Rotary tool and method for manufacturing a machined product

Abstract

To provide a rotary tool which can supply a coolant to a cutting blade without fail.SOLUTION: A rotary tool based on one aspect of the disclosure has a rod-like body extending along a rotation axis O1. The body has a first member 5, a second member 7, and a cylindrical third member 9 into which the second member is inserted. The first member 5 has a first outer surface, a frist groove, and a cutting blade. The second member 7 has a second outer surface, a second groove 29, a first passage 35, and a second passage 37. The second passage has a first outlet 39 which is open in the second groove 29. The third member 9 is located so as to enclose the first outlet 39 and the cutting blade is away from the rotary shaft farther than an inner peripheral surface of the third member 9.SELECTED DRAWING: Figure 8

Description

Technical Field

[0001] The present disclosure relates to a rotary tool and a method for manufacturing a machined product.

Background Art

[0002] As a rotary tool, for example, the rotary tool described in Patent Document 1 is known. In the rotary tool described in Patent Document 1, a coolant hole is provided in the tool body, and the coolant hole opens toward the tip side where the cutting edge of the tool is located. Thereby, during cutting, coolant can be supplied near the cutting edge.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the rotary tool described in Patent Document 1, coolant is discharged from the holder side surface toward the cutting edge. Here, since the holder rotates at high speed during cutting, the coolant may diverge, and there is a risk that the coolant cannot be reliably supplied to the cutting edge.

[0005] The present disclosure has been made in view of the above problems, and an object thereof is to provide a rotary tool capable of reliably supplying coolant to a cutting edge.

Means for Solving the Problems

[0006] A rotary tool according to one aspect of the present disclosure has a rod-shaped body extending along a rotation axis from a first end to a second end. The body has a first member located on the side of the first end, a second member located on the side of the second end rather than the first member, and a third member having a cylindrical shape into which the second member is inserted. The first member has a first outer surface, a first groove extending from the first end toward the second end on the first outer surface, and a cutting edge located behind the first groove in the rotation direction of the rotation axis with respect to the first groove and extending along the first groove. The second member has a second outer surface, a second groove extending from the side of the first end toward the second end on the second outer surface and connected to the first groove, a first flow path located inside the body and extending along the rotation axis, and a second flow path extending from the first flow path to the second groove. The second flow path has a first outlet opening into the second groove. The third member is positioned so as to surround the first outlet, and the cutting edge is farther from the rotation axis than the inner peripheral surface of the third member.

Advantages of the Invention

[0007] In the above rotary tool, coolant can be stably supplied to the cutting edge.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Mode for Carrying Out the Invention

[0009] Hereinafter, the rotary tool 1 of the embodiment in the present disclosure will be described in detail with reference to the drawings. However, each drawing referred to below shows only the main members necessary for explaining the present invention among the constituent members of the embodiment, for the sake of convenience of explanation. Therefore, the rotary tool 1 of the present invention may include any constituent members not shown in each drawing referred to in this specification. Also, the dimensions of the members in each drawing do not faithfully represent the actual dimensions of the constituent members and the dimensional ratios of each member.

[0010] The rotary tool 1 according to the embodiment in the present disclosure is a reamer. In addition to the reamer, examples of the rotary tool 1 include an end mill and a drill. Therefore, the rotary tool 1 described below may be replaced with a rotary tool 1 such as a drill and an end mill.

[0011] As shown in an example in FIG. 1, the rotary tool 1 has a rod-shaped main body 3 extending along the rotation axis O1 from the first end 3A to the second end 3B. The rod-shaped main body 3 can rotate in the rotation direction O2 about the rotation axis O1 as shown in FIG. 1 when performing cutting on the workpiece to manufacture a machined product. Note that the rotation axis O1 is the axis when the rotary tool 1 rotates, and the rotary tool 1 does not have it as a tangible object.

[0012] As shown in an example in FIG. 1, the lower end of the main body 3 is the first end 3A and the upper end is the second end 3B. Generally, the first end 3A is also called the tip 3A, and the second end 3B is also called the rear end 3B. Hereinafter, the tip 3A and the rear end 3B will be used. FIG. 2 is a plan view of the rotary tool 1 viewed from the side of the tip 3A along the rotation axis O1, and can also be referred to as a front view or a tip view. FIG. 3 is a plan view of the rotary tool 1 viewed from a direction orthogonal to the rotation axis O1, and can also be referred to as a side view.

[0013] The outer diameter of the main body 3 can be set, for example, to 10 mm to 50 mm. Also, when the length in the direction along the rotation axis O1 is L and the outer diameter is D, in the main body 3 of the embodiment, the relationship between L and D can be set, for example, to L = 5D to 30D.

[0014] In an example shown in FIG. 1, the main body 3 has a first member 5 located on the side of the tip 3A, a second member 7 located on the side of the rear end 3B rather than the first member 5, and a third member 9 having a cylindrical shape into which the second member 7 is inserted. In the main body 3 according to the embodiment, the third member 9 is a member separate from the first member 5 and the second member 7. However, for example, when the main body 3 is manufactured by a manufacturing method using a 3D printer or the like, it may be integrated with the second member 7. In an example shown in FIGS. 1 to 3, the first member 5 and the second member 7 are substantially cylindrical, and the third member 9 is substantially cylindrical.

[0015] The first member 5 has a first outer surface 11. In an example shown in FIG. 4, the first outer surface 1 1 is the side surface of the first member 5 which is substantially cylindrical in shape. Further, the main body 3 has a front end surface 13 located on the side of the front end 3A. There is no particular limitation regarding the shape of the front end surface 13. In an example shown in FIG. 4, it is substantially planar.

[0016] The first outer surface 11 may have an inclined surface 15 located on the side of the front end 3A. The inclined surface 15 may be connected to the front end surface 13 and may extend in a direction away from the rotation axis O1 as it goes from the side of the front end 3A toward the side of the rear end 3B. As shown in FIG. 4, the first outer surface 11 may have a plurality of inclined surfaces 15. There is no particular limitation regarding the shape of the inclined surface 15. For example, it may be a curved surface shape. In an example shown in FIG. 4, the inclined surface 15 is planar.

[0017] The first outer surface 11 may have a first outer peripheral surface 17. The first outer peripheral surface 17 in an example shown in FIG. 4 is located on the side of the rear end 3B rather than the inclined surface 15 and is connected to the inclined surface 15. The first outer peripheral surface 17 may have a surface configuration with a constant distance from the rotation axis O1. In this case, in a cross-section orthogonal to the rotation axis O1, the first outer peripheral surface 17 may be located on the circumcircle of the first member 5. The first outer peripheral surface 17 is composed of a plurality of surface regions located apart from each other in an example shown in FIG. 4.

[0018] The first outer peripheral surface 17 may have a surface configuration with a constant distance from the rotation axis O1 as described above, or may be inclined so as to approach the rotation axis O1 as it goes from the side of the front end 3A toward the side of the rear end 3B. When the first outer peripheral surface 17 is located on the circumcircle of the first member 5 in a cross-section orthogonal to the rotation axis O1, the first outer peripheral surface 17 becomes a curved shape. However, the first outer peripheral surface 17 is not limited to such a shape. For example, when the first outer peripheral surface 17 is composed of a plurality of surface regions located apart from each other, each surface region may be planar. That is, the first member 5 may be in the shape of a polygonal prism.

[0019] The first member 5 has a plurality of first grooves 19 extending from the tip 3A side toward the rear end 3B side on the first outer surface 11. Note that the number of the first grooves 19 is not particularly limited. In an example shown in FIG. 2, the first groove 19 opens at the tip 3A of the first member 5, and the first grooves 19 are spaced apart from each other via the first outer peripheral surface 17.

[0020] The first member 5 has a cutting edge 21 located behind the first groove 19 in the rotation direction O2 of the rotation axis O1 with respect to the first groove 19 and extending along the first groove 19. The cutting edge 21 in an example shown in FIG. 5 is located at the intersection of the first groove 19 and an inclined surface 15 adjacent to the rear of the first groove 19 in the rotation direction O2. In an example shown in FIG. 5, the first member 5 has a plurality of cutting edges 21 corresponding to the number of the plurality of first grooves 19. The cutting edge 21 may extend from the tip 3A side toward the rear end 3B side as shown in FIG. 5. Since the first member 5 has the cutting edge 21, it is generally called a cutting portion.

[0021] Since the cutting edge 21 extends along the first groove 19, when the first outer surface 11 has the first outer peripheral surface 17, the cutting edge 21 may be located not only at the intersection of the first groove 19 and the inclined surface 15 but also, for example, at the intersection of the first groove 19 and the first outer peripheral surface 17.

[0022] As shown in FIG. 5, the cutting edge 21 may have a first cutting edge 23 located on the tip 3A side and a second cutting edge 25 located on the rear end 3B side of the first cutting edge 23. In this case, the first cutting edge 23 is located at the intersection of the first groove 19 and the inclined surface 15. The second cutting edge 25 is located at the intersection of the first groove 19 and the first outer peripheral surface 17. The second cutting edge 25 may be connected to the first cutting edge 23 or may be separated from the first cutting edge 23. The first cutting edge 23 may extend in a direction away from the rotation axis O1 as it goes from the tip 3A side toward the rear end 3B side.

[0023] The second cutting edge 25 may extend in a direction approaching the rotation axis O1 as it goes from the tip 3A side toward the rear end 3B side. The second cutting edge 25 may be located along the first outer peripheral surface 17. The end portion on the rear end 3B side of the first cutting edge 23 and the end portion on the tip 3A side of the second cutting edge 25 may be connected.

[0024] The second member 7 has a second outer surface 27. In an example shown in FIG. 4, the second outer surface 27 is the side surface of the second member 7 having a substantially cylindrical shape. The second outer surface 27 may have a second outer peripheral surface 28. The second outer peripheral surface 28 may have a surface configuration with a constant distance from the rotation axis O1. In this case, in a cross section orthogonal to the rotation axis O1, the second outer peripheral surface 28 may be located on the circumscribed circle of the second member 7. The second outer peripheral surface 28 is composed of a plurality of surface regions that are spaced apart from each other in an example shown in FIG. 4.

[0025] In an example shown in FIG. 4, the second member 7 has a plurality of second grooves 29 extending from the tip 3A side toward the rear end 3B side on the second outer surface 27. Note that the number of the second grooves 29 is not particularly limited. In an example shown in FIG. 4, the second groove 29 is connected to the first groove 19 on the tip 3A side of the second member 7. The plurality of second grooves 29 may be spaced apart from each other via the second outer peripheral surface 28.

[0026] In an example shown in FIG. 1, the second member 7 has a shank portion 31 located on the rear end 3B side of the second groove 29. The shank portion 31 is a portion that is gripped by a rotating spindle or the like in a machine tool and may be designed according to the shape of the spindle. Examples of the shape of the shank portion 31 include a straight shank, a long shank, a long neck, and a taper shank.

[0027] The first member 5 and the second member 7 may be made of separate members. In this case, as shown in FIG. 4, a configuration in which the first member 5 is attached to the second member 7 by inserting a fixture 33 from the tip 3A side of the main body 3 may be adopted. Also, as shown in FIG. 4, the fixture 33 may constitute the tip surface 13 of the main body 3.

[0028] As shown in FIGS. 6 and 7, in a cross section orthogonal to the rotation axis O1, the maximum value of the diameter D1 of the portion of the first member 5 having the cutting edge 21 may be larger than the maximum value of the diameter D2 of the portion of the second member 7 having the second groove 29. In such a case, since the diameter of the portion of the second member 7 located on the tip 3A side is smaller than the machining diameter of the tool, it becomes possible to insert the main body 3 deeper into the machining hole during cutting, and the machinable range in the direction along the rotation axis O1 becomes wider.

[0029] Note that FIG. 6 is a cross-sectional view of the main body 3 cut along line VI-VI in FIG. 5. The VI-VI cross section passes through the contact point P of the first cutting edge 23 and the second cutting edge 25 and is a cross section orthogonal to the rotation axis O1. FIG. 7 is a cross-sectional view of the main body 3 cut along line VII-VII in FIG. 5. The VII-VII cross section includes the second groove 29 and is a cross section orthogonal to the rotation axis O1.

[0030] The second member 7 has a first flow path 35 extending along the rotation axis O1. As shown in FIG. 8, the first flow path 35 is located inside the main body 3 and extends from the tip 3A side to the rear end 3B side. Also, in an example shown in FIG. 8, the first flow path 35 passes through the center of the main body 3. There is no particular limitation on the shape of the first flow path 35, and as shown in FIG. 8, it may be linear. Note that FIG. 8 is a cross-sectional view of the main body 3 cut along line VIII-VIII in FIG. 2. The VIII-VIII cross section passes through the center of the third member 9 and is a cross section parallel to the rotation axis O1.

[0031] The second member 7 has one or a plurality of second flow paths 37 extending from the first flow path 35 to the second groove 29. As shown in FIG. 8, the second member 7 may have a plurality of second flow paths 37, and in a cross section including the rotation axis O1 and the second flow paths 37, each second flow path 37 may extend from the first flow path 35 toward the second groove 29.

[0032] In an example shown in FIG. 8, the second flow path 37 extends toward the tip 3A side and the outer peripheral side. The shape of the second flow path 37 is not particularly limited, and as shown in FIG. 8, it may be linear. Further, when the main body 3 is viewed through the tip, the plurality of second flow paths 37 may extend so as to radially spread from the center of the main body 3.

[0033] The second flow path 37 has a first outlet 39 that opens into the second groove 29. The first outlet 39 is provided to discharge the coolant that has passed through the first flow path 35 and the second flow path 37 into the second groove 29. As shown in FIG. 8, the first outlet 39 is located on the tip 3A side and the outer peripheral side of the second flow path 37. The first outlet 39 may open on the rear end 3B side of the second groove 29 as shown in FIG. 8, or may open on the tip 3A side of the second groove 29.

[0034] The third member 9 has an inner peripheral surface 41 and an outer peripheral surface 43. The diameters of the inner peripheral surface 41 and the outer peripheral surface 43 may be constant. Since the second member 7 is inserted into the third member 9, as shown in FIG. 9, the diameter D3 of the portion of the inner peripheral surface 41 located on the rear end 3B side of the third member 9 is equal to or larger than the diameter of the portion of the second member 7 located on the tip 3A side.

[0035] As shown in FIG. 11, the third member 9 is positioned so as to surround the first outlet 39. Note that FIG. 11 is an enlarged view of the main body 3 shown in FIG. 3 and is a view through the second member 7. Here, the third member 9 being positioned so as to surround the first outlet 39 means that when the main body 3 is viewed from the side, the entire first outlet 39 overlaps with the third member 9 and thus the first outlet 39 cannot be visually observed. In the side view, if the above state cannot be determined, it may be evaluated in a cross section that includes the first outlet 39 and is perpendicular to the rotation axis O1. In this cross section, when the third member 9 is located on the virtual straight line connecting the rotation axis O1 and the first outlet 39, it may be determined that the third member 9 is positioned so as to surround the first outlet 39.

[0036] The cutting edge 21 is farther from the rotation axis O1 than the inner peripheral surface 41 of the third member 9. Specifically, in a cross-section orthogonal to the rotation axis O1 shown in FIG. 6 and a front view from the direction along the rotation O1 shown in FIG. 10, the distance W1 from the rotation axis O1 to the cutting edge 21 is greater than the distance W2 from the rotation axis O1 to the inner peripheral surface 41.

[0037] Here, the maximum value of the distance from the rotation axis O1 to the cutting edge 21 may be used as the distance from the rotation axis O1 to the cutting edge 21, and the distance from the rotation axis O1 to the portion on the tip 3A side of the inner peripheral surface 41 may be used as the distance from the rotation axis O1 to the inner peripheral surface 41. Note that FIG. 10 is a view of the third member 9 from the tip 3A side along the rotation axis O1. Further, as shown in FIGS. 9 and 10, the central axis C1 of the third member 9 may be replaced with the rotation axis O1 of the main body 3.

[0038] In an example shown in FIGS. 6 and 10, the distance W1 from the rotation axis O1 to the contact point P of the first cutting edge 23 and the second cutting edge 25 is greater than the distance W2 from the rotation axis O1 to the portion on the tip 3A side of the inner peripheral surface 41. Note that when the diameter of the inner peripheral surface 41 is not constant or the cross-section of the inner peripheral surface 41 is not circular, the above intervals may be compared on an imaginary straight line passing through the rotation axis O1 and the first outlet 39 in a cross-section orthogonal to the rotation axis O1 and including the first outlet 39.

[0039] Generally, from the viewpoint of ensuring the wall thickness of the tip 3A portion where the cutting load is likely to be applied in the tool body, it is desirable to provide the flow path passing through the inside of the main body 3 and the outlet through which the coolant is discharged on the rear end 3B side of the main body 3. In such a case, while the wall thickness on the tip 3A side is ensured the distance between the first outlet 39 and the cutting edge 21 becomes large.

[0040] In the rotary tool 1 according to the present embodiment, during cutting, the coolant is discharged from the first outlet 39 toward the tip 3A of the main body 3 through the first flow path 35 and the second flow path 37. Here, since the third member 9 surrounds the first outlet 39, even when the distance between the first outlet 39 and the cutting edge 21 is large, the coolant discharged from the first outlet 39 collides with the inner peripheral surface 41 of the third member 9 and easily flows toward the tip 3A along the second groove 29 and the first groove 19. As a result, the coolant can be stably supplied to the cutting edge 21 located on the tip 3A side, and the durability of the cutting edge 21 is increased.

[0041] Also, during cutting, the tool body is rotating at high speed. Therefore, when the first outlet 39 simply opens to the outer surface of the main body 3 as in the case without the third member 9, the centrifugal force applied to the coolant also affects, and the coolant is likely to scatter in the direction away from the rotation axis O1. As a result, there is a possibility that the coolant cannot be properly supplied to the cutting edge 21 located on the tip 3A side.

[0042] However, in the rotary tool 1 according to the present embodiment, the cutting edge 21 is farther from the rotation axis O1 than the inner peripheral surface 41 of the third member 9. Therefore, even when the centrifugal force in the direction away from the main body 3 is applied to the coolant, the coolant can be supplied to the cutting edge 21 more stably.

[0043] The cutting edge 21 may be farther from the rotation axis O1 than the outer peripheral surface 43 of the third member 9. Specifically, in the cross section orthogonal to the rotation axis O1 shown in FIG. 6 and the front view from the direction along the rotation axis O1 shown in FIG. 10, the distance W1 from the rotation axis O1 to the cutting edge 21 may be larger than the distance W3 from the rotation axis O1 to the outer peripheral surface 43. Here, the maximum value of the distance from the rotation axis O1 to the cutting edge 21 may be used as the distance from the rotation axis O1 to the cutting edge 21, and the distance from the rotation axis O1 to the portion on the tip 3A side of the outer peripheral surface 43 may be used as the distance from the rotation axis O1 to the outer peripheral surface 43.

[0044] In one example shown in FIGS. 6 and 10, the distance W1 from the rotation axis O1 to the contact point P between the first cutting edge 23 and the second cutting edge 25 is greater than the distance W3 from the rotation axis O1 to the portion on the tip 3A side of the outer peripheral surface 43. Note that when the diameter of the outer peripheral surface 43 is not constant or the cross-sectional view of the outer peripheral surface 43 is not circular, the comparison of the above intervals may be made in a cross-section including the tip 3A side of the third member 9 and orthogonal to the rotation axis O1.

[0045] In such a case, since the machining diameter of the tool is larger than the outer diameter of the third member 9, the main body 3 can be inserted into the machining hole up to the position of the third member 9 during cutting, and the machining range in the direction along the rotation axis O1 becomes wider.

[0046] As shown in FIG. 3, the third member 9 may be located on the rear end 3B side with respect to the first member 5. Also, a part of the tip 3A side of the second groove 29 may open to the outer peripheral side. That a part of the tip 3A side of the second groove 29 opens to the outer peripheral side means a state where the second groove 29 can be visually observed when the main body 3 is viewed from the side. Note that when the above state cannot be determined in a side view, the evaluation may be made in a cross-section including the tip 3A side portion of the second groove 29 and orthogonal to the rotation axis O1. In this cross-section, when the third member 9 is not located on the virtual straight line connecting the rotation axis O1 and the first outlet 39, it may be determined that a part of the tip 3A side of the second groove 29 opens to the outer peripheral side.

[0047] In the above case, it is possible to avoid the risk that the chips generated during cutting enter between the second member 7 and the third member 9 and damage the main body 3.

[0048] The second flow path 37 may extend in a direction toward the tip 3A as it moves away from the first flow path 35. Also, the central axis C2 of the second flow path 37 may intersect the third member 9. Specifically, as shown in FIG. 8, it is sufficient that a virtual extension line N obtained by extending the central axis C2 of the second flow path 37 intersects the inner peripheral surface 41 of the third member 9. In such a case, the coolant discharged from the first outlet 39 collides with the third inner peripheral surface 41, changing the direction of flow of the coolant, and the coolant can flow smoothly in the direction of the tip 3A and in a direction approaching the rotation axis O1. Therefore, even when centrifugal force is applied to the coolant, the coolant can be supplied to the cutting blade 21 more stably.

[0049] As shown in FIG. 5, the first groove 19 and the second groove 29 may each have a shape that extends forward in the rotation direction O2 as they approach the rear end 3B. The first groove 19 and the second groove 29 may each have a shape that is twisted in a direction toward the rear in the rotation direction O2 as they approach the tip 3A. During cutting, the discharged coolant flows in a direction toward the rear in the rotation direction O2 relative to the rotating tool body. Therefore, when the tool has the above configuration, the direction in which the first groove 19 and the second groove 29 extend coincides with the direction in which the coolant flows, and the coolant can be efficiently supplied to the cutting blade 21 located along the first groove 19.

[0050] As shown in FIGS. 6 and 7, in the circumferential direction of the rotation axis O1, the width W4 of the first groove 19 may be larger than the width W5 of the second groove 29. In such a case, since the second groove 29 is smaller than the first groove 19, chips generated during cutting are less likely to flow from the first groove 19 to the second groove 29. Also, the coolant can flow smoothly from the second groove 29 to the first groove 19. When the widths of the first groove 19 and the second groove 29 are not constant, the above widths may be evaluated in a cross section that includes the center of each groove and is perpendicular to the rotation axis O1.

[0051] In an example shown in FIG. 8, the third member 9 is attached to the second member 7. Specifically, as shown in FIG. 8, the portion of the second member 7 located between the second groove 29 and the shank portion 31 is connected to the portion of the third member 9 located on the side of the rear end 3B, thereby achieving the attachment.

[0052] The second outer surface 27 may have a first screw groove 45 located on the side of the rear end 3B with respect to the second groove 29. The third member 9 has a second screw groove 47 that is screwed into the first screw groove 45. Specifically, as shown in FIG. 8, the main body 3 has a first screw groove 45 in the portion located between the second groove 29 and the shank portion 31 of the second member 7, and a second screw groove 47 in the portion located on the side of the rear end 3B of the third member 9. In such a case, the position of the third member 9 in the direction along the rotation axis O1 can be adjusted according to the tightening degree of the screw, and the outflow direction of the coolant can be adjusted.

[0053] Examples of the material of the first member 5 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. WC-TiC-Co is obtained by adding titanium carbide (TiC) to WC-Co. WC-TiC-TaC-Co is obtained by adding tantalum carbide (TaC) to WC-TiC-Co.

[0054] Cermet is a sintered composite material in which a ceramic component is combined with a metal. Specifically, examples of cermet include those mainly composed of titanium compounds such as titanium carbide (TiC) and titanium nitride (TiN). Examples of hard materials include, for example, cBN (Cubic Boron Nitride), PCD (PolyCrystalline Diamond), etc.

[0055] Examples of the material of the second member 7 include steel and cemented carbide. Examples of the composition of the cemented carbide include WC-Co, WC-TiC-Co, and WC-TiC-TaC-Co. WC-Co is produced by adding cobalt (Co) powder to tungsten carbide (WC) and sintering. WC-TiC-Co is obtained by adding titanium carbide (TiC) to WC-Co. WC-TiC-TaC-Co is obtained by adding tantalum carbide (TaC) to WC-TiC-Co. From the viewpoint of enhancing toughness, steel may be used as the material of the second member 7.

[0056] As the material of the third member 9, steel, cast iron, aluminum alloy, etc. can be used.

[0057] The surface of the first member 5 may be coated with a film using a chemical vapor deposition (CVD) method or a physical vapor deposition (PVD) method. Examples of the composition of the film include titanium carbide (TiC), titanium nitride (TiN), titanium carbonitride (TiCN), or alumina (Al2O3).

[0058] <Method for manufacturing a machined product> Next, an embodiment of the method for manufacturing a machined product according to the present invention will be described with reference to FIGS. 12 to 14. FIGS. 12 to 14 are cross-sectional views of the workpiece 100 including the center of the machining hole, but the rotary tool 1 is shown in a side view state instead of a cross-sectional view for convenience of explanation.

[0059] The method for manufacturing a machined product according to the embodiment of the present invention includes a step of rotating the above-described rotary tool 1 about the rotation axis O1, a step of bringing the cutting edge 21 of the rotating rotary tool 1 into contact with the workpiece 100, and a step of separating the workpiece 100 from the rotary tool 1.

[0060] Specifically, it includes the following steps (i) to (iii).

[0061] (i) As shown in FIG. 12, a step of rotating the rotary tool 1 in the rotation direction O2 about the rotation axis O1 and moving the rotary tool 1 in the Y1 direction to approach the workpiece 100.

[0062] In this process, the workpiece 100 and the rotary tool 1 may be relatively brought closer to each other. For example, the workpiece 100 may be brought closer to the rotary tool 1.

[0063] (ii) Next, as shown in FIG. 13, by further bringing the rotary tool 1 closer to the workpiece 100, the cutting edge 21 of the rotating rotary tool 1 is brought into contact with the inner wall of the machining hole of the workpiece 100.

[0064] This can smooth the inner wall of the machining hole. For example, if burrs remain in the machining hole of the workpiece 100, these burrs can be removed. In this process, by using a rotary tool 1 having a diameter larger than the machining hole of the workpiece 100, cutting can be performed to widen the diameter of the machining hole.

[0065] (iii) As shown in FIG. 14, the step of moving the rotary tool 1 in the Y2 direction to separate the rotary tool 1 from the workpiece 100.

[0066] By going through the above steps, it is possible to smooth the inner wall of the machining hole, that is, to exhibit excellent hole machinability, and at the same time, it is possible to have an excellent tool life of the rotary tool 1. Therefore, it becomes possible to stably cut the inner wall of the machining hole of the workpiece 100 over a long period.

[0067] When performing the cutting process of the workpiece 100 as described above a plurality of times, for example, when smoothing the inner walls of a plurality of machining holes, while maintaining the state of rotating the rotary tool 1, the cutting edge 21 of the rotary tool 1 is brought into contact with the inner walls of the machining holes located at different positions of the workpiece 100, and this process may be repeated.

[0068] Typical examples of the material of the workpiece 100 include carbon steel, alloy steel, stainless steel, cast iron, or non-ferrous metals.

[0069] As described above, several embodiments of the present invention have been illustrated. However, the present invention is not limited to the above-described embodiments, and it goes without saying that any modifications can be made without departing from the gist of the present invention.

Explanation of Reference Numerals

[0070] 1 ··· Rotating tool 3 ··· Main body 3A ··· First end (tip) 3B ··· Second end (rear end) 5 ··· First member 7 ··· Second member 9 ··· Third member 11 ··· First outer surface 13 ··· Tip surface 15 ··· Inclined surface 17 ··· First outer peripheral surface 19 ··· First groove 21 ··· Cutting edge 23 ··· First cutting edge 25 ··· Second cutting edge 27 ··· Second outer surface 28 ··· Second outer peripheral surface 29 ··· Second groove 31 ··· Shank portion 33 ··· Fixture 35 ··· First flow path 37 ··· Second flow path 39 ··· First flow outlet 41 ··· Inner peripheral surface 43 ··· Outer peripheral surface 45 ··· First thread groove 47 ··· Second thread groove 100 ··· Workpiece O1 ··· Rotation axis O2 ··· Rotation direction L ··· Length of the main body D ··· Outer diameter of the main body D1, D2, D3 ··· Diameters P ··· Contact point W1, W2, W3, W4, W5 ··· Spacings (widths) C1, C2 ··· Central axes N ··· Virtual extension line Y1, Y2 ··· Moving directions

Claims

1. It has a rod-shaped body extending along a rotation axis from a first end toward a second end, The body is, A first member located on the side of the first end, A second member located on the side of the second end rather than the first member, It has a cylindrical shape and a third member into which the second member is inserted, The first member is, A first outer surface, A first groove extending from the first end toward the second end on the first outer surface, A cutting edge located behind the first groove in the rotation direction of the rotation axis with respect to the first groove and extending along the first groove, The second member is, A second outer surface, A second groove extending from the side of the first end toward the second end on the second outer surface and connected to the first groove, A first flow path located inside the body and extending along the rotation axis, A second flow path extending from the first flow path to the second groove, The second flow path has a first outlet opening into the second groove, The third member is positioned to surround the first outlet, The cutting edge is farther from the rotation axis than the inner peripheral surface of the third member, The first flow path extends to the end on the side of the first end of the second member, a rotary tool.

2. The cutting edge is farther from the rotation axis than the outer peripheral surface of the third member, the rotary tool according to claim 1.

3. The third member is located on the side of the second end rather than the first member, A part on the side of the first end in the second groove is open to the outer peripheral side, the rotary tool according to claim 1 or 2.

4. The second flow path is linear and extends in a direction toward the first end as it moves away from the first flow path, The central axis of the second flow path intersects the third member, the rotary tool according to any one of claims 1 to 3.

5. The first groove and the second groove are each shaped to go forward in the rotation direction as they go toward the second end, the rotary tool according to any one of claims 1 to 4.

6. In the circumferential direction of the rotation axis, the width of the first groove is larger than the width of the second groove, the rotary tool according to any one of claims 1 to 5.

7. A step of rotating the rotary tool according to any one of claims 1 to 6, A step of bringing the rotating rotary tool into contact with a workpiece to be machined, A step of separating the rotary tool from the workpiece to be machined, a method for manufacturing a machined product.

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