JP7645394B2 - Cutting tool and method for manufacturing machined product - Google Patents

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to Japanese Patent Application No. 2021-168242, filed on October 13, 2021, the entire disclosure of which is incorporated herein by reference.

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.

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 2005-111651 A (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 of the feed direction.

In the cutting tools described in Patent Documents 1 and 2, the rotation axis of the cutting tool is inclined toward the front in the feed direction. This avoids the risk of iris patterns appearing on the machined surface of the workpiece. In the cutting tool described in Patent Document 3, a relief portion is provided to allow clearance for the wiper blade in the direction along the rotation axis. This avoids the risk of iris patterns appearing on the machined surface of the workpiece due to the relief portion.

However, as described in Patent Documents 1 and 2, tilting the rotation axis toward the front of the feed direction is possible in machines such as general-purpose milling cutters in which the machining direction is limited to one axis, but is difficult to introduce into general machining centers and 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 lack versatility.

In addition, in the milling tool described in Patent Document 3, the wiper blade located at the front of the feed direction and the wiper blade located at the rear of the feed direction are in 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.

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, a cutting portion located in the pocket and having a cutting edge located on the tip 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 axis and a second seating surface facing the tip. The cutting portion has a rear surface located rearward in the rotation direction of the rotation axis and in contact with the first seating surface, and a rear side surface located on the rear end side and facing the second seating surface. The elastic body abuts against the second seating surface and the rear side surface, and the rear surface is slidable toward the rear end.

1 is a perspective view showing a cutting tool according to a first embodiment. FIG. 2 is a plan view of the cutting tool shown in FIG. 1 as viewed from an A1 direction. 2 is a plan view of the cutting tool shown in FIG. 1 as viewed from a direction A2. 2 is a perspective view showing a main body (first cartridge), a first cutting part, a fixture, and the like in the cutting tool shown in FIG. 1 . FIG. 5 is a plan view of the member shown in FIG. 4 as viewed from the A3 direction. FIG. 5 is a plan view of the member shown in FIG. 4 as viewed from the A4 direction. 5 is a plan view of the member shown in FIG. 4 as viewed from the A5 direction. FIG. 5 is a perspective view showing a main body portion in FIG. 4 . FIG. 5 is a perspective view showing a first cutting portion in FIG. 4 . 7 is a cross-sectional view taken along the line XX shown in FIG. 6. FIG. 11 is a cross-sectional view showing a state of the member shown in FIG. 10 when not being cut. FIG. 9 is a perspective view of a first modified example of the main body shown in FIG. 8 . FIG. 10 is a perspective view of a first modified example of the first cutting portion shown in FIG. 9 . FIG. 9 is a perspective view of a second modified example of the main body shown in FIG. 8 . FIG. 10 is a perspective view of a second modified example of the first cutting portion shown in FIG. 9 . 11 is a cross-sectional view of a main body, a first cutting portion, a fastener, etc., of a cutting tool according to a second embodiment, the cross-sectional view corresponding to FIG. 10 . FIG. FIG. 11 is a perspective view showing a cutting tool according to a third embodiment. FIG. 18 is a plan view of the cutting tool shown in FIG. 17, and corresponds to FIG. 2; FIG. 18 is a plan view of the cutting tool shown in FIG. 17 as viewed from the tip side. 18 is a perspective view showing a first cutting portion, a fixing device, a bearing member, and the like in the cutting tool shown in FIG. 17. 21 is a plan view of the member shown in FIG. 20 and corresponds to FIG. 5 . 21 is a plan view of the member shown in FIG. 20 and corresponds to FIG. 6 . 21 is a plan view of the member shown in FIG. 20 and corresponds to FIG. 7. FIG. 23 is an enlarged view of the cross section XXIV-XXIV shown in FIG. 22. FIG. 25 is a cross-sectional view showing the member shown in FIG. 24 in a non-cutting state. FIG. 2 is a schematic explanatory diagram showing one step of a method for producing a machined product according to one embodiment. FIG. 2 is a schematic explanatory diagram showing one step of a method for producing a machined product according to one embodiment. FIG. 2 is a schematic explanatory diagram showing one step of a method for producing a machined product according to one embodiment.

The cutting tools of the first to third non-limiting embodiments 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 only the main components necessary for explaining each embodiment in a simplified form. Therefore, the cutting tool of the present disclosure may include any components not shown in the drawings referred to. Furthermore, the dimensions of the components in each drawing do not faithfully represent the dimensions of the actual components and the dimensional ratios of each component. In addition, during the cutting process, the cutting time refers to a state in which the cutting tool and the workpiece are in contact, and the non-cutting time refers to a state in which the cutting tool and the workpiece are not in contact. Furthermore, unless otherwise specified, each drawing shows the state of the cutting tool when not cutting.

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 non-limiting example rotating tool shown in FIG. 1 is a milling tool. Note that the rotation axis O1 is the axis about which the cutting tool 1A rotates, and is not a tangible object that the cutting tool 1A (main body portion 3) has.

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

The main body 3 is the base of the cutting tool 1A. The pocket 9 may open on the outer peripheral surface of the main body 3 and on the end surface on the side of the tip 3A. There may be only one pocket 9, or there may be multiple pockets 9 as shown in a non-limiting example 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 the first pocket 9A. The number of cutting parts 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 the first cutting part 5A.

An insert may be attached to each pocket. As a non-limiting example shown in FIG. 1, a cutting insert 12 may be attached as an insert to multiple pockets other than the first pocket 9A. The cutting insert 12 has a cutting blade 12a. A machined product can be manufactured by cutting the workpiece with this cutting blade 12a. The number of elastic bodies 7 may be only one or multiple. 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 referred to as the first elastic body 7A.

The rotation direction O2 is not limited to the direction shown in Fig. 1. For example, if 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 the opposite direction.

In a non-limiting example shown in FIG. 1, the cutting tool 1A of the first embodiment has a cylindrical shape extending from the tip 3A to the rear end 3B along the rotation axis O1. For ease of explanation, the parts of the main body 3 located on the tip 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, etc., 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.

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 be, for example, approximately disc-shaped or approximately conical, or may have irregularities.

The main body 3 may be composed of multiple members. For example, as shown in a non-limiting example in FIG. 1, the main body 3 has 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, or may be composed of a single member.

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 Figure 2, the first pocket 9A is adjacent to the first cartridge 15 and forward of the rotation direction O2 of the rotation axis O1. Note that Figure 2 is a view (side view) of the cutting tool 1A shown in Figure 1 as viewed from the A1 direction.

The first cartridge 15 has a first hole 17 that opens as shown in a non-limiting example in Figure 5. Note that Figure 5 is a view (side view) of the member in Figure 4 as seen from the A3 direction. The first hole 17 is used as an insertion hole for a first fastener 19 when attaching the first cartridge 15 to the base 13. Examples of the first fastener 19 include a screw and a clamp.

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 Figure 4, the first cartridge 15 has the first seating surface 21. The shape of the first seating surface 21 is not particularly limited, and may be a flat or curved shape, or may have uneven portions.

The first pocket 9A has a second seating surface 22 facing the first end 3A. In other words, the main body 3 has the second seating surface 22. In a non-limiting example shown in Figure 4, the first cartridge 15 has the second seating surface 22. The shape of the second seating surface 22 is not particularly limited, and may be a flat or curved shape, or may have an uneven portion.

The first cutting portion 5A located in the first pocket 9A has a cutting edge 11 located on the side of the first end 3A. When cutting a workpiece, the cutting edge 11 may be used in addition to the cutting edge 12a of the cutting insert 12 described above. The first cutting portion 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 portion 5A has a first insert 23 and a second cartridge 25.

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 rotation direction O2 of the first insert 23 and on the side of the first end 3A. 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 rotation direction O2 of the first insert 23 and on the side of the first end 3A 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 rotation direction O2 of the first insert 23 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 member in FIG. 4 as viewed from the A4 direction.

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, for example, as shown in a non-limiting example in Figure 7. Note that Figure 7 is a view of the member in Figure 4 as viewed from the A5 direction (as viewed from the first end 3A side).

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.

The first cutting portion 5A has a front surface 35. The front surface 35 is a surface located in front of the rotation direction O2 in the first cutting portion 5A. 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. In a non-limiting example shown in FIG. 6, the first side 37 is located on the side of the first end 3A, and the second side 39 is 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.

In a non-limiting example shown in Figure 6, the first cutting edge 27 is 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. Also, in a non-limiting example shown in Figure 6, the second cutting edge 29 is 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.

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 aligned 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.

The first cutting portion 5A has a rear surface 45. The rear surface 45 is a surface located rearward in the rotation direction O2 in the first cutting portion 5A. The rear surface 45 may be composed of a single member, or may be composed of multiple members as in the non-limiting example shown in FIG. 9. For example, as in the non-limiting example shown in FIG. 9, the rear surface 45 may be composed of a surface located rearward in the rotation direction O2 of the first insert 23 and the second cartridge 25. 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.

The first seating surface 21 is in contact with the rear surface 45, as in the non-limiting example shown in Figure 5. 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 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.

The first cutting portion 5A has a rear side surface 46. The rear side surface 46 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 side surface 46, and it may be, for example, a flat or curved shape, or may have an uneven portion. The rear side surface 46 of the first cutting portion 5A faces the second seating surface 22 of the first pocket 9A. At this time, the rear side surface 46 may be in contact with the second seating surface 22.

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 the state in which the member shown in FIG. 4 is cut along the line X-X shown in FIG. 6 during cutting. The X-X cross section is a cross section that passes through the center of the second cartridge 25 and is parallel to the rotation axis O1. The X-X cross 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 second seating surface 22 in the first pocket 9A and the rear side surface 46 in the first cutting portion 5A. At this time, the first elastic body 7A abuts against the second seating surface 22 and the rear side surface 46.

The first elastic body 7A can apply a biasing force to the first cutting portion 5A in a direction toward the second end 3B. In addition, the rear surface 45 can slide toward the second end 3B. Since the rear surface 45 is a part of the first cutting portion 5A, it can also be said that the first cutting portion 5A is slidable.

In a non-limiting example shown in FIG. 26, 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 process when it is located forward of the rotation axis O1 in the feed direction Y1. On the other hand, when the first cutting part 5A is located rearward of the rotation axis O1 in the feed direction Y1, it is desired that it does not contribute to the cutting process. This is because there is a risk that the machined surface will be damaged 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 of the rotation axis O1 in the feed direction Y1.

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, away from the second end 3B. This makes it easier for the first cutting portion 5A to be drawn into the workpiece, and cutting progresses. At this time, that is, the position of the first cutting edge 27 during cutting, is set to the first cutting edge position S1 (see FIG. 10).

Here, the cutting tool 1A according to the first embodiment has a first elastic body 7A. Therefore, when the first cutting portion 5A is located rearward in the feed direction Y1 relative to the rotation axis O1, the first elastic body 7A can apply a biasing force to the first cutting portion 5A in a direction toward the second end 3B. At this time, the rear surface 45 of the first cutting portion 5A can slide toward the second end 3B. Therefore, compared to when the first cutting portion 5A is located forward in the feed direction Y1 relative to the rotation axis O1, when the first cutting portion 5A is located rearward in the feed direction Y1 relative to the rotation axis O1, the first cutting portion 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 to the second cutting edge position S2 (see FIG. 11). Note that FIG. 11 corresponds to FIG. 10 and shows the state of the member 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.

When the first cutting portion 5A is positioned rearward of the rotation axis O1 in the feed direction Y1, 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.

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.

The above action reduces the risk of iris patterns. In addition, the above cutting process can be performed without tilting the rotation axis O1 of the cutting tool forward in the feed direction, so the processing direction is not limited to one direction and the travel distance of the tool can be reduced. Therefore, the above action is highly versatile and contributes to shortening processing time.

In the cutting tool 1A, the first insert 23 may be a so-called wiper insert. That is, while the cutting insert 12 performs normal milling on the workpiece, 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.

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

When the first elastic body 7A abuts against the second seating surface 22 and the rear side surface 46, the first elastic body 7A can efficiently apply a biasing force to the first cutting portion 5A, and therefore the relative position of the first cutting portion 5A (having the rear side surface 46) with respect to the main body portion 3 (having the second seating surface 22) can be easily moved toward the second end 3B. Also, the first elastic body 7A can easily move the relative position of the first cutting portion 5A (having the rear side surface 45) with respect to the main body portion 3 (having the first seating surface 21) toward the second end 3B.

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. In the cutting tool 1A according to the first embodiment, a helical spring 47 is used as an example of the first elastic body 7A, as shown in FIG. 10 and other non-limiting examples. For convenience of explanation of the cutting tool 1A according to the first embodiment, the first elastic body 7A is omitted in the drawings other than FIG. 10 and FIG. 11. 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 used integrally with the elastic member by being joined to 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. Examples of members other than the elastic member include a pin 48, as in the cutting tool 1C according to the third embodiment shown in FIG. 24 and other examples.

The elastic member described above is not limited to a specific material type. 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 greater than a specific value, but may be higher than, for example, the main body portion 3 and the first cutting portion 5A. The Young's modulus can be evaluated, for example, by the well-known nanoindentation method.

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 rubber and synthetic rubber.

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 not only be 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.

The rear surface 45, i.e., the first cutting portion 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) that slides in the direction of the second end 3B. Therefore, for example, in the process of sliding the first cutting portion 5A, it may move in a direction toward or away from the rotation axis O1, or may move forward or backward in the rotation direction O2.

The first seating surface 21 may be inclined forward in the rotational direction O2 as it approaches the second end 3B, as in a non-limiting example shown in Figure 5. In other words, the first seating surface 21 may be inclined backward in the rotational direction O2 as it approaches the first end 3A. In such a case, the cutting load received by the first seating 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 portion 3, due to 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 toward the workpiece, making it easier to cut the workpiece appropriately. Therefore, 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 is less likely to come into contact with the workpiece. Note that the inclination toward the front in the rotation direction O2 as it approaches the second end 3B does not necessarily mean that it continues to incline strictly, and may include a portion that is parallel to the rotation axis O1.

As shown in a non-limiting example in FIG. 10, the second seating surface 22 may have a first recess 49, and the rear side surface 46 may have a second recess 51. The second recess 51 faces the first recess 49. The first elastic body 7A is inserted into the first recess 49 and the second recess 51. The first elastic body 7A is 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, the first seating surface 21 and the rear surface 45 are easily brought into contact while the first elastic body 7A is positioned between the main body 3 and the first cutting portion 5A. When the first elastic body 7A is in contact with the first recess 49 and the second recess 51, the biasing force can be efficiently transmitted to the first cutting portion 5A.

In the above, "the second recess 51 faces the first recess 49" 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 entire opening 49A of the first recess 49 and the entire opening 51A of the second recess 51 do not need to face each other.

The shape of the first recess 49 is not particularly limited, and the width and depth of the first recess 49 are also not limited. The width of the first recess 49 may be constant or may vary.

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.

The first elastic body 7A may be attached to the first recess 49. Here, there is no particular limitation on the method of attachment. For example, in a non-limiting example shown in FIG. 10, the helical spring 47 is a tension spring, and is attached to the first recess 49 and the second recess 51 via hooks. By attaching the first elastic body 7A to the first recess 49, it is possible for the first elastic body 7A to slide in a direction along the central axis N1 of the first elastic body 7A. Note that the first elastic body 7A may be attached to the second recess 51, and as in 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.

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 or curved shape. 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.

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 or curved shape. In addition, the width and height of the first convex portion 55 do not have to be constant. Note that FIG. 9 is an oblique view of the first cutting portion 5A viewed from the side of the rear surface 45.

In addition, 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 groove 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 linear in shape so as to correspond to the first groove 53, as in the 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.

As shown in a non-limiting example 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 such a case, the cutting edge 11 moves toward the first end 3A during cutting and also 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 strictly continuing to approach, and may include a portion parallel to the rotation axis O1.

As shown in a non-limiting example in FIG. 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, and may include a portion that is parallel to the rotation axis O1.

As shown in a non-limiting example 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. Furthermore, 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.

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 stabilized. 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 or curved shape. In addition, the width and height of the second convex portion 59 do not have to be constant.

In addition, 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 linear in shape to correspond to the second grooves 57, as in the 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.

As shown in a non-limiting example 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 also 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 strictly continuing to approach, and may include a portion parallel to the rotation axis O1.

As shown in a non-limiting example in FIG. 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, and may include a portion that is parallel to the rotation axis O1.

The first groove 53 may extend along the central axis N1 of the first elastic body 7A. In other words, the central axis N1 of the first elastic body 7A may extend along the direction in which the first groove 53 extends. For example, as shown in a non-limiting example in FIG. 11, the central axis N3 of the first groove 53 and the central axis N1 of the first elastic body 7A may be parallel. However, the fact that the two central axes are parallel does not mean that the angle between the central axis N3 and the central axis N1 is strictly 0°. If the angle between the central axis N3 and the central axis N1 is -5° to 5°, the two virtual lines may be considered to be parallel. For example, as shown in a non-limiting example in FIG. 11, when the central axis N3 of the first groove 53 approaches the rotation axis O1 as it approaches the second end 3B, the central axis N1 of the first elastic body 7A may approach the rotation axis O1 as it approaches the second end 3B.

As shown in a non-limiting example in FIG. 11, the central axis N3 of the first groove 53 and the central axis N4 of the rear surface 45 may coincide. That is, the rear surface 45 may extend along the central axis N1 of the first elastic body 7A. Also, when the main body 3 is viewed from the A4 direction (front view), the rear surface 45 or the first groove 53 may extend along the central axis N1 of the first elastic body 7A. In such a case, since the direction of the biasing force applied from the first elastic body 7A coincides with the sliding direction of the rear surface 45, the first elastic body 7A can efficiently apply a biasing force to the first cutting portion 5A. The above content may be applied to the second groove 57 instead of the first groove 53. That is, the central axis N1 of the first elastic body 7A may extend along the direction in which the second groove 57 extends.

The first seating surface 21 may have a protrusion 60 (see FIG. 8). The protrusion 60 may be located on the side of the first end 3A. The protrusion 60 may protrude forward in the rotation direction O2 of the rotation axis O1. With this configuration, when the first cutting part 5A moves to the second cutting edge position S2 during cutting, the first cutting part 5A comes into contact with the protrusion 60, thereby preventing the first cutting part 5A from moving excessively toward the second end 3B. In addition, the load applied from the first cutting part 5A to the first elastic body 7A toward the second end 3B is reduced, and the risk of damage to the first elastic body 7A can be reduced.

The protrusion 60 may be located closer to the first end 3A than the first cutting portion 5A, as in the non-limiting example shown in Fig. 8, or may be located at the center of the first seating surface 21. There is no particular limitation on the shape of the protrusion 60, and it may be, for example, a linear shape extending along the radial direction of the rotation axis O1, as in the non-limiting example shown in Fig. 8.

The rear surface 45 may have a recess 61 (see FIG. 9). The recess 61 may be located on the side of the first end 3A. The recess 61 may be recessed toward the front of the rotation direction O2 of the rotation axis O1 on the rear surface 45. The recess 61 may be composed of a single member, or may be composed of multiple members as in the non-limiting example shown in FIG. 9. For example, as in the non-limiting example shown in FIG. 9, the recess 61 may be composed of the first insert 23 and the second cartridge 25. It is not necessary for the entire periphery of the recess 61 to be surrounded by a member, and only a portion of the periphery of the recess 61 may be surrounded by a member.

The protrusion 60 may be inserted into the recess 61. By inserting the protrusion 60 into the recess 61, the first cutting portion 5A can easily come into contact with the protrusion 60. Although there is no particular limitation on the shape of the recess 61, it is desirable that the shape of the recess 61 corresponds to the shape of the protrusion 60 in terms of increasing the contact area with the protrusion 60. In such a case, the first cutting portion 5A can easily come into contact with the protrusion 60. For example, when the protrusion 60 and the recess 61 have a linear shape extending along the radial direction of the rotation axis O1 as shown in FIG. 8 and FIG. 9, the contact area of the protrusion 60 and the recess 61 increases, and the load applied from the first cutting portion 5A to the first elastic body 7A on the side of the second end 3B is further reduced.

The recess 61 may be located in the center of the rear surface 45. In that case, the protrusion 60 may be located in the center of the first seating surface 21, and the width of the protrusion 60 may be configured to be smaller than the width of the recess 61 groove in the direction along the rotation axis O1 to an extent that the rear surface 45 can slide toward the second end 3B.

The first cutting portion 5A may have a first through hole 62. The first through hole 62 may open on the front surface 35 and the rear surface 45. The first cutting portion 5A may also have a third fastener 63 fixed to the main body portion 3, as in a non-limiting example shown in FIG. 6. The third fastener 63 may be inserted into the first through hole 62. An example of the third fastener 63 is a screw. It is sufficient for the third fastener 63 to maintain the first cutting portion 5A in the pocket 9.

Because the first cutting part 5A is slidable, it is not necessary for the first cutting part 5A to be completely fixed to the main body part 3 by the third fixing device 63. By providing the first cutting part 5A with this configuration, it is possible to stably hold the first cutting part 5A while keeping it in a slidable state. Note that the first cutting part 5A may have a recess that does not penetrate the main body part 3 instead of the first through hole 62, and the first cutting part 5A may be fixed to the main body part 3 by fitting into the recess.

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 device 63 may be inserted into the third recess 64 through the first through hole 62 of the first cutting portion 5A.

The cutting tool 1B according to the second embodiment includes a main body 3, a first cutting portion 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 is omitted. Figure 16 is a view of the cutting tool 1B according to the second embodiment, corresponding to Figure 10.

While the first elastic body 7A in the cutting tool 1A of the first embodiment is constituted by a helical spring 47, the first elastic body 7A in the cutting tool 1B of the second embodiment is constituted by a material having a high Young's modulus.

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 the non-limiting example of FIG 16. The end surface of the columnar first elastic body 7A may be polygonal or circular.

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 Figures 17 to 25. 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. For convenience of explanation of the cutting tool 1C of the third embodiment, the first elastic body 7A is omitted in the drawings other than Figures 24 and 25. Note that Figure 24 is an enlarged cross-sectional view of the cutting tool 1C of the third embodiment cut along the line XXIV-XXIV in Figure 22. The XXIV-XXIV cross section is a cross section passing through the center of the second cartridge 25 and parallel to the rotation axis O1.

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 (first groove 53 or second groove 57), which allows the first cutting part 5A to slide linearly. On the other hand, the cutting tool 1C according to the third embodiment is rotatable about the central axis (rotation axis O3) of the third fixture 63, as in a non-limiting example shown in FIG. 20 etc. In other words, the first cutting part 5A can slide around the third fixture 63.

The cutting tool 1C may further include a bearing member 65 between the body 3 and the first cutting portion 5A, as shown in a non-limiting example in Figures 20 to 24. When the cutting tool 1C includes such a member, the first cutting portion 5A can slide smoothly around the third fixture 63.

The bearing member 65 may be located between the first through hole 62 and the third fixture 63. Such a configuration of the cutting tool 1C allows the first cutting portion 5A to slide smoothly around the third fixture 63. As shown in a non-limiting example in FIG. 20, in the cutting tool 1C, the first through hole 62 may open on a surface of the first cutting portion 5A that is closer to the rotation axis O1 and a surface that is farther from the rotation axis O1.

In the cutting tool 1C, during cutting, the first cutting part 5A may rotate in the rotation direction O4 of the rotation axis O3, and the first cutting edge 27 may move to the first cutting edge position S1. On the other hand, during non-cutting, the first cutting part 5A may rotate in the rotation direction O5 of the rotation axis O3, and the first cutting edge 27 may move to the 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. Note that, as shown in a non-limiting example in FIG. 20, the rotation direction O4 and the rotation direction O5 are in a mutually opposite relationship in the rotation direction of the rotation axis O3.

21, when the cutting tool 1C 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. By configuring the cutting tool 1C in this manner, the first cutting edge 27 is more likely to move toward the first end 3A during cutting. In other words, 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.

Materials for the cutting insert 12 and the first insert 23 include, for example, cemented carbide and cermet. Examples of cemented carbide compositions 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. 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.

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).

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.

Materials that can be used for the base body 13 include steel, cast iron, and aluminum alloys. From the viewpoint of increasing toughness, steel may be used as the material for the base body 13.

The cutting tools 1A to 1C of the present disclosure include a main body portion 3, a cutting portion 5, and a biasing means. The biasing means is located between the main body portion 3 and the first cutting portion 5A, and is an element capable of applying a biasing force to the first cutting portion 5A in a direction toward the second end 3B. The biasing means may be located between the second seating surface 22 and the rear side surface 46. 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.

In the cutting tools 1A to 1C of the present disclosure, the first cutting portion 5A can slide toward the second end 3B due to the biasing force applied by the biasing means, i.e., the first elastic body 7A. Therefore, compared to when the first cutting portion 5A is positioned forward in the feed direction Y1 relative to the rotation axis, when the first cutting portion 5A is positioned rearward in the feed direction Y1 relative to the rotation axis, the first cutting portion 5A can slide toward the second end 3B. In other words, a biasing force is applied from the biasing means to the first cutting portion 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.

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 first cutting part 5A can cut the workpiece, but when the first cutting part 5A is located rearward in the feed direction Y1 relative to the rotation axis, the first cutting part 5A is less likely to cut the workpiece. This reduces the risk of iris patterns.

<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 non-limiting first embodiment described above as an example. The description will be given below with reference to Figs. 26 to 28. Figs. 26 to 28 illustrate the steps of cutting a workpiece 102 as a non-limiting example of a method for manufacturing a machined product 101. To facilitate visual understanding, the machined parts are hatched in Figs. 27 and 28.

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

(1) The cutting tool 1A may be rotated in a rotation direction O2 around a rotation axis O1 and brought closer to the workpiece 102 in a feed direction Y1 (see Figure 26).

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

(2) The cutting tool 1A may be brought even closer to the workpiece 102, so that the rotating cutting tool 1A contacts the desired position on the surface of the workpiece 102 to cut the workpiece 102 (see Figure 27).

In this process, the cutting edge 11 may be brought into contact with a desired position on the surface of the workpiece 102.

(3) The cutting tool 1A may be moved away from the workpiece 102 in the Y2 direction (see Figure 28).

In this process, similarly to the process (1) described above, 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. In addition to the milling process shown in FIG. 28 as a non-limiting example, the cutting process may also include plunge machining, copy machining, and oblique sinking.

By going through the above processes, it is possible to achieve excellent processability.

In addition, when the cutting process of the workpiece 102 as described above is performed multiple times, for example, when multiple cutting processes are performed 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 rotated may be repeated.

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

1A to 1C: Cutting tool O1, O3: Rotation axis O2, O4, O5: Rotation direction 3: Main body 3A: Tip (first end)
3B... Rear end (second end)
Reference Signs List 5: Cutting portion 5A: First cutting portion 7: Elastic body 7A: First elastic body 9: Pocket 9A: First pocket 11: Cutting edge 12: Cutting insert 12a: Cutting edge 13: Base 15: First cartridge 17: First hole 19: First fastener 21: First seating surface 22: Second seating surface 23: First insert 25: Second cartridge 27: First cutting edge 29: Second cutting edge 31: Second hole 33: Second fastener 35: Front surface 37: First side 39: Second side 41: First corner 43: Third cutting edge 45: Rear surface 46: Rear side N1, N2, N3, N4: Central axis Y1: Feed direction S1: First cutting edge position S2: Second cutting edge position 47: Helical spring 48: Pin Reference Signs List 49: First recess 49A: Opening 51: Second recess 51A: Opening 53: First groove 55: First protrusion 57: Second groove 59: Second protrusion 60: Protrusion 61: Depression 62: First through hole 63: Third fixture 64: Third recess 65: Bearing member 101: Machined product 102: Workpiece

Claims (14)

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 is
A first seating surface facing forward in a rotation direction of the rotation shaft;
A second seating surface facing the tip,
The cutting portion is
a rear surface located rearward in a rotation direction of the rotation shaft and in contact with the first seating surface;
a rear side surface located on the rear end side and facing the second seating surface,
The elastic body abuts against the second seating surface and the rear side surface,
the rear surface is slidable toward the rear end;
The first seating surface is inclined forward in the rotation direction toward the rear end . The second seating surface has a first recess,
the rear side 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. The first seating surface has a first groove extending from the front end side toward the rear end side,
The cutting tool of claim 1 , wherein the rear surface has a first protrusion inserted into the first groove. The cutting tool according to claim 3 , wherein the first groove approaches the rotation axis as it approaches the rear end. The cutting tool according to claim 3 , wherein a central axis of the elastic body extends along a direction in which the first groove extends. 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. The cutting tool according to claim 6 , wherein the second groove approaches the rotation axis as it approaches the rear end. The cutting tool according to claim 6 , wherein a central axis of the elastic body extends along a direction in which the second groove extends. The cutting tool according to claim 1, wherein the first seating surface is located on the side of the tip and has a protruding portion that protrudes forward in the direction of rotation of the rotating shaft. The cutting tool according to claim 9 , wherein the protrusion has a linear shape extending along a radial direction of the rotation shaft. The cutting tool according to claim 1, wherein the rear surface is located on the side of the tip and has a recess that is recessed forward in the rotation direction of the rotating shaft, and the recess has a linear shape that extends along the radial direction of the rotating shaft. 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 inserted into the through hole and fixed to the body portion. 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,
The pocket has a second seating surface facing the tip,
The cutting portion is located on the rear end side and has a rear side surface facing the second seating surface,
The biasing means is located between the second seat surface and the rear side surface,
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. A step of rotating the cutting tool according to any one of claims 1 to 13 ;
contacting the cutting tool with a workpiece;
and removing the cutting tool from the workpiece.

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