Cutting tool and method for manufacturing machined product

Abstract

A cutting tool according to one embodiment of the present invention comprises: a body which extends, along a rotational axis thereof, from a leading end thereof toward a rear end thereof and which has a pocket disposed on the leading-end side; and a cutting part which is disposed in the pocket. The cutting part has: a leading-end surface; a front-side surface; an outer-side surface; an inner-side surface located on the side opposite to the outer-side surface; and a cutting edge disposed at the intersection between the leading-end surface and the front-side surface. The leading-end surface has formed therein a slit which is located rearward of the cutting edge in the rotational direction so as to extend toward the rear end. The slit is opened in the outer-side surface and the inner-side surface and is tilted so as to separate away from the front-side surface as the rear end becomes closer.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to Japanese Patent Application No. 2022-001788, filed on January 7, 2022, the entire disclosure of which is incorporated herein by reference. [Technical Field]

[0002] The present disclosure relates to a cutting tool and a method for manufacturing a machined product. An example of a cutting tool is a so-called milling tool. The milling tool can be used for milling processes such as face milling and end milling. [Background technology]

[0003] Known cutting tools include milling tools described in, for example, International Publication No. 2013 / 029072 (Patent Document 1), International Publication No. 2004 / 080633 (Patent Document 2), and Japanese Patent Application Laid-Open No. 2005-111651 (Patent Document 3). Generally, when face milling is performed using a milling tool, there is a risk of iris patterns being produced on the machined surface of the workpiece due to the cutting edge coming into contact with the workpiece at the rear in the feed direction.

[0004] In the milling tools described in Patent Documents 1 and 2, the rotation axis of the milling tool is inclined forward in the feed direction. This avoids the risk of iris lattice patterns appearing on the machined surface of the workpiece. In the milling tool described in Patent Document 3, a relief portion is provided for the wiper blade in the direction along the rotation axis. This avoids the risk of iris lattice patterns appearing on the machined surface of the workpiece due to the relief portion.

[0005] However, as described in Patent Documents 1 and 2, tilting the rotation axis forward in the feed direction is possible in machines in which the machining direction is limited to one axis, such as general-purpose milling cutters, but is difficult to introduce into general machining centers and the like in which the machining direction is more than one axis. In other words, the milling tools described in Patent Documents 1 and 2 lack versatility.

[0006] Furthermore, in the milling tool described in Patent Document 3, the wiper blade positioned at the front in the feed direction and the wiper blade positioned at the rear in the feed direction are positioned at the same position along the rotation axis. Therefore, the risk of iris patterns caused by the relief portion is avoided, but the risk of iris patterns caused by the wiper blade is not avoided. Summary of the Invention

[0007] A cutting tool according to one aspect of the present disclosure includes a body portion extending from a tip to a rear end along a rotation axis and having a pocket located on the tip side, and a cutting portion located in the pocket. The cutting portion has a tip surface located on the tip side, a front side surface connected to the tip surface and located forward in the rotation direction of the rotation axis, an outer side surface connected to the tip surface and the front side surface and located radially outward of the rotation axis, an inner side surface located opposite the outer side surface, and a cutting edge located at an intersection of the tip surface and the front side surface. The tip surface has a slit located rearward of the cutting edge in the rotation direction and extending toward the rear end. The slit opens to the outer side surface and the inner side surface and is inclined away from the front side surface as it approaches the rear end. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a perspective view showing a cutting tool according to an embodiment. [Figure 2] FIG. 2 is a plan view of the cutting tool shown in FIG. 1 as viewed from the A1 direction. [Figure 3] 2 is a plan view of the cutting tool shown in FIG. 1 as viewed from the A2 direction. [Figure 4] 2 is a perspective view of a first cutting portion and a fixture of the cutting tool shown in FIG. 1, seen from the rear end side. FIG. [Figure 5] 2 is a perspective view of the first cutting portion and the fixture of the cutting tool shown in FIG. 1, seen from the tip side. FIG. [Figure 6] FIG. 5 is a plan view of the area shown in FIG. 4 as viewed from the A3 direction. [Figure 7]FIG. 5 is a plan view of the area shown in FIG. 4 as viewed from the A4 direction. [Figure 8] 5 is a plan view of the part shown in FIG. 4 as seen from the A5 direction, showing the state during cutting. FIG. [Figure 9] FIG. 9 is a diagram showing the state of the part shown in FIG. 8 when not being cut. [Figure 10] FIG. 4 is an enlarged view of the cross section XX shown in FIG. [Figure 11] FIG. 2 is a schematic explanatory view showing one step of a method for manufacturing a machined product according to one embodiment. [Figure 12] FIG. 2 is a schematic explanatory view showing one step of a method for manufacturing a machined product according to one embodiment. [Figure 13] FIG. 2 is a schematic explanatory view showing one step of a method for manufacturing a machined product according to one embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] A cutting tool 1 according to a non-limiting embodiment of the present disclosure will be described in detail below with reference to the drawings. However, for the sake of convenience, the drawings referred to below show simplified views of only the main components necessary for explaining each embodiment. Therefore, the cutting tool 1 according to the present disclosure may include optional components not shown in the drawings. Furthermore, the dimensions of the components in the drawings do not faithfully represent the actual dimensions of the components or the dimensional ratios of each component. During the cutting process, "cutting" refers to a state in which the cutting tool 1 is in contact with the workpiece, and "non-cutting" refers to a state in which the cutting tool 1 is not in contact with the workpiece. Furthermore, unless otherwise noted, the drawings will depict the state of the cutting tool 1 when not cutting.

[0010] The cutting tool 1 according to the embodiment has a rotation axis O1, as shown in a non-limiting example in FIG. 1 , and is a so-called rotary tool. Examples of rotary tools include milling tools and end mills. The non-limiting example of the rotary tool shown in FIG. 1 is a milling tool. Note that the rotation axis O1 is an axis about which the cutting tool 1 rotates, and is not a tangible object that the cutting tool 1 has.

[0011] As a non-limiting example shown in FIG. 2 and other figures, the cutting tool 1 includes a main body 3 and a cutting portion 5. The main body 3 extends from a front end 3A to a rear end 3B along a rotation axis O1. FIG. 2 is a side view of the cutting tool 1 shown in FIG. 1 as viewed from the A1 direction. The main body 3 has an insert pocket (pocket 7) located on the front end 3A side. The cutting portion 5 is located in the pocket 7 and has a cutting edge 9 located on the front end 3A side (see FIG. 1 and other figures).

[0012] The main body 3 is the base of the cutting tool 1. The pocket 7 may be open on the outer peripheral surface of the main body 3 and on the end surface on the tip 3A side. There may be only one pocket 7, or there may be multiple pockets 7 as shown in the non-limiting example of FIG. 1. When the main body 3 has multiple pockets 7, one of the multiple pockets 7 is referred to as the first pocket 7A. The number of cutting portions 5 is not limited to one, and may be multiple as shown in the non-limiting example of FIG. 1. When the main body 3 has multiple pockets 7, the cutting portion 5 located in the first pocket 7A is referred to as the first cutting portion 5A.

[0013] The cutting tool 1 is rotatable counterclockwise about a rotation axis O1 when viewed from the tip 3A side, as in a non-limiting example shown in Figure 3. This rotation direction O2 is not limited to the direction shown in Figure 3. For example, if the cutting tool 1 has a configuration that is inverted around the rotation axis O1 relative to the configuration shown in Figure 1, the rotation direction O2 may be the opposite direction. Note that Figure 3 is a view of the cutting tool 1 shown in Figure 1 as viewed from the A2 direction (the tip 3A side).

[0014] In a non-limiting example shown in FIG. 1 , the cutting tool 1 of the embodiment has a substantially disk-like shape extending from the leading end 3A to the rear end 3B along the rotation axis O1. For ease of explanation, the portions of the main body 3 located on the leading end 3A side and the rear end 3B side may be referred to as the first end 3A and the second end 3B, respectively. As is clear from the fact that the cutting tool 1 has a first pocket 7A and the like, the cutting tool 1 is not strictly disk-like. The length of the main body 3 in the direction along the rotation axis O1 is, for example, 50 mm to 100 mm. The length of the main body 3 in the radial direction of the rotation axis O1 is, for example, 100 mm to 300 mm.

[0015] The main body 3 can rotate around a rotation axis O1. There are no particular limitations on the shape of the main body 3, and it may have irregularities or the like. The main body 3 may be made of a single member, as shown in the non-limiting example of FIG. 1, or may be made of multiple members.

[0016] A cutting part 5 may be attached to each pocket 7. As a non-limiting example shown in FIG. 3, a cutting part 5 may also be attached to multiple pockets 7 other than the first pocket 7A. The first pocket 7A may be connected to pockets 7 other than the first pocket 7A. Furthermore, the first pocket 7A may be located closer to the rotation axis O1 than the pockets 7 other than the first pocket 7A.

[0017] The cutting unit 5 may be composed of one member or multiple members. For example, the cutting unit 5 may have a cutting insert (insert 11) and a cartridge 13. Here, when the first cutting unit 5A has the insert 11 and the cartridge 13, the insert 11 in the first cutting unit 5A is referred to as a first insert 11A, and the cartridge 13 in the first cutting unit 5A is referred to as a first cartridge 13A.

[0018] The first cutting portion 5A located in the first pocket 7A has a cutting edge 9 located on the side of the first end 3A. In a non-limiting example shown in Fig. 4, the first insert 11A has the cutting edge 9. A machined product can be produced by cutting a workpiece with this cutting edge 9.

[0019] The cutting edge 9 is located forward of the first insert 11A in the rotational direction O2 and on the first end 3A side. Specifically, the cutting edge 9 is located at the intersection of a tip end face 19 and a front side face 23, which will be described later. The cutting edge 9 may be located over the entire intersection, or may be located only on a portion of the intersection. The cutting edge 9 does not have to be located only on this portion. For example, if the cutting edge 9 located forward of the first insert 11A in the rotational direction O2 and on the first end 3A side is defined as the first cutting edge 15, the first insert 11A may further include a second cutting edge 17 located forward of the first insert 11A in the rotational direction O2 and on the outer periphery side.

[0020] The first cutting edge 15 protrudes from the main body 3 and is located on the first end 3A side. The second cutting edge 17 may also protrude further outward than the main body 3. Generally, the first cutting edge 15 located on the first end 3A side is called an end edge, and the second cutting edge 17 located on the outer periphery side is called an outer edge edge.

[0021] The first cutting edge 15 and the second cutting edge 17 may be located on the outer periphery of the cutting insert 11. The first cutting edge 15 and the second cutting edge 17 are not limited to a linear shape, and may be a gently curved shape.

[0022] The first insert 11A is located on the first end 3A side and forward in the rotational direction O2 with respect to the first cartridge 13A. The first insert 11A may be fixed to the first cartridge 13A using a screw or the like, as shown in a non-limiting example in FIG.

[0023] The first cutting portion 5A may have a rectangular plate shape, as shown in a non-limiting example in FIG. 4. Here, as shown in a non-limiting example in FIG. 3, the first cutting portion 5A may have a rectangular shape when viewed from the first end 3A side. In the non-limiting example shown in FIG. 3, the first cutting portion 5A is attached so that its short side is in the radial direction of the rotation axis O1 and its long side is in the circumferential direction of the rotation axis O1. The length of the first cutting portion 5A in the direction along the rotation axis O1 is, for example, 4 mm to 7 mm. The length of the first cutting portion 5A in the radial direction of the rotation axis O1, i.e., the short side mentioned above, is, for example, 12 mm to 15 mm. The length of the first cutting portion 5A in the circumferential direction of the rotation axis O1, i.e., the long side mentioned above, is, for example, 30 mm to 40 mm.

[0024] The first cutting portion 5A has a tip surface 19. The tip surface 19 is a surface of the first cutting portion 5A that is located on the side of the first end 3A. The tip surface 19 may be made of a single member, or may be made of multiple members as in the non-limiting example shown in FIG. 7.

[0025] For example, as shown in a non-limiting example in Figure 7, the tip surface 19 may be configured by a surface located on the side of the first end 3A in the rotational direction O2 of the first insert 11A and the first cartridge 13A. There are no particular limitations on the shape of the tip surface 19, and it may be, for example, a flat or curved shape, or may have an uneven portion. In the non-limiting example shown in Figure 3, the tip surface 19 is rectangular in shape, as described above.

[0026] The first cutting portion 5A may have a rear end surface 21. The rear end surface 21 is a surface of the first cutting portion 5A that is located on the side of the second end 3B. There are no particular limitations on the shape of the rear end surface 21, and it may be, for example, a flat or curved shape, or may have an uneven portion.

[0027] The first cutting portion 5A has a front side surface 23. The front side surface 23 is a surface connected to the tip surface 19 and is a surface located forward in the rotational direction O2 of the first cutting portion 5A. The front side surface 23 may be formed of a single member, or may be formed of multiple members as in the non-limiting example shown in FIG. 6. For example, as in the non-limiting example shown in FIG. 6, the front side surface 23 may be formed by a surface located forward in the rotational direction O2 of the first insert 11A and the first cartridge 13A. There are no particular limitations on the shape of the front side surface 23; for example, it may be flat or curved, and it may have uneven portions.

[0028] The front side surface 23 may have a first side 25, a second side 27, and a first corner 29. The first side 25 may be located on the side of the first end 3A. The second side 27 may be located on the outer periphery side away from the rotation axis O1. The first corner 29 is a corner connected to the first side 25 and the second side 27. Note that the corner here is not limited to a point where two sides intersect, but may be a region where two sides intersect macroscopically, and may be a curved shape or a linear shape inclined with respect to each of the two sides microscopically.

[0029] The first cutting edge 15 may be located on the first side 25. As described above, since the first side 25 is located on the side of the first end 3A, the first cutting edge 15 located on the first side 25 can be located on the side of the first end 3A in the first cutting portion 5A. Furthermore, the second cutting edge 17 may be located on the second side 27. As described above, since the second side 27 is located on the outer periphery side, the second cutting edge 17 located on the second side 27 can be located on the outer periphery side in the first cutting portion 5A.

[0030] The first cutting portion 5A may have a third cutting edge 31 located at the first corner 29. The third cutting edge 31 may be connected to the first cutting edge 15 and the second cutting edge 17. The third cutting edge 31 is not limited to a curved shape, and may have a linear portion or may be arc-shaped.

[0031] The first cutting portion 5A has an outer surface 33. The outer surface 33 is a surface that is connected to the tip surface 19 and the front surface 23. The outer surface 33 is located radially outward from the rotation axis O1, i.e., on the outer peripheral side of the first cutting portion 5A. The outer surface 33 may be formed of a single member or may be formed of multiple members. There are no particular limitations on the shape of the outer surface 33; for example, it may be flat or curved, and may have uneven portions.

[0032] The first cutting portion 5A has an inner surface 35. The inner surface 35 is located on the opposite side of the outer surface 33. The inner surface 35 may be a surface connected to the tip surface 19 and the front surface 23. The inner surface 35 may be made of a single member or may be made of multiple members. There are no particular limitations on the shape of the inner surface 35, and it may be, for example, a flat or curved shape, or may have uneven portions.

[0033] The tip surface 19 has a slit 37. Specifically, the first cutting part 5A has the slit 37 that opens at the tip surface 19. The slit 37 is located rearward of the first cutting edge 15 (cutting edge 9) in the rotational direction O2. The slit 37 also extends toward the second end 3B.

[0034] The slits 37 are open to the outer surface 33 and the inner surface 35. As a non-limiting example shown in Fig. 3, the slits 37 may extend in the radial direction of the rotation axis O1. Alternatively, as a non-limiting example shown in Fig. 9, the slits 37 may be inclined so as to move away from the front surface 23 toward the second end 3B.

[0035] As a non-limiting example shown in Fig. 10, the slit 37 may be inclined rearward in the rotational direction O2 toward the second end 3B in a cross section parallel to the rotation axis O1. Fig. 10 is a cross section taken along line XX of the portion shown in Fig. 3. The XX cross section passes through the center of the first insert 11A and is parallel to the rotation axis O1.

[0036] In a non-limiting example shown in FIG. 11, when cutting a workpiece, cutting tool 1 rotates around rotation axis O1 while moving in a predetermined direction (the so-called feed direction). First cutting portion 5A can contribute to the cutting process when positioned forward in the feed direction relative to rotation axis O1. On the other hand, when first cutting portion 5A is positioned backward in the feed direction relative to rotation axis O1, it does not contribute to the cutting process. This avoids the risk of iris pattern formation, which occurs when first cutting portion 5A comes into contact with the workpiece when positioned backward in the feed direction relative to rotation axis O1.

[0037] When the first cutting portion 5A comes into contact with the workpiece during cutting, a cutting load is likely to be applied from the workpiece to the first cutting portion 5A in the direction toward the workpiece. Therefore, the first cutting portion 5A elastically deforms in the direction narrowing the width of the slit 37 provided in the first cutting portion 5A, and the portion of the first cutting portion 5A located forward of the slit 37 in the rotational direction O2 moves toward the workpiece. As a result, the first cutting edge 15 bites into the workpiece, and cutting is performed. At this time, the position of the first cutting edge 15 during cutting is referred to as the first cutting edge position S1 (see FIG. 8). Note that FIG. 8 shows the state of the first cutting portion 5A and other components shown in FIG. 4 during cutting.

[0038] Furthermore, when the first cutting part 5A is positioned rearward in the feed direction relative to the rotation axis O1, the elastically deformed first cutting part 5A returns to its original state. That is, the first cutting edge 15 moves in a direction toward the second end 3B relative to the first cutting edge position S1. Therefore, compared to when the first cutting part 5A is positioned forward in the feed direction relative to the rotation axis O1, when the first cutting part 5A is positioned rearward in the feed direction relative to the rotation axis O1, the first cutting edge 15 is positioned closer to the second end 3B.

[0039] At this time, the position of the first cutting edge 15 when not cutting is defined as a second cutting edge position S2 (see FIG. 9). Note that FIG. 9 corresponds to FIG. 8 and shows the state of the first cutting part 5A etc. shown in FIG. 4 when not cutting. The difference (ΔZ) between the first cutting edge position S1 and the second cutting edge position S2 in the direction along the rotation axis O1 is, for example, 0.05 mm to 0.2 mm.

[0040] When the first cutting portion 5A is positioned rearward in the feed direction relative to the rotation axis O1, the first cutting edge 15 is positioned closer to the second end 3B, making it less likely that the first cutting portion 5A will come into contact with the workpiece, compared to when the first cutting portion 5A is positioned forward in the feed direction relative to the rotation axis O1.

[0041] The above-mentioned effects reduce the risk of iris patterns. In addition, the above-mentioned cutting process can be performed without tilting the rotation axis O1 of the cutting tool 1 forward in the feed direction, so the cutting direction is not limited to one direction and the tool travel distance can be reduced. Therefore, the above-mentioned effects are highly versatile and contribute to shortening the processing time.

[0042] Furthermore, the slit 37 does not necessarily need to tilt away from the front side surface 23 as it moves toward the second end 3B, and may have a portion that tilts slightly toward the front side surface 23 or a portion that is parallel to the rotation axis O1 within the range that achieves the above-mentioned effect.

[0043] The interior of the slit 37 is not limited to a void. For example, the interior of the slit 37 may be filled with resin, rubber, or the like. Examples of resin include polycarbonate resin, polyethylene terephthalate resin, acrylic resin, polyvinyl chloride resin, silicone resin, and epoxy resin. Examples of rubber include natural rubber and synthetic rubber.

[0044] The slit 37 may have a bottom 39 located on the second end 3B side, and a pair of inner wall surfaces 41 connected to the bottom 39. As a non-limiting example shown in FIG. 8, the bottom 39 may be circular when viewed from the side. When the bottom 39 is circular in this way, the risk of stress concentration on the bottom 39 of the slit 37 can be reduced. The pair of inner wall surfaces 41 may each be flat, or may be parallel to each other.

[0045] 8, in the direction in which the rotation axis O1 extends, the length L1 from the tip surface 19 to the bottom 39 of the slit 37 is longer than the length L2 from the bottom 39 of the slit 37 to the rear end surface 21 of the first cutting portion 5A. The ratio L1 / L2 of the lengths L1 and L2 may be, for example, 4 to 20. In such a case, the portion from the bottom 39 of the slit 37 to the rear end surface 21 of the first cutting portion 5A does not become too thin, so the durability of the first cutting portion 5A is maintained, and at the same time, the portion from the bottom 39 of the slit 37 to the rear end surface 21 of the first cutting portion 5A does not become too thick, so the first cutting portion 5A can smoothly elastically deform during cutting.

[0046] When viewed from the first end 3A side, the direction in which the slit 37 extends is not particularly limited. For example, as shown in a non-limiting example in FIG. 7, the slit 37 may be parallel to the first cutting edge 15 (cutting edge 9) when viewed from the first end 3A side (when viewed from the tip). In such a case, the direction of the principal component of the cutting load and the direction of elastic deformation of the first cutting portion 5A when viewed from the first end 3A side coincide with each other, allowing the first cutting portion 5A to smoothly elastically deform. Note that "parallel" here does not necessarily mean that the angle between the slit 37 and the first cutting edge 15 is 0°, but may also include a deviation of approximately 1° to 2°.

[0047] In a non-limiting example shown in FIG. 1 , the first insert 11A is a so-called wiper insert. That is, the inserts 11 other than the first insert 11A of the cutting portions 5 other than the first cutting portion 5A are used for normal milling of the workpiece, while the first insert 11A is a finishing insert 11 for improving the surface precision of the machined surface of the workpiece. In this case, the first insert 11A protrudes more toward the first end 3A than the cutting inserts 11 other than the first insert 11A. Note that in a non-limiting example shown in FIG. 3 , the first cutting portion 5A is located more inwardly than the cutting portions 5 other than the first cutting portion 5A.

[0048] In a non-limiting example shown in Figure 3, first cutting portion 5A is located in first pocket 7A in which first insert 11A, which is a wiper insert, is attached, but is not located in outer pocket 7 in which insert 11 for normal milling is attached. In such a case, cutting tool 1 can have the minimum number of cutting portions 5 necessary while reducing the risk of iris patterning. In other words, the number of cutting portions 5 having complex structures such as slits 37 can be minimized, reducing the risk of iris patterning and reducing the manufacturing cost of cutting tool 1.

[0049] The cutting tool 1 may have a fixing device 43. In a non-limiting example shown in Fig. 1, the fixing device 43 is used to fix the first cutting part 5A to the main body part 3. An example of the fixing device 43 is a screw.

[0050] 7, the fixing device 43 is located behind the slit 37 in the rotational direction O2. In this case, the cutting portion 5 can be stably fixed to the main body 3 without interfering with the elastic deformation of the first cutting portion 5A. Note that, here, "behind the rotational direction O2" is not particularly limited in terms of its positional relationship in the direction in which the rotation axis O1 extends, and the fixing device 43 does not necessarily have to be located behind the slit 37.

[0051] When viewed from the first end 3A (when viewed from the tip), the distance W1 between the fixture 43 and the slit 37 may be greater than the distance W2 between the slit 37 and the first cutting edge 15 (cutting edge 9). In this case, the fixture 43 is less susceptible to the elastic deformation of the first cutting portion 5A that occurs when cutting and non-cutting are repeated, so the first cutting portion 5A can be stably fixed. As shown in FIG. 7, the above distances may be evaluated as the distance W1 between the center P1 of the fixture 43 and the center line P2 of the slit 37 and the distance W2 between the center P3 of the first cutting edge 15 and the center line P2 of the slit 37 in the circumferential direction of the rotational direction O2.

[0052] The first cutting part 5A may have an adjustment member 45 that can adjust the amount of elastic deformation of the slit 37. The adjustment member 45 may have an end 47, and as shown in a non-limiting example in FIG. 9 , the end 47 may be located within the slit 37. In such a case, when the first cutting part 5A elastically deforms during cutting, the portion of the first cutting part 5A located on the front side surface 23 side comes into contact with the adjustment member 45, thereby preventing the first cutting edge 15 from excessively protruding toward the first end 3A, and making it possible to adjust the position of the first cutting edge 15 (first cutting edge position S1).

[0053] The adjustment member 45 may be in the form of a screw, and may have a screw head 49 as shown in a non-limiting example in Figure 7. In such a case, the position of the end 47 located within the slit 37 can be adjusted by tightening the screw, and the position of the first cutting edge 15 can be adjusted.

[0054] 7, the screw head 49 may face the first end 3A side. In this case, the adjustment member 45 can be adjusted from the first end 3A side, and the position of the first cutting edge 15 can be adjusted without removing the first cutting portion 5A from the cutting tool 1, improving operability.

[0055] 9, the end 47 of the adjustment member 45 located on the front side in the rotational direction O2 is located inside the slit 37, but the end 47 located on the rear side in the rotational direction O2 may also be located inside the slit 37. In such a case, the screw head 49 may face the second end 3B side.

[0056] The end 47 may be located closer to the opening in the tip surface 19 than the bottom 39 of the slit 37. In such a case, the end 47 is more likely to be located closer to the first end 3A, allowing for more precise position adjustment of the first cutting edge 15. Here, being located closer to the opening in the tip surface 19 than the bottom 39 of the slit 37 means that when the length from the opening of the slit 37 to the portion of the bottom 39 on the rear end surface 21 side is bisected, as in the non-limiting example shown in FIG. 9 , the end 47 is located closer to the first end 3A than the bisector N1.

[0057] As a non-limiting example shown in FIG. 7 , the adjustment member 45 may be located closer to the outer surface 33 than to the inner surface 35. Normally, during cutting, a cutting load is more likely to be applied to the side closer to the outer surface 33 than to the inner surface 35, so the first cutting portion 5A experiences a larger amount of elastic deformation on the outer surface 33 side. Therefore, with the above-described configuration, the adjustment member 45 can withstand the cutting load. This improves the durability of the slit 37 and also improves the positional accuracy of the first cutting edge 15.

[0058] The shape of the end portion 47 is not particularly limited. For example, the end portion 47 may be flat. In such a case, the inner wall surface 41 and the end portion 47 can be in stable contact with each other, so that the position of the first cutting edge 15 is stably maintained. Note that the flat shape here is not necessarily limited to a flat shape, and may be a slightly convex or concave shape.

[0059] The adjustment member 45 may be located behind the slit 37, as in the non-limiting example shown in Fig. 7. Here, "behind the slit 37" does not mean that the entire adjustment member 45 needs to be located behind the slit 37, and as in the non-limiting example shown in Fig. 7, a part of the adjustment member 45, such as the end portion 47, may be located within the slit 37.

[0060] 9, the central axis L1 of the adjustment member 45 may extend perpendicular to the slit 37. Here, "extending perpendicularly" means that the central axis L1 of the adjustment member 45 is perpendicular to the pair of inner wall surfaces 41 of the slit 37. If it is difficult to evaluate the above relationship when viewed from the outer surface 33 side, the evaluation may be performed on a cross section including the adjustment member 45 and the slit 37.

[0061] In the above case, the end 47 can stably contact the portion of the first cutting part 5A located on the front side surface 23 side, thereby stably maintaining the position of the first cutting edge 15. Note that "perpendicular" here does not necessarily mean that the angle between the central axis L1 of the adjustment member 45 and the direction in which the slit 37 extends is 90°, and may include a deviation of about 1° to 2°.

[0062] The main body 3 may have a first coolant hole 51. The first coolant hole 51 may extend from the second end 3B toward the first end 3A. Alternatively, the first coolant hole 51 may extend from the second end 3B side toward the first end 3A side. The first coolant hole 51 may have multiple branches. The first coolant hole 51 allows coolant to flow inside.

[0063] The first cartridge 13A may have a second coolant hole 53. The second coolant hole 53 may extend from the second end 3B toward the first end 3A. Alternatively, the second coolant hole 53 may extend from the second end 3B side toward the first end 3A side. The second coolant hole 53 is connected to the first coolant hole 51 on the second end 3B side. The second coolant hole 53 may have multiple branches. The second coolant hole 53 allows coolant to flow inside.

[0064] The second coolant holes 53 may extend along a surface located on the rear end surface 21 side of the first insert 11A and may open at the front side surface 23 as shown in a non-limiting example in FIG. 6. That is, the second coolant holes 53 may open toward the upper surface of the first insert 11A. In this case, coolant can be made to flow in a fixed direction toward the chips from the second end 3B side, allowing the chips to be stably discharged.

[0065] The second coolant hole 53 may be located forward of the slit 37 in the rotational direction O2, as shown in a non-limiting example in FIG. 10 . That is, in a cross section perpendicular to the cutting edge 9, the second coolant hole 53 may be located forward of the slit 37 in the rotational direction O2. In this case, the second coolant hole 53 can be located in the first cutting portion 5A, away from the slit 37, which is likely to be subjected to load during cutting, thereby reducing the risk of deformation of the second coolant hole 53. Here, "forward of the rotational direction O2" is not particularly limited in terms of its position in the direction in which the rotation axis O1 extends, and the second coolant hole 53 does not necessarily have to be located directly in front of the slit 37.

[0066] Examples of coolants include water-insoluble oils and water-soluble oils. Examples of water-insoluble oils include cutting oils such as oil-based, inactive extreme pressure, and active extreme pressure types. Examples of water-soluble oils include cutting oils such as emulsions, solubles, and solutions. The coolant is not limited to a liquid, and may be a gas such as an inert gas. The coolant may be selected appropriately depending on the material of the workpiece.

[0067] <Method for manufacturing machined products> Next, a method for manufacturing a machined product according to an unrestricted embodiment of the present disclosure will be described in detail using the cutting tool 1 according to the unrestricted embodiment described above as an example. The description will be made below with reference to FIGS. 11 to 13. Note that FIGS. 11 to 13 illustrate the steps of cutting a workpiece 102 as an unrestricted example of a method for manufacturing a machined product 101. The method for manufacturing a machined product 101 according to an unrestricted embodiment of the present disclosure may include the following steps (1) to (3).

[0068] (1) The cutting tool 1 is rotated about the rotation axis O1 in a rotation direction O2, and the cutting tool 1 is brought closer to the workpiece 102 in a feed direction Y1 (see FIG. 11 ). This step can be performed, for example, by fixing the workpiece 102 on a table of a machine tool to which the cutting tool 1 is attached, and bringing the cutting tool 1 closer to the workpiece 102 while rotating. Note that in this step, it is sufficient that the workpiece 102 and the cutting tool 1 are relatively close to each other, and the workpiece 102 may be brought closer to the cutting tool 1.

[0069] (2) By bringing the cutting tool 1 even closer to the workpiece 102, the rotating cutting tool 1 is brought into contact with the desired position on the surface of the workpiece 102, thereby cutting the workpiece 102 (see FIG. 12). In this step, the cutting blade 9 is brought into contact with the desired position on the surface of the workpiece 102.

[0070] (3) The cutting tool 1 is moved away from the workpiece 102 in the Y2 direction (see FIG. 13). In this step, similar to the step (1) described above, the cutting tool 1 may be moved relatively away from the workpiece 102, and for example, the workpiece 102 may be moved away from the cutting tool 1. Note that, in addition to the milling process shown in FIG. 13 as a non-limiting example, examples of cutting processes include plunge milling, copy milling, and oblique submersion milling.

[0071] By going through the steps as described above, it is possible to exhibit excellent workability. When cutting the workpiece 102 as described above is performed multiple times, for example, when performing multiple cutting operations on one workpiece 102, the step of bringing the cutting tool 1 into contact with different locations on the workpiece 102 while maintaining the cutting tool 1 in a rotating state may be repeated.

[0072] Examples of materials for the workpiece 102 include carbon steel, alloy steel, stainless steel, cast iron, and non-ferrous metals. [Explanation of symbols]

[0073] 1...cutting tools 3. Main body 3A...Tip (1st end) 3B...Rear end (2nd end) 5...Cutting part 5A...1st cutting section 7 pockets 7A First pocket 9 Cutting edge 11 Insert 11A···First insert 13 Cartridge 13A···First cartridge 15···First cutting edge 17···Second cutting edge 19...Tip surface 21...Rear end surface 23 Front side 25...First side 27...Second side 29 First corner 31···Third cutting edge 33...outer surface 35...Inner surface 37. Slit 39...Bottom 41...Inner wall surface 43...fixture 45 Adjustment member 47 End 49···Screw head 51···First coolant hole 53 Second coolant hole 101...Cutting workpiece 102...Work material O1 Rotation axis O2 Rotation direction Y1: Feed direction L1, L2...length S1: First cutting edge position S2: Second cutting edge position W1, W2 spacing P1, P2, P3...center (line) N1...bisector L1...center axis

Claims

1. a main body portion extending from a front end to a rear end along a rotation axis and having a pocket located on the front end side; a cutting portion located in the pocket, The cutting portion is a tip surface located on the tip side; a front side surface connected to the tip surface and positioned forward in the rotation direction of the rotation shaft; an outer surface connected to the tip surface and the front surface and positioned radially outward of the rotation shaft; an inner surface opposite the outer surface; a cutting edge located at an intersection of the tip surface and the front side surface, the tip end surface is located rearward of the cutting blade in the rotation direction and has a slit extending toward the rear end, The slit is open to the outer surface and the inner surface, and is inclined away from the front surface toward the rear end.

2. The cutting tool according to claim 1 , wherein the slit is parallel to the cutting edge when viewed from the tip.

3. the cutting tool has a fixture that fixes the cutting part to the body part, The cutting tool according to claim 1 , wherein the fixture is located rearward of the slit in the direction of rotation.

4. The cutting tool according to claim 3 , wherein, when viewed from the tip, a distance between the fixing member and the slit is larger than a distance between the slit and the cutting edge.

5. the cutting portion has an adjustment member capable of adjusting an amount of elastic deformation of the slit, The cutting tool of claim 1 , wherein the adjustment member has an end located within the slit.

6. The cutting tool according to claim 5 , wherein the end of the adjustment member is located closer to the opening in the tip surface than to a bottom of the slit.

7. The cutting tool of claim 5 , wherein the adjustment member is located closer to the outer surface than to the inner surface.

8. The cutting tool according to claim 5 , wherein the end of the adjustment member is flat.

9. The adjustment member is located behind the slit, The cutting tool according to claim 5 , wherein the central axis of the adjustment member extends perpendicular to the slit.

10. the main body portion has a first coolant hole extending from the rear end toward the front end, The cutting portion is a cartridge attached to the pocket; a first insert attached to the cartridge and having the cutting edge; the cartridge has a second coolant hole extending from the rear end toward the front end and connected to the first coolant hole, The cutting tool according to claim 1 , wherein the second coolant hole opens toward an upper surface of the first insert.

11. The cutting tool according to claim 10 , wherein the second coolant hole is located forward of the slit in the rotational direction in a cross section perpendicular to the cutting edge.

12. A step of rotating the cutting tool according to any one of claims 1 to 11; contacting the cutting tool with a workpiece; and removing the cutting tool from the workpiece.

Images