A micro drill bit and a processing apparatus

Abstract

The application relates to the technical field of drilling processing, and discloses a micro drill bit and a processing device. The micro drill bit comprises a drill tip, a drill body and a drill handle which are sequentially connected from front to back along the axial direction of the micro drill bit; a transition part is connected between the drill handle and the drill body; a supercooling channel is arranged in the drill handle, one end of the supercooling channel extends to the transition part, the outer peripheral wall of the transition part is provided with a first jet hole which is in communication with the supercooling channel and is open to the drill tip, and the supercooling channel is adapted to be in communication with an external cold source, and the first jet hole is open to the drill tip. In this way, the first jet hole can obtain cooling medium from the external cold source and spray the cooling medium to the drill tip by arranging the first jet hole on the transition part, the cooling medium can cool the drill tip to reduce the temperature of the drill tip, compared with the prior art, the temperature rising speed of the drill bit can be slowed down, the wear speed of the micro drill bit can be reduced, the processing quality of a hole structure can be improved, and the service life of the micro drill bit can be prolonged.

Description

Technical Field

[0001] This application relates to the field of drilling technology, and in particular to a micro drill bit and a processing device having the micro drill bit. Background Technology

[0002] In related technologies, drill bits cut material on the surface of a workpiece to form a hole structure. Micro drill bits can be used to process hole structures with tiny diameters (e.g., hole diameters of 0.1mm to 1.0mm), and therefore are widely used in the semiconductor industry. Semiconductors require high-quality hole processing, and the materials used are powder-cast materials such as monocrystalline silicon or polycrystalline silicon. When drilling semiconductor products at high speed, the small hole size created by micro drill bits makes it difficult for the heat generated during processing to dissipate quickly, leading to excessively high drill tip temperatures. This causes rapid wear of the micro drill bit, resulting in deformation and chipping of the processed hole structure, and also affects the lifespan of the micro drill bit. Utility Model Content

[0003] The purpose of this application is to reduce the drill tip temperature, slow down the rate of drill bit heating, thereby slowing down the wear rate of the micro drill bit, improving the machining quality of the hole structure, and extending the service life of the micro drill bit.

[0004] To achieve the above objectives, this application provides a miniature drill bit.

[0005] This application further provides a processing device.

[0006] The micro drill bit according to this application includes: a drill tip, a drill body, and a drill shank connected sequentially from front to back along the axial direction of the micro drill bit; the outer peripheral wall of the drill body is provided with a chip removal groove, the chip removal groove extending from the drill tip to the drill shank; a transition portion is connected between the drill shank and the drill body, the contour line of the outer peripheral wall of the transition portion smoothly transitions from the drill shank to the drill body; a supercooling channel is provided inside the drill shank, one end of the supercooling channel extends to the transition portion, the outer peripheral wall of the transition portion is provided with a first jet hole, the first jet hole communicating with the supercooling channel, and the first jet hole being open towards the drill tip; the first jet hole and... The included angle between the central axes of the micro drill bit is α. In the cross-section of the drill shank, an auxiliary circle is constructed with the axis of the drill shank as the center and the distance from the axis of the inlet end of the first jet hole to the axis of the drill shank as the radius. The diameter of the auxiliary circle is Tk. The total length of the drill body and the drill tip is L1. The diameter of the drill body is D. The diameter of the drill shank is Ds. A conical surface is constructed with the straight line connecting the outer peripheral wall of the front end of the drill shank to the outer peripheral wall of the rear end of the drill body as the contour line. The cone angle of the conical surface is β, and the angle coefficient is δ. δ, α, Tk, L1, D, Ds, and β satisfy the following relationship: 0.75≤δ≤0.95.

[0007] According to the present application, the micro drill bit has a first jet hole on the transition section. The first jet hole can obtain a cooling medium from an external cold source and spray the cooling medium onto the drill tip. The cooling medium can cool the drill tip to reduce the drill tip temperature. Compared with the prior art, it can slow down the temperature rise rate of the drill bit, thereby reducing the wear rate of the micro drill bit, improving the processing quality of the hole structure, and extending the service life of the micro drill bit.

[0008] In some examples of this application, the outer peripheral wall of the transition portion is provided with a plurality of first jet holes, and the plurality of first jet holes are arranged sequentially along the circumference of the transition portion.

[0009] In some examples of this application, the drill shank is provided with a plurality of supercooling channels, which are arranged sequentially at intervals along the circumference of the drill shank, and each supercooling channel is connected to at least one of the first jet holes.

[0010] In some examples of this application, the radial dimension of the supercooling channel is d, and Tk, d and Ds satisfy the following relationship: Tk = 0.68Ds - 0.554, 0.08Ds ≤ d ≤ 0.7Ds.

[0011] In some examples of this application, the drill tip is provided with a chisel edge and a main cutting edge at the end away from the drill body. The main cutting edge is connected between the chisel edge and the chip removal groove. The main cutting edge includes one or more sub-cutting edges. In the main cutting edge having multiple sub-cutting edges, the multiple sub-cutting edges are connected in sequence, and there is an included angle between any two adjacent sub-cutting edges of each main cutting edge.

[0012] In some examples of this application, the drill tip has a plurality of said main cutting edges to pass through the central axis of the micro drill bit and to construct a mid-section parallel to two adjacent said main cutting edges, each said main cutting edge including a said sub-cutting edge, and in the same mid-section, the included angle between the projections of two adjacent said main cutting edges in the corresponding mid-section is θ, θ satisfying the relationship: 110°≤θ≤160°.

[0013] In some examples of this application, the drill tip has a plurality of main cutting edges that pass through the central axis of the micro drill bit and are parallel to two adjacent main cutting edges to form a mid-section. Each main cutting edge includes a first sub-cutting edge, a second sub-cutting edge, and a third sub-cutting edge connected sequentially from the drill tip to the drill body. The first sub-cutting edge is connected to the chisel edge. Within the same mid-section, the angle between the projections of two adjacent first sub-cutting edges in the corresponding mid-section is θ1, the angle between the projections of two adjacent second sub-cutting edges in the corresponding mid-section is θ2, and the angle between the projections of two adjacent third sub-cutting edges in the corresponding mid-section is θ3. A first proportionality coefficient is K1, and θ1, θ2, θ3, and K1 satisfy the following relationships: 110°≤θ1≤160°, θ2=-0.1θ1 2 +27θ1-1730,θ3=K1*(-0.05θ1 2 +13.5θ1-850), 0.4≤K1≤1, θ2>θ3.

[0014] In some examples of this application, the drill tip has a plurality of main cutting edges that pass through the central axis of the micro drill bit and are parallel to two adjacent main cutting edges to form a mid-section. Each main cutting edge includes a first sub-cutting edge, a second sub-cutting edge, and a third sub-cutting edge connected sequentially from the drill tip to the drill body. The first sub-cutting edge is connected to the chisel edge. Within the same mid-section, the angle between the projections of two adjacent first sub-cutting edges in the corresponding mid-section is θ1, the angle between the projections of two adjacent second sub-cutting edges in the corresponding mid-section is θ2, and the angle between the projections of two adjacent third sub-cutting edges in the corresponding mid-section is θ3. The second proportionality coefficient is K2, and θ1, θ2, θ3, and K2 satisfy the following relationships: 110°≤θ1≤160°, θ2=-0.144θ12 +38.88θ1-2504.4,θ3=K2*(-0.096θ1 2 +25.92θ1-1659.6), 1≤K2≤1.5, θ2<θ3.

[0015] In some examples of this application, the diameter of the drill body is D, and the distance between the end of the first sub-cutting edge away from the central axis of the micro drill bit and the central axis of the micro drill bit is R. 1a The distance R between the end of the second sub-cutting edge furthest from the central axis of the micro drill bit and the central axis of the micro drill bit. 2a The distance between the end of the third sub-cutting edge furthest from the central axis of the micro drill bit and the central axis of the micro drill bit is R. 3a R 1a R 2a and R 3a Satisfies the relation: 0.2D≤R 1a ≤0.325D, 0.325D<R 2a ≤0.425D, R 3a =0.5D.

[0016] In some examples of this application, the drill tip further includes a main relief face, which is located behind the main cutting edge, and the tangential surface of the main cutting edge forms a relief angle φ with the main relief face. In the direction from the transverse cutting edge to the chip groove, the first sub-cutting edge has two relief angles, and the second and third sub-cutting edges each have one relief angle. The relief angle φ of the first sub-cutting edge is located near the relief face of the first sub-cutting edge. 11 The range is 1°-20°, and the clearance angle φ of the first sub-cutting edge away from the flank face of the first sub-cutting edge is... 12 The range is 10°-50°, and φ 11 <φ 12 The clearance angle φ2 of the second sub-cutting edge ranges from 10° to 50°; the clearance angle φ3 of the third sub-cutting edge ranges from 10° to 50°.

[0017] In some examples of this application, the flank face of the first sub-cutting edge is provided with a second cutting edge, and a chamfered surface is connected between the first sub-cutting edge and the second cutting edge. An auxiliary plane is used with a plane perpendicular to the central axis of the micro drill bit. The included angle between the chamfered surface and the auxiliary plane is the chamfered angle of the chamfered surface. The diameter of the drill body is D, the width of the second cutting edge is Dx, and the size of the chamfered angle is γ. Dx and γ satisfy the following relationship: 0.07D≤Dx≤0.13D, 2°≤γ≤7°.

[0018] In some examples of this application, the main cutting edge includes a plurality of sequentially connected sub-cutting edges, at least two adjacent sub-cutting edges have a transition surface at the connection point of their flank faces, and / or the connection point between the drill tip and the outer periphery of the drill body, the transition surface has a microtexture, and a cutting edge band is provided between the microtexture and the cutting edge of each sub-cutting edge, the microtexture being formed by an array of multiple microgrooves.

[0019] In some examples of this application, the drill body includes a first cutting edge, and the transition surface at the connection between the drill tip and the drill body is provided on the first cutting edge; the transition surface is constructed as an arc transition surface, a transition plane, or an obtuse angle transition surface; the microgroove is a hole-shaped or a groove-shaped structure arranged longitudinally.

[0020] In some examples of this application, the chip removal groove includes an interconnected spiral groove and a straight groove. The spiral groove extends from the drill tip along the axial direction of the drill body away from the drill tip. The sidewall of the spiral groove is provided with a secondary cutting edge. The straight groove is located at the end of the spiral groove away from the drill tip and extends along the axial direction of the drill body away from the drill tip. A first breaking structure is provided in the chip removal groove. The first breaking structure extends from the end of the straight groove away from the drill tip toward the drill tip. The first breaking structure is formed by an array of multiple first breaking grooves. In the axial direction of the micro drill bit, the length of the chip removal groove is L. The distance between the end of the first breaking structure near the drill tip and the drill tip is L2. L and L2 satisfy the relationship: 0.6L≤L2≤0.7L.

[0021] In some examples of this application, the chip removal groove includes a plurality of sub-chip removal grooves connected sequentially along the axial direction of the drill body, and at least two of the sub-chip removal grooves have different groove shapes; the length dimension of the chip removal groove along the axial direction of the micro drill bit is L, the diameter dimension of the drill body is D, the ratio of the length dimension of the chip removal groove to the diameter dimension of the drill body is A, the maximum number of sub-chip removal grooves is positively correlated with the value of the ratio, the maximum number of sub-chip removal grooves is N, and N and A satisfy the relationship: N = A / 5 + 2, where N is an integer and rounded up.

[0022] In some examples of this application, the drill tip is further provided with a main flank face, the main flank face is provided with a second crushing structure, the second crushing structure includes a plurality of second crushing grooves arranged in sequence.

[0023] In some examples of this application, the drill tip is further provided with a main flank face and a chisel edge. The main flank face is provided with a toothed groove that is recessed into the drill shank. The toothed groove communicates with the chip removal groove and extends from the chisel edge to the outer circle of the drill tip. A chamfered surface with a smooth transition is provided between the toothed groove and the flank face of the sub-cutting edge that is furthest from the drill tip.

[0024] The processing equipment according to this application includes a drive device, a clamping device, and the aforementioned micro drill bit, wherein the clamping device clamps the micro drill bit, and the drive device drives the micro drill bit to rotate through the clamping device.

[0025] According to the processing equipment of this application, the processing equipment has a micro drill bit. When the processing equipment uses the micro drill bit to process a workpiece, a first jet hole is provided on the transition part of the micro drill bit. The first jet hole can obtain a cooling medium from an external cold source and spray the cooling medium onto the drill tip. The cooling medium can cool the drill tip to reduce the drill tip temperature. Compared with the prior art, the heating rate of the drill bit can be slowed down, thereby reducing the wear rate of the micro drill bit, improving the processing quality of the hole structure, and extending the service life of the micro drill bit. Attached Figure Description

[0026] Figure 1 This is a front view of a miniature drill bit according to an embodiment of this application;

[0027] Figure 2 This is a side view of a miniature drill bit according to an embodiment of this application having two main cutting edges;

[0028] Figure 3 These are schematic diagrams illustrating three implementations of the transition surface in the embodiments of this application;

[0029] Figure 4 This is a schematic diagram of the arrangement of micro-grooves on the transition surface when the micro-groove structure of this application is a dot-shaped micro-groove.

[0030] Figure 5 This is a schematic diagram of the arrangement of the micro-grooves on the transition surface when the micro-grooves in this embodiment of the application are linear micro-grooves;

[0031] Figure 6 This is a schematic diagram showing the arrangement of micro-grooves on the transition surface when the micro-grooves in this embodiment are planar micro-grooves.

[0032] Figure 7 These are front views of nine embodiments of the transition section in this application.

[0033] Figure 8 This is a front view of a miniature drill bit according to an embodiment of this application, which has multiple subcooling channels and multiple first jet holes;

[0034] Figure 9 yes Figure 8 A magnified view of a portion of the image;

[0035] Figure 10 This is a front view of a miniature drill bit according to an embodiment of this application, which has a supercooling channel and multiple first jet holes;

[0036] Figure 11These are front views of two embodiments of the miniature drill bit according to this application, wherein the miniature drill bit has a supercooling channel and multiple second jet holes, and the second jet holes are located outside the chip removal groove;

[0037] Figure 12 This is a front view of another embodiment of the micro drill bit of this application, which has a supercooling channel and multiple second jet holes, and the second jet holes are located outside the chip removal groove;

[0038] Figure 13 This is a front view of another embodiment of the micro drill bit of this application, which has a supercooling channel and a plurality of second jet holes, and the second jet holes are located outside the chip removal groove;

[0039] Figure 14 yes Figure 13 A magnified view of a portion of the image;

[0040] Figure 15 This is a schematic diagram of the micro drill bit at the main cutting edge according to an embodiment of this application;

[0041] Figure 16 This is a schematic diagram of the back angle of the main cutting edge in an embodiment of this application;

[0042] Figure 17 This is a schematic diagram of the chamfered surface according to an embodiment of this application;

[0043] Figure 18 This is a schematic diagram of the first fragmentation structure according to an embodiment of this application;

[0044] Figure 19 This is a cross-sectional view of the first crushing trough according to an embodiment of this application;

[0045] Figure 20 These are cross-sectional views of seven embodiments of the sub-chip removal groove of this application.

[0046] Figure 21 This is a front view of a plurality of sub-chip removal grooves connected in sequence to form a chip removal groove according to an embodiment of this application;

[0047] Figure 22 This is a side view of a miniature drill bit according to an embodiment of this application having three main cutting edges;

[0048] Figure 23 This is a structural schematic diagram of a miniature drill bit according to an embodiment of this application, showing the angle of the backlash groove on the drill tip;

[0049] Figure 24 This is a structural schematic diagram of a miniature drill bit according to an embodiment of this application, showing the backlash angle and backlash spread angle at the drill tip.

[0050] In the image, 100 represents a miniature drill bit.

[0051] 1. Drill tip; 11. Transition surface; 12. Microtexture; 121. Microgroove; 122. First cutting edge; 13. Chisel edge; 14. Main cutting edge; 141. First sub-cutting edge; 142. Second sub-cutting edge; 143. Third sub-cutting edge; 144. Fourth sub-cutting edge; 15. Main flank face; 151. Backlash; 16. Chamfer face; 17. Clearance angle;

[0052] 2. Drill body; 21. Chip removal groove; 211. Sub-chip removal groove; 22. Second jet hole; 23. Second cutting edge;

[0053] 3. Drill shank; 31. Subcooling channel; 311. Subcooling sub-channel; 32. Auxiliary channel;

[0054] 4. Transition section; 41. First jet hole;

[0055] 5. First crushing structure; 51. First crushing trough; 6. Beveled surface. Detailed Implementation

[0056] The specific embodiments of this application will be described in further detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this application, but are not intended to limit the scope of this application.

[0057] like Figures 1-24 As shown in the figure, this application discloses a micro drill bit 100, which can be installed on a processing equipment such as a drilling machine. Specifically, the processing equipment has a clamping device and a driving device. The clamping device is used to clamp the micro drill bit 100, and the driving device drives the clamping device to rotate the micro drill bit 100 around the central axis of the micro drill bit 100. The micro drill bit 100 can process and form a hole structure on the surface of the workpiece. Specifically, the micro drill bit 100 is used to process a hole structure with a diameter of less than 3.175 mm. For example, the micro drill bit 100 can process and form a hole structure of 0.1 mm to 1.0 mm.

[0058] like Figures 1-24 As shown, the miniature drill bit 100 according to an embodiment of this application includes: a drill tip 1, a drill body 2, and a drill shank 3 connected sequentially from front to back along the axial direction of the miniature drill bit 100. The drill shank 3 is adapted to be connected and cooperated with a clamping device. The clamping device clamps the outer peripheral wall of the drill shank 3. Under the drive of the driving device, the clamping device can drive the drill shank 3 to rotate the drill tip 1 and the drill body 2. The outer peripheral wall of the drill body 2 is provided with a spiral chip removal groove 21. The chip removal groove 21 extends from the drill tip 1 to the drill shank 3. After the drill tip 1 peels the material from the surface of the workpiece, the material chips are discharged out of the hole along the chip removal groove 21, thereby reducing the accumulation of material chips in the hole.

[0059] like Figure 7As shown, a transition section 4 connects the drill shank 3 and the drill body 2. The outline of the outer peripheral wall of the transition section 4 smoothly transitions from the drill shank 3 to the drill body 2, thereby enabling a smooth transition between the drill shank 3 and the drill body 2. Specifically, the transition section 4 can be constructed as a rotating body with the central axis of the micro drill bit 100 as its axis of rotation, and along the axial direction of the micro drill bit 100, the outline of the transition section 4 can be one or more combinations of straight lines and curves. Figure 7 (1)- Figure 7 (9) shows the specific structure of the transition section 4 of the micro drill bit 100 of this application in different embodiments.

[0060] Furthermore, such as Figures 8-13 As shown, a supercooling channel 31 can be provided inside the drill shank 3. One end of the supercooling channel 31 extends to the transition portion 4. A first jet hole 41 can be provided on the outer peripheral wall of the transition portion 4. The first jet hole 41 communicates with the supercooling channel 31 and is open towards the drill tip 1. The supercooling channel 31 is suitable for communication with an external cold source. The external cold source can provide a cooling medium to the supercooling channel 31, and the cooling medium can further flow into the first jet hole 41 and be sprayed onto the drill tip 1 through the outlet of the first jet hole 41 to cool and lubricate the drill tip 1, preventing the drill tip 1 from overheating and causing the micro drill bit 100 to wear too quickly. This can improve the machining quality of the hole structure and extend the service life of the micro drill bit.

[0061] It should be noted that the cooling medium can be either a gas or a liquid. Specifically, when the cooling medium is a gas, it can be air or nitrogen, etc.; when the cooling medium is a liquid, it can be water or coolant, etc. The specific type of cooling medium can be set according to the workpiece being processed by the micro drill bit 100.

[0062] Furthermore, the angle between the first jet hole 41 and the central axis of the micro drill bit 100 is α. In the cross-section of the drill shank 3, an auxiliary circle is constructed with the axis of the drill shank 3 as the center and the distance from the axis of the inlet end of the first jet hole 41 to the axis of the drill shank 3 as the radius. The diameter of the auxiliary circle is Tk. The total length of the drill body 2 and the drill tip 1 is L1. The diameter of the drill body 2 is D. The diameter of the drill shank 3 is Ds. A conical surface is constructed with the straight line connecting the outer peripheral wall of the front end of the drill shank 3 to the outer peripheral wall of the rear end of the drill body 2 as the contour line. The cone angle of the conical surface is β, and the angle coefficient is δ. δ, α, Tk, L1, D, Ds, and β satisfy the following relationship: 0.75≤δ≤0.95.

[0063] The distance Tk from the axis of the inlet end of the first jet orifice 41 to the axis of the drill shank 3 affects the uniformity of the cooling medium distribution. A suitable interval distance Tk can ensure that the cooling medium is evenly distributed within the drill shank 3. The total length L1 of the drill body 2 and the drill tip 1 affects the jetting distance of the cooling medium. If the length L1 is too long, the cooling medium cannot flow to the drill tip 1; if the length L1 is too short, the cooling medium cannot sufficiently cool the drill tip 1. The diameter D of the drill body 2 limits the subcooling area of ​​the subcooling channel 31, thereby affecting the flow rate of the coolant. The cone angle β affects the opening shape of the first jet orifice 41, and thus affects the jetting direction of the first jet orifice 41. The angle coefficient δ can be obtained through multiple experiments. In this application, the value range of the angle coefficient δ is 0.75 to 0.95. The angle coefficient δ is used to reduce the directional deviation of the first jet orifice 41 during actual use, so that the first jet orifice 41 can more accurately jet the cooling medium to the drill tip 1.

[0064] Therefore, in the process of designing the micro drill bit 100, by making the parameters of the micro drill bit 100 satisfy the above relationship, the spray direction of the first jet hole 41 can be designed more reasonably, thereby enabling the drill tip 1 to obtain a good cooling effect.

[0065] Furthermore, the outer wall of the drill shank 3 is provided with an inlet communicating with the subcooling channel 31. The inlet is connected to an external cold source, which can supply cooling medium to the subcooling channel 31 through the inlet. In some specific implementations, such as... Figure 8 , Figures 10-12 As shown, the inlet is located on the end wall of the drill shank 3 away from the drill body 2, and the supercooling channel 31 extends axially along the micro drill bit 100. In other embodiments, the inlet is located on the outer peripheral wall of the drill shank 3, and the supercooling channel 31 extends radially along the micro drill bit 100.

[0066] like Figures 8-10 As shown, in some embodiments of this application, the outer peripheral wall of the transition portion 4 may be provided with a plurality of first jet holes 41, which are arranged sequentially along the circumference of the transition portion 4. All the plurality of first jet holes 41 are connected to the subcooling channel 31, and the cooling medium in the subcooling channel 31 can be diverted to the plurality of first jet holes 41 so that the plurality of first jet holes 41 together provide cooling medium to the drill tip 1.

[0067] Preferably, the plurality of first jet holes 41 can be evenly spaced on the outer peripheral wall of the transition portion 4. By using the plurality of first jet holes 41 to simultaneously provide cooling medium to the drill tip 1, the drill tip 1 can be cooled from multiple directions, which can make the temperature uniform throughout the circumference of the drill tip 1, thereby preventing the drill tip 1 from breaking due to excessive local temperature difference. It should be noted that the shape of the first jet holes 41 can be circular, strip-shaped, square, etc.

[0068] like Figure 8 , Figure 9 As shown, in some other embodiments of this application, a plurality of supercooling channels 31 may be provided inside the drill shank 3. The plurality of supercooling channels 31 are arranged sequentially at intervals along the circumference of the drill shank 3, and each supercooling channel 31 communicates with at least one first jet hole 41. Preferably, in Figure 8 In the embodiment shown, multiple subcooling channels 31 are configured in a one-to-one correspondence with multiple first jet holes 41. That is, each subcooling channel 31 is connected to a first jet hole 41. By controlling the flow rate of the cooling medium in the subcooling channel 31, the amount of cooling medium ejected from the corresponding first jet hole 41 can be controlled, thereby precisely adjusting the cooling effect at various points of the drill tip 1.

[0069] Furthermore, such as Figure 8 , Figure 9 As shown, the diameter of the drill shank 3 is Ds, the radial dimension of the supercooling channel 31 is d, and the distance between any two adjacent supercooling channels 31 is Tk. Tk, d, and Ds satisfy the following relationship: Tk = 0.68Ds - 0.554, 0.08Ds ≤ d ≤ 0.7Ds. It should be noted that the 0.554 mentioned above refers to 0.554 mm.

[0070] When the radial dimension d of the supercooling channel 31 is less than 0.08 times the diameter Ds of the drill shank 3, the flow area of ​​the supercooling channel 31 is too small, resulting in poor performance of the supercooling channel 31 in guiding the cooling medium, which cannot meet the cooling requirements of the micro drill bit 100. When the radial dimension d of the supercooling channel 31 is greater than 0.7 times the diameter Ds of the drill shank 3, the supercooling channel 31 occupies too much space on the drill shank 3, making it difficult to arrange multiple supercooling channels 31 simultaneously on the drill shank 3, thus making it difficult to process the micro drill bit 100. By making the radial dimension d of the supercooling channel 31 satisfy the corresponding relationship, the radial dimension of the supercooling channel 31 can be made as large as possible, allowing for a larger flow rate of the cooling medium within the supercooling channel 31, thereby improving the cooling effect on the drill tip 1.

[0071] like Figure 9 As shown, in some embodiments of this application, in order to reduce the difficulty of machining the first jet hole 41 on the conical surface of the transition portion 4, during the machining of the micro drill bit 100, the first jet hole 41 is extended in the reverse direction along the central axis of the first jet hole 41 so that the first jet hole 41 intersects with the outer peripheral wall of the drill shank 3. Then, a machining equipment is used to machine the jet hole from the intersection point of the first jet hole 41 and the outer peripheral wall of the drill shank 3 to the conical surface of the transition portion 4. Finally, glue or welding metal is used to seal the extension section of the first jet hole 41, thereby making the machining of the first jet hole 41 possible. In some embodiments of this application, the orifice of the extension section can also serve as an inlet.

[0072] like Figure 10 As shown, in some embodiments of this application, when a supercooling channel 31 is provided inside the drill shank 3 and multiple first jet holes 41 are provided, the outer peripheral wall of the drill shank 3 may be provided with at least one auxiliary channel 32 extending radially along the drill shank 3. The auxiliary channel 32 may connect the supercooling channel 31 and at least one first jet hole 41, so that the supercooling channel 31 is simultaneously connected to multiple first jet holes 41. Further, the radial dimension of the auxiliary channel 32 is the same as the radial dimension of the supercooling channel 31, or the radial dimension of the auxiliary channel 32 is the same as the radial dimension of the first jet hole 41.

[0073] It should be noted that, in order to prevent the cooling medium from leaking from the opening of the auxiliary channel 32 on the outer peripheral wall of the drill shank 3, after the auxiliary channel 32 connects to the cooling channel 31 and the corresponding first jet hole 41, the opening of the auxiliary channel 32 on the outer peripheral wall of the drill shank 3 needs to be sealed. The sealing methods for the opening of the auxiliary channel 32 on the outer peripheral wall of the drill shank 3 include, but are not limited to, adhesive sealing, plastic sealing, and welding of additional materials. Figure 2 As shown in some embodiments of this application, the end of the drill tip 1 furthest from the drill body 2 may be provided with a chisel edge 13 and a main cutting edge 14. The chisel edge 13 is used to help center the micro drill bit 100 in the early stages of drilling and also participates in the initial drilling process. The main cutting edge 14 is connected between the chisel edge 13 and the chip flute 21. The main cutting edge 14 is used for the main drilling work, peeling away material from the workpiece to form a hole structure. The specific structure of the main cutting edge 14 will be described in detail below.

[0074] Furthermore, in some embodiments, the main cutting edge 14 includes a plurality of sequentially connected sub-cutting edges. A transition surface 11 may be provided at the junction of at least two adjacent sub-cutting edges, and / or at the junction of the drill tip 1 and the outer periphery of the drill body 2 (i.e., the inflection point of the drill tip 1 and the drill body 2), the transition surface 11 being located on the flank face of the sub-cutting edge. Preferably, a transition surface 11 is provided at the junction of any two adjacent sub-cutting edges. By providing a transition surface 11 at the junction of two adjacent sub-cutting edges, the transition between the two adjacent sub-cutting edges can be smoothed, reducing the drilling resistance at the junction of the two adjacent sub-cutting edges, thereby minimizing the risk of the main cutting edge 14 breaking.

[0075] Furthermore, from the drill tip 1 to the drill body 2, the outer diameter of the drill tip 1 gradually increases. To reduce the rate of change of the outer diameter at the connection between the drill tip 1 and the drill body 2, a transition surface 11 is provided at the connection between the drill tip 1 and the drill body 2. When the micro drill 100 feeds into the workpiece, the transition surface 11 at the connection between the drill tip 1 and the outer periphery of the drill body 2 allows the hole wall formed by the drill tip 1 to smoothly transition to contact with the drill body 2, thereby reducing the rigid impact on the drill body 2, reducing the working resistance of the micro drill 100, and thus improving the stability of the micro drill 100 during operation. In addition, the transition surface 11 can improve the distribution of cutting heat generated during the operation of the micro drill 100, thereby avoiding local overheating of the micro drill 100 and slowing down the heating rate of the micro drill 100. Further, as Figures 4-6 As shown, the transition surface 11 is provided with a microtexture 12, which is formed by an array of multiple microgrooves 121. The microtexture 12 on the transition surface 11 can be formed by laser processing, electrical discharge machining, or chemical etching. By providing the microtexture 12 on the transition surface 11 at the edge of the drill tip 1, and with the multiple microgrooves 121 arranged in a preset direction, when the chips generated by the drill tip 1 come into contact with the transition surface 11, the microtexture 12 can guide the flow of the chips, improving chip accumulation and secondary cutting problems within the hole. Furthermore, the microgrooves 121 are recessed towards the inside of the drill tip 1, reducing the contact area between the drill bit and the chips, thereby reducing the frictional force on the drill tip 1. Compared with existing technologies, this allows the waste chips generated by the micro drill bit 100 to be discharged from the hole in a timely manner, thus slowing down the drill bit's heating rate, reducing the wear rate of the micro drill bit 100, improving the processing quality of the hole structure, and extending the service life of the micro drill bit 100.

[0076] In addition, the micro-groove 121 can store cutting fluid. When the transition surface 11 contacts the workpiece, the cutting fluid in the micro-groove 121 can further reduce the friction between the transition surface 11 and the workpiece, and can also cool the transition surface 11, thereby further slowing down the heating rate of the micro drill bit 100.

[0077] In some specific implementations, the sub-cutting edge furthest from the chisel edge 13 among the multiple sub-cutting edges of each main cutting edge 14 has a cutting edge band between the microtexture 12 and the cutting edge of each sub-cutting edge, which ensures the strength of the cutting edge and the guiding effect of the cutting direction of the cutting edge. When the main cutting edge 14 separates from the formed hole wall, the microtexture 12 can cut off the chips at the separation point, thereby making the separation of the main cutting edge 14 from the hole wall smoother.

[0078] In some embodiments, such as Figure 2 and Figure 3As shown, the drill body 2 includes a first cutting edge 122, which extends along the axial direction of the drill body 2 and is connected to the chip removal groove 21, so that the connection between the first cutting edge 122 and the chip removal groove 21 forms a secondary cutting edge. The transition surface 11 at the connection between the drill tip 1 and the drill body 2 is provided on the first cutting edge 122. Combined with the cutting edge between the microtexture 12 on each transition surface 11 and the cutting edge, when the micro drill 100 drills to form a hole structure, each cutting edge can contact the hole wall, thereby achieving the supporting effect on the micro drill 100, so that the micro drill 100 can perform hole processing more stably.

[0079] like Figure 3 As shown, in some embodiments of this application, the transition surface 11 is constructed as a circular arc transition surface 11, a transition plane, or an obtuse angle transition surface 11. Wherein, Figure 3 (1) The specific structure of the arc transition surface 11 is shown. Figure 3 (2) The specific structure of the transition plane is shown. Figure 3 (3) The specific structure of the obtuse angle transition surface 11 is shown.

[0080] The arc transition surface is an arc surface that protrudes outward from the drill tip 1. From the drill tip 1 to the drill body 2, the arc transition surface can gradually increase the outer diameter of the micro drill bit 100. By constructing the transition surface 11 as an arc transition surface, when the micro drill bit 100 drills to form a hole structure, the arc transition surface can fit the hole wall surface more closely, thereby reducing the machining marks and tool marks of the hole structure, and thus improving the machining accuracy and surface quality of the hole wall surface.

[0081] The transition plane can be formed by chamfering at the connection between the drill tip 1 and the drill body 2. In the direction from the drill body 2 to the drill tip 1, the transition plane is inclined toward the inner side of the micro drill bit 100. By constructing the transition surface 11 as a transition plane, when the micro drill bit 100 drills to form a hole structure, the plane transition surface 11 can effectively avoid the curved surface of the hole wall, thereby reducing the contact area between the micro drill bit 100 and the hole wall, and thus reducing the resistance experienced by the micro drill bit 100 at the transition surface 11.

[0082] By constructing the transition surface 11 as an obtuse-angled transition surface 11, which consists of two planes with an obtuse angle, the included angle of the two planes protrudes outward toward the drill tip 1. One of the two planes connects to the edge of the drill body 2, and the other connects to the drill tip 1. When the micro drill bit 100 drills to form a hole structure, the obtuse-angled transition surface 11's avoidance effect on the hole wall curved surface is between that of the circular arc transition surface 11 and the transition plane. Along the axial direction of the micro drill bit 100, the obtuse-angled transition surface 11 can assist the drill tip 1 in drilling the hole structure. Thus, users can select a suitable construction of the transition surface 11 according to specific application scenarios to meet the processing requirements of the hole structure.

[0083] In some embodiments of this application, the microgrooves 121 are arranged in multiple rows, including both multi-row multi-column and multi-row single-column arrangements. The extension direction from the drill tip 1 to the drill body 2 is the longitudinal direction of the transition surface 11, and the transverse direction of the transition surface 11 is perpendicular to the longitudinal direction of the transition surface 11. The microgrooves 121 are constructed as either hole-shaped microgrooves 121 or strip-shaped microgrooves 121, with the strip-shaped microgrooves 121 extending from the drill tip 1 to the drill body 2. By arranging microgrooves 121 of different shapes on the transition surface 11 in different arrangements, the usage requirements of different types of micro drill bits 100 can be met.

[0084] Specifically, such as Figure 4 As shown, the multiple micro-grooves 121 are arranged in multiple rows and columns, and the micro-grooves 121 are constructed as the aforementioned perforated micro-grooves 121. That is, multiple columns of micro-grooves 121 are arranged in the longitudinal direction of the transition surface 11, and each column of micro-grooves 121 has multiple micro-grooves 121.

[0085] Furthermore, the aperture size of the perforated microgroove 121 in the longitudinal direction of the transition surface 11 is not greater than the spacing between two adjacent perforated microgroove 121 in the longitudinal direction of the transition surface 11, and the aperture size of the perforated microgroove 121 in the transverse direction of the transition surface 11 is not greater than the spacing between two adjacent perforated microgroove 121 in the transverse direction of the transition surface 11.

[0086] By reducing the spacing between two adjacent perforated microgrooves 121 in the longitudinal direction of the transition surface 11, and correspondingly reducing the aperture size of the perforated microgrooves 121 in the longitudinal direction of the transition surface 11, this arrangement allows the transition surface 11 to accommodate a larger number of microgrooves 121 in the longitudinal direction. Correspondingly, by reducing the spacing between two adjacent perforated microgrooves 121 in the transverse direction of the transition surface 11, and correspondingly reducing the aperture size of the perforated microgrooves 121 in the transverse direction of the transition surface 11, this arrangement allows the transition surface 11 to accommodate a larger number of microgrooves 121 in the transverse direction.

[0087] The specific aperture dimensions of the perforated microgrooves 121 in both the horizontal and vertical directions can be set according to the actual application scenario, such as based on the structural dimensions of the micro drill bit 100 and the area of ​​the transition surface 11. Figure 4 (1) Figure 4 As shown in (2), the figure illustrates two specific implementation methods of multiple porous microgrooves 121 arranged in multiple rows and columns, wherein... Figure 4 (1) A schematic diagram of a perforated microgroove 121 disposed on a transition plane. Figure 4 (2) A schematic diagram of the perforated microgroove 121 set on the obtuse angle transition surface.

[0088] In some preferred embodiments, the perforated microgrooves 121 can be arranged on the transition surface 11 with a small area. By constructing the microgrooves 121 as perforated microgrooves 121, the number of microgrooves 121 on the transition surface 11 can be effectively increased. This allows the microgrooves 121 to make full use of the surface space of the transition surface 11, thereby allowing the microtexture 12 to have a larger chip removal space and to better guide the flow of chips. This can improve the chip accumulation and secondary cutting problems in the hole.

[0089] like Figure 5 and Figure 6 As shown, in some other embodiments of this application, the arrangement of the multiple micro-grooves 121 is a single row and multiple columns arrangement, that is, multiple columns of micro-grooves 121 are arranged in the longitudinal direction of the transition surface 11, and each column of micro-grooves 121 has one micro-grooves 121.

[0090] Furthermore, the microgroove 121 is constructed as the strip-shaped microgroove 121 described above. The strip-shaped microgroove 121 extends along the transverse direction of the transition surface 11, that is, the aperture size of the transition surface 11 in the transverse direction is larger than the aperture size in the longitudinal direction.

[0091] At the same time, such as Figure 5 As shown, the aperture size of the strip-shaped microgrooves 121 in the longitudinal direction of the transition surface 11 is no greater than the spacing between two adjacent strip-shaped microgrooves 121 in the longitudinal direction of the transition surface 11. By reducing the spacing between two adjacent strip-shaped microgrooves 121 in the longitudinal direction of the transition surface 11, and correspondingly reducing the aperture size of the strip-shaped microgrooves 121 in the longitudinal direction of the transition surface 11, this arrangement allows the transition surface 11 to accommodate a larger number of microgrooves 121 in the longitudinal direction. The specific aperture size of the strip-shaped microgrooves 121 in the longitudinal direction of the transition surface 11 can be set according to the actual application scenario, such as based on the structural dimensions of the micro drill bit 100 and the area of ​​the transition surface 11. Figure 5 (1) and Figure 5 As shown in (2), the figure illustrates two specific implementations of the strip-shaped microgrooves 121 of the above embodiments arranged in a single row and multiple columns. Figure 5 (1) A schematic diagram of a strip-shaped microgroove 121 disposed on a transition plane. Figure 5 (2) A schematic diagram of the strip-shaped micro-groove 121 set on the obtuse angle transition surface.

[0092] In some preferred embodiments, the strip-shaped microgroove 121 of the above embodiments can be arranged on a transition surface 11 of moderate area. By constructing the microgroove 121 as the strip-shaped microgroove 121 of the above embodiments, the outer peripheral wall of the drill body 2 is provided with a continuous first cutting edge 122. When the strip-shaped microgroove 121 mates with the first cutting edge 122 and the first cutting edge 122 contacts the hole wall of the hole structure, machining marks and tool marks of the hole structure can be reduced. The microtexture 12 on the transition surface 11 at the connection of each sub-cutting edge and the cutting edge between the microtexture 12 and the cutting edge have the same effect, and will not be described in detail here.

[0093] like Figure 6 As shown, in some other embodiments of this application, the aperture size of the strip-shaped microgroove 121 in the longitudinal direction of the transition surface 11 is not greater than the spacing between two adjacent strip-shaped microgrooves 121 in the longitudinal direction of the transition surface 11. That is, the strip-shaped microgroove 121 can have a larger aperture size in the longitudinal direction of the transition surface 11, and each strip-shaped microgroove 121 occupies a larger space on the transition surface 11. The specific aperture size of the strip-shaped microgroove 121 in the longitudinal direction of the transition surface 11 can be set according to the actual application scenario, such as based on the structural dimensions of the micro drill bit 100, the area of ​​the transition surface 11, etc. Figure 6 (1) Figure 6 As shown in (2), the figure illustrates two specific implementations of the strip-shaped microgrooves 121 of the above embodiments arranged in a single row and multiple columns, wherein, Figure 6 (1) A schematic diagram of a strip-shaped microgroove 121 disposed on a transition plane. Figure 6 (2) A schematic diagram of the strip-shaped micro-groove 121 set on the obtuse angle transition surface.

[0094] In some preferred embodiments, the strip-shaped microgroove 121 of the above embodiments can be arranged on a transition surface 11 with a large area. By constructing the microgroove 121 as the strip-shaped microgroove 121 of the above embodiments, the strip-shaped microgroove 121 of the above embodiments has good rigidity and a sufficiently large contact area between the strip-shaped microgroove 121 of the above embodiments and the hole wall. This can reduce the chipping problem of the micro drill 100 during drilling, thereby enabling the micro drill 100 to process materials that are difficult to process, such as those with high hardness and high toughness, and thus improving the product performance of the micro drill 100.

[0095] It should be understood that the terms "small area," "medium area," and "large area" mentioned above represent the relative area size of the transition surface 11, and not its actual area size. Since different sizes of micro-drill bits 100 have different sizes of transition surfaces 11, the type of microgroove 121 can be set according to the actual usage of the micro-drill bit 100. Furthermore, Figures 4-6The arrangement of the microgrooves 121 shown only provides some feasible embodiments of this application, but this application is not limited thereto. The specific arrangement of the microgrooves 121 can be set according to the actual production situation of the micro drill bit 100.

[0096] like Figures 10-14 As shown in some specific embodiments of this application, the supercooling channel 31 is coaxially arranged with the drill shank 3, and one end of the supercooling channel 31 extends into the drill body 2. A second jet hole 22 is provided on the outer peripheral wall of the drill body 2, and the second jet hole 22 communicates with the supercooling channel 31. The supercooling channel 31 is adapted to communicate with an external cold source. After the external cold source provides cooling medium into the supercooling channel 31, the cooling medium can flow out from the second jet hole 22 to the outside of the micro drill bit 100. The second jet hole 22 is open to the outside of the drill body 2, and part of the cooling medium can flow along the drill body 2 to the drill tip 1 to cool the drill tip 1, thereby preventing the drill tip 1 from overheating and accelerating wear. In addition, part of the cooling medium can cool the surrounding environment of the drill body 2, which can reduce the temperature of the surrounding environment of the drill body 2, thereby improving the thermal conductivity when the drill tip 1 dissipates heat outward.

[0097] Furthermore, by extending the supercooling channel 31 into the drill body 2, the cooling medium flowing along the supercooling channel 31 can cool the drill body 2, thereby preventing overheating. This arrangement also allows for a shorter distance between the second jet hole 22 and the drill tip 1 along the axial direction of the micro drill bit 100, enabling the cooling medium to cool the drill tip 1 more precisely, further improving the cooling effect of the micro drill bit 100. In addition, by separating the supercooling channel 31 from the chip removal groove 21, the influence of the supercooling channel 31 on the strength of the part of the drill body 2 with the chip removal groove 21 can be minimized, thereby preventing the drill body 2 from breaking during operation.

[0098] like Figure 11 , Figure 13 , Figure 14 As shown, in some embodiments of this application, the opening of the second jet hole 22 on the outer peripheral wall of the drill body 2 is located outside the chip removal groove 21. By setting the opening of the second jet hole 22 outside the chip removal groove 21, when the cooling medium is sprayed out from the second jet hole 22, the cooling medium can flow along the surface of the drill body 2 to the drill tip 1 to cool the drill tip 1. The cooling medium can also be sprayed onto the hole wall of the hole structure, and the cooling medium can simultaneously cool the hole wall to reduce the temperature of the hole wall and improve the machining quality of the hole structure.

[0099] Furthermore, Figure 11 In the two embodiments shown, the opening of the second jet hole 22 on the outer peripheral wall of the drill body 2 is spaced apart from the chip removal groove 21 along the axial direction of the drill body 2, so as to achieve the technical effect that the second jet hole 22 is located outside the chip removal groove 21. Figure 13In the embodiment shown, the opening of the second jet hole 22 on the outer peripheral wall of the drill body 2 is located on the side wall of the chip removal groove 21 (i.e., the back of the micro drill bit 100), so as to achieve the technical effect that the second jet hole 22 is located outside the chip removal groove 21.

[0100] like Figures 11-14 As shown, in some embodiments of this application, the supercooled channel 31 includes a plurality of supercooled sub-channels 311 connected in sequence. The radial dimension of any two adjacent supercooled sub-channels 311 gradually decreases in the direction from the drill shank 3 to the drill tip 1. By gradually reducing the radial dimension of the supercooled sub-channels 311, the amount of drill material removed from the supercooled sub-channels 311 during machining on the micro-drill bit 100 can be gradually reduced in the direction from the drill shank 3 to the drill tip 1. This ensures that the micro-drill bit 100 meets the rigidity design requirements, reduces runout during operation, and thus improves the machining accuracy of the micro-drill bit 100.

[0101] like Figures 11-14 As shown, in some embodiments of this application, in the direction from the end of the subcooling channel 31 away from the chip removal groove 21 to the end near the chip removal groove 21, the radial dimension of the nth subcooling subchannel 311 is drn, the diameter of the drill shank 3 is Ds, and the diameter of the drill body 2 is D. drn and Ds satisfy the following relationship: if n = 1, then 0.1Ds ≤ drn ≤ 0.2Ds; if n ≥ 2, then 0.1D ≤ drn ≤ 0.8D. The first subcooling subchannel 311 is located inside the drill shank 3, and the second to nth subcooling subchannels 311 are located inside the drill body 2. When the radial dimension dr1 of the first subcooling subchannel 311 is less than 0.1 times the diameter Ds of the drill shank 3, the flow capacity of the first subcooling subchannel 311 is poor, which in turn affects the flow rate of the cooling medium in the subsequent subcooling subchannels 311. When the radial dimension dr1 of the first subcooled subchannel 311 is greater than 0.2 times the diameter dimension Ds of the drill shank 3, the first subcooled subchannel 311 will affect the rigidity of the drill shank 1.

[0102] When the radial dimension drn of the second to nth supercooled sub-channels 311 is less than 0.1 times the diameter D of the drill body 2, the flow capacity of the second to nth supercooled sub-channels 311 is poor, which in turn affects the jet flow rate of the second jet hole 22. When the radial dimension drn of the second to nth supercooled sub-channels 311 is greater than 0.8 times the diameter D of the drill body 2, the second to nth supercooled sub-channels 311 will affect the rigidity of the drill body 2.

[0103] By ensuring that the radial dimension of the nth subcooled subchannel 311 satisfies the above relationship, the flow area of ​​each subcooled subchannel 311 can be increased as much as possible while ensuring that the micro drill bit 100 meets the rigidity design requirements.

[0104] Furthermore, the diameter of the second jet hole 22 is d1, and the angle between the second jet hole 22 and the central axis of the micro drill bit 100 is Ω. D and Ω satisfy the following relationships: 0.1D ≤ d1 ≤ 0.7D, 2° ≤ Ω < 90°. When the diameter of the second jet hole 22 is too small, the cooling medium flow rate at the open end of the second jet hole 22 is too low, resulting in low cooling efficiency of the micro drill bit 100, and the drill tip 1 is prone to overheating and accelerated wear. When the diameter of the second jet hole 22 is too large, excessive drill material needs to be removed during machining of the second jet hole 22 on the drill body 2, causing the micro drill bit 100 to fail to meet the rigidity design requirements. Therefore, by ensuring that the diameter of the second jet hole 22 satisfies the aforementioned relationships, the micro drill bit 100 can balance rigidity and cooling performance, thereby improving the product quality of the micro drill bit 100.

[0105] Furthermore, when the angle Ω between the second jet hole 22 and the central axis of the micro drill bit 100 is less than 2°, the jet direction of the second jet hole 22 cannot adequately cool the area around the drill body 2, and the second jet hole 22 is also difficult to machine into shape on the drill body 2. When the angle Ω between the second jet hole 22 and the central axis of the micro drill bit 100 is not less than 90°, the jet direction of the second jet hole 22 cannot cover the area of ​​the drill tip 1, resulting in insufficient cooling of the drill tip 1. By ensuring that the angle Ω between the second jet hole 22 and the central axis of the micro drill bit 100 satisfies the above relationship, it can be ensured that the second jet hole 22 can adequately cool the drill tip 1 of any type of micro drill bit 100.

[0106] like Figures 15-17 As shown, in some embodiments of this application, the main cutting edge 14 includes one or more sub-cutting edges. In a main cutting edge 14 with multiple sub-cutting edges, the multiple sub-cutting edges are connected in sequence, and there is an included angle between any two adjacent sub-cutting edges of each main cutting edge 14.

[0107] It should be understood that, since the main cutting edge 14 extends from the inside to the outside of the drill tip 1, during the drilling process of the micro drill 100, the distance between the main cutting edge 14 and the central axis of the micro drill 100 is different at different positions. That is, the main cutting edge 14 is subjected to different torque at different positions. Specifically, the torque on the main cutting edge 14 at the position close to the central axis of the micro drill 100 is greater than the torque on the position far away from the central axis of the micro drill 100.

[0108] By dividing the main cutting edge 14 into multiple sub-cutting edges, the workpiece material can be drilled in segments. The cutting edges of the multiple sub-cutting edges ensure that the torque on the main cutting edge 14 is uniform, thus allowing the main cutting edge 14 to wear evenly and thereby increasing the service life of the drill bit. Of course, in some embodiments, if the workpiece material drilled by the micro drill bit 100 has low hardness, by setting the main cutting edge 14 as a single sub-cutting edge, i.e., without segmenting the main cutting edge 14, the machining difficulty of the micro drill bit 100 can be reduced while still meeting the drilling requirements of the micro drill bit 100, thereby reducing the production cost of the micro drill bit 100.

[0109] In some embodiments of this application, the drill tip 1 has a plurality of main cutting edges 14, wherein the drill tip 1 is typically provided with two main cutting edges 14, but in some embodiments, for example Figure 22 As shown, the drill tip 1 can also be equipped with three or more main cutting edges 14 according to actual production needs. When the drill tip 1 has three main cutting edges 14, when drilling a workpiece using the micro drill 100, all three main cutting edges 14 simultaneously cut into the workpiece. Compared to a micro drill 100 with two main cutting edges 14, in a micro drill 100 with three main cutting edges 14, each main cutting edge 14 bears a smaller cutting load, thus making the drilling process of the micro drill 100 smoother. Furthermore, since the three main cutting edges 14 of the micro drill 100 participate in cutting simultaneously, the cutting force is more evenly distributed in three directions. This uniform force distribution helps reduce the working vibration and offset of the main cutting edges 14, thereby improving the machining stability of the micro drill 100.

[0110] Furthermore, the micro drill 100 with three main cutting edges 14 is also provided with three chip removal grooves 21. The three chip removal grooves 21 can work together to break the chips into smaller structures, and the chips can be effectively discharged out of the hole through the chip removal grooves 21. Therefore, the micro drill 100 with three main cutting edges 14 is suitable for deep hole machining, thereby effectively preventing chip blockage in the hole and reducing the temperature of the drill tip 1 of the micro drill 100.

[0111] Furthermore, in some embodiments, a mid-section is constructed with the central axis of the micro drill 100 and parallel to two adjacent main cutting edges 14, each main cutting edge 14 including a sub-cutting edge. In the same mid-section, the included angle between the projections of two adjacent main cutting edges 14 in the corresponding mid-section is the main vertex angle θ, which satisfies the relationship: 110°≤θ≤160°.

[0112] When the principal point angle θ is too small, the length of the cutting edge increases, and the contact area between the cutting edge and the workpiece increases. This reduces the axial cutting force of the micro drill 100 and makes it easier for cutting heat to be conducted and dissipated. However, it also leads to a decrease in the strength and wear resistance of the micro drill 100. Conversely, when the principal point angle θ is too large, the length of the cutting edge decreases, and the contact area between the cutting edge and the workpiece decreases. This increases the axial cutting force of the micro drill 100 and makes it difficult for cutting heat to be conducted and dissipated. However, it also increases the strength and wear resistance of the micro drill 100.

[0113] The principal apex angle θ of the micro drill 100 can be set according to the type of material to be processed. For example, when the micro drill 100 processes steel workpieces, the principal apex angle θ can be set to 118°, which can achieve a better balance between cutting force, drill strength and chip removal performance.

[0114] like Figure 15 As shown, in some other embodiments of this application, each main cutting edge 14 includes three sub-cutting edges connected sequentially from the drill tip 1 to the drill body 2. The three sub-cutting edges are a first sub-cutting edge 141, a second sub-cutting edge 142, and a third sub-cutting edge 143. The first sub-cutting edge 141 is connected to the chisel edge 13, the third sub-cutting edge 143 is connected to the chip groove 21, and the second sub-cutting edge 142 is connected between the first sub-cutting edge 141 and the third sub-cutting edge 143. That is, the first sub-cutting edge 141, the second sub-cutting edge 142, and the third sub-cutting edge 143 are connected sequentially to form the main cutting edge 14.

[0115] Furthermore, the included angle design between the first sub-cutting edge 141 and the second sub-cutting edge 142, and between the second sub-cutting edge 142 and the third sub-cutting edge 143, has two embodiments. The two embodiments are described in detail below.

[0116] In the first embodiment, the angle between the projections of any two adjacent first sub-cutting edges 141 in the mid-section is the first vertex angle θ1, the angle between the projections of any two adjacent second sub-cutting edges 142 in the mid-section is the second vertex angle θ2, and the angle between the projections of two adjacent third sub-cutting edges 143 in the corresponding mid-section is the third vertex angle θ3. The first proportionality coefficient is K1, and K1, θ1, θ2, and θ3 satisfy the following relationships: 110°≤θ1≤160°, θ2=-0.1θ1 2 +27θ1-1730,θ3=K1*(-0.05θ1 2 +13.5θ1-850), 0.4≤K1≤1, θ2>θ3.

[0117] The first vertex angle θ1, the second vertex angle θ2, and the third vertex angle θ3 change in a first gradual manner. Taking the first vertex angle θ1 as 130° and K1 = 1 as an example, substituting into the above relationship, we calculate that the second vertex angle θ2 is 90° and the third vertex angle θ3 is 60°. That is, the micro drill 100 can form a cutting force attenuation gradient of 130°-90°-60° in the axial direction. At this time, the first sub-cutting edge 141 can enhance the impact resistance of the drill tip 1, the second sub-cutting edge 142 can balance the cutting thickness and chip removal efficiency of the micro drill 100, and the third sub-cutting edge 143 can trim the hole wall. Furthermore, when θ1 is 110°, the micro drill 100 can form a cutting force attenuation gradient of 110°-30°-K1*30° in the axial direction. Since θ2 > θ3, K1 takes the value of 0.4 ≤ K1 < 1. The micro drill 100 can also form a cutting force attenuation gradient with gradually decreasing angle in the axial direction, which can achieve a uniform distribution of cutting force. When θ1 is 160°, the micro drill 100 can form a cutting force attenuation gradient of 160°-30°-K1*30° in the axial direction. Since θ2>θ3, K1 takes the value of 0.4≤K1<1. The micro drill 100 can also form a cutting force attenuation gradient with a gradually decreasing angle in the axial direction, which can achieve a uniform distribution of cutting force. Therefore, in the first gradient mode, when 110°≤θ1≤160°, a uniform distribution of cutting force can be achieved by dividing each main cutting edge 14 into three sub-cutting edges.

[0118] In the second embodiment, the angle between the projections of any two adjacent first sub-cutting edges 141 in the mid-section is the first vertex angle θ1, the angle between the projections of any two adjacent second sub-cutting edges 142 in the mid-section is the second vertex angle θ2, and the angle between the projections of any two adjacent third sub-cutting edges 143 in the mid-section is the third vertex angle θ3. The second proportionality coefficient is K2, and θ1, θ2, and θ3 satisfy the following relationships: 110°≤θ1≤160°, θ2=-0.144θ1 2 +38.88θ1-2504.4,θ3=K2*(-0.096θ1 2 +25.92θ1-1659.6), 1≤K2≤1.5, θ2<θ3.

[0119] The first vertex angle θ1, the second vertex angle θ2, and the third vertex angle θ3 change in a second gradual manner. Taking the first vertex angle θ1 as 130° and K2 = 1 as an example, substituting into the above relationship, we calculate that the second vertex angle θ2 is 88° and the third vertex angle θ3 is 116°. That is, the micro drill 100 can form a cutting force attenuation gradient of 130°-88°-116° in the axial direction. At this time, the first sub-cutting edge 141 can enhance the impact resistance of the drill tip 1, the second sub-cutting edge 142 can increase the cutting force of the micro drill 100, and the third sub-cutting edge 143 can increase the rigidity of the hole wall. Furthermore, when θ1 is 110°, the micro drill 100 can form a cutting force attenuation gradient of 110°-30°-K2*30° in the axial direction. Since θ2 < θ3, K2 takes the value of 1 < K2 ≤ 1.5. The micro drill 100 can also form a cutting force attenuation gradient in the axial direction with the angle first decreasing and then increasing, which can achieve a uniform distribution of cutting force. When θ1 is 160°, the micro drill 100 can form a cutting force attenuation gradient of 160°-30°-K2*30° in the axial direction. Since θ2 < θ3, K2 takes the value of 1 < K2 ≤ 1.5. The micro drill 100 can also form a cutting force attenuation gradient in the axial direction with the angle first decreasing and then increasing, which can achieve a uniform distribution of cutting force. Therefore, in the second gradient mode, when 110° ≤ θ1 ≤ 160°, a uniform distribution of cutting force can be achieved by dividing each main cutting edge 14 into three sub-cutting edges.

[0120] Therefore, by adopting different design ideas to design the included angle between the multiple sub-cutting edges of the main cutting edge 14, the micro drill bit can meet the requirements of different hole structures and material processing.

[0121] like Figure 15 As shown, in some embodiments of this application, the diameter of the drill body 2 is D, and the distance between the end of the first sub-cutting edge 141 away from the central axis of the micro drill bit 100 and the central axis of the micro drill bit 100 is R. 1a The distance between the end of the second sub-cutting edge 142 away from the central axis of the micro drill 100 and the central axis of the micro drill 100 is R. 2a The distance between the end of the third sub-cutting edge 143 furthest from the central axis of the micro drill 100 and the central axis of the micro drill 100 is R. 3a R 1a R 2a and R 3a Satisfies the relation: 0.2D≤R 1a ≤0.325D, 0.325D<R 2a ≤0.425D, 0.425D<R 3a<0.5D. In this way, by setting the connection between two adjacent sub-cutting edges at the preset diameter position of the drill tip 1, the transition position between the two adjacent sub-cutting edges can be made more suitable, and the main cutting edge 14 can drill the workpiece more smoothly, thereby reducing the wear rate at the connection between the two adjacent sub-cutting edges, and thus extending the service life of the micro drill bit 100.

[0122] In some embodiments provided in this application, those skilled in the art will readily conceive that the drill tip can be set to one, two, three or more drill tip apex angles based on the embodiments provided in this application.

[0123] Furthermore, such as Figure 16 As shown, the drill tip 1 is also provided with a main relief face 15, which is located behind the main cutting edge 14. The tangent of the main cutting edge 14 and the main relief face 15 form a relief angle φ. In the direction from the chisel edge 13 to the chip groove 21, the first sub-cutting edge 141 has two relief angles 17, and the second sub-cutting edge 142 and the third sub-cutting edge 143 each have one relief angle 17, where the relief angle 17 is denoted as φ. By increasing the number of relief angles 17 of the first sub-cutting edge 141, the clearance effect of the first sub-cutting edge 141 can be improved, the contact between the first sub-cutting edge 141 and the hole wall can be further reduced, thereby further reducing the torque on the first sub-cutting edge 141, further slowing down the wear rate of the first sub-cutting edge 141, and thus extending the service life of the micro drill bit 100. Furthermore, by giving the second sub-cutting edge 142 and the third sub-cutting edge 143 a back angle 17, the wear rate requirements of the second sub-cutting edge 142 and the third sub-cutting edge 143 can be met.

[0124] The drill tip 1 where the first sub-cutting edge 141 is located includes two relief angles φ1, and the relief angle φ1 near the relief face of the first sub-cutting edge 141 is... 11 The range is 1°-20°, preferably 5°-20°, and the clearance angle φ of the first sub-cutting edge 141 is far from the flank face of the first sub-cutting edge 141. 12 The range is 10°-50°, preferably 20°-40°, and φ 11 <φ 12 The back angle φ2 of the drill tip 1 where the second sub-cutting edge 142 is located ranges from 10° to 50°, preferably from 10° to 25°; the back angle φ3 of the drill tip 1 where the third sub-cutting edge 143 is located ranges from 10° to 50°, preferably from 10° to 25°.

[0125] The increased clearance angle of the drill tip enhances the clearance and cutting edge sharpness of the micro drill bit 100, allowing for better material cutting. The clearance angle is available in two types: a flat clearance angle and a rounded clearance angle. A flat clearance angle is generally used when machining easy-to-machine materials with low hardness, employing the G01 straight drill method. This provides a sharp cutting edge and better cutting force, suitable for high-speed machining. A rounded clearance angle is generally used when machining difficult-to-machine materials with high hardness, employing the G83 pecking drill method. This provides better cutting edge rigidity and wear resistance, suitable for high-intensity machining. When determining the clearance angle value, a larger clearance angle is used when machining easy-to-machine materials with low hardness, employing the G01 straight drill method. This provides a sharp cutting edge and better cutting force, suitable for high-speed machining. A smaller clearance angle is used when machining difficult-to-machine materials with high hardness, employing the G83 pecking drill method. This provides better cutting edge rigidity and wear resistance, suitable for high-intensity machining. The range of back angle values ​​depends on the material being machined. For example, when machining silicon carbide, which has a Vickers hardness of 2448.96 HV, it is a high-hardness and difficult-to-machine material. When machining it using G83, the range of back angle values ​​should be adjusted to reduce the first back angle of the drill tip by 8° to 12° and the second back angle of the drill tip by 25° to 35°. A suitable range of values ​​will result in a longer drill bit life and better wear resistance.

[0126] It should be noted that when the main cutting edge 14 includes a sub-cutting edge, the main cutting edge 14 has two clearance angles 17. Compared with setting one clearance angle 17, this setting can improve the clearance effect of the first sub-cutting edge 141, further reduce the contact between the first sub-cutting edge 141 and the hole wall, thereby further reducing the torque on the first sub-cutting edge 141 and further slowing down the wear rate of the first sub-cutting edge 141.

[0127] Furthermore, such as Figure 16 As shown, Figure 16 (1) When the main cutting edge 14 includes three sub-cutting edges, the back angle 17 of the main cutting edge 14 is shown in the figure. Figure 16 (2) In another embodiment of this application, the main cutting edge 14 includes two sub-cutting edges, and the back angle 17 of the main cutting edge 14 is shown in the schematic diagram.

[0128] Figure 16 (3) When the main cutting edge 14 includes a sub-cutting edge, the back angle 17 of the main cutting edge 14 is shown in the figure.

[0129] like Figure 17 As shown, in some embodiments of this application, the back face of the first sub-cutting edge 141 is provided with a second cutting edge 23. The second cutting edge 23 is adapted to abut against the hole wall of the hole structure to provide radial support for the drill body 2. The second cutting edge 23 can disperse the distribution of the drilling force of the micro drill bit 100 to avoid the drilling force of the micro drill bit 100 being too concentrated, which would cause the micro drill bit 100 to be easily damaged.

[0130] A chamfered surface 6 connects the first cutting edge 141 and the second cutting edge 23. The chamfered surface 6 alters the chip flow direction near the main cutting edge 14, thereby reducing friction and wear between the micro drill 100 and the workpiece, extending the drill's service life, and reducing cutting heat generation, thus strengthening the structural strength of the main cutting edge 14. An auxiliary plane is used, perpendicular to the central axis of the micro drill 100. The angle between the chamfered surface 6 and the auxiliary plane is the chamfer angle of the chamfered surface 6. The diameter of the drill body 2 is D, the width of the second cutting edge 23 is Dx, and the chamfer angle is γ. Dx and γ satisfy the following relationships: 0.07D ≤ Dx ≤ 0.13D, 2° ≤ γ ≤ 7°. By setting appropriate width and chamfer angle values ​​for the second cutting edge 23, chipping and other problems with the micro drill 100 can be minimized.

[0131] like Figure 18 As shown, in some embodiments of this application, the chip removal groove 21 includes an interconnected helical groove and a straight groove. The helical groove extends from the drill tip 1 along the axial direction of the drill body 2 in a direction away from the drill tip 1. The sidewall of the helical groove is provided with a secondary cutting edge, which is used for auxiliary drilling of the hole structure. The straight groove is located at the end of the helical groove away from the drill tip 1, and the straight groove extends along the axial direction of the drill body 2 in a direction away from the drill tip 1, that is, the extension direction of the straight groove is parallel to the central axis of the micro drill bit 100. The straight groove can increase the rigidity of the drill body 2 at the tail end of the chip removal groove 21, which can reduce the runout of the drill body 2 during operation, thereby improving the machining accuracy of the micro drill bit 100.

[0132] A first crushing structure 5 is provided inside the chip removal groove 21. The first crushing structure 5 extends from the end of the straight groove away from the drill tip 1 toward the drill tip 1. The first crushing structure 5 is formed by an array of multiple first crushing grooves 51. That is, the first crushing structure 5 can be composed of multiple first crushing grooves 51 in a single row and multiple columns, or multiple first crushing grooves 51 in multiple rows and multiple columns. Before the chips in the chip removal groove 21 are discharged from the chip removal groove 21, the first crushing structure 5 is used to crush the chips to reduce their size, thereby reducing the difficulty of discharging the chips from the chip removal groove 21.

[0133] like Figure 18 As shown, along the axial direction of the micro drill bit 100, the length of the chip removal groove 21 along the axial direction of the micro drill bit 100 is L, and the distance between the end of the first crushing structure 5 near the drill tip 1 and the drill tip 1 is L2. L and L2 satisfy the relationship: 0.6L≤L2≤0.7L. If the length of the first crushing structure 5 along the axial direction of the micro drill bit 100 is too small, the first crushing structure 5 will be unable to fully crush the chips, resulting in chips that are too large and difficult to be discharged from the chip removal groove 21.

[0134] If the length of the first crushing structure 5 along the axial direction of the micro drill bit 100 is too large, the size of the chips after being crushed by the first crushing structure 5 will be too small before the chips are discharged from the chip removal groove 21. The chips will easily accumulate in the hole structure, which will affect the machining quality of the hole structure and increase the heating rate of the micro drill bit 100. By setting the end of the first crushing structure 5 near the drill tip 1 (i.e., the starting end of the first crushing structure 5) at 0.6 to 0.7 times the length of the drill body 2, the size of the chips after being crushed by the first crushing structure 5 can be made more suitable, thereby facilitating the discharge of chips generated in the hole structure along the chip removal groove 21 to the outside of the hole structure.

[0135] Furthermore, such as Figure 18 As shown, the first fracturing structure 5 can be formed by combining multiple arrayed point-shaped first fracturing grooves 51 and multiple arrayed linear first fracturing grooves 51. The linear first fracturing grooves 51 are located on the side of the point-shaped first fracturing grooves 51 closer to the drill tip 1, and the distance between them is 0.03D to 0.04D, where D is the diameter of the drill body 2. Furthermore, as... Figure 19 As shown, the width t, depth h, and angle ω between the bottom and wall of the second crushing trough satisfy the following relationships: t=0.0053D+0.0147, h=0.014D-0.006, 0≤ω≤90°.

[0136] In some embodiments of this application, the chip removal groove 21 includes a plurality of sub-chip removal grooves 211 connected sequentially along the axial direction of the drill body 2. At least two sub-chip removal grooves 211 have different groove shapes, and the chip removal capacity (e.g., chip removal speed, guiding direction of metal chips) of the sub-chip removal grooves 211 with different groove shapes is different. By setting appropriate sub-chip removal grooves 211 in different areas of the drill body 2 and then connecting the plurality of sub-chip removal grooves 211 sequentially, when the chips are discharged sequentially along the plurality of sub-chip removal grooves 211 to the outside of the hole structure, the plurality of sub-chip removal grooves 211 cooperate to improve the chip removal smoothness of the chip removal groove 21, so that the chips can be discharged from the hole structure in time, thereby preventing the chips from accumulating in the hole structure.

[0137] Furthermore, the cross-sectional shape of the drill body 2 corresponding to different types of sub-chip removal grooves 211 is different. Taking the drill body 2 with two chip removal grooves 21 on its outer peripheral wall as an example, Figure 20 The diagram shows cross-sectional views of the drill body 2 of this application at the sub-chip removal grooves 211 of different groove types. The groove types of the multiple chip removal grooves 21 of the drill body 2 are all the same, and the drill body 2 can be constructed as an axisymmetric structure. It should be noted that the axis of symmetry of the drill body 2 is the central axis of the micro drill bit 100. Figure 20 (1) to (7) are cross-sectional views of the seven different types of sub-chip removal grooves 211 disclosed in this application. Specifically, each type of sub-chip removal groove 211 is constructed as a symmetrical structure, and the axis of symmetry of each sub-chip removal groove 211 passes through the central axis of the micro drill bit 100.

[0138] Figure 20 In (1), the wall of the chip removal groove 211 on one side is formed by three planes connected in sequence, and there is an included angle between any two adjacent planes. Figure 20 In (2), the wall of the chip removal groove 211 on one side is formed by two planes connected together, and there is an included angle between the two adjacent planes. Figure 20 In (3), the wall of one side of the sub-chip removal groove 211 is formed by a plane, and there is an included angle between the walls of the two sides of the sub-chip removal groove 211. Figure 20 (4) In this process, the wall of one side of the sub-chip removal groove 211 is formed by an arc surface, and the walls of the two sides of the sub-chip removal groove 211 are smoothly connected. Figure 20 In (5), the groove wall on one side of the sub-chip removal groove 211 is formed by connecting a plane and an arc surface. The arc surface is located on the side of the plane away from the axis of symmetry of the sub-chip removal groove 211, and there is a smooth transition between the plane and the arc surface. Figure 20 In (6), the groove wall on one side of the chip removal groove 211 is formed by connecting multiple arc surfaces in sequence, and the multiple arc surfaces are smoothly transitioned. Figure 20 In (7), the groove wall on one side of the chip removal groove 211 is formed by connecting multiple arc surfaces and multiple planes in a preset combination order.

[0139] It should be understood that the groove type of the sub-chip removal groove 211 in this application is not limited to the above seven types, and the groove type of the sub-chip removal groove 211 can be set according to the actual production situation.

[0140] By combining multiple sub-chip removal grooves 211, the rigidity of the drill body 2 can be improved, thereby reducing the runout of the drill body 2 when machining the workpiece, and thus improving the machining accuracy of the micro drill bit 100.

[0141] Furthermore, the length of the chip removal groove 21 along the axial direction of the micro drill bit 100 is L, the diameter of the drill body 2 is D, and the ratio of the length of the chip removal groove 21 to the diameter of the drill body 2 is A. The maximum number of sub-chip removal grooves 211 is positively correlated with the value of the above ratio, wherein A, L, and D satisfy the relationship: A = L / D. For example, in some embodiments, the maximum number of sub-chip removal grooves 211 is N, N = A / 5 + 2, where N is an integer and rounded up. For example, when A = 3, N = 3, or when A = 7, N = 4. By reasonably setting the maximum number of sub-chip removal grooves 211 according to the length and diameter of the chip removal groove 21, and selecting the groove type of the sub-chip removal grooves 211 based on the maximum number of sub-chip removal grooves 211, the chip removal capacity of the chip removal grooves 21 and the rigidity of the drill body 2 can be balanced.

[0142] As shown in the table below, the maximum number N of the chip removal grooves 211 is calculated for different values ​​of the length L of the chip removal grooves 21 along the axial direction of the micro drill bit 100, the diameter D of the drill body 2, and the ratio A of the length of the chip removal grooves 21 to the diameter of the drill body 2.

[0143] A L N 1 < A1 < 5 [D < L1 < 5D] 3 5 < A2 < 10 5D < L2≤ 10D 4 [10 < A3 < 15] <![CDATA[10D<L3≤15D]]> 5 <![CDATA[15<A4≦20]]> <![CDATA[15D<L4≤20D]]> 6 <![CDATA[A5≧20]]> <![CDATA[L5>20D]]> A / 5+2(rounded up)

[0144] Furthermore, such as Figure 21 As shown, there is one sub-chip removal groove 211 located at the drill tip 1, and the length dimension of the sub-chip removal groove 211 located at the drill tip 1 along the axial direction of the micro drill bit 100 is P1. The length dimension of each sub-chip removal groove 211 located in the drill body 2 along the axial direction of the micro drill bit 100 is the same. And let the length dimension of each sub-chip removal groove 211 located in the drill body 2 along the axial direction of the micro drill bit 100 be P2. P1, P2, L and N satisfy the relationship: P2=(L-P1) / (N-1).

[0145] The table below shows the length P of each sub-chip removal groove 211 along the axial direction of the micro drill bit 100 under different values ​​of the maximum number N of sub-chip removal grooves 211. n .

[0146]

[0147]

[0148] Furthermore, based on Figure 20 The table shows various slot types of the sub-chip removal groove 211. The following table shows different combinations of slot types of the sub-chip removal groove 211 when the chip removal groove 21 includes multiple sub-chip removal grooves 211 and at least two sub-chip removal grooves 211 have different slot types. It should be noted that types (1), (2), ... (n) in the table correspond to... Figure 20 Type (1), Type (2) ... Type (n).

[0149]

[0150] In some embodiments of this application, the main flank face 15 may be provided with a second crushing structure, which includes a plurality of second crushing grooves arranged in sequence. The second crushing grooves are used to crush the chips flowing through the main flank face 15, thereby reducing the size of the chips and further facilitating the discharge of chips from the hole structure, and further reducing the working temperature of the drill tip 1.

[0151] like Figure 2 and Figure 20As shown, in some embodiments of this application, the main flank face 15 is provided with a toothed cleavage 151 recessed into the drill shank 3. The toothed cleavage 151 communicates with the chip removal groove 21 and extends from the chisel edge 13 to the outer circle of the drill tip 1. A chamfered surface with a smooth transition is provided between the toothed cleavage 151 and the flank face of the sub-cutting edge farthest from the drill tip. When the toothed cleavage 151 is formed on the main flank face 15, a portion of the chisel edge 13 will be removed. Figure 20 (The chisel edge is not shown). At the same time, a sub-cutting edge is added to the main cutting edge 14 adjacent to the main flank face 15. This sub-cutting edge is the fourth sub-cutting edge 144, so that the first sub-cutting edge 141 is connected to the chisel edge 13 through the fourth sub-cutting edge 144. The fourth sub-cutting edge 144 is mainly used to cut off the chips, so that the chips can be smoothly discharged into the chip removal groove 21 of the drill body 2 through the tooth gap 151, and will not get stuck at the drill tip 1. At the same time, the chisel edge 13 is shortened, the axial resistance of drilling is reduced, the centering accuracy of the micro drill bit 100 is improved, and the chip removal capability of the flank face is improved. In this design, the last sub-cutting edge of the main relief face 15 forms a chamfered surface 16 at the connection between its relief face and the tooth clearance. The chamfered surface 16 can be formed by removing a portion of the main relief face 15. The chamfered surface 16 and the tooth clearance 151 can be transitioned using an arc. The chamfered surface 16 creates a clearance area between the tooth clearance 151 and the main relief face 15, improving chip flow and reducing chip accumulation within the hole structure. To further enhance chip removal capability, a second jet hole 22 can also be located within the tooth clearance to further improve the cooling, lubrication, and chip removal capabilities of the drill tip.

[0152] In some embodiments of this application, such as Figure 23 and 24 As shown, to improve the chip-receiving and chip-removing function of the micro drill 100 during machining, a backlash 151 is provided on the flank face of the drill tip 1. The backlash 151 includes: a backlash chip-receiving groove angle η1, ranging from 25° to 70°; a backlash yaw angle η2, ranging from 20° to 50°; and a backlash development angle η3, ranging from 50° to 90°. A larger backlash chip-receiving groove angle η1 results in a larger chip removal space, suitable for easily machinable materials; a smaller backlash chip-receiving groove angle η1 results in better rigidity of the drill tip 1, suitable for difficult-to-machinable materials. A larger backlash yaw angle η2 results in a shorter cutting edge, a smaller chip removal space, and better rigidity of the drill tip 1, suitable for difficult-to-machinable materials; a smaller backlash yaw angle η2 results in a longer cutting edge, a larger chip removal space, and faster machining efficiency, suitable for easily machinable materials. A larger backlash development angle η3...

[0153] A larger chip removal space is suitable for easily machinable materials, while a smaller backlash angle η3 results in better rigidity of the drill tip 1, making it suitable for difficult-to-machinable materials. Furthermore, the backlash 151 of the drill tip 1 is designed with optimized stress distribution to prevent stress concentration, thereby enhancing the durability of the micro-drill 100.

[0154] It should be noted that in some embodiments of this application, the relevant structural dimensions and angle values ​​may have certain errors during the processing, but this will not affect the effect of the embodiments provided by this application, and these values ​​can be easily obtained by those skilled in the art in conjunction with the embodiments of this application.

[0155] This application also provides a processing device, including a driving device, a clamping device, and a micro drill bit 100 as described in the previous embodiment. The clamping device clamps the micro drill bit 100, and the driving device drives the micro drill bit to rotate through the clamping device to process the workpiece.

[0156] According to the processing equipment of this application, the processing equipment has a micro drill bit 100. When the processing equipment uses the micro drill bit 100 to process a workpiece, a first jet hole 41 is provided on the transition part 4 of the micro drill bit 100. The first jet hole 41 can obtain a cooling medium from an external cold source and spray the cooling medium onto the drill tip 1. The cooling medium can cool the drill tip 1 to reduce the temperature of the drill tip 1. Compared with the prior art, the heating rate of the drill bit 1 can be slowed down, thereby reducing the wear rate of the micro drill bit 100, thereby improving the processing quality of the hole structure and extending the service life of the micro drill bit 100.

[0157] The above description is only a preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of this application, and these improvements and substitutions should also be considered within the scope of protection of this application.

Claims

1. A miniature drill bit, characterized in that, include: The drill tip, drill body, and drill shank are connected sequentially from front to back along the axial direction of the micro drill bit; The outer peripheral wall of the drill body is provided with a chip removal groove, which extends from the drill tip to the drill shank; A transition section is provided between the drill shank and the drill body, and the outline of the outer peripheral wall of the transition section smoothly transitions from the drill shank to the drill body. The drill shank is provided with a supercooling channel, one end of which extends to the transition section. The outer peripheral wall of the transition section is provided with a first jet hole, which communicates with the supercooling channel and is open towards the drill tip. The angle between the first jet orifice and the central axis of the micro drill bit is α. In the cross-section of the drill shank, an auxiliary circle is constructed with the axis of the drill shank as the center and the distance from the axis of the inlet end of the first jet orifice to the axis of the drill shank as the radius. The diameter of the auxiliary circle is Tk. The total length of the drill body and the drill tip is L1. The diameter of the drill body is D. The diameter of the drill shank is Ds. A conical surface is constructed with the straight line connecting the outer peripheral wall of the front end of the drill shank to the outer peripheral wall of the rear end of the drill body as the contour line. The cone angle of the conical surface is β, and the angle coefficient is δ. δ, α, Tk, L1, D, Ds, and β satisfy the following relationship: 0.75≤δ≤0.

95.

2. The miniature drill bit according to claim 1, characterized in that, The outer peripheral wall of the transition section is provided with a plurality of first jet holes, which are arranged sequentially along the circumference of the transition section.

3. The miniature drill bit according to claim 1, characterized in that, The drill shank is provided with a plurality of supercooling channels, which are arranged sequentially at intervals along the circumference of the drill shank, and each supercooling channel is connected to at least one of the first jet holes.

4. The miniature drill bit according to claim 3, characterized in that, The radial dimension of the subcooling channel is d, and Tk, d and Ds satisfy the following relationship: Tk = 0.68Ds - 0.554, 0.08Ds ≤ d ≤ 0.7Ds.

5. The miniature drill bit according to claim 1, characterized in that, The drill tip is provided with a transverse cutting edge and a main cutting edge at the end away from the drill body. The main cutting edge is connected between the transverse cutting edge and the chip removal groove. The main cutting edge includes one or more sub-cutting edges. In the main cutting edge having multiple sub-cutting edges, the multiple sub-cutting edges are connected in sequence. There is an included angle between any two adjacent sub-cutting edges of each main cutting edge.

6. The miniature drill bit according to claim 5, characterized in that, The drill tip has multiple main cutting edges that pass through the central axis of the micro drill bit and form a mid-section parallel to two adjacent main cutting edges. Each main cutting edge includes a sub-cutting edge. In the same mid-section, the angle between the projections of two adjacent main cutting edges in the corresponding mid-section is θ, where θ satisfies the relationship: 110°≤θ≤160°.

7. The miniature drill bit according to claim 5, characterized in that, The drill tip has a plurality of main cutting edges that pass through the central axis of the micro drill bit and are parallel to the cross section formed by two adjacent main cutting edges. Each main cutting edge includes a first sub-cutting edge, a second sub-cutting edge, and a third sub-cutting edge connected sequentially from the drill tip to the drill body. The first sub-cutting edge is connected to the chisel edge. Within the same mid-section, the angle between the projections of two adjacent first sub-cutting edges onto the corresponding mid-section is θ1, the angle between the projections of two adjacent second sub-cutting edges onto the corresponding mid-section is θ2, and the angle between the projections of two adjacent third sub-cutting edges onto the corresponding mid-section is θ3. The first proportionality coefficient is K1, and θ1, θ2, θ3, and K1 satisfy the following relationships: 110°≤θ1≤160°, θ2=-0.1θ1 2 +27θ1-1730,θ3=K1*(-0.05θ1 2 +13.5θ1-850), 0.4≤K1≤1, θ2>θ3.

8. The miniature drill bit according to claim 5, characterized in that, The drill tip has a plurality of main cutting edges that pass through the central axis of the micro drill bit and are parallel to the cross section formed by two adjacent main cutting edges. Each main cutting edge includes a first sub-cutting edge, a second sub-cutting edge, and a third sub-cutting edge connected sequentially from the drill tip to the drill body. The first sub-cutting edge is connected to the chisel edge. Within the same mid-section, the angle between the projections of two adjacent first sub-cutting edges onto the corresponding mid-section is θ1, the angle between the projections of two adjacent second sub-cutting edges onto the corresponding mid-section is θ2, and the angle between the projections of two adjacent third sub-cutting edges onto the corresponding mid-section is θ3. The second proportionality coefficient is K2, and θ1, θ2, θ3, and K2 satisfy the following relationships: 110° ≤ θ1 ≤ 160°, θ2 = -0.144θ1 2 +38.88θ1-2504.4,θ3=K2*(-0.096θ1 2 +25.92θ1-1659.6), 1≤K2≤1.5, θ2<θ3.

9. The micro drill bit according to claim 7 or 8, characterized in that, The diameter of the drill body is D, and the distance between the end of the first sub-cutting edge away from the central axis of the micro drill bit and the central axis of the micro drill bit is R. 1a The distance R between the end of the second sub-cutting edge furthest from the central axis of the micro drill bit and the central axis of the micro drill bit. 2a The distance between the end of the third sub-cutting edge furthest from the central axis of the micro drill bit and the central axis of the micro drill bit is R. 3a R 1a R 2a and R 3a Satisfies the relation: 0.2D≤R 1a ≤0.325D, 0.325D<R 2a ≤0.425D, R 3a =0.5D.

10. The micro drill bit according to claim 7 or 8, characterized in that, The drill tip is also provided with a main relief face, which is located behind the main cutting edge, and the tangent of the main cutting edge and the main relief face form a relief angle φ. In the direction from the transverse cutting edge to the chip groove, the first sub-cutting edge has two relief angles, and the second sub-cutting edge and the third sub-cutting edge each have one relief angle. The clearance angle φ of the first sub-cutting edge near the flank face of the first sub-cutting edge 11 The range is 1°-20°, and the clearance angle φ of the first sub-cutting edge away from the flank face of the first sub-cutting edge is... 12 The range is 10°-50°, and φ 11 <φ 12 ; The clearance angle φ2 of the second sub-cutting edge ranges from 10° to 50°; The back angle φ3 of the third sub-cutting edge ranges from 10° to 50°.

11. The miniature drill bit according to claim 10, characterized in that, The first sub-cutting edge has a second cutting edge on its back face. The second cutting edge of the first sub-cutting edge has a chamfered surface connected to the cutting edge. An auxiliary plane is used with a plane perpendicular to the central axis of the micro drill bit. The angle between the chamfered surface and the auxiliary plane is the chamfer angle of the chamfered surface. The diameter of the drill body is D, the width of the second cutting edge is Dx, and the size of the chamfer angle is γ. Dx and γ satisfy the following relationship: 0.07D≤Dx≤0.13D, 2°≤γ≤7°.

12. The miniature drill bit according to claim 5, characterized in that, The main cutting edge includes multiple sub-cutting edges connected in sequence. At least two adjacent sub-cutting edges are connected at the flank face, and / or the drill tip is connected to the outer periphery of the drill body. The transition surface is provided with microtexture, and a cutting edge band is provided between the microtexture and the cutting edge of each sub-cutting edge. The microtexture is formed by an array of multiple microgrooves.

13. The miniature drill bit according to claim 12, characterized in that, The drill body includes a first cutting edge, and the transition surface at the connection between the drill tip and the drill body is provided on the first cutting edge. The transition surface is constructed as a circular arc transition surface, a transition plane, or an obtuse angle transition surface; the micro-groove is pore-shaped or groove-shaped arranged longitudinally.

14. The miniature drill bit according to claim 1, characterized in that, The chip removal groove includes a spiral groove and a straight groove connected to each other. The spiral groove extends from the drill tip along the axial direction of the drill body in a direction away from the drill tip. The sidewall of the spiral groove is provided with a secondary cutting edge. The straight groove is located at the end of the spiral groove away from the drill tip and extends along the axial direction of the drill body in a direction away from the drill tip. The chip removal groove is provided with a first crushing structure, which extends from the end of the straight groove away from the drill tip toward the drill tip. The first crushing structure is formed by an array of multiple first crushing grooves. In the axial direction of the micro drill bit, the length of the chip removal groove is L, and the distance between the end of the first crushing structure near the drill tip and the drill tip is L2. L and L2 satisfy the relationship: 0.6L≤L2≤0.7L.

15. The miniature drill bit according to claim 1, characterized in that, The chip removal groove includes a plurality of sub-chip removal grooves connected sequentially along the axial direction of the drill body, and at least two of the sub-chip removal grooves have different groove shapes; The length of the chip removal groove along the axial direction of the micro drill bit is L, the diameter of the drill body is D, the ratio of the length of the chip removal groove to the diameter of the drill body is A, the maximum number of sub-chip removal grooves is positively correlated with the value of the ratio, the maximum number of sub-chip removal grooves is N, and N and A satisfy the relationship: N = A / 5 + 2, where N is an integer and rounded up.

16. The miniature drill bit according to claim 1, characterized in that, The drill tip is also provided with a main back face, and the main back face is provided with a second crushing structure, the second crushing structure including a plurality of second crushing grooves arranged in sequence.

17. The miniature drill bit according to claim 5, characterized in that, The drill tip is also provided with a main flank face and a chisel edge. The main flank face is provided with a toothed groove that is recessed into the drill shank. The toothed groove is connected to the chip removal groove and extends from the chisel edge to the outer circle of the drill tip. A chamfered surface with a smooth transition is provided between the toothed groove and the flank face of the sub-cutting edge that is farthest from the drill tip.

18. A processing device, characterized in that, The device includes a drive unit, a clamping device, and a micro drill bit as described in any one of claims 1-17, wherein the clamping device clamps the micro drill bit, and the drive unit drives the micro drill bit to rotate through the clamping device.

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