastening screw 53 can abut against the surface of the groove, thereby restricting the circumferential rotation of the cutter head 3.

[0040] To achieve precise adjustment of the cutter head body 3 and improve the accurate control of the counterbore depth, a fine-tuning component 6 is also installed inside the drill body 1, such as... Figure 2-3As shown, the fine-tuning component 6 includes an adjustment channel 61 disposed within the drill body 1 and communicating with the central channel 11. The adjustment channel 61 is coaxially arranged with the central channel 11, and the adjustment channel 61 is located at the end of the central channel 11 away from the mounting port. It also includes a pin 62 threadedly connected to the adjustment channel 61. One end of the pin 62 is an abutment for driving the cutter head body 3, and the other end is a drive part for driving the pin 62 to rotate. The drive part is a groove disposed on the end face of the pin 62. The drill body 1 is provided with an operating channel 63 coaxial with and communicating with the adjustment channel 61. The operating channel 63 corresponds to the position of the groove. The operator can extend an external tool into the adjustment channel 61 through the operating channel 63 to control the rotation of the pin 62.

[0041] Specifically, the core structure of the fine-tuning component 6 consists of an adjustment channel 61 and a pin 62. The adjustment channel 61 is axially arranged along the drill body 1 and coaxially connected to the central channel 11, located at the end of the central channel 11 furthest from the mounting opening, i.e., the rear region of the drill body 1. A rotatable and advanceable pin 62 is threadedly installed inside the adjustment channel 61. The front end of the pin 62 has an abutment portion, used to directly press against the tail end of the cutter head body 3 during fine-tuning. Through this abutment relationship, each axial advance of the pin 62 causes the cutter head body 3 to slide forward along the central channel 11, achieving subtle changes in the distance between the cutter head body 3 and the limiting ring, thereby precisely controlling the upper limit of the counterbore depth.

[0042] The rear end of the pin 62 is provided with a driving part, preferably a groove structure. The groove structure can be a slotted groove, a cross groove, an internal hexagonal groove, a star groove, or a Torx groove, etc. The groove is located at the end face of the tail of the pin 62 and is used to insert an external tool for rotational driving. The external tool can be selected according to the structure of the groove. In this embodiment, the groove adopts an internal hexagonal groove, so the external tool can be an existing internal hexagonal wrench. In this application, the external tools are all existing tool products.

[0043] To facilitate the operator's external rotation of the pin 62, the drill body 1 is provided with an operating channel 63 that is coaxial with and communicates with the adjustment channel 61. This channel extends from the outer wall of the drill body 1 into the inner cavity of the adjustment channel 61, and its outlet position is precisely aligned with the groove. The operator can insert a screwdriver or special tool into the groove at the tail of the pin 62 through the operating channel 63, and rotate the tool to drive the pin 62 to rotate, causing it to slowly advance or retract along the thread structure, thereby indirectly driving the fine-tuning sliding of the cutter head 3 in the central channel 11.

[0044] The working principle of this fine-tuning structure is based on a spiral propulsion mechanism and local rigid force transmission. Through the close fit of the threaded pair, with each rotation of the pin 62, its front end continuously pushes the cutter head 3 with a very small stroke change, achieving stepless fine-tuning of the countersinking depth. This maintains the linear controllability of the adjustment process and avoids the problems of "large adjustment steps" and "inaccurate positioning" in traditional tools. Fine-tuning with the locking component 5 in the loose state ensures that the cutter head 3 always moves along the predetermined path without jumping or rebounding. After adjusting to the target position, locking is then performed to stably maintain the required depth setting. The above structure enhances the precision adjustment capability of this invention in depth control, eliminating the need for manual estimation or trial drilling verification in countersinking, which is particularly advantageous in operation scenarios requiring high repeatability or consistency across multiple parts. In addition, through the external control method guided by the operation channel 63, the operator can adjust the cutter head 3 in a fully enclosed state without disassembling the drill bit, greatly improving the convenience and efficiency of actual operation.

[0045] Furthermore, such as Figure 4 As shown, the cutter head body 3 includes an extension 32, and the end of the extension 32 is provided with a countersunk hole 33 with a cutting edge. The mounting channel 31 passes through the cutter head body 3. There are two countersunk holes 33, which are respectively provided at both ends of the extension 32. The countersunk holes machined by the two countersunk holes 33 have different diameters.

[0046] Specifically, the front end of the cutter head body 3 extends from the drill body 1 and is provided with a countersunk section 33. This countersunk section 33 has multiple cutting edges that perform circumferential cutting around the hole during rotation, thereby processing a recessed stepped hole. This allows the screw head to be fully embedded below the wood surface when installed, preventing protrusion and improving the aesthetics of the finished product. To meet the installation requirements of different screw diameters, the cutter head body 3 is preferably designed with a bidirectional countersunk structure, that is, its two ends are respectively provided with countersunk cutter heads of different diameters. Users only need to adjust the installation direction to process countersunk holes of different sizes without changing the cutter head body 3. The structure is more compact and the use is more flexible, suitable for scenarios where multiple specifications are used alternately on site, reducing the dependence on multiple specification accessories.

[0047] Regarding the design of the shank 7, this invention can be either integrally formed with the drill body 1 or can be a separate quick-release assembly method. In this embodiment, the shank 7 adopts a quick-release assembly method, wherein when the shank 7 and the drill body 1 are assembled separately, one end of the shank 7 is inserted into the operating channel 63, and a screwdriver head is provided at the end inserted into the operating channel 63.

[0048] The shank 7 and the operating channel 63 are detachably connected via a quick-connect structure 8. The quick-connect structure 8 includes an assembly hole 82 located on the periphery of the tail of the drill body 1 and an annular groove 81 located at one end of the shank 7 corresponding to the position of the assembly hole 82. The assembly hole 82 is perpendicular to and communicates with the operating channel 63. A ball bearing 83 is rolled inside the assembly hole 82. The quick-connect structure 8 also includes a connecting bushing 84 sleeved on the drill body 1. A return spring 86 is provided between the connecting bushing 84 and the drill body 1. A drive ring 85 is provided inside the connecting bushing 84. When the drive ring 85 of the connecting bushing 84 drives the return spring 86 to compress, a gap is created between the inner wall of the connecting bushing 84 and the assembly hole 82, allowing the ball bearing 83 to move outward to release the engagement between the shank 7 and the operating channel 63. When the return spring 86 drives the connecting bushing 84 to return and slide, the drive ring 85 inside the connecting bushing 84 will squeeze the ball bearing 83 inward to achieve engagement between the insertion hole and the shank 7.

[0049] Specifically, its plug-in end inserts into the operating channel 63 and is equipped with a screwdriver head for rotation control, allowing users to directly screw in screws through the tail end of the shank 7 after drilling, achieving a highly efficient "one-tool-multiple-purpose" operation. The quick-connect structure 8 between the shank 7 and the operating channel 63 consists of a mounting hole 82, annular groove 81, ball bearing 83, connecting bushing 84, return spring 86, and drive ring 85. When the shank 7 needs to be connected, simply compress the connecting bushing 84 to release the ball bearing 83's limit position, insert the shank 7, and release it; the ball bearing 83 returns to its original position, thus locking the shank 7. The reverse operation allows for quick disassembly. The entire process requires no tool intervention, improving loading and unloading efficiency and ensuring structural reliability.

[0050] Example 2

[0051] Based on Embodiment 1, the handle 7 in this embodiment is integrally molded, such as... Figure 5-6 As shown, when the shank 7 is integrally formed with the drill body 1, the operating channel 63 is provided through the shank 7; wherein, the shank 7 is provided as a hexagonal shank, a square shank, or a square interface, which can be connected to an external electric drill, thereby realizing the driving drilling operation of the limiting countersunk drill.

[0052] Example 3

[0053] Based on Example 1, since the limiting countersink drill has a relatively simple function and can only perform the function of limiting countersinking, in this example, the cutter head body 3 and twist drill on the drill body 1 can also be disassembled by controlling the set screw and replaced as needed to achieve other operating functions.

[0054] like Figure 7As shown, in this embodiment, a cutting head matching the drill bit is provided. It is a trimming and chamfering cutting head, but not limited to this type of cutting head. The cutting head provided in this embodiment includes a connecting rod 9 that is inserted into the central channel 11 of the drill body 1. A clamping surface 10 corresponding to the locking hole is provided on the periphery of the connecting rod 9. The set screw can pass through the locking hole and abut against the clamping surface 10 to achieve a locking connection of the connecting rod 9. A chamfering and trimming cutting head 101 is fixedly connected to the end of the connecting rod 9 away from the drill body 1. At the same time, a limiting plate 12 is provided on the drill body 1. When installing the limiting plate 12, the limiting member 2 can be disassembled first and then replaced with the limiting plate 12. The chamfering and trimming cutting head 101 passes through the limiting plate 12 and is located below the limiting plate 12.

[0055] In use, the user can connect the chamfering and trimming cutter head 101 to the drill body 1 via the connecting rod 9. The drill body 1 is then connected to the electric drill, which allows the electric drill to drive the chamfering and trimming cutter head 101 to rotate, thereby chamfering and repairing the edge corners of the material. The limiting plate 12 can fit against the material surface to ensure the horizontal movement of the cutter head. The chamfering and trimming cutter head is existing technology, and its specific structure will not be described in detail.

[0056] With the above-described chamfering and trimming cutter structure, users can achieve chamfering and trimming functions or drilling functions by replacing the cutter head on the drill body 1, which improves the practicality of the limiting countersunk drill, makes it easier for users to carry, and reduces the cost of the tool.

[0057] Meanwhile, the limiting plate 12 and the chamfering and trimming cutter head 101 are set separately, so that the length of the chamfering and trimming cutter head 101 can also be adjusted, thereby adjusting the chamfering depth.

[0058] In the accompanying drawings of this embodiment, the same or similar reference numerals correspond to the same or similar components. In the description of this application, it should be understood that if terms such as "upper," "lower," "left," and "right" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, they 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, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the accompanying drawings are only for illustrative purposes and should not be construed as limiting this patent. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0059] The above are merely preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A limiting countersinking device, comprising a drill body (1) and a limiting member (2), wherein the drill body (1) has a central channel (11) with an installation opening at one end, characterized in that, It also includes, The cutter head body (3) is disposed in the central channel (11) and can slide along the central channel (11) axially; the cutter head body (3) is provided with an installation channel (31); A center drill (4) is set in the installation channel (31) and can slide along the axial direction of the installation channel (31); Locking component (5) is used to lock the position of the cutter head body (3), the drill body (1), the center drill (4), and the cutter head body (3); The fine-tuning component (6) is used to drive the cutter head body (3) to move axially along the central channel (11) toward the mounting port direction to adjust the relative position between the cutter head body (3) and the limiting member (2) when the locking component (5) releases the lock between the cutter head body (3) and the drill body (1).

2. The limiting countersinking device according to claim 1, characterized in that, The locking assembly (5) includes a first fixing hole (51) disposed on one side of the cutter head body (3) and a second fixing hole (52) disposed on one side of the drill body (1). The first fixing hole (51) is connected to the mounting channel (31), and the second fixing hole (52) is connected to the central channel (11). It also includes fastening screws (53) threadedly connected to the first fixing hole (51) and the second fixing hole (52). A pair of fastening screws (53) respectively abut against one side of the central drill (4) and the cutter head body (3).

3. A limiting countersunk hole device according to claim 1 or 2, characterized in that, The fine-tuning component (6) includes an adjustment channel (61) disposed inside the drill body (1) and communicating with the central channel (11). The adjustment channel (61) is coaxially disposed with the central channel (11) and the adjustment channel (61) is located at the end of the central channel (11) away from the mounting port. It also includes a pin (62) threadedly connected to the adjustment channel (61). One end of the pin (62) is an abutment part for driving the cutter head body (3), and the other end is a driving part for driving the pin (62) to rotate.

4. A limiting countersunk hole device according to claim 3, characterized in that, The drive unit is a groove provided on the end face of the pin (62). The drill body (1) is provided with an operating channel (63) that is coaxial with and connected to the adjustment channel (61). The operating channel (63) corresponds to the position of the groove. The operator can extend the external tool into the adjustment channel (61) through the operating channel (63) to control the rotation of the pin (62).

5. A limiting countersunk hole device according to claim 1, characterized in that, The cutter head body (3) includes an extension (32), and the end of the extension (32) is provided with a countersunk hole (33) with a cutting edge.

6. A limiting countersunk hole device according to claim 5, characterized in that, The mounting channel (31) is provided through the cutter head body (3), and there are two countersunk holes (33), which are respectively provided at both ends of the extension (32). The countersunk holes processed by the two countersunk holes (33) have different diameters.

7. A limiting countersinking device according to claim 4, characterized in that, The drill body (1) is provided with a shank (7) at one end away from the center drill (4), and the shank (7) is integrally formed with the drill body (1) or separately combined.

8. A limiting countersunk hole device according to claim 7, characterized in that, When the shank (7) and the drill body (1) are assembled separately, one end of the shank (7) is inserted into the operating channel (63), and a screwdriver head is provided at the end inserted into the operating channel (63).

9. A limiting countersunk hole device according to claim 7, characterized in that, When the shank (7) and the drill body (1) are integrally formed, the operating channel (63) is provided through the shank (7).

10. A limiting countersunk hole device according to claim 8, characterized in that, The shank (7) and the operating channel (63) are detachably connected via a quick-connect structure (8). The quick-connect structure (8) includes an assembly hole (82) located on the periphery of the tail of the drill body (1) and an annular groove (81) located at one end of the shank (7) corresponding to the position of the assembly hole (82). The assembly hole (82) is perpendicular to and communicates with the operating channel (63). A ball bearing (83) is rolled inside the assembly hole (82). The quick-connect structure (84) also includes a connecting bushing (84) sleeved on the drill body (1). A return spring is provided between the connecting bushing (84) and the drill body (1). (86) A drive ring (85) is provided on the inner side of the connecting bushing (84); when the drive ring (85) of the connecting bushing (84) drives the return spring (86) to compress, a gap is generated between the inner wall of the connecting bushing (84) and the assembly hole (82) to allow the ball (83) to move outward so as to release the engagement between the handle (7) and the operating channel (63); when the return spring (86) drives the connecting bushing (84) to return to its original position and slide, the drive ring (85) inside the connecting bushing (84) will squeeze the ball (83) to move inward so as to achieve the engagement between the insertion hole and the handle (7).

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