Cutting insert, cutting tool and manufacturing method for producing a machined product

Abstract

An insert (1) comprising: a main body (3) comprising a first surface (7), a second surface (9) arranged on a side opposite to the first surface (7), a side surface (11) arranged between the first surface (7) and the second surface (9), a first cutting edge (17) arranged on at least a part of a ridge line at which a first side surface (13) of the side surface (11) intersects a second side surface (15) adjacent to the first side surface (13), and a through hole (19) open in the first surface (7) and the second surface (9), wherein the main body (3) further comprises a first concave part (21) arranged from the first surface (7) to the side surface (11), and a second concave part (33) arranged from the first surface (7) to the side surface (11), wherein in a front view of the first surface (7) the first concave part (21) is arranged on one side of the second side surface (15) with respect to an imaginary straight line (L1) connecting the first cutting edge (17) and a center of the through hole (19), and a straight line passing through the center of the through-hole (19) and orthogonal to the imaginary straight line (L1) is a vertical line (L2), the first concave part (21) intersects the vertical line (L2), and the second concave part (33) is arranged on an opposite side of the second side surface (15) with respect to the imaginary straight line (L1), is arranged further away from the first cutting edge (17) than the center of the through hole (19) and is arranged away from the imaginary straight line (L1) and the vertical line (L2).

Description

TECHNICAL FIELD

[0001] The present embodiments relate to a cutting insert, a cutting tool, and a method for producing a machined product. More particularly, the present embodiments relate to cutting tools for use in a grooving operation. BACKGROUND

[0002] As a cutting tool used in a cutting process of a workpiece, for example, a cutting tool described in JP 2014-504561 A is known. An insert in the cutting tool described in JP 2014-504561 A has a concave part located on one side of a top surface. A holder in the cutting tool described in JP 2014-504561 A has a convex part corresponding to the concave part. The insert is securely retained by the holder by fitting the concave part to the convex part. In the insert described in JP 2014-504561 A, in a front view of the top surface, the concave part is located on an imaginary line connecting a cutting edge of the insert and a central axis of a through hole.

[0003] Furthermore, from US 2011 / 0 200 408 A1, US 2013 / 0 266 384 A1, DE 602 10 249 T2, or JP S61-75 909 U an insert is known, comprising: a main body having a first surface, a second surface arranged on a side opposite to the first surface, a side surface arranged between the first surface and the second surface, a first cutting edge arranged on at least a part of a ridge line at which a first side surface of the side surface intersects a second side surface adjacent to the first side surface, and a through hole open in the first surface and the second surface, wherein the main body further comprises a first concave part arranged from the first surface to the side surface, and in a front view of the first surface, the first concave part is arranged away from an imaginary straight line connecting the first cutting edge and a center of the through hole.

[0004] It is an object of the present invention to provide a connecting structure between an insert and a cutting tool, which ensures a stable fastening of the insert to the cutting tool during machining. SUMMARY

[0005] The object is achieved by an insert having the features of claim 1. The object is further achieved by a cutting tool having the features of claim 11 and by a manufacturing method for a machined product having the features of claim 16. Further embodiments of the insert and the cutting tool are described in the respective dependent claims. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a perspective view showing a cutting insert in one of the embodiments, Fig. 2 is a plan view of the cutting insert used in the Fig. 1 is shown in a front view of a first surface, Fig. 3 is a plan view of the cutting insert used in the Fig. 1 is shown in a front view of a second surface, Fig. 4 is a side view when the cutting insert used in the Fig. 3 is viewed from an A-direction, Fig. 5 is a side view when the cutting insert used in the Fig. 3 is viewed from a B direction, Fig. 6 is a side view when the cutting insert used in the Fig. 3 is viewed from a C-direction, Fig. 7 is a sectional view showing a cross section along the line II in the Fig. 2 shows, Fig. 8 is a side view when the cutting insert used in the Fig. 3 is viewed from a D-direction, Fig. 9 is a sectional view showing a cross section along the line II-II in the Fig. 2 shows, Fig. Figure 10 is a plan view of a modified embodiment of the cutting insert used in the Fig. 2 is shown, Fig. 11 is a sectional view showing a cross section along the line III-III in the Fig. 10 shows, Fig. 12 is a sectional view showing a cross section along the line IV-IV in the Fig. 10 shows, Fig. 13 is a perspective view showing a cutting insert in one of the embodiments, Fig. 14 is a plan view of the cutting insert used in the Fig. 13 is shown in a front view of a first surface, Fig. 15 is a plan view of the cutting insert used in the Fig. 13 is shown in a front view of a second surface, Fig. 16 is a side view when the cutting insert used in the Fig. 15 is viewed from an E direction, Fig. 17 is a side view when the cutting insert used in the Fig. 15 is viewed from an F direction, Fig. 18 is a perspective view showing a cutting tool in one of the embodiments, Fig. 19 is a plan view when the cutting tool used in the Fig. 18 is viewed towards a first end, Fig. 20 is a side view when the cutting tool used in the Fig. 19 is viewed from a G direction, Fig. 21 is a side view when the cutting tool used in the Fig. 19 is viewed from an H-direction, Fig. Fig. 22 is a plan view showing a state in which a screw is removed in the cutting tool used in the Fig. 19 is shown, Fig. 23 is a perspective view of a holder in the cutting tool shown in the Fig. 18 is shown, Fig. Figure 24 is an enlarged view of a portion at a first end in the holder shown in Fig. 23 is shown, Fig. 25 is a plan view when the holder, which is in the Fig. 23 is viewed in the direction of the first end, Fig. 26 is a sectional view showing a cross section along the line IV-IV in the Fig. 25 shows, Fig. 27 is a diagram showing one of the steps in a manufacturing method for a machined product in one of the embodiments, Fig. Fig. 28 is a diagram showing one of the steps in the manufacturing method for a machined product in one of the embodiments, and Fig. 29 is a diagram showing one of the steps in the manufacturing method for a machined product in one of the embodiments. DESIGNSCutting insert

[0006] Cutting inserts 1 (hereinafter also simply referred to as "the inserts 1") in a plurality of embodiments are described in detail below with reference to the drawings. For ease of description, the related drawings hereinafter show, in a simplified form, only major elements necessary for describing the embodiments. Therefore, the inserts 1 in the present disclosure are capable of including any arbitrary elements not illustrated in the related drawings. Dimensions of the elements in each of the drawings are not those that faithfully depict dimensions of actual structural elements and dimensional relationships of these elements.

[0007] The insert 1 in one of the embodiments comprises a main body 3 having a flat plate shape as shown in the Fig. 1 is shown.

[0008] The main body 3 has a first surface 7, a second surface 9 arranged on an opposite side of the first surface 7, and a side surface 11 arranged between the first surface 7 and the second surface 9. The first surface 7 and the second surface 9 may be parallel to each other, as in the embodiment shown in the Fig. 1. The side surface 11 has a first side surface 13 and a second side surface 15 adjacent to the first side surface 13, as shown in the Fig. 1 and Fig. 2 is shown.

[0009] The first side surface 13 may intersect the second side surface 15. In this case, the main body 3 may have a first cutting edge 17 arranged on at least a part of a ridge line at which the first side surface 13 intersects the second side surface 15. In the embodiment shown in the Fig. 2, the first side surface 13 extends from the first cutting edge 17 and has a concave surface shape. In the embodiment shown in Fig. 2, the second side surface 15 extends from the first cutting edge 17 and has a flat surface shape.

[0010] As it is in the Fig. 3, the first side surface 13 may have a rake face region 13a, and the second side surface 15 may have a flank surface region 15a. The rake face region 13a is a region that can be brought into contact with the chips to wind the chips during a cutting operation. In the embodiment shown in Fig. 3, the rake face region 13a is arranged on a part of the first side surface 13 that extends along the first cutting edge 17. The flank region 15a is a region that is recessed to reduce contact with a finished surface of the workpiece during the cutting process. In the embodiment shown in Fig. 3, the flank region 15a is arranged on a part of the second side surface 15 that extends along the first cutting edge 17. However, it is not necessary for the flank region 15a to be in contact with the finished surface during the cutting process.

[0011] The first cutting edge 17 may be located on at least a portion of the entire ridge line where the first side surface 13 intersects the second side surface 15. A so-called honing process may be performed on the first cutting edge 17 located on the ridge line where the first side surface 13 intersects the second side surface 15. In other words, the ridge line where the first side surface 13 intersects the second side surface 15 does not have to have a strict line shape obtained by intersecting the two surfaces.

[0012] The main body 3 has a through hole 19 which is open in the first surface 7 and the second surface 9, as shown in the Fig. 1 or the like. In the embodiment shown in the Fig. 1 and the like, the insert 1 has a cutting portion 5 formed by the first side surface 13, the second side surface 15, and the first cutting edge 17. The cutting portion 5 may protrude in a direction away from a central axis P1 of the through hole 19. The first cutting edge 17 may therefore be located farthest from the central axis P1 of the through hole 19.

[0013] The through-hole 19 can be used as a hole for inserting a fixing tool when attaching the insert 1 to the holder. Examples of the fixing tool include a screw, a wedge, or a solder material.

[0014] The main body 3 may have a flat plate shape as described above, and an outer diameter of each of the first surface 7 and the second surface 9 may be larger than a thickness of the main body 3. The Fig. 1 shows an embodiment of the shape of the main body 3, however, it is not intended to limit the shape of the main body 3 to that shown in the Fig. 1 shown shape.

[0015] In the embodiments, the main body 3 has a first concave part 21, which is arranged from the first surface 7 to the side surface 11. In an embodiment shown in the Fig. 6, the insert 1 tends to be stably fixed to the holder by causing the first concave part 21 to abut against the holder.

[0016] In the front view of the first surface 7 of the main body 3 of the embodiments, the first concave part 21 is arranged away from an imaginary straight line L1. The imaginary straight line L1 connects the first cutting edge 17 and the central axis P1 of the through hole 19. The central axis P1 may be orthogonal to the first surface 7 and the second surface 9. In this case, in the front view of the first surface 7, as shown in the Fig. 2, the central axis P1 is indicated by a point.

[0017] The imaginary straight line L1 is located in an area susceptible to a load during the cutting process. When the first concave portion 21 is located away from the imaginary straight line L1 connecting the first cutting edge 17 and the central axis P1 of the through hole 19, it is easy to ensure a thickness of the main body 3 in the area susceptible to the load during the cutting process. Consequently, the insert 1 has high durability while the insert 1 is stably fixed to the holder by the first concave portion 21.

[0018] As previously shown, the first side surface 13 may have the rake face region 13a and the second side surface 15 may have the flank region 15a. In the embodiment shown in the Fig. 2, the first concave part 21 is not formed on one side of the first side surface 13 (an upper side in the Fig. 2) but on one side of the second side surface 15 (a lower side in the Fig. 2).

[0019] A main force during a cutting operation is more likely to act on the first cutting edge 17 in a direction toward one side of the flank area 15a (a downward direction in the Fig. 2) to be applied as in a direction to one side of the chip surface area 13a (a right-hand direction in the Fig. 2). In the front view of the first surface 7, when the first concave part 21 is located on one side of the second side surface 15, it is easy to receive the main force at a part of the holder opposite to a first wall surface 25. However, the insert 1 tends to be stably fixed to the holder while avoiding excessive load applied to the fixing tool.

[0020] The main force tends to be applied to the first cutting edge 17 in a direction toward the flank portion 15a side during the cutting operation. Therefore, in the front view of the first surface 7, the insert 1 tends to rotate in a counterclockwise direction based on the central axis P1 of the through hole 19. In this case, when the first concave part 21 is arranged at the above position, a part of the holder opposite to the first wall surface 25 is arranged at the above position, and a part of the holder opposite to the first wall surface 25 is arranged at a relatively close position in the counterclockwise direction from the first cutting edge 17. Consequently, the insert tends to be stably fixed to the holder.

[0021] Although as in the embodiment shown in the Fig. 2, the first concave part 21 may be in contact with the through-hole 19 or separated therefrom, the first concave part 21 may be located away from the through-hole 19. Since the insert 1 is fixed to the holder by the fixing tool, a load tends to be applied to an edge of the through-hole 19 in the main body 3.

[0022] By positioning the first concave portion 21 away from the through-hole 19, a thickness of the edge of the through-hole 19 that is susceptible to the load can be ensured. Therefore, a crack is less likely to occur at the edge of the through-hole 19.

[0023] The first concave part 21 can be formed as shown in the Fig. 6, a first bottom surface 23 and a first wall surface 25 arranged between the first bottom surface 23 and the first surface 7. In the embodiment shown in the Fig. 6, the first bottom surface 23 is arranged to be approximately orthogonal to the central axis P1, and the first wall surface 25 is arranged to be approximately orthogonal to the first bottom surface 23. The term "approximately orthogonal to" is a concept that is not limited to such a configuration that is strictly orthogonal, but which allows a range of approximately 80 to 100°.

[0024] The insert 1 can be stably fixed to the holder by ensuring that the first bottom surface 23 and the first wall surface 25 in the insert 1 abut against the holder. The first bottom surface 23 can be a concave surface and a convex surface or alternatively a surface parallel to the first surface 7, as is the case in the embodiment shown in the Fig. 6 is shown.

[0025] The first wall surface 25 may have a third surface 27 and a fourth surface 29 arranged with a vertical line L2 therebetween. The vertical line L2 is in the embodiment shown in the Fig. 2, is orthogonal to the imaginary straight line L1 and passes through the central axis P1 of the through hole 19. A surface located closer to the first cutting edge 17 than the vertical line L2 is referred to as a third surface 27, and a surface located farther from the first cutting edge 17 than the vertical line L2 is referred to as a fourth surface 29.

[0026] When the first wall surface 25 includes the third surface 27, a portion of the holder opposite the third surface 27 tends to be located closer to the first cutting edge 17 than to the locking tool. This helps reduce the load applied to the locking tool, and the insert 1 can therefore be more securely locked by the portion of the holder opposite the third surface 27.

[0027] When the first wall surface 25 includes the fourth wall surface 29, the first wall surface 25 tends to be positioned above the vertical line L2. This allows the load applied to the fixing tool to be further reduced, resulting in a more stable fixing of the insert 1.

[0028] The first wall surface 25 may be approximately parallel to the central axis P1 of the through-hole 19 or may alternatively be inclined relative to the central axis P1 of the through-hole 19. For the purpose of easy visual understanding, an imaginary straight line intersecting the first surface 7 and parallel to the central axis P1 of the through-hole 19 is referred to as an axis P1', and the axis P1' is compared with the first wall surface 25 in one of the embodiments shown in the Fig. 7 or the like. The term "parallel" does not necessarily imply a strictly parallel positional relationship between two sections in question. In particular, the two sections in question can be considered parallel to each other even if they are inclined at approximately 5°.

[0029] The insert 1 may have a connecting surface 25a connecting the first wall surface 25 and the first surface 7, and a connecting surface 25b connecting the first wall surface 25 and the first bottom surface 23.

[0030] In the front view of the first surface 7, an angle formed by an extension line of the imaginary straight line L1 and an imaginary straight line L3 of the ridge line at which the first surface 7 intersects the third surface 27 is indicated by θ1. In the front view of the first surface 7, an angle formed by the extension line of the imaginary straight line L1 and an imaginary straight line L4 is indicated by θ2. The imaginary straight line L4 is a straight line connecting the central axis P1 and an end portion of the ridge line at which the first surface 7 intersects the third surface 27. The end portion has the greatest distance from the central axis P1.

[0031] In cases where θ1 is smaller than θ2, the third surface 27 is relatively approximately parallel to the imaginary straight line L1 in the front view of the first surface 7. A main force applied to the first cutting edge 17 tends to be absorbed by a part of the holder opposite to the third surface 27. The insert 1 can therefore be stably fixed to the holder. The above θ1 and θ2 are not specifically illustrated.

[0032] The first wall surface 25 may further include a fifth surface 31, which is located between the third surface 27 and the fourth surface 29 in the front view of the first surface 7. The fifth surface 31 may have a convex shape toward a side of the outer edge of the main body 3. When the fifth surface 31 has the above configuration, it is easy to ensure a large width between the first concave part 21 and the through-hole 19. Consequently, a crack is less likely to occur around the through-hole 19.

[0033] In cases where the fifth surface 31 has a convex shape, the first concave portion 21 may be arranged along the through-hole 19 so that the width between the first concave portion 21 and the through-hole 19 becomes constant. In this case, a crack is much less likely to occur around the through-hole 19.

[0034] In the front view of the first surface 7, the fifth surface 31 may have a concave shape with respect to one side of the outer edge of the main body 3. It is easy to secure a large area of ​​the first bottom surface 23 when the fifth surface has the above configuration. Therefore, the insert 1 can be stably or securely fixed to the holder.

[0035] The main body 3 may further comprise a second concave part 33 in addition to the first concave part 21, which is arranged from the first surface 7 to the side surface 11. As in the embodiment shown in the Fig. 2, the second concave part 33 may be arranged on one side of the first side surface 13 with respect to the imaginary straight line L1 and may be arranged further away from the first cutting edge 17 than the central axis P1 of the through hole. As in an embodiment shown in Fig. 8, the second concave part 33 may alternatively have a second bottom surface 35 and a second wall surface 37 arranged between the second bottom surface 35 and the first surface 7.

[0036] When the main body 3 has the second concave part 33, the insert 1 can be stably fixed to the holder by causing the second concave part 33 in the insert 1 to abut against the holder.

[0037] As in the embodiment shown in the Fig. 2, the second wall surface 37 may have a sixth surface 39 and a seventh surface 41 and an eighth surface 43. As in the embodiment shown in the Fig. As shown in FIG. 2, the sixth surface 39 and the seventh surface 41 may have a flat surface shape. The eighth surface 43 may be disposed between the sixth surface 39 and the seventh surface 41 and may have a concave shape toward one side of the outer edge of the main body 3.

[0038] In the embodiment shown in the Fig. 2, of the sixth surface 39 and the seventh surface 41, a surface which is arranged relatively close to the first cutting edge 17 is the seventh surface 41. Of the sixth surface 39 and the seventh surface 41, a surface which is arranged relatively far away from the first cutting edge 17 is the sixth surface 39. As in the embodiment shown in the Fig. 2, the second bottom surface 35 may be parallel to the first surface 7. The sixth surface 39 and the seventh surface 41 in the second wall surface 37 may be individually parallel to the central axis P1.

[0039] The sixth surface 39 and the seventh surface 41 in the second wall surface 37 may be individually parallel to the central axis P1 or may alternatively be individually inclined relative to the central axis P1. In an embodiment shown in the Fig. 10 to 12, the sixth surface 39 is inclined to approach an axis P1' as it passes from one side of the second bottom surface 35 to one side of the first surface 7. The Fig. 10 to 12 show a cross section orthogonal to the first surface 7 and sixth surface 39.

[0040] A main force is applied to the first cutting edge 17 in a direction toward one side of the flank area 15a (in a downward direction in the Fig. 10) during the cutting process. The insert 1 tends to be rotated in the counterclockwise direction based on the central axis P1 of the through hole 19 in the front view of the first surface 7. With the above configuration, even though the force is applied to a part of the holder opposite to the sixth surface 39, the force tends to be distributed not only in a rotational direction of the insert 1 (in a right-hand direction in the Fig. 11), but also in a direction along the central axis P1 of the through-hole 19 (in a downward direction in the Fig. 11). Therefore, the insert 1 and the holder are less likely to be deformed and therefore both have improved durability.

[0041] As in the embodiment shown in the Fig. 12, the fourth surface 29 may be inclined to approach the axis P1' as it moves from one side of the first bottom surface 23 toward one side of the first surface 7. The Fig. 12 shows a cross-section orthogonal to the first surface 7 and the fourth surface 29. The angle of inclination of the fourth surface 29 relative to the axis P1' can be set, for example, to approximately 20° to 70°.

[0042] The main body 3 is subjected to the force that tends to rotate it in the front view of the first surface 7 in the counterclockwise direction based on the central axis P1 of the through hole 19 due to the main force applied during the cutting process. The insert 1 can be held against the above force by the part of the holder opposite the sixth surface 39. The insert 1 can be held against the thrust force applied to the main body 3 during the cutting process by the part of the holder opposite the seventh surface 41.

[0043] Of the third surface 23 and the fourth surface 29, a surface located away from the first cutting edge 17 may be the fourth surface 29. Of the sixth surface 39 and the seventh surface 41, a surface located away from the first cutting edge 17 may be the sixth surface 39. In the front view of the first surface 7, a distance between a ridge line at which the first surface 7 intersects the fourth surface 29 and a ridge line at which the first surface 7 intersects the sixth surface 39 may become larger as the distance from the first cutting edge 17 increases.

[0044] Alternatively, the ridge line where the first surface 7 intersects the fourth surface 29 and the ridge line where the first surface 7 intersects the sixth surface 39 may extend in a parallel direction. When the first concave part 21 and the second concave part 33 have the above configuration, it becomes easy to attach the insert 1 to the holder.

[0045] Further alternatively, in the front view of the first surface 7, a bisector L6 of an angle formed by the imaginary extension line L3 and the imaginary extension line L5 may be parallel to a ridge line at which the first surface 7 intersects the fourth surface 29. Alternatively, the bisector L6 may be parallel to a ridge line at which the first surface 7 intersects the sixth surface 39. The imaginary extension line L3 denotes a ridge line at which the first surface 7 intersects the third surface 27. The imaginary extension line L5 denotes a ridge line at which the first surface 7 intersects the seventh surface 41. When the first concave part 21 and the second concave part 33 have the above configuration, it is easy to stably fix the insert 1 to the holder, while it is easy to fasten the insert 1 to the holder.

[0046] The bisector L6 need not be strictly parallel to the ridge line where the first surface 7 intersects the fourth surface 29, but may be inclined at approximately -10 to 10°. Similarly, the bisector L6 need not be strictly parallel to the ridge line where the first surface 7 intersects the sixth surface 39, but may be inclined at approximately -10 to 10°.

[0047] In the front view of the first surface 7, the imaginary extension line L3 can intersect the imaginary extension line L7 on the outside or outside of the insert 1. The imaginary extension line L7 denotes a ridge at which the first surface 7 intersects the sixth surface 39.

[0048] When a cut where the imaginary extension line L3 intersects the imaginary extension line L7 is located on the outer side of the insert 1, a width of a surface located between the fourth surface 29 and the sixth surface 39 is large in a direction vertical to the fourth surface 29 and the sixth surface 39. Therefore, it is easy to ensure a thickness of the surface located between the fourth surface 29 and the sixth surface 39, resulting in improved fracture resistance of the insert 1.

[0049] As in the embodiment shown in the Fig. 2, the side surface 11 may have a third side surface 45 and a fourth side surface 47. As in the embodiment shown in the Fig. As shown in Figure 2, the third side surface 47 may be located farther from the first cutting edge 17 than a vertical line L2, and a radius of curvature may be constant. The fourth side surface 47 may be located between the third side surface 45 and the first side surface 13 and may be closer to the through hole 19 than the third side surface 45.

[0050] When the side surface 11 has the third side surface 45 and the fourth side surface 47, chips generated by the first cutting edge 17 can pass over the first side surface 13 having the rake face portion 13a and flow to the fourth side surface 47. When the distance to the through hole 19 on the fourth side surface 47 is relatively small as described above, it is easy to ensure a space for the chips to pass through on the fourth side 47. Accordingly, the insert 1 satisfying this configuration has improved chip discharge performance.

[0051] The dimensions of the main body 3 are not particularly limited. For example, in the front view of the first surface 7, a length from the central axis P1 to the first cutting edge 17 may be approximately 3 to 20 mm. A distance between the first surface 7 and the second surface 9 may be approximately 2 to 20 mm.

[0052] For example, cemented carbide and cermet are usable as a material of the insert 1. Examples of the composition of the cemented carbide include WC-Co, WC-TiC-Co, and WC-TiC-TaC-Co. WC-Co is produced by adding cobalt (Co) powder to tungsten carbide (WC), followed by sintering. WC-TiC-Co is produced by adding titanium carbide (TiC) to WC-Co. WC-TiC-TaC-Co is produced by adding tantalum carbide (TaC) to WC-TiC-Co.

[0053] Cermet is a sintered composite material obtained by combining metal and a ceramic component. Examples of cermets include those composed primarily of a titanium component, such as titanium carbide (TiC) and titanium nitride (TiN).

[0054] A surface of the insert 1 can be coated with a coating layer using a chemical vapor deposition (CVD) or a physical vapor deposition (PVD) process. Examples of the composition of the coating layer include titanium carbide (TiC), titanium nitride (TiN), titanium carbonitride (TiCN), and aluminum oxide (Al2O3).

[0055] Another cutting insert 1' in the embodiments is described below with reference to the drawings. The following description of the insert 1' in the embodiment focuses on the differences from the insert 1 of the previous embodiment. Therefore, the insert 1' can have configurations that correspond to those shown in the Fig. 1 are the same. Descriptions of identical configurations may be omitted in some cases.

[0056] The other tool 1 of the embodiment has, as shown in the Fig. 13, a main body 3 which has an approximately flat plate shape.

[0057] The main body has a first surface 7, a second surface 9 located on a side opposite the first surface 7, and a side surface 11 located between the first surface 7 and the second surface 9. The main body 3 has a through-hole 19 open in the first surface 7 and the second surface 9. The main body 3 has a protruding part 49 located on the second surface 9 and protruding from the second surface 9 in a direction away from the first surface 7. The protruding part 49 corresponds to the cutting part in the previous insert 1.

[0058] The projecting part 49 in the embodiment shown in the Fig. 13, protrudes in a direction along a central axis P1 of the through hole 19. The protruding part 49 has a second cutting edge 51 located at a portion farthest from the first surface 7. Specifically, the protruding part 49 includes a first protruding surface 53 protruding from the second surface 9 and having a rake face portion, and a second protruding surface 55 adjacent to the first protruding surface 53 and located at a front end of the protruding part 49 and having a flank portion. The protruding part 49 has the second cutting edge 51 located on at least a portion of a ridge line at which the first protruding surface 53 intersects the second protruding surface 55.

[0059] As described above, the insert 1 has the first cutting edge 17 located at least on a part of the ridge line where the first side surface 13 intersects the second side surface 15, and also has the second cutting edge 51 located at least on a part of the ridge line where the first protruding surface 53 intersects the second protruding surface 55.

[0060] The main body 3 has a first concave part 21 arranged from the first surface 7 to the side surface 11. In an embodiment shown in the Fig. As shown in Figure 14, the first concave portion 21 has a first bottom surface 23 and a first wall surface 25 disposed between the first bottom surface 23 and the first surface 7. The insert 1' is easily fixable to the holder by causing the first bottom surface 23 and the first wall surface 25 in the insert 1' to abut against the holder.

[0061] In a transparent front plan view of the first surface 7, the first concave part 21 is arranged away from an imaginary straight line L8. The imaginary straight line L8 connects a center of the second cutting edge 51 and the central axis P1 of the through hole 19. Similar to the insert 1, the insert 1' in the embodiment shown in the Fig. 14, the above configuration, and therefore has improved durability at the imaginary straight line L8 susceptible to a load during a cutting operation. Cutting tool

[0062] A cutting tool in one of the embodiments of the present disclosure is described below with reference to the drawings.

[0063] As it is in the Fig. 18 or the like, the cutting tool 101 of the embodiment comprises a holder 103 and the insert 1 as represented by the previous embodiment. Fig. 18 to 22 show the insert 1 as a cutting insert. It is even possible for the cutting tool 101 to have the insert 1' instead of the insert 1.

[0064] The holder 103 has a rod shape extending from a first end 103a (upper end in the Fig. 20) to a second end 103b (upper right end of the Fig. 18) and has a pocket 105 on one side of the first end 103a.

[0065] The cutting tool 101 has, in an embodiment shown in the Fig. 19 or the like, a screw 107 as a fixing tool. The pocket 105 may have a screw hole 109 extending from one side of the first end to one side of the second end, as shown in Fig. 22. The insert 1 is fixable to the holder 103 by inserting the screw 107 into the screw hole 109 in the holder 103 and into the through hole 19 in the insert 1. Specifically, the screw 107 is inserted into the through hole 19 formed in the insert 1, and a front end of the screw 107 is inserted into the screw hole 109 formed in the holder 103. The screw 107 is then engaged with the screw hole 109.

[0066] An extending direction of the holder 103 having a rod shape may coincide with an extending direction of the central axis P1 in the insert 1.

[0067] The pocket 105 can be formed as in the embodiment shown in Fig. 24, a bottom part 111, a first convex part 113, and a second convex part 115. The bottom part 111 is a part opposite the first surface. The bottom part 111 may be in contact with the first surface in the insert 1 or, alternatively, may have a flat surface shape. The first convex part 113 is a part opposite a first concave part. The second convex part 115 is a part opposite a second concave part.

[0068] The first convex part 113 and the second convex part 115 may protrude from the bottom part 111 in a direction from one side of the second end 103b to one side of the first end 103a. The first convex part 113 may be in contact with the first concave part, and the second convex part 115 may be in contact with the second concave part.

[0069] In the embodiment shown in the Fig. As shown in Figure 24, the first convex portion 113 has a ninth surface 117 opposite the third surface and a tenth surface 119 opposite the fourth surface. The pocket 105 may further include a first portion 123 disposed between the bottom portion 111 and the ninth surface 117, and a second portion 125 disposed between the bottom portion 111 and the tenth surface 119. The first portion 123 may be a curved surface connecting the bottom portion 111 and the ninth surface 117. The second portion 125 may be a curved surface connecting the bottom portion 111 and the tenth surface 119.

[0070] The Fig. 24 and Fig. 25 shows an embodiment in which the first portion 123 and the second portion 125 have a groove shape. Specifically, a part corresponding to the first portion 123 is indicated by the first groove portion 123, and a part corresponding to the second portion 125 is indicated by the second groove portion 125. In the above configuration, a width W1 of the first groove portion 123 may be greater than a width W2 of the second groove portion 125.

[0071] A main force tends to be applied to the first cutting edge in a direction toward one side of a flank area in the insert 1 during a cutting operation. For the insert 1, it is therefore likely to be rotated in an F1 direction, which is a clockwise direction based on a central axis P2 of the screw hole 109. A force tends to be applied to the ninth surface 117 opposite to the third surface, and stress tends to concentrate between the bottom part 111 and the ninth surface 117. However, the insert 1 with the above configuration makes it easy to avoid stress concentration between the bottom part 111 and the ninth surface 117. This ensures high strength of the holder 103.

[0072] As it is in the Fig. 25, the width W1 of the first groove part 123 can be evaluated by a width in a direction orthogonal to the extending direction of the first groove part 123. The Fig. Fig. 25 is a diagram showing when the holder 103 is viewed toward the first end. As shown in Fig. 25, the width W2 of the second groove part 125 can be evaluated by a width in a direction orthogonal to the extending direction of the second groove part 125.

[0073] The entirety of the bottom part 111 may be in contact with the first surface, or only a part of the bottom part 111 may be in contact with the first surface. The entirety of the first convex part 113 may be in contact with the first concave part, or only a part of the first convex part 113 may be in contact with the first concave part. The entirety of the second convex part 115 may be in contact with the second concave part, or alternatively, only a part of the second convex part 115 may be in contact with the second concave part. The entirety of the ninth surface 117 may be in contact with the third surface, or alternatively, only a part of the ninth surface 117 may be in contact with the third surface.The entirety of the tenth surface 119 may be in contact with the fourth surface, or alternatively, only a portion of the tenth surface 119 may be in contact with the fourth surface.

[0074] As in an embodiment described in the Fig. As shown in FIG. 26, the first groove portion 123 may have a portion that becomes shallower as it moves away from an outer peripheral surface 121 of the holder 103. Although stress is more likely to concentrate at a portion of the first groove portion 123 closer to the outer peripheral surface 121 of the holder 103, when the first groove portion 123 has the above configuration, stress concentration at a portion closer to the outer peripheral surface 121 of the holder 103 can be released. It is also possible to ensure a thickness near the screw hole 109 in the holder 103, resulting in improved strength of the holder 103.

[0075] As in the embodiment shown in the Fig. 26, a bottom of the first groove part 123 may have a curved shape or a straight line shape.

[0076] The pocket 105 may have a screw hole 109 extending from one side of the first end 103a toward one side of the second end 103b in the bottom part 111. The first groove part 123 may be in contact with the screw hole 109 or may be arranged remote from the screw hole 109. The first groove part 123 is spaced apart from the screw hole 109 in the embodiment shown in the Fig. 25 is shown, arranged remotely.

[0077] When the insert 1 is fixed to the holder 103 by the fixing tool, a load tends to be applied to an edge of the screw hole 109 in the holder 103. However, if the first groove portion 123 is located away from the screw hole 109, it is easy to ensure a thickness of the holder 103 at the edge of the screw hole 109 that is susceptible to the load. Therefore, it is easy to suppress the occurrence of cracks in the edge of the screw hole 109.

[0078] The central axis P2 of the screw hole 109 in the holder 103 may coincide with or deviate from the central axis P1 of the through hole 19 in the insert 1. When the central axis P1 coincides with the central axis P2, it is easy to screw the insert 1 to the holder 103.

[0079] In the embodiment shown in the Fig. As shown in Figure 22, the central axis P2 deviates from the central axis P1. Fig. Figure 22 shows a positional relationship between the central axis P2 and the central axis P1 in a non-screwed state. The central axis P2 is in the Fig. 22 is indicated by a dot. Fig. 22 shows a cutting tool 101 in a transparent top view of the holder 103 towards the first end.

[0080] In the embodiment shown in the Fig. 22, an imaginary straight line L9 is defined at a ridge line where the first surface 7 intersects the third surface 27. An imaginary straight line parallel to the imaginary straight line L9 and passing through the central axis P1 of the through-hole 19 is referred to as an imaginary straight line L9'. The central axis P2 may be located on one side of the first concave part 21 with respect to the imaginary straight line L9'. When the central axis P2 is eccentric to the central axis P1 as described above, the screw 107 is less likely to loosen after the insert 1 is fixed to the holder 103 by the screw 107.

[0081] Alternatively, as stated in the Fig. 22, the central axis P2 may be located farther away from the first cutting edge 17 than the central axis P1 in a direction along the imaginary straight line L9'. Also in this case, the screw 107 is less likely to loosen after the insert 1 is fixed to the holder 103 by the screw 107.

[0082] For example, steel or cast iron can be used as the holder 103. Of these materials, high-toughness steel may be particularly suitable. Method for producing a machined product

[0083] A manufacturing method for a machined product in one of the embodiments is described below with reference to the drawings.

[0084] The machined product can be manufactured by performing a cutting operation on a workpiece. The method for manufacturing a machined product in the embodiment comprises the following steps: Step (1) of rotating a workpiece 201, Step (2) of bringing the first cutting edge of the cutting tool 101 represented by the above embodiment into contact with the workpiece 201 which is rotated, and Step (3) of moving the cutting tool 101 away from the workpiece 201.

[0085] In particular, the workpiece 201 is first rotated about an axis O1 and the cutting tool 101 is brought relatively close to the workpiece 201, as shown in the Fig. 27. Then, the workpiece 201 is cut by bringing the first cutting edge in the cutting tool 101 into contact with the workpiece 201 which is rotated, as shown in the Fig. 28. Thereafter, the cutting tool 101 is moved relatively away from the workpiece 201, as shown in the Fig. 29 is shown.

[0086] In the above embodiment, the workpiece 201 is brought close by moving the cutting tool 101 in an X1 direction in a state in which the axis O is fixed and the workpiece 201 is rotated. Fig. 28, the workpiece 201 is cut by bringing the first cutting edge in contact with the workpiece 201, which is rotated. In the Fig. 29, the workpiece 201 is moved away by moving the cutting tool 101 in an X2 direction in a state in which the workpiece is rotated.

[0087] During the cutting process in the manufacturing method of the embodiment, the cutting tool 101 is brought into contact with the workpiece 201 or the cutting tool 101 is moved away from the workpiece 201 by moving the cutting tool 101 in each of the above steps. However, it is not intended to be limited to this embodiment.

[0088] For example, in step (1), the workpiece 201 may be brought close to the cutting tool 101. Similarly, in step (3), the workpiece 201 may be moved away from the cutting tool 101. If it is desired to continue the cutting operation, the step of bringing the first cutting edge in use into contact with different portions of the workpiece 201 may be repeated while the workpiece 201 continues to rotate.

[0089] Examples of the material of the workpiece 201 include unalloyed steel, alloy steel, stainless steel, cast iron, and non-ferrous metals.

[0090] Although the embodiments of the present disclosure have been illustrated and described above, the present disclosure is not limited to the foregoing embodiments. It is, of course, possible to implement any embodiments as long as they do not deviate from the scope of the present disclosure. LIST OF REFERENCE SYMBOLS 1, 1' bet 3 main bodies 5 Cutting part 7 first area 9 second area 11 Side surface 13 first side surface 13a Chipping area 15 second side surface 15a Open space area 17 first cutting edge 19 through hole 21 first concave part 23 first floor area 25 first wall surface 25a connecting surface 25b connecting surface 27 third area 29 fourth area 31 fifth area 33 second concave part 35 second floor area 37 second wall surface 39 sixth area 41 seventh area 43 eighth area 45 third side surface 47 fourth side surface 49 preceding part 51 second cutting edge 53 first protruding surface 55 second protruding surface 101 Cutting tools 103 holders 103a first end 103b second end 105 Bag 107 Screw 109 screw hole 111 Base part 113 first convex part 115 second convex part 117 ninth area 119 tenth area 121 Outer edge surface 123 first section (first groove part) 125 second section (second groove part) 201 Workpiece P1 central axis of the through hole P1' axis parallel to the central axis of the through hole P2 central axis of the screw hole L1 imaginary straight line L2 vertical line L3 imaginary extension line L4 imaginary straight line L5 imaginary extension line L6 bisector L7 imaginary extension line L8 imaginary straight line L9 imaginary straight line L9' straight line O1 Axis of the workpiece X1 Direction of movement X2 Direction of movement

Claims

[1] An insert (1) comprising: a main body (3) comprising a first surface (7), a second surface (9) arranged on a side opposite to the first surface (7), a side surface (11) arranged between the first surface (7) and the second surface (9), a first cutting edge (17) arranged on at least a part of a ridge line at which a first side surface (13) of the side surface (11) intersects a second side surface (15) adjacent to the first side surface (13), and a through hole (19) open in the first surface (7) and the second surface (9), wherein the main body (3) further comprises a first concave part (21) arranged from the first surface (7) to the side surface (11), and a second concave part (33) arranged from the first surface (7) to the side surface (11), wherein in a front view of the first surface (7) the first concave part (21) is arranged on one side of the second side surface (15) with respect to an imaginary straight line (L1) connecting the first cutting edge (17) and a center of the through hole (19), and a straight line passing through the center of the through-hole (19) and orthogonal to the imaginary straight line (L1) is a vertical line (L2), the first concave part (21) intersects the vertical line (L2), and the second concave part (33) is arranged on an opposite side of the second side surface (15) with respect to the imaginary straight line (L1), is arranged further away from the first cutting edge (17) than the center of the through hole (19) and is arranged away from the imaginary straight line (L1) and the vertical line (L2). [2] The insert (1) according to claim 1, wherein the first side surface (13) has a rake face portion (13a) and the second side surface (9) has a flank portion (15a), in the front view of the first surface (7), the first concave part (21) is arranged on one side of the second side surface (15) with respect to the imaginary straight line (L1). [3] The insert (1) according to claim 1 or 2, wherein the first concave part (21) is arranged away from the through hole (19). [4] The insert (1) according to any one of claims 1 to 3, wherein the first concave part (21) has a first bottom surface (23) and a first wall surface (25) which is arranged between the first bottom surface (23) and the first surface (7), and in the front view of the first surface (7), the first wall surface (25) has a third wall surface and a fourth wall surface which are arranged by interposing therebetween a vertical line (L2) relative to the imaginary straight line (L1) passing through the center of the through hole (19). [5] The insert (1) according to claim 4, wherein the first wall surface (25) further comprises a fifth wall surface which is arranged between the third surface (27) and the fourth surface (29) in the front view of the first surface (7) and projects toward a side of an outer edge of the main body (3). [6] The insert (1) according to any one of claims 1 to 5, wherein the first side surface (13) has a rake face region (13a) and the second side surface (15) has a flank region (15a), the second concave part (33) has a second bottom surface (35) and a second wall surface (37) arranged between the second bottom surface (35) and the first surface (7), and the second wall surface (37) has a sixth surface (39) and a seventh surface (41) as two surfaces. [7] The insert (1) according to claim 6, wherein the first concave part (21) has a first bottom surface (23) and a first wall surface (25) which is arranged between the first bottom surface (23) and the first surface (7), the first wall surface (25) has a third surface (27) and a fourth surface (29) which are arranged in the front view of the first surface (7) by interposing a vertical line (L2) relative to the imaginary straight line (L1) passing through the center of the through hole (19), and, if this is fulfilled, of the third surface (27) and the fourth surface (29), a surface which is arranged further away from the first cutting edge (17) is the fourth surface (29), and, if this is fulfilled, of the sixth surface (39) and the seventh surface (41), a surface which is arranged further away from the first cutting edge (17) is the sixth surface (39), a ridge line at which the first surface (7) intersects the fourth surface (29) and a ridge line at which the first surface (7) intersects the sixth surface (39) are extended in a parallel direction in the front view of the first surface (7). [8] The insert (1) according to claim 7, wherein, in the front view of the first surface (7), a bisector of an angle formed by an imaginary extension line (L3) of a ridge line at which the first surface (7) intersects the third surface (27) and an imaginary extension line (L5) of a ridge line at which the first surface (7) intersects the seventh surface (41) is parallel to each of a ridge line at which the first surface (7) intersects the fourth surface (29) and a ridge line at which the first surface (7) intersects the sixth surface (39). [9] The insert (1) according to any one of claims 6 to 8, wherein an imaginary straight line (L4) intersecting the first surface and being parallel to a central axis (P1) of the through-hole (19) is an imaginary axis, and in a cross section orthogonal to the first surface (7) and the sixth surface (39), the sixth surface (39) is inclined to approach the imaginary axis as it moves from a side of the second bottom surface (35) toward a side of the first surface (7). [10] A cutting tool (101) comprising: a holder (103) having a rod shape extending from a first end (103a) to a second end (103b) and having a pocket (105) disposed on one side of the first end (103a), and an insert (1) according to any one of claims 1 to 9, wherein the insert (1) is arranged in the pocket (105). [11] The cutting tool (101) according to claim 10, wherein the pocket (105) has a screw hole (109) extending from one side of the first end (103a) towards one side of the second end (103b), a central axis (P1) of the through hole (19) is parallel to a central axis (P2) of the screw hole (109), the first concave part (21) has a first bottom surface (23) and a first wall surface (25) arranged between the first bottom surface (23) and the first surface (7), the first wall surface (25) has a third surface (27) and a fourth surface (29) arranged in the front view of the first surface (7) by interposing a vertical line (L2) relative to the imaginary straight line (L1) passing through the center of the through-hole (19), and in a transparent plan view of the holder (103) towards the first end (103a), the central axis (P2) of the screw hole (19) is arranged on one side of the first concave part (21) with respect to an imaginary straight line which is parallel to a ridge line at which the first surface (7) intersects the third surface (27) and which passes through the central axis (P1) of the through hole (19). [12] The cutting tool (101) according to claim 11, wherein, in a transparent plan view of the holder (103) toward the first end (103a), the central axis (P2) of the screw hole (109) is located farther from the first cutting edge (17) than the central axis (P1) of the through hole (19) in a direction along an imaginary straight line which is parallel to the ridge line at which the first surface (27) intersects the third surface (29) and which passes through the central axis (P1) of the through hole (19). [13] The cutting tool (101) according to any one of claims 10 to 12, wherein the first concave part (21) has a first bottom surface (23) and a first wall surface (25) which is arranged between the first bottom surface (23) and the first surface (7), the first wall surface (25) has a third surface (27) and a fourth surface (29) which are arranged in the front view of the first surface (7) by interposing a vertical line relative to the imaginary straight line passing through a center of the through hole (19), the pocket (105) has a bottom part (111) opposite the first surface (7) and a first convex part (113) opposite the first concave part (21), the first convex part (113) has a ninth surface (117) opposite the third surface (27) and a tenth surface (119) opposite the fourth surface (29), the pocket (105) further comprises a first groove part (123) which is arranged between the bottom part (111) and the ninth surface (117) and is open in an outer peripheral surface of the holder (105), and a second groove part (125) which is arranged between the bottom part (111) and the tenth surface (119) and is open in the outer peripheral surface of the holder (105), the ninth surface (117) is closer to the first cutting edge (17) than the tenth surface (119), and a width of the first groove part (123) is greater than a width of the second groove part (125). [14] The cutting tool (101) according to claim 13, wherein the first groove part (123) has a portion which becomes shallower as it moves away from the outer peripheral surface. [15] The cutting tool (101) according to claim 13 or 14, wherein the pocket (105) has a screw hole (109) extending from a side of the first end (103a) toward a side of the second end (103b), and the first groove part (123) is arranged away from the screw hole (19). [16] A manufacturing method for a machined product, comprising: Rotating a workpiece (201), Bringing the cutting tool (101) according to any one of claims 10 to 15 into contact with the workpiece (201) which is rotated, and Moving the cutting tool (101) away from the workpiece (201).

Images