Cutting insert

Abstract

Cutting insert (10), comprising: Main cutting edges (20) formed on edge parts of a polygonal shape in a top view with a direct view of a top surface (11). Corner cutting edges (30) which are formed on vertex parts of the polygonal shape such that they extend from the main cutting edges (20); Chip breakers (70) formed between the top surface (11) and the main cutting edges (20) break a chip; Main lower parts (72) which are concave between the main cutting edges (20) and the chip breakers (70); first points (40) which are convex at the chip breakers (70); and first bridges (42) formed between the main cutting edges (20) and the first points (40) such that they are lower than the main cutting edges (20) and first points (40); second points (50) which are convexly formed at the chip breakers (70) such that they are spaced apart from the first points (40); and second bridges (52) formed between the main cutting edges (20) and the second points (50) such that they are lower than the main cutting edges (20) and the second points (50); wherein a first highest point (T1) of the first point (40) is lower than the main cutting edge (20) and a second highest point (T2) of the second point (50) is lower than the main cutting edge 20.

Description

[Technical field]

[0001] The present invention relates to a cutting insert and, more particularly, to a cutting insert that can be used for attachment to a tool holder. [State of the art]

[0002] Generally, a cutting insert is attached to a cutting tool, and the cutting tool is attached to a machine tool and used to cut a workpiece.

[0003] A cutting insert in the related art has a polygonal shape, a corner cutting edge is formed at a crest part, a main cutting edge is formed at an edge where a top surface and a lateral side meet, and a chip breaker is formed between the top surface and the main cutting edge.

[0004] As in the attached Fig. 10B, however, in the case of the related art cutting insert, a cutting chip c is discharged while grazing along the chip breaker, so that the chip c and the chip breaker come into contact with each other at two locations (see p4 and p5).

[0005] Since the chip c and the chip breaker come into contact with each other at two locations (see p4 and p5), there is a problem that a cutting load is high because the cutting force is applied to the chip breaker in a state where the cutting force is not reduced.

[0006] Another problem is that since the chip c and the chip breaker come into contact at the two points (see p4 and p5), the contact points may be unstable and chip curls may not form uniformly. If the chip curls are not uniform, the chips will have different sizes, and in particular, a long chip with a large length may be formed. This long chip makes chip evacuation difficult.

[0007] Meanwhile, the cutting insert generates significant heat during the cutting process. The cutting insert must be cooled because the significant heat affects the life of the cutting insert. The cutting chip can exchange heat while in contact with the chip breaker, and the discharge of the heated cutting chip assists in cooling the cutting insert. However, for the cutting insert in the related art, the cooling effect may not be significant because the chip and the chip breaker come into contact with each other at two locations (see p4 and p5). [Related art document][Patent document]

[0008] US patent application publication no. US2015 / 0090081 (April 2, 2015) [Revelation][Technical Problem]

[0009] Therefore, a technical problem to be solved by the present disclosure is to provide a cutting insert that can reduce a cutting load applied to the cutting insert by a cutting chip when the cutting chip is generated and discharged by the cutting insert during performance of a cutting operation, and to improve a cooling effect.

[0010] Moreover, another object of the present disclosure is to provide a cutting insert that can more effectively machine forged steel for a vehicle component.

[0011] Technical problems to be solved by the present disclosure are not limited to the above-mentioned technical problem, and from the following descriptions, other technical problems not mentioned above will be easily apparent to those skilled in the art to which the present disclosure relates. [Technical solution]

[0012] The problem is solved by a cutting insert having the features of patent claim 1.

[0013] To solve the above-mentioned technical problems, a cutting insert according to an embodiment of the present disclosure includes: main cutting edges 20 formed at edge portions of a polygonal shape in a plan view directly viewing a top surface 11; corner cutting edges 30 formed at apex portions of the polygonal shape so as to extend from the main cutting edges 20; chip breakers 70 formed between the top surface 11 and the main cutting edges 20 and breaking a chip; main bottom portions 72 formed concavely between the main cutting edges 20 and the chip breakers 70; first points 40 formed convexly on the chip breakers 70; and first bridges 42 formed between the main cutting edges 20 and the first points 40 so as to be lower than the main cutting edges 20 and the first points 40.and second bridges 52 formed between the main cutting edges 20 and the second points 50 so as to be lower than the main cutting edges 20 and the second points 50; wherein a first highest point T1 of the first point 40 is lower than the main cutting edge 20 and a second highest point T2 of the second point 50 is lower than the main cutting edge 22;

[0014] Furthermore, the cutting insert according to the embodiment of the present disclosure may further include: second points 50 convexly formed on the chip breakers 70 so as to be spaced apart from the first points 40; and second bridges 52 formed between the main cutting edges 20 and the second points 50 so as to be lower than the main cutting edges 20 and the second points 50.

[0015] Furthermore, according to the cutting insert according to the embodiment of the present disclosure, a highest point T1 of the first point 40 may be lower than the main cutting edge 20.

[0016] Furthermore, according to the cutting insert according to the embodiment of the present disclosure, a second highest point T2 of the second point 50 may be lower than the main cutting edge 20.

[0017] Moreover, according to the cutting insert according to the embodiment of the present disclosure, when a first highest point T1 of the first point 40 and a second highest point T2 of the second point 50 are connected by an imaginary line, a first angle a1 is formed between the imaginary line and the main cutting edge 20, the first angle a1 may be an acute angle.

[0018] Moreover, according to the cutting insert according to the embodiment of the present disclosure, the first angle a1 may be 5 degrees to 10 degrees.

[0019] Moreover, according to the cutting insert according to the embodiment of the present disclosure, a distance from a vertex of the corner cutting edge 30 to a first highest point T1 of the first point 40 may be 0.5 mm to 2.0 mm.

[0020] Moreover, according to the cutting insert according to the embodiment of the present disclosure, a distance from a vertex of the corner cutting edge 30 to a second highest point T2 of the second point 50 may be 1.0 mm to 3.5 mm.

[0021] Furthermore, according to the cutting insert according to the embodiment of the present disclosure, a separation distance between the first point 40 and the second point 50 may be 0.5 mm to 2.5 mm.

[0022] Furthermore, according to the cutting insert according to the embodiment of the present disclosure, a main cutting edge land part 22 may be formed on the main cutting edge 20, a corner land part 32 may be formed on the corner cutting edge 30, and a width w1 of the corner land part 32 may be smaller than a width w2 of the main cutting edge 22.

[0023] Furthermore, according to the cutting insert according to the embodiment of the present disclosure, a longitudinal direction of the first point 40 with respect to the main cutting edge 20 may form a second angle a2, and the second angle a2 may be an acute angle.

[0024] Furthermore, according to the cutting insert according to the embodiment of the present disclosure, the second angle a2 may be greater than or equal to 85 degrees and less than 90 degrees.

[0025] Furthermore, according to the cutting insert according to the embodiment of the present disclosure, a longitudinal direction of the second point 50 with respect to the main cutting edge 20 may form a third angle a3, and the third angle a3 may be an acute angle.

[0026] Furthermore, according to the cutting insert according to the embodiment of the present disclosure, the third angle a3 may be greater than or equal to 85 degrees and less than 90 degrees.

[0027] Furthermore, according to the cutting insert according to the embodiment of the present disclosure, when a chip is generated and discharged, the chip and the cutting insert may sequentially come into contact with each other at a first location p1 at one end of the cutting edge land part 22, a second location p2 at the first bridge 42, and a third location p3 at the first point 40.

[0028] Furthermore, the cutting insert according to the embodiment of the present disclosure may further include corner lands 34 formed concavely between the corner cutting edges 30 and the chip breakers 70, in which, when a chip is generated and discharged, the chip and the cutting insert sequentially contact each other at a first location at one end of the corner land 32, a second location at the corner land 34, and a third location at the chip breaker 70.

[0029] Furthermore, according to the cutting insert according to the embodiment of the present disclosure, a workpiece may be forged steel for a vehicle component.

[0030] Further details of the embodiment are contained in the detailed description and in the drawings. [Beneficial effects]

[0031] According to the cutting insert according to the embodiment of the present disclosure configured as described above, a chip generated during a cutting operation comes into contact with the chip breaker at three locations, and as a result, it is possible to reduce a cutting load and improve the life of the cutting insert.

[0032] Furthermore, according to the cutting insert according to the embodiment of the present disclosure, a chip generated during a cutting operation comes into contact with the chip breaker at three locations, and as a result, it is possible to enhance an increase in the effect of cooling the cutting insert because a larger amount of heat is transferred from the cutting insert to the chip.

[0033] Furthermore, when the cutting insert according to the embodiment of the present disclosure generates chips, the chips can form uniform curls and have uniform sizes. Therefore, the chips are advantageously discharged. [Description of the drawings] The Fig. 1 and Fig. 2 are a perspective view and a detail view for explaining a cutting insert according to an embodiment of the present disclosure. The Fig. 3 and Fig. 4 are a plan view and a detail view for explaining an example of the cutting insert according to the embodiment of the present disclosure. Fig. 5 is a cross-sectional view along line AA of Fig. 4. Fig. 6 is a cross-sectional view along line BB of Fig. 4. The Fig. 7 to 9 are views for explaining a cutting process of the cutting insert according to the embodiment of the present disclosure. Fig. 10 is a view for explaining an operation of a point of the cutting insert according to the embodiment of the present disclosure. Fig. 11 is a view for explaining a functional effect of a land part of the cutting insert according to the embodiment of the present disclosure. Fig. 12 is a view for explaining a size of a chip generated by the cutting insert according to the embodiment of the present disclosure. Fig. 13 is a view for explaining an effect of surface roughness of a surface machined by the cutting insert according to the embodiment of the present disclosure. Fig. 14 is a view for explaining the cutting force applied to the cutting insert according to the embodiment of the present disclosure. Fig. 15 is a view for explaining a lifetime of the point of the cutting insert according to the embodiment of the present disclosure. Fig. 16 is a view for explaining an operating effect of a lower corner part of the cutting insert according to the exemplary embodiment of the present disclosure. [Description of the main reference symbols of the drawings] 10 cutting inserts 11 Top 12 Bottom 13 Lateral side 14 mounting hole 20, 60 main cutting edge 22, 62 Main cutting edge web part 30 corner cutting edge 32 corner web part 34 Corner base 40, 50 First and second points 42, 52 First and second bridge 70 main chip breakers 72 Main lower part T1, T2 First and second highest position W1 Width of the corner web part w2 Width of the main cutting edge web part a1, a2, a3, a4, a5 First to fifth angles h1, h2, h3, h4 First to fifth height s1 Distance from the corner to the highest point of the first point s2 Distance from the corner to the highest point of the second point s3 Distance between the highest point of the first point and the highest point of the second point ap cutting depth p1 ~ p5 contact point w workpiece c Span [Best Practice]

[0034] Advantages and features of the present disclosure and methods of achieving the advantages and features will become apparent with reference to the embodiments described in detail below together with the accompanying drawings.

[0035] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. The embodiments to be described below are provided for understanding the present disclosure, and it should be understood that the present disclosure may be implemented in other ways than those described herein. However, in the description of the present disclosure, the specific descriptions and illustrations of well-known functions and components are omitted when it is determined that the specific descriptions might unnecessarily obscure the subject matter of the present disclosure. Furthermore, for a better understanding of the present disclosure, the accompanying drawings are not illustrated based on actual scales, but portions of the components may be exaggerated in size.

[0036] Meanwhile, terms such as "first" and "second" may be used to describe various components, but the components should not be limited by these terms. These terms are used only to distinguish one component from another. For example, a first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component, without departing from the scope of the present disclosure.

[0037] Meanwhile, the terms used in the specification are defined in consideration of the functions of the present disclosure and may vary depending on the intention or common practice of a manufacturer. Therefore, the definitions should be based on the entire contents of the present specification.

[0038] Throughout the patent specification, like reference numerals indicate like components. <Erstes Ausführungsbeispiel>

[0039] In the following, a cutting insert according to an embodiment of the present disclosure will be described with reference to the Fig. 1 to 6. The attached Fig. 1 and Fig. 2 are a perspective view and a detail view for explaining the cutting insert according to the embodiment of the present disclosure. Fig. 3 and Fig. 4 are a plan view and a detail view for explaining an example of the cutting insert according to the embodiment of the present disclosure. Fig. 5 is a cross-sectional view along line AA of Fig. 4. Fig. 6 is a cross-sectional view along line BB of Fig. 4.

[0040] A cutting insert 10 according to an embodiment of the present disclosure has a polygonal shape. Specifically, the cutting insert 10 has a polygonal shape when viewed in a plan view based on a plane defined by a top surface 11. Further, the cutting insert 10 includes the top surface 11 and the lateral sides 13 defining a thickness (height), and a bottom surface 12 is formed opposite the top surface 11. Furthermore, a fastening hole 14 is formed penetrating the top surface 11 and the bottom surface 12, and the fastening hole 14 is used to fasten the cutting insert 10 to a cutting tool.

[0041] The cutting insert 10 has main cutting edges 20 formed on edge parts of the polygonal shape in plan view based on the plane defined by the top surface 11.

[0042] In addition, the cutting insert 10 has corner cutting edges 30 at apex parts of the polygonal shape, and the corner cutting edge 30 extends from the main cutting edge 20.

[0043] Furthermore, the cutting insert 10 has chip breakers 70 on main lower portions 72 formed between the top surface 11 and the main cutting edges 20. The main lower portion 72 is concave, and the chip breaker 70 is inclined. Furthermore, the chip breaker 70 serves to break a cutting chip.

[0044] Furthermore, the cutting insert 10 according to the embodiment of the present disclosure has first points 40 formed convexly on the chip breaker 70. The first point 40 comes into contact with a chip c when the chip is discharged, so that the chip is hardened to form a curl.

[0045] The first point 40 comes into contact with the chip c when the chip is discharged, so that the chip is hardened to form a curl more effectively, and as a result, a size of the chip can be reduced.

[0046] Furthermore, the cutting insert 10 according to the embodiment of the present disclosure has first bridges 42 formed between the main cutting edges 20 and the first points 40. As shown in Fig. As shown in Figure 5, a first highest point T1 of the first points 40 is lower than the main cutting edge 20 (see h1). Therefore, the chip c can smoothly contact the first point 40 even though a cutting depth ap is small, particularly even though the cutting depth ap is less than 4.5 mm.

[0047] However, the related art patent document does not disclose any technical idea concerning the height of a projection, thus it is difficult to discharge the chip c.

[0048] As in Fig. 5, the first bridge 42 is formed so that it is lower than the main cutting edge 20 and the first point 40 (see h2).

[0049] In particular, the chip comes into contact with the first bridge 42 such that the points at which the chip comes into contact with the cutting insert 10 are positioned on a main cutting edge web part 22 of the first bridge 42 and the first points 40.

[0050] As in Fig. As shown in Figure 10A, the cutting insert 10 according to the embodiment of the present disclosure comes into contact with the chip c at three locations. Based on the first points 40, the three locations include a first location p1 at one end of the cutting edge land portion 22, a second location p2 at the first bridge 42, and a third location p3, which is the first highest location T1.

[0051] If, however, the bridge is not provided as in the related prior art, the contact is made at two points, as in Fig. 10B. The two locations include a fourth location p4 formed on a portion of a main cutting edge land portion 22 formed on one side of a main cutting edge 60, and a fifth location p5 formed on a portion of the chip breaker 70.

[0052] Therefore, heat generated during the cutting process may be transferred to the chip in a more active manner, thereby contributing to a reduction in the degree to which the cutting insert is heated. Furthermore, expected lifetimes of the cutting insert 10 and the cutting tool can be extended by reducing the degree to which the cutting insert is heated. Moreover, the chips c dissipate 70% or more of the heat generated during the cutting process. Furthermore, cutting oil may be introduced into a recess of the chip breaker 70, and the chip may come into direct contact with the cutting oil, so that a temperature of the chip can be directly reduced.

[0053] As in Fig. 3, the cutting insert 10 according to the embodiment of the present disclosure may be formed to be symmetrical with respect to a center line CL passing through a center of the mounting hole 14 and the corner cutting edges 30.

[0054] As in Fig. 3, the cutting insert 10 according to the embodiment of the present disclosure may further be configured to be rotationally symmetrical with respect to the center of the mounting hole 14.

[0055] Therefore, the plurality of main cutting edges 20 and the plurality of corner cutting edges 30 of the cutting insert 10 according to the embodiment of the present disclosure can be used according to a direction in which the cutting insert 10 is fixed. Fig. 3 shows the cutting insert 10 with a rhombic shape, and in this case, the number of main cutting edges 20 is four. In addition, the two corner cutting edges 30 can be used, but since half of the corner cutting edges 30 are universally used and contribute to the cutting process when performing it, the four corner cutting edges 30 can be used.

[0056] On the other hand, the cutting insert 10 according to the embodiment of the present disclosure may be configured to be rotationally symmetrical based on the lateral side 13. That is, the main cutting edges and the corner cutting edges, which are identical to those formed on the top side 11, may also be formed on the bottom side 12.

[0057] As a result, in the cutting insert 10 according to the embodiment of the present disclosure, a maximum of eight main cutting edges and a maximum of eight corner cutting edges can be used when all of the main cutting edges formed on the top surface 11 and all of the main cutting edges formed on the bottom surface 12 are used. <Zweites Ausführungsbeispiel>

[0058] A cutting insert 10 according to a second embodiment of the present disclosure may further include second points 50 in addition to the components of the cutting insert 10 according to the first embodiment.

[0059] The second point 50 is convex on the chip breaker 70 so that it is spaced from the first point 40.

[0060] Furthermore, the cutting insert 10 has second bridges 52 formed between the main cutting edges 20 and the second points 50. As in Fig. 6, the second bridge 52 is designed to be lower than the main cutting edge 20 and the second point 50 (see h4).

[0061] In the cutting insert 10 according to the second embodiment of the present disclosure, the second point 50 is provided to be spaced apart from the first point 40, and as a result, when the cutting depth ap is large (for example, the cutting depth ap is greater than or equal to 3.0 mm), the chip comes into contact with the second point 50, thereby smoothly forming a chip curl.

[0062] As in Fig. As shown in Figure 10A, the cutting insert 10 according to the embodiment of the present disclosure contacts the chip c at three locations. Based on the second location 50, the three locations include a first location p1 at one end of the cutting edge land portion 22, a second location p2 at the second bridge 42, and a third location p3, which is a second highest location T2.

[0063] That is, since the cutting insert 10 according to the second embodiment of the present disclosure has the second bridge 52, the chip c and the second bridge 52 can come into contact with each other when the chip is discharged. The number of contact points between the chip c and the cutting insert 10 is increased, and as a result, it is possible to expect an effect of reducing a cutting load applied to the cutting insert 10 and improving a cooling effect.

[0064] If, however, the bridge is not provided as in the related prior art, the contact is made at two points, as in Fig. 10B. The two locations include the fourth location p4 formed on a part of the main cutting edge land portion 22 formed on one side of a main cutting edge 60, and the fifth location p5 formed on a part of the chip breaker 70.

[0065] Meanwhile, the chips dissipate 70% or more of the heat generated during the cutting process. Furthermore, cutting oil can be introduced into the recess of the chip breaker 70, thereby directly reducing the temperature of the chips.

[0066] On the other hand, hardening of the workpiece occurs at the periphery of the part where the chip c and the second point 50 come into contact with each other, so that bending stress is increased while the chip c is rotated, and as a result, the chip c is cut. As a result, the second point 50 can help more reliably prevent the formation of the chip with a long length.

[0067] In the cutting insert 10 according to the embodiment of the present disclosure, when the chip is generated and discharged, the chip and the cutting insert can sequentially contact each other at the first location at the end of the corner land part 32, the second location at the corner bottom part 34, and the third location at the chip breaker 70. That is, since the chip and the cutting insert come into contact with each other at three locations, it is possible to reduce a cutting load. <Drittes Ausführungsbeispiel>

[0068] A cutting insert 10 according to a third embodiment of the present disclosure is configured such that the first highest point T1 of the first point 40 of the cutting insert 10 according to the first and second embodiments is formed to be lower than the main cutting edge 20. Therefore, resistance can be reduced when the chip is discharged, and as a result, the chip can be discharged quickly.

[0069] Fig. 15A is a view showing an example, and abrasion of the first point 40 is reduced when a height of the first point 40 is lower than a height of the main cutting edge 20.

[0070] Fig. 15B shows a comparative example, and there is a problem in that a part of the highest point of the point is greatly abraded when a height of the point is higher than a height of the main cutting edge.

[0071] Therefore, in the cutting insert 10 according to the third embodiment of the present disclosure, a height of the first point 40 is lower than a height of the main cutting edge 20, and as a result, it is possible to improve a lifetime of the cutting insert. <Viertes Ausführungsbeispiel>

[0072] A cutting insert 10 according to a fourth embodiment of the present disclosure is configured such that the second highest point T2 of the second point 50 of the cutting insert 10 according to the first and second embodiments is formed to be lower than the main cutting edge 20. Therefore, resistance can be reduced when the chip is discharged, and as a result, the chip can be discharged quickly.

[0073] Furthermore, similar to the third embodiment, in the fourth embodiment, abrasion of the second point 50 is reduced when a height of the second point 50 is lower than a height of the main cutting edge 20.

[0074] Therefore, in the cutting insert 10 according to the fourth embodiment of the present disclosure, a height of the second point 50 is lower than a height of the main cutting edge 20, and as a result, it is possible to contribute to the improvement of a lifetime of the cutting insert. <Fünftes Ausführungsbeispiel>

[0075] A cutting insert 10 according to a fifth embodiment of the present disclosure is configured such that when the first highest point T1 of the first point 40 and the second highest point T2 of the second point 50 are connected to each other by an imaginary line, a first angle a1 is formed between the imaginary line and the main cutting edge 20, and the first angle a1 is an acute angle, as shown in Fig. 4 shown.

[0076] With reference to the Fig. 7 to 9, a function of the cutting insert 10 according to the fifth embodiment of the present disclosure is described. The attached Fig. 7 to 9 are views for explaining a cutting process of the cutting insert according to the fifth embodiment of the present disclosure.

[0077] The first point 40 leads, and the second point 50 follows the first point 40 based on a machining direction when the cutting process is performed. Therefore, when the chip c is discharged, the chip c collides with the first point 40 and then collides with the second point 50 with a time shift. Because the chip collides with the first point 40 and the second point 50 with a time shift, it is possible to prevent an increase in the abrasion of the chip breaker 70 and the load applied thereto.

[0078] When the chip c comes into contact with the first point 40 and the second point 50 at the same time, there is a concern that abrasion of the chip breaker 70 and a load applied thereto increase.

[0079] As in the Fig. Meanwhile, as shown in Figures 7 to 9, the main cutting edge 20 can be installed to have a fifth angle a5 with respect to the machining direction when the cutting insert 10 is installed on the cutting tool. Therefore, the chip c can reliably and sequentially contact the first point 40 and the second point 50. <Sechstes Ausführungsbeispiel>

[0080] A cutting insert 10 according to a sixth embodiment of the present disclosure is configured such that the first angle a1 of the cutting insert 10 according to the fifth embodiment is 5 degrees to 10 degrees.

[0081] When the first angle a1 is greater than 5 degrees, the chip can sequentially contact the first point 40 and the second point 50 when the chip is discharged, and as a result, it is possible to prevent a load applied to the chip breaker 70 from being excessively increased.

[0082] Moreover, when the first angle a1 is smaller than 10 degrees, it is possible to prevent a size of a configuration of the chip breaker 70 of the cutting insert 10 from being excessively increased.

[0083] Therefore, the first angle a1 formed between the main cutting edge 20 of the imaginary line connecting the first point 40 and the second point 50 can be 5 degrees to 10 degrees. <Siebtes Ausführungsbeispiel>

[0084] In a cutting insert 10 according to a seventh embodiment of the present disclosure, a distance S1 from a vertex of the corner cutting edge 30 to the highest point T1 of the first tip 40 may be 0.5 mm to 2.5 mm.

[0085] Further, in the cutting insert 10 according to the seventh embodiment of the present disclosure, a workpiece may be forged steel for a vehicle component, and a cutting depth of the workpiece may be 0.5 mm to 3.0 mm.

[0086] A chip curl can be smoothly formed when the first point 40 and the chip c come into contact with each other in the state where the distance S1 from the apex of the corner cutting edge 30 to the first highest point T1 of the first point 40 is in a range of 0.5 mm to 2.0 mm.

[0087] If the distance S1 from the apex of the corner cutting edge 30 to the first highest point T1 of the first point 40 is set to be less than 0.5 mm, a width from the apex to the first point 40, particularly a corner bottom 34, may be formed to be too narrow. In this case, an effect of reducing a cutting load may be impaired. That is, in Fig. 15A, the chip cannot come into contact with the second location p2, and as a result, the chip cannot be machined smoothly.

[0088] Meanwhile, if the distance S1 from the apex of the corner cutting edge 30 to the first highest point T1 of the first point 40 is less than 2 mm, the versatility may be impaired although the point may be functional.

[0089] Versatility is further described. The cutting depth of a forged product is generally 3.0 mm or less, and the cutting depth must allow for a fine grinding process of 0.5 mm. This means that the forged steel for an automotive component must be machined, and a general fine grinding process must be performed to achieve versatility.

[0090] Therefore, if the distance S1 from the apex of the corner cutting edge 30 to the first highest point T1 of the first point 40 is greater than 2.0 mm, fine grinding cannot be performed, and consequently the cutting insert cannot be used to machine the forged steel for a vehicle component.

[0091] However, in the cutting insert according to the embodiment of the present disclosure, the distance S1 from the apex of the corner cutting edge 30 to the first highest point T1 of the first point 40 is 0.5 mm to 2.0 mm, and as a result, it is possible to smoothly cut the forged steel for a vehicle component in which the cutting depth of the workpiece is 0.5 mm to 3.0 mm. <Achtes Ausführungsbeispiel>

[0092] In a cutting insert 10 according to an eighth embodiment of the present disclosure, a distance from the apex of the corner cutting edge 30 to the second highest point T2 of the second point 50 may be 1.0 mm to 3.5 mm.

[0093] A chip curl can be smoothly formed while the second point 50 and the chip c come into contact with each other in the state where the distance S2 from the apex of the corner cutting edge 30 to the second highest point T2 of the second point 50 is in a range of 1.0 mm to 3.5 mm. <Neuntes Ausführungsbeispiel>

[0094] A cutting insert 10 according to a ninth embodiment of the present disclosure is configured such that a separation distance between the first point 40 and the second point 50 may be 0.5 mm to 2.5 mm.

[0095] When the separation distance between the first point 40 and the second point 50 is greater than or equal to 0.5 mm, the chip c can surely and sequentially come into contact with the first point 40 and the second point 50, and as a result, it is possible to prevent an increase in the abrasion of the chip breaker and the load applied thereto.

[0096] In addition, when the separation distance between the first point 40 and the second point 50 is equal to or less than 2.5 mm, it is possible to prevent an excessive increase in a size of the configuration of the chip breaker 70. <Zehntes Ausführungsbeispiel>

[0097] A cutting insert 10 according to a tenth embodiment of the present disclosure is configured such that the main cutting edge land portion 22 is formed on the main cutting edge 20, and the corner land portion 32 is formed on the corner cutting edge 30. A width w1 of the corner land portion 32 may be smaller than a width w2 of the main cutting edge 22.

[0098] In general, as in Fig. 9, under a cutting condition where the cutting depth ap is small, the cutting resistance is relatively small, so that the chip cannot enter the bottom part of the chip breaker 70. However, in the cutting insert 10 according to the tenth embodiment of the present disclosure, since the corner land part 32 of the corner cutting edge 30 is narrow, the chip smoothly enters the main bottom part 72 of the chip breaker 70, so that rough machining can be easily performed.

[0099] Meanwhile, when the depth of cut ap is large, relatively large abrasion (crater wear) occurs on the web part. In particular, during high-speed feed machining, the upper abrasion reaches an auxiliary cutting edge, so that chips are generated from the dimension-determining auxiliary cutting edge, and as a result, the workpiece may be damaged.

[0100] Therefore, in the cutting insert 10 according to the tenth embodiment of the present disclosure, it is possible to prevent the wear form from reaching the corner cutting edge 30 and improve a tool life by changing the land, particularly by forming the cutting insert such that the width w1 of the corner land part 32 is smaller than the width w2 of the main cutting edge land part 22.

[0101] The attached Fig. 11 and Fig. 16 are drawing-replacing photographs for explaining a functional effect of the cutting insert 10 according to the tenth embodiment of the present disclosure.

[0102] The cutting condition is set the same in Example (a) and Comparative Example (b), and the cutting insert shown in Comparative Example (b) has a land part having a constant width.

[0103] As in Fig. As shown in Figure 11B, when the main cutting edge land portion of the main cutting edge and the corner land portion of the corner cutting edge have the same width, the main chip breaker 70 may be abraded, and chip flow may be unstable when the cutting insert is moved at a high speed. Furthermore, a load applied to the corner land portion of the corner cutting edge may be increased, and the portion defining the corner cutting edge may be severely abraded, thus shortening the tool life.

[0104] In particular, when the high-speed feed is performed when performing the cutting process, an abrasion amount of the corner bottom 34 (see the part shown by a circle) of Example (a) of the present disclosure is smaller than that of Comparative Example (b), as shown in Fig. 16A. Furthermore, in Example (a) of the present disclosure, chip flow is stable because the corner bottom 34 is less abraded. As shown in Fig. 11A, the abrasion amount of the real web part (see the part shown by the circle) is therefore reduced.

[0105] As in Fig. 16B, however, in the comparative example (b), the corner base portion 34 (see the part indicated by the circle) is severely abraded compared to the example (a) of the present disclosure, so that chip flow may be unstable. Furthermore, a load applied to the corner land portion is increased when the chip flow is unstable. As shown in Fig. 11B, the corner web part (see the part shown by the circle) can therefore be heavily abraded.

[0106] As in Fig. Therefore, as shown in FIG. 11A, when the width w1 of the corner land portion 32 is smaller than the width w2 of the main cutting edge land portion 22, the corner cutting edge 30 and the corner land portion 32 are subjected to comparatively less wear than the comparative example. That is, a service life of the cutting insert 10 according to the tenth embodiment of the present disclosure can be improved.

[0107] In the following, a functional effect of the cutting insert 10 according to the first to tenth embodiments of the present disclosure will be described with reference to the Fig. 12 to 14 described.

[0108] The attached Fig. 12 is a view for explaining a size of a chip generated by the cutting insert according to the embodiment of the present disclosure. In particular, Fig. 12A illustrates a chip generated by performing the cutting process using the cutting insert 10 according to the embodiment of the present disclosure. Fig. 12B illustrates a chip generated by performing the cutting process using a cutting insert known in the related art.

[0109] Furthermore, the cutting conditions are set identically. This means that the conditions regarding feed rate and cutting depth are set identically.

[0110] When comparing a chip size, as in Fig. 12, it can be seen that a size of the chip c generated by the cutting insert 10 according to Example (a) of the present disclosure is much smaller than that of Comparative Example (b).

[0111] Therefore, the cutting insert 10 according to the embodiment of the present disclosure is advantageous in terms of chip discharge because the sizes of the chips are small and uniform.

[0112] The attached Fig. 13 is a view for explaining an effect of surface roughness of a surface machined by the cutting insert according to the embodiment of the present disclosure.

[0113] Fig. 13A illustrates a case where the cutting depth is set to 0.5 mm, and the cutting depth is shallow. As the feed rate increases, the surface roughness in the example of the present disclosure is better than in the comparative example. In particular, when the feed rate is 0.3 to 0.4 mm / rev, the surface roughness in the example of the present disclosure is much better than in the comparative example.

[0114] Fig. 13B shows a case where the cutting depth is set to 1.5 mm. Similar to Fig. 13A, as the feed rate increases, the surface roughness in the example of the present disclosure is better than in the comparative example. In particular, when the feed rate is 0.3 to 0.4 mm / rev, the surface roughness in the example of the present disclosure is much better than in the comparative example.

[0115] The attached Fig. 14 is a view for explaining the cutting force applied to the cutting insert according to the embodiment of the present disclosure.

[0116] As in Fig. 14, the cutting force in the comparative example when the feed rate is 0.2 mm / rev is 1863 N, and the cutting force in the example of the present disclosure is 1471 N. That is, it can be seen that a cutting load in the example of the present disclosure is smaller than in the comparative example.

[0117] When the feed rate is 0.4 mm / rev, the cutting load in the comparative example is 2390 N, and the cutting load in the example of the present disclosure is 1805 N. Also, it can be seen that the cutting load in the example of the present disclosure is lower than in the comparative example although the feed rate is increased.

[0118] Therefore, the cutting insert 10 according to the embodiment of the present disclosure has the effect of reducing a cutting load by the configurations of the first and second points 40 and 50, the first and second bridges 42 and 52, the main cutting edge land part 22, and the corner land part 32. <Elftes Ausführungsbeispiel>

[0119] As in Fig. 4, the cutting insert 10 according to an eleventh embodiment of the present disclosure is configured such that the first and second points 40 and 50 may have second and third angles a2 and a3 with respect to the main cutting edge 20, and both the second and third angles a2 and a3 may be an acute angle.

[0120] As in Fig.7, when the cutting insert 10 is installed on the cutting tool, the main cutting edge 20 of the cutting insert 10 can be installed at the fifth angle a5 with respect to the machining direction.

[0121] Meanwhile, in the cutting insert 10 according to the eleventh embodiment of the present disclosure, the first and second points 40 and 50 have the second and third angles a2 and a3, so that a forward direction can exist with respect to a direction in which the chip is generated. Therefore, the first and second points 40 and 50 can prevent a cutting load from increasing when the chip is generated.

[0122] On the other hand, both the second and third angles a2 and a3 can be greater than or equal to 85 degrees and less than 90 degrees.

[0123] When the second and third angles a2 and a3 are less than 85 degrees, the first and second points 40 and 50 in a longitudinal direction may be excessively curved, and in this case, a cutting load may be increased when the chip is generated.

[0124] Also, when the second and third angles a2 and a3 are greater than or equal to 90 degrees, the first and second points 40 and 50 in the longitudinal direction may be excessively reversely curved, and in this case, a cutting load may be increased when the chip is generated.

[0125] Therefore, the longitudinal direction of the first and second points 40 and 50 may coincide with or approximately correspond to a direction in which the chip is generated and grows, and as a result, resistance to the movement of the chip is reduced, so that the chip is discharged more smoothly.

[0126] Although the embodiments of the present disclosure have been described with reference to the accompanying drawings, it will be understood by those skilled in the art that the present disclosure may be embodied in any other specific forms without changing the technical spirit or essential feature thereof.

[0127] Accordingly, it should be understood that the above-mentioned embodiment is described in all aspects for illustrative purposes and is not limited, and the scope of the present disclosure is intended to be represented by the claims to be described below, and it should be concluded that any changes or modified forms derived from the meaning and scope of the claims and an equivalent concept thereto are included in the scope of the present disclosure. [Industrial applicability]

[0128] The cutting insert according to the embodiment of the present disclosure can be used to perform a cutting process.

Claims

[1] Cutting insert (10), comprising: Main cutting edges (20) formed on edge portions of a polygonal shape in a plan view with a direct view of a top surface (11) corner cutting edges (30) formed on apex parts of the polygonal shape so as to extend from the main cutting edges (20); Chip breakers (70) formed between the top surface (11) and the main cutting edges (20) and breaking a chip; Main lower parts (72) which are concave between the main cutting edges (20) and the chip breakers (70); first points (40) which are convex on the chip breakers (70); and first bridges (42) formed between the main cutting edges (20) and the first points (40) so as to be lower than the main cutting edges (20) and first points (40); second points (50) convexly formed on the chip breakers (70) so as to be spaced from the first points (40); and second bridges (52) formed between the main cutting edges (20) and the second points (50) such that they are lower than the main cutting edges (20) and the second points (50); wherein a first highest point (T1) of the first point (40) is lower than the main cutting edge (20) and a second highest point (T2) of the second point (50) is lower than the main cutting edge (20). [2] Cutting insert (10) according to claim 1, wherein when a first highest point (T1) of the first point (40) and a second highest point (T2) of the second point (50) are connected by an imaginary line, a first angle (a1) is formed between the imaginary line and the main cutting edge (20), and the first angle (a1) is an acute angle. [3] Cutting insert (10) according to claim 2, wherein the first angle (a1) is 5 degrees to 10 degrees. [4] Cutting insert (10) according to claim 1, wherein a distance (S1) from a vertex of the corner cutting edge (30) to a first highest point (T1) of the first point (40) is 0.5 mm to 2.0 mm. [5] Cutting insert (10) according to claim 1, wherein a distance (S2) from a vertex of the corner cutting edge (30) to a second highest point (T2) of the second point (50) is 1.0 mm to 3.5 mm. [6] Cutting insert (10) according to claim 1, wherein a separation distance (S3) between the first point (40) and the second point (50) is 0.5 mm to 2.5 mm. [7] Cutting insert (10) according to claim 1, wherein a main cutting edge land part (22) is formed on the main cutting edge (20), a corner land part (32) is formed on the corner cutting edge (30), and a width (w1) of the corner land part (32) is smaller than a width (w2) of the main cutting edge land part (22). [8] Cutting insert (10) according to claim 1, wherein a longitudinal direction through the first point (40) forms a second angle (a2) with respect to the main cutting edge (20), and the second angle (a2) is an acute angle. [9] Cutting insert (10) according to claim 8, wherein the second angle (a2) is greater than or equal to 85 degrees and less than 90 degrees. [10] Cutting insert (10) according to claim 1, wherein a longitudinal direction of the second point (50) forms a third angle (a3) ​​with respect to the main cutting edge (20), and the third angle (a3) ​​is an acute angle. [11] Cutting insert (10) according to claim 10, wherein the third angle (a3) ​​is greater than or equal to 85 degrees and less than 90 degrees. [12] Cutting insert (10) according to one of claims 1, 2 to 6, wherein, when a chip is generated and discharged, the chip and the cutting insert (10) come into contact with each other sequentially at a first location (p1) at one end of the cutting edge land part (22), a second location (p2) at the first bridge (42) and a third location (p3) at the first point (40). [13] Cutting insert (10) according to claim 7, further comprising: Corner bases (34) which are concave between the corner cutting edges (30) and the chip breakers (70), wherein, when a chip is generated and discharged, the chip and the cutting insert (10) come into contact with each other sequentially at a first location at one end of the corner web part (32), a second location at the corner bottom part (34) and a third location at the chip breaker (70). [14] Cutting insert (10) according to one of claims 1, 2 to 7, wherein a workpiece is forged steel for a tool component.

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