A multi-fluted square shoulder milling insert

Abstract

The application discloses a multi-blade square shoulder milling insert and belongs to the field of metal cutting processing, which comprises an upper surface, a lower bottom surface, a side surface and a macro main cutting edge, the side surface is provided with a plurality of grooves along the length direction and separates the macro main cutting edge into a plurality of sub-cutting edges. A macro inclination A is formed between the main inclination line of the macro main cutting edge and the lower bottom surface, and A is 13-17 degrees. An independent inclination alpha is formed between the line of the sub-cutting edge and the lower bottom surface, and alpha is 3-7 degrees. The macro inclination of the cutting edge is greater than the independent inclination. According to the force decomposition rule, the greater macro inclination can reduce the radial resistance of the insert, inhibit the cutting vibration of the tool to a certain extent, and reduce the damage degree of the cutting resistance to the cutting edge. In addition, the sub-cutting edge has a smaller independent inclination, can realize a larger wedge angle, improves the strength of the tool tip, and reduces the damage probability of the tool tip.

Description

Technical Field

[0001] This invention belongs to the field of metal cutting and machining, specifically a multi-bladed square shoulder milling insert. Background Technology

[0002] Square shoulder milling cutters can machine two surfaces simultaneously, which can be viewed as a combination of milling two perpendicular surfaces at the same time. Square shoulder milling inserts typically have a 90° principal cutting edge angle and are suitable for applications such as slot milling and cavity milling. Generally, the inserts have a long cutting edge, providing a greater depth of cut, higher metal removal rate, and better perpendicularity accuracy. However, the 90° principal cutting edge angle causes the cutting feed force to deviate significantly from the spindle direction, increasing the radial component of the tool force. This means increased cutting impact force on the cutting edge, potentially leading to cutting edge damage and cutting vibration.

[0003] Patent document CN102712054A discloses a cutting insert with a recessed cutting edge. The main cutting edge is interrupted at the recessed cutting edge portion by the recess formed in the main side surface, so that each recessed cutting edge portion is located between two non-recessed cutting edge portions. Each recessed cutting edge portion includes an arc-shaped middle located between two arc-shaped sides. This structure of the cutting edge can promote cutting separation on the one hand, and on the other hand, the cutting edge can withstand greater cutting forces without breaking.

[0004] In the above solution, the implementation of the original cutting edge with concave structure has improved the problem of cutting edge breakage in rough milling to a certain extent. However, there are still some shortcomings. For example, when the cutting depth is large, the radial cutting force and cutting heat on the insert are large, and the effect of the concave structure will be weakened, which may further aggravate the wear or breakage of the cutting edge, thereby affecting the accuracy of the tool and the stability of the machining. Therefore, the above problems can be largely solved by reducing the cutting resistance of the main cutting edge and reducing the cutting heat. Summary of the Invention

[0005] The purpose of this invention is to provide a multi-bladed square shoulder milling insert to solve the problems mentioned in the prior art.

[0006] A multi-bladed square shoulder milling insert is provided, comprising:

[0007] The blade body includes an upper surface, a lower bottom surface, a side surface, and a macroscopic main cutting edge. The macroscopic main cutting edge is formed between the upper surface and the side surface. The side surface forms several inwardly recessed grooves along its length and divides the macroscopic main cutting edge into several sub-cutting edges through the grooves.

[0008] The macroscopic main cutting edge is based on the bottom surface. The line connecting the highest and lowest points in the normal direction of the bottom surface is the main inclination line. The main inclination line and the bottom surface form a macroscopic inclination angle A, and A is 13° to 17°.

[0009] The sub-cutting edge forms an independent inclination angle α with the lower bottom surface, and α is 3° to 7°.

[0010] As a further embodiment of the present invention: the macroscopic tilt angle A9 is 14° to 16°.

[0011] As a further embodiment of the present invention: the macroscopic tilt angle A9 is 14.5° to 15.5°.

[0012] As a further embodiment of the present invention: the macroscopic tilt angle A9 is 15°.

[0013] As a further embodiment of the present invention: the independent tilt angle α is 4° to 6°.

[0014] As a further embodiment of the present invention: the independent tilt angle α is 4.5° to 5.5°.

[0015] As a further embodiment of the present invention: the independent tilt angle α is 5°.

[0016] As a further embodiment of the present invention: in the direction extending from the principal inclination line towards the lower bottom surface, the distance between several sub-cutting edges and the lower bottom surface decreases sequentially. This structure is to prevent a certain sub-cutting edge from protruding and causing the relative tool tip to contact the machined surface first or too quickly, thereby preventing the sub-cutting edge from breaking due to insufficient cutting force and a sharp increase in radial resistance.

[0017] As a further embodiment of the present invention: the sub-cutting edge forms an angle of γ degrees with the adjacent groove wall, and γ > 90°. The obtuse angle between the sub-cutting edge and the adjacent groove wall can strengthen the structural strength, improve the overall anti-splitting performance of the sub-cutting edge, and improve the durability of the cutting tool.

[0018] As a further embodiment of the present invention: the end of the side surface near the bottom surface is recessed inward, forming a side positioning surface, a clearance angle surface, and a clearance surface on the side surface, respectively. The sub-cutting edge is formed between the clearance angle surface and the upper surface. The side positioning surface provides lateral positioning for the insert body at the assembly end, ensuring the positioning accuracy of the insert body. At the cutting end, it facilitates chip removal and reduces chip scratches on the side surface. The clearance angle surface increases the thickness of each sub-cutting edge, improving the strength of the sub-cutting edge. The clearance surface serves as a structural transition between the side positioning surface and the clearance angle surface.

[0019] As a further embodiment of the present invention: a screw hole extends between the upper surface and the lower bottom surface, and the principal inclination angles of the two macroscopic main cutting edges on the blade body are arranged rotationally symmetrically with respect to the central axis of the screw hole. Since the macroscopic inclination angles of the principal inclination angles are the same, this structure allows the two macroscopic main cutting edges on a single blade body to be used interchangeably without affecting the reduction effect on the radial resistance of the blade.

[0020] As a further embodiment of the present invention, it also includes a tool holder and a locking screw. The end of the tool holder has several circumferential grooves, and countersunk holes for screws are formed within these grooves. Each groove is fixed to a single blade through the engagement of the screw hole, the countersunk hole, and the locking screw. The blade body can be rotated around the screw hole at a horizontal angle to switch the macroscopic main cutting edge for operation, and then fixed using the locking screw and countersunk hole. This facilitates replacement and fixation, and allows for the reuse of a single blade.

[0021] As a further embodiment of the present invention: the number of grooves on the tool holder is even, and the grooves are evenly arranged along the circumference of the tool holder. On the axial rotation plane coinciding with the central axis of the tool holder, two macroscopic main cutting edges arranged opposite each other on the tool holder and located outside the insert body respectively form cutting trajectory projections on the axial rotation plane. The cutting trajectory projections of the groove portions on the two macroscopic main cutting edges are arranged sequentially at intervals. When the tool holder drives the insert body to rotate, the two opposite macroscopic main cutting edges avoid each other due to the groove portions, ensuring that each sub-cutting edge on the two macroscopic main cutting edges participates in the cutting of the material left in the groove portion. The material left in the previous groove is cut by the subsequent sub-cutting edges. Each sub-cutting edge corresponds to a single groove, improving the cutting uniformity of the cutting surface, reducing chip resistance, and lowering the probability of sub-cutting edge breakage.

[0022] As a further embodiment of the present invention: when two insert bodies are arranged opposite each other on the tool holder, after rotating the two insert bodies relative to their corresponding tool grooves and rotating them by a horizontal angle around the central axis of their corresponding screw holes, the macroscopic main cutting edges on the outer sides of the two insert bodies form cutting trajectory projections on the axial rotation plane. The cutting trajectory projections of the groove portions on the two macroscopic main cutting edges are arranged in a sequentially spaced manner. Each insert body has two macroscopic main cutting edges that can be used for cutting, and the two insert bodies form a group. The macroscopic main cutting edges of the two insert bodies can interchange positions to work, improving the utilization rate of the insert bodies.

[0023] As a further embodiment of the present invention: the upper surface is provided with a first identification point and a second identification point for identifying two macroscopic main cutting edges respectively.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0025] 1. This invention decomposes the macroscopic main cutting edge into multiple segments through grooves, forming multiple relatively independent sub-cutting edges, thereby weakening the interaction between the sub-cutting edges, reducing heat transfer during cutting, and dispersing the impact of radial resistance on the cutting edge, reducing the probability of cutting edge breakage, and further improving the service life of the cutting tool.

[0026] 2. The macroscopic rake angle of the cutting edge is greater than the independent rake angle. According to the law of force decomposition, the larger macroscopic rake angle reduces the radial resistance of the insert, which helps to suppress the cutting vibration of the tool and reduces the degree of damage to the cutting edge caused by cutting resistance. In addition, the sub-cutting edge has a smaller independent rake angle, which can achieve a larger wedge angle, improve the strength of the tool tip, and reduce the probability of tool tip breakage. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of this drawing or the prior art, 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 drawing. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0028] Figure 1 This is a perspective view of the blade provided by the present invention;

[0029] Figure 2 This is a front view of the blade provided by the present invention;

[0030] Figure 3 This is a right view of the blade provided by the present invention;

[0031] Figure 4 This is a left view of the blade provided by the present invention;

[0032] Figure 5 This is a top view of the blade provided by the present invention;

[0033] Figure 6 This is a cross-sectional view of the blade provided by the present invention;

[0034] Figure 7 This is a schematic diagram of the blade cutting state provided by the present invention;

[0035] Figure 8 This is a schematic diagram of the overlapping of the two blades provided by the present invention;

[0036] Figure 9 This is a diagram of the tool holder and tool groove provided by the present invention;

[0037] Figure 10 This is a schematic diagram of the cutting state of the tool provided by the present invention;

[0038] Figure 11 yes Figure 5 A magnified view of a portion of region F in the middle.

[0039] In the diagram: 1. Blade body; 2. Macroscopic main cutting edge; 3. Groove; 4. Sub-cutting edge; 5. Upper surface; 6. Lower bottom surface; 7. Side surface; 8. End surface; 9. Finishing edge; 10. Clearance groove; 11. Secondary cutting edge; 12. First macroscopic main cutting edge; 13. Second macroscopic main cutting edge; 14. Blade tip; 15. First sub-cutting edge; 16. Second sub-cutting edge; 17. Third sub-cutting edge; 18. First groove; 19. Second groove; 21. Clearance angle surface; 22. Clearance surface; 24. Corner; 25. Fourth sub-cutting edge; 26. Fifth sub-cutting edge; 27. Sixth sub-cutting edge; 28. Third groove; 29. ​​Fourth groove; 31. End positioning surface; 32. Side positioning surface; 34. First rear corner surface; 35. Second rear corner surface; 36. Third rear corner surface; 37. First clearance surface; 38. Second clearance surface; 39. Third clearance surface; 44. Fourth rear corner surface; 45. Fifth rear corner surface; 46. Sixth rear corner surface; 47. Fourth clearance surface; 48. Fifth clearance surface; 49. Sixth clearance surface; 50. Finishing edge rear corner surface; 55. First identification point; 56. Second identification point; 60. Screw hole; 70. Locking screw; 72. End support surface; 73. Bottom support surface; 74. Side support surface; 75. Screw countersunk hole; 80. Tool holder; 81. Tool groove; 90. Tool; 100. Side machined surface; 200. Bottom machined surface. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be described and illustrated below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. All other embodiments obtained by those skilled in the art based on the embodiments provided by this invention without inventive effort are within the scope of protection of this invention.

[0041] Obviously, the accompanying drawings described below are merely some examples or embodiments of the present invention. Those skilled in the art can apply the present invention to other similar scenarios based on these drawings without any inventive effort. Furthermore, it is understood that although the efforts made in this development process may be complex and lengthy, for those skilled in the art related to the content disclosed in this invention, modifications to design, manufacturing, or production based on the technical content disclosed in this invention are merely conventional technical means and should not be construed as insufficient disclosure of the present invention.

[0042] However, there may be instances where unnecessary detailed descriptions are omitted. For example, detailed descriptions of well-known matters or repetitive descriptions of essentially the same structures may be omitted. This is to avoid making the following description unnecessarily lengthy and to facilitate understanding by those skilled in the art. Furthermore, the accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the invention and are not intended to limit the subject matter of the claims.

[0043] Please see Figures 1-4 As shown, the multi-blade square shoulder milling insert of this embodiment includes an insert body 1, which consists of an upper surface 5, a lower bottom surface 6, a side surface 7, and a macroscopic main cutting edge 2. The macroscopic main cutting edge 2 is formed between the upper surface 5 and the side surface 7. The side surface 7 has several inwardly recessed grooves 3 along its length, which divide the macroscopic main cutting edge 2 into several sub-cutting edges 4. The macroscopic main cutting edge 2 is based on the lower bottom surface 6. The line connecting the highest and lowest points in the normal direction of the lower bottom surface 6 is the main inclination line. The main inclination line and the lower bottom surface 6 form a macroscopic inclination angle A, which is 13° to 17°. The lines of the sub-cutting edges 4 form independent inclination angles α with the lower bottom surface 6, which are 3° to 7°.

[0044] Please see Figure 2 and Figure 9 As shown, the milling insert also includes a tool holder 80 and a locking screw 70. After the insert body 1 is assembled with the locking screw 70 and the tool holder 80, a cutting tool 90 is formed. The cutting end of the tool holder 80 has a groove 81 for mounting the insert body 1. Multiple grooves 81 can be provided at the cutting end of the tool holder 80. The groove 81 includes an end support surface 72, a side support surface 74, a bottom support surface 73, and a countersunk hole 75. The lower bottom surface 6 serves as a positioning base surface, cooperating with the bottom support surface 73 of the groove 81 to maintain good positioning accuracy for the insert body 1. The bottom support surface 73 provides sufficient bottom support force for the insert body 1. The tool 90 is assembled by placing the locking screw 70 in the screw hole 60 of the insert body 1, passing it through the countersunk hole 75 to fix the insert body 1 in the groove 81. The tool 90 can then rotate at high speed around its rotation center O for efficient machining of the workpiece.

[0045] In one specific embodiment, please refer to Figure 1 and Figure 2 As shown, the principal inclination lines of the macroscopic main cutting edge 2 are arranged rotationally symmetrically with respect to the central axis of the screw hole 60, forming the first macroscopic main cutting edge 12 and the second macroscopic main cutting edge 13 respectively. It should be noted that the above structure indicates that the principal inclination lines of the two macroscopic main cutting edges 2 have the same inclination angle with respect to the lower bottom surface 6, but does not indicate that the structure and arrangement of the individual sub-cutting edges 4 in the two macroscopic main cutting edges 2 are arranged rotationally symmetrically.

[0046] Please see Figures 1-4 , Figure 6 , Figure 9 and Figure 11 As shown, the end of the side surface 7 near the bottom surface 6 is recessed inward, forming a side positioning surface 32, a rear corner surface 21, and a gap surface 22. Specifically, the side surface 7 includes a side positioning surface 32, a first rear corner surface 34, a first gap surface 37, a second rear corner surface 35, a second gap surface 38, a third rear corner surface 36, a third gap surface 39, a fourth rear corner surface 44, a fourth gap surface 47, a fifth rear corner surface 45, a fifth gap surface 48, a sixth rear corner surface 46, and a sixth gap surface 49.

[0047] The side positioning surface 32 cooperates with the side support surface 74 of the tool groove to provide lateral positioning for the insert body 1. The side support surface 74 provides lateral support force to the insert body 1. The side positioning surface 32 is recessed into the insert body 1 relative to the first clearance angle surface 34, the second clearance angle surface 35, the third clearance angle surface 36, the fourth clearance angle surface 44, the fifth clearance angle surface 45, and the sixth clearance angle surface 46, to prevent damage to the side positioning surface 32 during the cutting process and ensure the positioning accuracy of the insert body 1. The width value H8 of any clearance angle surface 21 and the arc value R of any clearance surface 22 are taken to be as large as possible to reduce stress concentration, reduce the generation of cracks during production, provide sufficient cutting support force for the cutting edge, and reduce the possibility of cutting edge collapse. The angle γ formed by any sub-cutting edge 4 and the adjacent groove wall 3 is an obtuse angle. The arc r inside the groove 3 is taken to be as large as possible to strengthen the structural strength, improve the overall anti-splitting performance of the sub-cutting edge 4, and improve the durability of the insert.

[0048] Please see Figure 1 , Figure 2 and Figure 9 As shown, the end surface 8 has an end positioning surface 31, a clearance groove 10, and a finishing edge relief angle surface 50. The end positioning surface 31 cooperates with the end support surface 72 of the tool groove 81 to provide end face positioning for the insert body 1, and the end support surface 72 provides end face support force for the insert body 1. The clearance groove 10 is located between the end positioning surface 31 and the finishing edge relief angle surface 50 and is recessed inward relative to the insert body 1. The finishing edge 9 is formed between the finishing edge relief angle surface 50 and the upper surface 5. The finishing edge 9 plays a finishing role on the machined surface, which can improve the surface finish and improve the machining quality of the workpiece. The finishing edge relief angle surface 50 provides sufficient cutting support force for the finishing edge 9. The chips generated during finishing by the finishing edge 9 can be discharged through the clearance groove 10. The secondary cutting edge 11 is formed between the end positioning surface 31 and the upper surface 5. The secondary cutting edge 11 is connected to the macro main cutting edge 2 through a straight transition corner 24.

[0049] Please see Figure 1As shown, the screw hole 60 is located at the geometric center S of the insert body 1 and extends through the insert body 1. The first macroscopic main cutting edge 12 and the second macroscopic main cutting edge 13 are connected to the finishing edge 9 by a tool tip 14 with a rounded transition. The tool tip 14 is the area where cutting force and cutting heat are concentrated. The first macroscopic main cutting edge 12 forms a first sub-cutting edge 15, a second sub-cutting edge 16, and a third sub-cutting edge 17 through two grooves 3. The second macroscopic main cutting edge 13 forms a fourth sub-cutting edge 25, a fifth sub-cutting edge 26, and a sixth sub-cutting edge 27 through two grooves 3. Any sub-cutting edge 4 of any macroscopic main cutting edge 2 can participate in cutting independently or all of them can participate in cutting depending on the cutting depth. This increases the strength of the tool tip 14 when cutting at shallow depths and reduces the cutting resistance when cutting at deep depths, thus further expanding the application range of the insert body 1.

[0050] Please see Figure 1 , Figure 3 and Figure 4 As shown, the first sub-cutting edge 15 and the fourth sub-cutting edge 25 are adjacent to the tool tip 14. The first sub-cutting edge 15, the fourth sub-cutting edge 25 and the finishing edge rake face 50 form a wedge angle β. The larger the wedge angle β, the better the strength of the tool tip 14 and the higher the chip resistance. However, if the wedge angle β is too large, it will affect the chip removal effect. Therefore, β is set at 60° to 70°. The third sub-cutting edge 17 and the sixth sub-cutting edge 27 are adjacent to the corner 24. The second sub-cutting edge 16 is located between the first sub-cutting edge 15 and the third sub-cutting edge 17, and the fifth sub-cutting edge 26 is located between the fourth sub-cutting edge 25 and the sixth sub-cutting edge 27.

[0051] Please see Figure 1 , Figure 2 and Figure 5 As shown, the lengths of the sub-cutting edges 4 included in the first macroscopic main cutting edge 12 and the second macroscopic main cutting edge 13 are not equal. The lengths L1 of the first sub-cutting edge 15, L2 of the second sub-cutting edge 16, and L3 of the third sub-cutting edge 17 decrease sequentially from the tool tip 14 to the corner 24, i.e., L1 > L2 > L3. The lengths L4 of the fourth sub-cutting edge 25, L5 of the fifth sub-cutting edge 26, and L6 of the sixth sub-cutting edge 27 increase sequentially from the tool tip 14 to the corner 24, i.e., L4 < L5 < L6. In this scheme, L1 = L6, L2 = L5, and L3 = L4 are preferred.

[0052] Please see Figure 1 , Figure 3 and Figure 4As shown, in the direction extending from the principal inclination line towards the lower bottom surface 6, the distance between several sub-cutting edges 4 and the lower bottom surface 6 decreases sequentially. The sub-cutting edges 4 included in the first macroscopic principal cutting edge 12 and the second macroscopic principal cutting edge 13 have positional differences in the direction of their respective side surfaces 7, i.e., H1≠H2≠H3, H4≠H5≠H6. The first sub-cutting edge 15, the second sub-cutting edge 16, and the third sub-cutting edge 17 sequentially approach the lower bottom surface 6, i.e., H1>H2>H3, while the sixth sub-cutting edge 27, the fifth sub-cutting edge 26, and the fourth sub-cutting edge 25 sequentially move away from the lower bottom surface 6, i.e., H6<H5<H4.

[0053] The macroscopic inclination angle A9 formed by the first macroscopic main cutting edge 12 and the macroscopic inclination angle A8 formed by the second macroscopic main cutting edge 13 are equal, i.e., A9 = A8, preferably A = 15°. The independent inclination angles α formed by any sub-cutting edge 4 are equal, i.e., α1 = α2 = α3 = α4 = α5 = α6, preferably α = 5°. The macroscopic inclination angle is greater than the independent inclination angle, i.e., A > α. According to the force decomposition rule, the larger macroscopic inclination angle reduces the radial resistance, which plays a certain role in suppressing the cutting vibration of the cutting tool 90, reducing the degree of damage to the macroscopic main cutting edge 2 caused by the cutting resistance. Furthermore, the sub-cutting edge 4 adjacent to the tool tip 14 has a smaller independent inclination angle, which can achieve a larger wedge angle, improve the strength of the tool tip 14, and reduce the probability of tool tip 14 breakage.

[0054] Please see Figure 1 and Figure 5 As shown, the side surface 7 includes a first groove 18, a second groove 19, a third groove 28, and a fourth groove 29. Any groove 3 is recessed into the insert body 1. The first sub-cutting edge 15 and the second sub-cutting edge 16 are interrupted by the first groove 18; the second sub-cutting edge 16 and the third sub-cutting edge 17 are interrupted by the second groove 19; the fourth sub-cutting edge 25 and the fifth sub-cutting edge 26 are interrupted by the third groove 28; and the fifth sub-cutting edge 26 and the sixth sub-cutting edge 27 are interrupted by the fourth groove 29. The interrupted sub-cutting edges 4 form a relatively independent cutting system, which weakens the interaction between the sub-cutting edges 4 during cutting, disperses the impact of radial resistance on the cutting edge, reduces heat transfer during cutting, effectively protects the cutting edge, and further improves the service life of the insert.

[0055] Please see his 1. Figure 7 , Figure 8 , Figure 9 and Figure 10As shown, in the application scenario, when the two blade bodies 1 are arranged opposite each other on the tool holder 80, after rotating the two blade bodies 1 relative to the corresponding tool groove 81 and rotating them by a horizontal angle around the central axis of the corresponding screw hole 60, the macroscopic main cutting edges 2 on the outer sides of the two blade bodies 1 form cutting trajectory projections on the axial rotation plane, and the cutting trajectory projections of the grooves 3 on the two macroscopic main cutting edges 2 are arranged in a sequentially spaced manner. In a specific embodiment, the first sub-cutting edge 15, the second sub-cutting edge 16, the fifth sub-cutting edge 26, and the sixth sub-cutting edge 27 are rotated by a horizontal angle around the geometric center S of the blade body 1 to cover the third groove 28, the fourth groove 29, the first groove 18, and the second groove 19, respectively.

[0056] With this setup, when the tool holder 80 drives the insert body 1 to rotate, the two opposing macroscopic main cutting edges 2 avoid each other due to the grooves 3, ensuring that each sub-cutting edge 4 on the two macroscopic main cutting edges 2 participates in the cutting of the material left in the grooves 3. The material left in the previous grooves 3 is cut by the subsequent sub-cutting edges 4. Each sub-cutting edge 4 corresponds to a single groove 3, improving the cutting uniformity of the cutting surface, reducing chip resistance, and lowering the probability of sub-cutting edge breakage.

[0057] When installing the insert body 1, it is important to note that it has a first identification point 55 and a second identification point 56. If the first cutting groove 81 uses the cutting tip 14 located at the first identification point 55, then the next cutting groove 81 uses the cutting tip 14 located at the second identification point 56. Using a tool holder 80 with an even number of cutting grooves 81, and so on in staggered fashion, the two macroscopic main cutting edges 2 participate in cutting intermittently, achieving interference fit between the sub-cutting edges 4. Besides maintaining the surface finish of the bottom machined surface 200 of the workpiece, this also ensures the integrity of the side machined surface 100 of the workpiece during high-efficiency machining with large depths of cut and large feed rates.

[0058] It should be noted that the present invention is not limited to the above-described embodiments. The above embodiments are merely examples, and any embodiments that have the same structure and perform the same effects as the technical concept within the scope of the present invention are included within the scope of the present invention. Furthermore, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways of constructing by combining some of the constituent elements of the embodiments, without departing from the spirit of the present invention, are also included within the scope of the present invention.

Claims

1. A multi-bladed square shoulder milling insert, characterized in that, include: The blade body (1) includes an upper surface (5), a lower bottom surface (6), a side surface (7) and at least one macro main cutting edge (2), the macro main cutting edge (2) being formed between the upper surface (5) and the side surface (7), the side surface (7) having a plurality of inwardly recessed grooves (3) along the length direction and dividing the macro main cutting edge (2) into a plurality of sub-cutting edges (4) through the grooves (3); The macroscopic main cutting edge (2) is based on the bottom surface (6). The line connecting the highest and lowest points in the normal direction of the bottom surface (6) is the main inclination line. The macroscopic inclination angle A is formed between the main inclination line and the bottom surface (6), and A is 13°~17°. The sub-cutting edge (4) forms an independent inclination angle α with the lower bottom surface (6), and α is 3°~7°; A screw hole (60) runs through the upper surface (5) and the lower bottom surface (6). The principal inclination lines of the two macroscopic main cutting edges (2) on the blade body (1) are arranged in a rotationally symmetrical manner relative to the central axis of the screw hole (60). It also includes a blade holder (80) and a locking screw (70). The end of the blade holder (80) is formed with a plurality of blade grooves (81) along the circumferential direction. A screw countersunk hole (75) is formed in the blade groove (81). Each blade groove (81) is fixed to a single blade by the cooperation of the screw hole (60), the screw countersunk hole (75) and the locking screw (70). The number of the cutting grooves (81) on the tool holder (80) is even, and the cutting grooves (81) are evenly arranged along the circumference of the tool holder (80). On the axial rotation plane that coincides with the central axis of the tool holder (80), the two macroscopic main cutting edges (2) arranged opposite to each other on the tool holder (80) and located outside the blade body (1) respectively form cutting trajectory projections on the axial rotation plane. The cutting trajectory projections of the grooves (3) on the two macroscopic main cutting edges (2) are arranged in a sequentially spaced manner.

2. The multi-blade square shoulder milling insert according to claim 1, characterized in that, In the direction of extension from the principal inclination line toward the lower bottom surface (6), the distance between several sub-cutting edges (4) and the lower bottom surface (6) decreases sequentially.

3. A multi-bladed square shoulder milling insert according to claim 1, characterized in that, The sub-cutting edge (4) forms an angle of γ degrees with the adjacent groove wall (3), and γ > 90°.

4. A multi-bladed square shoulder milling insert according to claim 1, characterized in that, The side surface (7) is recessed inward at one end near the bottom surface (6) so that the side surface (7) forms a side positioning surface (32), a rear corner surface (21) and a gap surface (22) respectively. The sub-cutting edge (4) is formed between the rear corner surface (21) and the upper surface (5).

5. A multi-bladed square shoulder milling insert according to claim 1, characterized in that, When the two blade bodies (1) are arranged opposite each other on the tool holder (80), the two blade bodies (1) are rotated relative to the corresponding tool groove (81) and rotated by a horizontal angle around the central axis of the corresponding screw hole (60). The macroscopic main cutting edge (2) on the outer side of the two blade bodies (1) forms a cutting trajectory projection on the axial rotation plane. The cutting trajectory projections of the groove (3) on the two macroscopic main cutting edge (2) are arranged in a sequentially spaced manner.

6. A multi-bladed square shoulder milling insert according to claim 1, characterized in that, The upper surface (5) is provided with a first identification point (55) and a second identification point (56), which are used to identify the two macroscopic main cutting edges (2).

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