A cutting insert for drilling

Abstract

The application discloses a cutting blade for drilling, which comprises a polygonal plate-shaped blade body surrounded by an upper surface, a lower surface and a plurality of side surfaces connecting the upper surface and the lower surface. Each of the side surfaces comprises a main side surface, a finishing surface and a transition surface arranged in sequence. The main side surface intersects with the upper surface to form a main cutting unit. The transition surface intersects with the upper surface to form a circular arc transition edge. The finishing surface intersects with the upper surface to form a finishing edge. In the direction of the side surface of the cutting blade, the finishing surface is in the shape of an arched surface. The curvature radius of the finishing surface at the finishing edge is R1. The drilling radius of a drilling tool provided with the cutting blade is R. The following condition should be met: R-2mm<=R1<=R. The application has the advantages of small cutting vibration, high machining precision and the like.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of metal cutting, in particular to a cutting blade for drilling. BACKGROUND

[0002] In order to meet the precision requirements of machining parts in precision machinery manufacturing, a polishing plane can be ground on the drilling blade to improve the drilling precision in drilling processing. However, due to the long overhanging cutting of the drilling tool system, the low rigidity easily causes tool vibration, and the stability cannot be maintained during drilling. The drilling resistance accelerates the wear of the polishing edge, the blade is easily broken, and the service life of the tool is reduced. SUMMARY

[0003] The technical problem to be solved by the present application is to overcome the shortcomings of the prior art and provide a cutting blade for drilling with small cutting vibration, high machining precision and long service life.

[0004] To solve the above technical problems, the present application adopts the following technical scheme:

[0005] A cutting blade for drilling, comprising a polygonal plate-shaped blade body, the blade body is surrounded by an upper surface, a lower surface and a plurality of side surfaces connecting the upper surface and the lower surface, each of the side surfaces comprises a main side surface, a polishing surface and a transition surface arranged in sequence, the main side surface intersects with the upper surface to form a main cutting unit, the transition surface intersects with the upper surface to form a circular arc transition edge, and the polishing surface intersects with the upper surface to form a polishing edge. In the direction of the side surface of the cutting blade, the polishing surface is in the shape of an arched surface, the curvature radius of the polishing surface at the polishing edge is R1, and the drilling radius of the drilling tool provided with the cutting blade is R, which should satisfy: R-2mm≤R1≤R.

[0006] As a further improvement of the above technical scheme:

[0007] The polishing surface is formed by a plurality of segmental circular arc surfaces tangent from top to bottom, and the circular arc radius Rn of each segmental circular arc surface should satisfy: R1-3mm≤Rn≤R1.

[0008] The included angle between the polishing edge and the rotation center line of the drilling tool provided with the cutting blade is a, which should satisfy: 0°≤a≤1°.

[0009] The length of the polishing edge is L, and the diameter of the inscribed circle of the plurality of main cutting units is d, which should satisfy: 10% d≤L≤15% d.

[0010] The polishing surface is located entirely within the drilling hole cylindrical surface of the drilling tool provided with the cutting blade, and the maximum gap distance between the polishing surface and the drilling hole cylindrical surface is L1, which should satisfy: 0

[0011] The tangent direction of the light finishing surface at the light finishing edge forms an angle θ with the upper surface, and the following condition should be satisfied: 85°≤θ≤90°.

[0012] The main cutting unit comprises two straight cutting edges with the same length, and the angle between the two straight cutting edges is β, and the following condition should be satisfied: 150°≤β≤180°.

[0013] Compared with the prior art, the present application has the following advantages:

[0014] The cutting blade for drilling of the present application forms a light finishing edge by the intersection of the light finishing surface and the upper surface, and the light finishing surface is in the shape of an arc in the direction of the side surface of the cutting blade. In the case of unstable drilling, the light finishing surface composed of several arc surfaces can assist in supporting the drilling, and the light finishing surface has several regions that can participate in the drilling, thereby dispersing the drilling resistance of the light finishing edge, ensuring that the surface precision, the stability of the drilling and the consistency of the hole diameter can be well met even in the case of unstable drilling. The curvature radius of the light finishing surface at the light finishing edge is R1, the drilling radius of the drilling tool provided with the cutting blade is R, and the following condition should be satisfied: R-2mm≤R1≤R. The curvature radius R1 of the light finishing surface at the light finishing edge is close to the drilling radius R and is located in the range of R-2mm≤R1≤R, which can meet the requirements of light finishing precision and ensure that the light finishing edge will not easily collapse in the case of unstable drilling, thereby improving the service life of the blade. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 is the perspective view of the first embodiment of the cutting blade for drilling of the present application.

[0016] Figure 2 is the front view of the first embodiment of the cutting blade for drilling of the present application.

[0017] Figure 3 is the schematic view of the cutting blade for drilling of the first embodiment of the present application participating in the drilling process.

[0018] Figure 4 is the perspective view of the second embodiment of the cutting blade for drilling of the present application.

[0019] Figure 5 is the front view of the second embodiment of the cutting blade for drilling of the present application.

[0020] Figure 6 is the schematic view of the cutting blade for drilling of the second embodiment of the present application participating in the drilling process.

[0021] Figure 7 is Figure 6 is the enlarged view of A in FIG.

[0022] The various reference signs in the drawings represent:

[0023] 1. blade body; 2. upper surface; 3. lower surface; 4. side surface; 41. main side surface; 42. finishing surface; 43. transition surface; 5. main cutting unit; 51. main cutting edge; 6. arc transition edge; 7. finishing edge; 8. rotation center line; 9. drilling hole cylindrical surface. DETAILED DESCRIPTION

[0024] The application will be further described below in conjunction with the drawings and specific examples.

[0025] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "horizontal", "inner", "outer", "top", "bottom", and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0026] Figures 1 to 3 A first embodiment of the cutting blade for drilling of the present application is shown, which includes a polygonal plate-shaped blade body 1 surrounded by an upper surface 2, a lower surface 3, and a plurality of side surfaces 4 connecting the upper surface 2 and the lower surface 3, each side surface 4 including a main side surface 41, a finishing surface 42, and a transition surface 43 arranged in sequence, the main side surface 41 intersecting the upper surface 2 to form a main cutting unit 5, the transition surface 43 intersecting the upper surface 2 to form an arc transition edge 6, and the finishing surface 42 intersecting the upper surface 2 to form a finishing edge 7. In the side surface direction of the cutting blade, the finishing surface 42 is in the shape of a cambered surface, and during drilling, several regions on the finishing surface 42 can participate in drilling in the case of unstable drilling, reducing the drilling resistance of the finishing edge 7, i.e., ensuring that the surface precision can be well processed even in the case of unstable drilling, and ensuring the stability and guidance of drilling. The radius of curvature of the finishing surface 42 at the finishing edge 7 is R1, and the drilling radius of the drilling tool provided with the cutting blade is R, which should satisfy: R-2mm≤R1≤R, i.e., the finishing precision requirement is met, and the finishing edge 7 will not easily collapse in the case of unstable drilling, improving the service life of the blade. In this embodiment, R=20mm and R1=19mm.

[0027] In this embodiment, the finishing surface 42 is a circular arc surface with a radius Rn, which reduces the processing difficulty, and the circular arc radius Rn should satisfy: R1-3mm≤Rn≤R1. In this embodiment, Rn=19mm.

[0028] In the embodiment, the included angle between the light trimming edge 7 and the rotation center line 8 of the drill bit provided with the cutting blade is α, and 0°≤α≤1° should be met, which can ensure that the light trimming edge 7 and the drilling surface are in contact at an angle of 0-1° during drilling, thereby ensuring the surface finish of the drilling surface. In the embodiment, α=0.5°.

[0029] In the embodiment, the length of the light trimming edge 7 is L, and the diameter of the inscribed circle of the plurality of main cutting units 5 is d, and 10% d≤L≤15% d should be met, so as to ensure that the light trimming edge 7 participates in light trimming during drilling. In the embodiment, the diameter of the inscribed circle d=10 mm, and L=1.05 mm.

[0030] In the embodiment, the light finishing surface 42 is entirely located in the drilling hole cylindrical surface 9 of the drill bit provided with the cutting blade, and the maximum gap distance between the light finishing surface 42 and the drilling hole cylindrical surface 9 is L1, and 0<L1≤0.1 mm should be met, which can ensure that the light finishing surface with several arc surfaces can participate in drilling in the case of unstable drilling, and reduce the drilling resistance of the light trimming edge 7. In the embodiment, L1=0.05 mm.

[0031] In the embodiment, the tangent direction of the light finishing surface 42 at the light trimming edge 7 forms an included angle θ with the upper surface 2, and 85°≤θ≤90° should be met, which can ensure that the light trimming edge 7 participates in drilling in preference to other positions of the light finishing surface during drilling. In the embodiment, θ=89°.

[0032] In the embodiment, the main cutting unit 5 includes two straight cutting edges 51 with the same length, and the included angle between the two straight cutting edges 51 is β, and 150°≤β≤180° should be met. In the embodiment, β=160°.

[0033] Figures 4 to 7 A second embodiment of the cutting blade for drilling of the application is shown. The cutting blade for drilling of the embodiment is basically the same as the first embodiment, and the difference is that, in the embodiment, the light finishing surface 42 is formed by three arc surfaces tangent from top to bottom, and each arc radius Rn meets R1-3 mm≤Rn≤R1. In the embodiment, R1=20 mm, R2=18 mm, and R3=15 mm. In the embodiment, β=180°, that is, the two straight cutting edges 51 form a straight cutting edge.

[0034] Although the present application has been disclosed with reference to the preferred embodiments, it is not intended to limit the present application. Any person skilled in the art, without departing from the technical scope of the present application, can make many possible changes and modifications to the disclosed technical content of the present application, or modify equivalent embodiments of equivalent changes. Therefore, any simple modification, equivalent change and modification made to the above embodiments without departing from the technical content of the present application, according to the technical essence of the present application, shall fall within the scope of protection of the present application.

Claims

1. A cutting insert for drilling, comprising a polygonal plate-shaped insert body (1) which is enclosed by an upper surface (2), a lower surface (3) and a plurality of side surfaces (4) connecting the upper surface (2) and the lower surface (3), characterized in that: Each of the side surfaces (4) comprises a main side surface (41), a finishing surface (42) and a transition surface (43) arranged in sequence, the main side surface (41) intersects with the upper surface (2) to form a main cutting unit (5), the transition surface (43) intersects with the upper surface (2) to form a circular arc transition edge (6), the finishing surface (42) intersects with the upper surface (2) to form a finishing edge (7), in the side surface direction of the cutting insert, the finishing surface (42) is in the shape of an arc surface, the curvature radius of the finishing surface (42) at the finishing edge (7) is R1, the drilling radius of the drilling tool provided with the cutting insert is R, and the following condition should be met: R-2mm≤R1≤R.

2. The cutting insert for drilling according to claim 1, characterized in that: The finishing surface (42) is formed by a plurality of arc surfaces tangent from top to bottom, and the arc radius Rn of each arc surface should meet the following condition: R1-3mm≤Rn≤R1.

3. The cutting insert for drilling according to claim 1, characterized in that: The angle between the finishing edge (7) and the rotation center line (8) of the drilling tool provided with the cutting insert is α, and the following condition should be met: 0°≤α≤1°.

4. The cutting insert for drilling according to claim 1, characterized in that: The length of the finishing edge (7) is L, the diameter of the inscribed circle of the plurality of main cutting units (5) is d, and the following condition should be met: 10%d≤L≤15%d.

5. The cutting insert for drilling according to any one of claims 1 to 3, characterized in that: The finishing surface (42) is located inside the drilling hole cylindrical surface (9) of the drilling tool provided with the cutting insert as a whole, and the maximum gap distance between the finishing surface (42) and the drilling hole cylindrical surface (9) is L1, and the following condition should be met: 0<L1≤0.1mm.

6. The cutting insert for drilling according to any one of claims 1 to 3, characterized in that: The tangent direction of the finishing surface (42) at the finishing edge (7) forms an angle θ with the upper surface (2), and the following condition should be met: 85°≤θ≤90°.

7. The cutting insert for drilling according to any one of claims 1 to 3, characterized in that: The main cutting unit (5) comprises two straight cutting edges (51) with the same length, and the angle between the two straight cutting edges (51) is β, and the following condition should be met: 150°≤β≤180°.

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