A cutting tool and a cutting head structure thereof

Abstract

The present invention relates to the field of precision machining technology, and discloses a cutting tool and a tool head structure thereof, wherein the tool head structure comprises a cutting edge portion, and the cutting edge portion comprises a cutting body, wherein the outer surface of the cutting body is a forwardly convex arc surface, and the outer surface of the cutting body is provided with a first cutting edge and at least two second cutting edges, wherein the first cutting edge extends from one side of the cutting body to its top area, and then extends to the other side of the cutting body, and each of the second cutting edges is respectively provided on both sides of the first cutting edge, and a first chip removal groove is defined between the first cutting edge and the second cutting edge adjacent thereto, and the width of the first chip removal groove gradually increases from the top area of ​​the cutting body to both ends. The beneficial effects of the present invention are: high machining accuracy, high machining stability, good chip removal performance, and the service life of the tool can be greatly extended.

Description

Technical Field

[0001] The invention relates to the technical field of precision machining, and in particular to a cutting tool and a tool head structure thereof. Background Art

[0002] At present, a main cutting edge is arranged at the top center point of a conventional spherical milling cutter. When milling a curved surface, the surface material of the workpiece is removed by extrusion or cutting at the vertex of the main cutting edge. However, due to the concentrated force at the vertex, the main cutting edge at the vertex of the tool is greatly worn, and the service life of the tool is limited. When batch processing workpieces, the processing is unstable, and the surface roughness and contour of each workpiece are unstable. To address this problem, secondary cutting edges can be arranged on both sides of the main cutting edge to assist the main cutting edge in cutting and extrusion. However, since the cutting edges are densely packed in the top area of ​​the tool, the chip discharge is not smooth, which not only concentrates the processing heat, but also greatly affects the processing accuracy and processing stability of the workpiece. Summary of the invention

[0003] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a cutting tool that can reduce tool wear to extend the tool life, ensure the surface roughness of the machined workpiece, improve machining stability, and enhance chip removal performance.

[0004] In order to achieve the above-mentioned object, a first aspect of the present invention provides a tool head structure, which includes a cutting edge portion, wherein the cutting edge portion includes a cutting body, wherein the outer surface of the cutting body is a forward convex arc surface, and the outer surface of the cutting body is provided with a first cutting edge and at least two second cutting edges,

[0005] The first cutting edge extends from one side of the cutting body to its top area, and then extends to the other side of the cutting body. The second cutting edges are respectively arranged on both sides of the first cutting edge. A first chip groove is defined between the first cutting edge and the second cutting edge adjacent thereto. The width of the first chip groove gradually increases from the top area of ​​the cutting body to both ends.

[0006] As a preferred solution, the first cutting edge passes through the vertex of the cutting body, and the cutting body is symmetrically distributed about the first cutting edge.

[0007] As a preferred solution, each of the second cutting edges is symmetrically distributed with respect to the first cutting edge.

[0008] As a preferred solution, the second cutting edge is in an arc shape protruding toward the first cutting edge.

[0009] As a preferred solution, the second cutting edge includes a first cutting segment and a second cutting segment, the first cutting segment extends from one side of the cutting body to the top region thereof and then is connected to one end of the second cutting segment, and the second cutting segment extends from the top region of the cutting body to the other side of the cutting body;

[0010] The first cutting segment and the second cutting segment are both spiral-shaped, and the rotation direction of the first cutting segment is opposite to that of the second cutting segment.

[0011] As a preferred solution, the helix angles of the first cutting segment and the second cutting segment are both 0-80°.

[0012] As a preferred solution, a second cutting edge is respectively provided on both sides of the first cutting edge.

[0013] As a preferred solution, the diameter of the cutting body is 0.2 mm to 20 mm, the width of the first cutting edge and the second cutting edge is 0.005 mm to 0.2 mm, and the depth of the first chip groove is 0.05 mm to 1 mm.

[0014] As a preferred solution, the cutting body, the first cutting edge and the second cutting edge are integrally formed.

[0015] As a preferred embodiment, the outer surface of the cutting body is also provided with a plurality of third cutting edges, each of which is arranged on the outer side of the two outermost second cutting edges, and a second chip groove is defined between two adjacent third cutting edges and between the third cutting edge and the second cutting edge adjacent thereto.

[0016] As a preferred solution, the third cutting edges are symmetrically distributed with respect to the first cutting edge.

[0017] As a preferred solution, each of the third cutting edges is spiral-shaped.

[0018] As a preferred embodiment, the third cutting edges located on the same side of the first cutting edge form a cutting edge group, the cutting edge group is a symmetrical structure, and the third cutting edges located on one side of the symmetry center line of the cutting edge group have opposite rotation directions to the third cutting edges located on the other side of the symmetry center line of the cutting edge group.

[0019] As a preferred solution, the helix angle of the third cutting edge is 0-80°, and the helix angle of each third cutting edge in the cutting edge group gradually decreases from both sides to the middle.

[0020] As a preferred solution, one end of the third cutting edge is connected to the second cutting edge, and the other end of the third cutting edge is arranged on the outer surface of the cutting body.

[0021] As a preferred solution, the outer surface of the cutting body is hemispherical.

[0022] As a preferred solution, the material of the cutting edge portion is any one of polycrystalline diamond, single crystal diamond, chemical vapor deposited diamond, polycrystalline cubic boron nitride, ceramic and cemented carbide.

[0023] As a preferred solution, the cutter head structure further comprises a connecting portion, and the rear end surface of the cutting body is connected to the front end of the connecting portion.

[0024] As a preferred solution, the cutting edge portion and the connecting portion are made of the same material, and the cutting edge portion and the connecting portion are integrally formed.

[0025] For the same purpose, the second aspect of the present invention further proposes a cutting tool, which includes a tool shank and a tool head structure as described in any one of the first aspects, wherein the rear end face of the cutting body is connected to the front end of the tool shank.

[0026] Compared with the prior art, the cutting tool of the embodiment of the present invention has the following beneficial effects:

[0027] The cutting tool of the embodiment of the present invention is provided with a first cutting edge and a second cutting edge respectively arranged on both sides of the first cutting edge on the outer surface of the cutting body, wherein the first cutting edge extends from one side of the cutting body to the top area and then to the other side; during the milling process, the second cutting edge performs cutting action to remove most of the excess, and the remaining smaller processing excess is squeezed and processed by the first cutting edge, which has the nature of rough processing first and then fine processing, can effectively improve the processing accuracy, and reduce the wear of the first cutting edge to extend the service life of the first cutting edge; furthermore, the width of the first chip groove defined between the second cutting edge and the first cutting edge gradually increases from the top area of ​​the cutting body to the two ends, which can optimize the chip removal capacity and avoid the accumulation of waste chips in the top area of ​​the cutting body to cause adverse effects on the forming accuracy and tool life. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a structural schematic diagram of a cutter head structure in Embodiment 1 of the present invention;

[0029] Figure 2 yes Figure 1 A top view of

[0030] Figure 3 yes Figure 2 Left view of

[0031] Figure 4 is a structural schematic diagram of a cutter head structure in Embodiment 2 of the present invention;

[0032] Figure 5It is a schematic structural diagram of a cutting tool in an embodiment of the present invention.

[0033] In the figure, 100, a cutter head structure; 1, a connecting portion; 2, a cutting edge portion; 21, a cutting body; 22, a first cutting edge; 23, a second cutting edge; 231, a first cutting segment; 232, a second cutting segment; 24, a first chip groove; 25, a cutting edge group; 251, a third cutting edge; 26, a second chip groove; 27, a third chip groove;

[0034] 200. Tool handle. DETAILED DESCRIPTION

[0035] The specific implementation of the present invention is further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0036] In the description of the present invention, it should be understood that the terms "front" and "rear" used in the present invention refer to the end of the cutting tool close to the workpiece during use as the "front" and the end away from the workpiece as the "rear".

[0037] In addition, it should be pointed out that the term "vertex of the cutting body" in the present invention refers to the position on the outer surface of the cutting body that is farthest from the tool shank during use of the cutting tool, and "top area of ​​the cutting body" refers to the area on the outer surface of the cutting body that includes the vertex of the cutting body and is closer to the vertex of the cutting body.

[0038] It should be understood that the present invention uses the terms "first", "second", etc. to describe various information, but these information should not be limited to these terms, and these terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of the present invention, "first" information may also be referred to as "second" information, and similarly, "second" information may also be referred to as "first" information.

[0039] The first aspect of the present invention provides a cutter head structure, and the specific implementation is as follows:

[0040] Embodiment 1

[0041] like Figures 1 to 3 As shown, a tool head structure 100 of a preferred embodiment of the present invention comprises a connecting portion 1 and a cutting edge portion 2 provided at the front end of the connecting portion 1, wherein the cutting edge portion 2 comprises a cutting body 21 fixed at the front end of the connecting portion 1, wherein the outer surface of the cutting body 21 is an arc surface convex outward, and the outer surface of the cutting body 21 is provided with a first cutting edge 22 and at least two second cutting edges 23,

[0042] The first cutting edge 22 extends from one side of the cutting body 21 to its top area, and then extends to the other side of the cutting body 21. The second cutting edges 23 are respectively arranged on both sides of the first cutting edge 22. A first chip groove 24 is defined between the first cutting edge 22 and the second cutting edge 23 adjacent thereto. The width of the first chip groove 24 gradually increases from the top area of ​​the cutting body 21 to both ends.

[0043] Based on the above technical solution, the cutter head structure 100 is provided with a first cutting edge 22 and a plurality of second cutting edges 23. Figure 2 A top view of the tool head structure 100 is shown. From the top view, the first cutting edge 22 passes through the central area of ​​the cutting body 21 and includes two second cutting edges 23. Each second cutting edge 23 is respectively arranged on both sides of the first cutting edge 22. During the milling process, the second cutting edge 23 cuts most of the excess of the workpiece, and the remaining small part of the machining excess is fine-machined by the extrusion action of the first cutting edge 22, thereby ensuring the machining accuracy, improving the surface roughness of the machined surface, avoiding wear on the first cutting edge 22, and extending the service life of the first cutting edge 22.

[0044] In addition, in this embodiment, since the first chip groove 24 defined between the first cutting edge 22 and the second cutting edge 23 gradually increases in width from the top area of ​​the cutting body 21 to both ends, it can ensure that the waste chips in the top area of ​​the tool are discharged in time, thereby avoiding the adverse effects of waste chips accumulated in the top area of ​​the cutting body 21 on the processing effect and the life of the tool.

[0045] Preferably, in this embodiment, the first cutting edge 22 passes through the vertex of the cutting body 21, and the cutting body 21 is symmetrically distributed about the first cutting edge 22; during the milling process, the middle area of ​​the first cutting edge 22 is mainly used to extrude the workpiece with a small excess, thereby improving the surface roughness and contour of the processed workpiece.

[0046] Specifically, in this embodiment, each of the second cutting edges 23 is symmetrically distributed with respect to the first cutting edge 22, which can ensure the stability of the tool when it rotates and avoid the tool chattering phenomenon during the machining process.

[0047] As an alternative to the above technical solution, the first cutting edge 22 may also be arranged to deviate from the vertex of the cutting body 21 , that is, the first cutting edge 22 may be arranged to deviate from the symmetry center line of the cutting body 21 .

[0048] Continue to refer to the attached Figure 2 As shown, the second cutting edge 23 is in an arc shape protruding toward the first cutting edge 22, so that the width of the first chip groove 24 gradually increases from the middle to the two ends.

[0049] Specifically, the second cutting edge 23 includes a first cutting segment 231 and a second cutting segment 232, wherein the first cutting segment 231 extends from one side of the cutting body 21 to the top region thereof and then is connected to one end of the second cutting segment 232, and the second cutting segment 232 extends from the top region of the cutting body 21 to the other side of the cutting body 21;

[0050] The first cutting segment 231 and the second cutting segment 232 are both spiral-shaped, and the rotation direction of the first cutting segment 231 is opposite to that of the second cutting segment 232 .

[0051] In the present technical solution, the first cutting segment 231 and the second cutting segment 232 of opposite rotation directions are connected to form an arc shape protruding toward the first cutting edge 22, so that most of the excess of the workpiece can be cut and the contour of the processed surface can be guaranteed.

[0052] In this embodiment, the helix angles of the first cutting segment 231 and the second cutting segment 232 are both 0-80°. Based on the helix angles, the strength, sharpness, and cutting force of the second cutting edge 23 are ideal, and the chip removal speed can be guaranteed.

[0053] like Figure 2 As shown, the diameter of the cutting body 21 is D, D = 0.2㎜ ~ 20㎜, and the specific size is determined according to the size of the processed curved surface; the distance between the two side surfaces of the cutting edge is defined as the blade width, the blade width of the first cutting edge 22 is L1, and the blade width of the second cutting edge 23 is L2, wherein L1 and L2 are both 0.005㎜ ~ 0.2㎜; in addition, the groove depth of the first chip groove 24 is set to 0.05㎜ ~ 1㎜ to ensure the smooth discharge of waste chips during milling.

[0054] Similarly, in order to further increase the cutting force and processing accuracy, and improve the chip removal ability, the outer surface of the cutting body 21 is also provided with a plurality of third cutting edges 251, and each of the third cutting edges 251 is respectively arranged on the outer side of the two second cutting edges 23 located at the outermost sides, and a second chip groove 26 is defined between two adjacent third cutting edges 251, and between the third cutting edge 251 and the second cutting edge 23 adjacent thereto; during the milling process, the third cutting edge 251 and the second cutting edge 23 act simultaneously to cut most of the excess of the workpiece, and then cooperate with the first cutting edge 22 for fine machining.

[0055] In this embodiment, since the third cutting edge 251 is provided on the cutting body 21, it is possible to avoid line marks during processing, ensure the finishing depth, and achieve the effect of layered cutting.

[0056] Preferably, in this embodiment, the third cutting edges 251 are symmetrically distributed with respect to the first cutting edge 22, which can ensure the stability of the tool during rotation and prevent the tool from chattering during milling.

[0057] In this embodiment, each of the third cutting edges 251 is spiral-shaped, and the spiral arrangement can ensure a sufficiently large cutting force, thereby improving processing efficiency.

[0058] For the convenience of description, the third cutting edges 251 located on the same side of the first cutting edge 22 are defined as a cutting edge group 25. Figure 2 As shown, a cutting edge group 25 is respectively provided on the upper and lower sides of the first cutting edge 22; the cutting edge group 25 is a symmetrical structure, and the third cutting edges 251 located on one side of the symmetry center line of the cutting edge group 25 and the third cutting edges 251 located on the other side of the symmetry center line of the cutting edge group 25 have opposite rotation directions, which can further improve the cutting accuracy and improve the wear resistance of the tool to extend the service life of the tool.

[0059] For the same purpose, in this embodiment, the helix angle of the third cutting edge 251 is 0 to 80°, and the helix angle of each third cutting edge 251 in the cutting edge group 25 gradually decreases from both sides to the middle, which can further improve the wear resistance of the tool and ensure processing accuracy.

[0060] In order to ensure the strength of the tool, the third cutting edge 251 is connected to the second cutting edge 23 ; specifically, one end of the third cutting edge 251 is connected to the second cutting edge 23 , and the other end of the third cutting edge 251 is disposed on the outer surface of the cutting body 21 .

[0061] As an alternative to the above technical solution, the third cutting edge 251 can be extended to the outer side surface of the connecting portion 1, thereby increasing the processing range of the tool; illustratively, both ends of the first cutting edge 22 and the second cutting edge 23 also extend to the outer side surface of the connecting portion 1.

[0062] Illustratively, in this embodiment, six third cutting edges 251 are respectively provided on both sides of the first cutting edge 22; the number of the third cutting edges 251 may be appropriately increased to improve the machining accuracy.

[0063] In this embodiment, the outer surface of the cutting body 21 is a hemispherical surface, and the connecting portion 1 is a cylindrical structure having the same diameter as the cutting body 21 .

[0064] In this embodiment, the cutting body 21, the first cutting edge 22, the second cutting edge 23 and the third cutting edge 251 are integrally formed, which not only facilitates the molding of each cutting edge on the outer surface of the cutting body 21, but also ensures the overall wear resistance and overall strength of the cutting edge portion 2.

[0065] In this embodiment, the material of the cutting edge portion 2 is preferably polycrystalline diamond. Compared with traditional coated milling cutters, the wear resistance of the tool with an integral polycrystalline diamond structure is greatly improved, which effectively improves the processing accuracy and processing efficiency and can extend the service life of the tool.

[0066] Similarly, the material of the cutting edge portion 2 may also be set to single crystal diamond, chemical vapor deposited diamond, polycrystalline cubic boron nitride, ceramics, cemented carbide or others, which can also ensure the wear resistance of the tool.

[0067] The cutting edge portion 2 and the connecting portion 1 are made of the same material, and the cutting edge portion 2 and the connecting portion 1 are integrally formed, which can ensure the strength of the entire tool head structure 100 .

[0068] Embodiment 2

[0069] This embodiment also provides a cutter head structure 100, specifically Figure 4 As shown, the only difference from the first embodiment is that six second cutting edges are arranged on the cutting body 21 in this embodiment, three second cutting edges are arranged on both sides of the first cutting edge 22, and a third chip groove 27 is defined between two adjacent second cutting edges.

[0070] Similarly, two, four or more second cutting edges 23 may be respectively disposed on both sides of the first cutting edge 22 , and the second cutting edges 23 may be arranged at intervals.

[0071] The second aspect of the present invention also provides a cutting tool, see the attached Figure 5 As shown, it includes a tool shank 200 and a tool head structure 100 as described in any embodiment of the first aspect, and the rear end face of the connecting portion 1 is connected to the front end face of the tool shank 200 .

[0072] The cutting tool in the embodiment of the present invention comprises the tool head structure 100 of any embodiment of the first aspect, and therefore has all the beneficial effects of the tool head structure 100, which will not be elaborated herein.

[0073] In addition, it should be noted that the cutting tool in the embodiment of the present invention is mainly used for processing graphite molds; when the cutting tool is rotated, the second cutting edge 23 and the third cutting edge 251 can remove most of the excess in the workpiece during the rotation and feeding process, and the remaining processing allowance of about 0.01 mm is squeezed and processed by the first cutting edge 22, which has the nature of rough processing first and then fine processing, and the waste chips generated during the milling process are discharged outward through the first chip groove 24 and the second chip groove 26 respectively.

[0074] When the cutting tool in this embodiment is used to process the graphite mold, the tool can continuously process 5 or more graphite molds, while the traditional tungsten steel coated ball cutter can usually only process 1 to 2 graphite molds; and the surface roughness of each processed graphite mold is highly stable and can reach below 500nm.

[0075] In summary, an embodiment of the present invention provides a cutting tool and a cutting head structure thereof, which can improve the surface roughness of the workpiece and extend the service life of the first cutting edge by arranging a first cutting edge and a plurality of second cutting edges located on both sides of the first cutting edge on the cutting body, and by coordinating the cutting action of the second cutting edge and the extrusion action of the first cutting edge; and the first chip groove defined between the first cutting edge and the second cutting edge gradually widens from the middle area to the two ends, which can ensure the chip removal performance and prevent waste chips from accumulating in the top area of ​​the cutting body during milling, so as to avoid adverse effects on the machining accuracy.

[0076] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention. These improvements and substitutions should also be regarded as the scope of protection of the present invention.

Claims

1. A cutter head structure, characterized in that: The cutting edge portion includes a cutting body, the outer surface of the cutting body is a forward convex arc surface, and the outer surface of the cutting body is provided with a first cutting edge and at least two second cutting edges. The first cutting edge extends from one side of the cutting body to the top area thereof, and then extends to the other side of the cutting body, each of the second cutting edges is respectively arranged on both sides of the first cutting edge, a first chip removal groove is defined between the first cutting edge and the second cutting edge adjacent thereto, and the width of the first chip removal groove gradually increases from the top area of ​​the cutting body to both ends; When viewed from the front of the cutting edge portion, the first cutting edge is a straight line. The first cutting edge passes through the vertex of the cutting body, and the cutting body is symmetrical about the first cutting edge, Each of the second cutting edges is symmetrical with respect to the first cutting edge; The second cutting edge is in an arc shape convex toward the first cutting edge; The second cutting edge includes a first cutting segment and a second cutting segment, wherein the first cutting segment extends from one side of the cutting body to the top region thereof and then is connected to one end of the second cutting segment, and the second cutting segment extends from the top region of the cutting body to the other side of the cutting body; The first cutting segment and the second cutting segment are both spiral-shaped, and the rotation direction of the first cutting segment is opposite to that of the second cutting segment.

2. The cutter head structure according to claim 1, characterized in that: The helix angles of the first cutting segment and the second cutting segment are both 0-80°.

3. The cutter head structure according to claim 1, characterized in that: The second cutting edge is respectively arranged on both sides of the first cutting edge.

4. The cutter head structure according to claim 1, characterized in that: The diameter of the cutting body is 0.2 mm to 20 mm, the widths of the first cutting edge and the second cutting edge are 0.005 mm to 0.2 mm, and the depth of the first chip groove is 0.05 mm to 1 mm.

5. The cutter head structure according to claim 1, characterized in that: The cutting body, the first cutting edge and the second cutting edge are integrally formed.

6. The cutter head structure according to any one of claims 1 to 5, characterized in that: The outer surface of the cutting body is also provided with a plurality of third cutting edges, each of which is arranged on the outer side of the two second cutting edges located at the outermost sides, and a second chip groove is defined between two adjacent third cutting edges and between the third cutting edge and the second cutting edge adjacent thereto.

7. The cutter head structure according to claim 6, characterized in that: The third cutting edges are symmetrically distributed with respect to the first cutting edge.

8. The cutter head structure according to claim 6, characterized in that: Each of the third cutting edges is spiral-shaped.

9. The cutter head structure according to claim 8, characterized in that: The third cutting edges located on the same side of the first cutting edge form a cutting edge group, the cutting edge group is a symmetrical structure, and the third cutting edges located on one side of the symmetry center line of the cutting edge group have opposite rotation directions to the third cutting edges located on the other side of the symmetry center line of the cutting edge group.

10. The cutter head structure according to claim 9, characterized in that: The helix angle of the third cutting edge is 0-80°, and the helix angle of each third cutting edge in the cutting edge group gradually decreases from both sides to the middle.

11. The cutter head structure according to claim 6, characterized in that: One end of the third cutting edge is connected to the second cutting edge, and the other end of the third cutting edge is arranged on the outer surface of the cutting body.

12. The cutter head structure according to claim 1, characterized in that: The outer surface of the cutting body is hemispherical.

13. The cutter head structure according to claim 1, characterized in that: The material of the cutting edge portion is any one of polycrystalline diamond, single crystal diamond, chemical vapor deposition diamond, polycrystalline cubic boron nitride, ceramic and cemented carbide.

14. The cutter head structure according to claim 1, characterized in that: It also includes a connecting portion, and the rear end surface of the cutting body is connected to the front end of the connecting portion.

15. The cutter head structure according to claim 14, characterized in that: The cutting edge portion and the connecting portion are made of the same material, and the cutting edge portion and the connecting portion are integrally formed.

16. A cutting tool, characterized in that: It comprises a tool shank and a tool head structure as claimed in any one of claims 1 to 15, wherein the rear end face of the cutting body is connected to the front end of the tool shank.

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