Cutting insert, cutting tool, and method of manufacturing a workpiece

Abstract

A cutting insert based on an aspect of the present disclosure that is not limited has an upper surface that is polygonal in shape and has a first edge, a lower surface, and side surfaces. The side surfaces have a first side surface located between the first edge and the lower surface. The first side surface has a flat first region. The first region has a first central region, a first upper region located closer to the upper surface than the first central region and having a greater width than the first central region, and a first lower region located closer to the lower surface than the first central region and having a greater width than the first central region.

Description

Technical Field

[0001] This application claims priority to Japanese Patent Application No. 2020-096644, filed on June 3, 2020, the entire disclosure of which is incorporated herein by reference. Technical Field

[0003] This disclosure relates to cutting inserts, cutting tools, and methods for manufacturing workpieces generally used in the cutting of workpieces. More specifically, it relates to cutting tools used in rotary cutting processes. Background Technology

[0004] Cutting inserts used for machining workpieces such as metals include, for example, those described in Japanese Patent Application Publication No. 2007-125669 (Patent Document 1), Japanese Patent Application Publication No. 2008-511464 (Patent Document 2), and Japanese Patent Application Publication No. 2017-056552 (Patent Document 3). The cutting inserts described in Patent Documents 1 to 3 each have an upper surface, a lower surface, a side surface, an upper cutting edge, and a lower cutting edge. When the cutting insert is mounted on a tool holder, a portion of the side surface of the cutting insert abuts against the tool holder.

[0005] When cutting a workpiece, a cutting load is applied to the cutting insert. Therefore, it is necessary to stably fix the cutting insert to the tool holder. Summary of the Invention

[0006] A cutting insert based on an undefined aspect of this disclosure has: an upper surface, which is polygonal in shape and has a first side; a lower surface, located on the opposite side of the upper surface; a side surface, located between the upper surface and the lower surface; an upper cutting edge, located at the intersection of the upper surface and the side surface; and a lower cutting edge, located at the intersection of the lower surface and the side surface. A central axis is defined by an imaginary straight line passing through the center of the upper surface and the center of the lower surface. The side surface has a first lateral surface located between the first side and the lower surface. The first side surface is convex in a cross-section orthogonal to the central axis and has: a flat first region; and a flat second region inclined relative to the first region. The first region has: a first central region; a first upper region located closer to the upper surface than the first central region and having a greater width in a direction orthogonal to the central axis compared to the first central region; and a first lower region located closer to the lower surface than the first central region and having a greater width in a direction orthogonal to the central axis compared to the first central region. Attached Figure Description

[0007] Figure 1This is a perspective view showing a cutting insert of an undefined aspect of this disclosure.

[0008] Figure 2 Observing from another direction Figure 1 The three-dimensional view of the cutting blade shown.

[0009] Figure 3 Observation from above Figure 1 The top view of the cutting blade shown.

[0010] Figure 4 Observing from below Figure 1 The bottom view of the cutting blade shown.

[0011] Figure 5 Observed from direction A1 Figure 3 The side view of the cutting blade shown.

[0012] Figure 6 Is with Figure 5 The side view shown is the same as the cutting blade shown.

[0013] Figure 7 Observed from the A2 direction Figure 3 The side view of the cutting blade shown.

[0014] Figure 8 Viewed from the A3 direction Figure 3 The side view of the cutting blade shown.

[0015] Figure 9 Is with Figure 5 The side view shown is the same as the cutting blade shown.

[0016] Figure 10 yes Figure 9 The cross-sectional view of the cutting blade at the X section shown.

[0017] Figure 11 yes Figure 9 The cutting blade shown is a cross-sectional view of section XI.

[0018] Figure 12 yes Figure 9 The cutting insert shown is a cross-sectional view of section XII.

[0019] Figure 13 yes Figure 9 The cutting insert shown is a cross-sectional view of section XIII.

[0020] Figure 14 yes Figure 9 The cross-sectional view of section XIV of the cutting insert shown.

[0021] Figure 15 yes Figure 9 The cross-sectional view of the XV section of the cutting insert shown.

[0022] Figure 16 This is a perspective view showing a cutting tool of an undefined aspect of this disclosure.

[0023] Figure 17 yes Figure 16 The side view of the cutting tool shown.

[0024] Figure 18 It is Figure 16 The enlarged image obtained by magnifying region B1 shown.

[0025] Figure 19 This is a schematic diagram illustrating one step in a method for manufacturing a machined object according to an undefined aspect of this disclosure.

[0026] Figure 20 This is a schematic diagram illustrating one step in a method for manufacturing a machined object according to an undefined aspect of this disclosure.

[0027] Figure 21 This is a schematic diagram illustrating one step in a method for manufacturing a machined object according to an undefined aspect of this disclosure. Detailed Implementation

[0028] <Cutting inserts>

[0029] Hereinafter, a cutting insert 1 (hereinafter, sometimes referred to as "insert 1") of an unlimited aspect of this disclosure will be described in detail using the accompanying drawings. However, in the figures referred to below, only the main components required for illustrating the embodiments are shown in a simplified manner for ease of explanation. Therefore, the insert 1 can include any constituent components not shown in the figures referred to. In addition, the dimensions of the components in the figures do not accurately represent the actual dimensions of the constituent components or the dimensional ratios of each component.

[0030] like Figures 1 to 15 As shown in the undefined example, the cutting tool 1 may have an upper surface 3, a lower surface 5, a side surface 7, an upper cutting edge 9, and a lower cutting edge 11. It should be noted that the terms upper surface 3 and lower surface 5 are used for convenience and do not indicate any upward or downward directionality. For example, the upper surface 3 does not necessarily face upwards when the cutting tool 1 is being used. The same applies to other parts that include the terms "upper" and "lower".

[0031] The upper surface 3 can be polygonal. Additionally, the lower surface 5 can be located on the opposite side of the upper surface 3. The lower surface 5 can also be polygonal, just like the upper surface 3. Furthermore, the blade 1 can be a polygonal plate shape.

[0032] Examples of polygonal shapes include triangles, quadrilaterals, pentagons, hexagons, and octagons. For example, such as... Figure 1 As shown in the undefined example, the upper surface 3 can be rectangular. It should be noted that the polygonal shape does not need to be strictly polygonal. For example, the edges of the upper surface 3 may not be strictly straight lines; they may curve when viewed from above. Furthermore, the angles of the upper surface 3 between adjacent edges may not be strictly angles. In other words, the angles of the upper surface 3 may not be strictly angles. In the case of a top view, the angles can be convex curves, or they can be shapes combining straight lines and curves. The same applies to the lower surface 5.

[0033] An imaginary straight line passing through the center of the upper surface 3 and the center of the lower surface 5 can be the central axis O1 of the blade 1. If the upper surface 3 is polygonal, the center can be the intersection of straight lines connecting opposite corners of the upper surface 3. The starting point of the diagonal can be the intersection of the extensions of the sides constituting the polygon. Alternatively, the center of the upper surface 3 can be the centroid of the upper surface 3 when viewed from above. The center of the lower surface 5 can be defined in the same way as the center of the upper surface 3.

[0034] When viewed from above, the upper surface 3 is rotationally symmetrical about the central axis O1 by 180°. Similarly, when viewed from the front (looking down) at the lower surface 5, the lower surface 5 is rotationally symmetrical about the central axis O1 by 180°.

[0035] The blade 1 is not limited to a specific size. For example, the maximum amplitude when viewing the upper surface 3 from above can be set to approximately 4 to 25 mm. Furthermore, the height from the upper surface 3 to the lower surface 5 can be set to approximately 5 to 20 mm. The height from the upper surface 3 to the lower surface 5 can refer to the maximum value of the distance between the upper surface 3 and the lower surface 5 in the direction parallel to the central axis O1. In other words, the height from the upper surface 3 to the lower surface 5 can also be expressed as the width of the side surface 7 along the direction of the central axis O1.

[0036] Side 7 can be located between the upper surface 3 and the lower surface 5. For example... Figure 7 as well as Figure 8 As shown in the undefined example, side 7 can be connected to the upper surface 3 and the lower surface 5.

[0037] The upper cutting edge 9 can be located at the intersection of the upper surface 3 and the side surface 7. The upper cutting edge 9 can be used to cut the workpiece when using the insert 1 to manufacture the workpiece.

[0038] The upper cutting edge 9 may be located entirely within the aforementioned intersecting area, or it may be located only within a portion of the intersecting area. When viewed from the front (side) or top (top) view of the side 7, the upper cutting edge 9 may be a straight line or a curved line. Furthermore, when viewed from the side or top, the upper cutting edge 9 may also be a shape combining straight lines and curves.

[0039] When the insert 1 has an upper cutting edge 9, one of the upper surface 3 and the side surface 7 may have a rake face region, and the other of the upper surface 3 and the side surface 7 may have a flank face region. For example... Figure 1 As shown in the undefined example, the upper surface 3 may have a rake face region and the side surface 7 may have a flank face region.

[0040] The lower cutting edge 11 can be located at the intersection of the lower surface 5 and the side surface 7. The lower cutting edge 11, like the upper cutting edge 9, can be used to cut the workpiece when using the insert 1 to manufacture the workpiece.

[0041] The lower cutting edge 11 can be located entirely within the aforementioned intersecting area, or it can be located only within a portion of the intersecting area. In side or bottom views, the lower cutting edge 11 can be a straight line or a curved line. Furthermore, in side or bottom views, the lower cutting edge 11 can also be a combination of a straight line and a curved line. It should be noted that when the insert 1 has both an upper cutting edge 9 and a lower cutting edge 11, the insert 1 can be a double-sided device.

[0042] The upper surface 3 may include a first side 13. That is, the upper surface 3 may have a first side 13. Additionally, the upper surface 3 may also include a second side 15 and a third side 17. Specifically, the upper surface 3 may have a second side 15 adjacent to one end of the first side 13 and a third side 17 adjacent to the other end of the first side 13. The lengths of the first side 13, the second side 15, and the third side 17 may be the same, or they may be different. For example, as... Figure 1 As shown in the undefined example, the lengths of the second side 15 and the third side 17 can be longer than the length of the first side 13. Furthermore, the lengths of the second side 15 and the third side 17 can be the same. The first side 13 can be one of the shorter sides of the upper surface 3 of the rectangle. The second side 15 and the third side 17 can each be one of the longer sides of the upper surface 3 of the rectangle.

[0043] Side 7 may have a first side 19. The first side 19 may be located between the first side 13 and the lower surface 5. In addition, side 7 may also have a second side 21 and a third side 23. Specifically, side 7 may have a second side 21 located between the second side 15 and the lower surface 5 and a third side 23 located between the third side 17 and the lower surface 5.

[0044] The blade 1 may have a through hole 25 with openings at the center of the second side 21 and the center of the third side 23. The through hole 25 can be used for inserting a screw, for example, when fixing the blade 1 to the tool holder. It should be noted that, when fixing the blade 1 to the tool holder, a clamping member can be used instead of a screw.

[0045] An imaginary straight line passing through the center of the second side 21 and the center of the third side 23 can be considered as the central axis O2 of the through hole 25. The central axis O2 of the through hole 25 can be orthogonal to the central axis O1 of the blade 1. Orthogonal means not strictly orthogonal, allowing a range of approximately 90° ± 5°. It should be noted that the centers of the second side 21 and the third side 23 can be defined in the same way as the center of the upper surface 3.

[0046] Here, as Figure 11 As shown in the undefined example, the first side surface 19 can be convex in a cross-section orthogonal to the central axis O1. Furthermore, the first side surface 19 can have a flat first region 27 and a flat second region 29 inclined relative to the first region 27. The first region 27 and the second region 29 can serve as so-called constraint surfaces when the cutting tool 1 is mounted to the tool holder. It should be noted that the second region 29 can have a portion adjacent to the first region 27 in a direction orthogonal to the central axis O1.

[0047] The first region 27 and the second region 29 do not need to be strictly flat. The first region 27 and the second region 29 only need to be generally flat areas, and can be slightly curved to a degree that is indistinguishable when the blade 1 is viewed as a whole, or can have minute unevenness. For example, the first region 27 and the second region 29 can have minute unevenness on the order of tens of μm.

[0048] like Figure 5 As shown in the undefined example, the first region 27 may have a first central region 31, a first upper region 33, and a first lower region 35.

[0049] The first upper region 33 can be located closer to the upper surface 3 than the first central region 31. In other words, the first upper region 33 can be located between the first central region 31 and the upper surface 3. Furthermore, the first upper region 33 can have a larger width in the direction orthogonal to the central axis O1 compared to the first central region 31. That is, the width W12 of the first upper region 33 in the direction orthogonal to the central axis O1 can be larger than the width W11 of the first central region 31 in the same direction. It should be noted that the size relationship of the widths can be evaluated by comparing the maximum values ​​of the widths.

[0050] The first lower region 35 can be located closer to the lower surface 5 than the first central region 31. In other words, the first lower region 35 is located between the first central region 31 and the lower surface 5. Furthermore, the first lower region 35 has a larger width in the direction orthogonal to the central axis O1 compared to the first central region 31. That is, the width W13 of the first lower region 35 in the direction orthogonal to the central axis O1 is larger than the width W11 of the first central region 31 in the same direction.

[0051] An imaginary plane orthogonal to the central axis O1 and located midway between the upper surface 3 and the lower surface 5 can be designated as surface S. Surface S may include the central axis O2. The first upper region 33 may be located between surface S and the upper surface 3. The first central region 31 and the first lower region 35 may be located between surface S and the lower surface 5. Furthermore, the width of the first central region 31 along the direction of the central axis O1 may be equal to the width of the first lower region 35. That is, a line passing through the midpoint along the direction of the central axis O1 between the lower end of surface S and the lower end of the first region 27, and orthogonal to the central axis O1, may be the boundary 57 between the first central region 31 and the first lower region 35.

[0052] When the first region 27 is used as the constraint surface, it is easy to stably constrain the insert 1 relative to the tool holder if the width W12 of the first upper region 33 is larger than the width W11 of the first central region 31. When cutting the workpiece with the first region 27 used as the constraint surface, it is possible to apply a force to the insert 1, such as causing it to rotate about the central axis O2 of the through hole 25 due to the main component force. However, even when such a force is applied, the insert 1 is easily and stably constrained in the first upper region 33.

[0053] When the first region 27 is used as a constraint surface, it is easy to stably constrain the insert 1 relative to the tool holder if the width W13 of the first lower region 35 is larger than the width W11 of the first central region 31. When cutting the workpiece with the first region 27 used as a constraint surface, for example, a back force generated by the lower cutting edge 11 may be applied to the insert 1.

[0054] Here, the first lower region 35, being located near the lower surface 5, readily withstands the aforementioned back force. Therefore, even when the aforementioned back force is applied, the first lower region 35, with its large width W13, readily and stably withstands the back force. As a result, the blade 1 is easily and stably constrained.

[0055] Furthermore, the width of the first region 27 in the direction orthogonal to the central axis O1 is not large over its entirety, but rather the width W11 of the first central region 31 is relatively small. Therefore, the width of the second region 29 in the direction orthogonal to the central axis O1 can also be ensured. Thus, even when cutting the workpiece with the second region 29 used as a constraint surface, it is easy to stably constrain the insert 1 relative to the tool holder.

[0056] It should be noted that the first central region 31 can be connected to the first upper region 33, or it can be separated from the first upper region 33. The first central region 31 can be connected to the first lower region 35, or it can be separated from the first lower region 35. For example, as... Figure 5 As shown in the undefined example, the first central region 31 is connected to the first upper region 33 and the first lower region 35, respectively.

[0057] The maximum value of the width W12 of the first upper region 33 in the direction orthogonal to the central axis O1 can be the same as the maximum value of the width W13 of the first lower region 35 in the direction orthogonal to the central axis O1; alternatively, it can be different from the maximum value of that width W13. For example, as... Figure 5 As in the undefined example shown, the maximum value of width W12 can be greater than the maximum value of width W13. In this case, the mitigation effect on stress concentration in the tool holder during cutting is high.

[0058] Widths W11, W12, and W13 can be constant, or they can vary. For example, ... Figure 5 As shown in the undefined example, the first central region 31 may have a portion whose width W11 increases as it approaches the upper surface 3. Furthermore, the width W11 may be greatest at the end of the first central region 31 on the side of the upper surface 3. The first upper region 33 may have a portion whose width W12 increases as it approaches the upper surface 3. The width W12 may be greatest at the end of the first upper region 33 on the side of the upper surface 3. The first lower region 35 may have a portion whose width W13 increases as it approaches the upper surface 3. The width W13 may be greatest at the end of the first lower region 35 on the side of the upper surface 3.

[0059] The first side surface 19 may also have a first flank face 37. The first flank face 37 may be located between the first region 27 and the upper surface 3. Figure 14As in the undefined example shown, the first region 27 can be located closer to the central axis O1 than the first flank face 37 in the cross-section along the central axis O1. In this case, the distance from the central axis O1 to the first region 27 is shorter, thus reducing the force required to rotate the insert 1 during cutting and making it easier to maintain stable constraints. It should be noted that when evaluating the positional relationship with the central axis O1, an imaginary straight line O1a located inside the insert 1 and parallel to the central axis O1 can be used as a reference.

[0060] The first region 27 can be closer to the central axis O1 in the section along the central axis O1 as it approaches the upper surface 3. In this case, the insert 1 is more easily drawn into the tool holder's groove during cutting. Therefore, the insert 1 is easily and stably constrained to the tool holder.

[0061] The first region 27 can be connected to or separated from the lower surface 5. When the first region 27 is connected to the lower surface 5, it is easy to ensure that the area of ​​the first region 27 is large. Therefore, the blade 1 is easily and stably fixed relative to the tool holder.

[0062] like Figure 5 As shown in the undefined example, the second region 29 may have a second central region 39, a second upper region 41, and a second lower region 43.

[0063] The second upper region 41 can be located closer to the upper surface 3 than the second central region 39. In other words, the second upper region 41 can be located between the second central region 39 and the upper surface 3. Furthermore, the second upper region 41 has a larger width in the direction orthogonal to the central axis O1 compared to the second central region 39. That is, the width W22 of the second upper region 41 in the direction orthogonal to the central axis O1 is larger than the width W21 of the second central region 39 in the same direction.

[0064] The second lower region 43 can be located closer to the lower surface 5 than the second central region 39. In other words, the second lower region 43 can be located between the second central region 39 and the lower surface 5. Furthermore, the second lower region 43 can be wider than the second central region 39 in the direction orthogonal to the central axis O1. That is, the width W23 of the second lower region 43 in the direction orthogonal to the central axis O1 can be larger than the width W21 of the second central region 39 in the same direction.

[0065] The second lower region 43 can be located between surface S and the lower surface 5. The second central region 39 and the second upper region 41 can be located between surface S and the upper surface 3. In addition, the widths of the second central region 39 and the second upper region 41 along the direction of the central axis O1 can be equal. That is, the boundary 53 of the second central region 39 and the second upper region 41 can be defined by a line passing through the midpoint between surface S and the upper end of the second region 29 along the direction of the central axis O1 and orthogonal to the central axis O1.

[0066] When the second region 29 is used as a constraint surface, it is easy to stably constrain the insert 1 relative to the tool holder if the width W23 of the second lower region 43 is larger than the width W21 of the second central region 39. When cutting the workpiece with the second region 29 used as a constraint surface, it is possible to apply a force to the insert 1, such as causing it to rotate about the central axis O2 of the through hole 25 due to the main component force. However, even when such a force is applied, the insert 1 is easily and stably constrained in the second lower region 43.

[0067] When the second region 29 is used as a constraint surface, it is easier to stably constrain the insert 1 relative to the tool holder if the width W22 of the second upper region 41 is larger than the width W21 of the second central region 39. When cutting the workpiece with the second region 29 used as a constraint surface, for example, a back force generated by the upper cutting edge 9 may be applied to the insert 1.

[0068] At this time, the second upper region 41, being located near the upper surface 3, easily withstands the aforementioned back force. Therefore, even when the aforementioned back force is applied, the second upper region 41, with its large width W22, easily and stably withstands the back force. As a result, the blade 1 is easily and stably constrained.

[0069] Furthermore, the width of the second region 29 in the direction orthogonal to the central axis O1 is not larger overall, but the width W21 of the second central region 39 is relatively smaller. Therefore, the width of the first region 27 in the direction orthogonal to the central axis O1 can also be ensured. Thus, when cutting the workpiece with the first region 27 used as a constraint surface, it is easy to stably constrain the insert 1 relative to the tool holder.

[0070] It should be noted that the second central region 39 can be connected to the second upper region 41, or it can be separated from the second upper region 41. Similarly, the second central region 39 can be connected to the second lower region 43, or it can be separated from the second lower region 43. For example, as... Figure 5 As shown in the undefined example, the second central region 39 can be connected to the second upper region 41 and the second lower region 43 respectively.

[0071] The maximum value of the width W23 of the second lower region 43 in the direction orthogonal to the central axis O1 can be the same as the maximum value of the width W22 of the second upper region 41 in the direction orthogonal to the central axis O1, or it can be different from the maximum value of that width W22. For example, as Figure 5 As in the undefined example shown, the maximum value of width W23 can be greater than the maximum value of width W22. In this case, the mitigation effect on stress concentration in the tool holder during cutting is high.

[0072] Widths W21, W22, and W23 can be constant, or they can vary. For example, ... Figure 5 As shown in the undefined example, the second central region 39 has a portion whose width W21 increases as it approaches the lower surface 5. Furthermore, the width W21 may be greatest at the end of the second central region 39 on the lower surface 5 side. The second upper region 41 may have a portion whose width W22 increases as it approaches the lower surface 5. The width W22 may be greatest at the end of the second upper region 41 on the lower surface 5 side. The second lower region 43 may have a portion whose width W23 increases as it approaches the lower surface 5. The width W23 may be greatest at the end of the second lower region 43 on the lower surface 5 side.

[0073] The first side surface 19 may also have a second flank face 45. The second flank face 45 may be located between the second region 29 and the lower surface 5. Figure 15 As in the undefined example shown, the second region 29 can be located closer to the central axis O1 than the second flank face 45 in the cross section along the central axis O1. In these cases, the distance from the central axis O1 to the second region 29 is shorter, thus reducing the force required to rotate the insert 1 during cutting and making it easier to maintain stable control.

[0074] The second region 29 can be closer to the central axis O1 in the section along the central axis O1 as it approaches the lower surface 5. In this case, the insert 1 is more easily pulled into the tool groove of the tool holder during cutting. Therefore, the insert 1 is easily and stably constrained to the tool holder.

[0075] The second region 29 can be connected to or separated from the upper surface 3. When the second region 29 is connected to the upper surface 3, it is easy to ensure that the area of ​​the second region 29 is large. Therefore, the blade 1 is easily and stably fixed relative to the tool holder.

[0076] like Figure 6As shown in the undefined example, the first upper region 33 can be adjacent to the second central region 39 in a direction orthogonal to the central axis O1. In this case, the width of the first upper region 33 can be ensured to be wider, thus the range of the constraint surface can be larger. Therefore, the tool holder can be easily and stably constrained to the cutting tool 1. It should be noted that the above structure can mean that the center 33a of the first upper region 33 along the direction of the central axis O1 is adjacent to the second central region 39 in a direction orthogonal to the central axis O1.

[0077] The second lower region 43 can be adjacent to the first central region 31 in a direction orthogonal to the central axis O1. In this case, the width of the second lower region 43 can be ensured to be larger, thus the range of the constraint surface can be larger. Therefore, the blade 1 can be easily and stably constrained to the tool holder. It should be noted that the above structure means that the center 43a of the second lower region 43 along the direction of the central axis O1 is adjacent to the first central region 31 in a direction orthogonal to the central axis O1.

[0078] The first upper region 33 may have a portion located closer to the third side surface 23 than the first flank face 37 in a direction orthogonal to the central axis O1. In this case, the first upper region 33 is located closer to the third side surface 23 than the first flank face 37, so the insert 1 is less likely to protrude from the tool holder to the outer periphery during cutting, and can be stably constrained.

[0079] The second lower region 43 may have a portion located closer to the second side surface 21 than the second flank face 45 in a direction orthogonal to the central axis O1. In this case, the second lower region 43 is located closer to the second side surface 21 than the second flank face 45, so the insert 1 is less likely to protrude from the tool holder to the outer periphery during cutting, and can be stably constrained.

[0080] The width W12 of the first upper region 33 in the direction orthogonal to the central axis O1 can be the same as the width W3 of the first flank face 37 in the direction orthogonal to the central axis O1, or it can be different from that width W3. For example, as Figure 5 As shown in the undefined example, the width W12 can be larger than the width W3.

[0081] The width W23 of the second lower region 43 in the direction orthogonal to the central axis O1 can be the same as the width W4 of the second flank face 45 in the direction orthogonal to the central axis O1, or it can be different from the width W4. For example, as Figure 5 As shown in the undefined example, the width W23 can be larger than the width W4.

[0082] The areas of the first central area 31, the first upper area 33, and the first lower area 35 can be the same, or they can be different. For example, Figure 5 As shown in the undefined example, the first central region 31 may be smaller in area compared to the first upper region 33 and the first lower region 35. Conversely, the first upper region 33 may be larger in area compared to the first lower region 35.

[0083] The areas of the second central region 39, the second upper region 41, and the second lower region 43 can be the same, or they can be different. For example, Figure 5 As shown in the undefined example, the second central region 39 may be smaller in area compared to the second upper region 41 and the second lower region 43. Conversely, the second lower region 43 may be larger in area compared to the second upper region 41.

[0084] like Figure 6 As shown in the undefined example, in a side view, the boundary 47 of the first central region 31 and the first upper region 33 can coincide with surface S. In a side view, boundary 47 can coincide with the central axis O2 of the through hole 25. Furthermore, in a side view, the boundary 49 of the second central region 39 and the second lower region 43 can coincide with surface S. In a side view, boundary 49 can coincide with the central axis O2 of the through hole 25.

[0085] The first side surface 19 may also have a first step portion 51 located between the first region 27 and the first back face 37. The boundary 53 of the second central region 39 and the second upper region 41 may be adjacent to the first step portion 51 in a direction orthogonal to the central axis O1.

[0086] The first side surface 19 may also have a second step portion 55 located between the second region 29 and the second flank face 45. The boundary 57 between the first central region 31 and the first lower region 35 is adjacent to the second step portion 55 in a direction orthogonal to the central axis O1.

[0087] Materials for the cutting tool 1 can include, for example, cemented carbide and cermet. Compositions of cemented carbide can include, for example, WC-Co, WC-TiC-Co, and WC-TiC-TaC-Co. Here, WC, TiC, and TaC can be hard particles, and Co can be a binder phase.

[0088] Furthermore, cermets can be sintered composite materials formed by combining metal and ceramic components. Examples of cermets include titanium compounds with titanium carbide (TiC) or titanium nitride (TiN) as the main components. Of course, the material of blade 1 is not limited to the above composition.

[0089] The surface of the blade 1 can be coated using chemical vapor deposition (CVD) or physical vapor deposition (PVD). Examples of coating compositions include titanium carbide (TiC), titanium nitride (TiN), titanium carbonitride (TiCN), and aluminum oxide (Al2O3).

[0090] <Cutting Tools>

[0091] Next, use Figures 16-18 The cutting tool 101, which is not limited to one aspect of this disclosure, will be described. Furthermore, in Figure 16 In the figure, the rotation axis O3 of the cutting tool 101 is represented by a double-dotted line, and the rotation direction of the rotation axis O3 is represented by an arrow Y1.

[0092] like Figures 16-18 As shown in the undefined example, the cutting tool 101 may have a tool holder 103 and an insert 1. When the cutting tool 101 has an insert 1, the insert 1 can be stably fixed to the tool holder 103, thus achieving excellent cutting performance.

[0093] The cutting tool 101 is capable of rotating about the rotation axis O3. The cutting tool 101 can be used for rotary cutting.

[0094] The handle 103 can be a cylindrical shape extending from the first end 103a to the second end 103b along the rotation axis O3. The cylindrical shape only needs to be approximately cylindrical, and does not need to be a strictly cylindrical shape.

[0095] The tool holder 103 may have a cutting groove 105 located on the first end 103a side. The cutting blade 1 can be installed in the cutting groove 105. The cutting groove 105 may have openings on the outer peripheral surface of the tool holder 103 and the end face on the first end 103a side.

[0096] The cutting insert 1 can be located within the tool groove 105. It should be noted that there can be only one tool groove 105, or there can be multiple tool grooves 105. When the tool holder 103 has multiple tool grooves 105, the cutting tool 101 can have multiple cutting inserts 1. In addition, one cutting insert 1 can be located in each tool groove 105.

[0097] When the tool holder 103 has multiple tool slots 105, these tool slots 105 can be arranged at equal intervals around the rotating shaft O3, or they can be arranged at unequal intervals.

[0098] The insert 1 can be mounted in the tool holder 105 such that at least a portion of its cutting edge protrudes from the tool holder 103. For example, the insert 1 can also be mounted in the tool holder 103 such that its upper cutting edge 9 protrudes from the tool holder 103 toward the workpiece. In this case, the lower surface 5 and the side surface 7 can abut against the tool holder 103.

[0099] The blade 1 can be mounted to the tool holder 105 by screw 107. That is, the screw 107 can be inserted into the through hole 25 of the blade 1, and the front end of the screw 107 can be inserted into the threaded hole formed in the tool holder 105, so that the screw 107 is fixed in the threaded hole, thereby mounting the blade 1 to the tool holder 103.

[0100] Materials for the handle 103 include, for example, steel and cast iron. When the handle 103 is made of steel, it has high toughness.

[0101] <Methods for manufacturing machined parts>

[0102] Next, use Figures 19-21 A method for manufacturing a workpiece 203 that is not limited to one aspect of this disclosure will be described.

[0103] The workpiece 203 can be manufactured by machining the workpiece 201. The method for manufacturing the workpiece 203 may include the following steps:

[0104] (1) A process of rotating the cutting tool 101 represented by the above-described undefined embodiments;

[0105] (2) The process of bringing the rotating cutting tool 101 into contact with the workpiece 201; and

[0106] (3) The process of removing the cutting tool 101 from the workpiece 201.

[0107] Specifically, firstly, such as Figure 19 As shown in the undefined example, the cutting tool 101 can be rotated relative to the workpiece 201 while moving in the Y1 direction about the rotation axis O3. Then, as... Figure 20 As shown in the undefined example, the upper cutting edge 9 of the cutting tool 101 can be brought into contact with the workpiece 201 to cut the workpiece 201. Furthermore, as... Figure 21 As in the undefined example shown, the cutting tool 101 can also be positioned relatively away from the workpiece 201.

[0108] By performing the aforementioned processes, a machined part 203 with high precision of the finished surface can be obtained. Specifically, in the manufacturing method of the machined part 203, when using a cutting tool 101 with insert 1, the insert 1 can be stably fixed to the tool holder 103, thus achieving excellent machinability. As a result, a machined part 203 with high precision of the finished surface can be obtained.

[0109] It should be noted that, in Figures 19-21In one example that is not limited to the one shown, the workpiece 201 to be cut is fixed and the cutting tool 101 is moved in each process, but of course it is not limited to this manner.

[0110] For example, in step (1), the workpiece 201 can be brought closer to the cutting tool 101. Similarly, in step (3), the workpiece 201 can be moved away from the cutting tool 101. If the cutting process continues, the cutting tool 101 can be kept in a rotating state, and the process of bringing the upper cutting edge 9 of the insert 1 into contact with different parts of the workpiece 201 can be repeated.

[0111] Examples of materials that can be used for the workpiece 201 include carbon steel, alloy steel, stainless steel, cast iron, and non-ferrous metals.

[0112] Explanation of reference numerals in the attached figures

[0113] 1...Cutting inserts (blades)

[0114] 3... Top surface

[0115] 5...lower surface

[0116] 7...side view

[0117] 9... Upper cutting edge

[0118] 11...lower cutting edge

[0119] 13...First side

[0120] 15...Second side

[0121] 17... Third side

[0122] 19...First profile

[0123] 21...Second side view

[0124] 23...Third side view

[0125] 25... Through hole

[0126] 27...First District

[0127] 29...Second Zone

[0128] 31...First Central Region

[0129] 33...First Upper Region

[0130] 33a..Central

[0131] 35...First Lower Region

[0132] 37...First back face

[0133] 39...Second Central Region

[0134] 41...Second Upper Region

[0135] 43...Second Lower Region

[0136] 43a..Central

[0137] 45...Second back face

[0138] 47...boundary

[0139] 49...boundary

[0140] 51...First Step

[0141] 53...boundary

[0142] 55...Second Step

[0143] 57...boundary

[0144] 101... Cutting tools

[0145] 103...handle

[0146] 103a..First end

[0147] 103b..Second End

[0148] 105... Tool Groove

[0149] 107... screw

[0150] 201...workpiece

[0151] 203...workpiece

[0152] O1...Central axis of the cutting insert

[0153] O2...Central axis of the through hole

[0154] O3... Rotation axis.

Claims

1. A cutting insert, wherein the cutting insert has: an upper surface which is polygonal in shape and has a first edge; a lower surface which is located on the opposite side of the upper surface; a side surface which is located between the upper surface and the lower surface; an upper cutting edge which is located at a position where the upper surface and the side surface intersect; and a lower cutting edge which is located at a position where the lower surface and the side surface intersect, a central axis which is a straight line that passes through the center of the upper surface and the center of the lower surface, the cutting insert further has an imaginary plane which is orthogonal to the central axis and is located midway between the upper surface and the lower surface, the side surface has a first side surface which is located between the first edge and the lower surface, the first side surface is convex in shape in a cross section which is orthogonal to the central axis, and the first side surface has: a flat first region; and a flat second region which is inclined with respect to the first region, the first region has: a first central region; a first upper region which has a position where, in a side view, a position coinciding with the imaginary plane is a boundary, is located closer to the upper surface than the first central region, and has a maximum value of a width in a direction orthogonal to the central axis which is greater than that of the first central region; and a first lower region which has a line which is orthogonal to the central axis and passes through an intermediate point in a direction along the central axis between a lower end of the first region and the imaginary plane as a boundary, is located closer to the lower surface than the first central region, and has a maximum value of a width in a direction orthogonal to the central axis which is greater than that of the first central region.

2. The cutting insert according to claim 1, wherein the maximum value of the width in the direction orthogonal to the central axis of the first upper region is greater than the maximum value of the width in the direction orthogonal to the central axis of the first lower region.

3. The cutting insert according to claim 1 or 2, wherein the first side surface further has a first relief surface which is located between the first region and the upper surface, the first region is located closer to the central axis than the first relief surface in a cross section along the central axis.

4. The cutting insert according to claim 1 or 2, wherein the first region is closer to the central axis as closer to the upper surface in a cross section along the central axis.

5. The cutting insert according to claim 1, wherein the second region has: a second central region; a second upper region which has a line which is orthogonal to the central axis and passes through an intermediate point in a direction along the central axis between an upper end of the second region and the imaginary plane as a boundary, is located closer to the upper surface than the second central region, and has a maximum value of a width in a direction orthogonal to the central axis which is greater than that of the second central region; and a second lower region which has a position where, in a side view, a position coinciding with the imaginary plane is a boundary, is located closer to the lower surface than the second central region, and has a maximum value of a width in a direction orthogonal to the central axis which is greater than that of the second central region. ​ ​ ​ 6. The cutting insert according to claim 5, wherein a maximum value of the width of the second lower region in a direction orthogonal to the central axis is larger than a maximum value of the width of the second upper region in the direction orthogonal to the central axis.

7. The cutting insert according to claim 5 or 6, wherein the first side surface further has a second relief surface located between the second region and the lower surface, the second region is located closer to the central axis than the second relief surface in a cross section along the central axis.

8. The cutting insert according to claim 5 or 6, wherein the second region is closer to the central axis as closer to the lower surface in a cross section along the central axis.

9. The cutting insert according to claim 5 or 6, wherein the first upper region is adjacent to the second central region in a direction orthogonal to the central axis.

10. The cutting insert according to claim 5 or 6, wherein the second lower region is adjacent to the first central region in a direction orthogonal to the central axis.

11. A cutting tool, wherein the cutting tool has: a shank which is cylindrical in shape extending along a rotation axis from a first end to a second end, and has an insert pocket located on the first end side; and the cutting insert according to any one of claims 1 to 10 is located in the insert pocket.

12. A method of manufacturing a cutting work, wherein the method of manufacturing the cutting work includes: a step of rotating the cutting tool according to claim 11; a step of bringing the rotating cutting tool into contact with a workpiece; and a step of separating the cutting tool from the workpiece.

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