Rotary tool and method for manufacturing machined product

Abstract

A rotary tool according to an unrestricted aspect of the present disclosure has a shank and a cutting blade. The cutting blade has: an upper surface having a first upper edge; a lower surface having a first lower edge; and side surfaces. The side surfaces have: a first side surface located on the front end side; a second side surface located on the outer peripheral side of the shank; and a third side surface located on the inner peripheral side of the shank. The first upper edge is a convex shape protruding toward the front end and has a first end. The first end is located closer to the third side surface than the second side surface. The first lower edge is a convex shape protruding toward the front end and has a second end. The second end is located closer to the second side surface than the third side surface. When observing the upper surface from the front view, the first side surface has a front end area sandwiched by the first end and the second end, and the front end area is recessed toward the rear end.

Description

[0001] Cross-reference to related applications

[0002] This application claims the benefit of Japanese Patent Application No. 2020-054294, filed on March 25, 2020, and the entire disclosure of that prior application is incorporated herein by reference. Technical Field

[0003] The present disclosure generally relates to a rotary tool used in cutting a workpiece and a method for producing a machined product. More specifically, it relates to a rotary cutting tool used for milling or the like. Background Art

[0004] As a rotary tool (cutting tool) used when cutting a workpiece such as a metal, there are known cutting tools described in International Publication No. 2010 / 114094 (Patent Document 1), International Publication No. 2015 / 174200 (Patent Document 2) and Japanese Patent Application Publication No. 2010-523352 (Patent Document 3). The cutting tool described in Patent Document 3 has a cutting insert. The cutting insert has two end faces (upper surface and lower surface), a peripheral surface, and cutting edges (upper cutting edge and lower cutting edge) formed at the intersection of the end faces and the peripheral surface. The cutting edge is a convex shape protruding toward the front end of the rotation axis, and with the end of the convex shape as a reference, has a main cutting edge located on the outside and a secondary cutting edge located on the inside. The peripheral surface has an area connecting the end of the upper cutting edge and the end of the lower cutting edge. The area connects the two ends in a straight line. Therefore, when the cutting insert is viewed from above, the outer peripheral edge connecting the two ends is a straight line.

[0005] When using the cutting tool described in Reference 3 for cutting, the axial rake angle needs to be set to a large negative value to prevent the above-mentioned area on the peripheral surface from contacting the workpiece. In other words, the cutting insert needs to be tilted forward significantly. However, when the cutting insert is tilted forward significantly, the cutting performance may be reduced. Summary of the Invention

[0006] A rotary tool according to one non-limiting aspect of the present disclosure is a rotary tool extending from a rear end to a front end along a rotational axis, and comprising: a cylindrical shank extending along the rotational axis and having a slit located on the front end side; and a cutting insert located in the slit. The cutting insert comprises: an upper surface located forward in the rotational direction of the rotational axis and having a first upper side located on the front end side; a lower surface located opposite the upper surface and having a first lower side located on the front end side; side surfaces located between the upper and lower surfaces; an upper cutting edge located on the first upper side; and a lower cutting edge located on the first lower side. The side surfaces comprise: a first side surface located on the front end side; a second side surface located on the outer periphery of the shank; and a third side surface located on the inner periphery of the shank. The first upper side is convexly shaped, protruding toward the front end, and has a first end located on the front end side. The first end is located closer to the third side than the second side surface. The first lower side is convexly shaped, protruding toward the front end, and has a second end located on the front end side. The second end is located closer to the second side surface than the third side surface. When the upper surface is viewed from the front, the first side surface has a front end region sandwiched by the first end and the second end, and the front end region is recessed toward the rear end. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 is a perspective view of a rotary cutter illustrating a non-limiting aspect of the present disclosure.

[0008] Figure 2 Observed from the front side Figure 1 A top view of the rotating tool is shown.

[0009] Figure 3 Observed from the direction of A1 Figure 2 A side view of the rotating tool is shown.

[0010] Figure 4 It will Figure 1 An enlarged view of area B1 is shown.

[0011] Figure 5 It will Figure 3 An enlarged view of area B2 is shown.

[0012] Figure 6 Yes Figure 1 A perspective view of a cutting insert in a rotary tool is shown.

[0013] Figure 7 It is a bird's-eye view Figure 6 A top view of the cutting insert is shown.

[0014] Figure 8 It is a bird's-eye view Figure 6 A top view of the cutting insert is shown.

[0015] Figure 9 Looking up Figure 6 A plan view of the cutting insert is shown.

[0016] Figure 10 Observed from the direction of A2 Figure 8 A side view of the cutting insert is shown.

[0017] Figure 11 Observed from the A3 direction Figure 8 A side view of the cutting insert is shown.

[0018] Figure 12 yes Figure 8 A cross-sectional view of section XII-XII is shown.

[0019] Figure 13 yes Figure 8 A cross-sectional view of section XIII-XIII is shown.

[0020] Figure 14 This is a schematic diagram showing one step in a method for producing a machined product according to a non-limiting aspect of the present disclosure.

[0021] Figure 15 This is a schematic diagram showing one step in a method for producing a machined product according to a non-limiting aspect of the present disclosure.

[0022] Figure 16 This is a schematic diagram showing one step in a method for producing a machined product according to a non-limiting aspect of the present disclosure. DETAILED DESCRIPTION

[0023] <Rotating Tool>

[0024] The following describes in detail a rotary cutter 1 according to one non-limiting aspect of the present disclosure using the accompanying drawings. However, for ease of explanation, the following figures illustrate only simplified versions of the essential components necessary to illustrate the embodiment. Therefore, the rotary cutter 1 may include any components not shown in the accompanying figures. Furthermore, the dimensions of the components in the figures do not accurately reflect the actual dimensions of the components or the dimensional ratios of the components.

[0025] The rotary cutter 1 can also be Figures 1 to 5 As shown in the non-limiting example, the rotary tool 1 extends from the rear end 1a to the front end 1b along the rotation axis O1. The rotary tool 1 can also be rotatable around the rotation axis O1. In addition, the rotary tool 1 can also be a rotary cutting tool for milling processing. In addition, Figure 1The arrow Y1 in FIG. 1 represents the rotation direction of the rotation axis O1 .

[0026] The rotary tool 1 may include a shank 3 and a cutting insert 5 (hereinafter, sometimes referred to as “insert 5 ”).

[0027] The shank 3 can be cylindrical, extending along the rotation axis O1. The cylindrical shape need only be roughly cylindrical and need not be strictly cylindrical. Furthermore, the shank 3 can have a blade groove 7 located on the front end 1b side. The blade groove 7 can be a location where the blade 5 can be mounted. The blade groove 7 can open on the outer peripheral surface of the shank 3 and on the end surface on the front end 1b side.

[0028] The blade 5 may also be located in the knife groove 7. It should be noted that there may be only one knife groove 7, or more than one knife groove 7. Figure 2 As shown in the non-limiting example, when the shank 3 has a plurality of blade grooves 7 , the rotary cutter 1 may have a plurality of blades 5 , and one blade 5 may be located in each blade groove 7 .

[0029] When the shank 3 has a plurality of sipes 7 , these sipes 7 may be arranged at equal intervals around the rotation axis O1 , or may be arranged at unequal intervals.

[0030] The handle 3 is not limited to a specific size. For example, the length of the handle 3 along the rotation axis O1 can be set to about 60 to 300 mm. In addition, the width (diameter) of the handle 3 in the direction perpendicular to the rotation axis O1 can also be set to about 8 to 40 mm.

[0031] The blade 5 can also be as Figures 6 to 13 As shown in the non-limiting example, the blade 5 has an upper surface 9, a lower surface 11, a side surface 13, an upper cutting edge 15, and a lower cutting edge 17. It should be noted that the upper surface 9 and the lower surface 11 are shown for convenience and do not indicate up and down directions. For example, the upper surface 9 does not need to face upward when the blade 5 is in use. These points also apply to other parts that include up and down directions.

[0032] The upper surface 9 can also be Figure 2 The upper surface 9 may be located in front of the rotation direction Y1 of the rotation axis O1 as in the non-limiting example shown. Figure 6 As shown in the non-limiting example, it is a substantially quadrilateral shape (rectangular shape).

[0033] Lower surface 11 can also be positioned at the opposite side of upper surface 9. In addition, lower surface 11 can also be polygonal in the same manner as upper surface 9. Lower surface 11 can also be roughly quadrilateral (rectangular shape). And, blade 5 can also be polygonal plate shape. Blade 5 can also be quadrilateral plate shape.

[0034] It should be noted that the polygon does not need to be a strict polygonal shape. For example, the multiple edges in the upper surface 9 may not be strictly straight lines, and may be curved when the upper surface 9 is viewed from the front (viewed from above). In addition, the corners of the upper surface 9 located between adjacent edges may not be strict angles. In other words, the multiple corners on the upper surface 9 may not be strict angles. When the upper surface 9 is viewed from the front, the corners may be convex curves, or may be a combination of straight lines and curves.

[0035] The plurality of sides of the upper surface 9 may include a first upper side 19. That is, the upper surface 9 may have a first upper side 19. The first upper side 19 may be located on the front end 1b side. If the upper surface 9 is a quadrilateral having long and short sides, the first upper side 19 may be a short side.

[0036] The multiple sides of the lower surface 11 may include a first lower side 21. That is, the lower surface 11 may have a first lower side 21. The first lower side 21 may be located on the front end 1b side. If the lower surface 11 is a quadrilateral with long and short sides, the first lower side 21 may be a short side.

[0037] The imaginary straight line passing through the center of the upper surface 9 and the center of the lower surface 11 can also be the central axis O2 of the blade 5. When the upper surface 9 is a quadrilateral, the intersection of the diagonals of the upper surface 9 can also be used as the center of the upper surface 9. Similarly, when the lower surface 11 is a quadrilateral, the intersection of the diagonals in the lower surface 11 can also be used as the center of the lower surface 11. The portion that becomes the starting point of the diagonal line can also be the portion where the extension lines of the respective sides constituting the quadrilateral intersect.

[0038] It should be noted that the shapes of the upper surface 9 and the lower surface 11 are not limited to a quadrilateral, but may be other shapes. Examples of other shapes include triangles, pentagons, hexagons, and octagons. In the case where the upper surface 9 is not a quadrilateral, for example, the center of the upper surface 9 may be determined based on the position of the center of gravity of the upper surface 9 when the upper surface 9 is viewed from the front. Similarly, in the case where the lower surface 11 is not a quadrilateral, for example, the center of the lower surface 11 may be determined based on the position of the center of gravity of the lower surface 11 when the lower surface 11 is viewed from the front (looking up).

[0039] When the upper surface 9 is viewed from the front, the upper surface 9 may be rotationally symmetrical about the central axis O2. When the lower surface 11 is viewed from the front, the lower surface 11 may be rotationally symmetrical about the central axis O2.

[0040] The blade 5 is not limited to a specific size. For example, the maximum width when observing the upper surface 9 from the front view can also be set to about 6 to 25 mm. In addition, the height from the upper surface 9 to the lower surface 11 can also be set to about 1 to 10 mm. The height from the upper surface 9 to the lower surface 11 can also refer to the maximum value of the interval between the upper surface 9 and the lower surface 11 in a direction parallel to the central axis O2. In addition, the height from the upper surface 9 to the lower surface 11 can also be in other words the width of the side 13 in the direction along the central axis O2.

[0041] The side surface 13 may also be located between the upper surface 9 and the lower surface 11. Figure 10 As shown in the non-limiting example, the upper surface 9 and the lower surface 11 are connected.

[0042] The upper cutting edge 15 may also be located on the first upper side 19. The upper cutting edge 15 can be used to cut the workpiece when the insert 5 is used to manufacture the workpiece. The upper cutting edge 15 may be located on the entire first upper side 19 or only on a portion of the first upper side 19.

[0043] In the case where the insert 5 has an upper cutting edge 15, one of the upper surface 9 and the side surface 13 may have a rake face region, and the other of the upper surface 9 and the side surface 13 may have a flank face region. Figure 6 As shown in the non-limiting example, the upper surface 9 has a rake face region, and the side surface 13 has a flank face region.

[0044] The lower cutting edge 17 can be located on the first lower side 21. Like the upper cutting edge 15, the lower cutting edge 17 can be used to cut the workpiece when the insert 5 is used to produce a workpiece. The lower cutting edge 17 can be located on the entire first lower side 21 or only on a portion of the first lower side 21. It should be noted that when the insert 5 has the upper cutting edge 15 and the lower cutting edge 17, the insert 5 can be double-sided.

[0045] Here, the side surface 13 may include a first side surface 23, a second side surface 25, and a third side surface 27. The first side surface 23 may be located on the front end 1b side. When the upper cutting edge 15 is used to produce a workpiece, the second side surface 25 may be located on the outer periphery of the shank 3. When the upper cutting edge 15 is used to produce a workpiece, the third side surface 27 may be located on the inner periphery of the shank 3. It should be noted that the second side surface 25 and the third side surface 27 may be located along the rotation axis O1. The third side surface 27 may be located on the opposite side of the second side surface 25.

[0046] When the lower cutting edge 17 is used to produce a workpiece, the insert 5 can be mounted on the shank 3 in a reversed state, compared to when the upper cutting edge 15 is used to produce a workpiece. Therefore, when the lower cutting edge 17 is used to produce a workpiece, the third side surface 27 can also be located on the outer peripheral side of the shank 3. Alternatively, when the lower cutting edge 17 is used to produce a workpiece, the second side surface 25 can also be located on the inner peripheral side of the shank 3.

[0047] First upper side 19 may have a convex shape that projects toward front end 1b. Furthermore, first upper side 19 may have first end 19a located on the front end 1b side. More specifically, first upper side 19 may have first end 19a located closest to front end 1b within first upper side 19. Furthermore, first end 19a may be located closer to third side 27 than to second side 25. In other words, the distance between first end 19a and third side 27 may be smaller than the distance between first end 19a and second side 25.

[0048] When the upper cutting edge 15 is used to produce a machined product, the portion of the upper cutting edge 15 located near the first end 19a can function as a bottom edge located along the machined surface (finished surface) of the workpiece. The portion of the upper cutting edge 15 extending from the first end 19a to the second side surface 25 can function as a so-called main cutting edge, primarily machining the workpiece. The portion of the upper cutting edge 15 extending from the first end 19a to the third side surface 27 can function as a ramping edge when the upper cutting edge 15 is used for ramping.

[0049] The first lower side 21 may have a convex shape that protrudes toward the front end 1b. Alternatively, the first lower side 21 may have a second end 21a located on the side of the front end 1b. More specifically, the first lower side 21 may have a second end 21a located closest to the front end 1b of the first lower side 21. Alternatively, the second end 21a may be located closer to the second side 25 than to the third side 27. In other words, the distance between the second end 21a and the second side 25 may be smaller than the distance between the second end 21a and the third side 27.

[0050] The portion of the lower cutting edge 17 located near the second end 21a can function as a bottom edge located along the machined surface (finished surface) of the workpiece when the lower cutting edge 17 is used to produce a machined product. The portion of the lower cutting edge 17 located from the second end 21a to the third side surface 27 can function as a so-called main cutting edge, primarily machining the workpiece, when the lower cutting edge 17 is used to produce a machined product. The portion of the lower cutting edge 17 located from the second end 21a to the second side surface 25 can function as a ramping edge when the lower cutting edge 17 is used to perform ramping.

[0051] like Figure 7 As shown in the non-limiting example, when viewing the top surface 9 from the front, the first side surface 23 may have a front end region 29 sandwiched between the first end 19a and the second end 21a. Furthermore, when viewing the top surface 9 from the front, the front end region 29 may be recessed toward the rear end 1a. More specifically, when viewing the top surface 9 from the front, the front end region 29 may be recessed toward the rear end 1a so as to be located closer to the rear end 1a than an imaginary straight line L1 connecting the first end 19a and the second end 21a.

[0052] When observing the upper surface 9 from the front, when the front end area 29 is recessed toward the rear end 1a, it is easy to set the axial rake angle to a smaller negative value than when the front end area 29 is linear. Therefore, the side surface 13 (first side surface 23) of the insert 5 is prevented from contacting the workpiece, and the machinability is high.

[0053] like Figure 8 and Figure 12 As shown in the non-limiting example, when viewing the upper surface 9 from the front, a cross section passing through the first end 19a and perpendicular to the first upper side 19 can be the first cross section. In the first cross section, the side surface 13 (first side surface 23) can be concave. In this case, the side surface 13 (first side surface 23) is less likely to come into contact with the workpiece.

[0054] like Figure 8 and Figure 13 As shown in the non-limiting example, when viewing the upper surface 9 from the front, a cross section passing through the second end 21a and perpendicular to the first lower side 21 can be the second cross section. In the second cross section, the side surface 13 (first side surface 23) can be concave. In this case, the side surface 13 (first side surface 23) is less likely to come into contact with the workpiece.

[0055] like Figure 11As shown in the unrestricted example, when the first side surface 23 is observed from the front (or side), the first upper side 19 can be a convex shape protruding upward. In addition, when the first side surface 23 is observed from the front, the first upper side 19 can have a third end 19b located at a position farthest from the lower surface 11. When the first side surface 23 is observed from the front, the third end 19b can be located directly above the second end 21a. In these cases, when the upper cutting edge 15 is used to manufacture the cut workpiece, the second end 21a is not easily brought into contact with the workpiece due to the third end 19b. In addition, when the lower cutting edge 17 is used to manufacture the cut workpiece, the third end 19b is not easily brought into contact with the workpiece due to the second end 21a.

[0056] It should be noted that the positional relationship of the third end 19b relative to the second end 21a can also be expressed as follows: when observing the first side surface 23 from the front, the imaginary straight line L2 connecting the second end 21a and the third end 19b is parallel to the central axis O2. Parallel is not limited to strict parallelism and can also mean that an inclination of approximately ±5° is allowed.

[0057] When viewing the first side surface 23 from the front, the first lower side 21 may have a convex shape that projects downward. Furthermore, when viewing the first side surface 23 from the front, the first lower side 21 may have a fourth end 21b located farthest from the upper surface 9. When viewing the first side surface 23 from the front, the fourth end 21b may be located directly below the first end 19a. In these cases, when the upper cutting edge 15 is used to produce a machined product, the fourth end 21b is less likely to come into contact with the workpiece due to the first end 19a. Furthermore, when the lower cutting edge 17 is used to produce a machined product, the first end 19a is less likely to come into contact with the workpiece due to the fourth end 21b.

[0058] It should be noted that the positional relationship of the fourth end 21b relative to the first end 19a can also be expressed as follows: when observing the first side surface 23 in a front view, the imaginary straight line L3 connecting the first end 19a and the fourth end 21b is parallel to the central axis O2.

[0059] like Figure 7 As shown in the non-limiting example, the upper surface 9 may have an upper inclined surface 31 and an upper flat surface 33. The upper inclined surface 31 may be located along the upper cutting edge 15. Alternatively, the upper inclined surface 31 may approach the lower surface 11 as it moves away from the upper cutting edge 15. The upper flat surface 33 may be located closer to the center (center) of the upper surface 9 than the upper inclined surface 31. The upper flat surface 33 may be a flat surface. Flatness only means being substantially flat and does not need to be strictly flat.

[0060] The upper inclined surface 31 can be used as a rake face area when the upper cutting edge 15 is used to cut the workpiece. In addition, when the lower cutting edge 17 is used to cut the workpiece, the upper flat surface 33 can also be used as a surface that abuts (contacts) the shank 3 when the blade 5 is fixed to the shank 3. In this case, the upper flat surface 33 can also be positioned as a mounting surface. In addition, the upper flat surface 33 can also be perpendicular to the central axis O2. Perpendicularity is not limited to strict verticality and can also refer to a range of approximately 90°±5°.

[0061] The upper flat surface 33 may have a fifth end 33a located toward the front end 1b. More specifically, the upper flat surface 33 may have a fifth end 33a located toward the front end 1b of the upper flat surface 33. The fifth end 33a may be located closer to the third side surface 27 than to the second side surface 25. In other words, the distance between the fifth end 33a and the third side surface 27 may be smaller than the distance between the fifth end 33a and the second side surface 25. When the upper flat surface 33 is used as the mounting surface for the handle 3, when the fifth end 33a is in the aforementioned position, the fifth end 33a is easily located near the outer periphery of the rotary cutter 1. Therefore, the blade 5 is easily and stably retained on the handle 3.

[0062] Third side surface 27 may be located closer to fifth end 33a than first end 19a. In other words, the distance between third side surface 27 and fifth end 33a may be smaller than the distance between third side surface 27 and first end 19a. When upper flat surface 33 is used as a mounting surface, when fifth end 33a is located in this position, blade 5 is more easily and stably retained on handle 3.

[0063] like Figure 9 As shown in the non-limiting example, the lower surface 11 may have a lower inclined surface 35 and a lower flat surface 37. The lower inclined surface 35 may be located along the lower cutting edge 17. Alternatively, the lower inclined surface 35 may approach the upper surface 9 as it moves away from the lower cutting edge 17. The lower flat surface 37 may be located closer to the center (center) of the lower surface 11 than the lower inclined surface 35. The lower flat surface 37 may also be a flat surface.

[0064] The lower inclined surface 35 can serve as a rake face when the workpiece is cut using the lower cutting edge 17. Furthermore, when the workpiece is cut using the upper cutting edge 15, the lower flat surface 37 can also serve as a surface that abuts (contacts) the tool holder 3 when the insert 5 is secured to the tool holder 3. In this case, the lower flat surface 37 can also serve as a mounting surface. Furthermore, the lower flat surface 37 can be perpendicular to the central axis O2.

[0065] The lower flat surface 37 may have a sixth end 37a located toward the front end 1b. More specifically, the lower flat surface 37 may have the sixth end 37a located toward the most front end 1b of the lower flat surface 37. The sixth end 37a may be located closer to the second side surface 25 than to the third side surface 27. In other words, the distance between the sixth end 37a and the second side surface 25 may be smaller than the distance between the sixth end 37a and the third side surface 27. When the lower flat surface 37 is used as the mounting surface for the handle 3, when the sixth end 37a is located in the above-described position, the sixth end 37a is easily located near the outer periphery of the rotary cutter 1. Consequently, the blade 5 is easily and stably retained on the handle 3.

[0066] The second side surface 25 can be located closer to the sixth end 37a than the second end 21a. In other words, the distance between the second side surface 25 and the sixth end 37a can be smaller than the distance between the second side surface 25 and the second end 21a. When the lower flat surface 37 is used as the mounting surface, when the sixth end 37a is located in the above position, the blade 5 can be more stably held on the handle 3.

[0067] The blade 5 may also have a through hole 39. The through hole 39 can be used to insert a screw, for example, when fixing the blade 5 to the handle 3. It should be noted that, when fixing the blade 5 to the handle 3, a clamping member, for example, may be used instead of a screw.

[0068] The through hole 39 may be opened in the area on the side surface 13 that is located on the opposite sides, or may be opened in the upper surface 9 and the lower surface 11. Figure 6 As shown in the non-limiting example, the through hole 39 may be opened at the center of the upper surface 9 and the center of the lower surface 11. The central axis of the through hole 39 may be an imaginary straight line passing through the center of the upper surface 9 and the center of the lower surface 11. In other words, the central axis of the through hole 39 may also coincide with the central axis O2 of the blade 5.

[0069] The insert 5 can be mounted on the tool groove 7 in a manner such that at least a portion of the upper cutting edge 15 or the lower cutting edge 17 protrudes from the tool handle 3. For example, the insert 5 can also be mounted on the tool handle 3 in a manner such that the upper cutting edge 15 protrudes from the tool handle 3 toward the workpiece. In this case, the lower surface 11 and the side surface 13 can abut against the tool handle 3.

[0070] The blade 5 can also be installed in the knife groove 7 by a screw 41. That is, the screw 41 can be inserted into the through hole 39 of the blade 5, the front end of the screw 41 is inserted into the threaded hole formed in the knife groove 7, and the screw 41 is fixed to the threaded hole, thereby the blade 5 is installed on the handle 3.

[0071] Examples of the material of the handle 3 include steel and cast iron. When the handle 3 is made of steel, the handle 3 has high toughness.

[0072] Examples of materials for the insert 5 include cemented carbide and cermet. Examples of cemented carbide compositions include WC-Co, WC-TiC-Co, and WC-TiC-TaC-Co. WC, TiC, and TaC may be hard particles, and Co may be a binder phase.

[0073] In addition, cermet can also be a sintered composite material with a metal compound in a ceramic component. As an example of cermet, a titanium compound with titanium carbide (TiC) or titanium nitride (TiN) as the main component can be enumerated. Of course, the material of the blade 5 is not limited to the above-mentioned composition.

[0074] The surface of the blade 5 can be coated with a film using a chemical vapor deposition (CVD) method or a physical vapor deposition (PVD) method. Examples of the film composition include titanium carbide (TiC), titanium nitride (TiN), titanium carbonitride (TiCN), and aluminum oxide (Al2O3).

[0075] <Method for Manufacturing Machined Product>

[0076] Next, use Figures 14 to 16 A method for producing the machined product 203 , which is one aspect not limited to the present disclosure, will be described.

[0077] The machined product 203 can be manufactured by machining the workpiece 201. The method for manufacturing the machined product 203 can also include the following steps.

[0078] (1) a step of rotating the rotary cutter 1 represented by the above-mentioned non-limiting embodiment;

[0079] (2) a step of bringing the rotating rotary tool 1 into contact with the workpiece 201; and

[0080] (3) A step of separating the rotary tool 1 from the workpiece 201 .

[0081] Specifically, first, Figure 14 As shown in the non-limiting example, the rotary tool 1 can be relatively brought close to the workpiece 201 while rotating about the rotation axis O1 in the Y1 direction. Figure 15 As shown in the non-limiting example, the upper cutting edge 15 of the rotary cutter 1 can be brought into contact with the workpiece 201 to cut the workpiece 201. Figure 16 As in the illustrated non-limiting example, the rotary tool 1 may be relatively separated from the workpiece 201 .

[0082] By going through the above steps, excellent machinability can be achieved. Specifically, in the method for producing a machined product 203 according to one aspect of the present disclosure, which is not limited thereto, when using the rotary tool 1, the side surface 13 of the blade 5 is prevented from contacting the workpiece 201, and the machinability is high. Consequently, a machined product 203 with a highly accurate finished surface can be obtained.

[0083] In addition, Figures 14 to 16 In the non-limiting example shown, the workpiece 201 is fixed and the rotary tool 1 is moved in each step, but the present invention is not limited to this embodiment.

[0084] For example, in step (1), the workpiece 201 may be brought closer to the rotary tool 1. Similarly, in step (3), the workpiece 201 may be moved away from the rotary tool 1. While the cutting process is continued, the process of bringing the upper cutting edge 15 of the blade 5 into contact with different portions of the workpiece 201 may be repeated while the rotary tool 1 is kept rotating.

[0085] Examples of the material of the workpiece 201 include carbon steel, alloy steel, stainless steel, cast iron, and non-ferrous metals.

[0086] Description of Reference Numerals

[0087] 1…Rotary tool

[0088] 1a..Backend

[0089] 1b..Front End

[0090] 3...Handle

[0091] 5...Cutting blades (blades)

[0092] 7...Knife groove

[0093] 9...Upper surface

[0094] 11...lower surface

[0095] 13...Side

[0096] 15...Upper cutting edge

[0097] 17...Lower cutting edge

[0098] 19...First top

[0099] 19a..First end

[0100] 19b..Third end

[0101] 21...first bottom

[0102] 21a..Second end

[0103] 21b..The fourth end

[0104] 23...First side

[0105] 25...Second side

[0106] 27...The third side

[0107] 29...front area

[0108] 31...upper inclined surface

[0109] 33...Upper flat surface

[0110] 33a..Fifth End

[0111] 35...lower slope

[0112] 37...lower flat surface

[0113] 37a..Sixth End

[0114] 39...Through hole

[0115] 41...screws

[0116] 201...Working parts

[0117] 203...Cutting workpiece

[0118] O1...rotation axis

[0119] O2...Central axis.

Claims

1. A rotary cutter extending from a rear end to a front end along a rotation axis, wherein: The rotary cutter has: a tool handle in a cylindrical shape extending along the rotation axis and having a tool groove located on the front end side; a cutting insert located in the tool groove, The cutting insert has: an upper surface located forward in the rotational direction of the rotating shaft and having a first upper side located on the front end side; a lower surface located on an opposite side of the upper surface and having a first lower side located on the front end side; a side surface located between the upper surface and the lower surface; an upper cutting edge located on the first upper side; as well as a lower cutting edge, which is located at said first lower side, The side has: a first side surface located at the front end side; a second side surface located on the outer peripheral side of the handle; as well as a third side surface, which is located on the opposite side of the second side surface, The first upper side is convex and protrudes toward the front end, and has a first end located on the front end side. The first end is located closer to the third side surface than the second side surface, The first lower side is convex and protrudes toward the front end, and has a second end located on the front end side. The second end is located closer to the second side surface than to the third side surface, When observing the upper surface from a front view, the first side surface has a front end region sandwiched by the first end and the second end, and the front end region is recessed toward the rear end. When observing the first side from the front view, The first upper side is convex and protrudes upward, and has a third end located farthest from the lower surface. The third end is located directly above the second end.

2. The rotary cutter according to claim 1, wherein When observing the upper surface from a front view, a cross section passing through the first end and perpendicular to the first upper side is a first cross section. In the first cross section, the side surface is concave.

3. The rotary cutter according to claim 1 or 2, wherein: When observing the upper surface from a front view, a cross section passing through the second end and perpendicular to the first lower side is a second cross section. In the second cross section, the side surface is concave.

4. The rotary cutter according to claim 1 or 2, wherein: When observing the first side from the front view, The first lower side is convex and protrudes downward, and has a fourth end located farthest from the upper surface. The fourth end is located directly below the first end.

5. The rotary cutter according to claim 1 or 2, wherein: The upper surface has: an upper inclined surface located along the upper cutting edge and approaching the lower surface as it moves away from the upper cutting edge; and a flat upper flat surface located closer to the center of the upper surface than the upper inclined surface, The upper flat surface has a fifth end located on the front end side, The fifth end is located closer to the third side surface than to the second side surface. The rotary cutter according to claim 5 , wherein: The third side surface is located closer to the fifth end than to the first end.

7. The rotary cutter according to claim 1 or 2, wherein: The lower surface has: a lower inclined surface located along the lower cutting edge and approaching the upper surface as it moves away from the lower cutting edge; and a flat lower flat surface located closer to the center of the lower surface than the lower inclined surface, The lower flat surface has a sixth end located on the front end side, The sixth end is located closer to the second side surface than to the third side surface.

8. The rotary cutter according to claim 7, wherein: The second side surface is located closer to the sixth end than to the second end.

9. A method for producing a machined product, wherein: The method for manufacturing the machined product comprises: The step of rotating the rotary cutter according to any one of claims 1 to 8; a step of bringing the rotating rotary tool into contact with a workpiece; and a step of separating the rotary cutter from the workpiece.

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