Drill bit

Abstract

According to the drill bit, due to the fact that the drill point angle of a drill point ranges from 134 degrees to 136 degrees, the front angle b of each end edge ranges from-11 degrees to-9 degrees, the rear angle c of the first end edge ranges from 11 degrees to 13 degrees, the rear angle d of the second end edge ranges from 21 degrees to 23 degrees, a chip containing groove is formed between every two adjacent end edges, and the chip containing groove has the chip containing groove angle ranging from 39 degrees to 41 degrees; therefore, in the process that the drill bit drills a machining face, resultant force towards the axis of the drill bit can be generated at the moment when the drill bit makes contact with the machining face, automatic deviation correction and self-adaptive centering of the drill bit are achieved, and the drill bit can smoothly complete drilling machining of the machining faces such as an inclined face and a curved face without pre-drilling.

Description

Technical Field

[0001] This invention relates to the field of milling tool technology, and in particular to a drill bit. Background Technology

[0002] In drilling operations in fields such as metal, wood, and composite materials, drill bits need to drill on special machined surfaces such as inclined planes and curved surfaces, or drill on workpieces with smooth and hard surfaces. However, when traditional drill bits drill on machined surfaces such as inclined planes and curved surfaces, problems such as slippage, deviation, and even tool breakage are very likely to occur.

[0003] In related technologies, before drilling on inclined or curved surfaces, it is often necessary to first drill pre-holes or perform fixed-point drilling, and then proceed with the drilling process. However, this results in more drilling steps and a more complicated drilling process. Summary of the Invention

[0004] The purpose of this invention is to at least solve one of the technical problems existing in the prior art. This invention provides a drill bit that can smoothly drill on special machining surfaces such as inclined planes and curved surfaces.

[0005] According to an embodiment of the present invention, a drill bit includes a shank and a cutting part; one end of the cutting part is connected to the shank, and the other end of the cutting part forms a drill tip. The drill tip has a drill tip angle of 134 degrees to 136 degrees. The drill tip is provided with two end cutting edges that are spaced apart circumferentially along the cutting part. A transverse cutting edge is provided between the two end cutting edges. The end cutting edges have a front angle b, a first rear angle c, and a second rear angle d. The front angle b is -11 degrees to -9 degrees, the first rear angle c is 11 degrees to 13 degrees, and the second rear angle d is 21 degrees to 23 degrees. A chip groove is formed between two adjacent end cutting edges. The chip groove has a chip groove angle of 39 degrees to 41 degrees.

[0006] The drill bit of the present invention has at least the following beneficial effects: In the drill bit of this application, since the drill tip angle is 134 degrees to 136 degrees, the rake angle b of the end cutting edge is -11 degrees to -9 degrees, the clearance angle c of the first end cutting edge is 11 degrees to 13 degrees, and the clearance angle d of the second end cutting edge is 21 degrees to 23 degrees, a chip groove is formed between two adjacent end cutting edges, and the chip groove has a chip groove angle of 39 degrees to 41 degrees. Thus, during the drilling process of the drill bit of this application on the machining surface, a resultant force is generated towards the drill bit axis at the moment the drill bit contacts the machining surface, thereby realizing automatic correction and adaptive centering of the drill bit. This allows the drill bit of this application to complete the drilling of inclined surfaces, curved surfaces and other machining surfaces without pre-drilling.

[0007] According to the drill bit of the present invention, the chisel edge angle f is 114 degrees to 116 degrees.

[0008] According to the embodiments of the present invention, the spread length L of the chisel edge of the drill bit is 1.1 mm to 1.3 mm.

[0009] According to the embodiment of the present invention, the cutting part has two peripheral cutting edges on the corresponding end edge, and a chip removal groove is formed between two adjacent peripheral cutting edges. The chip removal groove and the chip receiving groove correspond one-to-one and are connected. The peripheral cutting edge rake angle g is 15 degrees to 17 degrees.

[0010] According to the embodiment of the present invention, the drill bit has a first cylindrical ligament and a second cylindrical ligament circumferentially spaced on the back face of the peripheral cutting edge, and the width of the first cylindrical ligament is different from that of the second cylindrical ligament.

[0011] According to the drill bit of the present invention, the width of the first cylindrical ligament is 0.29 mm to 0.31 mm, and the width of the second cylindrical ligament is 0.34 mm to 0.36 mm.

[0012] According to the embodiment of the present invention, the cutting edge of the peripheral cutting edge is provided with a negative chamfer structure, and the chamfer angle of the negative chamfer structure is 3 to 5 degrees.

[0013] According to the embodiments of the present invention, the helix angle of the chip removal groove is 24 to 26 degrees, and the end of the chip removal groove away from the drill tip is provided with an arc structure.

[0014] According to the drill bit of the present invention, the cutting diameter of the cutting part at the peripheral edge is D, and the core diameter of the cutting part at the peripheral edge is 0.26D to 0.28D.

[0015] According to the drill bit of the present invention, the core diameter of the cutting section is gradually reduced along the direction close to the drill tip.

[0016] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments; Figure 1 This is a schematic diagram of the structure of a drill bit according to an embodiment of the present invention; Figure 2 for Figure 1 A schematic diagram of the drill bit from direction A. Figure 3 for Figure 1 A schematic diagram of the end cutting edge of the drill bit shown. Figure 4 This is a force analysis diagram of a drill bit during drilling according to an embodiment of the present invention; Figure 5 A force analysis diagram of an existing drill bit during drilling; Figure 6 for Figure 1 The diagram shows a cross-sectional view of the drill bit at the peripheral cutting edge.

[0018] Figure label: Handle 100; Cutting section 200; drill tip 210; end cutting edge 220; chip groove 230; transverse cutting edge 240; peripheral cutting edge 250; first cylindrical ligament 251; second cylindrical ligament 252; negative chamfer structure 253; chip removal groove 260; arc structure 261. Detailed Implementation

[0019] This section will describe in detail specific embodiments of the present invention. Preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the drawings is to supplement the textual description with graphics, so that people can intuitively and vividly understand each technical feature and overall technical solution of the present invention, but they should not be construed as limiting the scope of protection of the present invention.

[0020] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0021] In the description of this invention, "several" means one or more, "more than" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0022] In the description of this invention, unless otherwise explicitly defined, terms such as "setting," "installing," and "connecting" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0023] The following is for reference. Figures 1 to 6 The drill bit of this application is described in detail.

[0024] refer to Figure 1 and Figure 3According to an embodiment of the present invention, a drill bit includes a shank 100 and a cutting portion 200; one end of the cutting portion 200 is connected to the shank 100, and the other end of the cutting portion 200 forms a drill tip 210. The drill tip 210 has a drill tip angle of 134 degrees to 136 degrees. The drill tip 210 is provided with two end cutting edges 220 that are spaced apart circumferentially along the cutting portion 200. A transverse cutting edge 240 is provided between the two end cutting edges 220. The end cutting edge 220 has a front angle b, a first rear angle c, and a second rear angle d. The front angle b is -11 degrees to -9 degrees, the first rear angle c is 11 degrees to 13 degrees, and the second rear angle d is 21 degrees to 23 degrees. A chip groove 230 is formed between two adjacent end cutting edges 220. The chip groove 230 has a chip groove angle of 39 degrees to 41 degrees.

[0025] It should be noted that when existing drill bits are used to drill into specially shaped surfaces such as inclined planes and curved surfaces, the drill bit is prone to deviation at the moment of contact with the surface due to the poor uniformity of force in all directions. This results in low drilling accuracy on the surface. Therefore, existing drill bits often need to pre-drill holes on the surface before drilling into these surfaces. The drill bit then continues drilling along the pre-drilled holes. This pre-drilling process makes the entire drilling process more complicated.

[0026] It is understood that in the drill bit of this application, since the drill tip angle of the drill tip 210 is 134 to 136 degrees, the rake angle b of the end cutting edge is -11 to -9 degrees, the clearance angle c of the first end cutting edge is 11 to 13 degrees, and the clearance angle d of the second end cutting edge is 21 to 23 degrees, and a chip groove 230 is formed between two adjacent end cutting edges 220, and the chip groove 230 has a chip groove angle of 39 to 41 degrees, during the drilling process of the drill bit of this application, a resultant force is generated towards the drill bit axis at the moment the drill bit contacts the machining surface, thereby realizing automatic correction and adaptive centering of the drill bit. This allows the drill bit of this application to complete the drilling of special shaped machining surfaces such as inclined surfaces and curved surfaces without pre-drilling. At the same time, this design of the drill bit of this application can improve the chip breaking effect, reduce the axial vibration of the drill bit, and thus reduce the probability of chipping of the end cutting edge 220 of the drill bit and the generation of quality defects at the hole opening.

[0027] For example, refer to Figure 4 and Figure 5 Compared to traditional drill bits, the drill bit of this application generates two additional forces, F9 and F11, oriented towards the drill bit axis when machining the surface. This results in a better self-centering effect when drilling special-shaped surfaces such as inclined planes and curved surfaces.

[0028] In some embodiments of the present invention, the drill tip angle is preferably 135 degrees, the end-edge rake angle b is preferably -10 degrees, the end-edge first clearance angle c is preferably 12 degrees, the end-edge second clearance angle d is preferably 22 degrees, and the chip flute angle is preferably 40 degrees.

[0029] In some embodiments of the present invention, reference is made to Figure 2 The bevel angle f of the 240 transverse blade is 114 to 116 degrees.

[0030] It is understandable that by setting the chisel edge angle f of the chisel edge 240 to 114 to 116 degrees, the drill bit of this application can convert the extrusion cutting of the workpiece into shear cutting when drilling the workpiece, thereby reducing the axial feed force of the drill bit during the cutting process and improving the processing efficiency of the drill bit when drilling the workpiece.

[0031] In some embodiments of the present invention, the bevel angle f of the transverse blade 240 is preferably 115 degrees.

[0032] In some embodiments of the present invention, reference is made to Figure 2 The unfolded length L of the transverse blade 240 is 1.1 mm to 1.3 mm.

[0033] Understandably, by setting the unfolded length L of the chisel edge 240 to 1.1 mm to 1.3 mm, the chip groove 230 has a larger chip space. When the drill bit of this application performs drilling on the workpiece, the waste chips can flow into the chip groove 230 more quickly and be discharged along the chip groove 230, thereby reducing the wear of the waste chips on the drill tip 210.

[0034] In some embodiments of the present invention, the unfolded length L of the transverse blade 240 is preferably 1.2 mm.

[0035] In some embodiments of the present invention, reference is made to Figure 2 and Figure 6 The cutting part 200 has two peripheral cutting edges 250 on the corresponding end edge 220. A chip removal groove 260 is formed between two adjacent peripheral cutting edges 250. The chip removal groove 260 corresponds to and is connected to the chip receiving groove 230. The peripheral cutting edge rake angle g of the peripheral cutting edge 250 is 15 degrees to 17 degrees.

[0036] It is understandable that by setting two peripheral cutting edges 250, and setting the peripheral cutting edge rake angle g of the peripheral cutting edge 250 to 15 degrees to 17 degrees, the resistance encountered by the drill bit of this application during drilling can be reduced, thereby improving the drilling efficiency of the drill bit of this application.

[0037] In some embodiments of the present invention, the rake angle g of the peripheral blade 250 is preferably 16 degrees.

[0038] In some embodiments of the present invention, reference is made to Figure 1 and Figure 6 The posterior cutting edge 250 has a first cylindrical ligament 251 and a second cylindrical ligament 252 spaced circumferentially on its posterior cutting surface, and the width of the first cylindrical ligament 251 is different from the width of the second cylindrical ligament 252.

[0039] Understandably, the arrangement of the first cylindrical ligament 251 and the second cylindrical ligament 252, with the widths of the first cylindrical ligament 251 and the second cylindrical ligament 252 being different, allows the first cylindrical ligament 251 and the second cylindrical ligament 252 to abut against the borehole wall during the cutting process within the borehole, thus guiding the drill bit and enabling it to accurately cut along the axial direction of the borehole. The arrangement of the first cylindrical ligament 251 and the second cylindrical ligament 252 effectively resists off-center load on the drill bit, suppresses vibration in the cutting section 200 of the drill bit, and thereby improves the drilling accuracy and the surface finish of the inner wall of the borehole processed by the drill bit.

[0040] Understandably, the arrangement of the first cylindrical ligament 251 and the second cylindrical ligament 252 provides a larger chip space for the large amount of chips generated during the rapid feed process of the drill bit of this application, while reducing the contact area between the drill bit circumference and the borehole wall, thereby reducing the frictional heat and cutting torque generated by the drill bit during operation and improving the stability and wear resistance of the peripheral cutting edge 250 during the machining process.

[0041] In a further embodiment of the present invention, the width of the first cylindrical ligament 251 is 0.29 mm to 0.31 mm, and the width of the second cylindrical ligament 252 is 0.34 mm to 0.36 mm.

[0042] Preferably, the width of the first cylindrical ligament 251 is 0.3 mm, and the width of the second cylindrical ligament 252 is 0.35 mm.

[0043] In some embodiments of the present invention, reference is made to Figure 1 The cutting edge of the circumferential blade 250 is provided with a negative chamfer structure 253, and the chamfer angle of the negative chamfer structure 253 is 3 to 5 degrees.

[0044] It is understandable that by setting a negative chamfer structure 253 on the cutting edge of the peripheral blade 250 and setting the chamfer angle of the negative chamfer structure 253 to 3 to 5 degrees, the impact resistance of the cutting edge of the peripheral blade 250 and the wear resistance of the rake face of the peripheral blade can be improved during the cutting process of the peripheral blade 250, thereby achieving a balance between the sharpness and toughness of the peripheral blade 250.

[0045] In a further embodiment of the present invention, the chamfer angle of the negative chamfer structure 253 is preferably 4 degrees.

[0046] In some embodiments of the present invention, the helix angle of the chip removal groove 260 is 24 to 26 degrees, and the end of the chip removal groove 260 away from the drill tip 210 is provided with an arc structure 261.

[0047] It is understandable that by setting an arc structure 261 at the end of the chip removal groove 260 away from the drill tip 210, the flow resistance of the waste chips during the movement of the chip removal groove 260 can be reduced, thereby improving the smoothness of chip removal from the chip removal groove 260.

[0048] Understandably, by setting the helix angle of the chip removal groove 260 to 24 to 26 degrees, and in conjunction with the arc structure 261 at the end of the chip removal groove 260 away from the drill tip 210, it is possible to achieve directional and controllable smooth discharge of waste chips, reduce the probability of chip blockage in the chip removal groove 260, thereby reducing the instantaneous load on the peripheral cutting edge 250 caused by chip blockage in the chip removal groove 260, which could lead to the risk of the peripheral cutting edge 250 breaking.

[0049] In a further embodiment of the present invention, the helix angle of the chip removal groove 260 is preferably 25 degrees.

[0050] In some embodiments of the present invention, the cutting diameter of the cutting part 200 at the peripheral cutting edge 250 is D, and the core diameter of the cutting part 200 at the peripheral cutting edge 250 is 0.26D to 0.28D.

[0051] Preferably, the core diameter at the cutting part 200 and the peripheral cutting edge 250 is 0.27D.

[0052] In some embodiments of the present invention, the core diameter of the cutting portion 200 is gradually reduced along the direction close to the drill tip 210.

[0053] It is understandable that, along the direction close to the drill tip 210, the core diameter of the cutting part 200 is gradually reduced, thereby increasing the rigidity gradient of the cutting part 200 in the direction away from the drill tip 210. When the drill bit of this application is machining a hole with a large depth or intermittent cutting, it can effectively resist the bending or torque deformation of the cutting part 200, thereby reducing the vibration generated by the cutting part 200.

[0054] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A drill bit, characterized in that, include: Handle (100); The cutting part (200) is connected at one end to the shank (100), and the other end of the cutting part (200) forms a drill tip (210). The drill tip (210) has a drill tip angle of 134 degrees to 136 degrees. The drill tip (210) is provided with two end cutting edges (220) that are spaced apart circumferentially along the cutting part (200). A transverse cutting edge (240) is provided between the two end cutting edges (220). The end cutting edge (220) has a front angle b, a first rear angle c, and a second rear angle d. The front angle b is -11 degrees to -9 degrees, the first rear angle c is 11 degrees to 13 degrees, and the second rear angle d is 21 degrees to 23 degrees. A chip groove (230) is formed between two adjacent end cutting edges (220). The chip groove (230) has a chip groove angle of 39 degrees to 41 degrees.

2. A drill bit according to claim 1, characterized in that, The oblique angle f of the transverse blade (240) is 114 to 116 degrees.

3. A drill bit according to claim 1, characterized in that, The unfolded length L of the transverse blade (240) is 1.1 mm to 1.3 mm.

4. A drill bit according to claim 1, characterized in that, The cutting part (200) has two peripheral cutting edges (250) on its circumference corresponding to the end cutting edge (220). A chip removal groove (260) is formed between two adjacent peripheral cutting edges (250). The chip removal groove (260) corresponds to and is connected to the chip receiving groove (230). The rake angle g of the peripheral cutting edge (250) is 15 degrees to 17 degrees.

5. A drill bit according to claim 4, characterized in that, The circumferential cutting edge (250) has a first cylindrical ligament (251) and a second cylindrical ligament (252) spaced circumferentially on its rear cutting surface, and the width of the first cylindrical ligament (251) is different from the width of the second cylindrical ligament (252).

6. A drill bit according to claim 5, characterized in that, The width of the first cylindrical ligament (251) is 0.29 mm to 0.31 mm, and the width of the second cylindrical ligament (252) is 0.34 mm to 0.36 mm.

7. A drill bit according to claim 4, characterized in that, The cutting edge of the peripheral blade (250) is provided with a negative chamfer structure (253), and the chamfer angle of the negative chamfer structure (253) is 3 to 5 degrees.

8. A drill bit according to claim 4, characterized in that, The helix angle of the chip removal groove (260) is 24 to 26 degrees, and the end of the chip removal groove (260) away from the drill tip (210) is provided with an arc structure (261).

9. A drill bit according to claim 4, characterized in that, The cutting diameter of the cutting part (200) at the peripheral edge (250) is D, and the core diameter of the cutting part (200) at the peripheral edge (250) is 0.26D to 0.28D.

10. A drill bit according to claim 9, characterized in that, The core diameter of the cutting section (200) is gradually reduced along the direction close to the drill tip (210).

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