CBN (cubic boron nitride) ball-end cutter

Abstract

A cubic boron nitride (CBN) ball-end cutter comprises a cutter bar and a cutter head made of cubic boron nitride materials, the cutter head comprises a welding area and a ball-end cutting portion participating in cutting, the cutter bar is provided with a cutter neck portion playing a connecting and supporting role, and the welding area is welded to the cutter neck portion in a vacuum welding mode. Wherein the ball head cutting part comprises a ball head cutting edge, first rear angle surfaces and second rear angle surfaces, the projection of the ball head cutting edge towards the direction of the cutter neck part coincides with the center line of the cutter neck part, the first rear angle surfaces are formed on the two sides of the ball head cutting edge, and the second rear angle surfaces are formed on the two sides of the ball head cutting edge. The second rear angle face is connected to the side, away from the ball head cutting edge, of the first rear angle face.

Description

Technical Field

[0001] This utility model relates to the field of cutting tool technology, and in particular to a CBN ball end mill. Background Technology

[0002] Ball end mills are cutting tools used in mechanical manufacturing, primarily for machining planes, steps, grooves, shaped surfaces, and cutting workpieces. Most ball end mills have a carbide coating on their surface to improve wear resistance and service life. However, when machining mold surfaces with carbide-coated ball end mills, the cutting speed is limited due to the inherent strength of the material, resulting in low machining efficiency and failing to meet machining requirements. Utility Model Content

[0003] This utility model provides a CBN ball end mill, which aims to solve at least one of the technical problems existing in the prior art.

[0004] This utility model provides a CBN ball end mill, including a shank and a cutting head made of cubic boron nitride material. The cutting head includes a welding area and a ball end cutting part that participates in cutting. The shank has a neck that serves as a connecting support. The welding area is welded to the neck by vacuum welding.

[0005] The ball-end cutting portion includes a ball-end cutting edge, a first rear facet, and a second rear facet. The projection of the ball-end cutting edge toward the neck of the cutter coincides with the centerline of the neck of the cutter. The first rear facet is formed on both sides of the ball-end cutting edge, and the second rear facet is connected to the side of the first rear facet away from the ball-end cutting edge.

[0006] In a CBN ball end mill according to one embodiment of the present invention, the ratio of the radius of the ball end cutting edge to the maximum radius of the tool shank is greater than or equal to 0.16 and less than or equal to 0.6.

[0007] In a CBN ball end mill according to one embodiment of the present invention, the ratio of the radius of the ball end cutting edge to the height of the neck of the cutter is greater than or equal to 0.16 and less than or equal to 0.6.

[0008] In a CBN ball end mill according to one embodiment of the present invention, the ratio of the radius of the ball end cutting edge to the maximum radius of the neck of the cutter is greater than or equal to 0.25 and less than or equal to 0.5.

[0009] In a CBN ball end mill according to one embodiment of the present invention, the ratio of the radius of the ball end cutting edge to the height of the ball end cutting edge is greater than or equal to 0.3 and less than or equal to 0.6.

[0010] In one embodiment of the CBN ball end mill of this utility model, the radius of the ball end cutting edge is greater than or equal to 0.5 mm and less than or equal to 1 mm.

[0011] In a CBN ball end mill according to one embodiment of the present invention, the included angle α between the first rear corner face and the vertical line perpendicular to the axial direction of the cutter head is greater than or equal to 25° and less than or equal to 30°.

[0012] In a CBN ball end mill according to one embodiment of the present invention, the included angle β between the second rear face and the vertical line perpendicular to the axial direction of the cutter head is greater than or equal to 40° and less than or equal to 45°.

[0013] In a CBN ball end mill according to one embodiment of the present invention, the ratio of the width of the ball end cutting edge to the radius of the ball end cutting edge is greater than or equal to 0.9 and less than or equal to 0.11.

[0014] In a CBN ball end mill according to one embodiment of the present invention, the end mill is made of cubic boron nitride material, and the shank is made of cemented carbide.

[0015] The technical solution provided in this application embodiment can include the following beneficial effects: This application designs a CBN ball end mill, including a tool shank and a tool head made of cubic boron nitride material. The tool head is welded to the neck of the tool shank by vacuum welding. Due to the hardness and chemical stability of cubic boron nitride material, it has better material properties, so that when the CBN ball end mill is used to machine mold surfaces, there is no need to limit the cutting speed, thereby improving machining efficiency and significantly extending the service life of the CBN ball end mill. The ball cutting part of the tool head includes a ball cutting edge, a first clearance angle surface, and a second clearance angle surface. The projection of the ball cutting edge toward the neck of the tool head coincides with the center line of the neck of the tool head, which can effectively reduce the cutting resistance of the CBN ball end mill at the center position, extend tool life, and improve machining accuracy.

[0016] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the structure of a CBN ball end mill provided in an embodiment of this application at a first angle;

[0019] Figure 2 yes Figure 1 A schematic diagram of the CBN ball end mill at the second angle;

[0020] Figure 3 yes Figure 1 A schematic diagram of the CBN ball end mill at the third angle;

[0021] Figure 4 yes Figure 1 An exploded view of the CBN ball end mill in the image;

[0022] Figure 5 yes Figure 4 A schematic diagram of the cutter head at the first angle;

[0023] Figure 6 yes Figure 4 A schematic diagram of the cutter head at the second angle.

[0024] Explanation of reference numerals in the attached figures:

[0025] 10. Cutting head; 10a. Ball end cutting section; 11. Ball end cutting edge; 12. First clearance angle face; 13. Second clearance angle face; 10b. Welding area;

[0026] 20. Blade shank; 21. Main body; 22. Blade neck. Detailed Implementation

[0027] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0028] It should also be understood that the terminology used in this utility model specification is merely for describing specific aspects of the present application. It is important to understand that terms such as "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," 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 present application 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 the present application. 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 indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0029] The following detailed description of some embodiments of this application is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0030] like Figures 1 to 6 As shown, this application provides a CBN ball end mill, including a tool shank 20 and a tool head 10 made of cubic boron nitride (CBN). The tool head 10 is welded to the tool shank 20 by vacuum welding, ensuring a strong bond between the tool head 10 and the tool shank 20 and avoiding loosening or detachment that may occur during high-speed cutting. The tool head 10 is made of cubic boron nitride (CBN), giving it high hardness and wear resistance. Compared to ball end mills with carbide coatings, which require cutting speeds limited to below 80 m / min due to the inherent strength of the carbide coating, the ball end mill of this application, made of cubic boron nitride (CBN), possesses better material properties due to its hardness and chemical stability, allowing cutting speeds to be increased to over 200 m / min. This significantly improves machining efficiency and is suitable for the high-efficiency, high-precision machining requirements of modern manufacturing.

[0031] It should be noted that vacuum welding is a high-precision welding method that can be performed in an oxygen-free environment, avoiding the effects of oxidation and impurities, and ensuring the high strength and stability of the welded area.

[0032] In an optional embodiment, the cutter head 10 includes a welding area 10b and a ball end mill 10a that participates in cutting. The cutter shank 20 has a main body 21 and a neck 22 that serves as a connection and support. The diameter of the neck 22 is smaller than the diameter of the main body 21. The welding area 10b is welded to the neck 22 by vacuum welding. The neck 22 not only reduces the weight of the cutter but also optimizes the stress distribution of the welding area 10b, ensuring the reliability of the welded connection. The main body 21 provides sufficient rigidity and stability for the ball end mill to support the forces acting on the entire cutter during the cutting process.

[0033] In an optional embodiment, the ball end mill 10a includes a ball end mill cutting edge 11, a first clearance angle surface 12, and a second clearance angle surface 13. The projection of the ball end mill cutting edge 11 toward the neck of the tool 22 coincides with the centerline of the neck of the tool 22 to ensure a symmetrical distribution of cutting force and avoid vibration and tool wear caused by eccentric cutting. The first clearance angle surface 12 is formed on both sides of the ball end mill cutting edge 11, reducing friction between the chips and the tool surface during cutting, thus reducing cutting heat and cutting resistance. The second clearance angle surface 13 is connected to the side of the first clearance angle surface 12 away from the ball end mill cutting edge 11, which can further expand the clearance angle range of the tool, reduce the contact area between the tool and the workpiece, effectively reduce the cutting resistance of the CBN ball end mill at the center position, extend tool life, and improve machining accuracy.

[0034] By adopting the above technical solutions, this application, through the rational design of the ball end cutting edge 11, the first clearance angle surface 12, and the second clearance angle surface 13, can not only effectively reduce the cutting resistance of the tool at the center position, especially during high-speed cutting, reducing tool wear and heat accumulation; but also, through the rational selection of the angles of the first clearance angle surface 12 and the second clearance angle surface 13, reduce the friction between the chips and the tool surface during cutting, reduce cutting resistance and cutting heat, improve cutting efficiency, and facilitate chip removal, avoiding the impact of chip accumulation on the surface quality of the machined part, thus meeting the needs of modern manufacturing for high-efficiency and high-stability machining.

[0035] In an optional embodiment, the ratio of the radius R of the ball end cutting edge 11 to the maximum radius D1 / 2 of the tool holder 20 is greater than or equal to 0.16 and less than or equal to 0.6, so that the ball end cutting edge 11 can maintain appropriate strength and flexibility during the cutting process, reduce cutting resistance, and improve cutting efficiency.

[0036] It should be noted that the radius R of the ball end cutting edge 11 is a key parameter of the cutting part of the tool, directly affecting the cutting force distribution, chip removal, and surface finish during the cutting process. A larger ball end radius R can provide stronger cutting edge strength, suitable for heavy cutting and high-load machining; a smaller ball end radius R is suitable for fine machining and high-precision machining of complex curved surfaces. The maximum radius D1 / 2 of the tool holder 20 is the radius of the main body 21 of the tool holder 20, determining the overall rigidity and stability of the tool. A larger tool holder radius D1 / 2 can provide higher rigidity, suitable for high-speed cutting and machining of high-hardness materials; a smaller tool holder radius D1 / 2 is suitable for machining in confined spaces. Therefore, the application limits the ratio of the radius R of the ball end cutting edge 11 to the maximum radius D1 / 2 of the tool holder 20 to the range of 0.16 to 0.6, achieving an optimal balance in cutting performance, stability, and applicability.

[0037] For example, when the ratio of the radius R of the ball end cutting edge 11 to the maximum radius D1 / 2 of the tool holder 20 is ≥0.16, it ensures that the ball end cutting edge 11 has sufficient strength, avoiding the problem of a fragile cutting edge due to an excessively small radius, while effectively dispersing cutting forces and reducing tool wear. When the ratio of the radius R of the ball end cutting edge 11 to the maximum radius D1 / 2 of the tool holder 20 is ≤0.6, it avoids the increase in cutting resistance and the reduction in tool flexibility caused by an excessively large ball end radius, ensuring that the tool can adapt to the machining requirements of complex curved surfaces. Therefore, by reasonably limiting the radius ratio range, this application enables the ball end cutting edge 11 to maintain appropriate strength and flexibility during cutting, reduce cutting resistance, improve cutting efficiency, ensure uniform distribution of cutting forces, reduce vibration and tool deformation, and improve machining stability; it also avoids stress concentration and accelerated wear caused by an excessively small radius, while avoiding the increase in cutting resistance caused by an excessively large radius, thereby extending the tool's service life.

[0038] In an optional embodiment, the ratio of the radius R of the ball-end cutting edge 11 to the height L2 of the neck 22 is greater than or equal to 0.16 and less than or equal to 0.6, achieving an optimal balance in cutting performance, stability, and applicability. The height L2 of the neck 22 is the portion of the tool holder 20 connecting the tool head 10 and the main body 21. Its height determines the overhang length of the tool head 10 and the overall rigidity of the tool. A higher neck 22L2 provides greater flexibility, suitable for machining complex curved surfaces; a lower neck 22L2 increases the rigidity of the tool, suitable for high-load cutting. This application limits the ratio of the radius R of the ball-end cutting edge 11 to the height of the neck 22L2 to the range of 0.16 to 0.6, enabling the ball-end cutting edge 11 to maintain appropriate strength and flexibility during cutting, reducing cutting resistance, and improving cutting efficiency.

[0039] For example, when the ratio of the radius R of the ball end cutting edge 11 to the height L2 of the neck 22 is ≥0.16, the ball end cutting edge 11 can be ensured to have sufficient strength, avoiding the problem of a fragile cutting edge due to an excessively small radius, while effectively dispersing cutting forces and reducing tool wear. When the ratio of the radius R of the ball end cutting edge 11 to the height L2 of the neck 22 is ≤0.6, the increased cutting resistance and reduced tool flexibility caused by an excessively large ball end radius can be avoided, ensuring that the tool can adapt to the machining requirements of complex curved surfaces. Therefore, this application, through a reasonable design of the neck 22 height, can ensure the rigidity of the tool during the cutting process, while the optimized design of the ball end radius can ensure the uniform distribution of cutting forces, reduce vibration and tool deformation, and improve machining stability.

[0040] In one optional embodiment, the ratio of the radius R of the ball-end cutting edge 11 to the maximum radius D2 of the neck 22 is greater than or equal to 0.25 and less than or equal to 0.5, achieving an optimal balance in cutting performance, stability, and applicability. This significantly improves the machining efficiency, service life, and accuracy of the tool, meeting the demands of modern manufacturing for high-efficiency and high-stability machining. The maximum radius D2 of the neck 22 is the radius of the portion of the tool holder 20 connecting the tool head 10 and the main body 21. Its size determines the rigidity and connection strength of the neck 22. A larger neck radius D2 provides higher rigidity, suitable for high-load cutting; a smaller neck radius D2 improves tool flexibility, suitable for machining complex curved surfaces. Therefore, this application limits the ratio of the radius of the ball-end cutting edge 11 to the maximum radius of the neck 22 to the range of 0.25 to 0.5, ensuring that the ball-end cutting edge 11 maintains appropriate strength and flexibility during cutting, reducing cutting resistance and improving cutting efficiency.

[0041] For example, when the ratio of the radius R of the ball end mill 11 to the maximum radius D2 of the neck 22 is ≥0.25, it ensures that the ball end mill 11 has sufficient strength, avoiding the problem of a fragile cutting edge due to an excessively small radius, while effectively dispersing cutting forces and reducing tool wear. When the ratio of the radius R of the ball end mill 11 to the maximum radius D2 of the neck 22 is ≤0.5, it avoids the increase in cutting resistance and the reduction in tool flexibility caused by an excessively large ball end radius, ensuring that the tool can adapt to the machining requirements of complex curved surfaces. Therefore, a reasonable design of the neck 22 radius ensures the rigidity of the tool during the cutting process, while the optimized design of the ball end radius ensures the uniform distribution of cutting forces, reduces vibration and tool deformation, improves machining stability, avoids stress concentration and accelerated wear caused by an excessively small radius, and avoids the increase in cutting resistance caused by an excessively large radius, thereby extending the tool's service life.

[0042] In one optional embodiment, the ratio of the radius R of the ball end cutting edge 11 to its height L1 is greater than or equal to 0.3 and less than or equal to 0.6. This achieves an optimal balance in cutting performance, stability, and applicability, significantly improving the tool's machining efficiency, service life, and accuracy, meeting the demands of modern manufacturing for high-efficiency and high-stability machining. The height of the ball end cutting edge 11 refers to the vertical distance from the bottom of the cutting head 10a to the top of the ball end. Its height determines the geometry and cutting performance of the cutting head 10a. A higher height provides a greater depth of cut, suitable for deep cavity machining; a lower height increases the tool's rigidity, suitable for high-precision machining. Therefore, this application limits the ratio of the radius of the ball end cutting edge 11 to its height to the range of 0.3 to 0.6, ensuring that the ball end cutting edge 11 maintains appropriate strength and flexibility during cutting, reducing cutting resistance and improving cutting efficiency.

[0043] For example, when the ratio of the radius R to the height L1 of the ball end cutting edge 11 is ≥0.3, it ensures that the ball end cutting edge 11 has sufficient strength, avoiding the problem of a fragile cutting edge due to an excessively small radius, while effectively dispersing cutting forces and reducing tool wear. When the ratio of the radius R to the height L1 of the ball end cutting edge 11 is ≤0.6, it avoids the increase in cutting resistance and the reduction in tool flexibility caused by an excessively large ball end radius, ensuring that the tool can adapt to the machining requirements of complex curved surfaces. Therefore, a reasonable height design of the ball end cutting edge 11 ensures the rigidity of the tool during the cutting process, while the optimized design of the ball end radius ensures the uniform distribution of cutting forces, reduces vibration and tool deformation, improves machining stability, and avoids stress concentration and accelerated wear caused by an excessively small radius, as well as increased cutting resistance caused by an excessively large radius, thereby extending the tool's service life.

[0044] In an optional embodiment, the radius R of the ball end cutting edge 11 is greater than or equal to 0.5 mm and less than or equal to 1 mm, so as to ensure the rigidity of the tool and the uniform distribution of cutting force during the cutting process, reduce vibration and tool deformation, and improve machining stability.

[0045] For example, when the radius R of the ball end cutting edge 11 is ≥ 0.5 mm, it ensures that the ball end cutting edge 11 has sufficient strength, avoiding the problem of a fragile cutting edge due to an excessively small radius, while effectively dispersing cutting forces and reducing tool wear. When the radius R of the ball end cutting edge 11 is ≤ 1 mm, it avoids the increase in cutting resistance and the reduction in tool flexibility caused by an excessively large ball end radius, ensuring that the tool can adapt to the machining requirements of complex curved surfaces. Therefore, this application reasonably limits the radius R range of the ball end cutting edge 11 so that the ball end cutting edge 11 can maintain appropriate strength and flexibility during cutting, reduce cutting resistance, and improve cutting efficiency. It also avoids stress concentration and accelerated wear caused by an excessively small radius, and increased cutting resistance caused by an excessively large radius, thereby extending the tool life.

[0046] In an optional embodiment, the angle α between the first clearance facet 12 and the vertical line perpendicular to the axis of the tool tip 10 is greater than or equal to 25° and less than or equal to 30°. This avoids increased chip friction and tool wear caused by an excessively small angle α, while also preventing a decrease in cutting edge strength caused by an excessively large angle α, thereby extending the tool's service life. The first clearance facet 12 is a key geometric feature of the tool's cutting portion, located on both sides of the ball end cutting edge 11. Its main function is to reduce friction between the chips and the tool surface during cutting, thereby reducing cutting heat and cutting resistance. Therefore, by rationally designing the angle of the first clearance facet 12, this application can optimize chip removal and avoid the impact of chip accumulation on the surface quality of the machined part.

[0047] For example, when α ≥ 25°, the first clearance face 12 can be ensured to have a sufficient clearance angle, reducing friction between the chip and the tool surface, lowering cutting heat and cutting resistance, and optimizing chip removal. When α ≤ 30°, the reduction in cutting edge strength caused by an excessively large clearance angle can be avoided, ensuring that the tool has sufficient strength and stability during high-load cutting. Therefore, by reasonably limiting the included angle range of the first clearance face 12, the tool can maintain an appropriate chip removal effect during cutting, reduce cutting resistance and cutting heat, improve cutting efficiency, ensure the rigidity of the tool during cutting, reduce vibration and tool deformation, and improve machining stability.

[0048] In an optional embodiment, the angle β between the second clearance face 13 and the vertical line perpendicular to the axis of the tool tip 10 is greater than or equal to 40° and less than or equal to 45°. This avoids increased chip friction and tool wear caused by an excessively small clearance angle, while also preventing a decrease in cutting edge strength caused by an excessively large clearance angle, thereby extending the tool's service life. The second clearance face 13 is a key geometric feature of the tool's cutting portion, connected to the side of the first clearance face 12 away from the ball end cutting edge 11. Its main function is to further reduce the contact area between the tool and the workpiece, reducing cutting resistance and cutting heat. Therefore, by rationally designing the angle of the second clearance face 13, the cutting performance of the tool can be optimized, especially in high-speed cutting and machining of high-hardness materials.

[0049] For example, when α ≥ 40°, the second clearance face 13 can be ensured to have a sufficient clearance angle, further reducing the contact area between the tool and the workpiece, lowering cutting resistance and cutting heat, while optimizing chip removal. When α ≤ 45°, the reduction in cutting edge strength caused by an excessively large clearance angle can be avoided, ensuring that the tool has sufficient strength and stability during high-load cutting. Therefore, by reasonably limiting the included angle range of the second clearance face 13, the tool can maintain an appropriate chip removal effect during cutting, reducing cutting resistance and cutting heat, and improving cutting efficiency; it also ensures the rigidity of the tool during cutting, reduces vibration and tool deformation, and improves machining stability.

[0050] In one optional embodiment, the ratio of the width W of the ball-end cutting edge 11 to its radius R is greater than or equal to 0.9 and less than or equal to 0.11. This avoids stress concentration and accelerated wear caused by an excessively small width, while also preventing increased cutting resistance caused by an excessively large width, thereby extending the tool's service life. The width of the ball-end cutting edge 11 is a key parameter of the tool's cutting portion, directly affecting the cutting force distribution, chip removal, and surface finish during the cutting process. A larger cutting edge width provides stronger cutting edge strength, suitable for heavy cutting and high-load machining; a smaller cutting edge width is suitable for fine machining and high-precision machining of complex curved surfaces. Therefore, this application limits the ratio of the width of the ball-end cutting edge 11 to its radius to the range of 0.9 to 1.1, enabling the ball-end cutting edge 11 to maintain appropriate strength and flexibility during cutting, reducing cutting resistance and improving cutting efficiency.

[0051] For example, when the ratio of the width W of the ball-end cutting edge 11 to its radius R is ≥0.9, it ensures that the ball-end cutting edge 11 has sufficient width, avoiding the problem of a fragile cutting edge due to excessive width, while effectively distributing cutting forces and reducing tool wear. When the ratio of the width W of the ball-end cutting edge 11 to its radius R is ≤1.1, it avoids the increase in cutting resistance and the reduction in tool flexibility caused by an excessively large cutting edge width, ensuring that the tool can adapt to the machining requirements of complex curved surfaces. Therefore, a reasonable cutting edge width design ensures the rigidity of the tool during the cutting process, while the optimized design of the ball end radius ensures the uniform distribution of cutting forces, reduces vibration and tool deformation, and improves machining stability.

[0052] In an optional embodiment, the tool holder 20 is made of cemented carbide, which can effectively reduce tool deformation during the cutting process, especially in high-speed cutting and high-load machining, ensuring machining accuracy and surface quality, and extending the service life of the CBN ball end mill.

[0053] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection. They can refer to a mechanical connection or an electrical connection. They can refer to a direct connection or an indirect connection through an intermediate medium, and they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0054] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0055] The foregoing disclosure provides many different embodiments or examples for implementing different structures of this application. To simplify the disclosure, specific examples of components and arrangements are described above. Of course, these are merely examples and are not intended to limit the scope of this application. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, examples of various specific processes and materials are provided in this application, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0056] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with an embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

Claims

1. A CBN ball end mill characterized by, The tool bar and the tool head made of cubic boron nitride material, the tool head includes a welding area and a ball head cutting part participating in cutting, the tool bar has a tool neck part playing a connecting support role, and the welding area is welded on the tool neck part by vacuum welding; The ball head cutting part includes a ball head cutting edge, a first clearance face, and a second clearance face, a projection of the ball head cutting edge toward the tool neck part direction coincides with a center line of the tool neck part, the first clearance face is formed on both sides of the ball head cutting edge, and the second clearance face is connected to one side of the first clearance face away from the ball head cutting edge.

2. The CBN ball end mill according to claim 1, wherein The ratio of the radius of the ball head cutting edge to the maximum radius of the tool bar is greater than or equal to 0.16 and less than or equal to 0.

6.

3. The CBN ball end mill of claim 1, wherein, The ratio of the radius of the ball head cutting edge to the height of the tool neck part is greater than or equal to 0.16 and less than or equal to 0.

6.

4. The CBN ball end mill of claim 1, wherein, The ratio of the radius of the ball head cutting edge to the maximum radius of the tool neck part is greater than or equal to 0.25 and less than or equal to 0.

5.

5. The CBN ball end mill of claim 1 wherein, The ratio of the radius of the ball head cutting edge to the height of the ball head cutting edge is greater than or equal to 0.3 and less than or equal to 0.

6.

6. The CBN ball end mill according to any one of claims 2 to 5, wherein, The radius of the ball head cutting edge is greater than or equal to 0.5 mm and less than or equal to 1 mm.

7. The CBN ball end mill of claim 1 wherein, The included angle α between the first clearance face and a vertical line perpendicular to the tool head in the axial direction is greater than or equal to 25° and less than or equal to 30°.

8. The CBN ball end mill of claim 1, wherein, The included angle β between the second clearance face and a vertical line perpendicular to the tool head in the axial direction is greater than or equal to 40° and less than or equal to 45°.

9. The CBN ball end mill of claim 1, wherein, The ratio of the width of the ball head cutting edge to the radius of the ball head cutting edge is greater than or equal to 0.9 and less than or equal to 0.

11.

10. The CBN ball end mill of claim 1 wherein, The tool bar is a tool bar made of cemented carbide.

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