Cutting tool and method for manufacturing machined product

Abstract

A cutting tool based on one embodiment of the present disclosure has a body section that has a pocket and extends from a distal end toward a rear end along a rotating shaft, a cutting part positioned in the pocket, and an elastic body that is positioned between the body section and the cutting part and that applies a biasing force in a direction toward the rear end to the cutting part. The pocket has a first seat surface facing forward in the direction of rotation of the rotating shaft. The cutting part has a rearward surface that is positioned rearward in the direction of rotation of the rotating shaft and that contacts the first seat surface. The elastic body contacts the first seat surface and the rearward surface. The rearward surface is capable of sliding along the rear end.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to Japanese Patent Application No. 2021-142555, filed on September 1, 2021, 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 turning tool (milling tool). The turning tool can be used for turning processes such as face milling and end milling. [Background technology]

[0003] Known cutting tools include the milling tools described in International Publication No. 2013 / 029072 (Patent Document 1), International Publication No. 2004 / 080633 (Patent Document 2), and JP Patent Publication No. 2005-111651 (Patent Document 3). In general, when face milling is performed using a milling tool, there is a risk of an iris pattern being generated 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 toward the front in the feed direction. This avoids the risk of iris pattern 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 pattern on the machined surface of the workpiece caused by the relief portion.

[0005] However, as described in Patent Documents 1 and 2, tilting the rotation axis toward the front of the feed direction is possible in a machine in which the machining direction is limited to one axis, such as a general-purpose milling cutter, but is difficult to introduce into a general machining center or the like in which the machining direction is one or more axes. In other words, the milling tools described in Patent Documents 1 and 2 have poor versatility.

[0006] In addition, in the cutting tool described in Patent Document 3, the wiper blade located at the front in the feed direction and the wiper blade located at the rear in the feed direction are located at the same position in the direction 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 embodiment of the present disclosure includes a body portion extending from a tip end to a rear end along a rotation shaft and having a pocket located on the tip end side, a cutting portion located in the pocket and having a cutting edge located on the tip end side, and an elastic body located between the body portion and the cutting portion and applying a biasing force to the cutting portion in a direction toward the rear end. The pocket has a first seating surface facing forward in the rotation direction of the rotation shaft. The cutting portion is located rearward in the rotation direction of the rotation shaft and has a rear surface in contact with the first seating surface. The elastic body abuts against the first seating surface and the rear surface. The rear surface is slidable toward the rear end. [Brief description of the drawings]

[0008] [Figure 1] 1 is a perspective view showing a cutting tool according to a first embodiment. [Diagram 2] 2 is a plan view of the cutting tool shown in FIG. 1, as viewed from a direction A1. [Diagram 3] 2 is a plan view of the cutting tool shown in FIG. 1 as viewed from a direction A2. [Figure 4] 2 is a perspective view showing a main body (first cartridge), a first cutting part, a fixture, etc., of the cutting tool shown in FIG. 1. [Diagram 5] 5 is a plan view of the area shown in FIG. 4 as viewed from the A3 direction. [Figure 6] 5 is a plan view of the area shown in FIG. 4 as viewed from the A4 direction. [Figure 7] 5 is a plan view of the area shown in FIG. 4 as viewed from the A5 direction. [Figure 8] FIG. 5 is a perspective view showing a main body part in FIG. [Figure 9] FIG. 5 is a perspective view showing a first cutting portion in FIG. 4. [Figure 10] 7 is a cross-sectional view taken along line XX in FIG. 6, illustrating a state in which the portion shown in FIG. 4 is cut. [Figure 11] 11 is a cross-sectional view showing a state of the portion shown in FIG. 10 when not being cut. [Figure 12] 9 is a perspective view of a first modified example of the main body shown in FIG. 8. FIG. [Figure 13] 10 is a perspective view of a first modified example of the first cutting portion shown in FIG. 9. [Figure 14] 9 is a perspective view of a second modified example of the main body shown in FIG. 8. FIG. [Figure 15] 10 is a perspective view of a second modified example of the first cutting portion shown in FIG. 9. [Figure 16] 11 is a cross-sectional view showing a main body, a first cutting portion, a fastener, etc. of a cutting tool according to a second embodiment, and corresponds to FIG. 10. FIG. [Figure 17] FIG. 11 is a perspective view showing a cutting tool according to a third embodiment. [Figure 18] FIG. 18 is a plan view of the cutting tool shown in FIG. 17 as viewed from the tip side. [Figure 19] 18 is a perspective view showing a first cutting portion, a fixing device, a bearing member, etc., of the cutting tool shown in FIG. 17. [Figure 20] 20 is a plan view of the portion shown in FIG. 19, and corresponds to FIG. 6. [Figure 21] FIG. 19 is an enlarged view of the cross section XXI-XXI shown in FIG. [Figure 22] 20 is a plan view of the portion shown in FIG. 19, and corresponds to FIG. 5. [Figure 23] FIG. 23 is a schematic diagram showing the positional relationship during cutting and non-cutting in the area shown in FIG. 22. [Figure 24] FIG. 11 is a perspective view showing a cutting tool according to a fourth embodiment. [Diagram 25] FIG. 25 is a plan view of the cutting tool shown in FIG. 24. [Figure 26] FIG. 25 is a plan view of the cutting tool shown in FIG. 24 as viewed from the tip side. [Figure 27]FIG. 26 is an enlarged view of the cross section XXVII-XXVII shown in FIG. 25. [Figure 28] 25 is a perspective view showing a first cutting portion, a fixing device, and a bearing member of the cutting tool shown in FIG. 24. [Figure 29] 29 is a plan view of the portion shown in FIG. 28 and corresponds to FIG. 5. FIG. [Diagram 30] FIG. 2 is a schematic explanatory diagram showing one step of a method for producing a machined product according to one embodiment. [Diagram 31] FIG. 2 is a schematic explanatory diagram showing one step of a method for producing a machined product according to one embodiment. [Diagram 32] FIG. 2 is a schematic explanatory diagram showing one step of a method for producing a machined product according to one embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, the cutting tools of the first to fourth embodiments of the present disclosure will be described in detail with reference to the drawings. However, for the convenience of explanation, each of the drawings referred to below shows only the main members necessary for explaining each embodiment in a simplified manner. Therefore, the cutting tool of the present disclosure may include any component member not shown in each of the drawings referred to. In addition, the dimensions of the members in each drawing do not faithfully represent the dimensions of the actual components and the dimensional ratios of each member. In addition, in the cutting process, the cutting time indicates a state in which the cutting tool and the workpiece are in contact, and the non-cutting time indicates a state in which the cutting tool and the workpiece are not in contact. In addition, in the drawings, the state of the cutting tool when not cutting is shown unless otherwise specified.

[0010] The cutting tool 1A according to the first embodiment has a rotation axis O1, as shown in a non-limiting example in Fig. 1, and is a so-called rotating tool. Examples of rotating tools include milling tools and end mills. The rotating tool shown in Fig. 1, as a non-limiting example, is a milling tool. Note that the rotation axis O1 is an axis about which the cutting tool 1A rotates, and is not a tangible object that the cutting tool 1A (main body portion 3) has.

[0011] The cutting tool 1A includes a main body 3, a cutting part 5, and an elastic body 7, as a non-limiting example shown in FIG. 1 and the like. The main body 3 extends from a tip 3A to a rear end 3B along a rotation axis O1. The main body 3 has a pocket 9 located on the tip 3A side. The cutting part 5 has a cutting edge 11 located in the pocket 9 and also located on the tip 3A side (see FIG. 4 and the like). The elastic body 7 is located between the main body 3 and the cutting part 5 (see FIG. 10 and the like).

[0012] The main body 3 is a base portion of the cutting tool 1A. The pocket 9 may be open on the outer peripheral surface of the main body 3 and on the end surface on the side of the tip 3A. The pocket 9 may be only one, or may be multiple as in a non-limiting example shown in FIG. 3. FIG. 3 is a view of the cutting tool 1A shown in FIG. 1 as viewed from the A2 direction (as viewed from the tip 3A side). When the main body 3 has multiple pockets 9, one of the multiple pockets 9 is defined as the first pocket 9A. The cutting part 5 is not limited to only one as shown in FIG. 1, and may be multiple. When the cutting tool 1A has multiple pockets 9, the cutting part 5 located in the first pocket 9A is defined as the first cutting part 5A.

[0013] An insert may be attached to each pocket. As a non-limiting example shown in FIG. 1, cutting inserts 12 may be attached as inserts to a plurality of pockets other than the first pocket 9A. There may be only one elastic body 7, or there may be multiple elastic bodies 7. When the cutting tool 1A has multiple elastic bodies 7, the elastic body 7 located between the main body portion 3 and the first cutting portion 5A is defined as the first elastic body 7A.

[0014] The rotation direction O2 is not limited to the clockwise direction shown in Fig. 1. For example, when the cutting tool 1A has a configuration inverted around the rotation axis O1 with respect to the configuration shown in Fig. 1, the rotation direction O2 may be counterclockwise.

[0015] In a non-limiting example shown in FIG. 1, the cutting tool 1A of the first embodiment has a cylindrical shape extending from the front end 3A to the rear end 3B along the rotation axis O1. For convenience of explanation, the parts of the main body 3 located on the front 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 1A has a first pocket 9A and the like, the cutting tool 1A is not strictly cylindrical. The length of the main body 3 in the direction along the rotation axis O1 is, for example, 50 mm to 100 mm. The outer diameter of the main body 3 in the direction perpendicular to the rotation axis O1 is, for example, 100 mm to 300 mm.

[0016] The main body 3 is capable of rotating about a rotation axis O1. There is no particular limitation on the shape of the main body 3, and it may be, for example, substantially cylindrical or substantially conical, and may have irregularities.

[0017] The main body 3 may be composed of one member or may be composed of multiple members. For example, as in a non-limiting example shown in Fig. 1, the main body 3 may have a base 13 and a first cartridge 15. Note that the main body 3 may have members other than the base 13 and the first cartridge 15.

[0018] The first cartridge 15 is a member attached to the base 13. The first cartridge 15 may be used to form the first pocket 9A in the main body 3. In a non-limiting example shown in Fig. 2, the first pocket 9A is adjacent to the first cartridge 15 in front of the rotation direction O2 of the rotation axis O1. Note that Fig. 2 is a view of the cutting tool 1A shown in Fig. 1 as viewed from the A1 direction (side view).

[0019] The first cartridge 15 may have a first hole 17 that opens as shown in a non-limiting example in Fig. 5. Fig. 5 is a view (side view) of the part in Fig. 4 as viewed from the A3 direction. The first hole 17 may be used as an insertion hole for a first fastener 19 when mounting the first cartridge 15 to the base body 13. Examples of the first fastener 19 include a screw and a clamp.

[0020] The first pocket 9A has a first seating surface 21 facing forward in the rotational direction O2 of the rotation axis O1. In other words, the main body 3 has the first seating surface 21. In a non-limiting example shown in FIG. 4, the first cartridge 15 has the first seating surface 21.

[0021] The first cutting part 5A located in the first pocket 9A has a cutting edge 11 located on the side of the first end 3A. A machined product can be manufactured by cutting a workpiece with this cutting edge 11. The first cutting part 5A may be composed of one member or may be composed of multiple members. In a non-limiting example shown in FIG. 4, the first cutting part 5A has a first insert 23 and a second cartridge 25.

[0022] In a non-limiting example shown in FIG. 4, the first insert 23 has a cutting edge 11. The cutting edge 11 is located in front of the first insert 23 in the rotation direction O2 and on the first end 3A side. It is not necessary that the cutting edge 11 is located only in this portion. For example, when the cutting edge 11 located in front of the first insert 23 in the rotation direction O2 and on the first end 3A side is defined as the first cutting edge 27, the first insert 23 may further have a second cutting edge 29 located in front of the first insert 23 in the rotation direction O2 and on the outer periphery side. The first cutting edge 27 and the second cutting edge 29 are not limited to a straight shape as shown in FIG. 6, and may be curved. It is noted that FIG. 6 is a view (front view) of the portion in FIG. 4 as viewed from the A4 direction.

[0023] The first insert 23 is located forward in the rotational direction O2 relative to the second cartridge 25. The first insert 23 may have a second hole 31 and be fixed to the second cartridge 25 using a second fastener 33 such as a screw, as in a non-limiting example shown in Fig. 7. Note that Fig. 7 is a view of the portion in Fig. 4 as viewed from the A5 direction (as viewed from the first end 3A side).

[0024] The length of the first cutting portion 5A in the direction along the rotation axis O1 is, for example, 30 mm to 50 mm.The length of the first cutting portion 5A in the direction perpendicular to the rotation axis O1 is, for example, 15 mm to 35 mm.

[0025] The first cutting portion 5A may have a front surface 35. The front surface 35 is a surface of the first cutting portion 5A that is located in front of the rotation direction O2. There is no particular limitation on the shape of the front surface 35, and it may be, for example, a flat or curved shape, or may have an uneven portion. The front surface 35 may have a first side 37, a second side 39, and a first corner 41. The first side 37 may be located on the side of the first end 3A. The second side 39 may be located on the outer periphery side away from the rotation axis O1. The first corner 41 may be a corner connected to the first side 37 and the second side 39.

[0026] The first cutting edge 27 may be located on the first side 37. As described above, since the first side 37 is located on the side of the first end 3A, the first cutting edge 27 located on the first side 37 can be located on the side of the first end 3A in the cutting portion 5. Furthermore, the second cutting edge 29 may be located on the second side 39. As described above, since the second side 39 is located on the side away from the rotation axis O1, the second cutting edge 29 located on the second side 39 can be located on the side away from the rotation axis O1 in the cutting portion 5.

[0027] The first cutting portion 5A may have a third cutting edge 43 located at the first corner 41. The third cutting edge 43 may be arranged continuously with the first cutting edge 27 or the second cutting edge 29. The third cutting edge 43 is not limited to a curved shape as shown in Fig. 6, and may have a straight line portion or may be an arc shape.

[0028] The first cutting portion 5A may have a rear surface 45. The rear surface 45 is a surface of the first cutting portion 5A that is located rearward in the rotation direction O2. There is no particular limitation on the shape of the rear surface 45, and it may be, for example, a flat or curved shape, or may have an uneven portion. The rear surface 45 of the first cutting portion 5A faces the first seat surface 21 of the first pocket 9A.

[0029] The first seating surface 21 may be in contact with the rear surface 45, as in a non-limiting example shown in Fig. 5 etc. In such a case, the sliding direction of the rear surface 45 is likely to be stable. Note that in this case, "in contact" does not mean that the first seating surface 21 and the rear surface 45 are in contact with each other entirely without any gaps. Specifically, there may be a gap of 0.05 mm to 0.01 mm between the first seating surface 21 and the rear surface 45.

[0030] The first elastic body 7A is located between the main body 3 and the first cutting portion 5A, as in a non-limiting example shown in FIG. 10. FIG. 10 is a diagram showing a state in which the part shown in FIG. 4 is cut along the XX line shown in FIG. 6 during cutting. The XX section is a section passing through the center of the second cartridge 25 and parallel to the rotation axis O1. The XX section may include the central axis N1 of the first elastic body 7A (see FIG. 11). Specifically, the first elastic body 7A is located between the first seating surface 21 of the first pocket 9A and the rear surface 45 of the first cutting portion 5A. At this time, the first elastic body 7A may abut against the first seating surface 21 and the rear surface 45. The first elastic body 7A can apply a biasing force toward the second end 3B to the first cutting portion 5A. The rear surface 45 can slide toward the second end 3B. In other words, since the rear surface 45 is a part of the first cutting portion 5A, the first cutting portion 5A is able to slide.

[0031] In a non-limiting example shown in FIG. 30, when cutting a workpiece, the cutting tool 1A advances in a predetermined direction (so-called feed direction Y1) while rotating around the rotation axis O1. The first cutting part 5A can contribute to the cutting when it is located forward in the feed direction Y1 relative to the rotation axis O1. On the other hand, when the first cutting part 5A is located rearward in the feed direction Y1 relative to the rotation axis O1, it is desired that it does not contribute to the cutting. This is because there is a risk that the machined surface will be scratched and a so-called iris pattern will be formed on the machined surface by contacting the workpiece when the first cutting part 5A is located rearward in the feed direction Y1 relative to the rotation axis O1.

[0032] 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 cutting portion 5 in a direction toward the workpiece, in other words, in a direction away from the second end 3B. Therefore, the first cutting portion 5A is drawn into the workpiece, and cutting tends to progress. At this time, that is, the position of the first cutting edge 27 during cutting is defined as the first cutting edge position S1 (see FIG. 10).

[0033] Here, the cutting tool 1A according to the first embodiment has a first elastic body 7A. Therefore, when the first cutting part 5A is located rearward in the feed direction Y1 with respect to the rotation axis O1, the first elastic body 7A can apply a biasing force toward the second end 3B to the first cutting part 5A. At this time, the rear surface 45 of the first cutting part 5A can slide toward the second end 3B. Therefore, compared with when the first cutting part 5A is located forward in the feed direction Y1 with respect to the rotation axis O1, when the first cutting part 5A is located rearward in the feed direction Y1 with respect to the rotation axis O1, the first cutting part 5A can slide toward the second end 3B. At this time, that is, the position of the first cutting edge 27 when not cutting is set as the second cutting edge position S2 (see FIG. 11). Note that FIG. 11 is a view corresponding to FIG. 10, and shows the state of the part shown in FIG. 4 when not cutting. The distance (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.

[0034] When the first cutting portion 5A is positioned rearward in the feed direction Y1 relative to the rotation axis O1, the first cutting portion 5A slides toward the second end 3B, making it less likely that the first cutting portion 5A will come into contact with the workpiece.

[0035] In other words, when the first cutting portion 5A is positioned forward in the feed direction Y1 relative to the rotation axis O1, the first cutting portion 5A comes into contact with the workpiece and can cut the workpiece by the first cutting portion 5A, whereas when the first cutting portion 5A is positioned backward in the feed direction Y1 relative to the rotation axis O1, the first cutting portion 5A slides in a direction away from the workpiece, and therefore the first cutting portion 5A is less likely to come into contact with the workpiece.

[0036] The above-mentioned action reduces 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 forward in the feed direction, so the cutting direction is not limited to one direction, and the travel distance of the tool can be reduced. Therefore, the above-mentioned action is highly versatile and contributes to shortening the processing time.

[0037] In the cutting tool 1A, the first insert 23 may be a so-called wiper insert. That is, the cutting insert 12 performs normal milling on the workpiece, while the first insert 23 may be a finishing insert for improving the surface accuracy of the machined surface of the workpiece. In this case, the first insert 23 may protrude toward the first end 3A compared to the cutting insert 12.

[0038] Elastic body 7 may be located in pocket 9 (first pocket 9A) in which first insert 23, which is an insert for a wiper, is attached, but may not be located in pocket 9 in which cutting insert 12, which is an insert for performing normal milling, is attached. In this case, cutting tool 1A can have the minimum number of elastic bodies 7 required, while reducing the risk of iris patterning. In other words, the complex structure for attaching elastic body 7 can be kept to a minimum, and the manufacturing cost of cutting tool 1A can be reduced while reducing the risk of iris patterning.

[0039] As described above, when the first elastic body 7A abuts against the first seating surface 21 and the rear surface 45, the first elastic body 7A tends to move the relative position of the first cutting portion 5A (having the rear surface 45) with respect to the main body portion 3 (having the first seating surface 21) toward the second end 3B.

[0040] The first elastic body 7A is a member (elastic member) that is more easily elastically deformed than the main body 3 and the first cutting portion 5A. The first elastic body 7A is not limited to being composed of a single elastic member, and may be a combination of multiple elastic members. The first elastic body 7A may also be configured to include a member other than the elastic member. Here, the member other than the elastic member included in the first elastic body 7A refers to a member that is joined to the elastic member and used integrally with the elastic member, and applies a biasing force to the target together with the elastic member. The target may be the first cutting portion 5A, etc. An example of a member other than the elastic member is a pin 47, as shown in FIG. 10 as a non-limiting example.

[0041] The elastic member is not limited to a specific material. For example, the elastic member may be various springs and members with a high Young's modulus. Specific examples of springs include leaf springs, disc springs, and helical springs. A high Young's modulus does not have to be equal to or higher than a specific value, but may be higher than, for example, the main body 3 and the first cutting portion 5A. The Young's modulus can be evaluated by, for example, a well-known nanoindentation method. In the cutting tool 1A of the first embodiment, a helical spring 48 is used.

[0042] Examples of materials with a high Young's modulus include resins and rubbers. Examples of resins include polycarbonate resins, polyethylene terephthalate resins, acrylic resins, polyvinyl chloride resins, silicone resins, and epoxy resins. Examples of rubbers include natural rubbers and synthetic rubbers.

[0043] The first elastic body 7A applies a biasing force to the first cutting portion 5A. Here, the biasing force may be a force acting when the elastically deformed elastic body 7 returns to its original state, or may be referred to as an elastic force. The biasing force may be not only a force applied directly to the first cutting portion 5A by the first elastic body 7A, but also a force applied indirectly to the first cutting portion 5A by the first elastic body 7A via another member. The first elastic body 7A may apply a biasing force so that the first cutting portion 5A has a fulcrum and the first cutting portion 5A rotates around the fulcrum, thereby sliding toward the second end 3B. The first elastic body 7A may apply a biasing force to the first cutting portion 5A in a direction other than the direction toward the second end 3B, for example, forward or backward in the rotation direction O2.

[0044] The rear surface 45, i.e., the first cutting part 5A, is slidable toward the second end 3B. Here, being slidable toward the second end 3B does not mean that it is slidable only in the direction of the second end 3B, but means that it has an element (vector) of sliding in the direction of the second end 3B. Therefore, for example, in the process of sliding, the first cutting part 5A may move toward or away from the rotation axis O1, or may move forward or backward in the rotation direction O2.

[0045] The first bearing surface 21 may be inclined forward in the rotation direction O2 as it approaches the second end 3B, as in a non-limiting example shown in FIG. 5. In other words, the first bearing surface 21 may be inclined backward in the rotation direction O2 as it approaches the first end 3A. In such a case, the cutting load received by the first bearing surface 21 is easily dispersed in the direction along the rotation axis O1. This makes it possible to suppress damage to the first cartridge 15, i.e., the main body 3, caused by the cutting load. In addition, when the first cutting portion 5A is positioned forward in the feed direction Y1 relative to the rotation axis O1 to cut the workpiece, the first cutting portion 5A slides in a direction approaching the workpiece, and the workpiece is easily cut appropriately. Therefore, when the first cutting portion 5A is positioned backward in the feed direction Y1 relative to the rotation axis O1, the first cutting portion 5A is less likely to come into contact with the workpiece.

[0046] The first bearing surface 21 is not limited to the shape of the example shown in Fig. 8, and may be flat or curved, and may have uneven portions. In addition, the inclination toward the front in the rotation direction O2 toward the second end 3B does not necessarily mean that the inclination continues strictly, and may include a portion parallel to the rotation axis O1.

[0047] As a non-limiting example shown in FIG. 8, the first seating surface 21 may have a first recess 49, and as a non-limiting example shown in FIG. 9, the rear surface 45 may have a second recess 51. As a non-limiting example shown in FIG. 10, the second recess 51 may face the first recess 49. The first elastic body 7A may be inserted into the first recess 49 and the second recess 51. Also, the first elastic body 7A may be in contact with the first recess 49 and the second recess 51. When the first elastic body 7A is inserted into the first recess 49 and the second recess 51, it is easy to bring the first seating surface 21 and the rear surface 45 into contact while positioning the first elastic body 7A between the main body 3 and the first cutting portion 5A. Also, when the first elastic body 7A is in contact with the first recess 49 and the second recess 51, the urging force can be efficiently transmitted to the first cutting portion 5A.

[0048] Note that "the second recess 51 faces the first recess 49" in the above means that at least a part of the opening 49A of the first recess 49 and at least a part of the opening 51A of the second recess 51 are continuous (see FIG. 11). Therefore, for example, the shape of the opening 49A of the first recess 49 and the shape of the opening 51A of the second recess 51 do not need to match, and the entirety of the opening 49A of the first recess 49 and the entirety of the opening 51A of the second recess 51 do not need to face each other.

[0049] There is no particular limitation on the shape of the first recess 49, nor on the width and depth of the first recess 49. The width of the first recess 49 may be constant or may vary.

[0050] The shape of the second recess 51 is not particularly limited, like the shape of the first recess 49. In addition, the width and depth of the second recess 51 are not particularly limited, like the width and depth of the first recess 49.

[0051] The first elastic body 7A may be fitted into and cross the first recess 49. For example, in FIG. 10, the pin 47 and the helical spring 48 are fitted into and cross the first recess 49, and can slide in a direction along the central axis N1 of the first elastic body 7A. Note that, as a non-limiting example shown in FIG. 11, the central axis N1 of the first elastic body 7A may coincide with the central axis N2 of the first recess 49. By fitting the first elastic body 7A into and crossing the first recess 49, the position of the first elastic body 7A is easily stabilized. Therefore, the first elastic body 7A is easily able to apply a biasing force to the rear surface 45. The first elastic body 7A may also be fitted into and cross the second recess 51. By fitting the first elastic body 7A into and crossing the second recess 51, the position of the first elastic body 7A is easily stabilized. Therefore, the first elastic body 7A is easily able to apply a biasing force to the rear surface 45.

[0052] As shown in a non-limiting example in FIG. 8, the first seating surface 21 may have a first groove 53. The first groove 53 may extend from the first end 3A side toward the second end 3B side. The shape of the first groove 53 is not limited to the example shown in FIG. 8, and may be a straight line or a curved line. The width and depth of the first groove 53 may not be constant. The number of first grooves 53 is not limited to one, and may be two or more.

[0053] As shown in a non-limiting example in FIG. 9, the rear surface 45 may have a first convex portion 55. The first convex portion 55 may be inserted into the first groove 53. By inserting the first convex portion 55 into the first groove 53, the sliding direction of the rear surface 45 is likely to be stable. The shape of the first convex portion 55 is not limited to the example shown in FIG. 9, and may be a straight line or a curved line. In addition, the width and height of the first convex portion 55 may not be constant. Note that FIG. 9 is a perspective view of the first cutting portion 5A seen from the rear surface 45 side.

[0054] Furthermore, the number of first convex portions 55 is not limited to one, and may be two or more. When the rear surface 45 has a plurality of first convex portions 55 corresponding to the first grooves 53 of the first seating surface 21, the sliding direction of the rear surface 45 becomes more stable. The first convex portion 55 may be in a linear shape corresponding to the first grooves 53, as in a non-limiting example shown in FIG. 9. When the first convex portion 55 has a linear shape, the sliding direction of the rear surface 45 becomes more stable.

[0055] As a non-limiting example shown in Fig. 8, the first groove 53 may have a first recess 49. Furthermore, as a non-limiting example shown in Fig. 9, the first convex portion 55 may have a second recess 51. In other words, the cutting tool 1A may have a first elastic body 7A between the first groove 53 and the first convex portion 55. When the cutting tool 1A has such a configuration, the widths of the first groove 53 and the first convex portion 55 become wider in the rotation direction of the rotation axis O1, and the sliding direction of the rear surface 45 becomes more stable.

[0056] As a non-limiting example shown in FIG. 12, the first groove 53 may approach the rotation axis O1 as it approaches the second end 3B. In other words, the first groove 53 may move away from the rotation axis O1 as it approaches the first end 3A. In this case, the cutting edge 11 moves toward the first end 3A during cutting and moves in a direction away from the rotation axis O1. Therefore, for example, when the second cutting edge 29 is included, the feed rate in milling can be increased. Note that "approaching the rotation axis O1 as it approaches the second end 3B" does not necessarily mean that the groove continues to approach the rotation axis O1 strictly, and may include a portion parallel to the rotation axis O1.

[0057] 13, the first convex portion 55 may approach the rotation axis O1 as it approaches the second end 3B. In other words, the first convex portion 55 may move away from the rotation axis O1 as it approaches the first end 3A. Note that "getting closer to the rotation axis O1 as it approaches the second end 3B" does not necessarily mean that the first convex portion 55 continues to get closer to the rotation axis O1 strictly speaking, and may include a portion that is parallel to the rotation axis O1.

[0058] The first recess 49 and the second recess 51 may be located closer to the rotation axis O1 than the first groove 53. In other words, the first elastic body 7A may be located closer to the rotation axis O1 than the first groove 53. That is, the distance between the rotation axis O1 and the first elastic body 7A may be smaller than the distance between the rotation axis O1 and the first groove 53. The cutting load received from the machined surface during cutting is larger in the portion of the first seating surface 21 farther from the rotation axis O1 than in the portion of the first seating surface 21 closer to the rotation axis O1. In the above case, the resistance force received by the first elastic body 7A from the machined surface during cutting is smaller, and the occurrence of damage to the first elastic body 7A can be suppressed.

[0059] As a non-limiting example shown in FIG. 15, the rear surface 45 may have a second groove 57. The second groove 57 may extend from the first end 3A side toward the second end 3B side. The shape of the second groove 57 is not particularly limited, and may be, for example, a straight or curved shape. In addition, the width and depth of the second groove 57 may not be constant. The number of second grooves 57 is not limited to one, and may be two or more.

[0060] As shown in a non-limiting example in FIG. 14, the first seating surface 21 may have a second convex portion 59. The second convex portion 59 may be inserted into the second groove 57. By inserting the second convex portion 59 into the second groove 57, the sliding direction of the rear surface 45 is likely to be stable. The shape of the second convex portion 59 is not particularly limited. The shape of the second convex portion 59 is not limited to the example shown in FIG. 14, and may be a straight line or a curved line. In addition, the width and height of the second convex portion 59 do not have to be constant.

[0061] Furthermore, the number of second convex portions 59 is not limited to one, and may be two or more. When the first seating surface 21 has a plurality of second convex portions 59 corresponding to the second grooves 57 of the rear surface 45, the sliding direction of the rear surface 45 becomes more stable. The second convex portion 59 may be in a linear shape corresponding to the second grooves 57, as in a non-limiting example shown in FIG. 14. In this way, when the second convex portion 59 has a linear shape, the sliding direction of the rear surface 45 becomes more stable.

[0062] As a non-limiting example shown in FIG. 15, the second groove 57 may approach the rotation axis O1 as it approaches the second end 3B. In other words, the second groove 57 may move away from the rotation axis O1 as it approaches the first end 3A. In such a case, the cutting edge 11 moves toward the first end 3A during cutting and moves in a direction away from the rotation axis O1. Therefore, for example, when the second cutting edge 29 is included, the feed rate in milling can be increased. Note that "approaching the rotation axis O1 as it approaches the second end 3B" does not necessarily mean that the groove continues to approach the rotation axis O1 strictly, and may include a portion parallel to the rotation axis O1.

[0063] 14, the second convex portion 59 may approach the rotation axis O1 as it approaches the second end 3B. In other words, the second convex portion 59 may move away from the rotation axis O1 as it approaches the first end 3A. Note that "getting closer to the rotation axis O1 as it approaches the second end 3B" does not necessarily mean that the second convex portion 59 continues to get closer to the rotation axis O1 strictly speaking, and may include a portion that is parallel to the rotation axis O1.

[0064] As a non-limiting example shown in FIG. 14 and FIG. 15, the first recess 49 and the second recess 51 may be located closer to the rotation axis O1 than the second groove 57. In other words, the first elastic body 7A may be located closer to the rotation axis O1 than the second groove 57. That is, the distance between the rotation axis O1 and the first elastic body 7A may be smaller than the distance between the rotation axis O1 and the second groove 57. The cutting load received from the machined surface during cutting is larger in the portion of the first seating surface 21 farther from the rotation axis O1 than in the portion of the first seating surface 21 closer to the rotation axis O1. In the above case, the resistance force received by the first elastic body 7A from the machined surface during cutting is smaller, and the occurrence of damage to the first elastic body 7A can be suppressed.

[0065] The first cutting portion 5A may have a first through hole 61. The first through hole 61 may open on the front surface 35 and the rear surface 45. The first cutting portion 5A may have a third fixing device 63 fixed to the main body portion 3, as in a non-limiting example shown in FIG. 6. The third fixing device 63 may be inserted into the first through hole 61. An example of the third fixing device 63 is a screw. The third fixing device 63 may be capable of maintaining the first cutting portion 5A in the pocket 9. Since the first cutting portion 5A is slidable, it is not necessary for the first cutting portion 5A to be completely fixed to the main body portion 3 by the third fixing device 63. By having the above-mentioned configuration of the first cutting portion 5A, the first cutting portion 5A can be stably held while being in a slidable state. The first cutting portion 5A may have a recessed portion that does not penetrate instead of the first through hole 61, and the first cutting portion 5A may be fixed to the main body portion 3 by fitting into the recessed portion.

[0066] The main body 3 may have a third recess 64. For example, in a non-limiting example shown in Fig. 8, the first cartridge 15 has the third recess 64. The third fixing tool 63 may be inserted into the third recess 64 through the first through-hole 61 of the first cutting part 5A.

[0067] The cutting tool 1B according to the second embodiment includes a main body 3, a first cutting part 5A, and a first elastic body 7A. In the cutting tool 1B according to the second embodiment, the description of the first embodiment is used for the parts having the same configuration as the cutting tool 1A according to the first embodiment, and detailed description thereof will be omitted. Fig. 16 is a view of the cutting tool 1B according to the second embodiment, corresponding to Fig. 10.

[0068] While the first elastic body 7A in the cutting tool 1A of the first embodiment is composed of a pin 47 and a helical spring 48, the first elastic body 7A in the cutting tool 1B of the second embodiment is composed of a material with a high Young's modulus.

[0069] The first elastic body 7A in the cutting tool 1B of the second embodiment is not limited to a specific shape, and may be, for example, a columnar shape as shown in a non-limiting example in Fig. 16. Note that the end surface of the columnar first elastic body 7A may be polygonal or circular.

[0070] The cutting tool 1C of the third embodiment includes a main body 3, a first cutting part 5A, and a first elastic body 7A, as shown in a non-limiting example in Figs. 17 to 23. In the cutting tool 1C of the third embodiment, the description of the first embodiment is used for the parts having the same configuration as the cutting tool 1A of the first embodiment, and detailed description is omitted. Note that Fig. 21 is an enlarged cross-sectional view of the cutting tool 1C according to the third embodiment cut along line XXI-XXI in Fig. 18. The XXI-XXI cross section is a cross section passing through the center of the second cartridge 25 and parallel to the rotation axis O1.

[0071] The cutting tool 1D of the fourth embodiment includes a main body 3, a first cutting part 5A, and a first elastic body 7A, as shown in a non-limiting example in Figs. 24 to 29. In the cutting tool 1D of the fourth embodiment, the description of the first embodiment is used for the parts having the same configuration as the cutting tool 1A of the first embodiment, and detailed description thereof will be omitted. Fig. 27 is an enlarged cross-sectional view of the cutting tool 1D according to the fourth embodiment cut along the line XXVII-XXVII in Fig. 25. The XXVII-XXVII cross section is a cross section passing through the center of the first elastic body 7A and perpendicular to the rotation axis O1.

[0072] In the cutting tool 1A according to the first embodiment, one of the first seating surface 21 and the rear surface 45 has a groove (the first groove 53 or the second groove 57), so that the first cutting part 5A can slide linearly. On the other hand, the cutting tool 1C according to the third embodiment and the cutting tool 1D according to the fourth embodiment can rotate about the central axis (rotation axis O3) of the third fixture 63, as in the non-limiting example shown in Figs. 19 and 28. That is, the first cutting part 5A can slide around the third fixture 63.

[0073] The cutting tool 1C and the cutting tool 1D may further include a bearing member 65 between the main body portion 3 and the first cutting portion 5A as a non-limiting example shown in Figures 20 and 28. When the cutting tool 1C and the cutting tool 1D include such a member, the first cutting portion 5A can slide smoothly around the third fixture 63.

[0074] The bearing member 65 may be located between the first through hole 61 and the third fixture 63. The cutting tool 1C and the cutting tool 1D have such a configuration, so that the first cutting part 5A can slide smoothly around the third fixture 63. As shown in a non-limiting example in FIG. 19, in the cutting tool 1C, the first through hole 61 may open on a surface of the first cutting part 5A closer to the rotation axis O1 and a surface away from the rotation axis O1. As shown in a non-limiting example in FIG. 28, in the cutting tool 1D, the first through hole 61 may open on a surface of the first cutting part 5A on the first end 3A side and a surface on the second end 3B side.

[0075] In the cutting tool 1C and the cutting tool 1D, the first cutting part 5A may rotate in a rotation direction O4 of the rotation axis O3 during cutting, and the first cutting edge 27 may move to a first cutting edge position S1. On the other hand, when not cutting, the first cutting part 5A may rotate in a rotation direction O5 of the rotation axis O3, and the first cutting edge 27 may move to a second cutting edge position S2. In the direction along the rotation axis O1, the second cutting edge position S2 may be located closer to the second end 3B than the first cutting edge position S1. The distance (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. As shown in a non-limiting example in FIG. 23 and FIG. 27, the rotation direction O4 and the rotation direction O5 are opposite to each other in the rotation direction of the rotation axis O3. In addition, in FIG. 23, the solid line indicates the cutting tool 1C during cutting, and the dotted line indicates the cutting tool 1C during non-cutting.

[0076] In the cutting tool 1A according to the first embodiment, the first cutting part 5A slides linearly in a direction along the rotation axis O1, so that the central axis N1 of the first elastic body 7A may extend in a direction along the rotation axis O1, as in a non-limiting example shown in FIG. 11. On the other hand, in the cutting tool 1D according to the third embodiment and the cutting tool 1D according to the fourth embodiment, the first cutting part 5A slides around the third fixture 63, so that the central axis N1 of the first elastic body 7A may extend in a direction perpendicular to the line connecting the rotation axis O3 and the first elastic body 7A (the direction of the tangent line T1) in a cross section perpendicular to the rotation axis O3. In this case, as in a non-limiting example shown in FIG. 21, the intersection point P of the line connecting the rotation axis O3 and the first elastic body 7A and the tangent line T1 may be on the first elastic body 7A. By having such a configuration in the cutting tool 1C and the cutting tool 1D, the first elastic body 7A can efficiently apply a biasing force to the first cutting part 5A. As a non-limiting example shown in FIG. 21, the central axis N1 of the first elastic body 7A may coincide with the tangent line T1.

[0077] 22, in a side view of the cutting tool 1C, the first cutting edge 27 may be located further forward than the rotation axis O3 in the rotation direction O2 of the rotation axis O1. With the cutting tool 1C having such a configuration, the first cutting edge 27 is more likely to move toward the first end 3A during cutting. That is, in the direction along the rotation axis O1, the first cutting edge position S1 is more likely to be located toward the first end 3A than the second cutting edge position S2.

[0078] In the fourth embodiment, as in a non-limiting example shown in Fig. 29, when the cutting tool 1D is viewed from the side, the first cutting edge 27 may be located forward of the rotation axis O3 in the rotation direction O2 of the rotation axis O1. With the cutting tool 1D having such a configuration, the cutting edge 11 moves in the rotation direction O5 during cutting. That is, the cutting edge 11 moves toward the first end 3A and moves in a direction away from the rotation axis O1. Therefore, for example, when the cutting tool 1D has the second cutting edge 29, the feed rate in milling can be increased.

[0079] In the fourth embodiment, the third fixture 63 may be inclined so as to approach the rear in the rotation direction O2 of the rotation axis O1 as it approaches the second end 3B in the direction along the rotation axis O1. In other words, the central axis (rotation axis O3) of the third fixture 63 may be inclined so as to approach the rear in the rotation direction O2 of the rotation axis O1 as it approaches the second end 3B in the direction along the rotation axis O1. The first through hole 61 and the bearing member 65 may also be inclined so as to approach the rear in the rotation direction O2 of the rotation axis O1 as it approaches the second end 3B in the direction along the rotation axis O1. When the cutting tool 1D has such a configuration, the first cutting edge 27 is more likely to move toward the first end 3A during cutting.

[0080] Examples of the material of the cutting insert 12 and the first insert 23 include cemented carbide and cermet. Examples of the composition of the cemented carbide include WC-Co, WC-TiC-Co, and WC-TiC-TaC-Co. WC-Co is produced by adding cobalt (Co) powder to tungsten carbide (WC) and sintering the mixture. WC-TiC-Co is produced by adding titanium carbide (TiC) to WC-Co. WC-TiC-TaC-Co is produced by adding tantalum carbide (TaC) to WC-TiC-Co.

[0081] Cermets are sintered composite materials in which a ceramic component is combined with a metal. Specifically, cermets include those whose main component is a titanium compound such as titanium carbide (TiC) or titanium nitride (TiN).

[0082] The surfaces of the cutting insert 12 and the first insert 23 may be coated with a coating by using a chemical vapor deposition (CVD) method or a physical vapor deposition (PVD) method. The coating composition may include titanium carbide (TiC), titanium nitride (TiN), titanium carbonitride (TiCN), alumina (Al2O3), etc.

[0083] The material of the substrate 13 may be steel, cast iron, aluminum alloy, etc. From the viewpoint of increasing toughness, the material of the substrate 13 may be steel.

[0084] The cutting tools 1A to 1D of the present disclosure include a main body 3, a cutting part 5, and a biasing means. The biasing means is located between the main body 3 and the first cutting part 5A, and is an element capable of applying a biasing force to the first cutting part 5A in a direction toward the second end 3B. The biasing means may be located between the first seating surface 21 and the rear surface 45. Specific examples of the biasing means include the first elastic body 7A described above. The biasing means is not limited to these configurations, and may utilize, for example, air pressure, hydraulic pressure, magnetic force, or the like.

[0085] In the cutting tools 1A to 1D of the present disclosure, the first cutting part 5A can slide toward the second end 3B by the biasing force applied by the biasing means, i.e., the first elastic body 7A. Therefore, compared with when the first cutting part 5A is positioned forward in the feed direction Y1 relative to the rotation shaft, when the first cutting part 5A is positioned rearward in the feed direction Y1 relative to the rotation shaft, the first cutting part 5A can slide toward the second end 3B. In other words, the biasing force is applied from the biasing means to the first cutting part 5A so that the position of the cutting edge 11 when not cutting is closer to the second end 3B than the position of the cutting edge 11 when cutting.

[0086] By applying a biasing force from the biasing means to the first cutting part 5A in this way, when the first cutting part 5A is located forward in the feed direction Y1 relative to the rotation axis, the workpiece can be cut by the first cutting part 5A, but when the first cutting part 5A is located rearward in the feed direction Y1 relative to the rotation axis, the workpiece is less likely to be cut by the first cutting part 5A. This reduces the risk of iris patterns.

[0087] <Method of manufacturing machined products> Next, a method for manufacturing a machined product according to a non-limiting embodiment of the present disclosure will be described in detail using the cutting tool 1A according to the above-mentioned non-limiting first embodiment as an example. Hereinafter, the description will be given with reference to Figs. 30 to 32. Note that Figs. 30 to 32 illustrate the steps of cutting a workpiece 102 as a non-limiting example of a method for manufacturing a machined product 101. Also, to facilitate visual understanding, the machined parts are hatched in Figs. 31 and 32.

[0088] A method for producing the machined product 101 according to a non-limiting embodiment of the present disclosure may include the following steps (1) to (3).

[0089] (1) The cutting tool 1A may be rotated about the rotation axis O1 in a rotation direction O2 and brought closer to the workpiece 102 in a feed direction Y1 (see FIG. 30).

[0090] This step can be performed, for example, by fixing the workpiece 102 on a table of a machine tool to which the cutting tool 1A is attached, and bringing the cutting tool 1A closer to the workpiece 102 while rotating it. Note that in this step, it is sufficient that the workpiece 102 and the cutting tool 1A are relatively close to each other, and the workpiece 102 may be brought closer to the cutting tool 1A.

[0091] (2) The cutting tool 1A may be brought even closer to the workpiece 102, so that the rotating cutting tool 1A comes into contact with a desired position on the surface of the workpiece 102, thereby cutting the workpiece 102 (see FIG. 31).

[0092] In this step, the cutting blade 11 may be brought into contact with a desired position on the surface of the workpiece 102 .

[0093] (3) The cutting tool 1A may be moved away from the workpiece 102 in the Y2 direction (see FIG. 32).

[0094] In this step, similarly to the above-mentioned step (1), the cutting tool 1A may be relatively separated from the workpiece 102, for example, the workpiece 102 may be separated from the cutting tool 1A. Note that, in addition to the milling process such as the non-limiting example shown in Fig. 32, examples of the cutting process may include plunge machining, copy machining, and oblique sinking machining.

[0095] By going through the above steps, it is possible to achieve excellent processability.

[0096] In addition, when performing cutting processing of the workpiece 102 as described above multiple times, for example, when performing multiple cutting processes on one workpiece 102, the process of contacting the cutting tool 1A with different locations on the workpiece 102 while keeping the cutting tool 1A rotating may be repeated.

[0097] Examples of the material of the workpiece 102 include carbon steel, alloy steel, stainless steel, cast iron, and non-ferrous metals. [Explanation of symbols]

[0098] 1A~1D...Cutting tools O1, O3...Rotation axis O2, O4, O5...Rotation direction 3. Main body 3A...Tip (1st end) 3B...Rear end (2nd end) 5...Cutting part 5A...1st cutting section 7. Elastic body 7A First elastic body 9. Pocket 9A: First pocket 11...Cutting edge 12. Cutting insert 13...Base 15...First Cartridge 17...1st hole 19...1st fixture 21. First seat 23...First insert 25...2nd Cartridge 27...First cutting edge 29...Second cutting edge 31...Second hole 33...Second fixture 35...front surface 37...First side 39...Second side 41...First corner 43...Third cutting edge 45...rear surface N1, N2...center axis Y1: Feed direction S1: First cutting edge position S2: Second cutting edge position 47···pin 48....Coil spring 49...First recess 49A...Opening part 51...Second recess 51A...Opening part 53...1st groove 55···First protrusion 57...2nd groove 59...Second protrusion 61...First through hole 63...Third fixture 64...3rd recess 65 Bearing parts T1...tangent P...intersection 101...Cutting workpiece 102...Work material

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 and having a cutting edge located on the side of the tip; an elastic body that is located between the main body portion and the cutting portion and applies a biasing force to the cutting portion in a direction toward the rear end, The pocket has a first seating surface facing forward in a rotation direction of the rotation shaft, the cutting portion is located rearward in a rotation direction of the rotating shaft and has a rear surface in contact with the first seating surface, The elastic body abuts against the first seat surface and the rear surface, The rear surface is slidable toward the rear end.

2. The cutting tool according to claim 1 , wherein the first bearing surface is inclined forward in the rotation direction as it approaches the rear end.

3. the first seating surface has a first recess; the rear surface has a second recess facing the first recess; The cutting tool according to claim 1 , wherein the elastic body is in contact with the first recess and the second recess.

4. The first seating surface has a first groove extending from the front end side toward the rear end side, The cutting tool according to claim 1 or 2, wherein the rear surface has a first protrusion inserted into the first groove.

5. The cutting tool according to claim 4 , wherein the first groove approaches the rotation axis as it approaches the rear end.

6. The cutting tool according to claim 4 , wherein the elastic body is located closer to the rotation shaft than the first groove.

7. the rear surface has a second groove extending from the front end side toward the rear end side, The cutting tool according to claim 1 , wherein the first seating surface has a second protrusion inserted into the second groove.

8. The cutting tool according to claim 7 , wherein the second groove approaches the rotation axis as it approaches the rear end.

9. The cutting portion is a front surface located forward in the rotation direction; a through hole opening at the front surface and the rear surface; The cutting tool according to claim 1 , further comprising: a fastener that is inserted into the through hole and fixed to the main body portion.

10. 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 and having a cutting edge located on the side of the tip; a biasing means located between the body portion and the cutting portion, A cutting tool in which a biasing force is applied to the cutting portion from the biasing means so that the position of the cutting blade when not in contact with a workpiece is closer to the rear end than the position of the cutting blade when in contact with the workpiece.

11. Rotating the cutting tool according to claim 1 or 10; contacting the cutting tool with a workpiece; and removing the cutting tool from the workpiece.

Images