Micro drill bit and machining equipment

Abstract

The invention relates to the technical field of drilling machining, and discloses a microbit and machining equipment. The microbit comprises a drill tip, a drill body and a drill handle which are sequentially connected from front to back in the axial direction of the microbit. 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, a first jet hole communicated with the supercooling channel is formed in the peripheral wall of the transition part and is open towards the drill tip, the supercooling channel is suitable for being communicated with an external cold source, and the first jet hole is open towards the drill tip. Therefore, the first jet flow hole is formed in the transition part, the first jet flow hole can obtain the cooling medium from an external cold source and spray the cooling medium to the drill tip, the cooling medium can cool the drill tip to reduce the temperature of the drill tip, and compared with the prior art, the temperature rise speed of the drill bit can be reduced, so that the abrasion speed of the micro drill bit can be reduced, and the service life of the drill bit is prolonged. Therefore, the processing quality of the hole structure can be improved, and the service life of the microbit is prolonged.

Description

Technical Field

[0001] The present application relates to the technical field of drilling processing, and in particular to a micro drill bit and a processing device having the micro drill bit. Background Art

[0002] In related technologies, drill bits cut material on the surface of a workpiece to form a pore structure on the workpiece surface. Micro drill bits can be used to process pore structures with very small pore sizes (for example, pore structures with pore sizes of 0.1mm to 1.0mm), and therefore micro drill bits are widely used in the semiconductor industry. Semiconductors have high requirements for the processing quality of pore structures, and the processing materials are powder die-cast materials such as single-crystal silicon or polycrystalline silicon. When drilling the surface of semiconductor products at high speed, the heat generated by the micro drill bit is difficult to dissipate out of the hole in time due to the small size of the hole formed by the micro drill bit. This causes the drill tip to overheat, resulting in rapid wear of the micro drill bit, which in turn leads to deformation and hole collapse of the processed pore structure, and also shortens the service life of the micro drill bit. Summary of the Invention

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

[0004] In order to achieve the above objectives, the present application provides a micro drill.

[0005] The present application further provides a processing device.

[0006] The micro drill bit according to the present application comprises: a drill tip, a drill body and a drill shank connected in sequence 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, and the chip removal groove extends from the drill tip to the drill shank; a transition portion is connected between the drill shank and the drill body, and the contour line of the outer peripheral wall of the transition portion smoothly transitions from the drill shank to the drill body; an overcooling channel is provided in the drill shank, one end of the overcooling channel extends to the transition portion, and the outer peripheral wall of the transition portion is provided with a first jet hole, the first jet hole is communicated with the overcooling channel, and the first jet hole is open toward the drill tip; the first jet hole is connected to the The 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 relationship: 0.75≤δ≤0.95.

[0007] According to the micro drill bit of the present application, a first jet hole is provided on the transition portion, and the first jet hole can obtain a cooling medium from an external cold source and spray the cooling medium toward the drill tip. The cooling medium can cool the drill tip to reduce the temperature of the drill tip. 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, thereby improving the processing quality of the hole structure and extending the service life of the micro drill bit.

[0008] In some examples of the present application, a plurality of the first jet holes are provided on the outer peripheral wall of the transition portion, and the plurality of the first jet holes are arranged in sequence along the circumference of the transition portion.

[0009] In some examples of the present application, a plurality of the supercooling channels are provided in the drill shank, and the plurality of the supercooling channels are sequentially spaced apart along the circumference of the drill shank, and each of the supercooling channels is connected to at least one of the first jet holes.

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

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

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

[0013] In some examples of the present application, the drill tip has a plurality of main cutting edges to construct a mid-section passing through the central axis of the micro drill bit and parallel to two adjacent main cutting edges, each of the main cutting edges includes a first sub-cutting edge, a second sub-cutting edge, and a third sub-cutting edge connected in sequence from the drill tip to the drill body, and the first sub-cutting edge is connected to the chisel edge; in 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 first proportional coefficient is K1, and θ1, θ2, θ3 and K1 satisfy the relationship: 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 the present application, the drill tip has a plurality of main cutting edges to construct a mid-section passing through the central axis of the micro drill bit and parallel to two adjacent main cutting edges, each of the main cutting edges includes a first sub-cutting edge, a second sub-cutting edge, and a third sub-cutting edge connected in sequence from the drill tip to the drill body, and the first sub-cutting edge is connected to the chisel edge; in 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 proportional coefficient is K2, θ1, θ2, θ3 and K2 satisfy the relationship: 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 the present 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 between the end of the second sub-cutting edge away from the central axis of the micro drill and the central axis of the micro drill is R 2a The distance between the end of the third sub-cutting edge away from the central axis of the micro drill and the central axis of the micro drill is R 3a , R 1a 、R 2a , and R 3a Satisfy the relationship: 0.2D≤R 1a ≤0.325D, 0.325D<R 2a ≤0.425D, R 3a =0.5D.

[0016] In some examples of the present application, the drill tip is further provided with a main flank face, the main flank face is located on the rear side of the main cutting edge, and a flank angle φ is formed between the tangent surface of the main cutting edge and the main flank face. In the direction from the chisel edge to the chip groove, the first sub-cutting edge has two flank angles, and the second sub-cutting edge and the third sub-cutting edge each have one flank angle; the flank angle φ of the flank face of the first sub-cutting edge close to the first sub-cutting edge is 11 The range is 1°-20°, and the clearance angle φ of the first sub-cutting edge away from the flank surface of the first sub-cutting edge is 12 The range is 10°-50°, and φ 11 <φ 12 ; The back 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°.

[0017] In some examples of the present application, the back cutting surface of the first sub-cutting edge is provided with a second edge band, a chamfered surface is connected between the first sub-cutting edge and the second edge band, a plane perpendicular to the central axis of the micro drill bit is used as an auxiliary plane, the angle between the chamfered surface and the auxiliary plane is the chamfer angle of the chamfered surface, the diameter dimension of the drill body is D, the width dimension of the second edge band is Dx, the size of the chamfered angle is γ, and Dx and γ satisfy the relationship: 0.07D≤Dx≤0.13D, 2°≤γ≤7°.

[0018] In some examples of the present application, the main cutting edge includes a plurality of sub-cutting edges connected in sequence, and the connection between the back surfaces of at least two adjacent sub-cutting edges, and / or the connection between the drill tip and the outer periphery of the drill body is provided with a transition surface, the transition surface is provided with a micro-texture, and a cutting edge is provided between the micro-texture and the cutting edge of each sub-cutting edge, and the micro-texture is formed by an array of multiple micro-grooves.

[0019] In some examples of the present 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 micro-groove body is hole-shaped or groove-shaped arranged longitudinally.

[0020] In some examples of the present application, the chip 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 toward the direction away from the drill tip, the side wall of the spiral groove is provided with a secondary cutting edge, the straight groove is provided at one end of the spiral groove away from the drill tip, and the straight groove extends along the axial direction of the drill body toward the direction away from the drill tip; a first crushing structure is provided in the chip groove, the first crushing structure extends from the end of the straight groove away from the drill tip toward the drill tip, and 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 dimension of the chip groove is L, and the spacing distance between the end of the first crushing structure close to the drill tip and the drill tip is L2, and L and L2 satisfy the relationship: 0.6L≤L2≤0.7L.

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

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

[0023] In some examples of the present application, the drill tip is further provided with a main flank surface and a transverse edge, the main flank surface is provided with a tooth gap recessed toward the drill shank, the tooth gap is connected to the chip groove, and the tooth gap extends from the transverse edge to the outer circle of the drill tip, and a chamfered surface with a smooth transition is provided between the tooth gap and the flank surface of the sub-cutting edge farthest from the drill tip.

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

[0025] According to the processing equipment of the present 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 set 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 to the drill tip. The cooling medium can cool the drill tip to reduce the drill tip temperature. Compared with the existing technology, the drill bit heating rate can be slowed down, thereby reducing the wear rate of the micro drill bit, and then the processing quality of the hole structure can be improved, and the service life of the micro drill bit can be extended. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a front view of a micro drill bit according to an embodiment of the present application;

[0027] Figure 2 is a side view of a micro drill bit according to an embodiment of the present application having two main cutting edges;

[0028] Figure 3 Schematic diagrams of three implementations of the transition surface of the embodiment of the present application;

[0029] Figure 4 This is a schematic diagram of the micro-grooves of the embodiment of the present application when the micro-grooves are arranged as dot-shaped micro-grooves on the transition surface;

[0030] Figure 5 This is a schematic diagram of the embodiment of the present application in which the micro-grooves are arranged on the transition surface as linear micro-grooves;

[0031] Figure 6 This is a schematic diagram of the micro-grooves of the embodiment of the present application after being arranged on the transition surface when the micro-grooves are structured as planar micro-grooves;

[0032] Figure 7 1 is a front view of nine implementation modes of the transition portion of the embodiment of the present application;

[0033] Figure 8 is a front view of a micro drill bit according to an embodiment of the present application having multiple supercooling channels and multiple first jet holes;

[0034] Figure 9 yes Figure 8 A partial enlarged view of

[0035] Figure 10 is a front view of a micro drill bit according to an embodiment of the present application having a supercooling channel and a plurality of first jet holes;

[0036] Figure 111 is a front view of two embodiments of a micro drill bit according to an embodiment of the present application having a supercooling channel and a plurality of second jet holes, and the second jet holes are located outside the chip discharge groove;

[0037] Figure 12 It is a front view of another embodiment of the micro drill bit of the present application embodiment having a supercooling channel and a plurality of second jet holes, and the second jet holes are located outside the chip discharge groove;

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

[0039] Figure 14 yes Figure 13 A partial enlarged view of

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

[0041] Figure 16 Schematic diagram of the back angle of the main cutting edge of an embodiment of the present application;

[0042] Figure 17 Schematic diagram of the chamfered surface of an embodiment of the present application;

[0043] Figure 18 is a schematic diagram of a first crushing structure according to an embodiment of the present application;

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

[0045] Figure 20 1 is a cross-sectional view of seven different embodiments of the sub-chip flutes of the present application;

[0046] Figure 21 is a front view of a plurality of sub-chip flutes connected in sequence to form a chip flute according to an embodiment of the present application;

[0047] Figure 22 is a side view of a micro drill bit according to an embodiment of the present application having three main cutting edges;

[0048] Figure 23 2 is a schematic structural diagram of a micro drill bit according to an embodiment of the present application, showing the angle of the tooth gap chip groove on the drill tip;

[0049] Figure 24 This is a structural schematic diagram of the micro drill bit of an embodiment of the present application showing the tooth gap deflection angle and tooth gap expansion angle on the drill tip.

[0050] In the figure, 100, micro drill bit;

[0051] 1. Drill tip; 11. Transition surface; 12. Microtexture; 121. Microgrooves; 122. First edge band; 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 surface; 151. Tooth clearance; 16. Chamfered surface; 17. Back angle;

[0052] 2. drill body; 21. chip flute; 211. sub-chip flute; 22. second jet hole; 23. second margin;

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

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

[0055] 5. First crushing structure; 51. First crushing groove; 6. Chamfered surface. DETAILED DESCRIPTION

[0056] The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0057] like Figure 1-Figure 24 As shown, an embodiment of the present application discloses a micro drill 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 100, and the driving device drives the clamping device to drive the micro drill 100 to rotate around the central axis of the micro drill 100. The micro drill 100 can process and form a hole structure on the surface of the workpiece. Specifically, the micro drill 100 is used to process a hole structure with a diameter less than 3.175 mm. For example, the micro drill 100 can process and form a hole structure of 0.1 mm to 1.0 mm.

[0058] like Figure 1-Figure 24 As shown, a micro drill bit 100 according to an embodiment of the present application includes: a drill tip 1, a drill body 2, and a drill shank 3, which are connected in sequence from front to back along the axial direction of the micro 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. The clamping device, driven by a driving device, can drive the drill shank 3 to rotate the drill tip 1 and drill body 2. The outer peripheral wall of the drill body 2 is provided with a spiral chip groove 21, which extends from the drill tip 1 to the drill shank 3. After the drill tip 1 peels material from the workpiece surface, the material chips are discharged outside the hole along the chip groove 21, thereby reducing the accumulation of material chips in the hole.

[0059] like Figure 7As shown, a transition portion 4 is connected between the drill shank 3 and the drill body 2. The contour of the outer peripheral wall of the transition portion 4 smoothly transitions from the drill shank 3 to the drill body 2. Thus, the transition portion 4 can provide a smooth transition between the drill shank 3 and the drill body 2. Specifically, the transition portion 4 can be configured as a body of revolution with the central axis of the micro drill bit 100 as the rotation axis. Moreover, along the axial direction of the micro drill bit 100, the contour of the transition portion 4 can be a combination of a straight line and a curve. Figure 7 (1)- Figure 7 (9) shows the specific structure of the transition portion 4 of the micro drill 100 of the present application in different embodiments.

[0060] Furthermore, if Figures 8-13 As shown, a subcooling channel 31 may be provided within the drill shank 3. One end of the subcooling channel 31 extends to the transition portion 4. The outer peripheral wall of the transition portion 4 may be provided with a first jet hole 41. The first jet hole 41 is connected to the subcooling channel 31 and is open toward the drill tip 1. The subcooling channel 31 is suitable for communicating with an external cooling source. The external cooling source can provide a cooling medium to the subcooling channel 31. The cooling medium can then flow into the first jet hole 41 and be ejected through the outlet of the first jet hole 41 to the drill tip 1, thereby cooling and lubricating the drill tip 1, preventing the drill tip 1 from overheating and causing excessive wear of the micro drill bit 100. This can improve the processing 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 a gas or a liquid. When the cooling medium is a gas, the cooling medium can specifically be air or nitrogen, etc. When the cooling medium is a liquid, the cooling medium can be water or a coolant, etc. The specific type of cooling medium can be set according to the workpiece to be processed by the micro drill 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 relationship: 0.75≤δ≤0.95.

[0063] The distance Tk between the axis of the inlet end of the first jet hole 41 and the axis of the drill shank 3 affects the uniformity of the coolant distribution. An appropriate spacing Tk ensures uniform distribution of the coolant within the drill shank 3. The combined length L1 of the drill body 2 and drill tip 1 affects the coolant spray distance. If L1 is too long, the coolant cannot flow to the drill tip 1; if L1 is too short, the coolant cannot fully cool the drill tip 1. The diameter D of the drill body 2 limits the supercooling area of the supercooling channel 31, thereby affecting the coolant flow rate. The taper angle β affects the shape of the opening of the first jet hole 41, thereby affecting the spray direction of the first jet hole 41. The angle coefficient δ can be determined through multiple experiments. In this application, the angle coefficient δ ranges from 0.75 to 0.95. The angle coefficient δ is used to reduce the directional deviation of the first jet hole 41 during actual use, allowing the first jet hole 41 to more accurately spray the coolant toward the drill tip 1.

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

[0065] Furthermore, the outer wall of the drill shank 3 is provided with an inlet connected to the supercooling channel 31, and the inlet is connected to an external cold source, and the external cold source can provide cooling medium to the supercooling channel 31 through the inlet. In some specific embodiments, such as Figure 8 、 Figure 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 is arranged to extend 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 the present application, the outer peripheral wall of the transition portion 4 may be provided with a plurality of first jet holes 41, and the plurality of first jet holes 41 are sequentially arranged along the circumference of the transition portion 4. The plurality of first jet holes 41 are all connected to the supercooling channel 31, and the cooling medium in the supercooling channel 31 can be diverted to the plurality of first jet holes 41, so that the plurality of first jet holes 41 can jointly provide cooling medium to the drill tip 1.

[0067] Preferably, multiple first jet holes 41 can be evenly spaced and arranged on the outer peripheral wall of the transition portion 4. By utilizing multiple first jet holes 41 to simultaneously provide cooling medium to the drill tip 1, the drill tip 1 can be cooled from multiple directions, ensuring a uniform temperature around the drill tip 1. This can prevent the drill tip 1 from breaking due to excessive local temperature differences. It should be noted that the first jet holes 41 can be shaped like a circle, a strip, or a square.

[0068] like Figure 8 、 Figure 9 As shown, in some other embodiments of the present application, a plurality of supercooling channels 31 may be provided in the drill shank 3, and the plurality of supercooling channels 31 are sequentially spaced along the circumference of the drill shank 3, and each supercooling channel 31 is connected to at least one first jet hole 41. Figure 8 In the illustrated embodiment, a plurality of supercooling channels 31 are provided in a one-to-one correspondence with a plurality of first jet holes 41 , that is, each supercooling channel 31 is connected to a first jet hole 41 , respectively. By controlling the flow rate of the cooling medium in the supercooling channel 31 , the ejection amount of the cooling medium of the corresponding first jet hole 41 can be controlled, thereby accurately adjusting the cooling effect of various parts of the drill tip 1 .

[0069] Further, if 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 relationship: Tk = 0.68Ds - 0.554, 0.08Ds ≤ d ≤ 0.7Ds. It should be noted that the above 0.554 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 in directing the cooling medium through the supercooling channel 31 and an inability to 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, and thus making it difficult to manufacture the micro drill bit 100. By ensuring that the radial dimension d of the supercooling channel 31 satisfies the corresponding relationship, the radial dimension of the supercooling channel 31 can be made as large as possible, thereby increasing the flow rate of the cooling medium within the supercooling channel 31 and achieving a better cooling effect on the drill tip 1.

[0071] like Figure 9 As shown, in some embodiments of the present 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 process of machining the micro drill bit 100, the first jet hole 41 is extended in the opposite 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, machining equipment is used to form the jet hole from the intersection 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 extended section of the first jet hole 41, thereby allowing the first jet hole 41 to be machined and formed. In some embodiments of the present application, the orifice of the extended section can also serve as an inlet.

[0072] like Figure 10 As shown, in some embodiments of the present application, when a supercooling channel 31 is provided in the drill shank 3 and a plurality of 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 through the cold channel 31 and the at least one first jet hole 41, so that the supercooling channel 31 is simultaneously connected to the plurality of first jet holes 41. Furthermore, 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 wall of the drill shank 3, the opening of the auxiliary channel 32 on the outer wall of the drill shank 3 needs to be sealed after the auxiliary channel 32 is connected to the cold channel 31 and the corresponding first jet hole 41. The sealing methods of the opening of the auxiliary channel 32 on the outer wall of the drill shank 3 include but are not limited to glue sealing, plastic sealing, welding additional materials, etc. Figure 2 As shown, in some embodiments of the present application, the end of the drill tip 1 away 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 during the initial drilling process 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 and is used for the main drilling work, removing material from the workpiece through drilling 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 is provided on the flank surface of the sub-cutting edge. Preferably, the junction of any two adjacent sub-cutting edges is provided with a transition surface 11. By providing the transition surface 11 at the junction of two adjacent sub-cutting edges, a smooth transition between the two adjacent sub-cutting edges can be achieved, thereby reducing the drilling resistance at the junction of the two adjacent sub-cutting edges, and thereby minimizing the breakage of the main cutting edge 14.

[0075] Furthermore, the outer diameter of the drill tip 1 gradually increases in the direction from the drill tip 1 to the drill body 2. In order 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 provided at the connection between the drill tip 1 and the outer periphery of the drill body 2 can make the hole wall formed by the drill tip 1 smoothly transition to contact with the drill body 2, thereby reducing the rigid impact on the drill body 2 and reducing the working resistance of the micro drill 100, thereby improving the stability of the micro drill 100 during operation. In addition, the transition surface 11 can improve the distribution position of the cutting heat generated by the micro drill 100 during operation, thereby avoiding local overheating of the micro drill 100 and slowing down the heating rate of the micro drill 100. Further, as Figure 4-Figure 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, electrospark machining, or chemical etching. By providing the microtexture 12 on the transition surface 11 at the edge of the drill tip 1, and arranging the multiple microgrooves 121 on the microtexture 12 in a predetermined direction, the microtexture 12 can guide the flow of chips when the chips generated by the drill tip 1 contact the transition surface 11, thereby improving the problem of chip accumulation and secondary cutting within the hole. Furthermore, the microgrooves 121 are recessed toward the inside of the drill tip 1, which reduces the contact area between the drill bit and the chips, thereby reducing the friction force on the drill tip 1. Compared with the prior art, the waste chips generated by the microdrill bit 100 can be promptly discharged from the hole, thereby slowing the drill bit's temperature rise and reducing the wear rate of the microdrill bit 100. This can improve the processing quality of the hole structure and extend the service life of the microdrill bit 100.

[0076] In addition, cutting fluid can be stored in the micro-grooves 121. When the transition surface 11 contacts the workpiece, the cutting fluid in the micro-grooves 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 100.

[0077] In some specific embodiments, the sub-cutting edge farthest from the chisel edge 13 among the multiple sub-cutting edges of each main cutting edge 14 is provided with a cutting edge band between the micro-texture 12 and the cutting edge of each sub-cutting edge to ensure the strength of the cutting edge and the guiding effect of the cutting direction of the cutting edge. When the main cutting edge 14 is separated from the formed hole wall, the micro-texture 12 can cut off the chips at the separation point, thereby making the main cutting edge 14 separate from the hole wall smoother.

[0078] In some embodiments, 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 the first cutting edge 122 is connected to the chip groove 21, so that the connection between the first cutting edge 122 and the chip groove 21 forms a secondary cutting edge, and the transition surface 11 at the connection between the drill tip 1 and the drill body 2 is set on the first cutting edge 122. Combined with the cutting edges between the micro texture 12 and the cutting edge on each transition surface 11, when the micro drill bit 100 drills to form a hole structure, each cutting edge can contact the hole wall, thereby realizing a supporting effect on the micro drill bit 100, so that the micro drill bit 100 can perform hole processing more stably.

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

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

[0081] The transition plane can be formed by chamfering the connection between the drill tip 1 and the drill body 2, and the transition plane is inclined toward the inner side of the micro drill bit 100 in the direction from the drill body 2 to the drill tip 1. By constructing the transition surface 11 as a transition plane, when the micro drill bit 100 drills to form a hole structure, the planar 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 further reducing the resistance encountered by the micro drill bit 100 at the transition surface 11.

[0082] By constructing the transition surface 11 as an obtuse-angle transition surface 11, the obtuse-angle transition surface 11 is composed of two planes with an obtuse angle between them. The angle formed by the two planes protrudes toward the outside of the drill tip 1. One of the two planes is connected to the edge of the drill body 2, and the other is connected to the drill tip 1. When the micro drill bit 100 drills a hole structure, the obtuse-angle transition surface 11's avoidance effect on the hole wall curve 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-angle transition surface 11 can assist the drill tip 1 in drilling the hole structure. As a result, users can select the appropriate transition surface 11 structure based on the specific usage scenario to meet the processing requirements of the hole structure.

[0083] In some embodiments of the present application, the microgrooves 121 are arranged in multiple rows, including multiple rows and multiple columns and multiple rows and single columns. 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 configured as hole-shaped microgrooves 121 or strip-shaped microgrooves 121. The microgrooves 121 configured as strip-shaped microgrooves 121 extend 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 use requirements of different types of micro drill bits 100 can be met.

[0084] Specifically, if Figure 4 As shown, the arrangement of the plurality of micro grooves 121 is a multi-row and multi-column arrangement, and the micro grooves 121 are constructed as the above-mentioned porous 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] Moreover, the aperture size of the porous micro-grooves 121 in the longitudinal direction of the transition surface 11 is not greater than the spacing distance between two adjacent porous micro-grooves 121 in the longitudinal direction of the transition surface 11, and the aperture size of the porous micro-grooves 121 in the transverse direction of the transition surface 11 is not greater than the spacing distance between two adjacent porous micro-grooves 121 in the transverse direction of the transition surface 11.

[0086] By reducing the distance between two adjacent porous micro-grooves 121 in the longitudinal direction of the transition surface 11 and correspondingly reducing the aperture size of the porous micro-grooves 121 in the longitudinal direction of the transition surface 11, the transition surface 11 can accommodate a larger number of micro-grooves 121 in the longitudinal direction. Correspondingly, by reducing the distance between two adjacent porous micro-grooves 121 in the transverse direction of the transition surface 11 and correspondingly reducing the aperture size of the porous micro-grooves 121 in the transverse direction of the transition surface 11, the transition surface 11 can accommodate a larger number of micro-grooves 121 in the transverse direction.

[0087] The specific aperture sizes of the porous micro-grooves 121 in the horizontal and vertical directions can be set according to the actual usage scenario, for example, according to the structural size of the micro drill 100, the area of the transition surface 11, etc. Figure 4 (1) Figure 4 (2) shows two specific implementations of multiple porous micro-grooves 121 arranged in multiple rows and columns, wherein: Figure 4 (1) is a schematic diagram of the porous micro-grooves 121 being arranged on the transition plane. Figure 4 (2) is a schematic diagram of the porous micro-grooves 121 being arranged on the obtuse angle transition surface.

[0088] In some preferred embodiments, the porous micro-grooves 121 can be arranged on the transition surface 11 with a smaller area. By constructing the micro-grooves 121 as porous micro-grooves 121, the number of micro-grooves 121 on the transition surface 11 can be effectively increased, and the micro-grooves 121 can make full use of the surface space of the transition surface 11, so that the micro-texture 12 has a larger chip removal space, and the micro-texture 12 can better guide the flow of chips, thereby improving the chip accumulation and secondary cutting problems in the hole.

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

[0090] Furthermore, the micro grooves 121 are constructed as the aforementioned strip-shaped micro grooves 121 , which extend along the horizontal direction of the transition surface 11 , that is, the aperture size of the transition surface 11 in the horizontal direction is larger than that in the vertical direction.

[0091] At the same time, if Figure 5 As shown, the aperture size of the strip micro-grooves 121 in the longitudinal direction of the transition surface 11 is not greater than the spacing between two adjacent strip micro-grooves 121 in the longitudinal direction of the transition surface 11. By reducing the spacing between two adjacent strip micro-grooves 121 in the longitudinal direction of the transition surface 11 and correspondingly reducing the aperture size of the strip micro-grooves 121 in the longitudinal direction of the transition surface 11, such an arrangement can allow the transition surface 11 to accommodate a greater number of micro-grooves 121 in the longitudinal direction. The specific aperture size of the strip micro-grooves 121 in the longitudinal direction of the transition surface 11 can be set according to the actual usage scenario, for example, according to the structural size of the micro drill 100, the area of the transition surface 11, etc. Figure 5 (1) and Figure 5 (2) shows two specific implementations of the strip micro-grooves 121 of the above embodiment arranged in a single row and multiple columns, wherein: Figure 5 (1) is a schematic diagram of the strip-shaped micro-grooves 121 being arranged on the transition plane. Figure 5 (2) is a schematic diagram of the strip-shaped micro-grooves 121 being arranged on the obtuse-angle transition surface.

[0092] In some preferred embodiments, the strip-shaped microgrooves 121 of the above-described embodiment can be arranged on a transition surface 11 of medium area. By configuring the microgrooves 121 as the strip-shaped microgrooves 121 of the above-described embodiment, the outer peripheral wall of the drill body 2 is provided with a continuous first land 122. When the linear microgrooves 121 cooperate with the first land 122 and the first land 122 contacts the hole wall, machining marks and cutting marks on the hole structure can be reduced. The microtexture 12 on the transition surface 11 at the junction of each sub-cutting edge and the land between the microtexture 12 and the cutting edge have the same effect and are not further described here.

[0093] like Figure 6 As shown, in some other embodiments of the present application, the aperture size of the strip micro-grooves 121 in the longitudinal direction of the transition surface 11 is not greater than the spacing between two adjacent strip micro-grooves 121 in the longitudinal direction of the transition surface 11. In other words, the strip micro-grooves 121 can have a larger aperture size in the longitudinal direction of the transition surface 11, and each strip micro-grooves 121 occupies a larger space on the transition surface 11. The specific aperture size of the strip micro-grooves 121 in the longitudinal direction of the transition surface 11 can be set according to the actual use scenario, for example, according to the structural size of the micro drill 100, the area of the transition surface 11, etc. Figure 6 (1) Figure 6 (2) shows two specific implementations of the strip micro-grooves 121 of the above embodiment arranged in a single row and multiple columns, wherein: Figure 6 (1) is a schematic diagram of the strip-shaped micro-grooves 121 being arranged on the transition plane. Figure 6 (2) is a schematic diagram of the strip-shaped micro-grooves 121 being arranged on the obtuse-angle transition surface.

[0094] In some preferred embodiments, the strip-shaped micro-grooves 121 of the above-mentioned embodiment can be arranged on a transition surface 11 with a larger area. By constructing the micro-grooves 121 as the strip-shaped micro-grooves 121 of the above-mentioned embodiment, the strip-shaped micro-grooves 121 of the above-mentioned embodiment have good rigidity, and the strip-shaped micro-grooves 121 of the above-mentioned embodiment have a sufficiently large contact area with the hole wall, which can reduce the problem of chipping of the micro drill bit 100 during drilling processing, thereby enabling the micro drill bit 100 to process difficult-to-process materials such as high hardness and high toughness, thereby improving the product performance of the micro drill bit 100.

[0095] It should be understood that the aforementioned smaller, medium, and larger areas represent the relative area sizes of the transition surface 11 and do not represent the actual area sizes. Since micro drills 100 of different sizes have different transition surfaces 11, the type of micro grooves 121 can be set according to the actual use of the micro drill 100. Figure 4-Figure 6The arrangement of the micro-grooves 121 shown only provides some feasible embodiments of the present application, but the present application is not limited thereto. The specific arrangement of the micro-grooves 121 can be set according to the actual production conditions of the micro drill 100 .

[0096] like Figure 10-14 As shown, in some specific embodiments of the present application, a supercooling channel 31 is coaxially arranged with the drill shank 3, one end of the supercooling channel 31 extends into the drill body 2, and a second jet hole 22 is formed on the outer peripheral wall of the drill body 2. The second jet hole 22 is connected to the supercooling channel 31, and the supercooling channel 31 is suitable for connecting to an external cold source. After the external cold source provides cooling medium into the supercooling channel 31, the cooling medium can flow out of 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 accelerating wear due to excessive operating temperature. In addition, part of the cooling medium can cool the environment surrounding the drill body 2, thereby reducing the temperature of the environment surrounding the drill body 2, thereby improving the thermal conductivity of the heat dissipated from the drill tip 1.

[0097] Furthermore, by extending the supercooling channel 31 into the drill body 2, the coolant flowing along the supercooling channel 31 cools the drill body 2, thereby preventing overheating of the drill body 2. This arrangement also shortens the distance between the second jet hole 22 and the drill tip 1 along the axial direction of the microdrill bit 100, allowing the coolant to more precisely cool the drill tip 1, further enhancing the cooling effect of the microdrill bit 100. Furthermore, by separating the supercooling channel 31 from the chip flute 21, the supercooling channel 31 is minimized from affecting the strength of the portion of the drill body 2 where the chip flute 21 is located, thereby preventing the drill body 2 from breaking during operation.

[0098] like Figure 11 、 Figure 13 、 Figure 14 As shown, in some embodiments of the present application, the opening of the second jet hole 22 in the outer peripheral wall of the drill body 2 is located outside the chip groove 21. By arranging the opening of the second jet hole 22 outside the chip groove 21, when the cooling medium is ejected 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, and the cooling medium can also be sprayed onto the hole wall of the hole structure. The cooling medium can simultaneously cool the hole wall to reduce the temperature of the hole wall and improve the processing 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 groove 21 along the axial direction of the drill body 2 to achieve the technical effect of the second jet hole 22 being located outside the chip 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 groove 21 (i.e., the back of the micro drill bit 100), so as to achieve the technical effect of the second jet hole 22 being located outside the chip groove 21.

[0100] like Figure 11-14 As shown, in some embodiments of the present application, the supercooling channel 31 includes a plurality of sequentially connected supercooling subchannels 311. The radial dimensions of any two adjacent supercooling subchannels 311 gradually decrease as they move from the drill shank 3 to the drill tip 1. By gradually reducing the radial dimensions of the supercooling subchannels 311, the amount of drill material required to be removed from the microdrill 100 to machine the supercooling subchannels 311 can be gradually reduced as they move from the drill shank 3 to the drill tip 1. This ensures that the microdrill 100 meets rigidity design requirements, reduces jitter during operation, and improves the machining accuracy of the microdrill 100.

[0101] like Figure 11-14 As shown, in some embodiments of the present application, the radial dimension of the nth subcooling subchannel 311, from the end of the subcooling channel 31 away from the chip flute 21 to the end closer to the chip flute 21, 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 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 disposed within the drill shank 3, and the second through nth subcooling subchannels 311 are disposed within 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, thereby affecting the flow rate of the cooling medium in subsequent subcooling subchannels 311. When the radial dimension dr1 of the first supercooling subchannel 311 is greater than 0.2 times the diameter dimension Ds of the drill shank 3 , the first supercooling subchannel 311 will affect the rigidity of the drill shank 1 .

[0102] When the radial dimension drn of the second to nth subcooling subchannels 311 311 is less than 0.1 times the diameter D of the drill body 2 , the flow capacity of the second to nth subcooling subchannels 311 311 is poor, thereby affecting the jet flow rate of the second jet hole 22 . When the radial dimension drn of the second to nth subcooling subchannels 311 311 is greater than 0.8 times the diameter D of the drill body 2 , the second to nth subcooling subchannels 311 311 may affect the rigidity of the drill body 2 .

[0103] By making the radial dimension of the nth supercooling sub-channel 311 satisfy the above relationship, the micro drill 100 can be ensured to meet the rigidity design requirements while increasing the flow area of each supercooling sub-channel 311 as much as possible.

[0104] Furthermore, the aperture size 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, where D and Ω satisfy the relationship: 0.1D≤d1≤0.7D, 2°≤Ω<90°. When the aperture size of the second jet hole 22 is too small, the flow rate of the cooling medium at the open mouth of the second jet hole 22 is too small, which will cause the cooling efficiency of the micro drill bit 100 to be too low, and the temperature at the drill tip 1 is prone to be too high and wear is accelerated. When the aperture size of the second jet hole 22 is too large, too much drill material needs to be removed to machine the second jet hole 22 on the drill body 2, resulting in the micro drill bit 100 not meeting the rigidity design requirements. Therefore, by making the aperture size of the second jet hole 22 satisfy the above-mentioned relevant relationship, the micro drill bit 100 can achieve both 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 effectively cool the periphery of the drill body 2, and the second jet hole 22 is difficult to form 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 effectively 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 is ensured that the second jet hole 22 can effectively cool the drill tip 1 of any model of micro drill bit 100.

[0106] like Figure 15-17 As shown, in some embodiments of the present application, the main cutting edge 14 includes one or more sub-cutting edges. In the main cutting edge 14 having multiple sub-cutting edges, the multiple sub-cutting edges are connected in sequence, and there is an 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 toward the outside of the drill tip 1, during the drilling process of the micro drill bit 100, the spacing distances between different positions of the main cutting edge 14 and the central axis of the micro drill bit 100 are different, that is, the main cutting edge 14 is subjected to different torques at different positions. Specifically, the torque exerted on the main cutting edge 14 at a position close to the central axis of the micro drill bit 100 is greater than the torque exerted on the position away from the central axis of the micro drill bit 100.

[0108] By dividing the main cutting edge 14 into multiple sub-cutting edges, the multiple sub-cutting edges can drill the workpiece material in segments. The cutting edges of the multiple sub-cutting edges evenly distribute the torque applied to the main cutting edge 14, thereby ensuring uniform wear on the main cutting edge 14 and thereby increasing the service life of the drill bit. Of course, in some embodiments, if the workpiece material being drilled by the micro drill bit 100 is relatively hard, by configuring the main cutting edge 14 as a single sub-cutting edge, i.e., not segmenting the main cutting edge 14, while still meeting the drilling requirements of the micro drill bit 100, this can reduce the difficulty of machining the micro drill bit 100, thereby reducing the production cost of the micro drill bit 100.

[0109] In some embodiments of the present application, the drill tip 1 has a plurality of main cutting edges 14, wherein the drill tip 1 is generally provided with two main cutting edges 14, but in some embodiments, for example Figure 22 As shown, the drill tip 1 can also be provided 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 the micro drill 100 is used to drill a workpiece, the three main cutting edges 14 cut into the workpiece at the same time. Compared with the micro drill 100 with two main cutting edges 14, the micro drill 100 with three main cutting edges 14 has a smaller cutting load borne by each main cutting edge 14, so the drilling process of the micro drill 100 can be made smoother. In addition, since the three main cutting edges 14 of the micro drill 100 are involved in cutting at the same time, the cutting force is more evenly distributed in three directions. This uniform force distribution method helps to reduce the working vibration and offset of the main cutting edge 14, thereby improving the processing stability of the micro drill 100.

[0110] In addition, the micro drill 100 having three main cutting edges 14 is also provided with three chip flutes 21. The three chip flutes 21 can collectively divide the chips into smaller structures, and the chips can be effectively discharged out of the hole through the chip flutes 21. Therefore, the micro drill 100 having three main cutting edges 14 is suitable for deep hole machining, thereby effectively preventing chip blockage in the hole and further reducing the temperature of the drill tip 1 of the micro drill 100.

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

[0112] When the main vertex angle θ is too small, the length of the cutting edge increases, and the area of contact between the cutting edge and the workpiece increases, which can reduce the axial cutting force of the micro drill bit 100 and make cutting heat more easily transferred and dissipated. At the same time, it can reduce the strength and wear resistance of the micro drill bit 100. Conversely, when the main vertex angle θ is too large, the length of the cutting edge decreases, and the area of contact between the cutting edge and the workpiece decreases. This can increase the axial cutting force of the micro drill bit 100, make cutting heat less easily transferred and dissipated, and at the same time increase the strength and wear resistance of the micro drill bit 100.

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

[0114] like Figure 15 As shown, in some other embodiments of the present 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 respectively 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 in sequence to form the main cutting edge 14.

[0115] Furthermore, there are two embodiments for designing the angles 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. 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 a first vertex angle θ1, the angle between the projections of any two adjacent second sub-cutting edges 142 in the mid-section is a second vertex angle θ2, and in the same mid-section, the angle between the projections of two adjacent third sub-cutting edges 143 in the corresponding mid-section is a third vertex angle θ3, the first proportional coefficient is K1, K1, θ1, θ2 and θ3 satisfy the relationship: 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 them into the above equation, we obtain a second vertex angle θ2 of 90° and a third vertex angle θ3 of 60°. This means that the micro drill bit 100 can form a cutting force attenuation gradient of 130°-90°-60° in the axial direction. In this case, 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 bit 100, and the third sub-cutting edge 143 can trim the hole wall. Furthermore, when θ1 is 110°, the micro drill bit 100 can form a cutting force attenuation gradient of 110°-30°-K1*30° in the axial direction. Since θ2>θ3, K1 is 0.4≤K1<1 at this time. The micro drill bit 100 can also form a cutting force attenuation gradient with gradually decreasing angles in the axial direction, thereby achieving uniform distribution of cutting force. When θ1 is 160°, the micro drill bit 100 can form a cutting force attenuation gradient in the axial direction of 160° - 30° - K1 * 30°. Since θ2 > θ3, and K1 is 0.4 ≤ K1 < 1, the micro drill bit 100 can also form a cutting force attenuation gradient with gradually decreasing angles in the axial direction, achieving uniform distribution of cutting force. Therefore, in the first gradual change mode, when 110° ≤ θ1 ≤ 160°, 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 a first vertex angle θ1, the angle between the projections of any two adjacent second sub-cutting edges 142 in the mid-section is a second vertex angle θ2, and the angle between the projections of any two adjacent third sub-cutting edges 143 in the mid-section is a third vertex angle θ3. The second proportional coefficient is K2, and θ1, θ2, and θ3 satisfy the relationship: 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 them into the above equation, the second vertex angle θ2 is calculated to be 88°, and the third vertex angle θ3 is calculated to be 116°. This means that the microdrill 100 can form a cutting force attenuation gradient of 130°-88°-116° in the axial direction. In this case, 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 microdrill 100, and the third sub-cutting edge 143 can increase the rigidity of the hole wall. Furthermore, when θ1 is 110°, the microdrill 100 can form a cutting force attenuation gradient of 110°-30°-K2*30° in the axial direction. Since θ2 < θ3, and K2 is 1 < K2 ≤ 1.5, the microdrill 100 can also form a cutting force attenuation gradient in the axial direction where the angle first decreases and then increases, achieving uniform distribution of cutting force. When θ1 is 160°, the microdrill 100 can form a cutting force attenuation gradient in the axial direction of 160° - 30° - K2 * 30°. Since θ2 < θ3, and K2 is 1 < K2 ≤ 1.5, the microdrill 100 can also form a cutting force attenuation gradient in the axial direction where the angle first decreases and then increases, achieving 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 angles between the multiple sub-cutting edges of the main cutting edge 14, the micro drill can meet different hole structures and material processing requirements.

[0121] like Figure 15 As shown, in some embodiments of the present 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 away 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 Satisfy the relationship: 0.2D≤R 1a ≤0.325D, 0.325D<R 2a ≤0.425D, 0.425D<R 3aThus, by providing the connection between two adjacent sub-cutting edges at a 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 of the connection between the two adjacent sub-cutting edges, thereby extending the service life of the micro drill bit 100.

[0122] In some embodiments provided in the present application, those skilled in the art can easily conceive that the drill tip can be set to 1, 2, 3 or more drill tip apex angles based on the embodiments provided in the present application.

[0123] Furthermore, if Figure 16 As shown, the drill tip 1 is also provided with a main flank 15, which is located behind the main cutting edge 14, and a clearance angle φ is formed between the tangent surface of the main cutting edge 14 and the main flank 15. In the direction from the chisel edge 13 to the chip groove 21, the first sub-cutting edge 141 has two clearance angles 17, and the second sub-cutting edge 142 and the third sub-cutting edge 143 each have a clearance angle 17, where the angle of the clearance angle 17 is represented as φ. By increasing the number of clearance angles 17 of the first sub-cutting edge 141, the air avoidance effect of the first sub-cutting edge 141 can be improved, and 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 making the second sub-cutting edge 142 and the third sub-cutting edge 143 respectively have a clearance 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 back angles φ1, a back angle φ 11 The range is 1°-20°, preferably 5°-20°, and the clearance angle φ of the first sub-cutting edge 141 away from the clearance surface of the first sub-cutting edge 141 is 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 is in the range of 10°-50°, preferably 10°-25°; the back angle φ3 of the drill tip 1 where the third sub-cutting edge 143 is located is in the range of 10°-50°, preferably 10°-25°.

[0125] The drill tip clearance angle increases the air clearance and cutting edge sharpness of the micro drill bit 100, enabling it to cut materials better. The drill tip clearance angle is divided into a plane clearance angle and an arc clearance angle. When processing low-hardness and easy-to-process materials, a plane clearance angle is generally used, and the G01 straight drilling method is used for processing. It has a sharp cutting edge and better cutting force, and is suitable for high-speed processing. When processing high-hardness and difficult-to-process materials, an arc clearance angle is generally used, and the G83 pecking drilling method is used for processing. The cutting edge has better rigidity and wear resistance, and is suitable for high-intensity processing. When selecting the value of the clearance angle size, a larger clearance angle is used when processing low-hardness and easy-to-process materials, and the G01 straight drilling method is used for processing. It has a sharp cutting edge and better cutting force, and is suitable for high-speed processing. A smaller clearance angle is used when processing high-hardness and difficult-to-process materials, and the G83 pecking drilling method is used for processing. The cutting edge has better rigidity and wear resistance, and is suitable for high-intensity processing. The range of clearance angle values is based on the material being processed. For example, when processing silicon carbide, which has a Vickers hardness of 2448.96HV and is a high-hardness and difficult-to-process material, and is processed using G83, the range of clearance angle values should be adapted to reduce the first drill tip clearance angle to 8°~12°, and the first drill tip clearance angle to 25°~35°. The appropriate range of values will extend the life of the drill bit and improve 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 back angles 17. Compared with setting one back angle 17, such a setting can improve the air avoidance effect of the first sub-cutting edge 141, and can further reduce the contact between the first sub-cutting edge 141 and the hole wall, thereby further reducing the torque applied to the first sub-cutting edge 141, and can further slow down the wear rate of the first sub-cutting edge 141.

[0127] Furthermore, if Figure 16 As shown, Figure 16 (1) Schematic diagram of the back angle 17 of the main cutting edge 14 when the main cutting edge 14 includes three sub-cutting edges. Figure 16 (2) is another embodiment of the present application, in which the main cutting edge 14 includes two sub-cutting edges, and a schematic diagram of the back angle 17 of the main cutting edge 14 is shown.

[0128] Figure 16 (3) Schematic diagram of the back angle 17 of the main cutting edge 14 when the main cutting edge 14 includes a sub-cutting edge.

[0129] like Figure 17 As shown, in some embodiments of the present application, the back surface of the first sub-cutting edge 141 is provided with a second edge band 23, and the second edge band 23 is suitable for abutting against the hole wall of the hole structure to provide radial support for the drill body 2, and the second edge band 23 can disperse the distribution of the drilling force of the micro drill bit 100 to avoid excessive concentration of the drilling force of the micro drill bit 100, which may cause the micro drill bit 100 to be easily damaged.

[0130] A chamfered surface 6 connects the first sub-cutting edge 141 and the second land 23. This chamfered surface 6 redirects chip flow near the main cutting edge 14, thereby reducing friction and wear between the microdrill 100 and the workpiece, helping to extend the drill's service life. It also reduces cutting heat generation, thereby strengthening the structural strength of the main cutting edge 14. A plane perpendicular to the central axis of the microdrill 100 serves as an auxiliary plane. 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 land 23 is Dx, and the chamfer angle is γ. Dx and γ satisfy the relationship: 0.07D ≤ Dx ≤ 0.13D, 2° ≤ γ ≤ 7°. By properly sizing the width and chamfer angle of the second land 23, problems such as chipping can be minimized in the microdrill 100.

[0131] like Figure 18 As shown, in some embodiments of the present application, the chip groove 21 includes a spiral groove and a straight groove connected to each other. The spiral 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 spiral groove is provided with a secondary cutting edge, which is used to assist in drilling the hole structure. The straight groove is provided at the end of the spiral 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 rear end of the chip groove 21, can reduce the runout of the drill body 2 during operation, and thus can improve the processing accuracy of the micro drill bit 100.

[0132] A first crushing structure 5 is provided within the chip flute 21. The first crushing structure 5 extends from the end of the straight flute away from the drill tip 1 toward the drill tip 1. The first crushing structure 5 is formed by a plurality of first crushing flutes 51 arranged in an array. In other words, the first crushing structure 5 can be composed of a plurality of first crushing flutes 51 in a single row or multiple columns, or a plurality of first crushing flutes 51 in multiple rows or multiple columns. Before the chips in the chip flute 21 are discharged from the chip flute 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 flute 21.

[0133] like Figure 18 As shown, in the axial direction of the micro drill bit 100, the chip flute 21 has a length L along the axial direction of the micro drill bit 100, 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 axial length of the first crushing structure 5 along the micro drill bit 100 is too small, the first crushing structure 5 will not be able to fully crush the chips, resulting in excessively large chips and difficulty in discharging the chips from the chip flute 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 chips will be too small after being crushed by the first crushing structure 5 before being discharged from the chip discharge flute 21. The chips will easily accumulate in the hole structure, which will easily affect the processing quality of the hole structure and increase the heating rate of the micro drill bit 100. By positioning the end of the first crushing structure 5 near the drill tip 1 (i.e., the starting point of the first crushing structure 5) at 0.6 to 0.7 times the length of the drill body 2, the chips can be crushed to a more appropriate size by the first crushing structure 5, thereby facilitating the discharge of chips generated in the hole structure along the chip discharge flute 21 and out of the hole structure.

[0135] Furthermore, if Figure 18 As shown, the first crushing structure 5 can be formed by a combination of a plurality of first crushing grooves 51 arranged in an array and a plurality of first crushing grooves 51 arranged in an array. The first crushing grooves 51 are arranged on the side of the first crushing grooves 51 close to the drill tip 1. The distance between the first crushing grooves 51 and the first crushing grooves 51 is 0.03D to 0.04D, where D is the diameter of the drill body 2. Figure 19 As shown, the width dimension t, the groove depth dimension h, and the angle ω between the groove bottom and the groove wall of the second crushing groove satisfy the relationship: t=0.0053D+0.0147, h=0.014D-0.006, 0≤ω≤90°.

[0136] In some embodiments of the present application, the chip groove 21 includes a plurality of sub-chip grooves 211 connected in sequence along the axial direction of the drill body 2, and at least two sub-chip grooves 211 have different groove shapes. The chip removal capabilities (such as chip removal speed, guiding direction of metal debris) of the sub-chip grooves 211 with different groove shapes are different. By arranging appropriate sub-chip grooves 211 in different areas of the drill body 2, and then connecting multiple sub-chip grooves 211 in sequence, when the chips are discharged to the outside of the hole structure along the multiple sub-chip grooves 211 in sequence, the cooperation of the multiple sub-chip grooves 211 can improve the chip removal smoothness of the chip groove 21, so that the chips can be discharged from the hole structure in time, and then the chips can be prevented from accumulating in the hole structure.

[0137] In addition, the cross-sectional shapes of the drill body 2 corresponding to the sub-chip grooves 211 of different groove types are different. For example, the outer peripheral wall of the drill body 2 is provided with two chip grooves 21. Figure 20 A cross-sectional view of the drill body 2 of the present application at the sub-chip grooves 211 of different groove types is shown, wherein the groove types of the multiple chip grooves 21 of the drill body 2 are consistent, 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 flutes 211 disclosed in this application. Specifically, each sub-chip flute 211 of different flute types is constructed as a symmetrical structure, and the symmetry axis of each sub-chip flute 211 passes through the central axis of the micro drill 100.

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

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

[0140] By combining a plurality of sub-chip flutes 211 , the rigidity of the drill body 2 can be improved, thereby reducing the vibration of the drill body 2 when machining a workpiece, and further improving the machining accuracy of the micro drill 100 .

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

[0142] As shown in the following table, the table shows the calculated values of the maximum number N of the sub-chip grooves 211 when the length dimension L of the chip groove 21 along the axial direction of the micro drill 100, the diameter dimension D of the drill body 2, and the ratio A of the length dimension of the chip groove 21 to the diameter dimension of the drill body 2 are different values.

[0143] A L N <![CDATA[1<A1≦5]]> <![CDATA[D<L1≤5D]]> 3 <![CDATA[5<A2≦10]]> <![CDATA[5D<L2≤10D]]> 4 <![CDATA[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] Further, if Figure 21 As shown, the number of sub-chip grooves 211 located at the drill tip 1 is one, and the length dimension of the sub-chip groove 211 located at the drill tip 1 along the axial direction of the micro drill bit 100 is P1. The length dimensions of each sub-chip groove 211 located at the drill body 2 along the axial direction of the micro drill bit 100 are consistent, and the length dimension of each sub-chip groove 211 located at the drill body 2 along the axial direction of the micro drill bit 100 is P2. P1, P2, L and N satisfy the relationship: P2 = (L-P1) / (N-1).

[0145] As shown in the following table, the maximum number N of the sub-chip grooves 211 is shown in different values, and the length P of each sub-chip groove 211 along the axial direction of the micro drill 100 is shown in the following table. n .

[0146]

[0147]

[0148] Further, based on Figure 20 The various groove types of the sub-chip grooves 211 shown in the table below show different combinations of the groove types of the sub-chip grooves 211 when the chip groove 21 includes multiple sub-chip grooves 211 and at least two sub-chip grooves 211 have different groove types. It should be noted that type (1), type (2) ... type (n) in the table correspond to Figure 20 Medium (1) type, (2) type...(n) type.

[0149]

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

[0151] like Figure 2 and Figure 20As shown, in some embodiments of the present application, the main flank 15 is provided with a tooth gap 151 that is recessed toward the drill shank 3. The tooth gap 151 is connected to the chip groove 21, and the tooth gap 151 extends from the chisel edge 13 to the outer circle of the drill tip 1. A smoothly transitioned chamfered surface is provided between the tooth gap 151 and the flank of the sub-cutting edge farthest from the drill tip. When the tooth gap 151 is formed on the main flank 15, part of the chisel edge 13 ( Figure 20 The middle chisel edge is not shown), and at the same time, a sub-cutting edge is added to the main cutting edge 14 adjacent to the main flank face 15, and the 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, and the fourth sub-cutting edge 144 is mainly used to cut off the debris, so that the debris can be smoothly discharged to the chip groove 21 of the drill body 2 through the tooth gap 151, and will not be 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 ability of the flank face is improved. The flank surface of the last sub-cutting edge of the main flank face 15 and the connecting portion of the tooth gap form a chamfered surface 16. The chamfered surface 16 can be formed by removing part of the structure of the main flank face 15. The transition between the chamfered surface 16 and the tooth gap 151 can be achieved by a circular arc transition. The provision of the chamfered surface 16 can form an air gap between the tooth gap 151 and the main flank face 15, thereby improving the fluidity of the chips and thus reducing the problem of chip accumulation in the hole structure. To further improve the chip removal capability, a second jet hole 22 can also be provided in the tooth gap to further enhance the cooling, lubrication and chip removal capabilities of the drill tip.

[0152] In some embodiments of the present application, Figure 23 and 24 As shown, in order to improve the chip holding and chip removal function of the micro drill 100 during processing, a tooth gap 151 is set on the back cutting edge of the drill tip 1, and the tooth gap 151 includes: tooth gap chip groove angle η1, value range: 25°~70°; tooth gap offset angle η2, value range: 20°~50°; tooth gap expansion angle η3, value range: 50°~90°. Among them, the larger the tooth gap chip groove angle η1, the larger the chip removal space, which is suitable for easy-to-process materials; the smaller the tooth gap chip groove angle η1, the better the rigidity of the drill tip 1, which is suitable for difficult-to-process materials; the larger the tooth gap offset angle η2, the shorter the cutting edge, the smaller the chip removal space, the better the rigidity of the drill tip 1, which is suitable for difficult-to-process materials; the smaller the tooth gap offset angle η2, the longer the cutting edge, the larger the chip removal space, the faster the processing efficiency, which is suitable for easy-to-process materials; the larger the tooth gap expansion angle η3,

[0153] A larger chip clearance is suitable for easier-to-machine materials, while a smaller tooth gap angle η3 increases the rigidity of the drill tip 1, making it suitable for difficult-to-machine materials. Furthermore, the tooth gap 151 of the drill tip 1 is designed to optimize stress distribution, thereby preventing stress concentration and enhancing the durability of the micro drill bit 100.

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

[0155] An embodiment of the present application also provides a processing device, including a driving device, a clamping device and the micro drill 100 of the aforementioned embodiment. The clamping device clamps the micro drill 100, and the driving device drives the micro drill to rotate through the clamping device to achieve processing of the workpiece.

[0156] According to the processing equipment of the present 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 set 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 to 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 is only a preferred embodiment of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and replacements can be made without departing from the technical principles of the present application. These improvements and replacements should also be regarded as the scope of protection of the present application.

Claims

1. A micro drill, characterized in that: include: A drill tip, a drill body and a drill shank connected in sequence 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, and the chip removal groove extends from the drill tip to the drill shank; A transition portion is connected between the drill shank and the drill body, and a contour line of an outer peripheral wall of the transition portion smoothly transitions from the drill shank to the drill body; A supercooling channel is provided in the drill shank, one end of the supercooling channel extends to the transition portion, and a first jet hole is provided on an outer peripheral wall of the transition portion. The first jet hole is communicated with the supercooling channel and is open toward the drill tip. The angle between the first jet hole 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 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 angular coefficient is δ. δ, α, Tk, L1, D, Ds and β satisfy the relationship:

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

3. The micro drill according to claim 1, characterized in that A plurality of supercooling channels are provided in the drill shank, and the plurality of supercooling channels are sequentially spaced apart along the circumference of the drill shank, and each of the supercooling channels is connected to at least one of the first jet holes.

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

5. The micro drill according to claim 1, wherein: A chisel edge and a main cutting edge are provided at one end of the drill tip away from the drill body, the main cutting edge is connected between the chisel edge and the chip groove, the main cutting edge includes one or more sub-cutting edges, and, in the main cutting edge having multiple sub-cutting edges, the multiple sub-cutting edges are connected in sequence, and an angle is formed between any two adjacent sub-cutting edges of each main cutting edge.

6. The micro drill according to claim 5, characterized in that The drill tip has multiple main cutting edges to construct a mid-section passing through the central axis of the micro drill bit and 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, and θ satisfies the relationship: 110°≤θ≤160°.

7. The micro drill according to claim 5, characterized in that The drill tip has a plurality of main cutting edges, with a mid-section formed by passing through the central axis of the micro drill bit and parallel to two adjacent main cutting edges, each main cutting edge including a first sub-cutting edge, a second sub-cutting edge, and a third sub-cutting edge connected in sequence from the drill tip to the drill body, the first sub-cutting edge being connected to the chisel edge; In 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 first proportional coefficient is K1, and θ1, θ2, θ3 and K1 satisfy the relationship: 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 micro drill according to claim 5, characterized in that: The drill tip has a plurality of main cutting edges, with a mid-section formed by passing through the central axis of the micro drill bit and parallel to two adjacent main cutting edges, each main cutting edge including a first sub-cutting edge, a second sub-cutting edge, and a third sub-cutting edge connected in sequence from the drill tip to the drill body, the first sub-cutting edge being connected to the chisel edge; In 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 proportional coefficient is K2, and θ1, θ2, θ3 and K2 satisfy the relationship: 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 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 and the central axis of the micro drill is R. 1a The distance between the end of the second sub-cutting edge away from the central axis of the micro drill and the central axis of the micro drill is R 2a The distance between the end of the third sub-cutting edge away from the central axis of the micro drill and the central axis of the micro drill is R 3a , R 1a 、R 2a , and R 3a Satisfy the relationship: 0.2D≤R 1a ≤0.325D, 0.325D<R 2a ≤0.425D, R 3a =0.5D.

10. The micro drill according to claim 7 or 8, characterized in that: The drill tip is further provided with a main flank face, the main flank face being located behind the main cutting edge, and a clearance angle φ is formed between the tangent surface of the main cutting edge and the main flank face. In the direction from the chisel edge to the chip flute, the first sub-cutting edge has two clearance angles, and the second sub-cutting edge and the third sub-cutting edge each have one clearance angle. The clearance angle φ of the flank surface of the first sub-cutting edge close to 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 surface 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 is in the range of 10°-50°.

11. The micro drill according to claim 10, characterized in that: The flank surface of the first sub-cutting edge is provided with a second cutting edge, and the second cutting edge of the first sub-cutting edge is provided with a chamfered surface connected to the cutting edge. A plane perpendicular to the central axis of the micro drill bit is used as an auxiliary plane, and 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 chamfered angle is γ. Dx and γ satisfy the relationship: 0.07D≤Dx≤0.13D, 2°≤γ≤7°.

12. The micro drill according to claim 5, characterized in that The main cutting edge includes a plurality of sub-cutting edges connected in sequence, and a transition surface is provided at the connection between the flank surfaces of at least two adjacent sub-cutting edges, and / or the connection between the drill tip and the periphery of the drill body. The transition surface is provided with a micro-texture, and a cutting edge is provided between the micro-texture and the cutting edge of each sub-cutting edge. The micro-texture is formed by an array of multiple micro-grooves.

13. The micro drill according to claim 12, wherein: The drill body includes a first edge band, and a transition surface at the connection between the drill tip and the drill body is provided on the first edge band; The transition surface is constructed as an arc transition surface, a transition plane or an obtuse angle transition surface; the micro-grooves are in the shape of holes or grooves arranged in the longitudinal direction.

14. The micro drill according to claim 1, wherein: 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 side wall of the spiral groove is provided with a secondary cutting edge, and the straight groove is provided at one end of the spiral groove away from the drill tip, and the straight groove extends along the axial direction of the drill body in a direction away from the drill tip; A first crushing structure is provided in the chip groove, the first crushing structure extending from the end of the straight groove away from the drill tip toward the drill tip, and the first crushing structure is formed by a plurality of first crushing grooves arranged in an array; In the axial direction of the micro drill, the length of the chip groove is L, the distance between the end of the first crushing structure close to the drill tip and the drill tip is L2, and L and L2 satisfy the relationship: 0.6L≤L2≤0.7L.

15. The micro drill according to claim 1, wherein: The chip removal groove comprises a plurality of sub-chip removal grooves connected in sequence 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 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 groove to the diameter dimension of the drill body is A, the maximum number of the sub-chip grooves is positively correlated with the numerical value of the ratio, the maximum number of the sub-chip grooves is N, N and A satisfy the relationship: N = A / 5+2, N is an integer and is rounded up.

16. The micro drill according to claim 1, characterized in that The drill tip is further provided with a main flank surface, and the main flank surface is provided with a second crushing structure, and the second crushing structure includes a plurality of second crushing grooves arranged in sequence.

17. The micro drill according to claim 5, characterized in that The drill tip is also provided with a main flank surface and a chisel edge. The main flank surface is provided with a tooth gap recessed toward the drill shank. The tooth gap is connected to the chip groove, and the tooth gap extends from the chisel edge to the outer circle of the drill tip. A smoothly transitioned chamfered surface is provided between the tooth gap and the flank surface of the sub-cutting edge farthest from the drill tip.

18. A processing equipment, characterized in that, The micro drill comprises a driving device, a clamping device, and the micro drill according to any one of claims 1 to 17, wherein the clamping device clamps the micro drill, and the driving device drives the micro drill to rotate through the clamping device.

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