roughing round nose milling cutter

Abstract

The present application relates to the technical field of metal cutting tools, and particularly relates to a roughing nose cutter, which comprises a shank part and a blade part, the blade part comprises an end blade, an A peripheral blade and a B peripheral blade, one end of the blade part is connected with the shank part, the end surface of the other end is provided with a plurality of end blades, the peripheral surface of the blade part is respectively provided with the A peripheral blade and the B peripheral blade, the A peripheral blade and the B peripheral blade are arranged at intervals around the axis of the shank part, and the A peripheral blade and the B peripheral blade are respectively arranged in a spiral along the axis direction of the shank part; the A peripheral blade is provided with a plurality of arc grooves in the spiral direction, and the arc grooves are used for chip breaking and flow containing during cutting; and the B peripheral blade is provided with a plurality of rough skin peripheral teeth arranged at intervals in the spiral direction. The method of arranging the arc grooves on the peripheral blade in the embodiment of the present application can change the chip breaking efficiency, flow containing frequency and period of the cuttings, realize the alternation of the chip breaking and flow containing, and optimize the chip breaking effect and flow containing effect.

Description

Technical Field

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

[0002] In the field of titanium alloy product processing, due to the characteristics of titanium alloy materials, cutting tools generally suffer from problems such as difficulty in timely heat dissipation of the cutting edge and strong metal affinity and diffusion of the cutting edge, which makes the cutting edge prone to chip adhesion, leading to edge wear or chipping. In severe cases, it can even cause problems such as tool burning, chipping, or even tool breakage. Such situations are particularly common in rough milling of titanium alloy materials, resulting in a generally low tool life and a significant increase in processing costs. 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 roughing round nose end mill that, through structural innovation, improves cutting edge cooling and chip breaking, and significantly reduces tool wear, without requiring auxiliary cooling from an internal cooling hole.

[0004] According to an embodiment of the present invention, a roughing round nose end mill includes a shank portion and a cutting edge portion. The cutting edge portion includes an end edge, an A-peripheral edge, and a B-peripheral edge. One end of the cutting edge portion is connected to the shank portion, and the end face of the other end is provided with a plurality of end edges. The circumferential surface of the cutting edge portion is provided with the A-peripheral edge and the B-peripheral edge, which are arranged at intervals around the axis of the shank portion and are spirally arranged along the axial direction of the shank portion. The A-peripheral edge is provided with a plurality of arc-shaped grooves along the spiral direction. The arc-shaped grooves are used for chip breaking and flow during cutting. The B-peripheral edge is provided with a plurality of roughing peripheral teeth arranged at intervals along the spiral direction.

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

[0006] The B-circle cutting edge is used for roughing, and the A-circle cutting edge is used for roughing after roughing. In this embodiment, several arc-shaped grooves are set on the A-circle cutting edge. The groove surface of the arc-shaped grooves can bend the chips in time and cause the rolled chips to break and become finely fragmented. This effectively reduces the friction and collision of chips on the back face. The finely fragmented chips can be discharged to the chip removal groove through the arc-shaped grooves. In addition to accommodating and discharging chips, the arc-shaped grooves can also serve as a coolant inlet space. The coolant can enter the cutting edge area more comprehensively with the help of the arc-shaped grooves, which is beneficial to improving the external cooling, chip removal, and lubrication of the tool. Overall, the practice of setting arc-shaped grooves on the circumferential cutting edge can change the chip breaking efficiency, flow frequency and cycle of the chips, realize the alternation of chip breaking and flow, and optimize the chip breaking effect and flow effect.

[0007] According to some embodiments of the present invention, the A peripheral cutting edge is provided with an A peripheral cutting edge rear cutting face, and an arc-shaped groove is recessed on the A peripheral cutting edge rear cutting face.

[0008] According to some embodiments of the present invention, the arcuate groove extends from the edge of the A peripheral cutting face away from the A peripheral cutting edge towards the A peripheral cutting edge.

[0009] According to some embodiments of the present invention, the arc groove is divided into a first arc groove and a second arc groove. The first arc groove and the second arc groove are arranged alternately along the spiral direction of the A peripheral cutting edge. On the surface direction of the back face of the A peripheral cutting edge, the extension length of the first arc groove and the extension length of the second arc groove are not equal.

[0010] According to some embodiments of the present invention, the A-peripheral cutting edge includes the A1-peripheral cutting edge and the A2-peripheral cutting edge, which are arranged at intervals around the axial direction of the shank, and the B-peripheral cutting edge is provided between the A1-peripheral cutting edge and the A2-peripheral cutting edge; both the A1-peripheral cutting edge and the A2-peripheral cutting edge are provided with arc-shaped grooves, and along the extension direction of the A-peripheral cutting edge, the arc-shaped grooves on the A1-peripheral cutting edge and the arc-shaped grooves on the A2-peripheral cutting edge are arranged alternately.

[0011] According to some embodiments of the present invention, a roughing groove is formed between two adjacent roughing teeth, and the roughing groove extends in a direction perpendicular to the axis of the handle.

[0012] According to some embodiments of the present invention, the helix angle of the A-peripheral blade is 40°, and the helix angle of the B-peripheral blade is 42°.

[0013] According to some embodiments of the present invention, the rake angles of both the A-circular cutting edge and the B-circular cutting edge are 4°. The back face of both the A-circular cutting edge and the B-circular cutting edge is provided with a first back angle δ1 and a second back angle δ2. The first back angle δ1 is a 10° arc back angle, and the second back angle δ2 is a 28° planar back angle. The width of the first back angle δ1 is 0.35mm.

[0014] According to some embodiments of the present invention, a chip removal groove is formed between peripheral cutting edge A and peripheral cutting edge B. The groove surface of the chip removal groove is provided with a plurality of sequentially connected chip removal arc surfaces around the axial direction of the tool holder. Two adjacent chip removal arc surfaces form a chip removal cutting edge at the connection position.

[0015] According to some embodiments of the present invention, a reinforcing portion is provided on the end cutting edge, the reinforcing portion including an end tooth reinforcing portion and a blade tip reinforcing portion, the end tooth reinforcing portion being provided on the rear cutting face of the end cutting edge; a plurality of end cutting edges are correspondingly provided with A peripheral cutting edge and B peripheral cutting edge, and the end cutting edge is connected with the corresponding A peripheral cutting edge and B peripheral cutting edge to form a blade tip, the blade tip reinforcing portion being provided on the blade tip.

[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 (axial angle) of a roughing round nose end mill according to an embodiment of the present invention;

[0019] Figure 2 This is a schematic diagram of the structure of a roughing round nose end mill according to an embodiment of the present invention (horizontal angle);

[0020] Figure 3 Regarding an embodiment of the present invention Figure 2 Schematic diagram of the BB cross section;

[0021] Figure 4 This is a schematic diagram of the blade portion according to an embodiment of the present invention;

[0022] Figure 5 This is a schematic diagram of the parameters of the peripheral cutting edge of a roughing round nose end mill according to an embodiment of the present invention;

[0023] Figure 6 This is a schematic diagram of the parameters of the end cutting edge of a roughing round nose end mill according to an embodiment of the present invention;

[0024] Figure 7 Regarding an embodiment of the present invention Figure 2 A schematic diagram of direction A;

[0025] Figure 8 Regarding an embodiment of the present invention Figure 7 A magnified view of a portion of point C.

[0026] Figure label:

[0027] Handle portion 100; Blade portion 200; End edge 210; End edge back face 211; A peripheral edge 220; A1 peripheral edge 221; A2 peripheral edge 222; A peripheral edge back face 223; B peripheral edge 230; B1 peripheral edge 231; B2 peripheral edge 232; Rough peripheral teeth 233; Rough cutting groove 234; Arc groove 240; First arc groove 241; Second arc groove 242; Chip removal groove 250; Chip removal arc surface 251; Chip removal cutting edge 252; Reinforcing part 260; End tooth reinforcing part 261; Blade tip reinforcing part 262; A peripheral edge helix angle α; B peripheral edge helix angle β; peripheral edge rake angle γ; peripheral edge first back angle δ1; peripheral edge second back angle δ2; end edge rake angle θ; end edge first back angle η1; end edge second back angle η2. Detailed Implementation

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] Please see Figures 1 to 4According to some embodiments of the present invention, a roughing round nose end mill includes a shank portion 100 and a cutting edge portion 200. The cutting edge portion 200 includes an end cutting edge 210, an A-peripheral cutting edge 220, and a B-peripheral cutting edge 230. One end of the cutting edge portion 200 is connected to the shank portion 100, and the end face of the other end is provided with a plurality of end cutting edges 210. The A-peripheral cutting edge 220 and the B-peripheral cutting edge 230 are respectively provided on the circumferential surface of the cutting edge portion 200. The A-peripheral cutting edge 220 and the B-peripheral cutting edge 230 are arranged at intervals around the axis of the shank portion 100, and the A-peripheral cutting edge 220 and the B-peripheral cutting edge 230 are respectively spirally arranged along the axial direction of the shank portion 100. The A-peripheral cutting edge 220 is provided with a plurality of arc-shaped grooves 240 along the spiral direction. The arc-shaped grooves 240 are used for chip breaking and flow during cutting. The B-peripheral cutting edge 230 is arranged at intervals along the spiral direction with a plurality of roughing peripheral teeth 233.

[0034] Please see Figure 4 The B-circumferential cutting edge 230 is used for roughing, and the A-circumferential cutting edge 220 is used for roughing after roughing. In this embodiment, several arc-shaped grooves 240 are set on the A-circumferential cutting edge 220. The groove surface of the arc-shaped grooves 240 is used to curl the chips in time and cause the curled chips to break and become finely fragmented. This effectively reduces the friction and collision of chips on the back face. The finely fragmented chips can be discharged to the chip removal groove 250 through the arc-shaped grooves 240. In addition to accommodating and discharging chips, the arc-shaped grooves 240 can also serve as a coolant inlet space. The coolant can enter the cutting edge area more comprehensively with the help of the arc-shaped grooves 240, which is beneficial to improving the external cooling, chip removal, and lubrication of the tool. Overall, the practice of setting arc-shaped grooves 240 on the peripheral cutting edge can change the chip breaking efficiency, flow frequency and cycle of the chips, realize the alternation of chip breaking and flow, and optimize the chip breaking effect and flow effect.

[0035] Please see Figure 4 The arc-shaped groove 240 extends from the edge of the back face 223 of the A peripheral cutting edge away from the cutting edge of the A peripheral cutting edge 220 towards the cutting edge of the A peripheral cutting edge. Thus, the arc-shaped groove 240 is a semi-circular groove structure, and the arc-shaped groove 240 does not contact the front cutting edge of the A peripheral cutting edge 220. That is to say, the arc-shaped groove 240 is not opened to the cutting edge. The parabolic edge is kept at a certain distance from the front cutting edge of the A peripheral cutting edge 220. This setting allows the cutting edge of the A peripheral cutting edge 220 to still have a complete cutting edge structure, maintaining the cutting strength and rigidity of the cutting edge. In addition, both ends of the groove edge are connected to the back cutting edge of the A peripheral cutting edge 220, and the broken chips can be discharged relatively smoothly through the arc-shaped groove 240 to the chip removal groove 250 between the two cutting edges.

[0036] In terms of functionality, the arc-shaped groove 240 forms a chip-breaking groove structure, enabling rapid chip breaking and removal; secondly, it forms a cooling groove structure, which is very beneficial for external coolant to enter the cutting edge from the A peripheral cutting edge flank 223, using the external high-pressure coolant to quickly remove chips from the cutting edge, providing good lubrication, rapid cooling, and chip removal, achieving an effect comparable to an internal cooling hole; thirdly, it forms a flow-retaining groove structure, which can effectively suppress the backward flow of workpiece material during cutting, thereby eliminating the size effect of surface roughness and facilitating the production of a smooth surface. Overall, using a peripheral cutting edge with several arc-shaped grooves 240 for machining can improve production efficiency and reduce production costs.

[0037] Please refer to [link / reference] for further information. Figure 3 A chip removal groove 250 is formed between the A-peripheral cutting edge 220 and the B-peripheral cutting edge 230. The groove surface of the chip removal groove 250 has several sequentially connected chip removal arc surfaces 251 arranged around the axis of the tool holder 100. Two adjacent chip removal arc surfaces 251 form a chip removal cutting edge 252 at the connection point. Specifically, the chip removal cutting edge 252 protrudes from the groove surface of the chip removal groove 250 and extends along the spiral direction of the chip removal groove 250. This groove configuration forms a multi-sloping groove structure. While ensuring sufficient rigidity of the tool, the several chip removal arc surfaces 251 maximize the chip-carrying space, resulting in smoother chip removal. Simultaneously, the several chip removal arc surfaces 251 produce better chip curling and breaking effects on the chips, further refining the chips and effectively avoiding problems such as chip entanglement and chipping caused by repeated cutting at the cutting edge.

[0038] Please see Figure 4 The arc-shaped groove 240 is divided into a first arc-shaped groove 241 and a second arc-shaped groove 242. The first arc-shaped groove 241 and the second arc-shaped groove 242 are arranged alternately along the extension direction of the A peripheral cutting edge 220. On the surface direction of the A peripheral cutting edge flank face 223, the extension length of the first arc-shaped groove 241 and the extension length of the second arc-shaped groove 242 are not equal. By setting the cutting edge widths of the odd-numbered grooves (e.g., the first arc-shaped groove 241) and the even-numbered grooves (e.g., the second arc-shaped groove 242) on the same cutting edge to be different, the staggered arrangement of the cutting edge widths is achieved. A larger peripheral cutting edge width is used to ensure the cutting strength and rigidity of the A peripheral cutting edge 220, while a smaller peripheral cutting edge width is used to improve the sharpness and chip removal capability of the A peripheral cutting edge 220.

[0039] Based on the above, the A-peripheral cutting edge 220 includes an A1-peripheral cutting edge 221 and an A2-peripheral cutting edge 222, which are arranged at intervals around the axis of the handle portion 100, and a B-peripheral cutting edge 230 is provided between the A1-peripheral cutting edge 221 and the A2-peripheral cutting edge 222; both the A1-peripheral cutting edge 221 and the A2-peripheral cutting edge 222 are provided with arc-shaped grooves 240, and the arc-shaped grooves 240 on the A1-peripheral cutting edge 221 and the A2-peripheral cutting edge 222 are provided with arc-shaped grooves 240. The arc-shaped grooves 240 are arranged in an alternating pattern to form an alternating arrangement on the teeth. For example, the A1 peripheral cutting edge 221 has a smaller cutting edge width in the odd-numbered groove (first arc-shaped groove 241) and a larger cutting edge width in the even-numbered groove (second arc-shaped groove 242). Then the A2 peripheral cutting edge 222 has a wider odd-numbered groove (second arc-shaped groove 242) and a narrower even-numbered groove (first arc-shaped groove 241). This structure ensures that there is a complete cutting edge during cutting.

[0040] The B-shaped blade 230 has several coarse leather teeth 233 arranged at intervals along the spiral direction. A coarse leather groove 234 is formed between two adjacent coarse leather teeth 233. The coarse leather groove 234 extends in a direction perpendicular to the axis of the handle 100. Specifically, the B-peripheral cutting edge 230 is divided into the B1-peripheral cutting edge 231 and the B2-peripheral cutting edge 232. Both the B1-peripheral cutting edge 231 and the B2-peripheral cutting edge 232 adopt the roughing cutting edge mode of a fixed-width grinding wheel. In the direction around the axis of the tool holder 100, several roughing peripheral teeth 233 on the B1-peripheral cutting edge 231 and several roughing peripheral teeth 233 on the B2-peripheral cutting edge 232 are staggered to each other, so that the B1-peripheral cutting edge 231 and the B2-peripheral cutting edge 232 can form overlapping and complete cutting edges during actual rotational machining. This can achieve rapid chip breaking and make the chips finer and prevent chip entanglement even during roughing and even full-cut cutting. At the same time, the staggered arrangement of the roughing teeth helps to prevent excessive cutting force, thereby playing a stabilizing role.

[0041] Please see Figure 2 The helix angle α of peripheral cutting edge A is 40°, and the helix angle β of peripheral cutting edge B is 42°. The larger helix angle provides sharper cutting performance and reduces the generation of cutting heat. At the same time, the larger helix angle structure results in a larger axial force component in actual machining compared to the smaller helix. Even with insufficient clamping force, the tool can still be clamped, making it less prone to vibration and runout, and providing good cutting stability.

[0042] Please see Figure 5 Both peripheral cutting edge A 220 and peripheral cutting edge B 230 are equipped with a peripheral cutting edge rake angle γ, which is 4°. The tool groove is made by a multi-bevel forming grinding wheel. The larger helix angles α and β combined with the 4° peripheral cutting edge rake angle γ still have good chipping resistance and wear resistance, even in roughing with a large amount of material removal or even full-cut roughing. The uniformity of tool wear is significantly better than that of a small helix angle combined with a small rake angle.

[0043] Please see Figure 5 Regarding other cutting parameters of the peripheral cutting edge, both peripheral cutting edge A (220) and peripheral cutting edge B (230) have a first relief angle δ1 and a second relief angle δ2 on the flank face. The first relief angle δ1 is a 10° arc relief angle, and the second relief angle δ2 is a 28° planar relief angle. The width of the first relief angle δ1 is 0.35mm. The smaller arc relief angle of 0.35mm combined with the larger second relief angle δ2 of 28° effectively reduces the cutting friction and heat generation, extending tool life. The larger second relief angle δ2 effectively avoids the impact and friction on the flank face caused by the high resilience of titanium alloy material, preventing chip adhesion and chipping due to continuous material rebound.

[0044] Please see Figure 6 Regarding the cutting parameters of the end cutter 210, the end cutter 210 adopts a structure in which the cutting length exceeds the shaft core, and the end cutter 210 is provided with a butterfly angle of 1°. The combination of the cutting length exceeding the shaft core and the 1° butterfly angle structure provides good cutting sharpness when the end cutter 210 is cutting, and the texture of the end cutter 210 is uniform and delicate. Even when using plunge milling or helical plunge milling, the end cutter 210 can produce excellent product surface flatness.

[0045] The end face 211 of the end blade 210 is provided with an end blade rake angle θ, an end blade first clearance angle η1 and an end blade second clearance angle η2. The end blade rake angle θ is 3°, the end blade first clearance angle η1 is 8.5-10°, the end blade second clearance angle η2 is 18-20°, and the width of the end blade first clearance angle η1 is 0.6mm. The double clearance angle on the end blade 210 can reduce the friction on the cutting edge 200 during deep cutting and also improve the chip removal performance during cutting.

[0046] Please see Figure 7 and Figure 8 The end blade 210 is provided with a reinforcing part 260, which includes an end tooth reinforcing part 261 and a blade tip reinforcing part 262. The end tooth reinforcing part 261 is provided on the back face 211 of the end blade. Several end blades 210 are correspondingly provided with A peripheral blades 220 and B peripheral blades 230, and the end blades 210 are connected with the corresponding A peripheral blades 220 and B peripheral blades 230 to form a blade tip. The blade tip reinforcing part 262 is provided on the blade tip.

[0047] Please see Figure 8Along the width direction of the end face 211, the width of the end tooth reinforcement 261 is 0.22±0.015mm. The end tooth reinforcement forms a reinforcing surface for the cutting edge of the end face 210. This end tooth reinforcement, combined with the aforementioned positive end face rake angle θ, can provide a sharp rake angle for the bottom edge, making the bottom edge cutting easier and reducing the generation of cutting heat. In addition, the end tooth reinforcement 261 has a certain width, which can improve the cutting strength of the end face 210. The tip reinforcement 262 forms a triangular tip reinforcement surface on the tip. The setting of the tip reinforcement surface can transform the point contact during cutting into a surface contact form, thereby increasing the contact area between the roughing round nose end mill and the workpiece. Thus, the cutting edge surface of the end blade 210 is provided with a reinforcing surface. The end tooth reinforcement 261 and the tool tip reinforcement 262 are combined to work together with the end blade 210 to complete the cutting action, which can enable the chips to be broken and removed quickly, reduce the chip dwell time, and extend the tool life.

[0048] Overall, this invention improves upon conventional tool structures. Without requiring internal cooling holes for auxiliary cooling, the invention significantly reduces tool wear and improves edge cooling and chip breaking by incorporating features such as the arc-shaped groove 240 and multi-arc chip removal groove 250. This results in a high-performance, high-efficiency, and highly wear-resistant general-purpose titanium alloy roughing round nose cutter.

[0049] 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 roughing round nose end mill, characterized in that, include: Handle (100); The blade portion (200) includes an end blade (210), an A-peripheral blade (220), and a B-peripheral blade (230). One end of the blade portion (200) is connected to the handle portion (100), and the end face of the other end is provided with a plurality of the end blades (210). The A-peripheral blade (220) and the B-peripheral blade (230) are respectively provided on the circumferential surface of the blade portion (200). The A-peripheral blade (220) and the B-peripheral blade (230) are arranged at intervals around the axis of the handle portion (100), and the A-peripheral blade (220) and the B-peripheral blade (230) are respectively spirally arranged along the axial direction of the handle portion (100). The A peripheral cutting edge (220) is provided with a number of arc-shaped grooves (240) along the spiral direction. The arc-shaped grooves (240) are used for chip breaking and flow during the cutting process. The B peripheral cutting edge (230) is provided with a number of rough peripheral teeth (233) arranged at intervals along the spiral direction. in, The A-peripheral cutting edge (220) is provided with an A-peripheral cutting edge back face (223), and the arc-shaped groove (240) is recessed on the A-peripheral cutting edge back face (223); The arc-shaped groove (240) extends from the edge of the A peripheral cutting edge (223) away from the cutting edge of the A peripheral cutting edge (220) towards the cutting edge of the A peripheral cutting edge; The arc groove (240) is divided into a first arc groove (241) and a second arc groove (242). The first arc groove (241) and the second arc groove (242) are arranged alternately along the spiral direction of the A-circumferential cutting edge (220). On the surface direction of the back face (223) of the A-circumferential cutting edge, the extension length of the first arc groove (241) and the extension length of the second arc groove (242) are not equal.

2. The roughing round nose end mill according to claim 1, characterized in that, The A-peripheral blade (220) includes an A1-peripheral blade (221) and an A2-peripheral blade (222). The A1-peripheral blade (221) and the A2-peripheral blade (222) are arranged at intervals around the axis of the handle portion (100), and the B-peripheral blade (230) is provided between the A1-peripheral blade (221) and the A2-peripheral blade (222). The A1-peripheral blade (221) and the A2-peripheral blade (222) are both provided with arc-shaped grooves (240), and along the extension direction of the A-peripheral blade (220), the arc-shaped grooves (240) on the A1-peripheral blade (221) and the arc-shaped grooves (240) on the A2-peripheral blade (222) are arranged alternately.

3. The roughing round nose end mill according to claim 1, characterized in that, A rough leather cutting groove (234) is formed between two adjacent rough leather teeth (233), and the rough leather cutting groove (234) extends in a direction perpendicular to the axis of the handle (100).

4. The roughing round nose end mill according to claim 1, characterized in that, The helix angle (α) of the A-perimeter is 40°, and the helix angle (β) of the B-perimeter is 42°.

5. The roughing round nose end mill according to claim 1, characterized in that, Both the A-peripheral cutting edge (220) and the B-peripheral cutting edge (230) are provided with a rake angle (γ), which is 4°. The back face of the A-peripheral cutting edge (220) and the B-peripheral cutting edge (230) are provided with a first back angle (δ1) and a second back angle (δ2). The first back angle (δ1) is a 10° arc back angle, and the second back angle (δ2) is a 28° planar back angle. The width of the first back angle (δ1) is 0.35mm.

6. The roughing round nose end mill according to claim 1, characterized in that, A chip removal groove (250) is formed between the A peripheral cutting edge (220) and the B peripheral cutting edge (230). The groove surface of the chip removal groove (250) is provided with a plurality of sequentially connected chip removal arc surfaces (251) around the axis of the tool holder (100). Two adjacent chip removal arc surfaces (251) form a chip removal cutting edge (252) at the connection position.

7. The roughing round nose end mill according to claim 1, characterized in that, The end blade (210) is provided with a reinforcing part (260), the reinforcing part (260) includes an end tooth reinforcing part (261) and a blade tip reinforcing part (262), the end tooth reinforcing part (261) is provided on the back face of the end blade (210); a plurality of end blades (210) are correspondingly provided with the A peripheral blade (220) and the B peripheral blade (230), and the end blade (210) is connected with the corresponding A peripheral blade (220) and the B peripheral blade (230) to form a blade tip, and the blade tip reinforcing part (262) is provided on the blade tip.

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