Drill bit structure for machining 304 stainless steel material
The drill bit structure with a 140° top angle, multiple cutting edges, and chip breaker design addresses the challenges of machining 304 stainless steel by enhancing drilling speed, efficiency, and tool longevity while preventing chip wrapping and improving machining quality.
Patent Information
- Application Number
- CN202510741123.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-04
- Publication Date
- 2025-07-15
AI Technical Summary
When traditional drill bits process 304 stainless steel, chips are difficult to break and wrap, and the heat dissipation performance is insufficient, resulting in low processing efficiency, poor safety and severe tool wear.
A new drill bit structure was designed, including specific top angles, cutting edge counts, spiral grooves and chip breakers, combining high-speed steel material and TiAlN coating to optimize the geometric parameters and heat dissipation performance of the cutting edge.
Improves drilling speed and efficiency, reduces chip wrapping, extends drill bit life, and ensures machining accuracy and safety.
Smart Images
Figure CN120306689A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of stainless steel processing, and particularly relates to a drill bit structure for processing 304 stainless steel materials. Background Art
[0002] As an austenitic stainless steel, 304 stainless steel has excellent corrosion resistance and good mechanical properties, and is widely used in the industrial field. However, due to its material properties, there are many technical problems in the drilling process. When traditional drill bits process 304 stainless steel, due to the characteristics of high material viscosity and poor thermal conductivity, the chips often have difficulty breaking, resulting in the chips winding around the drill bit, seriously affecting the continuity and safety of the processing process. At the same time, the existing drill bit structure has insufficient heat dissipation performance, and is prone to local high temperature during high-speed cutting, accelerating tool wear and even chipping. These problems not only reduce the processing efficiency, but also greatly shorten the tool life and increase the production cost. In addition, the geometric parameter design of conventional drill bits fails to fully consider the material properties of 304 stainless steel, resulting in uneven distribution of cutting forces, further exacerbating the problems of tool wear and unstable processing quality.
[0003] In view of the above-mentioned disadvantages, the present invention proposes a drill bit structure for processing 304 stainless steel materials to solve the above problems. Summary of the Invention
[0004] The present invention provides a drill bit structure for processing 304 stainless steel materials, aiming to solve the problems of difficult heat dissipation, continuous and winding chips around the drill bit, easy wear and chipping of the drill bit, and low efficiency when processing small holes in 304 stainless steel materials.
[0005] The present invention provides a drill bit structure for processing 304 stainless steel materials, and the technical solution adopted is as follows, including: a shank portion, a guiding portion and a cutting portion;
[0006] The cutting portion and the guiding portion include four rake faces, four main cutting edges, four flank faces, two secondary cutting edges, a chisel edge and a helical groove.
[0007] Further, the included angle of the drill bit is 140°, and the length of the cutting portion is 0.7 mm.
[0008] Further, the width of the chisel edge is 0.13 mm.
[0009] Further, the helix angle of the helical groove is 30°, and a chip breaker groove is provided on the helical groove.
[0010] Further, the rake angle distribution of the rake face is: the rake angle at the drill center is -5°, and the rake angle at the outer edge is 10°.
[0011] Furthermore, the distribution of the main cutting edge's principal cutting angle is as follows: the principal cutting angle at the outer edge is 70°, and the principal cutting angle at the drill core is not less than 50°.
[0012] Furthermore, the four main cutting edges include two first main cutting edges and two second main cutting edges. The length of the first main cutting edge is 0.82 mm, and the angle between it and the chisel edge is 22°. The second main cutting edge is arc-shaped, with a length of 1.53 mm and a curvature radius of 1.41 mm. The angle between its tangent and the chisel edge is 65°.
[0013] Furthermore, the longest side of the chip breaker groove is 2.07 mm, the minimum curvature radius is 0.76 mm, and the area is 1.56 mm 2 .
[0014] Furthermore, the four rake faces include two first rake faces and two second rake faces. The minimum curvature radius of the first rake face is 1.8 mm; the four flank faces include two main flank faces and two relief faces.
[0015] Furthermore, the drill bit is made of high-speed steel and its surface is coated with a TiAlN coating.
[0016] Advantages of the present invention:
[0017] 1. The present invention adds two front faces and two main cutting edges, which is equivalent to increasing the number of cutting edges participating in cutting simultaneously. During the drilling process, multiple cutting edges can cut the material simultaneously. Compared with traditional drill bits, more material can be removed in the same time, thus improving the drilling speed and efficiency.
[0018] 2. The rake angle and principal cutting angle of the drill bit change little from the drill core to the outer edge, keeping the cutting edges relatively consistent in sharpness as a whole, which is beneficial for better cutting into the material during the cutting process. At the same time, this design also takes into account the strength of the cutting edges. Because the angle distribution with little change makes the cutting edges bear the cutting force more evenly, reducing local stress concentration, lowering the risk of the cutting edges chipping or wearing, and extending the service life of the drill bit.
[0019] 3. The included angle of the drill bit of the present invention is designed to be 140 degrees. The larger included angle can make the drill bit easier to center when starting to drill, reducing the slip and swing of the drill bit on the workpiece surface, improving the position accuracy of drilling. Especially for the processing of some materials with higher hardness or higher precision requirements, it can effectively avoid drilling position deviation.
[0020] 4. The design of the chip breaker groove in the present invention can make the chips receive a specific curling force during the formation process, thus forming curled chips. These curled chips are not easily wound around the drill bit, ensuring the smooth progress of the cutting process. Description of the Drawings
[0021] For ease of explanation, the present invention will be described in detail by the following specific embodiments and the accompanying drawings.
[0022] Figure 1 is a schematic structural view of the present invention;
[0023] Figure 2 is a schematic structural view of the present invention;
[0024] Figure 3 is of the present invention Figure 2 magnified view A;
[0025] Figure 4 is a top view of the present invention.
[0026] In the figure: 1, shank portion; 2, guiding portion; 3, cutting portion; 4, major flank; 5, minor flank; 6, spiral groove; 7, minor cutting edge; 8, chisel edge; 9, chip breaker groove; 10, first rake face; 11, second rake face; 12, first major cutting edge; 13, second major cutting edge.
[0027] Wherein, Figure 4 α is the vertex angle. Specific Embodiments
[0028] The following are specific embodiments of the present invention in combination with the accompanying drawings to further describe the technical solutions of the present invention, but the present invention is not limited to these embodiments; in the following description, specific details such as specific configurations and components are provided only to help a comprehensive understanding of the embodiments of the present invention. Therefore, those skilled in the art should clearly understand that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of the present invention. In addition, descriptions of known functions and structures are omitted for clarity and conciseness.
[0029] It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other.
[0030] Such as Figures 1 to 4 shown in a specific embodiment of a drill bit structure for machining 304 stainless steel material, including: a shank portion 1, a guiding portion 2, and a cutting portion 3; the cutting portion 3 and the guiding portion 2 include four rake faces, four major cutting edges, four flank faces, two minor cutting edges 7, one chisel edge 8, and a spiral groove 6.
[0031] Specifically, the shank part 1 refers to the clamping area connected to the machine tool spindle, which can be specifically implemented with a cylindrical or conical structure to provide a stable torque transmission basis for the cutting process. The guiding part 2 refers to the cylindrical area near the cutting end, which can be specifically implemented with a diameter size matching the hole diameter to continuously correct the movement trajectory of the drill bit during the drilling process. The cutting part 3 refers to the edge area that performs the material removal function, and the cutting force distribution is balanced by increasing the number of effective cutting edges.
[0032] Specifically, compared with the headstock drill bit, the present invention adds two rake faces and two main cutting edges, which is equivalent to increasing the number of cutting edges participating in cutting simultaneously. During the drilling process, multiple cutting edges can cut the material simultaneously, and compared with traditional drill bits, more material can be removed in the same time, thereby improving the drilling speed and efficiency.
[0033] In other preferred embodiments, the tip angle α of the drill bit is 140°, the length of the cutting part 3 is 0.7 mm. The width of the chisel edge 8 is 0.13 mm, the helix angle of the helical flute 6 is 30°, and a chip breaker groove 9 is provided on the helical flute 6.
[0034] Specifically, setting the tip angle α to 140° makes the main cutting edge form a gentler inclination angle, which reduces the frictional contact with the hole wall when the chip is discharged outward along the helical flute 6 during the cutting process, thereby reducing the heat accumulation in the cutting area. When the length of the cutting part 3 is set to 0.7 mm, while ensuring the effective cutting depth, the continuous contact path between the cutting edge and the workpiece is shortened, so that the heat generated during the cutting process can be quickly dissipated through the chip breaking action and the cooling medium. The synergistic effect of these two parameters reconstructs the geometric shape of the cutting area, which not only optimizes the chip breaking frequency, but also improves the heat dissipation conditions by reducing the friction contact time between the cutting edge and the material.
[0035] Specifically, the tip angle α is set to 140°. The larger tip angle α can make the axial force distribution during cutting more reasonable, reducing the axial pressure on the workpiece during drilling. This is very beneficial for processing some thin materials or easily deformable materials, and can prevent the workpiece from deforming or being damaged due to excessive axial force.
[0036] Specifically, the present invention limits the width of the chisel edge 8 to 0.13 mm. When the chisel edge 8 is at this width, the chisel edge 8 at this size can not only bear the axial cutting force, but also will not excessively squeeze the workpiece material, thereby reducing the accumulation of cutting heat. During continuous processing, this structure promotes the stable discharge of chips along the helical flute 6, avoiding secondary friction caused by chip accumulation.
[0037] Specifically, when the helix angle is controlled at 30°, it not only maintains a sufficient chip discharge channel cross-sectional area to smoothly discharge the chips, but also avoids the reduction of the drill body rigidity caused by an excessive angle. The chip breaker groove 9 and the spiral groove 6 form a continuous surface. When the chips move along the spiral groove 6, the edge of the chip breaker groove 9 exerts a local bending effect on the chips, causing the chips to break at a predetermined position. This combined structure forces the long strip-shaped chips to be broken during the discharge process, eliminating the problem of chip entanglement around the drill body. At the same time, the directional chip discharge function of the spiral groove 6 accelerates the air flow in the cutting area and promotes heat dissipation.
[0038] Specifically, the design of the chip breaker groove 9 enables the chips to be subjected to a specific curling force during formation, thereby forming curled debris. This curled debris is not easily entangled around the drill bit, ensuring the smooth progress of the cutting process. The curled debris has a regular shape, which is conducive to discharging from the drilled hole. During the drilling process, a good chip discharge effect can prevent chips from accumulating in the hole, reducing the scratching of the machined surface by the chips and the interference with the subsequent cutting process, improving the surface quality and machining efficiency of the drilling. Since the chips can be discharged in time and will not accumulate and be repeatedly cut in the drilling area, the generation and accumulation of cutting heat are reduced. A lower cutting temperature helps to reduce the wear rate of the drill bit, improve the durability of the drill bit, and is also conducive to ensuring the machining accuracy and surface quality of the workpiece, avoiding changes in the material properties of the workpiece or thermal deformation caused by high temperature.
[0039] In other preferred embodiments, the present invention further proposes that the rake angle distribution of the front tool face is set such that the rake angle at the drill center is -5° and the rake angle at the outer edge is 10°. The main cutting edge has a main cutting edge angle distribution as follows: the main cutting edge angle at the outer edge is 70°, and the main cutting edge angle at the drill center is not less than 50°.
[0040] Specifically, the rake angle of -5° at the drill center forms a wedge-shaped support structure at the cutting edge, which resists the transverse shear force by increasing the material compression area when machining high-viscosity materials and reduces the direct thermal shock of the cutting temperature on the cutting edge. The rake angle of 10° at the outer edge shortens the contact length between the chips and the front tool face, achieving a chip breaking effect by reducing the chip curling radius. The continuous change of the rake angle from the drill center to the outer edge makes the cutting force distribution gradient, achieving chip shape control while maintaining the integrity of the cutting edge.
[0041] Specifically, the main cutting edge angle at the outer edge of the drill bit is about 70°. As it approaches the drill center, the main cutting edge angle gradually decreases, and another main cutting edge angle is added at the drill center, so that the main cutting edge angle is not less than 50°. The cutting force changes little from the drill center to the outer edge.
[0042] Specifically, the rake angle and the main cutting edge angle of the drill bit change little from the drill core to the outer edge, keeping the cutting edge relatively consistent in sharpness as a whole, which is conducive to better cutting into the material during the cutting process. At the same time, this design also takes into account the strength of the cutting edge. Because of the small-angle distribution, the cutting edge bears the cutting force more evenly, reducing local stress concentration, lowering the risk of the cutting edge chipping or wearing, and extending the service life of the drill bit.
[0043] In other preferred embodiments, the four main cutting edges include two first main cutting edges 12 and two second main cutting edges 13. The length of the first main cutting edge 12 is 0.82 mm, and the angle between it and the transverse edge 8 is 22°. The second main cutting edge 13 is arc-shaped, with a length of 1.53 mm and a curvature radius of 1.41 mm. The angle between its tangent and the transverse edge 8 is 65°. The four rake faces include two first rake faces 10 and two second rake faces 11. The minimum curvature radius of the first rake face 10 is 1.8 mm. The four flank faces include two main flank faces 4 and two secondary flank faces 5.
[0044] Specifically, at least a section between the first main cutting edge 12 and the second main cutting edge 13 is arc-shaped. In the present invention, the second main cutting edge 13 is arc-shaped. The arc shape is likely to produce curly chips, which is conducive to tool cutting and extends the service life of the tool.
[0045] Specifically, during the rotary cutting process of the drill bit, the first main cutting edge 12 bears the main impact load by virtue of its compact structure, and efficiently removes the material through the cutting-in method with a 22° included angle, while avoiding the edge chipping caused by stress concentration. The second main cutting edge 13 forms a progressive cutting trajectory by using its arc-shaped contour. The 65° tangent angle promotes the orderly discharge of chips along the spiral groove. The continuous cutting effect generated by the control of the curvature radius can reduce heat accumulation. The two main cutting edges form a complementary layout in space. The first main cutting edge 12 ensures the cutting stability of the drill core part, and the second main cutting edge 13 optimizes the chip removal efficiency of the outer edge area, jointly realizing the dynamic balance of cutting force and heat during the machining process.
[0046] Specifically, by dividing the rake face into two different structural types, the first rake face 10 with a smaller curvature radius is adopted in the drill core area to enhance the structural strength, while the second rake face 11 with different curvature characteristics is configured in the outer edge area to improve the heat dissipation conditions. The transition area between the first rake face 10 and the second rake face 11 is connected by a continuous curved surface, enabling the heat generated during the cutting process to be dispersed and conducted along different curvature surfaces. When the tool contacts the workpiece, the specific curvature radius of the first rake face 10 can avoid stress concentration caused by sharp corners, while the extended contour of the second rake face 11 provides an extended discharge channel for the chips.
[0047] In other preferred embodiments, the longest side of the chip breaker groove 9 is 2.07 mm, the minimum radius of curvature is 0.76 mm, and the area is 1.56 mm 2 .
[0048] Specifically, the longest side of the chip breaker groove 9 being 2.07 mm forms a space sufficient to accommodate the chips, avoiding secondary shearing caused by chip accumulation. The minimum radius of curvature of 0.76 mm is the critical value for balancing stress distribution and chip bending deformation, causing the chips to bend at a predetermined angle during the flow process. The area of the chip breaker groove 9 being 1.56 mm 2 is defined to both maintain the structural strength of the drill body and ensure the timely detachment of the chips from the machining area. The combined control of these three geometric parameters causes the chips to break periodically during the flow process, while increasing the heat dissipation contact area through the groove structure.
[0049] In other preferred embodiments, the drill bit material is high-speed steel, and the surface is coated with a TiAlN coating.
[0050] Specifically, when machining 304 stainless steel, the high-speed steel substrate maintains the edge shape stability through the solution strengthening effect, avoiding edge deformation caused by material softening; the TiAlN coating blocks the heat conduction path through the nano-layered structure, reducing the substrate temperature gradient, and at the same time, the alumina film formed on its surface reduces the coating wear caused by iron element diffusion.
[0051] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they specify the presence of features, steps, operations, devices, components, and / or combinations thereof.
[0052] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation of the present invention.
[0053] In addition, the terms "first", "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first", "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise specifically defined.
[0054] Those skilled in the art to which the present invention pertains can make various modifications, supplements, or use similar means of substitution to the described specific embodiments, but will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.
Claims
1. A drill bit structure for machining 304 stainless steel material, characterized in that, It includes a shank part, a guiding part and a cutting part; The cutting part and the guiding part include four rake faces, four major cutting edges, four flank faces, two minor cutting edges, one chisel edge and spiral grooves.
2. The drill bit structure for processing 304 stainless steel material according to claim 1, characterized in that, The drill bit has a point angle of 140°, and the length of the cutting part is 0.7 mm.
3. The drill bit structure for processing 304 stainless steel material according to claim 1, characterized in that, The width of the chisel edge is 0.13 mm.
4. A drill bit structure for processing 304 stainless steel material according to claim 1, characterized in that The spiral angle of the spiral groove is 30°, and chip-breaking grooves are provided on the spiral groove.
5. The drill bit structure for processing 304 stainless steel material according to claim 1, wherein, The rake angle distribution of the rake face is as follows: the rake angle at the drill center is -5°, and the rake angle at the outer edge is 10°.
6. The drill bit structure for processing 304 stainless steel material according to claim 1, wherein, The principal cutting-edge angle distribution of the major cutting edge is as follows: the principal cutting-edge angle at the outer edge is 70°, and the principal cutting-edge angle at the drill center is not less than 50°.
7. The drill bit structure for processing 304 stainless steel material according to claim 1, wherein, The four major cutting edges include two first major cutting edges and two second major cutting edges. The length of the first major cutting edge is 0.82 mm, and the angle between it and the chisel edge is 22°. The second major cutting edge is arc-shaped, with a length of 1.53 mm and a curvature radius of 1.41 mm. The angle between its tangent and the chisel edge is 65°.
8. The drill bit structure for processing 304 stainless steel material according to claim 4, wherein, The longest side of the chip breaker groove is 2.07 mm, the minimum radius of curvature is 0.76 mm, and the area is 1.56 mm 2 .
9. The drill bit structure for processing 304 stainless steel material according to claim 1, characterized in that, The four rake faces include two first rake faces and two second rake faces. The minimum curvature radius of the first rake face is 1.8 mm; the four flank faces include two major flank faces and two minor flank faces.
10. The drill bit structure for processing 304 stainless steel material according to claim 1, characterized in that, The drill bit is made of high-speed steel, and the surface is coated with a TiAlN coating.