Cutting tool and method for manufacturing cut product

Abstract

To provide a cutting tool having high workability and capable of reducing the occurrence of chattering vibration during cutting.SOLUTION: A cutting tool 1 includes: a body part 3 with pockets 9; cutting parts 5 with cutting blades 11; and fasteners 7 to be fixed to the body part 3. The pocket 9 has a seating surface, and a restraining lateral surface positioned near a rotary shaft relative to the seating surface. The cutting part includes: a rear surface facing the seating surface; an inside surface facing the restraining lateral surface; a first outside surface positioned on an opposite side to the inside surface; and a second outside surface which is positioned on a side closer to a rear end than the first outside surface, and is in contact with a fastener. The rear surface includes: an outside region which is positioned on an outer peripheral side and is in contact with the seating surface; and an inside region which is connected to the inside surface and the outside region and is separated from the seating surface.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] 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]

[0002] As cutting tools, for example, the milling tools described in Patent Documents 1 and 2 are known. In the milling tools described in Patent Documents 1 and 2, a cartridge (cutting blade member) having a cutting blade such as a cutting insert is attached to the tool body. The milling tool described in Patent Document 1 has an attachment groove whose mouth is narrow in the direction of centrifugal force. The cartridge is fastened and fixed to the tool body by this attachment groove and attachment bolt. This makes it possible to prevent the cutting blade tip and components from scattering due to centrifugal force. Also, in the milling tool described in Patent Document 2, the cutting blade member is pressed and fixed against the inner surface of the insertion hole by a clamp screw. This fixes the orientation around the axis in the insertion hole, allowing stable cutting processing to be performed. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2002-011612 A [Patent Document 2] JP 2002-331412 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the milling tool described in Patent Document 1, the cartridge is fixed by the mounting bolt only in the direction in which the centrifugal force is applied. Therefore, when a cutting load is applied from the front to the rear in the rotation direction during cutting, so-called chatter vibration may occur. On the other hand, in the milling tool described in Patent Document 2, the cutting blade member is pressed and fixed against the inner surface of the insertion hole by the clamp screw from the front in the rotation direction of the axis. Therefore, it takes time to attach the clamp screw, and as a result, there is a risk of reducing the processing efficiency.

[0005] The present disclosure has been made in consideration of the above-mentioned problems, and has an object to provide a cutting tool that is easy to use and can reduce the occurrence of chatter vibration during cutting. [Means for solving the problem]

[0006] 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 axis 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 a fastener for fastening the cutting portion to the body portion. The pocket has a seating surface facing forward in the rotation direction of the rotation axis and a constraint side surface located near the rotation axis relative to the seating surface. The cutting portion has a back surface facing the seating surface, an inner surface facing the constraint side surface, a first outer surface located opposite the inner surface, and a second outer surface located on the rear end side of the first outer surface and in contact with the fastener. The back surface has an outer region located on the outer periphery side and in contact with the seating surface, and an inner region connected to the inner surface and the outer region and separated from the seating surface. Effect of the Invention

[0007] The above-described cutting tool has high workability and can reduce the occurrence of chatter vibration during cutting. [Brief description of the drawings]

[0008] [Figure 1] 1 is a perspective view showing a cutting tool according to an 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] FIG. 4 is an enlarged view showing a part of a main body according to the embodiment. [Diagram 5] 2 is an enlarged view showing a main body, a first cutting part, a first fixture, and the like of the cutting tool shown in FIG. 1. [Figure 6] 6 is a plan view of the cutting tool shown in FIG. 5 as viewed from a direction A3. [Figure 7] 7 is a perspective view showing the cutting tool shown in FIG. 6 in a state where a first cutting part is not clamped by a first fastener. FIG. [Figure 8] 7 is a perspective view showing a state in which a first cutting part is clamped by a first fastener in the cutting tool shown in FIG. 6. FIG. [Figure 9] FIG. 2 is a perspective view showing a first cutting portion and the like according to the embodiment. [Figure 10] 10 is a plan view of the first cutting portion and the like in FIG. 9 as viewed from the A4 direction. [Figure 11] 10 is a plan view of the first cutting portion etc. in FIG. 9 as viewed from the A5 direction. [Figure 12] FIG. 3 is an enlarged view of the XII-XII cross section shown in FIG. [Figure 13] FIG. 3 is an enlarged view of the XIII-XIII cross section shown in FIG. [Figure 14] FIG. 2 is a schematic explanatory diagram showing one step of a method for producing a machined product according to one embodiment. [Figure 15] FIG. 2 is a schematic explanatory diagram showing one step of a method for producing a machined product according to one embodiment. [Figure 16] 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 tool 1 of the embodiment will be described in detail with reference to the drawings. However, for the sake of convenience, each of the drawings referred to below shows only the main members necessary for explaining the embodiment in a simplified manner. Therefore, the cutting tool 1 of the present disclosure may include any component member not shown in each of 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.

[0010] As shown in Fig. 1, the cutting tool 1 according to the embodiment has a rotation axis O1 and is a so-called rotating tool. Examples of the rotating tool include a milling tool and an end mill. The rotating tool shown in the figure is a milling tool. The rotation axis O1 is an axis about which the cutting tool 1 rotates, and is not a tangible object of the cutting tool 1.

[0011] As shown in FIG. 1 and other figures, the cutting tool 1 includes a main body 3, a cutting part 5, and a fixture 7. The main body 3 extends from a tip 3A to a rear end 3B along a rotation axis O1. As shown in FIG. 2, the main body 3 has a pocket 9 located on the tip 3A side. FIG. 2 is a side view of the cutting tool 1 shown in FIG. 1 as viewed from the A1 direction. The cutting part 5 is located in the pocket 9 and has a cutting edge 11 located on the tip 3A side. The fixture 7 is a member used to fix the cutting part 5 to the main body 3, and is a screw in the example shown in FIG. 1 and other figures. In the following description, unless otherwise specified, the cutting tool 1 will be shown in a state in which the cutting part 5 is fastened by the fixture 7.

[0012] The main body 3 is a base portion of the cutting tool 1. There may be only one pocket 9, or there may be multiple pockets 9 as shown in FIG. 3. FIG. 3 is a view of the cutting tool 1 shown in FIG. 1 as viewed from the A2 direction (the tip 3A side). When the main body 3 has multiple pockets 9, one of the multiple pockets 9 is designated as a first pocket 9A. The number of cutting portions 5 is not particularly limited, and may be multiple as shown in FIG. 3. When the main body 3 has multiple pockets 9, the first pocket 9A is designated as a first pocket 9A. The cutting portion 5 located in the pocket 9A is defined as the first cutting portion 5A. The number of fasteners 7 is not particularly limited, and may be multiple as shown in FIG. 1. When the cutting tool 1 has multiple fasteners 7, the fastener 7 that fastens the first cutting portion 5A to the main body portion 3 is defined as the first fastener 7A. In an example shown in FIG. 5 etc., the first fastener 7A may be a first screw.

[0013] The rotation direction O2 is not limited to the direction shown in Fig. 1. For example, when the cutting tool 1 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.

[0014] In the example shown in FIG. 1, the cutting tool 1 has a disk 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, respectively. As is clear from the fact that the cutting tool 1 has a first pocket 9A and the like, the cutting tool 1 is not strictly disk-shaped. The length of the main body 3 in the direction along the rotation axis O1 is, for example, 40 mm to 80 mm. The outer diameter of the main body 3 in the direction perpendicular to the rotation axis O1 is, for example, 40 mm to 350 mm.

[0015] The main body 3 can rotate 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 conical, and may have irregularities. The main body 3 may be composed of multiple members, or may be composed of a single member.

[0016] As shown in Fig. 6, the first pocket 9A has a seating surface 13 facing forward in the rotational direction O2 of the rotation axis O1. In other words, the main body 3 has the seating surface 13. The seating surface 13 may be located on the side of the first end 3A of the main body 3. The shape of the seating surface 13 is not limited to the planar shape shown in Fig. 4, and may be a curved shape or may have uneven portions. Fig. 6 is a view of the cutting tool 1 shown in Fig. 5 as viewed from the A3 direction (the side of the first end 3A).

[0017] The first pocket 9A has a constraining side surface 15 located closer to the rotation axis O1 than the seat surface 13. In other words, it may be said that the main body portion 3 has the constraining side surface 15. The constraining side surface 15 may face in a direction away from the rotation axis O1, that is, toward the outer periphery. The shape of the constraining side surface 15 is not particularly limited, and may be a flat shape or a curved shape, and may have uneven portions.

[0018] 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 using this cutting edge 11. The first cutting part 5A may be composed of a plurality of members or may be composed of a single member. The first cutting part 5A in the example shown in FIG. 5 has a cutting insert 17 and a cartridge 19.

[0019] In an example shown in FIG. 5, the cutting insert 17 has a cutting edge 11. The cutting edge 11 is located in front of the rotation direction O2 of the cutting insert 17 and on the side of the first end 3A. The cutting edge 11 does not need to be located only in this portion. For example, when the cutting edge 11 located in front of the rotation direction O2 of the cutting insert 17 and on the side of the first end 3A is defined as the first cutting edge 21, the cutting insert 17 may further have a second cutting edge 23 located in front of the rotation direction O2 of the cutting insert 17 and on the outer periphery side. In an example shown in FIG. 5, the first cutting edge 21 and the second cutting edge 23 are located on the outer periphery side of the cutting insert 17. The first cutting edge 21 and the second cutting edge 23 are not limited to a straight shape as shown in FIG. 5 and the like, and may be a gentle curved shape.

[0020] The cutting insert 17 is provided with a first end 3A side, an outer circumferential side, and a , and is located forward in the rotation direction O2. The cutting insert 17 may be brazed to the cartridge 19, for example, or may have an insert hole 25 and be fixed to the cartridge 19 by an insert fixing tool 27 such as a screw, as shown in an example in FIG.

[0021] The length of the first cutting portion 5A in the direction along the rotation axis O1 is, for example, 1 mm to 10 mm.The length of the first cutting portion 5A in the radial direction of the rotation axis O1 is, for example, 0.5 mm to 10 mm.

[0022] The first cutting part 5A may have a front surface 29. The front surface 29 is a surface of the first cutting part 5A that is located forward in the rotational direction O2. The front surface 29 may be formed by the cutting insert 17 as shown in Fig. 5. There is no particular limitation on the shape of the front surface 29, and it may be, for example, a flat or curved shape, or may have an uneven portion.

[0023] The front surface 29 may have a first side 31, a second side 33, and a first corner 35. In the example shown in Fig. 5, the first side 31 is located on the side of the first end 3A. In the example shown in Fig. 5, the second side 33 is located on the outer periphery side away from the rotation axis O1, and the first corner 35 is a corner connected to the first side 31 and the second side 33. Note that the corner here is not limited to a point where two sides intersect, but may be a region where two sides intersect macroscopically, and may be a curved shape or a straight line shape inclined with respect to each of the two sides microscopically.

[0024] 5, the first cutting edge 21 may be located on the first side 31. As described above, since the first side 31 is located on the side of the first end 3A, the first cutting edge 21 located on the first side 31 can be located on the side of the first end 3A in the cutting portion 5. Furthermore, the second cutting edge 23 may be located on the second side 33. As described above, since the second side 33 is located on the side away from the rotation axis O1, the second cutting edge 23 located on the second side 33 can be located on the side away from the rotation axis O1 in the cutting portion 5.

[0025] The first cutting portion 5A may have a third cutting edge 36 located at the first corner 35. The third cutting edge 36 may be connected to the first cutting edge 21 and the second cutting edge 23. The third cutting edge 36 is not limited to a curved shape, and may have a straight line portion or may be an arc shape.

[0026] The first cutting portion 5A has a back surface 37 facing the seat surface 13. Since the seat surface 13 faces forward in the rotation direction O2 of the rotation axis O1, the back surface 37 may be said to face backward in the rotation direction O2 of the rotation axis O1. The back surface 37 may be located on the side of the first end 3A of the main body 3. The shape of the back surface 37 is not particularly limited, and may be flat or curved, or may have uneven portions.

[0027] The first cutting portion 5A has an inner side surface 39 located near the rotation axis O1 with respect to the seat surface 13. The inner side surface 39 may face the constraint side surface 15. Since the constraint side surface 15 faces the outer periphery side, it can be said that the inner side surface 39 faces in the direction toward the rotation axis O1, that is, toward the inner periphery side.

[0028] As shown in FIG. 5, the first cutting portion 5A has a first outer surface 41 located on the opposite side to the inner surface 39. The first outer surface 41 may face the outer periphery side, and may have a second outer surface 43. The first cutting portion 5A may also have a second outer surface 43. The second outer surface 43 may be located closer to the second end than the first outer surface 41. The second outer surface 43 may be a flat surface. The first fixing tool 7A can come into contact with the second outer surface 43. More specifically, the screw head 45 of the first fixing tool 7A can come into contact with the second outer surface 43.

[0029] The first cutting portion 5A may have a through hole 47. The through hole 47 is formed on the inner surface 39 and the second outer surface 48. 7 and 8. The through hole 47 may be open at the surface 43. The first fastener 7A may be inserted into the through hole 47. The through hole 47 may extend from the outer periphery side to the inner periphery side so that the first fastener 7A can be easily inserted from the outer periphery side. The shape of the through hole 47 is not limited to the shape shown in FIG. 7 and the like.

[0030] The first pocket 9A may have a screw hole 48. In other words, the restraining side surface 15 (main body portion 3) may have the screw hole 48. The screw hole 48 may open toward the outer periphery. As shown in FIG. 7 and other figures, when the first cutting portion 5A has a through hole 47, the first fastener 7A may be inserted into the screw hole 48 through the through hole 47, and the first cutting portion 5A may be fixed to the main body portion 3.

[0031] The first cutting part 5A may have a central axis N1. Here, the central axis N1 is not a tangible object of the first cutting part 5A. In addition, when the first cutting part 5A is fixed to the main body part 3, the first cutting part 5A may rotate about the central axis N1. The shape of the first cutting part 5A is not particularly limited, and in FIG. 9, the first cutting part 5A has a substantially cylindrical shape.

[0032] The back surface 37 may be in contact with the seating surface 13 as shown in Fig. 6 etc. In such a case, the seating surface 13 can receive the cutting load applied to the first cutting portion 5A through the back surface 37, so cutting can be performed stably. Note that the entire seating surface 13 and the back surface 37 do not need to be in contact with each other, and for example, as shown in Fig. 6, only a part of the seating surface 13 and the back surface 37 may be in contact with each other.

[0033] The back surface 37 has an outer region 49 and an inner region 51. Here, the outer region 49 refers to a region of the back surface 37 that is located on the outer periphery side and in contact with the seating surface 13 as shown in Fig. 6. The inner region 51 refers to a region of the back surface 37 that is connected to the inner side surface 39 and the outer region 49 and is separated from the seating surface 13.

[0034] When viewed from the first end 3A side, a virtual straight line L1 is set that passes through an end point of the cutting insert 17 closer to the rotation axis O1 and is perpendicular to the front surface 29. The outer region 49 may be entirely located on the outer periphery side of the virtual straight line L1. Moreover, the inner region 51 may intersect with the virtual straight line L1.

[0035] When fixing the first cutting part 5A to the main body part 3, first, as shown in Fig. 7, the first fixing tool 7A is inserted into the screw hole 48 through the through hole 47. That is, Fig. 7 shows a state in the middle of fixing the first cutting part 5A to the main body part 3 using the first fixing tool 7A. Fig. 7 shows a state in which the first fixing tool 7A is not completely inserted into the screw hole 48, but a part of the first fixing tool 7A near the bottom part 53 is inserted into the screw hole 48.

[0036] 7 shows a state in which, when the first fastener 7A inserted into the screw hole 48 is screwed, the screw head 45 of the first fastener 7A comes into contact with the second outer surface 43 and a load caused by screw tightening begins to be applied to the first cutting portion 5A. At this time, the screw head 45 comes into contact with the second outer surface 43 rearward of the central axis N1 of the first cutting portion 5A in the rotation direction O2 of the rotation axis O1, and the screw head 45 is separated from the second outer surface 43 forward of the central axis N1 of the first cutting portion 5A in the rotation direction O2 of the rotation axis O1.

[0037] 8 shows a state in which the first cutting part 5A is fastened by the first fastener 7A inserted into the screw hole 48. As described above, the first cutting part 5A is rotatable around the central axis N1. Therefore, when the first fastener 7A is fastened with the screw head 45 and the second outer surface 43 in contact with each other as shown in FIG. 7, the first cutting part 5A rotates clockwise around the central axis N1 as shown in FIG.

[0038] As the first cutting portion 5A rotates clockwise around the central axis N1, an inner peripheral portion of the back surface 37 moves away from the seating surface 13, and an outer peripheral portion of the back surface 37 is pressed against the seating surface 13. As a result, as shown in Fig. 8, when the first cutting portion 5A is fastened by the first fastener 7A, the back surface 37 can have an outer region 49 in contact with the seating surface 13 and an inner region 51 away from the seating surface 13. The outer region 49 and the seating surface 13 may be in surface contact or point contact.

[0039] The impulse of the cutting load received by the cutting edge 11 of the first cutting portion 5A and transmitted to the main body 3 becomes larger toward the outer periphery side away from the rotation axis O1. In this case, in the example cutting tool 1 shown in Fig. 6, since the outer region 49 of the back surface 37 is in contact with the seating surface 13, the large impulse of the cutting load generated by the cutting edge 11 can be stably received by the main body 3.

[0040] This is because the outer peripheral portion of the back surface 37 is pressed against the seating surface 13, and therefore, even when the cutting load fluctuates, the outer peripheral portion of the back surface 37 is unlikely to separate from the seating surface 13. Since the outer peripheral portion of the back surface 37 is in stable contact with the seating surface 13, the cutting load of a large impulse generated by the cutting edge 11 can be stably received by the main body 3.

[0041] In particular, in the example shown in Figure 6, since the cutting edge 11 is located on the outer periphery of the first cutting portion 5A, the cutting load can be stably transmitted to the main body portion 3 in the outer region 49, which is the portion of the back surface 37 that is located rearward of the cutting edge 11 in the rotational direction O2.

[0042] The above-mentioned effect can be achieved even when there is no through hole 47. Specifically, when the first fastener 7A is a set screw, the first fastener 7A may be tightened to press a portion of the bottom 53 of the first fastener 7A located rearward in the rotation direction O2 of the rotation axis O1 against the second outer side surface 43, thereby pressing the back surface 37 against the seating surface 13. In such a case, during cutting, the main body 3 can stably receive the cutting load applied to the first cutting portion 5A through the contact portion between the back surface 37 and the seating surface 13, thereby reducing the occurrence of chatter vibration.

[0043] If the entire back surface 37, i.e., both the inner region 51 and the outer region 49 of the back surface 37, are configured to be in contact with the seating surface 13, there is a risk that, due to manufacturing variations in the first cutting portion 5A and the main body portion 3, the inner region 51 will come into contact with the seating surface 13 while the outer region 49 will move away from the seating surface 13 when the first cutting portion 5A is fastened to the main body portion 3 by the first fastener 7A. Even if both the inner region 51 and the outer region 49 are in contact with the seating surface 13 when the first cutting portion 5A is fastened to the main body portion 3 by the first fastener 7A, there is a risk that, due to variations in cutting load, the inner region 51 will come into contact with the seating surface 13 while the outer region 49 will move away from the seating surface 13.

[0044] 8, however, since the inner region 51 of the back surface 37 is separated from the seating surface 13, the outer region 49 of the back surface 37 is likely to stably contact the seating surface 13. Also, since there is a certain gap between the inner region 51 and the seating surface 13, the first cutting portion 5A can be easily attached to the main body 3. Note that there may be a gap of 0.2 mm to 1 mm between the seating surface 13 and the inner region 51.

[0045] In addition, when the ridge line located on the side of first end 3A in the outer region 49 is defined as outer ridge line 55, and the ridge line located on the side of first end 3A in the inner region 51 is defined as inner ridge line 57, as shown in Figure 6, outer ridge line 55 may be in contact with seat surface 13, and inner ridge line 57 may be separated from seat surface 13.

[0046] The first cutting part 5A may have a cutting hole 59 facing the insert hole 25. The insert fixing tool 27 may be inserted into the cutting hole 59 through the insert hole 25 to fix the cutting insert 17 to the cartridge 19. The cutting hole 59 is not limited to a so-called blind hole, and may penetrate to the back surface 37 as shown in Fig. 10. Fig. 10 is a view of the first cutting part 5A etc. in Fig. 9 as viewed from the A4 direction.

[0047] When the cutting tool 1 is seen through from the first end 3A side, the outer region 49 may be located behind the cutting insert 17 or behind the first cutting edge 21, as shown in Fig. 8. In such a case, the seating surface 13 can stably receive the cutting load applied to the first cutting portion 5A through the back surface 37.

[0048] 8, the outer region 49 may contact the seat surface 13 behind the insert hole 25. In other words, the outer region 49 may contact the seat surface 13 behind the machined hole 59. Specifically, as shown in FIG. 8, when viewed from the first end 3A side in a plan view, the seat surface 13 may contact a region (hereinafter referred to as a "two-point region S1") located between two intersections between the seat surface 13 and two imaginary extension lines extending from both ends of the machined hole 59 on the back surface 37.

[0049] When viewed from the first end 3A side, the back surface 37 and the seating surface 13 may be in contact with each other in the area S1 between the two points. In other words, the outer area 49 may be located in the area S1 between the two points. In such a case, the seating surface 13 can more stably receive the cutting load applied to the first cutting portion 5A through the back surface 37.

[0050] There are no particular limitations on the shapes of the outer region 49 and the inner region 51. For example, the inner region 51 may be flat. However, even in such a case, the boundary between the outer region 49 and the inner region 51 may be a curved surface.

[0051] The pocket 9 may have a curved portion 61 that has a curved surface shape. In other words, the main body 3 may have the curved portion 61. When viewed from the first end 3A side, the curved portion 61 may have a curved shape or a concave shape. Moreover, the curved portion 61 may be located closer to the rotation axis O1 than the seating surface 13 and may be adjacent to the seating surface 13, or may be located between the seating surface 13 and the restraining surface 15 as shown in FIG. 4.

[0052] The curved portion 61 may be spaced apart from the first cutting portion 5A. When the pocket 9 has the curved portion 61, it is possible to reduce the risk that the pocket 9 of the main body 3 and a portion located at a corner of the first cutting portion 5A collide with each other due to vibration during cutting, resulting in a defect.

[0053] When the cutting tool 1 is viewed from the side of the first end 3A, the seating surface 13 may have a linear shape. In such a case, the seating surface 13 can efficiently receive the cutting load applied to the first cutting portion 5A through the back surface 37. Here, the linear shape does not have to be a strictly linear shape, and it is sufficient if it is a straight line when observed with the naked eye. The same effect can be achieved even when the entire seating surface 13 is flat.

[0054] Before the first cutting portion 5A is fastened by the first fastener 7A, the screw head 45 may abut against the second outer surface 43 only at a portion located rearward of the central axis N2 of the first fastener 7A in the rotational direction O2, as shown in Fig. 7. In such a case, when the first fastener 7A is fastened to the first cutting portion 5A, the screw head 45 presses the first cutting portion 5A rearward in the rotational direction O2, causing the first cutting portion 5A to rotate so that the seat surface 13 is pressed against the back surface 37, and the first cutting portion 5A can be stably fixed to the main body portion 3.

[0055] Here, before the first cutting portion 5A is fastened by the first fixing tool 7A, as shown in FIG. This refers to the point in time when the bottom 53 of the first fastener 7A is inserted into the screw hole 48 and the screw head 45 makes point contact with the second outer surface 43. If it is not clear when point contact occurs, the point in time when the second outer surface 43 and the screw head 45 are in contact and resistance is felt from the first fastener 7A during the process of inserting the first fastener 7A into the first cutting portion 5A may be defined as the point in time before the first cutting portion 5A is fastened by the first fastener 7A. Note that the point in time before the first fastener 7A is fastened to the first cutting portion 5A may be rephrased as the state in which the first fastener 7A is not fastened to the first cutting portion 5A.

[0056] Before being fastened to the first cutting portion 5A by the first fastener 7A, in a cross section perpendicular to the rotation axis O1, the imaginary line extending the flat second outer surface 43 is the first imaginary line L21, the imaginary line extending the flat seating surface 13 is the second imaginary line L22, the angle between the first imaginary line L21 and the second imaginary line L22 is θ1, and in a planar perspective from a direction along the rotation axis O1, the angle between the second imaginary line L22 and the central axis N2 of the first fastener 7A is θ2, and so 90° > θ1 + θ2 may be satisfied.

[0057] Specifically, in a stage before the first cutting part 5A is fastened by the first fastener 7A as shown in Fig. 7, a third imaginary line L23 passes through an intersection P1 between the second imaginary line L22 and the central axis N2 of the first fastener 7A and is perpendicular to the first imaginary line L21, and the angle between the second imaginary line L22 and the third imaginary line L23 is expediently defined as α. As shown in Fig. 8, when the first cutting part 5A is fastened by the first fastener 7A, the first cutting part 5A rotates around the central axis N1, and the angle α approaches θ2.

[0058] When the angle α is greater than the angle θ2, when the first cutting portion 5A is fastened by the first fixing tool 7A, the outer region 49 can be stably pressed against the seating surface 13 while the inner region 51 is separated from the seating surface 13. From the relationship between the angles θ1, θ2, and α shown in FIG. 7 and the fact that the sum of the interior angles of the triangle is 180°, θ1+α+90°=180° ∴α=90°-θ1 When the angle α is greater than the angle θ2, it is expressed as α>θ2. α=90°-θ1>θ2 ∴ 90°>θ1+θ2 The relationship is derived.

[0059] The cross section perpendicular to the rotation axis O1 mentioned above is a cross section including the center of any of the faces or regions (the first outer side surface 41, the second outer side surface 43, the seating surface 13, and the inner region 51), and may be a cross section of each of the faces or regions. As shown in Fig. 7, the first virtual line L21 and the second virtual line L22 may be virtual lines extending the second outer side surface 43 and the seating surface 13 in a planar perspective view from a direction along the rotation axis O1.

[0060] When the cutting tool 1 is seen through from the first end 3A side, the distance W1 between the outer region 49 and the through hole 47 is larger than the distance W2 between the inner region 51 and the through hole 47. Generally, during cutting, the outer region 49 is more likely to be subjected to a load than the inner region 51. In such a case, the cutting load applied to the first cutting portion 5A can be stably received in the outer region 49, which has a large distance from the outer region 49 to the through hole 47, i.e., is thick, while the cutting load is less likely to be applied to the inner region 51, thereby reducing the risk of deformation of the through hole 47 due to the cutting load.

[0061] The above-mentioned interval may be a interval along a straight line perpendicular to the front surface 29, or in the case where the front surface 29 is not flat and the perpendicular direction cannot be determined unequivocally, the interval may be a interval perpendicular to the first cutting edge 21 or the seat surface 13. The above-mentioned interval is not limited to the interval when the cutting tool 1 is seen through from the first end 3A side. For example, the interval may be an interval including the back surface 37 and the through hole 47, and Alternatively, it may be the interval in a cross section perpendicular to the rotation axis O1.

[0062] The comparison of the above-mentioned intervals may be limited to a comparison of the maximum or minimum values ​​of the intervals. For example, the maximum value of the interval between the outer region 49 and the through hole 47 may be compared with the maximum value of the interval between the inner region 51 and the through hole 47, or the minimum value of the interval between the outer region 49 and the through hole 47 with the minimum value of the interval between the inner region 51 and the through hole 47. Note that the above-mentioned intervals are evaluated as the intervals between each region and one of the two lines at both ends of the through hole 47 in FIG. 8 that is located rearward in the direction of rotation O2.

[0063] Before the first cutting portion 5A is fastened by the first fastener 7A, when the cutting tool 1 is seen through from the first end 3A side, the central axis N3 of the through hole 47 may be inclined with respect to the central axis N4 of the screw hole 48. The central axis N4 of the screw hole 48 may be rephrased as the central axis N2 of the first fastener 7A. The inclination mentioned above may be any angle that the central axis N3 of the through hole 47 and the central axis N4 of the screw hole 48 form with an angle greater than 0°.

[0064] 7, when viewed from the first end 3A side, the central axis N3 of the through hole 47 is inclined forward in the rotation direction O2 of the rotation axis O1 relative to the central axis N4 of the screw hole 48. When an unexpected cutting load is applied to the outer periphery of the first cutting portion 5A during cutting and the portion of the through hole 47 on the side of the second outer surface 43 moves slightly rearward in the rotation direction O2 of the rotation axis O1, the above configuration can reduce the risk of collision between the first fixing device 7A and the through hole 47.

[0065] When the cutting tool 1 is seen through from the first end 3A side, the distance W3 between the seat 13 and the through hole 47 may become smaller toward the rotation axis O1. Since the cutting load applied to the first cutting portion 5A increases with increasing distance from the rotation axis O1, when the cutting tool 1 has the above configuration, it is possible to ensure a thickness of the first cutting portion 5A corresponding to the magnitude of the cutting load.

[0066] Here, the above-mentioned interval may be an interval along a straight line perpendicular to the front surface 29, or in the case where the perpendicular cannot be uniquely determined because the front surface 29 is not flat, the interval may be an interval in a direction perpendicular to the first cutting edge 21 or the seating surface 13. In addition, the above-mentioned interval is not limited to the interval when the cutting tool 1 is seen through from the first end 3A side. For example, it may be an interval in a cross section that includes the seating surface 13 and the through hole 47 and is perpendicular to the rotation axis O1.

[0067] In addition, the fact that the distance increases toward the rotation axis O1 does not necessarily mean that the distance continues to increase, and for example, there may be a portion where the distance does not change. In addition, in FIG. 8, the distance between the seating surface 13 and the line located rearward in the rotation direction O2, out of the two lines at both ends of the through hole 47, is set as the distance W3 between the seating surface 13 and the through hole 47.

[0068] When the cutting tool 1 is seen through from the first end 3A side, the distance W4 between the seat surface 13 and the back surface 37 may increase toward the rotation axis O1. Since the cutting load on the first cutting portion 5A increases with distance from the rotation axis O1, when the cutting tool 1 has the above configuration, the thickness of the first cutting portion 5A corresponding to the magnitude of the cutting load can be ensured, and the risk of deformation of the through hole 47 due to the cutting load can be reduced.

[0069] Here, the above-mentioned interval may be an interval along a straight line perpendicular to the front surface 29, or, if the front surface 29 is not flat and the perpendicular direction cannot be determined univocally, it may be an interval in a direction perpendicular to the first cutting edge 21 or the seating surface 13. Moreover, the above-mentioned interval is not limited to the interval when the cutting tool 1 is seen through from the first end 3A side. For example, it may be an interval in a cross section including the seating surface 13 and the back surface 37 and perpendicular to the rotation axis O1.

[0070] Note that, "increasing closer to the rotation axis O1" does not necessarily mean that the above-mentioned interval continues to increase strictly. For example, there may be some points where the above-mentioned interval does not change.

[0071] The inner surface 39 and the constraining side surface 15 may abut against each other. In such a case, the first cutting portion 5A can be stably fixed to the main body portion 3. The inner surface 39 and the constraining side surface 15 may be curved as shown in FIG. 8, etc. In such a case, the first cutting portion 5A can be easily attached to the main body portion 3 while ensuring the above-mentioned stable fixation. In addition, the inner surface 39 and the constraining side surface 15 may be flat. In such a case, the first cutting portion 5A can be more stably fixed to the main body portion 3. In addition, the inner surface 39 and the constraining side surface 15 may be parallel to each other.

[0072] As shown in Fig. 11, the first cutting portion 5A may have a first portion 63 located on the first end 3A side and a second portion 65 located on the second end side of the first portion 63. The outer diameter R1 of the first portion 63 may be larger than the outer diameter R2 of the second portion 65 as shown in Figs. 12 and 13. In such a case, it becomes easier to hold the cutting edge 11 in a stable position. Here, the outer diameter may be compared with the radius from the central axis N1 when the first portion 63 or the second portion 65 is cylindrical.

[0073] Furthermore, when the first portion 63 or the second portion 65 is not cylindrical, the distances from the end points farthest from the central axis N5 of the first portion 63 and the central axis N6 of the second portion 65 may be compared, or the distances from the end points closest to the central axis N5 of the first portion 63 and the central axis N6 of the second portion 65 may be compared. Furthermore, when the outer diameters of the first portion 63 and the second portion 65 are not constant from the first end 3A side to the second end side, the outer diameters at the midpoints of each portion in the direction along the rotation axis O1 may be evaluated.

[0074] 11 is a view of the first cutting portion 5A in FIG. 9 as viewed from the A5 direction. FIG. 12 is an enlarged cross-sectional view of the cutting tool 1 taken along line XII-XII in FIG. 2. The XII-XII cross section passes through the first portion 63 and is perpendicular to the rotation axis O1. FIG. 13 is an enlarged cross-sectional view of the cutting tool 1 taken along line XIII-XIII in FIG. 2. The XIII-XIII cross section passes through the second portion 65 and is perpendicular to the rotation axis O1.

[0075] The first part 63 may have a back surface 37. The first part 63 may have a cutting edge 11. In FIG. 12, the first part 63 has the back surface 37 and the cutting insert 17. When the back surface 37 and the cutting edge 11 are in the same part, the cutting load can be stably received by the back surface 37. The second part 65 may have a second outer surface 43 and an inner surface 39. In FIG. 13, the second part 65 has the second outer surface 43 and the inner surface 39. In the above case, that is, when the cutting edge 11 and the inner surface 39 are in different parts, an excessive cutting load is applied to the first fixture 7A, and the risk of deformation of the first fixture 7A can be reduced.

[0076] The second portion 65 may have a through hole 47 as shown in Fig. 5. In this way, when the cutting edge 11 and the through hole 47 are in different parts, it is possible to reduce the risk of deformation of the through hole 47 due to an excessive cutting load being applied to the through hole 47, and also to ensure a wall thickness of the cutting portion 5.

[0077] The cutting tool 1 may have an adjustment member 67 between the main body 3 and the first cutting portion 5A. When the cutting tool 1 has the adjustment member 67, the cutting edge position of the cutting blade 11 can be adjusted by the adjustment member 67. The adjustment member 67 may have an adjustment hole 69.

[0078] The adjustment member 67 may have an adjustment hole 69. The position of the cutting edge of the cutting blade 11 can be adjusted by inserting a wrench or the like into the adjustment hole 69 and rotating it. The adjustment hole 69 may face the outer circumferential side of the rotation direction O2. In this case, a wrench or the like can be easily inserted into the adjustment hole 69. The adjustment member 67 may be covered by the main body 3 except for the portion where the adjustment hole 69 is located. In this case, the risk that the adjustment member 67 will fly off during cutting can be reduced.

[0079] When the cutting tool 1 is seen through from the side of the first end 3A, the back surface 37 may be located rearward in the rotation direction O2 of the rotation axis O1 from an intersection point P2 between an imaginary straight line L3 extending from the second outer surface 43 and the first outer surface 41. In such a case, it is possible to ensure a sufficient thickness on the outer periphery side of the first cutting portion 5A, and thus it is possible to perform stable cutting.

[0080] The screw head 45 may face the outer periphery of the rotation axis O1 as shown in FIG. 8. In this case, the first fixing device 7A can be easily inserted into the first cutting portion 5A. Also, when the cutting tool 1 is seen through from the second end side, the screw head 45 and the first portion 63 may overlap. In this case, the risk of the first fixing device 7A being damaged by chips hitting the first portion 63 during cutting processing can be reduced. For example, as shown in FIG. 10, the first cutting portion 5A may have a cutting pocket 71, and the upper portion of the cutting pocket 71 may have a curved shape that covers a part of the cutting insert 17 from above.

[0081] When the cutting tool 1 is viewed from the first end 3A side, the angle between the seating surface 13 and the first cutting edge 21 may be an angle that opens toward the outer periphery. In such a case, the distance between the cutting edge 11 of the first cutting part 5A and the seating surface 13 becomes large, and the thickness can be secured, enabling stable cutting. The first cutting edge 21 may be replaced with the front surface 29.

[0082] When the cutting tool 1 is viewed from the first end 3A side, the bearing surface 13 and the first cutting edge 21 may be parallel. In such a case, the bearing surface 13 can stably receive the cutting load related to the first cutting portion 5A through the back surface 37. Here, parallel does not strictly mean that the angle between the straight line extending the bearing surface 13 and the straight line extending the first cutting edge 21 is 0°. If the angle is -5° to 5°, the bearing surface 13 and the first cutting edge 21 may be considered to be parallel. The first cutting edge 21 may be replaced with the front surface 29.

[0083] Examples of the material of the cutting insert 17 include cemented carbide, cermet, and hard materials. Examples of the composition of 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.

[0084] Cermets are sintered composite materials that combine ceramic components with metals. Specifically, cermets are mainly composed of titanium compounds such as titanium carbide (TiC) and titanium nitride (TiN). Hard materials include, for example, cBN (Cubic Boron Nitride) and PCD (PolyCrystalline Diamond).

[0085] The surface of the cutting insert 17 may be coated with a film by using a chemical vapor deposition (CVD) method or a physical vapor deposition (PVD) method. The composition of the film may be titanium carbide (TiC), titanium nitride (TiN), titanium carbonitride (TiCN), and alumina (Al 2 O 3 ) etc.

[0086] The main body 3 may be made of a material such as steel, cast iron, or aluminum alloy. From the viewpoint of improving toughness, the main body 3 may be made of steel.

[0087] <Method of manufacturing machined products> Next, a manufacturing method of the machined product 101 according to a non-limiting embodiment will be described in detail by taking as an example a case where the cutting tool 1 according to the non-limiting embodiment described above is used. The following description will be given with reference to Figs. 14 to 16. Figs. 14 to 16 illustrate the steps of cutting a workpiece 102 as an example of a manufacturing method of the machined product 101. To facilitate visual understanding, the machined parts are hatched in Fig. 16.

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

[0089] (1) The cutting tool 1 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. 14).

[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 1 is attached, and bringing the cutting tool 1 closer to the workpiece 102 while rotating it. Note that in this step, it is sufficient that the workpiece 102 and the cutting tool 1 are relatively close to each other, and the workpiece 102 may be brought closer to the cutting tool 1.

[0091] (2) The cutting tool 1 may be brought even closer to the workpiece 102, so that the rotating cutting tool 1 comes into contact with a desired position on the surface of the workpiece 102, thereby cutting the workpiece 102 (see FIG. 15).

[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 1 may be moved away from the workpiece 102 in the Y2 direction (see FIG. 16).

[0094] In this step, similarly to the above-mentioned step (1), it is sufficient to relatively separate the cutting tool 1 from the workpiece 102, and for example, the workpiece 102 may be separated from the cutting tool 1. In addition to the milling process shown in the figure, examples of the cutting process 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 1 with different locations of the workpiece 102 while keeping the cutting tool 1 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] 1...cutting tools 3. Main body 3A...Tip (1st end) 3B...Rear end (2nd end) 5...Cutting part 5A...1st cutting section 7... Fixture 7A...1st fixture 9. Pocket 9A: First pocket 11...Cutting edge 13 Seat 15... restraint side 17. Cutting insert 19 Cartridge 21...First cutting edge 23...Second cutting edge 25 Insert hole 27 Insert Fixture 29...front surface 31...First side 33...Second side 35...First corner 36...Third cutting edge 37...Back 39...Inner surface 41...1st outer surface 43...Second outer surface 45···Screw head 47...Through hole 48···Screw hole 49...outer area 51...inner area 53...bottom 55 Outer ridge 57 Inner ridge 59...cutting hole 61... Curved section 63...Part 1 65...Second part 67...Adjusting member 69...adjustment hole 71···Cutting pocket 101...Cutting workpiece 102...Work material O1 Rotation axis O2 Rotation direction N1, N2, N3, N4, N5, N6...center axis L1, L3: Imaginary straight lines L21: First virtual line L22: Second virtual line L23: Third imaginary line S1...Area between two points W1, W2, W3, W4... spacing P1, P2...intersection R1, R2...Outer diameter Y1: Feed direction

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; a fixing device that fixes the cutting portion to the main body portion, The pocket is A seat surface facing the rotation direction of the rotation shaft; a restraining side surface located near the axis of rotation relative to the seating surface; The cutting portion is A back surface facing the seat surface; An inner surface facing the restraining side surface; a first outer surface opposite the inner surface; a second outer surface that is located closer to the rear end than the first outer surface and that is in contact with the fixing device, The back surface is an outer region located on the outer periphery side and in contact with the seat surface; an inner region connected to the inner surface and the outer region and spaced from the seating surface.

2. The second outer surface and the seat surface are flat, In a state where the cutting portion is not fastened by the fastener, In a cross section perpendicular to the rotation axis, a virtual line extending the second outer surface is a first virtual line, a virtual line extending the seat surface is a second virtual line, and an angle formed by the first virtual line and the second virtual line is a first angle, In a planar perspective view from a direction along the rotation axis, an angle formed by the second virtual line and a central axis of the fixing device is a second angle, 2. The cutting tool according to claim 1, wherein 90°>(angle of the first angle)+(angle of the second angle).

3. The cutting portion further has a through hole that opens on the second outer surface and the inner surface and into which the fixing tool is inserted, When the tip is visualized, The cutting tool according to claim 1 , wherein a distance between the outer region and the through hole is greater than a distance between the inner region and the through hole.

4. The pocket further has a screw hole that opens on the restraining side surface and faces the through hole, In a state where the cutting portion is not fastened by the fastener, The cutting tool according to claim 3 , wherein a central axis of the through hole is inclined with respect to a central axis of the screw hole.

5. The fastener has a screw head that abuts the second outer surface, In a state where the cutting portion is not fastened by the fastener, The cutting tool according to claim 3 , wherein the screw head abuts against the second outer surface only on the opposite side in the rotation direction from a central axis of the through hole.

6. The cutting tool according to claim 3, wherein, when viewed from the tip, the distance between the seat surface and the through hole becomes smaller toward the rotation axis.

7. The cutting tool according to claim 1 , wherein, when viewed from the tip, the distance between the seat surface and the back surface increases toward the rotation axis.

8. The cutting tool according to any one of claims 1 to 7, wherein the inner side surface and the constraint side surface abut against each other and have a curved shape.

9. The cutting portion is A first portion located on the tip side; a second portion located closer to the rear end than the first portion, The outer diameter of the first portion is greater than the outer diameter of the second portion, the back surface and the first outer surface are located on the first portion; The cutting tool according to any one of claims 1 to 8, wherein the second outer surface is located on the second portion.

10. The second outer surface is flat; When the tip is visualized, The cutting tool according to claim 9 , wherein the back surface is located on an opposite side in a rotation direction of the rotation shaft from an intersection point between the first outer surface and an imaginary straight line extending from the second outer surface.

11. A step of rotating the cutting tool according to any one of claims 1 to 10; contacting the cutting tool with a workpiece; and removing the cutting tool from the workpiece.

Images