Efficient four-edge milling cutter with unequal teeth and unequal spirals and manufacturing process of efficient four-edge milling cutter

Abstract

The invention provides a high-efficiency four-edge milling cutter with unequal teeth and unequal spirals and a manufacturing process thereof. The high-efficiency four-edge milling cutter with unequal teeth and unequal spirals comprises a handle part, a side edge part and an end edge part, the helical angles of the first cutting edge and the third cutting edge are the same, and the helical angles of the second cutting edge and the fourth cutting edge are the same but are different from the helical angle of the first cutting edge; the distances between the first cutting edge, the second cutting edge, the third cutting edge and the fourth cutting edge and the rotating center of the efficient unequal-tooth unequal-spiral four-edge milling cutter are equal; the first end edge tooth and the third end edge tooth are the same in indexing, and the second end edge tooth and the fourth end edge tooth are the same in indexing but different from the first end edge tooth in indexing. The end edge first tooth, the end edge second tooth, the end edge third tooth and the end edge fourth tooth are in central symmetry relative to the rotation center of the efficient unequal-tooth unequal-spiral four-edge milling cutter. The efficient four-edge milling cutter with the unequal teeth and the unequal spirals has the advantages of high end milling efficiency, high side milling damping surface smoothness, high-efficiency and rapid large-feed machining and the like.

Description

Technical Field

[0001] This application belongs to the field of milling cutter manufacturing technology, and more specifically, relates to a high-efficiency unequal tooth unequal helical four-flute milling cutter and its manufacturing process. Background Technology

[0002] Traditional milling cutter designs typically employ a two-flute, equally spaced helix indexing configuration. This design has several drawbacks: First, because the feed rate is directly proportional to the feed per tooth and the number of teeth, the feed rate of a traditional double-flute milling cutter is limited at a given spindle speed, resulting in low machining efficiency. Second, the traditional equally spaced helix indexing design is prone to resonance due to the uniformity of the fixed frequency, causing significant wobble and vibration in the milling cutter. This not only leads to noticeable defects on the machined surface of the workpiece, affecting the surface quality of the product, but also easily causes chipping and accelerated wear, reducing tool life. Summary of the Invention

[0003] The purpose of this application is to provide a high-efficiency unequal tooth unequal helical four-flute end mill to solve the above-mentioned technical problems existing in the prior art.

[0004] To achieve the above objectives, the technical solution adopted in this application is: to provide a high-efficiency unequal-tooth, unequal-helical four-flute end mill, comprising:

[0005] handle,

[0006] The side cutting edge includes a base and four cutting edges—a first, a second, a third, and a fourth—that protrude helically from the outer circumference of the base. The second cutting edge is located between the first and third cutting edges, and the fourth cutting edge is located between the first and third cutting edges and opposite to the second cutting edge. The first and third cutting edges have the same helix angle, the second and fourth cutting edges have the same helix angle, and the helix angles of the first and second cutting edges are different. The first, second, third, and fourth cutting edges are all equidistant from the rotation center of the high-efficiency unequal-tooth, unequal-tooth, helical four-flute end mill.

[0007] The end cutting edge, located at the front end of the bottom bar away from the shank, includes a first end cutting tooth integrally formed on the front end of the first cutting edge, a second end cutting tooth integrally formed on the front end of the second cutting edge, a third end cutting tooth integrally formed on the front end of the third cutting edge, and a fourth end cutting tooth integrally formed on the front end of the fourth cutting edge. The first end cutting tooth and the third end cutting tooth have the same index, the second end cutting tooth and the fourth end cutting tooth have the same index, and the first end cutting tooth and the second end cutting tooth have different indexes. The first end cutting tooth, the second end cutting tooth, the third end cutting tooth and the fourth end cutting tooth are all centrally symmetrically arranged with respect to the rotation center of the high-efficiency unequal tooth unequal helical four-flute end mill.

[0008] Optionally, the helix angle of the first cutting edge is smaller than that of the second cutting edge; the index of the first tooth of the end edge is larger than that of the second tooth of the end edge.

[0009] Optionally, the helix angle of the first cutting edge is 36°, and the helix angle of the second cutting edge is 38°; the graduation of the first tooth of the end edge is 95°, and the graduation of the second tooth of the end edge is 85°.

[0010] Optionally, a spiral chip groove is formed between two adjacent cutting edges among the first, second, third, and fourth cutting edges, and the inner wall of the chip groove is set with a circular arc transition.

[0011] Optionally, the bottom radius of the chip flute is R1, the bottom extension radius of the chip flute to ensure the width of the cylinder is R2, the tool radius of the high-efficiency unequal tooth unequal helical four-flute end mill is R3, the ratio of R1 to R3 is 0.618:1, and the ratio of R2 to R3 is 0.618:1.

[0012] Optionally, the high-efficiency unequal tooth unequal helical four-flute end mill is made of carbide, and the surfaces of the side cutting edge and the end cutting edge are coated with a hardened coating.

[0013] This application also proposes a manufacturing process for a high-efficiency unequal-tooth, unequal-tooth, spiral four-flute end mill, used to manufacture the high-efficiency unequal-tooth, unequal-tooth, spiral four-flute end mill as described above. The manufacturing process for the high-efficiency unequal-tooth, unequal-tooth, spiral four-flute end mill includes the following steps:

[0014] The blank is cut into columnar blades according to the preset dimensions on the drawing;

[0015] The tool body is centerlessly ground to obtain a tool body with qualified outer diameter;

[0016] The tool body is processed by step difference to obtain a tool body with qualified dimensions for each step and the outer circle dimension of the cutting edge;

[0017] The cutter body is CNC machined into milling cutter preparation bodies with dimensions conforming to the drawing requirements using a CNC machine tool;

[0018] After the cutting edge of the milling cutter preparation body is dulled and a hardened coating is applied, a high-efficiency unequal tooth unequal helical four-flute milling cutter is formed.

[0019] Optionally, after the step of cutting the blank into a columnar blade according to the preset dimensions on the drawing, and before the step of centerlessly grinding the blade to obtain a blade with qualified outer diameter, the following step is also included: using a chamfering machine to chamfer the blade according to the drawing requirements.

[0020] Optionally, after the step of centerlessly grinding the tool body to obtain a tool body with qualified outer diameter, and before the step of performing step processing on the tool body to obtain a tool body with qualified dimensions of each step and outer diameter of the cutting edge, the following step is also included: laser marking the shank of the tool body according to the marking requirements.

[0021] Optionally, an initial inspection is required after obtaining the first tool body in the centerless grinding process;

[0022] After the step difference processing and before CNC machining, the shank should be used as a reference to inspect the cutting edge diameter, runout, step length and surface finish, and the first inspection should be carried out to check whether the markings are complete.

[0023] After obtaining the first milling cutter preparation body through CNC machining, an initial inspection is required. The initial inspection includes checking the cutting edge for serrations and chipping under a 100x magnifying glass. During CNC machining, a routine inspection is conducted. After CNC machining is completed and before passivation treatment, a full inspection of the milling cutter preparation body is required. The full inspection includes checking the cutting edge for cracks, chipping, and serrations under a 150x magnifying glass.

[0024] After the process of passivating the cutting edge and applying a hardening coating to the pre-made end mill body to form a high-efficiency unequal tooth unequal helical four-flute end mill, the final product inspection is also included. The final product inspection includes checking under a 100x magnifying glass whether the markings are correct, whether the edge is sharpened, whether the outer diameter and length of the cutting edge are correct, and whether the cutting edge has any dents, chips, or cracks.

[0025] The beneficial effects of the high-efficiency unequal-tooth, unequal-tooth, unequal-helical four-flute end mill and its manufacturing process provided in this application are as follows: This high-efficiency unequal-tooth, unequal-helical four-flute end mill has multiple advantages: First, this end mill uses a four-flute configuration. Compared with traditional double-flute end mills, the increase in the number of flutes can achieve a multiple increase in feed rate at the same rotational speed, thereby significantly improving the metal removal rate, i.e., machining efficiency, which is conducive to shortening the production cycle. At the same time, the increase in the number of flutes also helps to reduce chip thickness and improve the surface quality of the machined surface. Second, the setting of the helix angle of the first cutting edge and the helix angle of the second cutting edge adopted in this application can effectively disperse the cutting force due to the difference in helix angle during the machining process, greatly eliminating the resonance phenomenon during the cutting process. At the same time, the design in this application that ensures that the four circular cutting edges are all equidistant from the rotation center of the end mill also helps to further reduce tool vibration. The reduction of end mill vibration can improve tool stability, improve the surface quality of the machined surface, and extend the tool life. Furthermore, the first and second teeth of the end-cutting edge used in this application have different indexing values, and the four end-cutting edges are symmetrically arranged relative to the center of rotation of the tool. This not only effectively compensates for the loss of base strength caused by the inconsistent helix angles of the side-cutting edges, but also effectively disperses the cutting force during machining. In other words, it ensures tool rigidity and reduces vibration during high-efficiency heavy cutting. In summary, this high-efficiency unequal tooth unequal helical four-flute end mill has comprehensive advantages such as high end milling efficiency, side milling vibration reduction, high surface finish, high-efficiency and high-feed machining, high milling efficiency, high material removal, and a wide range of machined products. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 A schematic diagram of the structure of the high-efficiency unequal tooth unequal helical four-flute end mill provided in the embodiments of this application;

[0028] Figure 2 A side view of the high-efficiency unequal tooth unequal helical four-flute end mill provided in the embodiments of this application;

[0029] Figure 3 A front view of the high-efficiency unequal tooth unequal helical four-flute end mill provided in the embodiments of this application;

[0030] Figure 4 A cross-sectional view of the chip groove of the high-efficiency unequal tooth unequal helical four-flute end mill provided in the embodiments of this application;

[0031] Figure 5 A flowchart illustrating the manufacturing process of a high-efficiency unequal-tooth, unequal-tooth, spiral four-flute end mill provided in this application embodiment.

[0032] Explanation of icon numbers:

[0033] Detailed Implementation

[0034] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0035] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0036] It should also be noted that the directional terms such as left, right, up, and down in the embodiments of this application are only relative concepts or are based on the normal use state of the product, and should not be considered as restrictive.

[0037] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this 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 this application.

[0038] 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 technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0039] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0040] The embodiments of this application 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 intended to explain this application, and should not be construed as limiting this application.

[0041] This application provides a high-efficiency unequal tooth unequal helical four-flute end mill.

[0042] Please see Figures 1 to 3In one embodiment, the high-efficiency unequal tooth unequal helical four-flute end mill includes a shank 100, a side cutting edge 200, and an end cutting edge 300. Specifically, the side cutting edge 200 includes a base and a first cutting edge 220, a second cutting edge 230, a third cutting edge 240, and a fourth cutting edge 250 that protrude helically from the outer circumference of the base. The second cutting edge 230 is located between the first cutting edge 220 and the third cutting edge 240, and the fourth cutting edge 250 is located between the first cutting edge 220 and the third cutting edge 240 and is opposite to the second cutting edge 230. The first cutting edge 220 and the third cutting edge 240 have the same helix angle x, and the second cutting edge 230 and the fourth cutting edge 250 have the same helix angle y. The helix angle of the first cutting edge 220 is different from that of the second cutting edge 230. The first cutting edge 220, the second cutting edge 230, the third cutting edge 240, and the fourth cutting edge 250 are all equidistant from the rotation center O of the high-efficiency unequal tooth unequal helical four-flute end mill. The end-cutting portion 300 is located at the front end of the bottom bar away from the shank portion 100, and includes a first end-cutting tooth 310 integrally formed at the front end of the first cutting edge 220, a second end-cutting tooth 320 integrally formed at the front end of the second cutting edge 230, a third end-cutting tooth 330 integrally formed at the front end of the third cutting edge 240, and a fourth end-cutting tooth 340 integrally formed at the front end of the fourth cutting edge 250; the end-cutting tooth 310 and the third end-cutting tooth 330 have the same scale division α and γ, the end-cutting tooth 320 and the fourth end-cutting tooth 340 have the same scale division β and δ, and the end-cutting tooth 310 and the second end-cutting tooth 320 have different scale divisions; the end-cutting tooth 310, the second end-cutting tooth 320, the third end-cutting tooth 330 and the fourth end-cutting tooth 340 are all centrally symmetrically arranged with respect to the rotation center O of the high-efficiency unequal tooth unequal helical four-flute end mill.

[0043] Based on this design, in this embodiment, the high-efficiency unequal-tooth, unequal-helix four-flute end mill has multiple advantages: First, the end mill uses a four-flute configuration. Compared to traditional double-flute end mills, the increased number of flutes allows for a significant increase in feed rate at the same rotational speed, thereby significantly improving metal removal rate and machining efficiency, which helps shorten the production cycle. Simultaneously, the increased number of flutes also helps reduce chip thickness and improve the surface finish. Second, the different helix angles of the first cutting edge 220 and the second cutting edge 230 used in this application effectively disperse the cutting force during machining due to the difference in helix angles, greatly eliminating resonance during the cutting process. Furthermore, the design in this application, ensuring that all four circular cutting edges are equidistant from the end mill's rotation center, further reduces tool vibration. Reduced end mill vibration improves tool stability, enhances surface finish, and extends tool life. Furthermore, the first tooth 310 and the second tooth 320 of the end cutting edge used in this application have different indexes, and the four end cutting edges are symmetrically arranged with respect to the center of rotation of the tool. This not only effectively compensates for the loss of base strength caused by the inconsistent helix angle of the side cutting edge 200, but also effectively disperses the cutting force during the machining process. That is, in the process of high-efficiency heavy cutting, both tool rigidity and vibration are guaranteed. In summary, this high-efficiency unequal tooth unequal helical four-flute end mill has comprehensive advantages such as high end milling efficiency, side milling vibration reduction, high surface finish, high-efficiency and high-feed machining, high milling efficiency, high material removal, and a wide range of machined products.

[0044] It should be noted that since the feed rate of a milling cutter at a given spindle speed is positively correlated with both the feed per tooth and the number of teeth, increasing the number of cutting edges to four can multiply the feed rate at the same spindle speed, significantly improving machining efficiency and shortening the production cycle. In traditional helical milling cutter settings, the spacing between the helical side edges is the same, meaning the time interval between each side edge contacting the workpiece during milling is also the same. Therefore, when cutting the workpiece at a fixed frequency, the shared natural frequencies of the machine tool, cutting tool, and fixture easily lead to resonance, causing significant vibration in the milling cutter. This results in defects on the machined surface, severely affecting surface quality, reducing tool stability, accelerating tool wear, and shortening tool life. The unequal tooth and unequal helical design of this application allows the tool to withstand more complex cutting forces during milling, such as, but not limited to, radial forces, axial forces, and torque. It also provides more support points to distribute cutting forces, reducing tool runout and vibration. Higher rigidity results in better dimensional and shape accuracy, as well as superior surface finish, allowing for greater depths and widths of cut. This enhanced rigidity and stability reduces vibration-induced chipping and wear, extending tool life. Furthermore, more cutting edges mean a smaller chip thickness at the same feed per tooth. A smaller chip thickness generally helps reduce cutting forces, burrs, and a smoother surface. This allows the high-efficiency unequal tooth and unequal helical four-flute end mill to provide a smoother cutting process and more consistent surface texture in finishing, effectively improving surface quality. Therefore, this high-efficiency unequal tooth and unequal helical four-flute end mill better balances versatility and performance, making it the preferred choice for applications seeking higher efficiency, better rigidity and stability, and superior surface quality, especially suitable for semi-finishing and finishing.

[0045] Please see Figure 2 In this embodiment, the helix angle of the first cutting edge 220 is smaller than that of the second cutting edge 230; the graduation of the first end-edge tooth 310 is larger than that of the second end-edge tooth 320. Specifically, the helix angle of the first cutting edge 220 is 36°, and the helix angle of the second cutting edge 230 is 38°; the graduation of the first end-edge tooth 310 is 95°, and the graduation of the second end-edge tooth 320 is 85°. It can be understood that under these preferred angles of helix angle and graduation, this high-efficiency unequal-tooth unequal-helix four-flute end mill can achieve better performance.

[0046] Please see Figures 1 to 3In this embodiment, a spiral chip-receiving groove 400 is formed between adjacent cutting edges of the first cutting edge 220, the second cutting edge 230, the third cutting edge 240, and the fourth cutting edge 250. The inner wall of the chip-receiving groove 400 is rounded. This rounded transition of the inner wall greatly reduces chip removal resistance, resulting in smoother chip removal and better heat dissipation.

[0047] Refer to together Figure 4 In this embodiment, the bottom radius of the chip groove 400 is R1, the radius of the arc transition of the bottom of the chip groove 400 to ensure the width of the cylinder is R2, and the tool radius of the high-efficiency unequal tooth unequal helical four-flute end mill is R3. The ratio of R1 to R3 is 0.618:1, and the ratio of R2 to R3 is also 0.618:1, which is the golden ratio. Here, R1 is approximately equal to R2. Figure 4 In the equation n1=n2=n3=n4, n1, n2, n3, and n4 represent the groove bottom extensions of the first cutting edge 220, the second cutting edge 230, the third cutting edge 240, and the fourth cutting edge 250, respectively, ensuring the cylindrical width. This can be precisely calculated using the helix angle and indexing. It can be understood that this precisely designed groove shape ensures the strength of the substrate while maximizing the chip removal space.

[0048] It should also be noted that the high-efficiency unequal-tooth, unequal-tooth helical four-flute end mill is made of cemented carbide, and both the side cutting edge 200 and the end cutting edge 300 are coated with a hardened coating. Specifically, in this embodiment, the cemented carbide material is preferably a stainless steel cemented carbide material containing elements such as tungsten, and the hardened coating is preferably a PVD coating. Of course, in other embodiments, suitable cemented carbide materials and hardened coatings can be used according to actual needs.

[0049] This application also proposes a manufacturing process for a high-efficiency unequal-tooth, unequal-tooth, spiral four-flute end mill. This manufacturing process is used to manufacture the aforementioned high-efficiency unequal-tooth, unequal-tooth, spiral four-flute end mill. The specific structure of the high-efficiency unequal-tooth, unequal-tooth, spiral four-flute end mill is as described in the above embodiments. Since this manufacturing process for the high-efficiency unequal-tooth, unequal-tooth, spiral four-flute end mill adopts all the technical solutions of all the above embodiments, it also has all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be elaborated here.

[0050] Please see Figure 5 In this embodiment, the manufacturing process of the high-efficiency unequal tooth unequal helical four-flute end mill includes the following steps:

[0051] S1. Cut the blank into a columnar blade according to the preset dimensions on the drawing;

[0052] S2. The tool body is centerlessly ground to obtain a tool body with qualified outer diameter;

[0053] S3. Perform step processing on the tool body to obtain a tool body with qualified dimensions for each step and the outer circle dimension of the cutting edge;

[0054] S4. The cutter body is CNC machined into milling cutter preparation bodies with dimensions conforming to the drawing requirements using a CNC machine tool;

[0055] S5. After the cutting edge of the milling cutter preparation body is dulled and a hardened coating is applied, a high-efficiency unequal tooth unequal helical four-flute milling cutter is formed.

[0056] Here, centerless grinding offers the advantage of high precision, facilitating the rapid production of regularly shaped cutter bodies. Specifically, the cutter body needs to be machined to an outer diameter of 10.0 mm according to the drawings, with precise control over the roundness and runout of the outer diameter. Step processing refers to machining a stepped structure on the milling cutter body, creating precise step differences in diameter or height at different locations to meet the specific functional requirements of the tool. Edge dulling is a crucial post-processing step in milling cutter manufacturing. It involves machining tiny rounded corners or chamfers of several micrometers to tens of micrometers on the cutting edge using mechanical, chemical, or electrochemical methods. This removes microscopic defects on the cutting edge, making the sharp edge "dull" but more durable. Furthermore, hardening coating is a key surface treatment technology in milling cutter manufacturing. It involves depositing one or more layers of high-hardness, high-wear-resistant thin film materials on the tool substrate surface. Its core function is to significantly improve the hardness, wear resistance, and service life of the cutting edge without altering the toughness of the tool substrate.

[0057] Furthermore, in this embodiment, after the step of cutting the blank according to the preset dimensions on the drawing to form a columnar blade, and before the step of centerlessly grinding the blade to obtain a blade with qualified outer diameter, the following step is also included: using a chamfering machine to chamfer the blade according to the drawing requirements. Specifically, when performing the chamfering, it is necessary to chamfer according to the drawing, for example, C0.75 mm, and attention should be paid to ensuring that the chamfering quality is uniform.

[0058] Furthermore, in this embodiment, after the step of centerlessly grinding the blade to obtain a blade with qualified outer diameter, and before the step of performing step processing on the blade to obtain a blade with qualified dimensions of each step and outer diameter of the cutting edge, the following step is also included: laser marking the shank 100 of the blade according to the marking requirements.

[0059] Furthermore, in this embodiment, a first inspection is required after obtaining the first tool body in the centerless grinding process;

[0060] After the step difference processing and before CNC machining, the cutting edge diameter, runout, step length and surface finish should be inspected with the shank 100 as the reference, and the first inspection should be carried out to check whether the markings are complete.

[0061] After obtaining the first milling cutter preparation body through CNC machining, an initial inspection is required. The initial inspection includes checking the cutting edge for serrations and chipping under a 100x magnifying glass. During CNC machining, a routine inspection is conducted. After CNC machining is completed and before passivation treatment, a full inspection of the milling cutter preparation body is required. The full inspection includes checking the cutting edge for cracks, chipping, and serrations under a 150x magnifying glass.

[0062] After the process of passivating the cutting edge and applying a hardening coating to the pre-made end mill body to form a high-efficiency unequal tooth unequal helical four-flute end mill, the final product inspection is also included. The final product inspection includes checking under a 100x magnifying glass whether the markings are correct, whether the edge is sharpened, whether the outer diameter and length of the cutting edge are correct, and whether the cutting edge has any dents, chips, or cracks.

[0063] It is understandable that conducting various first-pass inspections and comprehensive tests in key processes helps to achieve strict control over the quality of milling cutters and ensure that the product yield of the tools meets the standards.

[0064] Finally, the high-efficiency unequal tooth unequal helical four-flute end mills need to be packaged. When packaging, care should be taken to clean different types of end mills separately and mixing of materials is prohibited.

[0065] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A high-efficiency unequal-tooth, unequal-tooth, helical four-flute end mill, characterized in that, include: handle, The side cutting edge includes a base and four cutting edges—a first, a second, a third, and a fourth—that protrude helically from the outer circumference of the base. The second cutting edge is located between the first and third cutting edges, and the fourth cutting edge is located between the first and third cutting edges and opposite to the second cutting edge. The first and third cutting edges have the same helix angle, the second and fourth cutting edges have the same helix angle, and the helix angles of the first and second cutting edges are different. The first, second, third, and fourth cutting edges are all equidistant from the rotation center of the high-efficiency unequal-tooth, unequal-tooth, helical four-flute end mill. The end-cutting portion, located at the front end of the base bar away from the shank, includes a first end-cutting tooth integrally formed on the front end of the first cutting edge, a second end-cutting tooth integrally formed on the front end of the second cutting edge, a third end-cutting tooth integrally formed on the front end of the third cutting edge, and a fourth end-cutting tooth integrally formed on the front end of the fourth cutting edge. The first and third end-cutting teeth have the same pitch, the second and fourth end-cutting teeth have the same pitch, and the first and second end-cutting teeth have different pitches. The first, second, third, and fourth end-cutting teeth are all centrally symmetrically arranged with respect to the rotation center of the high-efficiency unequal tooth unequal helical four-flute end mill.

2. The high-efficiency unequal-tooth, unequal-tooth, spiral four-flute end mill as described in claim 1, characterized in that, The helix angle of the first cutting edge is smaller than that of the second cutting edge; the graduation of the first tooth of the end edge is larger than that of the second tooth of the end edge.

3. The high-efficiency unequal-tooth, unequal-tooth, spiral four-flute end mill as described in claim 2, characterized in that, The first cutting edge has a helix angle of 36°, and the second cutting edge has a helix angle of 38°; the first tooth of the end cutting edge has a graduation of 95°, and the second tooth of the end cutting edge has a graduation of 85°.

4. The high-efficiency unequal-tooth, unequal-tooth, spiral four-flute end mill as described in claim 2, characterized in that, A spiral chip-receiving groove is formed between two adjacent cutting edges among the first cutting edge, the second cutting edge, the third cutting edge, and the fourth cutting edge, and the inner wall surface of the chip-receiving groove is set with a circular arc transition.

5. The high-efficiency unequal-tooth, unequal-tooth, helical four-flute end mill as described in any one of claims 4, characterized in that, The bottom arc radius of the chip groove is R1, the arc transition radius of the bottom extension of the chip groove to ensure the width of the cylinder is R2, the tool radius of the high-efficiency unequal tooth unequal spiral four-flute end mill is R3, the ratio of R1 to R3 is 0.618:1, and the ratio of R2 to R3 is 0.618:

1.

6. The high-efficiency unequal-tooth, unequal-tooth, helical four-flute end mill as described in any one of claims 1 to 4, characterized in that, The high-efficiency unequal tooth unequal helical four-flute end mill is made of cemented carbide, and the surfaces of the side cutting edge and the end cutting edge are coated with a hardened coating.

7. A manufacturing process for a high-efficiency unequal-tooth, unequal-tooth, helical four-flute end mill, characterized in that, For manufacturing the high-efficiency unequal-tooth unequal-tooth helical four-flute end mill as described in any one of claims 1 to 6, the manufacturing process of the high-efficiency unequal-tooth unequal-tooth helical four-flute end mill includes the following steps: The blank is cut into columnar blades according to the preset dimensions on the drawing; The tool body is subjected to centerless grinding to obtain a tool body with qualified outer diameter; The tool body is subjected to step processing to obtain a tool body with qualified dimensions for each step and outer circle of the cutting edge; The cutter body is CNC machined into milling cutter preparatory bodies with dimensions conforming to the drawing requirements using a CNC machine tool; The high-efficiency unequal tooth unequal helical four-flute end mill is formed by subjecting the milling cutter preparation body to edge passivation treatment and coating with a hardening coating.

8. The manufacturing process of the high-efficiency unequal tooth unequal helical four-flute end mill as described in claim 6, characterized in that, After the step of cutting the blank into a columnar blade according to the preset dimensions on the drawing, and before the step of centerlessly grinding the blade to obtain a blade with qualified outer diameter, the following step is also included: using a chamfering machine to chamfer the blade according to the drawing requirements.

9. The manufacturing process of the high-efficiency unequal tooth unequal helical four-flute end mill as described in claim 7, characterized in that, After the step of centerlessly grinding the blade body to obtain a blade body with qualified outer diameter, and before the step of performing step processing on the blade body to obtain a blade body with qualified step dimensions and blade outer diameter, the following step is also included: laser marking the shank of the blade body according to the marking requirements.

10. The manufacturing process of the high-efficiency unequal-tooth, unequal-tooth, spiral four-flute end mill as described in claim 9, characterized in that, After obtaining the first cutter body through the centerless grinding process, a first inspection is required. After the aforementioned step processing and before CNC machining, the shank should be used as a reference to inspect the cutting edge diameter, runout, step length, and surface finish, and the first inspection should be conducted to ensure the markings are complete. After obtaining the first milling cutter preparation body through CNC machining, an initial inspection is required. The initial inspection includes checking the cutting edge for serrations and chipping under a 100x magnifying glass. During CNC machining, a routine inspection is performed. After CNC machining is completed and before the passivation treatment is performed, a full inspection of the milling cutter preparation body is required. The full inspection includes checking the cutting edge for cracks, chipping, and serrations under a 150x magnifying glass. After the step of forming the high-efficiency unequal tooth unequal helical four-flute end mill by performing edge passivation treatment and coating hardening treatment on the end mill preparation body, the product inspection is also included. The product inspection includes checking whether the markings are correct, whether the edge is sharpened, whether the outer diameter and length of the cutting edge are correct, and whether the cutting edge has dents, chips, and cracks under a 100x magnifying glass.

Images