Multi-station feeding mechanism of numerical control drilling machine
Patent Information
- Application Number
- CN202611249444.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-08-18
- Publication Date
- 2026-10-27
AI Technical Summary
整个流程需人工持续介入，重复操作劳动强度大；人员近距离面对高速旋转的钻头与丝锥，磕碰划伤风险极高，安全隐患严重
1.本发明提供一种数控攻钻机多工位上料机构，本设备集成了钻孔上料单元与攻丝上料单元，能够通过上料电动推杆自动推送原料，实现钻孔工序的连续送料；同时配合旋转舵机、旋转板及限位块，可灵活切换加工工位，完成攻丝工序的精准供料。摒弃了传统人工逐一取料、装夹和转运的作业方式，不仅有效降低了操作人员的劳动强度，也从根本上消除了手部靠近旋转刀具所带来的磕碰与划伤风险，显著提升了加工过程的安全性与自动化水平。
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Figure CN122975431A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of feeding mechanism technology, and in particular to a multi-station feeding mechanism for a CNC drilling machine. Background Technology
[0002] Electronic chassis are widely used in industrial control equipment, instruments, communications, power measurement and control and other fields. During assembly, the circuit board cannot be directly attached to the metal chassis base plate, which can easily lead to short circuits and make it difficult to reserve heat dissipation and electrical safety clearance. Therefore, the industry often uses cylindrical internal thread partition columns to support and fix the circuit board.
[0003] Currently, the processing of non-standard partition columns mostly employs separate operations of bench drills and small tapping machines, along with simple fixtures. Workpiece loading and clamping are entirely manual: workers must place and lock the cylindrical blanks one by one, remove the workpiece after drilling, and transfer it to the tapping position for re-clamping. The entire process requires continuous manual intervention, resulting in repetitive and labor-intensive operations. Workers are exposed to high-speed rotating drill bits and taps at close range, posing a significant risk of injury and serious safety hazards. Furthermore, manual clamping makes it difficult to ensure coaxiality, easily leading to quality problems such as drill misalignment and poor thread quality. Transferring between processes also easily results in bumps and missed areas, leading to insufficient processing efficiency and product consistency, making it difficult to meet the demands of mass production. Therefore, there is an urgent need to provide a multi-station loading mechanism for CNC drilling and tapping machines to solve these problems. Summary of the Invention
[0004] The purpose of this invention is to provide a multi-station feeding mechanism for a CNC drilling machine, which solves the technical problems mentioned in the background art.
[0005] To achieve the above objectives, the present invention provides the following technical solution: a multi-station feeding mechanism for a CNC drilling machine, comprising an equipment frame, a drilling assembly and a tapping assembly disposed on the equipment frame, a drilling feeding unit and a cleaning unit disposed on the equipment frame, and a tapping feeding unit disposed on the right side of the drilling feeding unit; The drilling and feeding unit includes a guide frame and a pusher frame. The rear side of the guide frame is connected to a feeding frame. An electric pusher rod for feeding is fixedly connected to the outer wall of the guide frame. The output end of the electric pusher rod for feeding is connected to the left end of the pusher frame. The right end of the pusher frame extends into the guide frame. Both the front and rear side walls of the pusher frame penetrate the left side wall of the guide frame. Both the front and rear side walls of the pusher frame are slidably connected to the left side wall of the guide frame. The tapping and feeding unit includes a rotating plate, a rotating servo motor, and an annular tapping and feeding frame. The tapping and feeding frame is located behind the cleaning unit. The right end of the feeding frame is connected to the tapping and feeding frame. The rotating plate is located inside the tapping and feeding frame. The rotating servo motor is fixed inside the equipment frame. The output end of the rotating servo motor passes through the upper side wall of the equipment frame and is fixedly connected to the lower end of the rotating plate. Two centrally symmetrically arranged limiting blocks are fixedly connected to the circumferential side wall of the rotating plate. A limiting groove is opened at the end of the limiting block away from the rotating plate.
[0006] Preferably, the right end of the tapping and feeding frame is connected to a limiting frame, and the right end of the limiting frame is connected to an abutting electric push rod. The output end of the abutting electric push rod passes through the right side wall of the limiting frame and is connected to an abutting block. A push rod is provided below the rotating plate, and the push rod is located on the left side of the limiting frame.
[0007] Preferably, the electric push rod is fixed on the equipment frame, and a push block is fixedly connected to the output end of the electric push rod; The bottom of the limiting groove is provided with a discharge operation hole, and the outer diameter of the pusher block is smaller than the inner diameter of the discharge operation hole.
[0008] Preferably, a finished product export frame is provided below the limiting frame and located inside the equipment frame. The upper end of the finished product export frame is fixedly connected to the upper inner wall of the equipment frame, and the right end of the finished product export frame passes through the side wall of the equipment frame and extends to the outside of the equipment frame. Both the lower side wall of the limiting frame and the upper side wall of the equipment frame are provided with discharge ports, which are located at the upper end of the finished product export frame.
[0009] Preferably, the lower side wall of the tapping and feeding frame and the equipment frame have two connected slag discharge ports, which are located below the cleaning unit.
[0010] Preferably, the cleaning unit includes a fixed frame fixed to the equipment frame, a cleaning electric push rod fixedly connected to the upper end of the fixed frame, the output end of the cleaning electric push rod passing through the upper side wall of the fixed frame and fixedly connected to a lifting plate, a cleaning motor fixedly connected to the lower end of the lifting plate, a rotating rod connected to the output end of the cleaning motor, a push plate fixedly connected to the lower end of the rotating rod, and a cleaning brush provided on the side wall of the rotating rod.
[0011] Preferably, auxiliary plates are fixed on both the left and right side walls of the fixed frame, and a limiting slide rod is fixed at the upper end of the auxiliary plate. The upper end of the limiting slide rod passes through the lifting plate and is fixedly connected to the upper side wall of the fixed frame.
[0012] Preferably, an abutment frame is provided on the outer side of the push plate, and two sliding rods are fixedly connected to the upper end of the abutment frame. The upper end of the sliding rod passes through the lifting plate and is connected to the top plate. An abutment spring is sleeved on the sliding rod, and the two ends of the abutment spring are respectively connected to the adjacent side walls of the lifting plate and the abutment frame.
[0013] Preferably, both the upper sidewall of the tapping and feeding frame and the upper sidewall of the equipment frame have two through holes, which are located below the drilling assembly and the tapping assembly, respectively.
[0014] Compared with related technologies, the multi-station feeding mechanism for a CNC drilling machine provided by the present invention has the following beneficial effects: 1. This invention provides a multi-station feeding mechanism for a CNC drilling machine. This equipment integrates a drilling feeding unit and a tapping feeding unit, enabling automatic material feeding via an electric feeding pusher for continuous material feeding during the drilling process. Simultaneously, in conjunction with a rotary servo motor, a rotary plate, and limit blocks, it can flexibly switch processing stations to achieve precise material feeding for the tapping process. This eliminates the traditional manual method of picking up, clamping, and transferring materials one by one, effectively reducing the labor intensity of operators and fundamentally eliminating the risk of bumps and scratches to hands near the rotating cutting tool, significantly improving the safety and automation level of the processing.
[0015] 2. This invention provides a multi-station feeding mechanism for a CNC drilling and tapping machine. This device includes a cleaning unit between the drilling and tapping processes, which automatically removes residual metal shavings from the workpiece hole, effectively preventing shavings from affecting the subsequent tapping thread profile forming accuracy, thereby ensuring thread engagement quality. After processing, the workpiece is discharged through the outlet into the finished product ejector frame for centralized discharge. Attached Figure Description
[0016] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram showing the internal structure of the device frame of the present invention; Figure 3 This is a schematic diagram showing the position and structure of the drilling and tapping feeding unit and the tapping feeding unit of the present invention; Figure 4 For the present invention Figure 3 Enlarged view of a portion of point A in the middle; Figure 5 For the present invention Figure 3 Enlarged view of section B in the middle; Figure 6 For the present invention Figure 3 Enlarged view of a section at point C; Figure 7 This is a partial structural diagram of the present invention; Figure 8This is a cross-sectional three-dimensional structural diagram of the present invention; Figure 9 For the present invention Figure 8 Enlarged view of a section at point D; Figure 10 This is a three-dimensional structural diagram of the cleaning unit of the present invention; Figure 11 For the present invention Figure 10 Enlarged view of a section at point E in the middle; Figure 12 This is a three-dimensional structural diagram of the cleaning brush position of the present invention.
[0017] In the diagram: 1. Equipment frame; 2. Drilling assembly; 3. Tapping assembly; 4. Drilling feeding unit; 401. Feeding frame; 402. Guide frame; 403. Feeding electric push rod; 404. Pushing frame; 5. Tapping feeding unit; 501. Tapping feeding frame; 502. Rotating plate; 503. Rotating servo motor; 504. Limiting block; 505. Through hole; 506. Limiting groove; 507. Limiting frame; 508. Abutment block; 509. Discharge port; 510. Abutment electric push rod 511. Electric push rod for material feeding; 512. Push block; 513. Discharge operation hole; 514. Slag discharge port; 6. Cleaning unit; 601. Fixing frame; 602. Electric push rod for cleaning; 603. Auxiliary plate; 604. Limiting slide bar; 605. Lifting plate; 606. Cleaning motor; 607. Sliding rod; 608. Abutment spring; 609. Top plate; 610. Abutment frame; 611. Rotating rod; 612. Push plate; 613. Cleaning brush; 7. Finished product discharge frame. Detailed Implementation
[0018] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention. Example:
[0019] Please see Figures 1-12 The present invention provides a technical solution: a multi-station feeding mechanism for a CNC drilling machine, including a device frame 1, a drilling assembly 2 and a tapping assembly 3 on the device frame 1, a drilling feeding unit 4 and a cleaning unit 6 on the device frame 1, and a tapping feeding unit 5 on the right side of the drilling feeding unit 4. The drilling and feeding unit 4 includes a guide frame 402 and a pusher frame 404. The rear side of the guide frame 402 is connected to a feeding frame 401. The rear end of the feeding frame 401 is inclined upwards, and the billet rolls down in an orderly manner by its own weight, ensuring continuous feeding of the billet and preventing jamming and stacking. The outer wall of the guide frame 402 is fixedly connected to a feeding electric push rod 403. The output end of the feeding electric push rod 403 is connected to the left end of the pusher frame 404. The right end of the pusher frame 404 extends into the guide frame 402. The front and rear side walls of the pusher frame 404 penetrate the left side wall of the guide frame 402, and the front and rear side walls of the pusher frame 404 are slidably connected to the left side wall of the guide frame 402. By reciprocating pushing and pulling the pusher frame 404 with the feeding electric push rod 403, the single billet can be accurately pushed and fed. During the push return stroke, the side wall of the pusher frame 404 can be used to block the feeding channel, avoiding the problem of multiple billets rushing in at the same time and causing blockage. The tapping and feeding unit 5 includes a rotating plate 502, a rotating servo motor 503, and an annular tapping and feeding frame 501. The tapping and feeding frame 501 is located behind the cleaning unit 6. The right end of the feeding frame 401 is connected to the tapping and feeding frame 501. The rotating plate 502 is located inside the tapping and feeding frame 501. The rotating servo motor 503 is fixed inside the equipment frame 1. The output end of the rotating servo motor 503 passes through the upper side wall of the equipment frame 1 and is fixedly connected to the lower end of the rotating plate 502. Two centrally symmetrically arranged limiting blocks 504 are fixedly connected to the circumferential side wall of the rotating plate 502. A limiting groove 506 is opened at the end of the limiting block 504 away from the rotating plate 502. The two sets of limiting grooves 506 can alternately carry the workpiece, and sequentially complete the switching of drilling, chip removal, and tapping stations to achieve multi-station synchronous parallel operation and improve the overall processing cycle. The right end of the tapping feed frame 501 is connected to the limiting frame 507. The right end of the limiting frame 507 is connected to the abutment electric push rod 510. The output end of the abutment electric push rod 510 passes through the right side wall of the limiting frame 507 and is connected to the abutment block 508. The inner side wall of the limiting groove 506, the left and right ends of the abutment block 508, and the right end of the push frame 404 are all provided with anti-slip grooves. During the tapping operation, the abutment block 508 and the limiting groove 506 cooperate to clamp the cylindrical workpiece, limit the radial displacement of the workpiece, ensure the coaxiality of the tapping process, and prevent the workpiece from rotating and slipping. A pusher electric push rod 511 is provided below the rotating plate 502. The pusher electric push rod 511 is located on the left side of the limiting frame 507. The pusher electric push rod 511 is fixed on the equipment frame 1. A pusher block 512 is fixedly connected to the output end of the pusher electric push rod 511. A discharge operation hole 513 is opened at the bottom of the limiting groove 506. The outer diameter of the pusher block 512 is smaller than the inner diameter of the discharge operation hole 513. Both the lower side wall of the limiting frame 507 and the upper side wall of the equipment frame 1 are provided with discharge ports 509, and the discharge ports 509 are located at the upper end of the finished product export frame 7. After the tapping operation is completed, the abutting electric push rod 510 drives the abutting block 508 to reset to the right and move to the right side of the discharge port 509. The pushing electric push rod 511 drives the pushing block 512 to move. The pushing block 512 passes through the discharge operation hole 513 and pushes the blank to the right. When the blank moves to the discharge port 509, it falls into the finished product export frame 7 and is exported from the finished product export frame 7. Below the limiting frame 507, there is a finished product export frame 7 located inside the equipment frame 1. The upper end of the finished product export frame 7 is fixedly connected to the upper inner wall of the equipment frame 1, and the right end of the finished product export frame 7 passes through the side wall of the equipment frame 1 and extends to the outside of the equipment frame 1. Two connected slag discharge ports 514 are provided on the lower side wall of the tapping feeding frame 501 and on the equipment frame 1. The slag discharge ports 514 are located below the cleaning unit 6. Metal shavings generated by drilling and chip removal can be discharged uniformly through the slag discharge ports 514 to avoid the accumulation of debris and contamination of the work station, and to avoid affecting subsequent tapping operations. The cleaning unit 6 includes a fixed frame 601 fixed on the equipment frame 1. A cleaning electric push rod 602 is fixedly connected to the upper end of the fixed frame 601. The output end of the cleaning electric push rod 602 passes through the upper side wall of the fixed frame 601 and is fixedly connected to a lifting plate 605. A cleaning motor 606 is fixedly connected to the lower end of the lifting plate 605. A rotating rod 611 is connected to the output end of the cleaning motor 606. A push plate 612 is fixedly connected to the lower end of the rotating rod 611. A cleaning brush 613 is provided on the side wall of the rotating rod 611. Auxiliary plates 603 are fixed on both the left and right side walls of the fixed frame 601. A limit slide rod 604 is fixed to the upper end of the auxiliary plate 603. The upper end of the limit slide rod 604 passes through the lifting plate 605 and is fixedly connected to the upper side wall of the fixed frame 601. An abutment frame 610 is provided on the outer side of the push plate 612. Two sliding rods 607 are fixedly connected to the upper end of the abutment frame 610. The upper end of the sliding rod 607 passes through the lifting plate 605 and is connected to the top plate 609. An abutment spring 608 is sleeved on the sliding rod 607. The two ends of the abutment spring 608 are respectively connected to the adjacent side walls of the lifting plate 605 and the abutment frame 610. In use, the abutment spring 608 provides elastic pre-tightening force, and the abutment frame 610 presses down and adheres to the upper end surface of the workpiece for stable positioning, so as to prevent the blank from rotating when the rotating rod 611 drives the cleaning brush 613 to rotate to clean the drill hole. Two through holes 505 are provided on the upper side wall of the tapping and feeding frame 501 and the upper side wall of the equipment frame 1. The two through holes 505 are located below the drilling assembly 2 and the tapping assembly 3, respectively. The through holes 505 are set to reserve operating space for the drill bit at the lower end of the drilling assembly 2 and the tapping assembly 3, thereby ensuring the normal processing of the through holes of the blank.
[0020] Working principle: During use, the cylindrical blank to be processed is pre-stored in the feeding frame 401. The feeding electric push rod 403 in the drilling and feeding unit 4 drives the pushing frame 404 to move to the right, pushing the blank into the guide frame 402 into the processing work. At this time, the limiting block 504 is located on the right side of the guide frame 402. As the feeding electric push rod 403 works, the blank enters the limiting groove 506. Under the action of the feeding electric push rod 403, the blank is clamped and limited. At this time, the drilling assembly 2 moves downward to perform drilling operation on the blank. At the same time, the rear side wall of the pushing frame 404 blocks the blank in the feeding frame 401, preventing the blank from entering the guide frame 402. After the blank is drilled, the rotary servo motor 503 drives the rotating plate 502 and the limiting block 504 to rotate. The limiting groove 506 moves the blank to the bottom of the cleaning mechanism. In the cleaning mechanism, the cleaning electric push rod 602 drives the lifting plate 605 to move downward. At the same time, the cleaning motor 606 drives the rotating rod 611 to rotate. The lower end of the abutment frame 610 first abuts against the upper end of the blank. As the lifting plate 605 moves downward, the push plate 612 at the lower end of the rotating rod 611 moves downward. The push plate 612 cleans the residue in the drill hole and pushes it out from the slag discharge port 514. While the rotating rod 611 is rotating, the cleaning brush 613 cleans the inside of the drill hole. After cleaning is completed, the cleaning electric push rod 602 drives the cleaning motor 606 and the lifting plate 605 to move upward. When the lower end of the abutment frame 610 separates from the upper end of the blank, the rotating servo motor 503 drives the rotating plate 502 to rotate again. Under the action of the limiting block 504, the blank is moved to the lower part of the tapping assembly 3. At this time, the limiting block 504 on the other side moves to the lower part of the drilling assembly 2. Under the action of the drilling and feeding unit 4, the drilling and feeding operation is performed. For the blank located below the tapping, the abutment electric push rod 510 pushes the abutment block 508 to move towards the blank. By cooperating with the limiting groove 506, the blank is clamped and positioned. After positioning, the tapping operation is completed by the tapping assembly 3. After the tapping operation is completed, the abutting electric push rod 510 drives the abutting block 508 to reset to the right and move to the right side of the discharge port 509. The pushing electric push rod 511 drives the pushing block 512 to move. The pushing block 512 passes through the discharge operation hole 513 and pushes the blank to the right. When the blank moves to the discharge port 509, it falls into the finished product export frame 7 and is exported from the finished product export frame 7.
[0021] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, the phrase "comprising an element defined as..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.
[0022] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.
Claims
1. A multi-station feeding mechanism for a CNC drilling machine, comprising a machine frame (1), wherein a drilling assembly (2) and a tapping assembly (3) are disposed on the machine frame (1), characterized in that: The equipment frame (1) is provided with a drilling and feeding unit (4) and a cleaning unit (6), and a tapping and feeding unit (5) is provided on the right side of the drilling and feeding unit (4). The drilling and feeding unit (4) includes a guide frame (402) and a pusher frame (404). The rear side of the guide frame (402) is connected to a feeding frame (401). The outer side wall of the guide frame (402) is fixedly connected to a feeding electric push rod (403). The output end of the feeding electric push rod (403) is connected to the left side of the pusher frame (404). The right side of the pusher frame (404) extends into the guide frame (402). The front and rear side walls of the pusher frame (404) both penetrate the left side wall of the guide frame (402). The front and rear side walls of the pusher frame (404) are slidably connected to the left side wall of the guide frame (402). The tapping and feeding unit (5) includes a rotating plate (502), a rotating servo motor (503), and an annular tapping and feeding frame (501). The tapping and feeding frame (501) is located behind the cleaning unit (6). The right end of the feeding frame (401) is connected to the tapping and feeding frame (501). The rotating plate (502) is located inside the tapping and feeding frame (501). The rotating servo motor (503) is fixed inside the equipment frame (1). The output end of the rotating servo motor (503) passes through the upper side wall of the equipment frame (1) and is fixedly connected to the lower end of the rotating plate (502). Two centrally symmetrically arranged limiting blocks (504) are fixedly connected to the circumferential side wall of the rotating plate (502). A limiting groove (506) is opened at the end of the limiting block (504) away from the rotating plate (502).
2. The multi-station feeding mechanism for a CNC drilling machine according to claim 1, characterized in that: The right end of the tapping and feeding frame (501) is connected to the limiting frame (507), and the right end of the limiting frame (507) is connected to the abutting electric push rod (510). The output end of the abutting electric push rod (510) passes through the right side wall of the limiting frame (507) and is connected to the abutting block (508). A pusher rod (511) is provided below the rotating plate (502), and the pusher rod (511) is located on the left side of the limiting frame (507).
3. The multi-station feeding mechanism for a CNC drilling machine according to claim 2, characterized in that: The electric push rod (511) is fixed on the equipment frame (1), and the output end of the electric push rod (511) is fixedly connected to the push block (512). The bottom of the limiting groove (506) is provided with a discharge operation hole (513), and the outer diameter of the pusher block (512) is smaller than the inner diameter of the discharge operation hole (513).
4. The multi-station feeding mechanism for a CNC drilling machine according to claim 2, characterized in that: Below the limiting frame (507) is a finished product export frame (7) located inside the equipment frame (1). The upper end of the finished product export frame (7) is fixedly connected to the upper inner wall of the equipment frame (1), and the right end of the finished product export frame (7) passes through the side wall of the equipment frame (1) and extends to the outside of the equipment frame (1). The lower side wall of the limiting frame (507) and the upper side wall of the equipment frame (1) are both provided with discharge ports (509), and the discharge ports (509) are located at the upper end of the finished product export frame (7).
5. The multi-station feeding mechanism for a CNC drilling machine according to claim 1, characterized in that: Two connected slag discharge ports (514) are provided on the lower side wall of the tapping and feeding frame (501) and the equipment frame (1), and the slag discharge ports (514) are located below the cleaning unit (6).
6. The multi-station feeding mechanism for a CNC drilling machine according to claim 1, characterized in that: The cleaning unit (6) includes a fixed frame (601) fixed on the equipment frame (1). A cleaning electric push rod (602) is fixedly connected to the upper end of the fixed frame (601). The output end of the cleaning electric push rod (602) passes through the upper side wall of the fixed frame (601) and is fixedly connected to a lifting plate (605). A cleaning motor (606) is fixedly connected to the lower end of the lifting plate (605). A rotating rod (611) is connected to the output end of the cleaning motor (606). A push plate (612) is fixedly connected to the lower end of the rotating rod (611). A cleaning brush (613) is provided on the side wall of the rotating rod (611).
7. The multi-station feeding mechanism for a CNC drilling machine according to claim 6, characterized in that: Auxiliary plates (603) are fixed on both the left and right side walls of the fixed frame (601). A limiting slide rod (604) is fixed on the upper end of the auxiliary plate (603). The upper end of the limiting slide rod (604) passes through the lifting plate (605) and is fixedly connected to the upper side wall of the fixed frame (601).
8. The multi-station feeding mechanism for a CNC drilling machine according to claim 6, characterized in that: An abutment frame (610) is provided on the outside of the push plate (612). Two sliding rods (607) are fixedly connected to the upper end of the abutment frame (610). The upper end of the sliding rod (607) passes through the lifting plate (605) and is connected to the top plate (609). An abutment spring (608) is sleeved on the sliding rod (607). The two ends of the abutment spring (608) are respectively connected to the adjacent side walls of the lifting plate (605) and the abutment frame (610).
9. The multi-station feeding mechanism for a CNC drilling machine according to claim 1, characterized in that: The upper side wall of the tapping and feeding frame (501) and the upper side wall of the equipment frame (1) are provided with two through holes (505), and the two through holes (505) are located below the drilling assembly (2) and the tapping assembly (3), respectively.