A non-standard milling cutter for machining complex curved surfaces

Abstract

The utility model provides a nonstandard milling cutter for complex curved surface processing, including handle and blade part, and the front end of blade part is equipped with the cutter tip, is equipped with four main cutting edges of radial extension on the cutter tip, and four main cutting edges are asymmetric structure, is equipped with the helical chip flute on the circumference of blade part, the lead and spiral angle of helical chip flute middle region all gradually become big from the end close to the drill tip to the handle end, and the lead and spiral angle of helical chip flute both ends close to cutter tip and handle region all keep constant, is equipped with the fish scale type groove on the groove surface of helical chip flute and forms fish scale type chip flute, and is equipped with the oval transition curved surface on the cutter tip. This milling cutter asymmetric blade edge makes cutting force fluctuation reduce, and eliminates processing vibration mark, and variable lead groove cooperates fish scale type chip flute, and solves titanium alloy long chip jamming problem, and oval cutter tip reduces curved surface tool mark, and improves precision, and cutter tip reinforced platform reduces the rate of broken edge, and improves tool life.

Description

Technical Field

[0001] This utility model relates to the field of cutting tool technology, and in particular to a non-standard milling cutter for machining complex curved surfaces, mainly used in the fields of aerospace engine blade machining and precision curved surface machining of artificial joints. Background Technology

[0002] When machining surfaces with small curvature, traditional ball end mills cause periodic fluctuations in cutting force due to the symmetrical cutting edge, leading to tool chatter and surface texture. At the same time, the equal lead chip flutes can easily cause long chips to clog the tool body, resulting in tool breakage.

[0003] In view of this, it is necessary to improve the existing milling cutters to solve the above problems. Utility Model Content

[0004] The technical problem to be solved by this utility model is: in order to overcome the shortcomings of the prior art, this utility model provides a non-standard milling cutter for machining complex curved surfaces, which is used to efficiently mill complex free curved surfaces of titanium alloys and high-temperature alloys, eliminate machining vibration and improve surface accuracy.

[0005] The technical solution adopted by this utility model to solve its technical problem is as follows: a non-standard milling cutter for machining complex curved surfaces, including a shank and a cutting edge. The cutting edge has a cutting tip at its front end, and four radially extending main cutting edges are provided on the cutting tip. The central angles between the four main cutting edges are γ1, γ2, γ1, and γ2, respectively, and γ1 and γ2 are not equal, so that the main cutting edges form an asymmetrical structure. A spiral chip removal groove is provided on the circumferential surface of the cutting edge. The lead and helix angle of the middle region of the spiral chip removal groove gradually increase from the end near the drill tip to the end of the shank. The lead and helix angle of the two ends of the spiral chip removal groove near the cutting tip and the shank are kept constant. Centrifugal force is used to accelerate chip discharge. The small helix angle of the cutting tip maintains cutting stability, and the increased helix angle in the middle section can improve chip removal. The surface of the spiral chip removal groove is provided with fish-scale grooves to form a fish-scale chip removal groove, and the cutting tip is provided with an elliptical transition surface.

[0006] Preferably, the central angle γ1 of the main cutting edge is 93°, and the central angle γ2 of the main cutting edge is 87°. Through the unequal division design of 93° / 87°, the tool can maintain a stable cutting state under machining conditions, reducing vibration.

[0007] Furthermore, to protect the cutting tip, a cutting tip protection platform is provided at the tip of the main cutting edge. The dimensions of the cutting tip protection platform are 0.2mm × 45°. The cutting tip protection platform strengthens the cutting tip and prevents chipping.

[0008] Preferably, the lead of the spiral chip removal groove gradually increases from 30 mm to 45 mm.

[0009] Preferably, the helix angle α of the helical chip removal groove near the tip is 22°, and the helix angle β near the shank is 32°.

[0010] Furthermore, the spiral chip removal groove adopts a gradient design, with the groove depth extending from 0.3mm in the tip area to 0.8mm in the shank area to avoid chip retention.

[0011] Furthermore, the chip removal grooves distributed along the axis of the cutter body are designed as fish-scale grooves, arranged in a fan shape, with slightly raised edges. The width of the fish-scale grooves is 0.2-0.5mm and the depth is 0.1-0.2mm.

[0012] Furthermore, the major axis radius R1 of the elliptical transition surface is 1.5 mm, and the minor axis radius R2 is 0.8 mm. The tool tip adopts an elliptical transition surface, which adapts to the tool tip geometry and matches the contour of a workpiece with small curvature.

[0013] Furthermore, the back face of the main cutting edge is provided with a fish tail fin structure to improve the surface finish and reduce vibration.

[0014] Specifically, the fish tail fin structure includes several fin rays, which are distributed in parallel with an angle θ of 60° based on the main cutting edge. The height of the fin rays is 15-30 μm and the spacing is 50-80 μm.

[0015] The beneficial effects of this utility model are: (1) Vibration suppression: The asymmetric cutting edge reduces the fluctuation of cutting force and eliminates machining vibration marks; (2) Chip removal efficiency: The variable lead groove combined with the fish scale chip removal groove solves the problem of long chips clogging in titanium alloys; (3) Improved precision: The elliptical tool tip reduces tool marks on curved surfaces; (4) Extended lifespan: The tool tip strengthening platform reduces the chipping rate and improves tool lifespan. Attached Figure Description

[0016] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0017] Figure 1 This is a side view of the non-standard milling cutter used for machining complex curved surfaces according to this utility model.

[0018] Figure 2 This is a side view of the non-standard milling cutter used for machining complex curved surfaces according to this utility model.

[0019] Figure 3 yes Figure 2 A magnified structural diagram of point I in the middle.

[0020] Figure 4This is a schematic diagram of the top structure of the non-standard milling cutter used for machining complex curved surfaces according to this utility model.

[0021] Figure 5 This is a schematic diagram of the top structure of the non-standard milling cutter used for machining complex curved surfaces according to this utility model.

[0022] Figure 6 yes Figure 5 A magnified structural diagram of point A in the middle.

[0023] Figure 7 yes Figure 5 A magnified structural diagram at point B in the middle.

[0024] In the diagram: 1. Shank, 2. Shank neck, 3. Cutting edge, 4. Main cutting edge, 5. Spiral chip removal groove, 6. Fish scale groove, 7. Tip protection platform, 8. Elliptical transition surface, 9. Fish tail fin structure, 10. Back face. Detailed Implementation

[0025] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0026] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model 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, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0027] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances. Furthermore, the technical features involved in the different embodiments of this utility model described below can be combined with each other as long as they do not conflict with each other.

[0028] like Figure 1 and Figure 2 As shown, this utility model discloses a non-standard end mill for machining complex curved surfaces, including a shank 1 and a cutting edge 3. A shank neck 2 is provided between the shank 1 and the cutting edge 3 to achieve a transition connection between the shank 1 and the cutting edge 3. A helical chip removal groove 5 is provided on the circumferential surface of the cutting edge 3. Through the combination structure of the asymmetric main cutting edge 4 and the variable lead helical groove, the cutting force is dynamically balanced and chip removal is forced, thus solving the vibration and chip clogging problems in high-speed machining.

[0029] like Figure 1 and Figure 4 As shown, the cutting edge 3 has a tip at its front end, and four radially extending main cutting edges 4 are provided on the tip. The central angles between the four main cutting edges are γ1, γ2, γ1, and γ2, respectively, and γ1 and γ2 are not equal, forming an asymmetrical structure for the main cutting edges. Preferably, the central angle γ1 of the main cutting edges is 93°, and the central angle γ2 of the main cutting edges is 87°. Through the 93° / 87° unequal division design, the tool can maintain a stable cutting state under machining conditions and reduce vibration.

[0030] like Figure 2 As shown, the lead and helix angle of the central region of the spiral chip removal groove 5 gradually increase from the end near the drill tip to the end of the shank 1. The lead and helix angle of the spiral chip removal groove 5 at both ends near the drill tip and the shank 1 remain constant. Centrifugal force is used to accelerate chip removal. The small helix angle at the drill tip maintains cutting stability, while the increased helix angle in the middle section improves chip removal. Preferably, the lead of the spiral chip removal groove 5 gradually increases from P1 to P2. In this embodiment, P1 = 30 mm and P2 = 45 mm. The helix angle α of the spiral chip removal groove 5 near the drill tip is 22°, and the helix angle β near the shank 1 is 32°. The groove depth of the spiral chip removal groove 5 adopts a gradual design, extending from 0.3 mm in the drill tip area to 0.8 mm in the shank 1, to avoid chip retention. In this embodiment, the total length L1 of the milling cutter is 80mm, the length L2 of the shank 1 is 25mm, the length L3 of the cutting edge 3 is 45mm, the shank diameter φ1 is 6.0mm, and the cutting edge diameter φ2 is 5.0mm.

[0031] like Figure 2 and Figure 3 As shown, the spiral chip removal groove 5 has fish-scale grooves 6 on its groove surface to form a fish-scale chip removal groove. The chip removal grooves are distributed along the axis of the tool body and designed as fish-scale grooves 6, arranged in a fan shape with slightly raised edges. The width of the fish-scale grooves 6 is 0.2-0.5mm and the depth is 0.1-0.2mm.

[0032] like Figure 5 and Figure 6As shown, to protect the cutting edge, a cutting edge protection platform 7 is provided at the tip of the main cutting edge 4. The dimensions of the cutting edge protection platform 7 are 0.2mm × 45°. The cutting edge protection platform 7 strengthens the cutting edge and prevents chipping. An elliptical transition surface 8 is also provided on the cutting edge. The major axis radius R1 of the elliptical transition surface 8 is 1.5mm, and the minor axis radius R2 is 0.8mm. The cutting edge uses an elliptical transition surface 8, which adapts to the cutting edge geometry and matches the contour of a workpiece with small curvature.

[0033] like Figure 5 and Figure 7 As shown, a fishtail fin structure 9 is provided on the rear face 10 of the main cutting edge 4 to improve the surface finish and reduce vibration. The fishtail fin structure 9 includes a plurality of fin rays, which are distributed in parallel with an inclination angle θ of 60° relative to the main cutting edge. The height of the fin rays is 15-30 μm and the spacing is 50-80 μm. In this embodiment, there are four fin rays on each side of the rear face.

[0034] Based on the above-described preferred embodiments of this utility model, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the scope of this utility model. The technical scope of this utility model is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A non-indexable milling cutter for machining complex curved surfaces, characterized by: The tool includes a shank and a cutting edge. The cutting edge has a tip at its front end, and four radially extending main cutting edges are provided on the tip. The central angles between the four main cutting edges are γ1, γ2, γ1, and γ2, respectively, and γ1 and γ2 are not equal, forming an asymmetrical structure of the main cutting edges. The circumferential surface of the cutting edge has a spiral chip removal groove. The lead and helix angle of the central region of the spiral chip removal groove gradually increase from the end near the drill tip to the end of the shank. The lead and helix angle of the two ends of the spiral chip removal groove near the drill tip and the shank remain constant. The surface of the spiral chip removal groove has fish-scale grooves to form a fish-scale chip removal groove. The cutting edge has an elliptical transition surface.

2. The non-standard end mill for machining complex curved surfaces as described in claim 1, characterized in that: The central angle γ1 of the main cutting edge is 93°, and the central angle γ2 of the main cutting edge is 87°.

3. The non-standard end mill for machining complex curved surfaces as described in claim 1, characterized in that: The tip of the main cutting edge is provided with a tip protection platform, the dimensions of which are 0.2mm × 45°.

4. The non-standard end mill for machining complex curved surfaces as described in claim 1, characterized in that: The lead of the spiral chip removal groove gradually increases from 30 mm to 45 mm.

5. The non-standard end mill for machining complex curved surfaces as described in claim 4, characterized in that: The helix angle α of the helical chip removal groove near the tip is 22°, and the helix angle β near the shank is 32°.

6. The non-standard end mill for machining complex curved surfaces as described in claim 1, characterized in that: The spiral chip removal groove has a gradually changing depth, extending from 0.3mm at the tip to 0.8mm at the shank.

7. The non-standard end mill for machining complex curved surfaces as described in claim 1, characterized in that: The width of the fish-scale groove is 0.2-0.5 mm and the depth is 0.1-0.2 mm.

8. The non-standard end mill for machining complex curved surfaces as described in claim 1, characterized in that: The major axis radius R1 of the elliptical transition surface is 1.5 mm, and the minor axis radius R2 is 0.8 mm.

9. The non-standard end mill for machining complex curved surfaces as described in claim 1, characterized in that: The back face of the main cutting edge is provided with a fish tail fin structure.

10. The non-standard end mill for machining complex curved surfaces as described in claim 9, characterized in that: The fish tail fin structure includes several fin rays, which are distributed in parallel with an angle θ of 60° based on the main cutting edge. The height of the fin rays is 15-30μm and the spacing is 50-80μm.

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