A concave-edge milling tool suitable for ultrasonic vibration-assisted machining

Abstract

This invention discloses a concave-edge milling cutter suitable for ultrasonic vibration-assisted machining, comprising a clamping part and a cutting part connected to one end of the clamping part. The end face of the cutting part has multiple radially arranged end cutting edges, and the side face of the cutting part has multiple axially extending and spaced side cutting edges. The intersection of the side cutting edges and the end cutting edges forms a cutting tip. At least one of the side cutting edges and the end cutting edges has at least one concave cutting edge section near the cutting tip. The concave cutting edge includes a first cutting edge and a second cutting edge. The first cutting edge is positioned closer to the cutting tip than the second cutting edge, and the cutting angle of the first cutting edge is greater than that of the second cutting edge. The cutting angle is either an axial rake angle or a radial rake angle. This invention, through the arrangement of the concave cutting edges, eliminates the need for alternating side cutting edges (or end cutting edges) with different helix angles, which is beneficial for increasing the number of cutting edges and improving cutting variations.

Description

Technical Field

[0001] This invention relates primarily to the field of metal cutting, and more particularly to a concave-edge milling tool suitable for ultrasonic vibration-assisted machining. Background Technology

[0002] In milling, the number and shape of the cutting edge affect milling efficiency and stability. Currently, the cutting part of milling tools is made of relatively expensive cemented carbide or superhard materials. Due to the high hardness and good wear resistance of these materials, they are extremely difficult to process. Generally, the cutting edge of these materials can only be prepared by grinding and other processing methods. Due to the limitations of grinding and other processes, milling tools can only use straight or helical cutting edges.

[0003] Currently, high-temperature alloys are widely used in aerospace engine materials. With the increasing speed of aerospace vehicles, the thrust-to-weight ratio requirement for engines has reached over 11, with inlet temperatures as high as 1900K. The temperature resistance limit of high-temperature alloys, only 1350K, is insufficient to meet the material requirements of high thrust-to-weight ratio engines. Ceramic matrix composites, with a temperature resistance exceeding 2300K, are gradually becoming ideal materials for engines. However, ceramic matrix composites are anisotropic and heterogeneous, and possess high hardness and brittleness. During machining, defects such as fiber debonding, material delamination, fiber burrs, and chipping / tearing at hole entrances and exits are easily encountered. Ordinary milling tools are insufficient to meet the manufacturing precision and efficiency requirements.

[0004] To address the aforementioned technical problems, milling cutters are designed with alternating cutting edges of different helix angles to improve manufacturing accuracy. However, because these alternating cutting edges with different helix angles require a large amount of space, such milling cutters have a small number of cutting edges and exhibit significant variations in cutting conditions, resulting in short tool life and low efficiency. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a concave-edge milling tool with high machining accuracy suitable for ultrasonic vibration-assisted machining.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0007] A concave-edge milling cutter includes a clamping part and a cutting part connected to one end of the clamping part. The end face of the cutting part is provided with a plurality of radially arranged end cutting edges, and the side face of the cutting part is provided with a plurality of side cutting edges extending in the axial direction and spaced apart. The intersection of the side cutting edges and the end cutting edges is the cutting tip. At least one of the side cutting edges and the end cutting edges is provided with at least one concave cutting edge in the direction near the cutting tip. The concave cutting edge includes a first cutting edge and a second cutting edge. The first cutting edge is arranged in the direction closer to the cutting tip than the second cutting edge. The cutting angle of the first cutting edge is greater than the cutting angle of the second cutting edge. The cutting angle is an axial rake angle or a radial rake angle.

[0008] As a further improvement to the above technical solution:

[0009] The end cutting edge is provided with a concave cutting edge. The first cutting edge is denoted as the first peripheral cutting edge, and the second cutting edge is denoted as the first core cutting edge. The radial rake angle of the first peripheral cutting edge is greater than that of the first core cutting edge.

[0010] On any plane perpendicular to the central axis of the milling tool, the angle between the projection lines of the first peripheral cutting edge and the first core cutting edge of the same concave cutting edge is α. The radial rake angles of the first peripheral cutting edge and the first core cutting edge of the same concave cutting edge are α1 and α1', respectively, which should satisfy: 130°≤α≤150°, 5°≤α1≤25°, -20°≤α1'≤5°.

[0011] The side cutting edge is provided with a concave cutting edge. The first cutting edge is denoted as the first bottom cutting edge, and the second cutting edge is denoted as the first top cutting edge. The axial rake angle of the first bottom cutting edge is greater than the axial rake angle of the first top cutting edge.

[0012] On the plane passing through the central axis of the milling tool, the axial angle between the projection lines of the first bottom cutting edge and the first top cutting edge on the same side is β. The axial rake angles of the first bottom cutting edge and the first top cutting edge on the same side are β1 and β1', respectively, which should satisfy: 130°≤β≤150°, 30°≤β1≤50°, -30°≤β1'≤10°.

[0013] The end cutting edge has M concave cutting edges, and the side cutting edge has N concave cutting edges, which should satisfy: 1≤M≤3, 2≤N≤5.

[0014] The cutting part has multiple end cutting teeth on its end face and multiple side cutting teeth on its side surface. The end cutting edge is located on the end cutting tooth and the side cutting edge is located on the side cutting tooth. The number of end cutting teeth is denoted as X and the number of side cutting teeth is denoted as Y. The following conditions must be met: 10≤X, Y≤30.

[0015] The maximum groove width of the adjacent end cutting teeth in the direction near the outer circumference of the end face is Wmax, and the minimum groove width in the direction near the central axis is W. min It should satisfy: 0.3mm≤W max -W min ≤ 1mm, 2≤W max / W min ≤4.

[0016] The side cutting edge and the end cutting edge are connected to each other and are arranged accordingly.

[0017] The milling cutter has a cooling channel that is connected to the outside. The cooling channel includes a main cooling channel and at least two secondary cooling channels. The two ends of the secondary cooling channel are respectively provided with a core cooling port and a peripheral cooling port. The secondary cooling channel is connected to the main cooling channel through the core cooling port. The groove between adjacent side cutting teeth is a side cutting groove. The peripheral cooling port of the secondary cooling channel is located on the side cutting groove.

[0018] The core cooling inlets of different auxiliary cooling channels are set on different normal surfaces, and the normal surface is a surface perpendicular to the central axis.

[0019] The number of normal surfaces along the central axis is τ, the axial distance between adjacent normal surfaces is d, and the cutting tool diameter is D. The following conditions must be met: 2≤τ≤4, 0.2D≤d≤0.4D.

[0020] The cooling channel also includes an end cooling channel arranged along the central axis. The end cooling channel is connected to the main cooling channel. The cross-sectional area of ​​the main cooling channel is S1, and the cross-sectional area of ​​the end cooling channel is S2. The condition should be: 0.3S1≤S2≤0.5S1.

[0021] Each of the adjacent side cutting edges has an independent secondary cooling channel corresponding to its side groove. The cross-sectional area of ​​the core cooling inlet of the secondary cooling channel is S3, which should satisfy: 2S3≤ ≤3S3.

[0022] The cross-sectional area of ​​the peripheral cooling inlet is S3', which should satisfy: 0.2S3≤S3'≤0.5S3.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0024] This invention discloses a concave-edge milling cutter with cutting edges on both the end face and the side face. At least one of the side cutting edges and the end cutting edge has at least one concave cutting edge section near the cutting tip. The concave cutting edge includes a first cutting edge and a second cutting edge. The first cutting edge is positioned closer to the cutting tip than the second cutting edge. The cutting angle of the first cutting edge is greater than that of the second cutting edge. The cutting angle is either an axial rake angle or a radial rake angle. By using the concave cutting edge, this invention eliminates the need to alternately set side cutting edges (or end cutting edges) with different helix angles, which is beneficial for increasing the number of cutting edges and improving cutting differences. By using the different cutting angles of the first and second cutting edges, this invention can reduce axial and radial cutting forces, improve manufacturing surface accuracy, and reduce vibration, avoiding surface damage and delamination. The fact that the cutting angle of the first cutting edge is greater than that of the second cutting edge can reduce the cutting impact when cutting into the workpiece, solving problems such as material delamination, fiber burrs, and chipping and tearing at the hole entrance and exit in the processing of ceramic matrix and other composite materials, thereby improving tool life and cutting efficiency. Attached Figure Description

[0025] Figure 1 This is a perspective view of the first embodiment of the concave-edge milling cutter of the present invention applicable to ultrasonic vibration-assisted machining.

[0026] Figure 2 yes Figure 1 A magnified view of a section at point C.

[0027] Figure 3 This is a front view of the first embodiment of the concave-edge milling cutter of the present invention, applicable to ultrasonic vibration-assisted machining.

[0028] Figure 4 yes Figure 3 Sectional view along line AA.

[0029] Figure 5 This is a left view of the first embodiment of the concave-edge milling cutter of the present invention applicable to ultrasonic vibration-assisted machining.

[0030] Figure 6 yes Figure 3 Sectional view along the BB line.

[0031] Figure 7 This is a perspective view of a second embodiment of the concave-edge milling cutter of the present invention applicable to ultrasonic vibration-assisted machining.

[0032] Figure 8 yes Figure 7 A magnified view of a section at point E in the middle.

[0033] Figure 9 This is a front view of the second embodiment of the concave-edge milling cutter of the present invention, applicable to ultrasonic vibration-assisted machining.

[0034] Figure 10 This is a left view of the second embodiment of the concave-edge milling cutter of the present invention applicable to ultrasonic vibration-assisted machining.

[0035] Figure 11 This is a perspective view of the third embodiment of the concave-edge milling cutter of the present invention applicable to ultrasonic vibration-assisted machining.

[0036] Figure 12 yes Figure 11 A magnified view of a section at point F.

[0037] Figure 13 This is a front view of the third embodiment of the concave-edge milling cutter of the present invention applicable to ultrasonic vibration-assisted machining.

[0038] The labels in the diagram represent:

[0039] 1. Clamping part; 2. Cutting part; 21. End cutting tooth; 211. End rake face; 212. End flank face; 213. End cutting edge; 214. End concave cutting edge; 214a. First peripheral cutting edge; 214b. First core cutting edge; 214c. First end arc cutting edge; 22. Side cutting tooth; 221. Side rake face; 222. Side flank face; 223. Side cutting edge; 224. Side concave cutting edge; 224a. First bottom cutting edge; 224b. First top cutting edge; 224c. First side arc cutting edge; 225. Side groove; 3. Central shaft; 31. Normal surface; 4. Cooling channel; 41. Main cooling channel; 42. Secondary cooling channel; 421. Core cooling port; 422. Peripheral cooling port; 43. End cooling channel. Detailed Implementation

[0040] The present invention will be further described in detail below. Unless otherwise specified, the instruments or materials used in the present invention are commercially available.

[0041] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship 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 limitations on this invention.

[0042] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0043] In this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," "fixed," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0044] like Figure 1 and Figure 2 As shown, in this embodiment, a clamping part 1 and a cutting part 2 connected to one end of the clamping part 1 are included. The end face of the cutting part 2 is provided with a plurality of radially arranged end cutting edges 213. The side face of the cutting part 2 is provided with a plurality of side cutting edges 223 extending in the axial direction and spaced apart. The intersection of the side cutting edges 223 and the end cutting edges 213 is the tip of the cutting edge. At least one of the side cutting edges 223 and the end cutting edges 213 is provided with at least one concave cutting edge in the direction near the tip of the cutting edge. The concave cutting edge includes a first cutting edge and a second cutting edge. The first cutting edge is arranged in the direction closer to the tip of the cutting edge than the second cutting edge. The cutting angle of the first cutting edge is greater than the cutting angle of the second cutting edge. The cutting angle is an axial rake angle or a radial rake angle. This invention, through the setting of a concave cutting edge, eliminates the need for alternating side cutting edges (or end cutting edges) with different helical angles, which is beneficial for increasing the number of cutting edges and improving cutting differences. By using the different cutting angles of the first and second cutting edges, this invention can reduce axial and radial cutting forces, improve manufacturing surface accuracy, reduce vibration, and avoid surface damage and delamination. The cutting angle of the first cutting edge being greater than that of the second cutting edge can reduce the cutting impact when cutting into the workpiece, solving problems such as material delamination, fiber burrs, and edge chipping and tearing at the hole entrance and exit in the processing of ceramic matrix and other composite materials, thereby improving tool life and cutting efficiency.

[0045] Example 1

[0046] The present invention is applicable to ultrasonic vibration-assisted machining of concave cutting edge milling tools, including three forms of radial, axial and combined vibration, corresponding to end milling, side milling and combined milling, respectively, and solves the surface quality, cutting force and vibration problems corresponding to radial, axial and radial-axial combination.

[0047] Figures 1 to 6This invention discloses a first embodiment of a concave-edge milling cutter suitable for ultrasonic vibration-assisted machining. The milling cutter includes a clamping part 1 and a cutting part 2 connected to one end of the clamping part 1. The clamping part 1 is symmetrical about a central axis 3. The end face and side face of the cutting part 2 are respectively provided with a plurality of end cutting teeth 21 and a plurality of side cutting teeth 22. The end cutting teeth 21 are composed of an end rake face 211, an end flank face 212 and an end cutting edge 213 located between the end rake face 211 and the end flank face 212. The side cutting teeth 22 are composed of a side rake face 221, a side flank face 222 and a side cutting edge 223 located between the side rake face 221 and the side flank face 222. The end cutting edge 213 is provided with at least one end concave cutting edge 214, wherein the end concave cutting edge 214 adjacent to the side is composed of a first peripheral cutting edge 214a, a first core cutting edge 214b and a first end arc cutting edge 214c located between the first peripheral cutting edge 214a and the first core cutting edge 214b. Figure 2 For the same concave cutting edge, the starting point P1 on the first peripheral cutting edge 214a in the direction away from the first core cutting edge 214b, the starting point P2 in the direction close to the first core cutting edge 214b, the starting point P3 on the first core cutting edge 214b in the direction close to the first peripheral cutting edge 214a, and the starting point P4 in the direction away from the first peripheral cutting edge 214a, segment P1P2 is the first peripheral cutting edge 214a, segment P2P3 is the first end arc cutting edge 214c, and segment P3P4 is the first core cutting edge 214b. The side cutting edge 223 is provided with at least one side concave cutting edge 224, wherein the side concave cutting edge 224 adjacent to the end face is composed of a first bottom cutting edge 224a, a first top cutting edge 224b, and a first side arc cutting edge 224c located between the first bottom cutting edge 224a and the first top cutting edge 224b. Figure 2 For the same concave cutting edge, the starting point Q1 on the first bottom cutting edge 224a in the direction away from the first top cutting edge 224b, the starting point Q2 in the direction closer to the first top cutting edge 224b, the starting point Q3 on the first top cutting edge 224b in the direction closer to the first bottom cutting edge 224a, and the starting point Q4 in the direction away from the first bottom cutting edge 224a, the segment Q1Q2 is the first bottom cutting edge 224a, the segment Q2Q3 is the first top cutting edge 224b, and the segment Q3Q4 is the first side arc cutting edge 224c.

[0048] To reduce the cutting force of the end cutting tooth 21 at small cutting widths and improve its cutting stability at large cutting widths (due to the effect of the concave cutting edge at large cutting widths), a radial force distribution is proposed within the end face to address surface quality issues. The radial cutting angle α1 of the first cutting edge 214a is greater than the radial cutting angle α1' of the first core cutting edge 214b. Figure 5As shown, in this embodiment, the radial cutting angle refers to the radial rake angle. On a plane perpendicular to the central axis 3 of the milling tool, for the same concave cutting edge, the projection point of the starting point P1 on the first cutting edge 214a away from the first core cutting edge 214b is denoted as P1', and the projection point of the starting point P2 on the first cutting edge 214a near the first core cutting edge 214b is denoted as P2'. The projection point O of the central axis 3 is used as the first radial reference line, with the line connecting the projection point P1' and the projection point O. The angle between the projection line of the cutting edge 214a and the first radial reference line is α1. The projection point of the starting point P3 on the first core cutting edge 214b, which is closer to the first circumferential cutting edge 214a, is denoted as P3'. The projection point of the starting point P4 on the first core cutting edge 214b, which is farther away from the first circumferential cutting edge 214a, is denoted as P4'. The line connecting the projection point P3' and the projection point O of the central axis 3 is taken as the second radial reference line. The angle between the projection line of the first core cutting edge 214b and the second radial reference line is α1'.

[0049] On any plane perpendicular to the central axis 3 of the milling tool, the included angle between the projection lines of the first peripheral cutting edge 214a and the first core cutting edge 214b of the same concave cutting edge is α. To reduce the cutting force when cutting a small width and ensure the edge strength, thereby promoting the stability of radial cutting and the surface quality during ultrasonic vibration-assisted machining, the following conditions should be met: 130°≤α≤150°, 5°≤α1≤25°, -20°≤α1'≤5°. In this embodiment, α=140°, α1=15°, α1'=-18°.

[0050] In this embodiment, the first cutting edge 214a and the first core cutting edge 214b are straight cutting edges.

[0051] To reduce the cutting force of the side cutting teeth 22 at small depths of cut and improve cutting stability at the depth of cut, and to address the issues of side perpendicularity and axial force distribution caused by side milling, the axial cutting angle β1 of the first bottom cutting edge 224a is greater than the axial cutting angle β1' of the first top cutting edge 224b, such as... Figure 3 As shown.

[0052] On the plane passing through the central axis 3 of the milling tool, the axial angle between the projection lines of the first bottom cutting edge 224a and the first top cutting edge 224b on the same side of the cutting edge 223 is β. The axial cutting angles of the first bottom cutting edge 224a and the first top cutting edge 224b are β1 and β1', respectively. To ensure the stability of axial cutting and the surface quality during ultrasonic vibration assisted machining, the following conditions should be met: 30°≤β1≤50°, -30°≤β1'≤10°. In this embodiment, β1=120°, β1=40°, β1'=-20°. In this embodiment, the axial cutting angle refers to the axial rake angle. On the plane passing through the central axis 3 of the milling tool, the projection line of the first bottom cutting edge 224a (… Figure 3 The angle between the projection line of segment Q1'Q2' and the projection line of the central axis 3 is β1, and the projection line of the first top cutting edge 224b ( Figure 3 The angle between the projection line of the middle Q3'Q4' segment and the central axis 3 is β1'.

[0053] In this embodiment, the first bottom cutting edge 224a and the first top cutting edge 224b are straight cutting edges.

[0054] The end cutting edge 213 has M concave cutting edges 214, and the side cutting edge 223 has at least N concave cutting edges 224. To reduce radial force, axial force, and tool cutting vibration during ultrasonic vibration-assisted machining, the following conditions should be met: 1≤M≤3, 2≤N≤5. In this embodiment, M =1, N =2. In this embodiment, the number of concave cutting edges 214 on each end cutting edge 213 is the same, and the number of concave cutting edges 224 on each side cutting edge 223 is the same. In other embodiments, the number of concave cutting edges 214 on each end cutting edge 213 and the number of concave cutting edges 224 on each side cutting edge 223 may be different.

[0055] In this invention, the end cutting edge 213 or the side cutting edge 223 has at least one concave cutting edge. When the end cutting edge 213 has two or more concave cutting edges, the cutting force distribution from the core to the radial surface of the end cutting edge 213 is greatly optimized. When the side cutting edge 223 has two or more concave cutting edges, the axial force distribution from the bottom (near the end face) to the tail (away from the end face) of the side cutting edge 223 is optimized, effectively reducing the radial and axial cutting vibration and deformation of the tool and improving the surface quality of the machined part.

[0056] In this embodiment, the clamping part 1 and the cutting part 2 are made of cemented carbide, and the cutting part 2 is welded to the tool clamping part 1.

[0057] The cutting part 2 has X end cutting teeth 21 and Y side cutting teeth 22 on its end face and side face, respectively. The end cutting edge 213 is located on the end cutting tooth 21, and the side cutting edge 223 is located on the side cutting tooth 22. To ensure cutting efficiency, cutting stability, and surface quality during ultrasonic vibration assisted machining, the following conditions should be met: 10≤X, Y≤30. In this embodiment, X=Y=18. Compared with the prior art, the number of end cutting teeth 21 and side cutting teeth 22 in this invention is greatly increased. The side cutting edges 223 on each side cutting tooth 22 of this invention are arranged in parallel. Compared with existing milling tools with different helix angle cutting edges, this invention can set more side cutting edges 223 in a limited space. Similarly, the end cutting edges 213 on each end cutting tooth 21 of this invention are arranged radially. The size and direction of the concave cutting edge of adjacent end cutting edges 213 are consistent. There is no interference between the end cutting edges 213 due to different helix angles, which facilitates increasing the number of end cutting edges 213.

[0058] In this invention, the adjacent side cutting edge 223 and the end cutting edge 213 are connected to each other and are arranged accordingly.

[0059] like Figure 5 As shown, the end cutting teeth 21 are arranged radially, and chip grooves are provided between adjacent end cutting teeth 21. The groove width of adjacent end cutting teeth 21 is smaller in the direction near the central axis 3 and larger in the direction near the outer circumference of the end face. Let the maximum groove width of adjacent end cutting teeth 21 in the direction near the outer circumference of the end face be W. max The minimum slot width on the side closest to the central axis 3 is W. min To improve the cooling effect in the chip groove between adjacent cutting teeth 21 and to increase the edge strength and chip removal efficiency at different cutting speeds, and to solve the technical problems of poor tool body cooling and unreasonable chip space, the following requirement should be met: 0.3mm ≤ W max -W min ≤1mm, 2≤W max / W min ≤4. In this embodiment, W min =0.3mm, W max =0.9mm.

[0060] When the end face of the cutting part 2 is a plane, the milling tool can perform plane milling and step milling.

[0061] The milling cutter has a cooling channel 4 at its center that communicates with the outside. The cooling channel 4 includes a main cooling channel 41 and at least two secondary cooling channels 42. The two ends of the secondary cooling channels 42 are respectively provided with a core cooling port 421 and a peripheral cooling port 422. The secondary cooling channels 42 communicate with the main cooling channel 41 through the core cooling port 421. The groove between adjacent side cutting teeth 22 is a side groove 225 (e.g., Figure 6As shown), the peripheral cooling inlets 422 of the secondary cooling channel 42 are located on the side groove 225 corresponding to the side cutting edge 223. The core cooling inlets 421 of different secondary cooling channels 42 are set on different normal surfaces 31. The normal surface 31 is a surface perpendicular to the central axis (and passes through the center of the core cooling inlet 421). Similarly, the peripheral cooling inlets 422 of different secondary cooling channels 42 are set on different normal surfaces 31 (and pass through the center of the peripheral cooling inlet 422). The peripheral cooling inlets 42 are set near the middle of the side cutting tooth 22.

[0062] like Figure 3 and Figure 4 As shown, adjacent core cooling ports 421 have τ normal surfaces 31 along the central axis 3, with an axial distance d between adjacent normal surfaces 31. The cutting tool diameter of the cutting part 2 is D, which should satisfy: 2≤τ≤4, 0.2D≤d≤0.4D. By designing the number τ of normal surfaces 31 and the distance d between adjacent normal surfaces, the secondary cooling channel 42 is discretized. This significantly improves tool life and machining accuracy by enhancing tool heat dissipation and tool strength. In this embodiment, τ=2, d=0.3D. The present invention accurately designs the number of normal surfaces 31 and the distance between adjacent normal surfaces 31, greatly improving tool life and machining accuracy. By setting cooling holes on different normal surfaces 31, the present invention can improve the strength of the tool neck (the neck refers to the part where the cutting part 2 and the clamping part 1 are connected).

[0063] The cooling channel 4 includes an end cooling channel 43 arranged along the central axis 3. The end cooling channel 43 is connected to the main cooling channel 41. The cross-sectional area of ​​the main cooling channel 41 is S1, and the cross-sectional area of ​​the end cooling channel 43 is S2. To improve the cooling pressure of the concave cutting edge 214 at the upper end of the end cutting tooth 21, the following condition should be met: 0.3S1≤S2≤0.5S1. In this embodiment, S2=0.4S1. The present invention accurately designs the cross-sectional areas of the main cooling channel 41 and the end cooling channel 43, precisely adjusts the cooling flow of the end face and the side face, and improves the performance of the end cutting edge 213 and the side cutting edge 223.

[0064] Each cutting edge 223 on each side has an independent secondary cooling channel 42. The cross-sectional area of ​​the core cooling port 421 of the secondary cooling channel 42 is S3. In order for the main cooling channel 41 to provide a large cooling pressure and cooling flow to the core cooling port 421, the following condition should be met: 2S3≤ ≤3S3. In this embodiment, S3 = 0.03S1. The cross-sectional area of ​​the peripheral cooling port 422 is S3'. To ensure that the core cooling port 421 provides a large cooling pressure and cooling flow rate to the peripheral cooling port 422, the following condition should be met: 0.2S3 ≤ S3' ≤ 0.5S3. In this embodiment, S3' = 0.4S1.

[0065] The present invention accurately designs the cross-sections of the core cooling port 421 and the peripheral cooling port 422, which greatly increases the cooling pressure in the side groove 225 corresponding to each side cutting edge 223, effectively improving the cutting efficiency and life of the side cutting edge 223.

[0066] Example 2

[0067] Figures 7 to 10 This invention discloses a second embodiment of a concave-edge milling cutter suitable for ultrasonic vibration-assisted machining. The only difference between this embodiment and Embodiment 1 is that:

[0068] 1. The clamping part 1 is made of cemented carbide, and the cutting part 2 is made of diamond. The cutting part 2 is welded to the tool clamping part 1.

[0069] 2. The side cutting edge 223 has a concave cutting edge, while the end cutting edge 213 does not have a concave cutting edge and is a straight cutting edge. The cutting part 2 has a top end near the clamping part 1 and a bottom end away from the clamping part 1. The peripheral cooling port 422 is provided near the top of the side cutting tooth 22 (near the neck).

[0070] Other similarities will not be repeated here.

[0071] Example 3

[0072] Figures 11 to 13 This invention discloses a third embodiment of a concave-edge milling tool, the only difference between this embodiment and the first embodiment being:

[0073] 1. Side cutting edge 223 is not a concave cutting edge, but a spiral cutting edge.

[0074] In this embodiment, the side cutting edge 223 is a spiral cutting edge. In order to simplify the process and reduce manufacturing costs, in other embodiments, the side cutting edge 223 can also be designed as a straight cutting edge.

[0075] Other similarities will not be repeated here.

[0076] In the above embodiments, the end cutting edge 213 of the milling tool is set on a plane, and the milling tool can realize plane milling and step milling applications. The present invention is not limited to this. Depending on the different cutting application conditions, the end cutting edge 213 of the milling tool can also be set on a spherical surface, and the milling tool can realize contour milling and other milling operations.

[0077] The milling cutter disclosed in this invention exhibits superior technical effects when applied to ultrasonic vibration-assisted machining, such as better surface finish and higher efficiency. Furthermore, this invention can also resolve issues such as material delamination, fiber burrs, and edge chipping / tearing at hole entrances and exits when applied to non-ultrasonic vibration-assisted machining. Whether or not the milling cutter disclosed in this invention employs ultrasonic vibration-assisted machining, it should fall within the scope of protection of this invention.

[0078] While the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the invention. Any person skilled in the art can make many possible variations and modifications to the technical solutions of the present invention, or modify them into equivalent embodiments, without departing from the scope of the present invention. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention, without departing from the scope of the present invention, should fall within the protection scope of the present invention.

Claims

1. A concave blade type milling tool suitable for ultrasonic vibration assisted machining, comprising a clamping part (1) and a cutting part (2) connected to one end of the clamping part (1), an end surface of the cutting part (2) is provided with a plurality of radially arranged end cutting edges (213), and a side surface of the cutting part (2) is provided with a plurality of axially extending and spaced side cutting edges (223), the intersection of the side cutting edge (223) and the end cutting edge (213) is a blade tip, characterized in that: At least one of the side cutting edge (223) and the end cutting edge (213) has at least one concave cutting edge in the direction near the tip of the cutting edge. The concave cutting edge includes a first cutting edge and a second cutting edge. The first cutting edge is positioned closer to the tip of the cutting edge than the second cutting edge. The cutting angle of the first cutting edge is greater than the cutting angle of the second cutting edge. The cutting angle is either an axial rake angle or a radial rake angle.

2. The concave-edge milling tool suitable for ultrasonic vibration-assisted machining according to claim 1, characterized in that, The end cutting edge (213) is provided with a concave cutting edge. The first cutting edge is denoted as the first peripheral cutting edge (214a), and the second cutting edge is denoted as the first core cutting edge (214b). The radial rake angle of the first peripheral cutting edge (214a) is greater than that of the first core cutting edge (214b).

3. The concave-edge milling tool suitable for ultrasonic vibration-assisted machining according to claim 2, characterized in that: On any plane perpendicular to the central axis (3) of the milling tool, the included angle between the projection line of the first peripheral cutting edge (214a) and the projection line of the first core cutting edge (214b) of the same concave cutting edge is α. The radial rake angles of the first peripheral cutting edge (214a) and the first core cutting edge (214b) of the same concave cutting edge are α1 and α1' respectively, which should satisfy: 130°≤α≤150°, 5°≤α1≤25, -20°≤α1'≤5°.

4. The concave-edge milling cutter suitable for ultrasonic vibration-assisted machining according to claim 1, characterized in that: The side cutting edge (223) is provided with a concave cutting edge. The first cutting edge is denoted as the first bottom cutting edge (224a), and the second cutting edge is denoted as the first top cutting edge (224b). The axial rake angle of the first bottom cutting edge (224a) is greater than the axial rake angle of the first top cutting edge (224b).

5. The concave-edge milling cutter suitable for ultrasonic vibration-assisted machining according to claim 4, characterized in that: On the plane passing through the central axis (3) of the milling tool, the axial angle between the projection lines of the first bottom cutting edge (224a) and the first top cutting edge (224b) of the same side cutting edge (223) is β. The axial rake angles of the first bottom cutting edge (224a) and the first top cutting edge (224b) of the same side cutting edge (223) are β1 and β1' respectively, which should satisfy: 130°≤β≤150°, 30°≤β1≤50°, -30°≤β1'≤10°.

6. The concave-edge milling cutter suitable for ultrasonic vibration-assisted machining according to any one of claims 1 to 5, characterized in that: The end cutting edge (213) has M concave cutting edges, and the side cutting edge (223) has N concave cutting edges, which should satisfy: 1≤M≤3, 2≤N≤5.

7. The concave-edge milling tool suitable for ultrasonic vibration-assisted machining according to claim 6, characterized in that: The cutting part (2) has multiple end cutting teeth (21) on its end face and multiple side cutting teeth (22) on its side surface. The end cutting edge (213) is located on the end cutting tooth (21) and the side cutting edge (223) is located on the side cutting tooth (22). The number of end cutting teeth (21) is denoted as X and the number of side cutting teeth (22) is denoted as Y. The following conditions must be met: 10≤X, Y≤30.

8. The concave-edge milling cutter suitable for ultrasonic vibration-assisted machining according to claim 7, characterized in that: The maximum groove width of the adjacent end cutting teeth (21) in the direction close to the outer circumference of the end surface is W max The minimum groove width in the direction close to the center axis (3) is W min The following should be satisfied: 0.3mm ≤ W max - W min ≤ 1mm, 2 ≤ W max / W min ≤ 4.

9. The concave-edge milling cutter suitable for ultrasonic vibration-assisted machining according to claim 7, characterized in that: The side cutting edge (223) and the end cutting edge (213) are connected to each other and are arranged accordingly.

10. The concave-edge milling cutter suitable for ultrasonic vibration-assisted machining according to claim 9, characterized in that: The milling cutter has a cooling channel (4) that is connected to the outside. The cooling channel (4) includes a main cooling channel (41) and at least two secondary cooling channels (42). The two ends of the secondary cooling channel (42) are respectively provided with a core cooling port (421) and a peripheral cooling port (422). The secondary cooling channel (42) is connected to the main cooling channel (41) through the core cooling port (421). The groove between adjacent side cutting teeth (22) is a side cutting groove (225). The peripheral cooling port (422) of the secondary cooling channel (42) is located on the side cutting groove (225). The core cooling port (421) of different auxiliary cooling channels (42) is set on different normal surfaces (31), which are surfaces perpendicular to the central axis (3).

11. The concave-edge milling tool suitable for ultrasonic vibration-assisted machining according to claim 10, characterized in that: The number of normal surfaces (31) along the central axis (3) is τ, the axial distance between adjacent normal surfaces (31) is d, and the diameter of the cutting part (2) is D. It should satisfy: 2≤τ≤4, 0.2D≤d≤0.4D.

12. The concave-edge milling tool suitable for ultrasonic vibration-assisted machining according to claim 10, characterized in that: The cooling channel (4) also includes an end cooling channel (43) arranged along the central axis (3). The end cooling channel (43) is connected to the main cooling channel (41). The cross-sectional area of ​​the main cooling channel (41) is S1, and the cross-sectional area of ​​the end cooling channel (43) is S2. The following conditions should be met: 0.3S1≤S2≤0.5S1.

13. The concave-edge milling tool suitable for ultrasonic vibration-assisted machining according to claim 12, characterized in that: Each of the adjacent side cutting edges (223) has an independent secondary cooling channel (42) corresponding to the side groove (225). The cross-sectional area of ​​the core cooling port (421) of the secondary cooling channel (42) is S3, which should satisfy: 2S3≤ ≤3S3.

14. The concave-edge milling tool suitable for ultrasonic vibration-assisted machining according to claim 13, characterized in that: The cross-sectional area of ​​the peripheral cooling port (422) is S3', which should satisfy: 0.2S3≤S3'≤0.5S3.

15. The concave-edge milling cutter suitable for ultrasonic vibration-assisted machining according to claim 1, characterized in that: The end face of the cutting part (2) is a plane, and the milling tool can realize plane milling and step milling.

16. The concave-edge milling cutter suitable for ultrasonic vibration-assisted machining according to claim 1, characterized in that: The end face of the cutting part (2) is spherical, and the milling tool can perform contour milling.

17. The concave-edge milling tool suitable for ultrasonic vibration-assisted machining according to claim 1, characterized in that: The clamping part (1) is made of cemented carbide, and the cutting part (2) is made of diamond or cemented carbide. The cutting part (2) is welded to the clamping part (1).

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