A cutting insert

Abstract

This invention relates to the field of cutting tool technology and discloses a cutting insert. A first rake face gives the cutting insert a cutting edge width at its tip, improving its strength. Along the direction away from the front cutting edge, the direction of the cutting force on the chips generated during cutting changes with the chip-reversing structure. The closer to the center plane, the smaller the cutting force and the smaller the upward force on the chip. This causes the chip to deform, forming a structure with a concave center and gradually convex sides, i.e., a low center and high sides. This increases chip rigidity while reducing chip width, preventing scraping of the machined surface and improving the surface quality on both sides. Setting L1 > L2 ensures that the chip-reversing structure extends upward from the tangential position along the direction away from the front cutting edge, avoiding the large cutting force brought by the upward extension of the chip-reversing structure, thus meeting the machining requirements of lower cutting forces. It also facilitates chip deformation and smooth chip removal, improving cutting rigidity.

Description

Technical Field

[0001] This invention relates to the field of cutting tool technology, and more particularly to a cutting insert. Background Technology

[0002] The cutting edge of a flat-end insert is a straight edge. During machining, the chip wrapping effect is worse compared to that of a parting groove insert, and the concave effect is relatively less pronounced. The resulting chip width is approximately the same as the width of the insert. Considering the vibration during machining, chips with a width close to the insert width will scrape against the machined surfaces on both sides of the workpiece, thus affecting the surface roughness of the workpiece.

[0003] To address this, existing technologies propose incorporating a chip-resistant wall structure on the upper surface of the cutting insert. This causes the generated chips to undergo wavy deformation, thereby reducing chip width. Specifically, a rake face extends from the cutting edge to the lower surface in a direction away from the cutting edge, forming the chip-resistant wall structure. The rake face has a positive rake angle, while the chip-resistant structure has a negative rake angle, creating a cutting effect similar to a curved cutting edge. When this cutting insert is used to cut a workpiece, the generated chips will experience an upward force on the chip-resistant wall structure with the negative rake angle, causing the chips to deform upwards. At the positive rake angle, the chips deform downwards, thus reducing chip width.

[0004] However, the presence of a chip-resistant wall structure with a negative rake angle increases the cutting force when the cutting insert cuts the workpiece. When the machining conditions require a lower cutting force, the cutting insert with the aforementioned chip-resistant wall structure with a negative rake angle clearly cannot meet the requirements. Therefore, there is an urgent need for a cutting insert to solve the above-mentioned technical problems. Summary of the Invention

[0005] The purpose of this invention is to provide a cutting blade that can deform the chip, thereby reducing the chip width and the cutting force of the blade.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] A cutting insert includes an upper surface and a lower surface arranged opposite each other along the Z direction, a longitudinal side surface connecting the upper surface and the lower surface, and two transverse side surfaces connecting the longitudinal side surfaces and the upper surface and arranged opposite each other along the Y direction; the upper surface and the longitudinal side surfaces intersect to form a front cutting edge; the front cutting edge extends in a direction away from the front cutting edge toward the side where the lower surface is located to form a first rake face;

[0008] The cutting insert also includes two anti-chip structures disposed on the upper surface. The two anti-chip structures are located on both sides of the central plane of the cutting insert, and the central plane is perpendicular to the Y direction. One end of the anti-chip structure near the front cutting edge is connected to the first rake face, and the other end extends towards the side of the upper surface in a direction away from the longitudinal side.

[0009] From the direction of the cross-cutting edge near the central plane, the anti-chip structure includes a first outer anti-chip surface, a second outer anti-chip surface, and an inner anti-chip surface that are smoothly connected in sequence. The first outer anti-chip surface and the inner anti-chip surface both extend towards the side where the lower surface is located in the direction near the central plane, and the second outer anti-chip surface extends towards the side where the upper surface is located in the direction near the central plane.

[0010] The length of the cross section of the first rake face in the central plane along the X direction is L1. One end of the anti-chip structure is tangent to the first rake face, and the distance between the tangent position and the front cutting edge in the X direction is L2, where L1 > L2. The X direction, the Y direction, and the Z direction are perpendicular to each other.

[0011] As a preferred technical solution for the above-mentioned cutting insert, 0.08mm≤L1≤0.35mm, 0.05mm≤L2≤0.3mm.

[0012] As a preferred technical solution for the above-mentioned cutting insert, the intersection line of the inner chip-reversing surface and the preset cross section perpendicular to the Y direction is the inner chip-reversing cross section curve. The closer the inner chip-reversing cross section curve is to the center plane, the smaller the rate of curvature change of the inner chip-reversing cross section curve.

[0013] As a preferred technical solution of the above-mentioned cutting insert, the intersection line of the first outer anti-chip surface and the inner anti-chip surface is an intersection curve. Along the direction away from the front cutting edge, the intersection curve first extends to the side where the upper surface is located through an arc curve to a preset highest point K, and then extends from the preset highest point K to the side where the lower surface is located.

[0014] The distance between the preset highest point K and the front cutting edge in the X direction is L3, and the distance between the preset highest point K and the front cutting edge in the Z direction is H1, where 0.5mm≤L3≤2.5mm and 0.2mm≤H1≤0.6mm.

[0015] As a preferred technical solution of the above-mentioned cutting insert, the intersection line of the first outer chip-reversing surface and the first preset plane perpendicular to the X direction includes an outer chip-reversing straight line segment, and the included angle between the outer chip-reversing straight line segment and the second preset plane perpendicular to the Z direction is β2, 0°≤β2≤5°;

[0016] And / or, the first rake face is a plane, and the angle between the first rake face and the second preset plane perpendicular to the Z direction is β1, 5°≤β1≤10°;

[0017] And / or, the distance between the intersecting curves and the transverse cutting edge located on the same side of the central plane in the Y direction is L4, 0.1mm≤L4≤0.7mm.

[0018] As a preferred technical solution of the above-mentioned cutting insert, the upper surface is provided with a first chip groove, and the first chip groove is smoothly connected to the first rake face and the inner anti-chip surfaces of the two anti-chip structures;

[0019] The distance between the tangent positions of the two anti-chip structures in the Y direction is L5, where 0.5mm≤L5≤3.5mm.

[0020] As a preferred technical solution of the above-mentioned cutting insert, the upper surface is provided with a second chip groove, the first chip groove is located between the second chip groove and the first rake face in the X direction, and the second chip groove is connected to the inner anti-chip surfaces of the two anti-chip structures.

[0021] As a preferred technical solution of the above-mentioned cutting insert, the projection of one end of the anti-chip structure connected to the first rake face in the preset projection plane extends along a preset straight line, and the preset straight line gradually approaches the second chip groove in a direction away from the front cutting edge; the second chip groove is located between the preset straight lines of the two anti-chip structures.

[0022] The angle between the preset straight line and the central plane is β3, where 3°≤β3≤10°, and the preset projection plane is perpendicular to the Z direction.

[0023] As a preferred technical solution of the above-mentioned cutting insert, a protrusion is provided on the inner chip-reversing surface, and the circumferential edge of the protrusion is smoothly connected to the inner chip-reversing surface; the intersecting curve intersects with the third preset plane at point Q, and point Q is closer to the upper surface than the intersection line of the protrusion and the third preset plane, and the third preset plane is perpendicular to the X direction.

[0024] As a preferred technical solution of the above-mentioned cutting insert, the first rake face and the first chip groove are smoothly connected by an arc. The straight line where the first rake face intersects with the central plane is called the rake face straight line. The point where the end of the first chip groove connected with the arc intersects with the central plane is point P. The tangent line of the first chip groove passing through point P and located in the central plane is called the groove tangent line.

[0025] The straight line of the rake face intersects the groove tangent at point J, the front cutting edge intersects the center plane at point O, and the distance between point O and point J in the X direction is L1; the angle between the groove tangent and the second preset plane perpendicular to the Z direction is β4, 15°≤β4≤35°.

[0026] The beneficial effects of this invention are as follows: The cutting insert provided by this invention has a first rake face formed by the front cutting edge extending downwards along a direction away from the front cutting edge to the side where the lower surface is located. This allows the cutting insert to have a cutting edge width at the front end, ensuring the sharpness of the cutting insert while improving its strength. The chip-reversing structure extends from the transverse cutting edge towards the center plane, first to the side where the lower surface is located, then to the side where the upper surface is located, and finally back to the side where the lower surface is located. During the cutting process, along the direction away from the front cutting edge, the direction of the cutting force on the chips generated during the cutting process changes with the chip-reversing structure. The closer to the center plane, the smaller the cutting force and the smaller the upward force on the chips. This causes the chips to deform, forming a structure with a concave lower surface in the middle and gradually convex upper surface on both sides. That is, chips that are low in the middle and high on both sides, increasing chip rigidity while reducing chip width, avoiding scraping the machined surface, and improving the surface quality on both sides.

[0027] The projection of the first rake face onto the center plane has a length L1 along the X direction. One end of the chip-removing structure is tangent to the first rake face, and the distance between the tangent position and the front cutting edge in the X direction is L2, where L1 > L2. This configuration allows the chip-removing structure to extend upwards from the tangent position L2 on the first rake face away from the front cutting edge, avoiding the increased cutting force that would result from its upward extension. While the chip-removing structure effectively reduces cutting force to meet operational requirements, it also promotes chip deformation, improves cutting rigidity, and facilitates smooth chip removal. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the content of the embodiments of the present invention and these drawings without creative effort.

[0029] Figure 1 This is a schematic diagram of the structure of the cutting blade provided in an embodiment of the present invention;

[0030] Figure 2 This is a partial top view of the cutting blade provided in an embodiment of the present invention;

[0031] Figure 3 yes Figure 2Sectional view along axis AA;

[0032] Figure 4 yes Figure 3 A magnified view of a portion of point I in the middle;

[0033] Figure 5 yes Figure 1 A magnified view of a portion of point F in the middle;

[0034] Figure 6 yes Figure 2 Sectional view along the BB direction;

[0035] Figure 7 yes Figure 6 A magnified view of a portion of point E in the middle;

[0036] Figure 8 yes Figure 2 Sectional view along the CC direction.

[0037] In the picture:

[0038] 1. Front cutting edge; 2. Cross cutting edge; 3. First rake face; 4. Chip reversal structure; 41. Inner chip reversal surface; 411. Inner chip reversal arc segment; 42. Second outer chip reversal surface; 421. Outer chip reversal arc segment; 43. Second rake face; 431. Rake face arc segment; 44. First outer chip reversal surface; 441. Outer chip reversal straight segment; 5. Protrusion; 6. First chip groove; 7. Second chip groove;

[0039] 100, upper surface; 200, lower surface; 300, longitudinal side surface; 400, transverse side surface; 500, center plane; 600, first preset plane; 700, second preset plane; 800, third preset plane; 900, intersecting curve. Detailed Implementation

[0040] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0041] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" 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 invention based on the specific circumstances.

[0042] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0043] In the description of this embodiment, the terms "upper," "lower," "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0044] like Figures 1 to 5 As shown, an embodiment of the invention provides a cutting insert, including an upper surface 100 and a lower surface 200 arranged opposite each other along the Z direction, a longitudinal side surface 300 connecting the upper surface 100 and the lower surface 200 and arranged along the X direction, and two transverse side surfaces 400 connecting the longitudinal side surfaces 300 and the upper surface 100 and arranged opposite each other along the Y direction. The upper surface 100 and the longitudinal side surface 300 intersect to form a front cutting edge 1, and the upper surface 100 and the transverse side surfaces 400 intersect to form a transverse cutting edge 2. The front cutting edge 1 extends downward along a direction away from the front cutting edge 1 to the side where the lower surface 200 is located to form a first rake face 3. The first rake face 3 can give the cutting insert a cutting edge width at the tip, which can improve the strength of the cutting insert while maintaining its sharpness.

[0045] The cutting insert also includes two anti-chip structures 4 disposed on the upper surface 100. The two anti-chip structures 4 are located on both sides of the central plane 500 of the cutting insert, which is perpendicular to the Y direction. One end of the anti-chip structure 4 near the front cutting edge 1 is in contact with the first rake face 3, and the other end extends upward to the side of the upper surface 100 in a direction away from the longitudinal side 300, which is conducive to forming curled chips. For example, the two anti-chip structures 4 are symmetrically arranged about the central plane 500.

[0046] From the direction of the cross-cutting edge 2 near the central plane 500, the anti-chip structure 4 includes a first outer anti-chip surface 44, a second outer anti-chip surface 42 and an inner anti-chip surface 41 that are smoothly connected in sequence. The first outer anti-chip surface 44 and the inner anti-chip surface 41 both extend to the side of the lower surface 200 in the direction near the central plane 500, and the second outer anti-chip surface 42 extends to the side of the upper surface 100 in the direction near the central plane 500.

[0047] During the cutting process, along the direction away from the front cutting edge 1, the direction of the cutting force on the chips generated during the cutting process changes with the anti-chip structure 4. The closer to the center plane 500, the smaller the cutting force and the smaller the upward force on the chips. This causes the chips to deform and form a structure with a concave lower surface 200 in the middle and a gradually convex upper surface 100 on both sides. That is, chips that are low in the middle and high on both sides increase the rigidity of the chips and reduce the width of the chips, avoid scraping the machined surface, and improve the surface quality on both sides.

[0048] The length of the cross section of the first rake face 3 in the central plane 500 along the X direction is L1. One end of the chip-removing structure 4 is tangent to the first rake face 3, and the distance between the tangent position and the front cutting edge 1 in the X direction is L2, where L1 > L2. The X, Y, and Z directions are perpendicular to each other. This configuration allows the chip-removing structure 4 to extend upwards from the tangent position L2 on the first rake face 3 to the front cutting edge 1 in a direction away from the front cutting edge 1, avoiding the upward extension of the chip-removing structure 4 which would bring greater cutting force. Even though the chip-removing structure 4 has the function of reducing cutting force to meet the usage requirements, it also facilitates chip deformation, improves cutting rigidity, and promotes smooth chip removal.

[0049] In some embodiments, 0.08mm≤L1≤0.35mm, 0.05mm≤L2≤0.3mm. This ensures that the cutting insert has good cutting strength while also maintaining a certain level of sharpness.

[0050] It should be noted that L1 can be set according to the cutting width, and different cutting widths require different L1 values. L1 can be selected from any value between 0.08mm and 0.35mm, such as any one of 0.08mm, 0.09mm, 0.10mm, 0.11mm, 0.12mm, 0.13mm, 0.14mm, 0.15mm, 0.16mm, 0.17mm, 0.18mm, 0.19mm, 0.20mm, 0.21mm, 0.22mm, 0.23mm, 0.24mm, 0.25mm, 0.26mm, 0.27mm, 0.28mm, 0.29mm, 0.30mm, 0.31mm, 0.32mm, 0.33mm, 0.34mm, and 0.35mm. L2 can be selected from any value between 0.05mm and 0.3mm, such as any one of 0.05mm, 0.06mm, 0.07mm, 0.08mm, 0.09mm, 0.10mm, 0.11mm, 0.12mm, 0.13mm, 0.14mm, 0.15mm, 0.16mm, 0.17mm, 0.18mm, 0.19mm, 0.20mm, 0.21mm, 0.22mm, 0.23mm, 0.24mm, 0.25mm, 0.26mm, 0.27mm, 0.28mm, 0.29mm, and 0.30mm.

[0051] In some embodiments, such as Figure 4 As shown, the intersection line between the inner chip-reversing surface 42 and the preset cross-section perpendicular to the Y direction is the inner chip-reversing cross-section curve. The closer the inner chip-reversing cross-section curve is to the center plane 500, the smaller the rate of change of curvature of the inner chip-reversing cross-section curve. With this design, the closer to the second outer chip-reversing surface 42, the greater the cutting force of the second outer chip-reversing surface 42; the closer to the center plane 500, the gentler the change in cutting force of the inner chip-reversing surface 41, and the smaller the upward force on the chip. Thus, during the cutting process, the chip on the inner chip-reversing surface 41 experiences a gentler force, which is conducive to the formation of a chip shape that is low in the middle and high at both ends, thereby reducing the chip width.

[0052] In some embodiments, such as Figures 6 to 8As shown, the portion where the second outer chip-reversing surface 42 and the inner chip-reversing surface 41 are smoothly connected forms the second rake face 43. The cross-section of the second rake face 43 within the first preset plane 600 includes the rake face arc segment 431. The cross-section of the second outer chip-reversing surface 42 within the first preset plane 600 includes the outer chip-reversing arc segment 421. The cross-section of the inner chip-reversing surface 41 within the first preset plane 600 includes the inner chip-reversing arc segment 411. The first preset plane 600 is perpendicular to the X direction. From the direction of the transverse cutting edge 2 near the center plane 500, the outer chip-reversing arc segment 421, the rake face arc segment 431, and the inner chip-reversing arc segment 411 are smoothly connected in sequence. The rate of curvature change of the outer chip-reversing arc segment 421 is greater than the rate of curvature change of the inner chip-reversing arc segment 411.

[0053] The curvature change rate of the outer anti-chip arc segment 421 is greater than that of the inner anti-chip arc segment 411, making the slope change of the inner anti-chip surface 41 more gradual than that of the second outer anti-chip surface 42. Since the cutting force is smaller the closer to the center plane 500, the smaller the upward force on the chip. Thus, during the cutting process, the chip on the inner anti-chip surface 41 experiences a more gentle force, which is conducive to the formation of a chip shape that is low in the middle and high at both ends, thereby reducing the chip width.

[0054] In some embodiments, the intersection line of the second outer chip-reversing surface 42 and the inner chip-reversing surface 41 is an intersection curve 900. Along the direction away from the front cutting edge 1, the intersection curve 900 first extends through an arc curve to the side where the upper surface 100 is located to a preset highest point K, and then extends from the preset highest point K to the side where the lower surface 200 is located. The setting of the arc curve enables the chips to curl during the grooving process.

[0055] The preset distance between the highest point K and the front cutting edge 1 in the X direction is L3, and the preset distance between the highest point K and the front cutting edge 1 in the Z direction is H1, where 0.5mm≤L3≤2.5mm and 0.2mm≤H1≤0.6mm. By limiting H1 and L3, C-shaped or spring-shaped chips can be formed, and the chips can be guided to be smoothly discharged along the extension direction of the arc curve.

[0056] It should be noted that L3 can be any value between 0.5mm and 2.5mm, such as any one of 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1.0mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2.0mm, 2.1mm, 2.2mm, 2.3mm, 2.4mm, or 2.5mm. H1 can be any value between 0.2mm and 0.6mm, such as any one of 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm, 0.55mm, or 0.6mm.

[0057] In some embodiments, the distance between the intersecting lines and the transverse cutting edge 2 on the same side of the central plane 500 in the Y direction is L4, where 0.1mm ≤ L4 ≤ 0.7mm. It should be noted that L4 can be any value between 0.1mm and 0.7mm, such as any one of 0.1mm, 0.15mm, 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm, 0.55mm, 0.6mm, 0.65mm, or 0.7mm.

[0058] In some embodiments, the included angle between the first rake face 3 and the second preset plane 700 is β1, where 5°≤β1≤10°. It should be noted that β1 can be any value between 5° and 10°, such as β1 can be any one of 5°, 6°, 7°, 8°, 9°, and 10°.

[0059] In some embodiments, the intersection line of the first outer chip-removing surface 44 and the first preset plane 600 perpendicular to the X direction includes an outer chip-removing straight line segment 441, and the included angle between the outer chip-removing straight line segment 441 and the second preset plane 700 is β2, where 0° < β2 ≤ 5°. It should be noted that β2 can be any value between 0° and 5°, such as β2 can be any one of 1°, 2°, 3°, 4°, or 5°.

[0060] In some embodiments, such as Figure 2 As shown, the upper surface 100 is provided with a first chip groove 6, which smoothly connects with the rake face and the inner chip-reversing surfaces 41 of the two chip-reversing structures 4. By using the first chip groove 6 in conjunction with the inner chip-reversing surfaces 41, it is beneficial to guide the part of the chip close to the center plane 500 to become concave, reduce the chip width, and thus improve the surface quality of the workpiece.

[0061] In some embodiments, the distance between the tangent positions of the two anti-chip structures 4 in the Y direction is L5, where 0.5mm ≤ L5 ≤ 3.5mm. By setting the distance L5, it can be ensured that the first chip groove 6 has sufficient chip-holding space to achieve a better chip-holding effect.

[0062] It should be noted that L5 can be any value between 0.5mm and 3.5mm, such as any one of 0.5mm, 1.0mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2.0mm, 2.1mm, 2.2mm, 2.3mm, 2.4mm, 2.5mm, 2.6mm, 2.7mm, 2.8mm, 2.9mm, 3.0mm, 3.1mm, 3.2mm, 3.3mm, 3.4mm, and 3.5mm.

[0063] In some embodiments, such as Figure 2 As shown, the upper surface 100 is provided with a second chip groove 7, which is connected to the inner chip-reversing surfaces 41 of the two chip-reversing structures 4. The first chip groove 6 is located between the second chip groove 7 and the first rake face 3. During the chip machining process, the second chip groove 7 provides a larger space, which can be used for heat dissipation, coolant flow, and guiding the chips to be discharged smoothly.

[0064] In some embodiments, such as Figure 2 As shown, the projection of one end of the chip-removing structure 4 connected to the first rake face 3 in the preset projection plane extends along a preset straight line M. The preset straight line M gradually approaches the second chip-receiving groove 7 in a direction away from the front cutting edge 1. The second chip-receiving groove 7 is located between the preset straight lines M of the two chip-removing structures 4. The angle between the preset straight line M and the center plane 500 is β3, 3°≤β3≤10°, and the preset projection plane is perpendicular to the Z direction. With this configuration, the second chip-receiving groove 7 can work together with the chip-removing structure 4 to act on the chip, which is beneficial for forming chips that are high in the middle and low on both sides.

[0065] It should be noted that β3 can be any value between 3° and 10°, such as β3 can be any one of 3°, 4°, 5°, 6°, 7°, 8°, 9°, or 10°.

[0066] In some embodiments, such as Figure 5 and Figure 8 As shown, a protrusion 5 is provided on the inner anti-chip surface 41, and the circumferential edge of the protrusion 5 is smoothly connected to the inner anti-chip surface 41; the intersecting curve 900 intersects the third preset plane 800 at point Q, and point Q is closer to the upper surface 100 than the intersection line of the protrusion 5 and the third preset plane 800; the third preset plane 800 is perpendicular to the X direction.

[0067] During the cutting process, when the C-shaped or spring-shaped chips reach the protrusion 5, the concave chips come into contact with the protrusion 5. The protrusion 5 acts as a friction reduction point and supports the cutting process. The protrusion 5 can increase the contact area between the chips and the cutting blades, reduce the friction force on the anti-chip structures 4 on both sides, and at the same time, the protrusion 5 applies an upward force to the chips, pushing them out.

[0068] Specifically, the cross-section of the protrusion 5 within the third preset plane 800 includes a first arc segment and a second arc segment. The second arc segment is closer to the central plane 500 than the first arc segment. The center of the first arc segment points to the lateral side 400 on the same side as the first arc segment located on the central plane 500, and the center of the second arc segment points to the central plane 500.

[0069] In some embodiments, such as Figure 4 As shown, the first rake face 3 and the first chip groove 6 are smoothly connected by an arc. The straight line where the first rake face 3 intersects the central plane 500 is called the rake face straight line. The point where the end of the first chip groove 6 connected to the arc intersects the central plane 500 is point P. The tangent line of the first chip groove 6 passing through point P and located in the central plane 500 is called the groove tangent line. The rake face straight line and the groove tangent line intersect at point J. The front cutting edge 1 intersects the central plane 500 at point O. The distance between point O and point J in the X direction is L1. The angle between the groove tangent line and the second preset plane 700 perpendicular to the Z direction is β4, 15°≤β4≤35°.

[0070] The larger β4 is, the sharper the first rake face 3 is, but the lower the structural strength of the cutting insert; the smaller β4 is, the higher the structural strength of the cutting insert is, but the weaker the sharpness of the first rake face 3 is. By limiting the fit between L1 and β4, it is possible to improve the structural strength of the rake cutting edge 1 while taking into account the sharpness of the cutting insert.

[0071] It should be noted that β4 can be any value between 15° and 35°, such as β4 can be any one of 15°, 20°, 25°, 30°, or 35°.

[0072] The cutting insert provided in this embodiment of the invention can improve the strength of the cutting insert while ensuring the cutting force, and ensure that the chips can be curled and smoothly discharged, while forming a chip shape that is low in the middle and high on both sides, thereby improving chip rigidity, reducing chip width, and improving workpiece surface quality. By increasing the spacing L4, the chip space of the first chip groove 6 is increased, improving the heat dissipation capacity of the cutting insert during the machining process, and extending the service life of the cutting insert.

[0073] It should be noted that the cutting inserts provided in the embodiments of the present invention are mainly flat-headed fluted inserts, which can be single-headed inserts or double-headed inserts.

[0074] Furthermore, the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. A cutting insert, comprising an upper surface (100) and a lower surface (200) disposed opposite to each other along the Z direction, a longitudinal side surface (300) connecting the upper surface (100) and the lower surface (200), and two transverse side surfaces (400) connecting the longitudinal side surface (300) and the upper surface (100) and disposed opposite to each other along the Y direction; the upper surface (100) intersects the longitudinal side surface (300) to form a front cutting edge (1), and the upper surface (100) intersects the transverse side surface (400) to form a transverse cutting edge (2); the front cutting edge (1) extends toward the side where the lower surface (200) is located in a direction away from the front cutting edge (1) to form a first rake face (3); The cutting insert also includes two anti-chip structures (4) disposed on the upper surface (100). The two anti-chip structures (4) are located on both sides of the central plane (500) of the cutting insert, and the central plane (500) is perpendicular to the Y direction. One end of the anti-chip structure (4) near the front cutting edge (1) is connected to the first rake face (3), and the other end extends towards the side of the upper surface (100) in a direction away from the longitudinal side surface (300). Its features are, From the direction of the cross-cutting edge (2) near the central plane (500), the anti-chip structure (4) includes a first outer anti-chip surface (44), a second outer anti-chip surface (42), and an inner anti-chip surface (41) that are smoothly connected in sequence. The first outer anti-chip surface (44) and the inner anti-chip surface (41) both extend towards the side of the lower surface (200) in the direction near the central plane (500), and the second outer anti-chip surface (42) extends towards the side of the upper surface (100) in the direction near the central plane (500). The length of the cross section of the first rake face (3) in the central plane (500) along the X direction is L1. One end of the anti-chip structure (4) is tangent to the first rake face (3), and the distance between the tangent position and the front cutting edge (1) in the X direction is L2, where L1 > L2. The X direction, the Y direction, and the Z direction are perpendicular to each other.

2. The cutting blade according to claim 1, characterized in that, 0.08mm≤L1≤0.35mm, 0.05mm≤L2≤0.3mm.

3. The cutting blade according to claim 1, characterized in that, The intersection line between the inner chip-reversing surface (41) and the preset cross section perpendicular to the Y direction is the inner chip-reversing cross section curve. The closer the inner chip-reversing cross section curve is to the center plane (500), the smaller the rate of curvature change of the inner chip-reversing cross section curve.

4. The cutting blade according to claim 3, characterized in that, The intersection line of the second outer anti-chip surface (42) and the inner anti-chip surface (41) is an intersection curve (900). Along the direction away from the front cutting edge (1), the intersection curve (900) first extends through an arc curve to the side where the upper surface (100) is located to a preset highest point K, and then extends from the preset highest point K to the side where the lower surface (200) is located. The distance between the preset highest point K and the front cutting edge (1) in the X direction is L3, and the distance between the preset highest point K and the front cutting edge (1) in the Z direction is H1, where 0.5mm≤L3≤2.5mm and 0.2mm≤H1≤0.6mm.

5. The cutting blade according to claim 4, characterized in that, The intersection line between the first outer chip-reversing surface (44) and the first preset plane (600) perpendicular to the X direction includes an outer chip-reversing straight line segment (441), and the included angle between the outer chip-reversing straight line segment (441) and the second preset plane (700) perpendicular to the Z direction is β2, 0°≤β2≤5°; And / or, the first rake face (3) is a plane, and the angle between the first rake face (3) and the second preset plane (700) perpendicular to the Z direction is β1, 5°≤β1≤10°; And / or, the distance between the intersecting curve (900) and the transverse cutting edge (2) located on the same side of the central plane (500) in the Y direction is L4, 0.1mm≤L4≤0.7mm.

6. The cutting blade according to claim 4, characterized in that, The upper surface (100) is provided with a first chip groove (6), and the first chip groove (6) is smoothly connected to the first rake face (3) and the inner anti-chip surfaces (41) of the two anti-chip structures (4); The distance between the tangent positions of the two anti-chip structures (4) in the Y direction is L5, 0.5mm≤L5≤3.5mm.

7. The cutting blade according to claim 6, characterized in that, The upper surface (100) is provided with a second chip groove (7), and the first chip groove (6) is located between the second chip groove (7) and the first rake face (3) in the X direction. The second chip groove (7) is connected to the inner anti-chip surfaces (41) of the two anti-chip structures (4).

8. The cutting blade according to claim 7, characterized in that, The projection of one end of the anti-chip structure (4) connected to the first rake face (3) in the preset projection plane extends along a preset straight line M, and the preset straight line M gradually approaches the second chip groove (7) in a direction away from the front cutting edge (1); the second chip groove (7) is located between the preset straight lines M of the two anti-chip structures (4); The angle between the preset straight line M and the central plane (500) is β3, where 3°≤β3≤10°, and the preset projection plane is perpendicular to the Z direction.

9. The cutting blade according to claim 6, characterized in that, The inner anti-chip surface (41) is provided with a protrusion (5), and the circumferential edge of the protrusion (5) is smoothly connected to the inner anti-chip surface (41); the intersecting curve (900) intersects with the third preset plane (800) at point Q, and point Q is closer to the upper surface (100) than the intersection line of the protrusion (5) and the third preset plane (800), and the third preset plane (800) is perpendicular to the X direction.

10. The cutting blade according to claim 6, characterized in that, The first rake face (3) and the first chip groove (6) are smoothly connected by an arc. The straight line where the first rake face (3) intersects the central plane (500) is called the rake face straight line. The point where the end of the first chip groove (6) connected to the arc intersects the central plane (500) is point P. The tangent line of the first chip groove (6) passing through point P and located in the central plane (500) is called the groove tangent line. The straight line of the front cutting face intersects the groove tangent at point J, the front cutting edge (1) intersects the center plane (500) at point O, and the distance between point O and point J in the X direction is L1; the angle between the groove tangent and the second preset plane (700) perpendicular to the Z direction is β4, 15°≤β4≤35°.

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