Round nose end mill

Abstract

This invention relates to the technical field of metal cutting tools, specifically to a round nose end mill, comprising a neck and a cutting edge. One end of the cutting edge is connected to the neck, and the other end has a plurality of end edges arranged circumferentially around the axis of the neck. Each end edge extends from the edge of the cutting edge towards its center. A tip, including an A tip and a B tip, is located near the center of the cutting edge. Adjacent end edges each have an A tip and a B tip, and the distances from the A tip and the B tip to the axis of the neck are not equal. During the rotational cutting process, the A tip and the B tip, along with the high-speed rotation of the neck, jointly form a cutting surface with two cutting angles, thereby reducing the adhesion between the chips and the cutting edge, reducing heat generation, and effectively preventing premature tool failure due to heat concentration.

Description

Technical Field

[0001] This invention relates to the technical field of metal cutting tools, and more specifically to a round nose end mill. Background Technology

[0002] The cutting edge of a milling cutter is usually set with a single radius. Due to this design, chips tend to stick to the cutting edge during metal cutting, which increases the friction between the tool and the workpiece. The large amount of heat generated by friction is concentrated on the cutting edge, causing the tool to wear easily. In addition, the single radius design also makes the cutting edge subject to greater force during actual cutting, and in severe cases, it may even cause chipping. Summary of the Invention

[0003] This invention aims to at least solve one of the technical problems existing in the prior art. To this end, this invention proposes a round nose end mill that can reduce frictional heat between the tool and the workpiece, thereby helping to extend the tool's service life.

[0004] According to an embodiment of the present invention, a round nose end mill includes a neck and a cutting edge. The cutting edge includes an end edge, a side edge, and a tip. One end of the cutting edge is connected to the neck, and the end face of the other end is provided with a plurality of end edges arranged circumferentially around the axis of the neck. The circumferential surface of the cutting edge is provided with a side edge corresponding to the end edge, and the side edge is connected to the corresponding end edge to form a tip. The tip includes tip A and tip B. Two adjacent end edges are respectively provided with tip A and tip B, and the distances of tip A and tip B from the axis of the neck are not equal.

[0005] The round nose end mill according to embodiments of the present invention has at least the following beneficial effects:

[0006] In this embodiment of the invention, an end cutting edge, a side cutting edge, and a cutting tip are provided on the end face of the milling cutter to perform planar milling or right-angle milling. The A cutting tip and the B cutting tip are not set in the same way. Therefore, the A cutting tip and the B cutting tip will form different cutting angles. During the rotation and cutting process of the milling cutter, the A cutting tip and the B cutting tip will jointly form a cutting surface with two cutting angles as the cutter neck rotates at high speed. The notch between the two cutting angles can further cut the chips, thereby reducing the adhesion between the chips and the cutting edge, reducing the friction between the tool and the workpiece, and thus reducing the generation of heat. This can effectively prevent the tool from failing prematurely due to heat concentration.

[0007] According to some embodiments of the present invention, the A-tip is provided with a rounded transition, and the B-tip is provided with a transition combining rounded and straight lines.

[0008] According to some embodiments of the present invention, there is a height difference between blade tip A and blade tip B in the axial direction of the blade neck, the height difference being 0.05-0.15mm.

[0009] According to some embodiments of the present invention, the number of end blades is 8, of which 4 end blades are provided with A-tip at the end and the remaining 4 end blades are provided with B-tip at the end.

[0010] According to some embodiments of the present invention, the side blades are spirally arranged along the axis of the blade neck, a spiral chip removal groove is formed between two adjacent side blades, a chip breaking groove is provided on the side blades and communicates with the chip removal groove, and a chip receiving groove is provided between two adjacent end blades and communicates with the chip removal groove.

[0011] According to some embodiments of the present invention, the side cutting edge includes A side cutting edge and B side cutting edge arranged at intervals, and two adjacent end cutting edges are respectively connected to A side cutting edge and B side cutting edge, and A side cutting edge is provided with chip breaking groove.

[0012] According to some embodiments of the present invention, the helix angle of the side blade is 20-30°, the front face of the side blade is provided with a side blade front angle, and the rear face of the side blade is provided with a side blade back angle A and a side blade back angle B, the side blade back angle A is 6-13°, and the side blade back angle B is 15-25°.

[0013] According to some embodiments of the present invention, the angle of the rake angle of the side blade within 1 mm of the end face of the blade is -5° to 3°, and the angle of the rake angle of the side blade beyond 1 mm of the end face of the blade is 3-8°.

[0014] According to some embodiments of the present invention, the front face of the end blade is provided with an end blade rake angle of 0-5°, and the rear face of the end blade is provided with an end blade first rear angle and an end blade second rear angle of 5-10° and an end blade second rear angle of 12-25°.

[0015] According to some embodiments of the present invention, the surface of the blade is provided with a wear-resistant coating.

[0016] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0018] Figure 1 This is a schematic diagram of the structure of a round nose end mill according to an embodiment of the present invention;

[0019] Figure 2 This is a schematic diagram of the A-tip of a round nose end mill according to an embodiment of the present invention;

[0020] Figure 3 This is a schematic diagram of the B-tip of a round nose end mill according to an embodiment of the present invention;

[0021] Figure 4This is a schematic diagram of the cutting surface of the tool tip during the cutting process according to an embodiment of the present invention;

[0022] Figure 5 This is a schematic diagram of the end face of a round nose end mill in an embodiment of the present invention, at a point within 1 mm from the end face of the cutting edge.

[0023] Figure 6 This is a schematic diagram of the end face of a round nose end mill according to an embodiment of the present invention, located at a point more than 1 mm away from the end face of the cutting edge.

[0024] Figure 7 This is a schematic diagram of the end-cutting parameters of a round nose end mill according to an embodiment of the present invention.

[0025] Figure label:

[0026] Neck 100; Cutting edge 200; End edge 210; End edge rake angle 211; End edge first clearance angle 212; End edge second clearance angle 213; Cutting tip 220; A-tip 221; A-tip cutting angle 221a; B-tip 222; B-tip cutting angle 222a; Notch 223; Side edge 230; A-side edge 231; B-side edge 232; Side edge first clearance angle 233; Side edge second clearance angle 234; Side edge rake angle 235; Chip removal groove 240; Chip breaking groove 250; Chip receiving groove 260. Detailed Implementation

[0027] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0028] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0029] In the description of this invention, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0030] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0031] In the description of this invention, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the invention. 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.

[0032] Please see Figure 1 According to some embodiments of the present invention, a round nose end mill includes a neck 100 and a cutting edge 200, wherein the cutting edge includes an end cutting edge 210, a side cutting edge 230, and a cutting tip 220. Specifically, the neck 100 is a cylinder, and the cutting edge 200 is disposed at one end of the neck 100 along the same axis. The cutting edge 200 and the neck 100 are integrally formed to optimize the manufacturing process of the round nose end mill. The end face of the other end of the cutting edge 200 is provided with a plurality of end cutting edges 210, which are arranged circumferentially around the axis of the neck 100. Each end cutting edge 210 extends from the edge of the cutting edge 200 toward the center of the cutting edge 200. The circumferential surface of the cutting edge 200 is provided with a side cutting edge 230 corresponding to the end cutting edge 210. The side cutting edge 230 is connected to the corresponding end cutting edge 210 to form the cutting tip 220.

[0033] The blade tip 220 includes a blade tip A 221 and a blade tip B 222. Two adjacent end blades 210 are respectively provided with blade tip A 221 and blade tip B 222. Specifically, there are 8 end blades 210, of which 4 end blades 210 are provided with blade tip A 221 at their ends, and the remaining 4 end blades 210 are provided with blade tip B 222 at their ends. Blade tips A 221 and blade tips B 222 are arranged at intervals around the axis of the blade neck 100.

[0034] The distances from the blade tip 221 (A) and blade tip 222 (B) to the axis of the blade neck 100 are not equal. Please refer to [link / reference]. Figure 4According to this configuration, cutting tips A and B form cutting angles 221a and 222a respectively on the workpiece. During the rotational cutting process of the milling cutter, cutting tips A and B together form a cutting surface with two cutting angles as the neck of the cutter 100 rotates at high speed. Compared with conventional round nose milling cutters with a single cutting radius, this embodiment of the invention can distribute the cutting force generated during the cutting process on cutting tips A and B, reducing the concentrated distribution of cutting force and lowering the risk of chipping. In addition, the notch 223 between cutting angles A and B can further cut the chips on the workpiece, making the chips shorter, thereby reducing the adhesion of chips to the end edge 210 and the cutting tip 220, which reduces the friction between the workpiece and the tool and prevents the cutting edge from failing due to excessive heat.

[0035] Please see Figure 2 and Figure 3 The A-tip 221 can be set with a rounded transition, and the B-tip 222 can be set with a combination of rounded and straight transitions. If the A-tip 221 and the B-tip 222 are overlapped for comparison, their tops should be staggered. Therefore, the two adjacent tips 220 can combine to form a cutting surface with double cutting edges in the actual cutting process. Since both the A-tip 221 and the B-tip 222 adopt a smooth transition such as rounded arcs in this embodiment, the two cutting edges combine to form a cutting surface with double rounded cutting angles, which can further reduce the frictional heat generated when the cutting edges contact the workpiece.

[0036] Furthermore, along the axial direction of the blade neck 100, the A-tip 221 and B-tip 222 form a height difference, which can be understood as the axial distance between them, and the height difference is 0.05-0.15mm. This arrangement allows the chips to be effectively cut by the A-tip 221, B-tip 222, and notch 223, reducing the adhesion between the chips and the end cutting edge 210.

[0037] Please continue reading. Figure 1 The side cutting edge 230 is spirally arranged along the axis of the neck 100, and a spiral chip removal groove 240 is formed between two adjacent side cutting edges 230. The spiral angle between the side cutting edge 230 and the chip removal groove 240 is 20-30°. The side cutting edge 230 is provided with a chip breaking groove 250 that communicates with the chip removal groove 240. The purpose of setting the chip breaking groove 250 is to cut the chips, so that the chips in the chip removal groove 240 can flow out, preventing the chips from accumulating in the chip removal groove 240 and causing friction on the workpiece surface, which helps to ensure the surface finish of the product after roughing.

[0038] It should be further explained that the side cutting edge 230 includes side cutting edge A 231 and side cutting edge B 232. Two adjacent end cutting edges 210 are respectively connected to side cutting edge A 231 and side cutting edge B 232, thus side cutting edge A 231 and side cutting edge B 232 are arranged alternately. Side cutting edge A 231 is provided with chip breaking groove 250. Compared with the practice of providing chip breaking groove 250 on all side cutting edges 230, providing chip breaking groove 250 on the spaced A side cutting edges 231 helps to maintain the overall strength of the side cutting edge 230.

[0039] In addition, in order to ensure the rigidity of the chip breaker groove 250 and avoid chipping during roughing, the edge of the chip breaker groove 250 is rounded with a radius of 0.2-0.5mm.

[0040] Furthermore, a chip groove 260 is provided between two adjacent end cutting edges 210. The chip groove 260 is connected to the chip removal groove 240. The chips generated during roughing are discharged outward through the chip groove 260 into the chip removal groove 240, thereby preventing chips from accumulating on the end face of the cutting edge 200 and affecting the efficiency and effect of milling.

[0041] Please see Figure 5 and Figure 6 In order to achieve better heat dissipation during roughing, the back angle of the side cutting edge 230 is set as a double-plane back angle. Specifically, the back face of the side cutting edge 230 is provided with a first back angle 233 and a second back angle 234. The first back angle 233 is 6-13° and the second back angle 234 is 15-25°. With this setting, some of the heat generated by the tool during cutting can be dissipated outward through the first back angle 233, thereby reducing the heat transferred to the main body of the side cutting edge 230.

[0042] The rake face of the side cutting edge 230 has a rake angle 235. The rake angle 235 needs to have sufficient roughing tool strength and provide sufficient cutting force. For this reason, such as... Figure 5 As shown, in this embodiment of the application, the rake angle 235 of the side blade within 1mm of the end face of the blade portion 200 is set to -5° to 3°. Figure 6 As shown, the rake angle 235 of the side cutting edge, located more than 1 mm from the end face of the cutting edge 200, is set to 3-8°. The reason for setting two different rake angles 235 is that the side cutting edge 230 closer to the end face of the cutting edge 200 needs to provide a larger cutting force during the cutting process, so the rake angle 235 here should be set smaller to improve sharpness; for the side cutting edge 230 farther from the end face of the cutting edge 200, if the rake angle is too small, it will lead to an increase in cutting force, and the tool is prone to generate obvious vibration on the cutting surface of the workpiece, which will have an adverse effect on the performance of the side cutting edge 230 and the surface quality of the workpiece.

[0043] Please see Figure 7The rake face of the end cutting edge 210 is provided with an end cutting rake angle 211, which is 0-5°. This ensures the sharpness of the cutting edge 200 in cutting the workpiece and improves the chipping resistance of the cutting edge 200, thereby increasing the overall service life of the round nose end mill. The flank face of the end cutting edge 210 is provided with a first flank angle 210b and a second flank angle 213, which are 5-10° and 12-25° respectively. This angle setting reduces the friction on the cutting edge 200 during depth cutting and improves chip removal performance during cutting.

[0044] In addition, the surface of the cutting edge 200 is provided with a wear-resistant coating, such as a TiB2 coating. The boron-based coating can effectively prevent tool edge wear caused by element diffusion, thereby improving the wear resistance of the cutting edge 200 and extending the service life of the round nose end mill.

[0045] In summary, the embodiments of this application optimize the cutting structure of the tool, setting a cutting surface with two types of arc tips, thereby significantly improving the roughing performance of the round nose end mill, protecting the surface quality of the workpiece during roughing, and setting a wear-resistant coating on the cutting edge surface to improve the tool's wear resistance.

[0046] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments, and various changes can be made within the scope of knowledge possessed by those skilled in the art without departing from the spirit of the present invention. Furthermore, the embodiments of the present invention and the features thereof can be combined with each other unless otherwise specified.

Claims

1. A round nose end mill, characterized in that, include: Neck of the knife; The blade portion includes an end blade, a side blade, and a blade tip. One end of the blade portion is connected to the neck of the blade, and the end face of the other end is provided with a plurality of end blades. The end blades are arranged circumferentially around the axis of the neck of the blade. The circumferential surface of the blade portion is provided with a side blade corresponding to the end blade. The side blade is connected to the corresponding end blade to form the blade tip. The blade tip includes a blade tip A and a blade tip B. Two adjacent end edges are respectively provided with blade tip A and blade tip B, and the distances from blade tip A and blade tip B to the axis of the blade neck are not equal. The A-tip is designed with a rounded transition, while the B-tip is designed with a combination of rounded and straight transitions. There is a height difference between the A-tip and the B-tip along the axial direction of the blade neck.

2. The round nose end mill according to claim 1, characterized in that, The height difference is 0.05-0.15mm.

3. The round nose end mill according to claim 2, characterized in that, The number of the end blades (210) is 8, of which 4 end blades are provided with the A blade tip and the remaining 4 end blades are provided with the B blade tip.

4. The round nose end mill according to claim 1, characterized in that, The side blades are spirally arranged along the axis of the blade neck, and a spiral chip removal groove is formed between two adjacent side blades. The side blades are provided with chip breaking grooves that communicate with the chip removal grooves. Chip receiving grooves are provided between two adjacent end blades and at the center of all blade portions. The chip receiving grooves communicate with the chip removal grooves.

5. The round nose end mill according to claim 4, characterized in that, The side cutting edge includes A side cutting edge and B side cutting edge arranged at intervals. Two adjacent end cutting edges are respectively connected to A side cutting edge and B side cutting edge. The chip breaking groove is provided on A side cutting edge.

6. The round nose end mill according to claim 4, characterized in that, The helix angle of the side blade is 20-30°. The front face of the side blade is provided with a front angle. The rear face of the side blade is provided with a first rear angle and a second rear angle. The first rear angle is 6-13° and the second rear angle is 15-25°.

7. The round nose end mill according to claim 6, characterized in that, The angle of the rake angle of the side blade within 1 mm of the end face of the blade is -5° to 3°, and the angle of the rake angle of the side blade beyond 1 mm of the end face of the blade is 3-8°.

8. The round nose end mill according to claim 1, characterized in that, The front face of the end blade is provided with a front angle of 0-5°. The rear face of the end blade is provided with a first rear angle and a second rear angle of 5-10° and a second rear angle of 12-25°.

9. The round nose end mill according to claim 1, characterized in that, The surface of the blade is coated with a wear-resistant coating.

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