Machining method of micro-texture internal cooling drill bit for high-temperature alloy machining

Abstract

The invention relates to the field of ultrafast laser surface treatment, in particular to a machining method of a micro-texture internal cooling drill bit for high-temperature alloy machining. A high-power and short-pulse ultrafast laser is adopted for carrying out surface treatment on the cutter, and hyperfine and low-damage high-quality precision machining is achieved; by means of the five-axis linkage design, multi-angle and all-directional laser texturing machining of the spiral groove and the auxiliary rear tool face can be achieved; the composite texture of the spiral groove improves the chip removal capacity and reduces cutting backflow; the supporting strength and vibration reduction performance of the rear tool face are enhanced through the first rear tool face convex body texture, micro lubricating points are formed, and frictional wear is reduced; the precision of drilling, guiding and positioning is improved through the auxiliary rear tool face convex body texture, and the forming quality of the hole wall surface is improved; the front cutter face groove texture is used for guiding cutting flow and has the functions of containing and discharging chips, storing oil for lubrication and forming the dynamic pressure effect.

Description

Technical Field

[0001] The present invention relates to the field of ultrafast laser surface treatment, and particularly to a processing method for a micro-textured internal cooling drill bit for superalloy machining. Background Art

[0002] Due to its excellent high-temperature performance, mechanical properties, and chemical stability, superalloys have been widely used in the fields of aerospace, energy and chemical engineering, and automotive manufacturing. During the machining process, superalloy materials generally have poor thermal conductivity, large hardness and deformation tendency, and high surface forming quality requirements, which bring great difficulties to cutting and drilling operations. The internal cooling twist drill bit is one of the important tools for superalloy machining. By injecting coolant through the built-in through-hole structure, the temperature of the workpiece and the tool can be effectively reduced, the chip evacuation can be accelerated, and the machining accuracy and the surface finish of the cutting can be improved. During the drilling process, the tool faces complex working conditions of high temperature, high pressure, high speed, and heavy load. Insufficient surface performance will not only accelerate wear and chip accumulation, but also cause the drill bit temperature to rise, the cutting force to increase, and faults such as breakage and chipping, seriously affecting the working efficiency, machining accuracy, and service life of the tool. Common solutions improve the wear-resistant and friction-reducing performance of the drill bit through surface treatment processes such as electroplating, spraying, chemical vapor deposition, and laser texturing. Among them, laser texturing uses a high-energy laser beam to rapidly heat the material to locally melt and vaporize, thereby ablating a certain pattern or microstructure, which has the advantages of high precision, high efficiency, non-contact, and high flexibility.

[0003] At present, the research on laser texturing of tools mostly focuses on surface treatment of the front and back tool faces. As the chip evacuation channel and the guiding and finishing structure, the surface performance of the spiral groove and the secondary flank directly affects the service life of the tool and the surface roughness of the hole wall. However, their structures and angles are complex, making it difficult to achieve efficient machining of the surface. In addition, existing processing equipment mostly uses nanosecond and microsecond lasers, and there is still room for improvement in machining accuracy and quality. Finding a convenient and effective drill bit surface texturing process is an inescapable responsibility and obligation for scientific researchers.

[0004] Compared with traditional lasers, ultrafast lasers have a larger peak power, and the pulse width is in the femtosecond to picosecond range. They have higher precision and spatial resolution than ordinary lasers, effectively avoiding energy transfer, conversion, and heat diffusion, and can achieve machining accuracy at the micron or even nanometer level, which is beneficial for machining high-hardness, high-brittle, and high-melting-point materials. In addition, ultrafast lasers do not produce defects such as molten regions, recast layers, and microcracks during the machining process, showing good application prospects in tool surface treatment. Summary of the Invention

[0005] In order to improve the cutting performance of drill tools and increase their service life and drilling quality, the present invention proposes an ultrafast laser texturing method for five-axis linkage processing of the drill surface, and by preparing three different micro-nano textures on the rake face, flank face, secondary flank face and spiral groove, the drill has better chip removal, chip holding, friction reduction and lubrication capabilities, so as to extend the service life of the tool.

[0006] The present invention discloses a processing method for a micro-textured internally cooled drill bit for high-temperature alloy processing, wherein the drill bit rake face is subjected to groove continuous laser texturing processing; the first flank face and the secondary flank face are subjected to convex discrete laser texturing processing; and the spiral groove is subjected to groove / convex composite laser texturing processing. The groove texture is used to guide chip flow, store oil, reduce friction and hold chips, and form a dynamic pressure effect at the same time. The convex texture is used to reduce vibration, reduce friction and support, and prevent chip reflux at the same time. The drill bit surface texture is processed by a five-axis linkage ultrafast laser processing equipment, which can realize all-round, multi-angle, high-efficiency and high-quality surface processing in one clamping. Compared with other tool surface treatment technologies, the present invention improves the tool tribological performance and chip removal ability by designing textures of different sizes and morphologies on the rake face, the first flank face, the secondary flank face and the spiral groove, respectively, and provides a new method for the surface treatment of drill bit cutting tools.

[0007] The present invention relates to a processing method for a micro-textured internally cooled drill bit for high-temperature alloy processing. The surface of the drill bit is textured by an ultrafast laser with five-axis linkage and one-time clamping. Three textures with different morphologies are processed on the front cutting edge, the back cutting edge and the spiral groove of the twist drill respectively to improve the wear resistance, friction reduction and chip removal capabilities of the tool, extend the service life of the tool, and improve the processing accuracy and cutting quality. The core technical methods of the process improvement mainly include three aspects:

[0008] First, the rake face adopts a rectangular groove texture to reduce the contact area with the cutting tool and facilitate chip removal. The embedded cutting fluid will also reduce the degree of wear and cutting force to a certain extent.

[0009] Secondly, the first back tool face and the secondary back tool face adopt a circular convex structure to improve its support and vibration reduction performance. A lubricating film will be formed between the convex body and the workpiece being processed during the processing, further increasing its wear resistance and friction reduction performance.

[0010] Third, the spiral groove adopts a composite structure of rectangular grooves and circular convex bodies. During the cutting process, the grooves can effectively guide the cutting flow, and the convex bodies can prevent the cutting backflow.

[0011] The processing device of this invention includes a five-axis linkage ultrafast laser and a fixture. This invention can achieve one-time clamping of the tool and all-round processing, improving work efficiency and realizing surface texturing treatment with multiple angles and structures; it improves problems such as poor forming quality caused by traditional laser processing of the rake face and flank face of the tool; it enables rapid chip discharge, improves the burnishing ability and positioning accuracy of drilling, and reduces the cutting force and wear degree during the processing.

[0012] According to one aspect of this application, a processing method for a micro-textured internal cooling drill bit for superalloy processing is provided, including the following steps:

[0013] (1) Fix the position of the drill bit;

[0014] (2) Conduct groove continuous laser texturing processing on the rake face of the drill bit;

[0015] (3) Conduct convex body discrete laser texturing processing on the first flank face and the secondary flank face of the drill bit;

[0016] (4) Conduct groove / convex body composite laser texturing processing on the spiral groove of the drill bit to obtain the micro-textured internal cooling drill bit for superalloy processing.

[0017] The groove texture is used to guide chip flow, store oil, store chips and reduce friction, and at the same time form a hydrodynamic effect. The convex body texture is used for vibration reduction, support and friction reduction, and at the same time prevents chip backflow.

[0018] The cross-sectional shape of the groove in the groove continuous laser texturing processing is rectangular, with a depth of 50 - 100 nm, a width of 100 - 200 nm, distributed in a straight line, and the center lines of each groove are spaced 100 - 1000 nm apart, all at an angle of 0 - 90° with the main cutting edge; the texture area on the rake face is rectangular, with a length of 2 - 10 mm and a width of 1 - 5 mm, and the long side of the rectangle is parallel to the main cutting edge.

[0019] The convex body in the convex body discrete laser texturing processing is cylindrical, with a diameter of 50 - 100 nm and a height of 50 - 100 nm. The geometric centers of the convex bodies are spaced 200 - 400 nm apart, distributed in a periodic regular pattern; the texture processing areas on the first flank face and the secondary flank face are rectangular, with a length of 2 - 10 mm and a width of 1 - 5 mm, and the long side of the rectangle is parallel to the main cutting edge.

[0020] The cross-sectional shape of the groove in the groove / convex body composite laser texturing process is rectangular, with a distance of 1-3 mm from the rake face texture, a depth of 50-100 nm, a width of 100-200 nm, and is distributed in a spiral shape along the spiral direction. The distance between the centerlines of each groove is 100-200 nm; inside, cylindrical convex bodies with a diameter of 50-100 nm and a height of 50-100 nm are distributed, and the geometric centers of the convex bodies are spaced 100-500 nm and are distributed along the centerline of the groove.

[0021] Processing is carried out using a five-axis linkage ultrafast laser processing equipment.

[0022] The five-axis linkage ultrafast laser processing equipment consists of two parts: a laser and a fixture;

[0023] The fixture is equipped with a base, a three-jaw self-centering chuck and a collet chuck, and can rotate freely along the A and C axes. The field lens / scanning galvanometer can move freely along the X, Y, and Z axes. The axes are connected by a precision transmission mechanism and are equipped with a servo motor or other high-precision drive devices to achieve five-axis linkage control and complete complex three-dimensional space motions and processing tasks.

[0024] The fixed drill bit position includes adjusting the three-jaw self-centering chuck to make the collet chuck coaxial with the three-jaw self-centering chuck, and fixing the drill bit in the three-jaw self-centering chuck to achieve the fixation of the drill bit position.

[0025] The drill bit is an M6 high-speed steel drill bit or an HRC65 ultra-hard tungsten steel drill bit.

[0026] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0027] 1. Using a high-power, short-pulse ultrafast laser to perform surface treatment on the tool, realizing ultra-fine, low-damage high-quality precision machining;

[0028] 2. Through the five-axis linkage design, laser texturing processing of spiral grooves and the secondary flank face can be realized from multiple angles and in all directions;

[0029] 3. The composite texture of the spiral groove improves the chip evacuation ability and reduces cutting backflow;

[0030] 4. The convex body texture on the first flank face strengthens the support strength and vibration damping of the flank face, forms micro-lubrication points, and reduces friction and wear;

[0031] 5. The convex body texture on the secondary flank face increases the accuracy of drilling, guiding and positioning, and improves the surface forming quality of the hole wall;

[0032] 6. The groove texture on the rake face is used to guide the cutting flow, play the role of chip evacuation, oil storage and lubrication, and form a hydrodynamic effect.

[0033] The present invention provides a general low-cost method for continuous and discrete surface texturing of cutting tools, which can achieve all-round fine and efficient machining of the drill bit surface. Description of the Drawings

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly describe the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only a part of the embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0035] Figure 1 It is a front view structural schematic diagram of the drill bit before processing in Embodiment 1;

[0036] Figure 2 It is a partial enlarged schematic diagram of the rake face micro-nano texture in Embodiment 1;

[0037] Figure 3 It is a partial enlarged schematic diagram of the first flank face micro-nano texture in Embodiment 1;

[0038] Figure 4 It is a partial enlarged schematic diagram of the secondary flank face and spiral groove micro-nano texture in Embodiment 1;

[0039] Figure 5 It is a schematic diagram of the processing process in Embodiment 1;

[0040] Among them: 11 cooling holes, 21 main cutting edge, 22 rake face, 31 chisel edge, 32 first flank face, 33 second flank face, 41 secondary flank face, 42 spiral groove, 51 field lens / galvanometer, 52 three-jaw self-centering chuck, 521 center drill, 53 base. Detailed Embodiments

[0041] The surface of the drill bit is processed by a five-axis linkage ultrafast laser processing equipment. First, the coaxiality of the spring collet and the chuck is achieved by adjusting the three-jaw self-centering chuck, and the drill bit is fixed in the collet, and the surface of the drill bit is processed by the ultrafast laser processing equipment; secondly, continuous laser texturing processing of grooves is carried out on the rake face; thirdly, discrete laser texturing processing of convex bodies is carried out on the first flank face and the secondary flank face; finally, groove / convex body composite laser texturing processing is carried out on the spiral groove. The five-axis linkage equipment can realize all-round and multi-angle machining of the drill bit in one clamping. The groove texture is used to guide chip flow, store oil, store chips and reduce friction, and at the same time form a hydrodynamic effect. The convex body texture is used for vibration damping, support and friction reduction, and at the same time prevent chip backflow.

[0042] The specific embodiments are as follows:

[0043] Embodiment 1:

[0044] The surface texturing of an M6 high-speed steel drill bit (diameter 6.6 mm, cutting edge length 53 mm, overall length 90 mm) is carried out using a five-axis linkage ultra-fast laser processing equipment. The tests are conducted using the said test equipment and process, including the following steps:

[0045] Step 1. Fix the fixture along the x-axis or y-axis direction, adjust the a-axis of the fixture so that the three-jaw self-centering chuck is in a horizontal position. Place the collet chuck into the chuck, adjust the thimble so that the three-jaw chuck and the collet chuck are coaxial, and fix the drill bit in the chuck.

[0046] Step 2. Adjust the a-axis and c-axis so that the first flank face is in a horizontal position.

[0047] Step 3. Turn on the laser processing system. The focal length of the used field lens is 400 mm, and the depth of focus is 200 μm. Measure the distance between the flank face and the field lens using a laser rangefinder. By controlling the z-direction displacement platform, adjust the position of the galvanometer / field lens so that the distance from the galvanometer / field lens to the flank face is equal to the focal length of the field lens, 400 mm. By controlling the x- and y-direction displacement platforms, move the initial machining position of the flank face to the origin position of the CCD camera target.

[0048] Step 4. On the basis of the state described in Step 3, set the machining area as a 2×3 mm rectangle. The rectangle is located in the middle of the first flank face, with the long side parallel to the main cutting edge. The inside is composed of circular convex bodies with a diameter of 100 nm and a height of 50 nm. The centers of the convex bodies are all located at the nodes of a 200×200 nm square grid, and run the machining program.

[0049] Step 5. Rotate the c-axis by 180°, and repeat Step 4.

[0050] Step 6. Adjust the a-axis and c-axis so that the secondary flank face is in a horizontal position.

[0051] Step 7. By controlling the z-direction displacement platform, adjust the position of the galvanometer / field lens so that the distance from the galvanometer / field lens to the secondary flank face is equal to the focal length of the field lens, 400 mm. By controlling the x- and y-direction displacement platforms, move the initial machining position of the secondary flank face to the origin position of the CCD camera target.

[0052] Step 8. On the basis of the state described in Step 7, set the machining area as a 0.5×2 mm rectangle. The long side of the rectangle is parallel to the secondary flank face. The inside is composed of circular convex bodies with a diameter of 100 nm and a height of 50 nm. The centers of the convex bodies are all located at the nodes of a 200×200 nm square grid and run the machining program.

[0053] Step 9. Rotate the c-axis by 180°, and repeat Step 8.

[0054] Step 10. By controlling the z-direction displacement platform, adjust the position of the galvanometer mirror / field lens so that the distance from the galvanometer mirror / field lens to the rake face is equal to the focal length of the field lens, which is 400 mm; by controlling the x- and y-direction displacement platforms, move the initial machining position on the rake face to the origin position of the CCD camera target.

[0055] Step 11. On the basis of the state described in Step 10, set the machining area as a 2×3 mm rectangle, with the long side of the rectangle parallel to the main cutting edge. The inside is composed of linear grooves with a depth of 50 nm and a width of 100 nm. The groove spacing is 200 nm, and the direction is parallel to the main cutting edge. Run the machining program.

[0056] Step 12. Rotate the c-axis by 180°, and repeat Step 11.

[0057] Step 13. Adjust the a- and c-axes so that the machining plane at a position 1 mm away from the rake face texture of a spiral groove is in a horizontal position.

[0058] Step 14. By controlling the z-direction displacement platform, adjust the position of the galvanometer mirror / field lens so that the distance from the galvanometer mirror / field lens to the machining plane of the spiral groove is equal to the focal length of the field lens, which is 400 mm; by controlling the x- and y-direction displacement platforms, move the initial machining position of the spiral groove to the origin position of the CCD camera target.

[0059] Step 15. On the basis of the state described in Step 14, set the machining area as a 1×5 mm rectangle, with the short side of the rectangle parallel to the secondary flank. The inside is composed of linear grooves with a depth of 50 nm and a width of 100 nm. The center line spacing of the grooves is 200 nm, and the direction is parallel to the spiral. Inside the grooves, circular convex bodies with a diameter of 50 nm and a height of 50 nm are distributed along the center line, and the geometric centers of the convex bodies are spaced 75 nm apart.

[0060] Step 16. Input commands in the software to control the servo motor to drive the c-axis to rotate counterclockwise at a speed of ~20° / min, and the galvanometer mirror to move along the positive y-axis direction at a speed of 1 mm / s, so that the machining area is filled with spiral grooves along the spiral direction.

[0061] Step 17. Repeat Steps 13 - 16 until the machining of the entire spiral groove texture is completed.

[0062] Step 18. Rotate the c-axis by 180°, and repeat Steps 15 - 17.

[0063] Example 2:

[0064] Use a five-axis linkage ultra-fast laser processing equipment to perform surface texturing on an HRC65 super-hard tungsten steel drill bit (diameter 4 mm, edge length 25 mm, total length 50 mm), and conduct experiments using the described test device and process, including the following steps:

[0065] Step 1. Fix the fixture along the x-axis or y-axis direction, adjust the a-axis of the fixture so that the three-jaw self-centering chuck is in a horizontal position, place the collet chuck into the chuck, adjust the thimble so that the three-jaw chuck and the collet chuck are coaxial, and fix the drill bit in the chuck.

[0066] Step 2. Adjust the a-axis and c-axis so that the first flank face is in a horizontal position.

[0067] Step 3. Turn on the laser processing system. The focal length of the used field lens is 400 mm and the depth of focus is 200 μm. Measure the distance between the flank face and the field lens using a laser rangefinder. Adjust the position of the galvanometer / field lens by controlling the z-direction displacement platform so that the distance from the galvanometer / field lens to the flank face is equal to the focal length of the field lens, 400 mm; move the initial machining position of the flank face to the origin position of the CCD camera target by controlling the x- and y-direction displacement platforms.

[0068] Step 4. On the basis of the state described in Step 3, set the machining area as a rectangle of 1×2 mm. The rectangle is located in the middle of the first flank face, with the long side parallel to the main cutting edge. The inside is composed of circular convex bodies with a diameter of 100 nm and a height of 50 nm. The centers of the convex bodies are all located at the nodes of a 200×200 nm square grid, and run the machining program.

[0069] Step 5. Rotate the c-axis by 180°, and repeat Step 4.

[0070] Step 6. Adjust the a-axis and c-axis so that the secondary flank face is in a horizontal position.

[0071] Step 7. Adjust the position of the galvanometer / field lens by controlling the z-direction displacement platform so that the distance from the galvanometer / field lens to the secondary flank face is equal to the focal length of the field lens, 400 mm; move the initial machining position of the secondary flank face to the origin position of the CCD camera target by controlling the x- and y-direction displacement platforms.

[0072] Step 8. On the basis of the state described in Step 7, set the machining area as a rectangle of 0.2×1 mm. The long side of the rectangle is parallel to the secondary flank face. The inside is composed of circular convex bodies with a diameter of 100 nm and a height of 50 nm. The centers of the convex bodies are all located at the nodes of a 200×200 nm square grid and run the machining program.

[0073] Step 9. Rotate the c-axis by 180°, and repeat Step 8.

[0074] Step 10. Adjust the position of the galvanometer / field lens by controlling the z-direction displacement platform so that the distance from the galvanometer / field lens to the rake face is equal to the focal length of the field lens, 400 mm; move the initial machining position of the rake face to the origin position of the CCD camera target by controlling the x- and y-direction displacement platforms.

[0075] Step 11. On the basis of the state described in Step 10, set the machining area as a rectangle of 1×2 mm, with the long side of the rectangle parallel to the main cutting edge. The inside is composed of linear grooves with a depth of 50 nm and a width of 100 nm. The groove spacing is 200 nm, and the direction is parallel to the main cutting edge. Run the machining program.

[0076] Step 12. Rotate the c-axis by 180°, and repeat Step 11.

[0077] Step 13. Adjust the a-axis and c-axis so that the plane to be machined at a position 0.5 mm away from the texture on the rake face of a helical groove is in a horizontal position.

[0078] Step 14. By controlling the z-direction displacement platform, adjust the position of the galvanometer / field lens so that the distance from the galvanometer / field lens to the plane to be machined of the helical groove is equal to the focal length of the field lens, which is 400 mm. By controlling the x- and y-direction displacement platforms, move the initial position to be machined of the helical groove to the origin position of the CCD camera target.

[0079] Step 15. On the basis of the state described in Step 14, set the machining area as a rectangle of 0.5×3 mm, with the short side of the rectangle parallel to the secondary flank. The inside is composed of linear grooves with a depth of 50 nm and a width of 100 nm. The center line spacing of the grooves is 200 nm, and the direction is parallel to the helix. Inside the grooves, circular convex bodies with a diameter of 50 nm and a height of 50 nm are distributed along the center line, and the geometric centers of the convex bodies are spaced 75 nm apart.

[0080] Step 16. Input instructions in the software to control the servo motor to drive the c-axis to rotate counterclockwise at a speed of ~40° / min, and the galvanometer moves along the positive y-axis at a speed of 0.5 mm / s, so that the machining area is covered with helical grooves along the helix direction.

[0081] Step 17. Repeat Steps 13 to 16 until the machining of the entire helical groove texture is completed.

[0082] Step 18. Rotate the c-axis by 180°, and repeat Steps 15 to 17.

[0083] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can make several deformations or substitutions, which should all be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A method for processing a micro-textured internally cooled drill bit for processing high-temperature alloys, characterized in that: The following steps are involved: (1) Fix the drill bit position; (2) Performing groove continuous laser texturing on the rake face of the drill bit; (3) performing convex discrete laser texturing processing on the first flank surface and the secondary flank surface of the drill bit; (4) The spiral groove of the drill bit is subjected to groove / convex composite laser texturing processing to obtain the micro-textured internal cooling drill bit for high-temperature alloy processing.

2. The processing method according to claim 1, characterized in that: The groove cross-section shape of the groove continuous laser texturing process is rectangular, the depth is 50-100nm, the width is 100-200nm, and it is distributed in a linear manner. The center lines of each groove are spaced 100-1000nm apart, and all form an angle of 0-90° with the main cutting edge; the texture area on the front cutting edge is rectangular, the length is 2-10mm, the width is 1-5mm, and the long side of the rectangle is parallel to the main cutting edge.

3. The processing method according to claim 1, characterized in that: The convex bodies processed by the discrete laser texturing are cylindrical, with a diameter of 50 to 100 nm and a height of 50 to 100 nm. The geometric centers of the convex bodies are spaced 200 to 400 nm apart and are regularly distributed periodically. The texture processing areas of the first back tool face and the secondary back tool face are rectangular, with a length of 2 to 10 mm and a width of 1 to 5 mm, and the long side of the rectangle is parallel to the main cutting edge.

4. The processing method according to claim 1, characterized in that: The groove cross-section of the groove / convex body composite laser texturing process is rectangular, with a distance of 1 to 3 mm from the texture of the front cutting edge, a depth of 50 to 100 nm, a width of 100 to 200 nm, and a spiral distribution along the spiral line direction. The spacing between the center lines of each groove is 100 to 200 nm; cylindrical convex bodies with a diameter of 50 to 100 nm and a height of 50 to 100 nm are distributed inside, and the geometric centers of the convex bodies are spaced 100 to 500 nm apart and distributed along the center line of the groove.

5. The processing method according to claim 1, characterized in that: Five-axis linkage ultrafast laser processing equipment is used for processing.

6. The processing method according to claim 5, characterized in that: The five-axis linkage ultrafast laser processing equipment consists of two parts: a laser and a fixture; The fixture is equipped with a base, a three-jaw self-centering chuck and a spring collet. It can rotate freely along the A and C axes, and the field mirror / galvanometer can move freely along the X, Y and Z axes. The axes are connected by a precision transmission mechanism and are equipped with a servo motor or other high-precision drive device to achieve five-axis linkage control and complete complex three-dimensional space motion and processing tasks.

7. The processing method according to claim 6, characterized in that: The method of fixing the drill bit position includes adjusting the three-jaw self-centering chuck to make the spring chuck coaxial with the three-jaw self-centering chuck, fixing the drill bit in the three-jaw self-centering chuck, and fixing the drill bit position.

8. The processing method according to claim 1, characterized in that: The drill bit is an M6 high-speed steel drill bit or an HRC65 super-hard tungsten steel drill bit.

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