A PCD left-hand cutter

Abstract

The utility model discloses a PCD left hand milling cutter, it includes handle and is located handle one end mirror image symmetry's two chip pockets, two chip pockets opposite one side all are equipped with blade, and the blade has bottom blade and left hand cutter blade, two blades opposite one side all are equipped with protective layer, and protective layer covers bottom blade and left hand cutter blade. Because protective layer completely covered the cutting position of bottom blade and left hand cutter blade, in the processing, because protective layer covered all cutting edges first, so that workpiece first contact is protective layer and not direct contact blade, can effectively avoid bottom blade and left hand cutter blade's cusp in the processing because of friction wear and lead to the problem such as processing precision decline, surface quality bad of poor quality, thereby significantly improved the qualified rate of processing product and the service life of cutting tool, simultaneously, the covering of protective layer also played the role of even dispersion cutting force, further promoted the processing stability.

Description

Technical Field

[0001] This utility model relates to the field of PCD left-hand end mills, and in particular to a PCD left-hand end mill. Background Technology

[0002] The limitations of traditional carbide end mills in machining high-hardness materials are mainly reflected in the following aspects: First, because the hardness and red hardness of carbide tools are difficult to match the high hardness characteristics of the materials being machined, failure modes such as rapid dulling of the cutting edge and crater wear will occur during high-speed cutting. This not only leads to a significant reduction in tool life to 1 / 3 to 1 / 5 of that in conventional machining, but also increases machine tool downtime due to frequent tool changes, significantly reducing machining efficiency and increasing the cost per unit.

[0003] More notably, in special working conditions such as thin-walled casing parts in the aerospace field, weakly rigid bone plate structural parts in medical devices, or high-precision mirror surface machining of optical molds, the helical groove design of conventional right-hand end mills will generate periodic cutting vibrations at a specific frequency.

[0004] This vibration can induce the following problems: chatter causes the cutting force to fluctuate by more than 30%, resulting in regular chatter marks with a spacing of 0.05-0.2mm on the workpiece surface; the tool deflection effect causes the actual cutting depth to deviate from the set value by 5-10μm, which seriously affects the critical dimensions and the surface roughness deteriorates to Ra1.6μm or more, which cannot meet the requirements for high surface finish.

[0005] While the current mainstream polycrystalline diamond (PCD) end mills have significantly better hardness and thermal conductivity than cemented carbide, their product design still has obvious flaws: more than 90% of PCD end mills use the traditional right-hand helical structure and have not optimized the flute design according to the anisotropic characteristics of PCD material; left-hand helical structure products account for less than 5%, and there is a lack of special helix angle and cutting edge treatment solutions for different materials; in actual machining, abnormal wear at the tip radius can cause burrs exceeding 5μm on the edge of workpieces machined in silicon-aluminum alloys, or cause delamination defects in carbon fiber composites; in the machining of thin-walled components in aerospace, the vibration caused by insufficient rigidity of existing PCD end mills can increase the roundness error of the workpiece. These problems seriously restrict the application potential of PCD tools in high-precision and high-efficiency machining fields. Utility Model Content

[0006] In view of this, the present invention addresses the deficiencies of the existing technology, and its main objective is to provide a PCD left-hand end mill that solves the aforementioned problems.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: a left-hand end mill, including a shank and two chip grooves that are mirror-symmetrically arranged at one end of the shank. Each chip groove has an insert on its opposite side. The insert has a bottom cutting edge and a left-hand cutting edge. Each insert has a protective layer on its opposite side, and the protective layer covers the bottom cutting edge and the left-hand cutting edge.

[0008] Furthermore, when viewed from above, the tool holder has a blurred axis line with the tool holder axis as a reference, which extends radially and passes through the two protective layers.

[0009] Furthermore, one end of the bottom cutting edge protrudes from the handle, and a chip-retaining space is provided between the end face of the protruding end of the bottom cutting edge and the adjacent end face of the handle.

[0010] Furthermore, one side of the left-handed blade protrudes beyond the outer contour of the handle.

[0011] Furthermore, the end face of the protruding end of the bottom blade is inclined, and the axial inclination angle is 5°.

[0012] Furthermore, the protective layer is inclined on one side of the protruding end face of the bottom blade, and the axial inclination angle is 15°.

[0013] Furthermore, the left-handed cutting edge protrudes from one side of the outer contour of the handle at an angle of 7° relative to the radial angle of the axis.

[0014] Furthermore, the protective layer is inclined on the side corresponding to the protruding left-hand cutting edge, and the radial inclination angle relative to the axis is 20°.

[0015] Furthermore, the tool holder includes a first part and a second part, the diameter of the first part is smaller than that of the second part, and there is a step difference between the two. Chip grooves and cutting blades are provided on the first part.

[0016] Furthermore, the left-handed cutting edge extends radially along the step edge and is parallel to the second part surface.

[0017] Compared with the prior art, this utility model has obvious advantages and beneficial effects. Specifically, as can be seen from the above technical solution, because the protective layer completely covers the cutting parts of the bottom edge and the left-hand cutting edge, during the processing, since the protective layer preferentially covers all cutting edges, the workpiece first contacts the protective layer rather than directly contacts the cutting edge. This can effectively avoid problems such as decreased processing accuracy and poor surface quality caused by friction and wear of the bottom edge and the left-hand cutting edge during the processing, thereby significantly improving the pass rate of processed products and the service life of the tool. At the same time, the coverage of the protective layer also plays a role in uniformly dispersing the cutting force, further improving the processing stability.

[0018] To more clearly illustrate the structural features and effects of this utility model, the following detailed description of this utility model is provided in conjunction with the accompanying drawings and specific embodiments. Attached Figure Description

[0019] Figure 1 This is a perspective view of Embodiment 1 of this utility model.

[0020] Figure 2 This is a first-view view of the handle of Embodiment 1 of this utility model.

[0021] Figure 3 This is a second-view view of the handle of Embodiment 1 of this utility model.

[0022] Figure 4 This is a third-view view of the handle of Embodiment 1 of this utility model.

[0023] Explanation of reference numerals in the attached diagram: Tool holder 10, first part 10a, second part 10b, step 10c, chip groove 11; PCD blade 20, bottom edge 21, left-hand cutting edge 22; Protective layer 30; Chip space 40; Centerline A. Detailed Implementation

[0024] Please refer to Figure 1-4 As shown, this invention illustrates the specific structure of a preferred first embodiment of a PCD left-hand end mill, comprising a shank 10 and two mirror-symmetrical chip grooves 11 located at one end of the shank 10. Each chip groove 11 has a PCD insert 20 on its opposite side. Each PCD insert 20 has a bottom cutting edge 21 and a left-hand cutting edge 22. A protective layer 30 is provided on the opposite side of each PCD insert 20, covering both the bottom cutting edge 21 and the left-hand cutting edge 22. Because the protective layer 30 completely covers the cutting areas of the bottom cutting edge 21 and the left-hand cutting edge 22, during machining, the workpiece first contacts the protective layer 30 rather than directly contacting the cutting edge, effectively preventing problems such as decreased machining accuracy and poor surface quality caused by friction and wear of the bottom cutting edge 21 and the left-hand cutting edge 22 during machining. This significantly improves the yield rate of machined products and the service life of the tool. Simultaneously, the protective layer 30 also evenly disperses the cutting force, further enhancing machining stability.

[0025] In addition, the left-hand groove design of the chip groove 11 allows the PCD insert 20 to work with the downward cutting force, reducing workpiece vibration, which is especially suitable for machining thin-walled parts and achieving high-finish cutting.

[0026] It should be noted that the PCD insert 20 is made of polycrystalline diamond, which gives it high strength, high sharpness, and long service life, greatly reducing the number of tool changes.

[0027] In one example, the cutting edges of the bottom edge 21 and the left-hand cutting edge 22 are laser-machined, and the surface roughness is ≤Ra0.2μm. In addition, the cutting edges of the bottom edge 21 and the left-hand cutting edge 22 are rounded, and the width is controlled between 0.003 and 0.005μm.

[0028] For example, when viewed from above, the tool holder 10 has a virtual axis line A with the axis of the tool holder 10 as a reference. The axis line A extends radially and passes through the two protective layers 30. The coverage of the protective layers 30 is strictly symmetrically distributed in the circumferential direction, so that the cutting force on both sides can be evenly balanced when the tool is rotating at high speed, thereby effectively improving the machining stability and reducing vibration.

[0029] It should be noted that axis line A is a blurred reference line.

[0030] For example, one end of the bottom cutting edge 21 protrudes from the tool holder 10, and a chip-receiving space 40 is provided between the end face of the protruding end of the bottom cutting edge 21 and the adjacent end face of the tool holder 10. When the bottom cutting edge 21 makes cutting contact with the workpiece material, the sufficient chip-receiving space 40 can promptly remove the generated chip profiles (including ribbon chips, broken chips, etc.) from the cutting area, thereby avoiding the common phenomenon of chip adhesion during machining, preventing secondary scratches of the machined surface by chips, reducing the decrease in surface finish caused by chip accumulation, and avoiding local temperature rise of the tool caused by chip accumulation, ultimately ensuring that the workpiece obtains a uniform and high-quality machined surface.

[0031] The left-handled blade 22 protrudes from one side of the outer contour of the handle 10.

[0032] The end face of the protruding end of the bottom blade 21 is inclined, and the axial inclination angle is 5°.

[0033] The protective layer 30 is inclined on one side of the protruding end face of the bottom blade 21, and the axial inclination angle is 15°.

[0034] The left-hand cutting edge 22 protrudes from one side of the outer contour of the handle 10 and is inclined, with a radial inclination angle of 7° relative to the axis A.

[0035] The protective layer 30 is inclined to the side of the left-hand cutting edge 22 that protrudes, and the radial inclination angle relative to the axis A is 20°.

[0036] The tool holder 10 includes a first part 10a and a second part 10b. The diameter of the first part 10a is smaller than that of the second part 10b, and there is a step difference 10c between them. The chip groove 11 and the PCD cutting tool 20 are provided on the first part 10a.

[0037] The left-hand cutting edge 22 extends radially along the edge of the step 10c and is parallel to the surface of the second part 10b.

[0038] The above description is merely a preferred embodiment of the present utility model and does not constitute any limitation on the technical scope of the present utility model. Therefore, any minor modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present utility model shall still fall within the scope of the technical solution of the present utility model.

Claims

1. A PCD left-hand milling cutter characterised in that: The tool includes a handle (10) and two chip grooves (11) that are mirror-symmetrically arranged at one end of the handle (10). Each of the two chip grooves (11) has a PCD blade (20) on its opposite side. The PCD blade (20) has a bottom edge (21) and a left-hand cutting edge (22). Each of the two PCD blades (20) has a protective layer (30) on its opposite side, and the protective layer (30) covers the bottom edge (21) and the left-hand cutting edge (22).

2. The PCD left-hand cutter of claim 1, wherein: When viewed from above, the tool holder (10) has a virtual axis line (A) with the axis of the tool holder (10) as a reference. The axis line (A) extends radially and passes through the two protective layers (30).

3. The PCD left-hand end mill according to claim 1, characterized in that: One end of the bottom cutting edge (21) protrudes from the handle (10), and a chip-retaining space (40) is provided between the end face of the protruding end of the bottom cutting edge (21) and the end face of the adjacent handle (10).

4. The PCD left-hand cutter of claim 2, wherein: The left-handed blade (22) protrudes from the outer contour of the handle (10) on one side.

5. The PCD left-hand cutter of claim 3, wherein: The end face of the protruding end of the bottom blade (21) is inclined, and the axial inclination angle is 5°.

6. A PCD left-hand cutter according to claim 5, wherein: The protective layer (30) is inclined on one side of the protruding end face of the bottom edge (21), and the axial inclination angle is 15°.

7. The PCD left-hand cutter of claim 4, wherein: The left-handed cutting edge (22) protrudes from one side of the outer contour of the handle (10) and is inclined, with a radial inclination angle of 7° relative to the axis (A).

8. The PCD left-hand cutter of claim 7, wherein: The protective layer (30) is inclined to the side of the left-hand cutting edge (22) and has a radial inclination angle of 20° relative to the axis (A).

9. The PCD left-hand cutter of claim 1, wherein: The tool holder (10) includes a first part (10a) and a second part (10b), the first part (10a) having a smaller diameter than the second part (10b) and a step (10c) between them, the chip groove (11) and the PCD blade (20) being provided on the first part (10a).

10. The PCD left-hand cutter of claim 9, wherein: The left-handed cutting edge (22) extends radially along the edge of the step (10c) and is parallel to the surface of the second part (10b).

Images