A new type of end mill

Abstract

This invention discloses a novel end mill, comprising a shank and a cutting section. The cutting section is connected to the shank and extends along the axial direction of the shank. The cutting section includes at least one cutter body and at least one discharge groove. The cutter body and the discharge groove are arranged adjacent to each other and spirally arranged along the axis of the cutting section. A milling edge is provided at the end of the cutter body away from the shank. The cutting section is made of a composite material, which includes an ultrahard part and a rigid part. The connection between the ultrahard part and the rigid part forms a boundary surface. The boundary surface coincides with or forms an angle with the axis of the cutting section. The part covered by the ultrahard part includes the milling edge, while the part covered by the rigid part does not include the milling edge. By concentrating the ultrahard part at the milling edge and the rigid part at the non-milling edge, the novel end mill possesses an ultrahard cutting edge and a highly rigid shank, thereby enabling the realization of a high-rigidity, high-hardness end mill with a smaller diameter and a longer cutting length.

Description

Technical Field

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

[0002] As one of the most commonly used rotary cutting tools in the machining field, milling cutters are widely used in machining scenarios such as planar milling, cavity milling, contour milling, and slot milling in industries such as mold manufacturing, aerospace, automotive parts, and general machinery. With the continuous improvement of the requirements of modern manufacturing industry for machining efficiency, machining accuracy, and tool life, the cutting performance of milling cutters is facing increasingly stringent challenges.

[0003] In existing milling cutter technology, the cutting part is usually made of a single material, mainly divided into two categories: carbide milling cutters and high-speed steel milling cutters. Carbide milling cutters have high hardness and wear resistance, and can maintain good cutting sharpness and dimensional accuracy. However, carbide materials are relatively brittle and have low fracture toughness. Under conditions such as intermittent cutting, high feed rate cutting, or workpieces with uneven material, edge chipping or even tool body breakage is likely to occur, especially when milling high-hardness materials or subjected to impact loads. Although high-speed steel milling cutters have good toughness and impact resistance, their hardness and wear resistance are significantly insufficient. In high-speed cutting or long-term continuous machining, the cutting edge wears quickly, resulting in shortened tool life, deterioration of machined surface quality, and the need for frequent tool changes and resetting, which reduces production efficiency and increases operating costs. Summary of the Invention

[0004] The purpose of this invention is to address the technical problems existing in the background art by proposing a novel end mill.

[0005] To achieve the above-mentioned technical objectives, the technical solution adopted by the present invention is as follows: A novel milling cutter includes a shank and a cutting section. The cutting section is connected to the shank and extends along the axial direction of the shank. The cutting section includes at least one cutter body and at least one discharge groove. The cutter body and the discharge groove are arranged adjacent to each other and spirally arranged along the axis of the cutting section. A milling cutting edge is provided at the end of the cutter body away from the shank. The cutting section is made of a composite material, which includes an ultrahard part and a rigid part. The connection between the ultrahard part and the rigid part forms a boundary surface. The boundary surface coincides with or forms an angle with the axis of the cutting section. The portion covered by the ultrahard part includes the milling cutting edge, while the portion covered by the rigid part does not include the milling cutting edge.

[0006] Preferably, the boundary surface includes a flat surface.

[0007] Preferably, the angle between the boundary surface and the axis of the cutting part is in the range of 0 to 60 degrees.

[0008] Preferably, both the ultra-hard portion and the rigid portion cover the portion of the cutter body and the portion of the discharge groove.

[0009] Preferably, the proportion of the ultrahard portion in the cutting section is equal to or less than the proportion of the rigid portion.

[0010] Preferably, the ultra-hard part is PCD or PCBN, and the rigid part is an alloy material.

[0011] Preferably, the boundary surface is on the side away from the bar, and the axis of the cutting part is at the end point away from the bar.

[0012] Preferably, there are two cutter bodies, which are symmetrical about the axis of the cutting part.

[0013] Compared with the prior art, the invention has the following beneficial technical effects: It includes a shank and a cutting part, the cutting part is connected to the shank and extends along the axial direction of the shank, the cutting part includes at least one cutter body and at least one discharge groove, the cutter body and the discharge groove are arranged adjacent to each other and spirally arranged along the axis of the cutting part, a milling edge is provided at the end of the cutter body away from the shank, the cutting part is made of composite material, the composite material includes an ultra-hard part and a rigid part, the connection between the ultra-hard part and the rigid part forms a boundary surface, the boundary surface coincides with or is at an angle to the axis of the cutting part, the part covered by the ultra-hard part includes the milling edge, the part covered by the rigid part does not include the milling edge, by concentrating the ultra-hard part at the milling edge and the rigid part at the non-milling edge, the new milling cutter has an ultra-hard cutting edge and a high-rigidity shank, thereby enabling the realization of a high-rigidity and high-hardness milling cutter with a smaller diameter and a longer cutting length. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of a single-flute end mill in the embodiments provided by the present invention. Figure 1 ; Figure 2 for Figure 1 Enlarged view of part A in the middle; Figure 3 This is a schematic diagram of a single-flute end mill in the embodiments provided by the present invention. Figure 2 ; Figure 4 This is a schematic diagram of a double-edged end mill in the embodiments provided by the present invention. Figure 1 ; Figure 5 for Figure 4 Enlarged view of part B in the middle; Figure 6 This is a schematic diagram of a double-edged end mill in the embodiments provided by the present invention. Figure 2 .

[0015] Icon labels: 100 pole section; 200 Cutting section, 201 Tool body, 2011 Milling edge, 202 Material discharge groove; 300 superhard portion; 400 rigid section; 500 boundary surface. Detailed Implementation

[0016] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0017] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or assembly 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 the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more features. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0018] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a link, or a specific 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 connection within two groups. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0019] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0020] like Figures 1-6 As shown, the present invention proposes a novel milling cutter, including a shank 100 and a cutting portion 200, wherein the cutting portion 200 is connected to the shank 100 and extends along the axial direction of the shank 100.

[0021] It should be noted that the rod 100, as a clamping and transmission component, has a cross-sectional form including but not limited to cylindrical straight shank, Morse taper shank, or BT / HSK interface, etc., and its interior can be designed as a solid or hollow internal cooling channel structure. The cutting part 200, as the working section that directly participates in material removal, has a cutting edge that can be straight, spiral, or variable spiral angle, and the number of cutting edges can be single or multiple. The chip removal groove can be a straight groove, spiral groove, or parabolic groove, etc., and the bottom cutting edge can be flat, rounded, or spherical. The connection method between the rod 100 and the cutting part 200 can be integral grinding, brazing, mechanical connection, thermal interference fit, or bonding, etc. The two can use different material combinations to achieve functional complementarity.

[0022] The cutting part 200 includes at least one cutter body 201 and at least one discharge groove 202. The cutter body 201 and the discharge groove 202 are arranged adjacent to each other and spirally arranged along the axis of the cutting part 200. A milling edge 2011 is provided at the end of the cutter body 201 away from the shank 200. The cutting part 200 is made of composite material, which includes an ultra-hard part 300 and a rigid part 400. A boundary surface 500 is formed at the junction of the ultra-hard part 300 and the rigid part 400. The boundary surface 500 coincides with or forms an angle with the axis of the cutting part 200. The part covered by the ultra-hard part 300 includes the milling edge 2011, and the part covered by the rigid part 400 does not include the milling edge 2011.

[0023] It should be noted that the cutter body 201 is the main solid structure for milling, and the discharge groove 202 is a chip removal channel. The cutter body 201 and the discharge groove 202 are arranged adjacent to each other and are spirally distributed along the axis of the cutting part 200. This spiral layout can achieve progressive entry to reduce cutting impact, improve chip removal continuity and improve the surface quality of the machined part. Its helix angle can be designed as a constant helix angle or a variable helix angle. The ratio of the number of cutter bodies 201 to discharge grooves 202 can be single-edge single groove, double-edge double groove or even multi-edge multi-groove. Increasing the number of edges can improve feed efficiency but will compress the chip removal space. The cross-sectional shape of the discharge groove 202 can be straight groove, spiral groove, variable cross-section or parabolic, etc. Among them, the parabolic groove is suitable for deep cavity and deep groove machining. The depth and width of the discharge groove can be varied along the axial direction to optimize the chip removal performance of different cutting sections.

[0024] The cutting part 200 is composed of an ultra-hard part 300 and a rigid part 400 connected together. The two materials form a boundary surface 500 at the connection point. This boundary surface has two geometric relationships with the axis of the cutting part: it coincides with the axis or forms an angle. When it coincides with the axis, the two materials are distributed in half along the axis. When it forms an angle, the angle can be optimized according to the cutting force direction and stress distribution requirements. The connection method can be brazing, diffusion welding, laser welding, friction welding, mechanical inlay or bonding, etc. The angle, position and shape of the boundary surface 500 can be used as design variables, which provides full flexibility for customized optimization of the tool structure under different machining conditions.

[0025] It should be noted that the composite material consists of two parts: an ultra-hard part 300 and a rigid part 400, which form a boundary surface 500 at the interface. The orientation of the boundary surface 500 can coincide with (i.e., parallel to) the axis of the cutting part 200 or form a certain angle with the axis. The material distribution can be optimized according to different working conditions, making the partitioning method of the hard part 300 and the rigid part 400 flexible in design. The ultra-hard part 300 covers the area where the milling edge 2011 is located to ensure that the cutting edge has extremely high hardness and wear resistance, while the area covered by the rigid part 400 does not include the milling edge, thus providing the milling cutter with sufficient toughness and impact resistance. The size of the angle between the boundary surface 500 and the axis can affect the stress distribution. When the angle is zero, a straight transition is achieved. When the angle is not zero, staggered engagement can be achieved to enhance the bonding force. In addition, the helix angle and number of the cutter body 201 and the discharge groove 202, as well as the coverage depth of the ultra-hard part, can be specifically optimized according to the material being processed, thereby achieving the best balance between wear resistance, toughness and chip removal efficiency.

[0026] In one embodiment of this application, the boundary surface 500 includes a flat surface.

[0027] It should be noted that the boundary surface 500 includes a flat surface, that is, the interface between the ultra-hard part 300 and the rigid part 400 is a plane, rather than a curved surface, stepped surface, sawtooth surface, toothed meshing surface or other irregular contour surface. This flat surface design has significant advantages in terms of manufacturing process. The flat surface is easy to prepare accurately by conventional processing methods such as grinding, milling or wire cutting. The processing accuracy and surface roughness are highly controllable. At the same time, in joining processes such as brazing, diffusion welding, laser welding or friction welding, the flat joint surface is conducive to achieving uniform solder spreading, stable welding pressure distribution and consistent metallurgical bonding quality, thereby improving the bonding strength and batch consistency of the joint interface.

[0028] Of course, the design of the 500 boundary surface is not limited to a flat surface. It can be an arc-shaped surface to increase the bonding area and improve the transmission path of cutting force, a stepped surface or multi-step surface to introduce mechanical interlocking effect to enhance the interface's shear resistance, a serrated surface or toothed surface to superimpose geometric constraint force on the basis of welding bonding force, a wavy surface to improve the interface's resistance to fatigue crack propagation, or different forms of connection interfaces can be used in different sections of the same milling cutter to achieve differentiated optimization of local performance, providing ample design space for tool optimization under different material combinations and different machining conditions.

[0029] In one embodiment of this application, the angle e between the boundary surface 500 and the axis of the cutting portion 200 ranges from 0 to 60 degrees.

[0030] In one embodiment of this application, both the ultrahard portion 300 and the rigid portion 400 cover portions of the cutter body 201 and the discharge groove 202.

[0031] It should be noted that both materials simultaneously cover a portion of the cutter body 201 and a portion of the discharge groove 202, rather than classifying the cutter body and the discharge groove as separate materials. This means that the boundary surface 500 of the two materials runs through the junction area of ​​the cutter body and the discharge groove, allowing each material to participate in both the structural load-bearing function of the cutter body and the chip-removing and guiding function of the discharge groove.

[0032] The portion covered by the superhard part 300 explicitly includes the milling edge 2011 of the tool body 201. Therefore, the superhard part 300 is made of a high-hardness, high-wear-resistant material and is placed in the area of ​​the milling edge 2011 that directly participates in cutting. This allows the milling edge 2011 to obtain optimal wear resistance and cutting edge retention during the cutting process. The rigid part 400 covers the rest of the tool body and the chute, providing the necessary toughness and impact resistance. Both materials span the two functional areas of the tool body and the chute, rather than being simple geometric partitions. This means that the boundary surface 500 must cross the solid section of the tool body and the cavity boundary of the chute in cross-section, forming a complex interface profile. While covering the milling edge 2011, the superhard part 300 can also extend further into the rake face area of ​​the chute adjacent to the milling edge 2011 to ensure that the chip removal surface that the chip initially contacts after leaving the milling edge 2011 also has high wear resistance, avoiding wear grooves caused by the chip in this transition area to the softer rigid part.

[0033] In one embodiment of this application, the proportion of the ultrahard portion 300 in the cutting portion 200 is equal to or less than the proportion of the rigid portion 400.

[0034] In one embodiment of this application, the ultra-hard portion 300 is a PCD or PCBN.

[0035] It should be noted that PCD is polycrystalline diamond and PCBN is polycrystalline cubic boron nitride, both of which possess superhard properties. Of course, the superhard part 300 also includes ceramic matrix composites, etc. The rigid part 400 includes, but is not limited to, cemented carbide, high-speed steel, or cermet. The main structure of the cutting part 200 is composed of the rigid part 400, while the superhard part 300 exists only as a local functional coating layer or a reinforcing component for the cutting edge area. Controlling the proportion of the superhard part 300 to less than 50% can significantly reduce the material cost of the tool, making this dual-material solution economically competitive with traditional one-piece tools. The rigid part 400 occupying the main body of the cutting part 200 can ensure that the tool body as a whole has good bending strength and impact toughness, avoiding overall brittle fracture of the tool under intermittent cutting or uneven load due to excessive brittle material proportion.

[0036] In one embodiment of this application, the boundary surface 500 is located on the side away from the rod 100, adjacent to the axis of the cutting portion 200 at the end point away from the rod 100.

[0037] See appendix Figure 2 It should be noted that the boundary surface 500 converges towards the axis of the cutting part 200 and is close to the axis at the end far from the shank 100. In the area of ​​the cutting part 200 near the shank 100, the boundary surface 500 is closer to the outer circumferential surface. The superhard part 300 covers the cutting edge 2011 area of ​​the outer edge of the tool body 201. As it extends towards the tip of the tool, the boundary surface 500 gradually bends or tilts towards the axis, converging at the tip of the tool to a position that is almost tangent to or very close to the axis. This ensures that the superhard part 300 covers the complete cutting surface from the outer circumferential cutting edge to the center area of ​​the bottom cutting edge at the tip of the tool. This ensures that all surfaces of the tool tip that participate in cutting are made of high-hardness and wear-resistant materials, thereby preventing the rigid part 400 from being directly exposed to cutting contact in the center area of ​​the bottom cutting edge of the tool tip, which could lead to premature wear or chipping.

[0038] In one embodiment of this application, two cutter bodies 201 are provided, and the two cutter bodies 201 are symmetrical about the axis of the cutting part 200.

[0039] See appendix Figure 4 It should be noted that the two cutter bodies 201 are symmetrical about the axis of the cutting part 200. That is, the two cutter bodies 201 are arranged at 180° intervals on the cross-section of the cutting part with the axis as the center of symmetry, forming a symmetrical structure of double-edged double-discharge grooves. The 180° symmetrical distribution of the two cutter bodies allows the two cutting edges to participate in cutting alternately during the cutting process. The radial cutting forces can theoretically cancel each other out, which significantly reduces the off-center radial force on the spindle and the tool. This is beneficial to improving machining stability, reducing vibration and improving surface quality. The double-edged structure usually corresponds to two discharge grooves 202. The two discharge grooves provide ample chip removal space and cutting fluid channels. Compared with multi-edged end mills, they have superior chip removal capabilities and are less prone to chip clogging and secondary cutting.

[0040] The core region formed by the rigid part between the two cutter bodies 201 can provide sufficient structural cross-sectional area to ensure that the cutting part as a whole has good bending and torsional rigidity. This centrally symmetrical layout also forms a good geometric fit with the spatial design of the aforementioned boundary surface 500. The milling edges 2011 of the two cutter bodies 201 are covered by the superhard part 300. Under the condition of symmetrical distribution, the boundary surface 500 can be unfolded in a symmetrical configuration on both sides of the axis, so that the distribution of the superhard part 300 is symmetrical, which is conducive to controlling manufacturing consistency.

[0041] Based on this, it can be further expanded. The number of cutting tools is not limited to two. It can be designed as three-bladed (120° evenly distributed) to improve feed efficiency and machining stability, four-bladed (90° evenly distributed) to achieve a balance between chip removal and efficiency, or six-bladed or more to achieve high-efficiency finishing.

[0042] It should be noted that the above descriptions are one or more embodiments provided in conjunction with specific content, and do not imply that the specific implementation of the present invention is limited to these descriptions. Any methods or structures that are similar to or identical to those of the present invention, or any technical deductions or substitutions made based on the concept of the present invention, should be considered within the scope of protection of the present invention.

Claims

1. A novel end mill, characterized in that, include: pole section; A cutting portion is connected to the rod portion and extends along the axial direction of the rod portion; The cutting part includes at least one cutter body and at least one discharge groove. The cutter body is arranged adjacent to the discharge groove and spirally arranged along the axis of the cutting part. A milling edge is provided at the end of the cutter body away from the shank. The cutting part is made of a composite material, which includes an ultrahard part and a rigid part. The connection between the ultrahard part and the rigid part forms a boundary surface. The boundary surface coincides with or forms an angle with the axis of the cutting part. The portion covered by the ultrahard part includes the milling cutting edge, and the portion covered by the rigid part does not include the milling cutting edge.

2. The novel end mill according to claim 1, characterized in that, The boundary surface includes a flat surface.

3. A novel end mill according to claim 2, characterized in that, The angle between the boundary surface and the axis of the cutting part ranges from 0 to 60 degrees.

4. A novel milling cutter according to claim 3, characterized in that, Both the ultrahard portion and the rigid portion cover portions of the blade body and the discharge groove.

5. A novel end mill according to claim 4, characterized in that, In the cutting section, the proportion of the ultra-hard portion is equal to or less than the proportion of the rigid portion.

6. A novel milling cutter according to claim 5, characterized in that, The ultra-hard component is PCD or PCBN.

7. A novel end mill according to claim 3, characterized in that, The boundary surface is located on the side away from the rod, adjacent to the axis of the cutting part at the end point away from the rod.

8. A novel end mill according to claim 1, characterized in that, The blade body is provided in two parts, and the two blade bodies are symmetrical about the axis of the cutting part.

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