Drilling device for high-precision machining

Abstract

The utility model provides a drilling device for high-precision machining, and relates to the field of drilling machine structures. The floating centering mechanism comprises a centering base, a sleeve, a centering pipe, an inner hole and a floating piece, the centering base is connected to the tool apron, the sleeve is elastically and slidably connected to the centering base and connected with the centering pipe through the floating piece, the inner hole is formed in the centering pipe, the axis of the inner hole coincides with the theoretical rotation axis of the tool apron, and the floating piece is arranged on the tool apron. The inner hole and the cutting diameter of a drill bit installed in the tool apron are arranged in a clearance mode, the end of the centering pipe makes contact with a workpiece to be machined prior to the drill bit, and by making contact with the workpiece in advance and providing close-range guiding, the initial deflection of the drill bit is obviously reduced, and the hole site precision is guaranteed; the floating design allows the guide sleeve to have certain self-adaptive compensation capacity for slight unevenness or angular deviation of the surface of the workpiece, and the perpendicularity of drilling is improved. The design of the conical surface / spherical surface contact end enhances the adaptability to different surfaces.

Description

Technical Field

[0001] This utility model relates to the field of drilling machine structure, and in particular to a drilling device for high-precision machining. Background Technology

[0002] In precision machining, drilling operations place high demands on the positional accuracy, roundness, perpendicularity, and surface finish of holes. Traditional drilling methods, especially when a pre-drilled center hole is not present or the workpiece surface is uneven, are prone to drill bit wobble or "travel" upon initial contact with the workpiece, leading to inaccurate initial positioning. Simultaneously, vibrations generated during drilling are transmitted to both the drill bit and the workpiece, affecting hole quality and tool life. While existing technologies utilize drill bushings (drill jig bushings) to improve positioning accuracy, their relatively fixed structure makes them unsuitable for complex curved surfaces or scenarios requiring frequent drill diameter changes, and their vibration reduction effect is limited. Utility Model Content

[0003] In order to overcome the above-mentioned defects of the prior art, the present invention provides a high-precision drilling device for machining. The technical problem to be solved by the present invention is: how to overcome the defects of the existing drilling device that is prone to wobbling during initial positioning, large vibration during drilling, and low precision.

[0004] To achieve the above objectives, this utility model provides the following technical solution: a high-precision machining drilling device, including a drilling machine and a tool holder; a floating centering mechanism, including a centering base, a sleeve, a centering tube, an inner hole, and a floating element. The centering base is connected to the tool holder, and the sleeve is elastically slidably connected to the centering base. The sleeve is connected to the centering tube through the floating element. An inner hole is provided inside the centering tube, and the axis of the inner hole coincides with the theoretical rotation axis of the tool holder. The inner hole and the cutting diameter of the drill bit installed in the tool holder are separated by a gap. The end of the centering tube contacts the workpiece to be processed preferentially before the drill bit.

[0005] In a preferred embodiment, the end face of the centering tube that contacts the workpiece is an arc-shaped surface.

[0006] In a preferred embodiment, the thickness of the floating element is between 0.1 mm and 0.5 mm.

[0007] In a preferred embodiment, the ratio of the length of the inner hole to the cutting diameter of the drill bit is between 1.5 and 3.0.

[0008] In a preferred embodiment, the drilling machine further includes a support, a motor, and a rotating shaft. The support is arranged on the machining table, the motor is mounted on the support, and a rotating shaft is coupled inside the support. The rotating shaft is connected to the output shaft of the motor through a transmission device.

[0009] The technical effects and advantages of this utility model are as follows:

[0010] 1. By pre-contacting the workpiece and providing close-range guidance, the initial runout of the drill bit is significantly reduced, ensuring hole position accuracy.

[0011] 2. Viscous and elastic damping materials and elastic mechanisms can effectively absorb high-frequency vibrations during drilling, improve hole wall smoothness and roundness, and extend tool life.

[0012] 3. The floating design allows the guide sleeve to adaptively compensate for slight unevenness or angular deviations on the workpiece surface, improving the perpendicularity of the drilled hole. The conical / spherical contact end design enhances adaptability to different surfaces.

[0013] 4. It mainly relies on springs, damping materials and precisely matched mechanical structures to achieve its functions. It does not have complex sensors or control systems, so it has low cost, high reliability and is easy to maintain.

[0014] 5. It can be installed as an independent accessory on existing drilling machines or machining centers, making modification convenient. Attached Figure Description

[0015] The disclosure of this utility model is illustrated with reference to the accompanying drawings. It should be understood that the drawings are for illustrative purposes only and are not intended to limit the scope of protection of this utility model. In the drawings, the same reference numerals are used to refer to the same parts. Wherein:

[0016] Figure 1 This is a structural diagram of the drilling device of this utility model.

[0017] Figure 2 This is a side view of the drilling device of this utility model.

[0018] Figure 3 This is a cross-sectional view of the floating centering mechanism of this utility model.

[0019] The attached figures are labeled as follows: 10, drilling machine; 11, support; 12, motor; 13, shaft; 20, floating centering mechanism; 21, centering base; 22, sleeve; 23, centering tube; 24, inner hole; 25, floating component. Detailed Implementation

[0020] It is readily understood that, based on the technical solution of this utility model, those skilled in the art can propose various interchangeable structural methods and implementations without altering the essential spirit of this utility model. Therefore, the following detailed embodiments and accompanying drawings are merely illustrative descriptions of the technical solution of this utility model and should not be considered as the entirety of this utility model or as limitations or restrictions on the technical solution of this utility model.

[0021] Example

[0022] like Figures 1-3 This device includes a drilling machine 10 and a floating centering mechanism 20. The drilling machine 10 is a common bench drill or other type of drilling machine. The floating centering mechanism 20 is mounted on the drilling machine 10 to improve the accuracy of the drill bit's landing point at the beginning of machining.

[0023] The drilling machine 10 in this embodiment is an existing device that can independently perform drilling under manual operation after being plugged in. It mainly includes a support 11, a motor 12, and a rotating shaft 13. The support 11 is positioned at the machining location, the motor 12 is mounted on the support 11 and electrically connected to the mains power, and the rotating shaft 13 is mounted on the support 11. The motor 12 drives the rotating shaft 13 to rotate through a transmission mechanism. Simultaneously, rotating the handle on the support 11 moves the rotating shaft 13 downwards during rotation. A tool holder is mounted at the end of the rotating shaft 13, and the drill bit is installed in the tool holder. All of the above structures are existing technology. The movement of the rotating shaft 13 includes both rotation and vertical sliding; therefore, it can be said that the rotating shaft 12 is coupled to the support 11.

[0024] It should be noted that the support 11, motor 12 and shaft 13 are certain components within the drill press 10. They are described separately to better explain the improvements in the floating centering mechanism 20, and are not additional structures designed separately.

[0025] The floating centering mechanism 20 includes a centering base 21, a sleeve 22, a centering tube 23, an inner hole 24, and a floating element 25. The centering base 21 is fixed to flange one by threaded fasteners. Flange two is also fixed to the rotating shaft 13 by threaded fasteners. Flange one and flange two are fixed together by bolts. The sleeve 22 and the centering base 21 are slidably connected along their axes by a spring. The middle part of the sleeve 22 is hollow, and the tool holder can extend into the inner cavity of the sleeve 22. The lower part of the sleeve 22 is movably connected to the centering tube 23 by the floating element 25. The centering tube 23 has an inner hole 24. The drill bit on the tool holder that extends into the inner cavity of the sleeve 22 can pass through the inner hole 24 and then extend out. In the design, the inner diameter of the inner hole 24 is slightly larger than the cutting diameter of the drill bit.

[0026] With the above design, when the power of the sleeve 22 is turned on, the motor 12 drives the rotating shaft 13 to rotate. At this time, the user turns the handle to drive the rotating shaft 13 to move downward. The rotating shaft 13 drives the floating centering mechanism 20 to move downward as a whole. The end of the centering tube 23 will first touch the surface of the workpiece. Then the rotating shaft 13 continues to move downward. The centering base 21 gradually squeezes the spring and shortens the distance between the centering base 21 and the sleeve 22. At this time, the sleeve 22 drives the centering tube 23 to press on the surface of the workpiece with a certain pressure. Then the rotating shaft 13 continues to move downward. At this time, the drill bit will gradually extend out of the inner hole 24 under the drive of the downward rotating shaft 13 and drill the workpiece.

[0027] To further explain, let's define the actual rotation centerline of the drill bit as D, and the centerline established after the guide sleeve contacts the workpiece as P. Due to factors such as machine tool positioning accuracy, workpiece installation error, and local unevenness on the workpiece surface, there will be a deviation Δ between D and P. When the drill bit begins to enter the inner hole 24, if there is a deviation Δ, the side of the drill bit, usually the core or guide strip, will contact the inner wall of the inner hole 24. The drill bit will attempt to move downward along its own rotation centerline D, which will exert a radial force on the centering tube 23, attempting to push the centering tube 23 to a position coinciding with the drill bit's centerline D. Due to the presence of the floating element 25, the centering tube 23 is floating, and its radial position is maintained by the floating element 25. The radial force from the drill bit will overcome the restoring force of the floating element 25, causing the centering tube 23 to undergo a small radial displacement, and its centerline P will move closer to the drill bit's centerline D.

[0028] Before the drill bit contacts the workpiece, the centering tube 23 precisely determines the starting point of the drill hole through its lower end face contact with the workpiece, preventing the drill bit from slipping or deviating on smooth or uneven surfaces. Even if the centering tube 23 experiences slight radial movement, its inner hole 24 still tightly constrains the drill bit body at the millimeter-level distance before it cuts into the workpiece. This greatly limits the oscillation range of the drill tip, ensuring the initial perpendicularity of the drill hole and preventing the drill bit from starting drilling at an angle. Without the intervention of the floating element 25, if the centering tube 23 were completely rigid, this small deviation Δ would cause huge lateral stress between the drill bit and the centering tube 23, potentially damaging the drill bit edge, wearing the guide sleeve, or even causing the drill hole to deviate. The floating design alleviates this stress by allowing small displacements, enabling the drill bit to enter more smoothly. Ultimately, the drilling system reaches a new dynamic equilibrium: the centering tube 23 deviates slightly from its initial contact position and aligns with the drill bit's centerline, while the drill bit begins drilling under the close constraint of the centering tube 23. This final drilling position is a compromise between the initial positioning point P and the drill bit's axis D, very close to point P, but the key is a smooth process, no stress concentration, and controlled initial entry.

[0029] Therefore, it can be said that the core positioning function of the central tube 23 is to accurately position the starting point on the workpiece surface before the drill bit contacts the workpiece and eliminate the initial slippage.

[0030] When the drill bit enters the centering tube 23, if there is a slight deviation, the floating compensation of the floating component 25 is to adapt to this deviation, avoid problems caused by rigid collisions, and continuously provide guiding constraints at very close distances to ensure that the drill bit starts cutting stably and vertically.

[0031] Preferably, the material of the floating member 25 can be one of nitrile rubber, polyurethane rubber, neoprene rubber or others, and the material is made into a collar structure existing between the centering joint 23 and the sleeve 22.

[0032] It should be noted that when the end of the centering tube 23 is pressed against the workpiece, the end of the centering tube 23 is simultaneously subjected to axial positive pressure and positive pressure provided by the contact surface, which can prevent the centering tube 23 from being removed from the workpiece during drilling.

[0033] Furthermore, while it cannot be guaranteed that absolutely no tiny particles will occasionally enter the inner bore 24, under normal drilling processes and with sufficient coolant, the main chip removal path is away from the guide hole. Combined with the close contact between the guide sleeve and the workpiece, the possibility of a large amount of chips entering the precision inner bore and causing jamming or severe wear is greatly reduced, and usually does not pose a serious problem. In special cases where extremely high cleanliness is required, auxiliary methods such as compressed air purging may also be necessary.

[0034] In summary, the advantages of this embodiment are as follows.

[0035] 1. By pre-contacting the workpiece and providing close-range guidance, the initial runout of the drill bit is significantly reduced, ensuring hole position accuracy.

[0036] 2. Viscous and elastic damping materials and elastic mechanisms can effectively absorb high-frequency vibrations during drilling, improve hole wall smoothness and roundness, and extend tool life.

[0037] 3. The floating design allows the guide sleeve to adaptively compensate for slight unevenness or angular deviations on the workpiece surface, improving the perpendicularity of the drilled hole. The conical / spherical contact end design enhances adaptability to different surfaces.

[0038] 4. It mainly relies on springs, damping materials and precisely matched mechanical structures to achieve its functions. It does not have complex sensors or control systems, so it has low cost, high reliability and is easy to maintain.

[0039] 5. It can be installed as an independent accessory on existing drilling machines or machining centers, making modification convenient.

[0040] The technical scope of this utility model is not limited to the content described above. Those skilled in the art can make various modifications and variations to the above embodiments without departing from the technical concept of this utility model, and all such modifications and variations should fall within the protection scope of this utility model.

Claims

1. A drilling device for high-precision machining, characterized in that, include: Drilling machine (10), including tool holder; The floating centering mechanism (20) includes a centering base (21), a sleeve (22), a centering tube (23), an inner hole (24), and a floating element (25). The centering base (21) is connected to the tool holder. The sleeve (22) is elastically slidably connected to the centering base (21). The sleeve (22) is connected to the centering tube (23) through the floating element (25). An inner hole (24) is provided inside the centering tube (23). The axis of the inner hole (24) coincides with the theoretical rotation axis of the tool holder. The inner hole (24) and the cutting diameter of the drill bit installed in the tool holder are separated by a gap. The end of the centering tube (23) contacts the workpiece before the drill bit.

2. The drilling device for high-precision machining according to claim 1, characterized in that, The end face of the centering tube (23) that contacts the workpiece is an arc-shaped surface.

3. The drilling device for high-precision machining according to claim 1, characterized in that, The thickness of the floating component (25) is between 0.1 mm and 0.5 mm.

4. The drilling device for high-precision machining according to claim 1, characterized in that, The ratio of the length of the inner hole (24) to the cutting diameter of the drill bit is between 1.5 and 3.

0.

5. The drilling device for high-precision machining according to claim 1, characterized in that, The drilling machine (10) also includes a support (11), a motor (12) and a rotating shaft (13). The support (11) is arranged on the processing table, the motor (12) is installed on the support (11), and the rotating shaft (13) is coupled inside the support (11). The rotating shaft (13) is connected to the output shaft of the motor (12) through a transmission device.

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