End mill

Abstract

We provide a technology that can smoothly finish the cut surface. [Solution] The end mill may include a first outer peripheral cutting edge that cuts the workpiece when it rotates in a first rotational direction, and a second outer peripheral cutting edge that cuts the workpiece when it rotates in a second rotational direction opposite to the first rotational direction. The first and second outer peripheral cutting edges may be positioned at equidistant locations from the central axis of the end mill.

Description

Technical Field

[0001] The technology disclosed in the present specification relates to an end mill.

Background Art

[0002] Patent Document 1 discloses an end mill. The end mill of Patent Document 1 includes a plurality of peripheral cutting edges.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the end mill of Patent Document 1, when cutting a cutting target by rotating in a predetermined direction, problems such as burrs occurring at the cut portion may arise. The present specification provides a technology capable of finishing a cut portion smoothly.

Means for Solving the Problems

[0005] A first aspect of the present technology relates to an end mill for cutting a cutting target. The end mill may include a first peripheral cutting edge that cuts the cutting target when rotating in a first rotational direction, and a second peripheral cutting edge that cuts the cutting target when rotating in a second rotational direction opposite to the first rotational direction. The first peripheral cutting edge and the second peripheral cutting edge may be provided at positions equidistant from the central axis of the end mill.

[0006] According to this configuration, the cutting target can be cut by the first peripheral cutting edge and the second peripheral cutting edge, and the cut portion of the cutting target can be finished smoothly. For example, by cutting the portion cut by the first peripheral cutting edge with the second peripheral cutting edge, the cut portion can be finished smoothly.

[0007] In a second embodiment, in the first embodiment, the first outer peripheral blade and the second outer peripheral blade may be straight blades without a helix angle.

[0008] This configuration makes it less likely for the workpiece to distort during cutting. As a result, the cut surface of the workpiece can be finished smoothly.

[0009] In a third embodiment, in the first embodiment, the first outer peripheral blade and the second outer peripheral blade may be helical blades having a helix angle.

[0010] This configuration allows for smooth cutting of the workpiece and a smooth finish on the cut portion of the workpiece.

[0011] In a fourth embodiment, in any one of the first to third embodiments, the end mill may further include an outer surface that extends in an arc shape from the first outer cutting edge to the second outer cutting edge.

[0012] This configuration allows the end mill to rotate smoothly, resulting in a smooth finish on the cut surface of the workpiece.

[0013] In the fifth embodiment, in any one of the first to fourth embodiments, the end mill may further include: a first outer rake face for scooping up cutting chips generated when the first outer rake blade cuts the workpiece; a second outer rake face for scooping up cutting chips generated when the second outer rake blade cuts the workpiece; and a convex portion projecting toward the central axis of the end mill between the first outer rake face and the second outer rake face.

[0014] With this configuration, the presence of a protrusion allows for the smooth discharge of cutting chips generated when the first and second outer blades cut the workpiece.

[0015] In the sixth embodiment, in any one of the first to fifth embodiments, the end mill may further include a first bottom cutting edge that cuts the workpiece in the axial direction of the end mill when it rotates in the first rotational direction, and a second bottom cutting edge that cuts the workpiece in the axial direction of the end mill when it rotates in the second rotational direction.

[0016] This configuration allows the workpiece to be cut along the axial direction of the end mill.

[0017] In the seventh embodiment, in any one of the first to fifth embodiments described above, the object to be cut may be made from a material containing at least one of synthetic rubber, natural rubber, and synthetic resin.

[0018] When the workpiece is made from a material containing at least one of synthetic rubber, natural rubber, and synthetic resin, burrs tend to form on the cut surface. However, with the above-described end mill, even when the workpiece is made from the above-described material, the cut surface can be finished smoothly. Therefore, it is particularly effective when the workpiece is made from the above-described material.

[0019] In the eighth embodiment, the object to be cut may be made from urethane in the seventh embodiment described above.

[0020] When the material to be cut is made of urethane, burrs tend to form on the cut surface. However, with the end mill described above, even when the material to be cut is urethane, the cut surface can be finished smoothly.

[0021] A ninth aspect of this technology relates to a cutting method for cutting a workpiece using an end mill according to any of the first to eighth aspects described above. The cutting method may include a first step of cutting the workpiece with the end mill rotated in the first rotational direction, and a second step of cutting the workpiece in the portion cut by the end mill in the first step with the end mill rotated in the second rotational direction.

[0022] According to this configuration, by cutting the portion cut by the first peripheral cutting edge in the first step with the second peripheral cutting edge in the second step, the cut portion can be finished smoothly.

[0023] In a tenth aspect, in the aforementioned ninth aspect, in the first step, the cutting target may be cut by feeding the end mill in a first feed direction. In the second step, the cutting target may be cut by feeding the end mill in a second feed direction opposite to the first feed direction.

[0024] According to this configuration, by cutting the portion cut in the first step in the opposite direction in the second step, the cut portion can be finished smoothly.

[0025] In an eleventh aspect, in the aforementioned ninth or tenth aspect, in the second step, the end portion of the cutting target cut by the end mill in the first step may be cut again.

[0026] Burrs are likely to occur at the end portion of the cutting target, but according to the above cutting method, by cutting the end portion of the cutting target that was cut by the first peripheral cutting edge in the first step with the second peripheral cutting edge in the second step, the cut portion at the end portion of the cutting target can be finished smoothly. Brief Description of the Drawings

[0027] [Figure 1] A side view of the end mill of the embodiment. [Figure 2] A II-II cross-sectional view of Figure 1. [Figure 3] A view of the end mill of the embodiment as viewed in the axial direction from the tip end side. [Figure 4] Figure (1) for explaining the cutting method using the end mill of the embodiment. [Figure 5] Figure (2) for explaining the cutting method using the end mill of the embodiment. Modes for Carrying Out the Invention

[0028] The end mill 2 of the embodiment will be described with reference to the drawings. As shown in Figure 1, the end mill 2 of the embodiment comprises a body portion 4 and a shank portion 6. The end mill 2 is a tool that cuts a workpiece by rotating around a central axis C as the center of rotation. The end mill 2 is made from, for example, cemented carbide, but the material of the end mill 2 is not particularly limited. The workpiece that the end mill 2 cuts is also not particularly limited, but examples include products made from materials containing at least one of synthetic rubber, natural rubber, and synthetic resin. Examples of products made from such materials include products made from urethane. Other examples include products made from nitrile rubber, silicone, plastic, etc.

[0029] The body portion 4 and shank portion 6 of the end mill 2 are aligned in the axial direction of the end mill 2. The body portion 4 is located at the axial tip end of the end mill 2, and the shank portion 6 is located at the axial base end end of the end mill 2. The shank portion 6 is attached to a machine that rotates the end mill 2.

[0030] As shown in Figures 1 and 2, the body portion 4 of the end mill 2 comprises a first outer cutting edge 10, a second outer cutting edge 20, and an arc-shaped outer surface 8. The body portion 4 also comprises a first outer cutting edge rake face 12, a first outer cutting edge relief face 14, a second outer cutting edge rake face 22, and a second outer cutting edge relief face 24.

[0031] The first outer cutting edge 10 is provided on the side of the body portion 4 and extends along the axial direction of the end mill 2. The first outer cutting edge 10 has a straight cutting edge configuration without a helix angle. The helix angle of the first outer cutting edge 10 is 0 degrees. The cutting edge angle of the first outer cutting edge 10 can be set as appropriate. The first outer cutting edge 10 cuts the workpiece when the end mill 2 rotates in the first rotational direction R1 (for example, clockwise rotation). The cutting edge of the first outer cutting edge 10 faces forward in the first rotational direction R1. The first outer cutting edge 10 cuts the workpiece when the end mill 2 advances in a direction perpendicular to the axial direction of the end mill 2.

[0032] The second outer cutting edge 20 is provided on the side of the body portion 4 and extends linearly along the axial direction of the end mill 2. The second outer cutting edge 20 has a straight cutting edge configuration without a helix angle. The helix angle of the second outer cutting edge 20 is 0 degrees. The cutting edge angle of the second outer cutting edge 20 can be set as appropriate. The cutting edge angle of the second outer cutting edge 20 is the same angle as the cutting edge angle of the first outer cutting edge 10. In a modified example, the cutting edge angle of the second outer cutting edge 20 may be a different angle from the cutting edge angle of the first outer cutting edge 10. The second outer cutting edge 20 cuts the workpiece when the end mill 2 rotates in the second rotation direction R2, which is opposite to the first rotation direction R1 (for example, rotating counterclockwise). The cutting edge of the second outer cutting edge 20 faces forward in the second rotation direction R2. The second outer cutting edge 20 cuts the workpiece when the end mill 2 advances in a direction perpendicular to the axial direction of the end mill 2.

[0033] The first outer cutting edge 10 and the second outer cutting edge 20 are located on the same circle X centered on the central axis C of the end mill 2. The first outer cutting edge 10 and the second outer cutting edge 20 are positioned at equidistant locations from the central axis C of the end mill 2. The distance L1 from the central axis C of the end mill 2 to the cutting edge of the first outer cutting edge 10 and the distance L2 from the central axis C of the end mill 2 to the cutting edge of the second outer cutting edge 20 are the same. The angle θ between the cutting edge of the first outer cutting edge 10, the central axis C of the end mill 2, and the cutting edge of the second outer cutting edge 20 is, for example, less than 180 degrees.

[0034] The first outer rake face 12 is provided along the first outer periphery blade 10. The first outer periphery blade rake face 12 extends along the axial direction of the end mill 2 together with the first outer periphery blade 10. The first outer periphery blade rake face 12 is the surface that scoops up the cutting chips generated when the first outer periphery blade 10 cuts the workpiece. The first outer periphery blade rake face 12 faces forward in the first rotational direction R1 of the end mill 2. The first outer periphery blade rake face 12 extends radially inward from the first outer periphery blade 10 on the forward side of the first rotational direction R1. The first outer periphery blade rake face 12 is located closer to the central axis C of the end mill 2 than the outer periphery surface 8. The rake angle of the first outer periphery blade rake face 12 can be set as appropriate.

[0035] The second outer circumferential cutting edge rake face 22 is provided along the second outer circumferential cutting edge 20. The second outer circumferential cutting edge rake face 22 extends along the axial direction of the end mill 2 together with the second outer circumferential cutting edge 20. The second outer circumferential cutting edge rake face 22 is the surface that scoops up the chips generated when the second outer circumferential cutting edge 20 cuts the workpiece. The second outer circumferential cutting edge rake face 22 faces forward in the second rotational direction R2 of the end mill 2. The second outer circumferential cutting edge rake face 22 extends radially inward from the second outer circumferential cutting edge 20 on the forward side of the second rotational direction R2. The second outer circumferential cutting edge rake face 22 is located closer to the central axis C of the end mill 2 than the outer circumferential surface 8. The rake angle of the second outer circumferential cutting edge rake face 22 can be set as appropriate.

[0036] A protrusion 50 is provided between the first outer circumferential cutting edge rake face 12 and the second outer circumferential cutting edge rake face 22. The protrusion 50 is located on the side of the central axis C of the end mill 2 that is closer to the outer circumferential surface 8. The protrusion 50 projects toward the central axis C of the end mill 2. The tip 50a of the protrusion 50 is located on the opposite side of the central axis C of the end mill 2 from the imaginary line Y connecting the cutting edge of the first outer circumferential cutting edge 10 and the cutting edge of the second outer circumferential cutting edge 20.

[0037] The first outer peripheral blade rake face 12 comprises a first portion 12a and a second portion 12b. The first portion 12a extends from the first outer peripheral blade 10 to the convex portion 50. The second portion 12b extends from the end of the first portion 12a to the tip 50a of the convex portion 50. The second portion 12b of the first outer peripheral blade rake face 12 constitutes one of the slopes of the convex portion 50.

[0038] The second outer circumferential cutting edge rake face 22 comprises a first portion 22a and a second portion 22b. The first portion 22a extends from the second outer circumferential cutting edge 20 to the convex portion 50. The second portion 22b extends from the end of the first portion 22a to the tip 50a of the convex portion 50. The second portion 22b of the second outer circumferential cutting edge rake face 22 constitutes the other slope of the convex portion 50.

[0039] The first outer peripheral relief surface 14 is provided along the first outer peripheral cutting edge 10. The first outer peripheral relief surface 14 extends along the axial direction of the end mill 2 together with the first outer peripheral cutting edge 10. The first outer peripheral cutting edge 10 is formed at the ridge where the first outer peripheral relief surface 14 and the first outer peripheral cutting edge rake face 12 intersect. The first outer peripheral relief surface 14 is a surface for avoiding friction between the first outer peripheral cutting edge 10 and the workpiece. The first outer peripheral relief surface 14 faces the rear side in the first rotational direction R1 of the end mill 2. The first outer peripheral relief surface 14 extends from the first outer peripheral cutting edge 10 to the rear side in the first rotational direction R1. The relief angle of the first outer peripheral relief surface 14 can be set as appropriate.

[0040] The second outer edge relief surface 24 is provided along the second outer edge 20. The second outer edge relief surface 24 extends along the axial direction of the end mill 2 together with the second outer edge 20. The second outer edge 20 is formed at the ridge where the second outer edge relief surface 24 and the second outer edge rake face 22 intersect. The second outer edge relief surface 24 is a surface that avoids friction between the second outer edge 20 and the workpiece. The second outer edge relief surface 24 faces the rear side in the second rotation direction R2 of the end mill 2. The second outer edge relief surface 24 extends from the second outer edge 20 to the rear side in the second rotation direction R2. The relief angle of the second outer edge relief surface 24 can be set as appropriate.

[0041] The first outer edge relief surface 14 and the second outer edge relief surface 24 are located on the arc-shaped outer surface 8 of the body portion 4. The arc-shaped outer surface 8 extends from the cutting edge of the first outer edge 10 to the cutting edge of the second outer edge 20. If we consider a virtual circle X with a radius equal to the distance from the central axis C of the end mill 2 to the cutting edge of the first outer edge 10 (or the cutting edge of the second outer edge 20), the outer surface 8 is located inside the virtual circle X (towards the central axis C of the end mill 2). Note that the cutting edges of the first outer edge 10 and the cutting edges of the second outer edge 20 are located on the virtual circle X.

[0042] As shown in Figures 1 and 3, the body portion 4 of the end mill 2 further comprises a first bottom cutting edge 30, a second bottom cutting edge 40, a first bottom cutting edge rake face 32, a second bottom cutting edge rake face 42, a first bottom cutting edge relief face 34, and a second bottom cutting edge relief face 44.

[0043] The first bottom cutting edge 30 is provided at the axial tip of the body portion 4. When the end mill 2 is viewed axially from the tip side of the end mill 2, the first bottom cutting edge 30 extends from the cutting edge of the first outer peripheral cutting edge 10 to the tip 50a of the protrusion 50. The first bottom cutting edge 30 is curved in shape. The first bottom cutting edge 30 faces in the opposite direction to the outer peripheral surface 8. When the end mill 2 rotates in the first rotational direction R1, the first bottom cutting edge 30 cuts the workpiece in the axial direction of the end mill 2. The cutting edge angle of the first bottom cutting edge 30 can be set as appropriate.

[0044] The second bottom cutting edge 40 is provided at the axial tip of the body portion 4. When the end mill 2 is viewed axially from the tip side of the end mill 2, the second bottom cutting edge 40 extends from the cutting edge of the second outer peripheral cutting edge 20 to the tip 50a of the protrusion 50. The second bottom cutting edge 40 is curved in shape. The second bottom cutting edge 40 faces in the opposite direction to the outer peripheral surface 8. The second bottom cutting edge 40 cuts the workpiece in the axial direction of the end mill 2 when the end mill 2 rotates in the second rotational direction R2. The cutting edge angle of the second bottom cutting edge 40 can be set as appropriate.

[0045] The first bottom cutting edge rake face 32 is provided along the first bottom cutting edge 30. The first bottom cutting edge rake face 32 is integrally formed with the first outer peripheral cutting edge rake face 12. The first bottom cutting edge rake face 32 is connected to the first outer peripheral cutting edge rake face 12. The first bottom cutting edge rake face 32 is the surface that scoops up the cutting chips generated when the first bottom cutting edge 30 cuts the workpiece. The first bottom cutting edge rake face 32 faces forward in the first rotation direction R1 of the end mill 2. The first bottom cutting edge rake face 32 extends from the first bottom cutting edge 30 on the forward side in the first rotation direction R1 of the end mill 2. The rake angle of the first bottom cutting edge rake face 32 can be set as appropriate.

[0046] The second bottom cutting edge rake face 42 is provided along the second bottom cutting edge 40. The second bottom cutting edge rake face 42 is integrally formed with the second outer peripheral cutting edge rake face 22. The second bottom cutting edge rake face 42 is continuous with the second outer peripheral cutting edge rake face 22. The second bottom cutting edge rake face 42 is the surface that scoops up the chips generated when the second bottom cutting edge 40 cuts the workpiece. The second bottom cutting edge rake face 42 faces forward in the second rotation direction R2 of the end mill 2. The second bottom cutting edge rake face 42 extends from the second bottom cutting edge 40 on the forward side of the second rotation direction R2 of the end mill 2. The rake angle of the second bottom cutting edge rake face 42 can be set as appropriate.

[0047] The first bottom cutting edge relief surface 34 is provided along the first bottom cutting edge 30. The first bottom cutting edge 30 is formed at the ridge where the first bottom cutting edge relief surface 34 and the first bottom cutting edge rake face 32 intersect. The first bottom cutting edge relief surface 34 is a surface that avoids friction between the first bottom cutting edge 30 and the workpiece. The first bottom cutting edge relief surface 34 extends from the first bottom cutting edge 30 toward the rear in the first rotational direction R1. The relief angle of the first bottom cutting edge relief surface 34 can be set as appropriate.

[0048] The second bottom cutting edge relief surface 44 is provided along the second bottom cutting edge 40. The second bottom cutting edge 40 is formed at the ridge where the second bottom cutting edge relief surface 44 and the second bottom cutting edge rake face 42 intersect. The second bottom cutting edge relief surface 44 is a surface that avoids friction between the second bottom cutting edge 40 and the workpiece. The second bottom cutting edge relief surface 44 extends from the second bottom cutting edge 40 toward the rear in the second rotation direction R2. The relief angle of the second bottom cutting edge relief surface 44 can be set as appropriate.

[0049] Next, a cutting method for cutting a workpiece using the end mill 2 described above will be explained. The end mill 2 can cut a workpiece by advancing in the radial direction of the end mill 2. In addition, the end mill 2 can cut a workpiece by advancing in the axial direction of the end mill 2.

[0050] In the following section, as an example of a cutting method, a method for grooving the workpiece will be described. As shown in Figures 4 and 5, in the cutting method of this embodiment, the end mill 2 cuts the workpiece 100, thereby forming a groove 102 in the workpiece 100.

[0051] The cutting method of the embodiment comprises a first step and a second step. The first step is to cut the workpiece 100 in the first feed direction F1 by feeding the end mill 2 in the first feed direction F1 (for example, to the right in Figures 4 and 5). The first feed direction F1 is perpendicular to the axial direction of the end mill 2. The first step is performed before the second step.

[0052] The second step is to cut the workpiece 100 in the second feed direction F2 (for example, to the left in Figures 4 and 5) by feeding the end mill 2 in the second feed direction F2. The second step is to cut again the portion that the end mill 2 cut in the first step. The second feed direction F2 is perpendicular to the axial direction of the end mill 2. The second feed direction F2 is opposite to the first feed direction F1. The second step is performed after the first step. The first and second steps will be described in more detail below.

[0053] (1st step) In the first step, the end mill 2 is rotated in the first rotational direction R1. Also in the first step, while the end mill 2 is rotating in the first rotational direction R1, the end mill 2 is fed radially. In the first step, as shown in Figure 4, the end mill 2 is fed in the first feed direction F1. As the end mill 2 moves in the first feed direction F1, the first outer cutting edge 10 of the end mill 2 cuts the workpiece 100 in the first feed direction F1. As the end mill 2 cuts the workpiece 100 in the first feed direction F1, a groove 102 extending in the first feed direction F1 is formed on the workpiece 100.

[0054] In the first step, the end mill 2 is fed in the first feed direction F1 from one end 100a to the other end 100b of the workpiece 100. In the first step, the end mill 2 cuts the workpiece 100 from one end 100a to the other end 100b. As a result, a groove 102 is formed from one end 100a to the other end 100b of the workpiece 100.

[0055] In the first step, the end mill 2 is fed in the first feed direction F1 so that it passes one end 100a of the workpiece 100 in the first feed direction F1. The end mill 2 moves in the first feed direction F1 after passing one end 100a of the workpiece 100. As the end mill 2 passes one end 100a of the workpiece 100, a first opening 104a is formed at one end 100a of the workpiece 100. At this time, burrs may be generated on the workpiece 100 at the first opening 104a.

[0056] In the first step, the end mill 2 is fed in the first feed direction F1 so that it passes the other end 100b of the workpiece 100 in the first feed direction F1. The end mill 2 continues to advance in the first feed direction F1 until it passes the other end 100b of the workpiece 100. As the end mill 2 passes the other end 100b of the workpiece 100, a second opening 104b is formed at the other end 100b of the workpiece 100. At this time, burrs may be generated on the workpiece 100 at the second opening 104b.

[0057] (2nd process) In the second step, the end mill 2 is rotated in the second rotational direction R2. Also in the second step, while the end mill 2 is rotating in the second rotational direction R2, the end mill 2 is fed radially. In the second step, as shown in Figure 5, the end mill 2 is fed in the second feed direction F2. The second feed direction F2 is the opposite direction to the first feed direction F1 in the first step described above. As the end mill 2 moves in the second feed direction F2, the second outer cutting edge 20 of the end mill 2 cuts the workpiece 100 in the second feed direction F2.

[0058] In the second step, the end mill 2 is moved in the second feed direction F2 to cut again the portion that the end mill 2 cut in the first step. In the second step, the end mill 2 is moved in the second feed direction F2 along the groove 102 formed in the workpiece 100 in the first step. As the end mill 2 passes through the groove 102 formed in the workpiece 100 in the first step, the side surface of the groove 102 of the workpiece 100 can be smoothly finished.

[0059] In the second step, the end mill 2 is fed in the second feed direction F2 from the other end 100b of the workpiece 100 to the one end 100a. In the second step, the end mill 2 is fed in the second feed direction F2 so that it passes through the second opening 104b formed in the other end 100b of the workpiece 100 in the first step. The end mill 2 passes through the second opening 104b in the other end 100b of the workpiece 100 and proceeds in the second feed direction F2. The end mill 2 cuts the other end 100b of the workpiece 100 that was cut in the first step again. In the second step, the second opening 104b is cut again as the end mill 2 passes through it. This makes it possible to remove the burrs from the workpiece 100 that were generated at the second opening 104b in the first step.

[0060] Furthermore, in the second step, the end mill 2 is fed in the second feed direction F2 so that it passes through the first opening 104a formed in one end 100a of the workpiece 100 in the first step. The end mill 2 moves in the second feed direction F2 until it passes through the first opening 104a of one end 100a of the workpiece 100. The end mill 2 cuts the end 100a of the workpiece 100 that was cut in the first step again. In the second step, the first opening 104a is cut again as the end mill 2 passes through it. This makes it possible to remove the burrs from the workpiece 100 that were generated at the first opening 104a in the first step.

[0061] (effect) The end mill 2 of the embodiment has been described above. As is clear from the above description, the end mill 2 comprises a first outer peripheral cutting edge 10 that cuts the workpiece when rotating in the first rotational direction R1, and a second outer peripheral cutting edge 20 that cuts the workpiece when rotating in the second rotational direction R2. The first outer peripheral cutting edge 10 and the second outer peripheral cutting edge 20 are positioned at equidistant locations from the central axis C of the end mill 2.

[0062] With this configuration, the workpiece can be cut by the first outer blade 10 and the second outer blade 20, and the cut portion of the workpiece can be finished smoothly. By cutting the portion cut by the first outer blade 10 with the second outer blade 20, the cut portion can be finished smoothly.

[0063] The first outer cutting edge 10 and the second outer cutting edge 20 are straight blades without a helix angle. With this configuration, the workpiece is less likely to be distorted when cutting. As a result, the cut portion of the workpiece can be finished smoothly.

[0064] The end mill 2 has an outer surface 8 that extends in an arc shape from the first outer cutting edge 10 to the second outer cutting edge 20. With this configuration, the end mill 2 rotates smoothly. This allows for a smooth finish on the cut surface of the workpiece.

[0065] The end mill 2 is equipped with a protrusion 50 that projects toward the central axis C of the end mill 2 between the first outer rake face 12 and the second outer rake face 22. With this configuration, the cutting chips generated when the first outer rake face 10 and the second outer rake face 20 cut the workpiece can be smoothly discharged.

[0066] The end mill 2 is equipped with a first bottom cutting edge 30 and a second bottom cutting edge 40 that cut the workpiece in the axial direction of the end mill 2. With this configuration, the workpiece can be cut along the axial direction of the end mill 2.

[0067] Furthermore, when the object to be cut is made from a material containing at least one of synthetic rubber, natural rubber, and synthetic resin (for example, urethane), burrs tend to form on the cut surface. However, with the end mill 2 described above, even if the object to be cut is made from the above material (for example, urethane), the cut surface can be finished smoothly.

[0068] Furthermore, the cutting method for cutting a workpiece using the end mill 2 described above comprises a first step of cutting the workpiece by rotating the end mill 2 in a first rotational direction R1 and feeding the end mill 2 in a first feed direction F1, and a second step of cutting the workpiece by rotating the end mill 2 in a second rotational direction R2 and feeding the end mill 2 in a second feed direction F2 in the portion cut by the end mill 2 in the first step.

[0069] With this configuration, the cut portion can be smoothly finished by cutting the portion cut by the first outer peripheral blade 10 in the first step with the second outer peripheral blade 20 in the second step. The cut portion can be smoothly finished by cutting the portion cut in the first step in the opposite direction in the second step.

[0070] Furthermore, burrs tend to form at the ends of the workpiece, but with the above cutting method, the ends of the workpiece that were cut by the first outer peripheral blade 10 in the first step are cut by the second outer peripheral blade 20 in the second step, thereby making the cut portion at the ends of the workpiece smooth.

[0071] (modified version) In the above embodiment, the end mill 2 was fed in the second feed direction F2 in the second step of the cutting method, but the configuration is not limited to this. In a modified example, the end mill 2 may be fed in the first feed direction F1 in the second step. In the portion of the workpiece that was cut in the first feed direction F1 in the first step, the end mill 2 may cut the workpiece again in the first feed direction F1 in the second step.

[0072] In the above embodiment, the first rotational direction R1 was clockwise and the second rotational direction R2 was counterclockwise. However, in the modified example, the first rotational direction R1 may be counterclockwise and the second rotational direction R2 may be clockwise.

[0073] In the above embodiment, the first feed direction F1 was to the right and the second feed direction F2 was to the left. However, in a modified example, the first feed direction F1 may be to the left and the second feed direction F2 may be to the right.

[0074] In the above embodiment, the first feed direction F1 was linear, but in the modified version, the first feed direction F1 may be curved. Similarly, in the above embodiment, the second feed direction F2 was linear, but in the modified version, the second feed direction F2 may be curved.

[0075] In the above embodiment, one end 100a and the other end 100b of the cutting target 100 were located at opposite ends of the cutting target 100, but the configuration is not limited to this. In a modified example, one end 100a and the other end 100b of the cutting target 100 may be located at the same end of the cutting target 100. The positions of one end 100a and the other end 100b of the cutting target 100 are not particularly limited.

[0076] In the above embodiment, the first outer blade 10 was a straight blade configuration without a helix angle, but in a modified example, the first outer blade 10 may be a helical blade configuration having a helix angle.

[0077] Similarly, in the above embodiment, the second outer blade 20 was a straight blade without a helix angle, but in a modified example, the second outer blade 20 may be a helical blade with a helix angle. When the first outer blade 10 and the second outer blade 20 are helical blades, the workpiece can be cut smoothly, and the cut portion of the workpiece can be finished smoothly.

[0078] In the above embodiment, a method for machining a workpiece into grooves was described, but the machining method using the end mill 2 is not particularly limited. The end mill 2 can machine a workpiece into grooves, side milling, tapering, contouring, counterboring, etc.

[0079] In the above embodiment, the end mill 2 was equipped with a first bottom cutting edge 30 and a second bottom cutting edge 40, but in the modified example, the end mill 2 may not be equipped with these.

[0080] Although specific examples of the present invention have been described in detail above, these are merely illustrative and do not limit the scope of the claims. The technologies described in the claims include various modifications and changes to the specific examples illustrated above. The technical elements described in this specification or drawings exhibit technical usefulness individually or in various combinations, and are not limited to the combinations described in the claims at the time of filing. Furthermore, the technologies illustrated in this specification or drawings can achieve multiple objectives simultaneously, and achieving even one of these objectives itself constitutes technical usefulness. [Explanation of symbols]

[0081] 2: End mill, 4: Body, 6: Shank, 8: Outer surface, 10: First outer cutting edge, 12: First outer cutting edge rake face, 14: First outer cutting edge relief face, 20: Second outer cutting edge, 22: Second outer cutting edge rake face, 24: Second outer cutting edge relief face, 30: First bottom cutting edge, 32: First bottom cutting edge rake face, 34: First bottom cutting edge relief face, 40: Second bottom cutting edge, 42: Second bottom cutting edge rake face, 44: Second bottom cutting edge relief face, 50: Protrusion, 100: Cutting object, 100a: One end, 100b: Other end, 102: Groove, 104a: First opening, 104b: Second opening, C: Central axis, F1: First feed direction, F2: Second feed direction, R1: First rotation direction, R2: Second rotation direction

Claims

1. An end mill for cutting an object, A first outer cutting edge that cuts the object to be cut when rotating in the first rotational direction, It comprises a second outer cutting edge that cuts the workpiece when rotating in a second rotation direction opposite to the first rotation direction, An end mill in which the first outer peripheral cutting edge and the second outer peripheral cutting edge are located at positions equidistant from the central axis of the end mill.

2. The end mill according to claim 1, wherein the first outer cutting edge and the second outer cutting edge are straight cutting edges without a helix angle.

3. The end mill according to claim 1, wherein the first outer peripheral cutting edge and the second outer peripheral cutting edge are helical cutting edges having a helix angle.

4. The end mill according to any one of claims 1 to 3, further comprising an outer peripheral surface extending in an arc shape from the first outer peripheral cutting edge to the second outer peripheral cutting edge.

5. The first outer cutting edge rake surface scoops up the cutting chips generated when the first outer cutting edge cuts the workpiece, The second outer cutting edge rake surface scoops up the cutting chips generated when the second outer cutting edge cuts the workpiece, The end mill according to any one of claims 1 to 3, further comprising a convex portion projecting toward the central axis of the end mill between the first outer rake face and the second outer rake face.

6. A first bottom cutting edge that cuts the workpiece in the axial direction of the end mill when it rotates in the first rotational direction, The end mill according to any one of claims 1 to 3, further comprising a second bottom cutting edge that cuts the workpiece in the axial direction of the end mill when it rotates in the second rotational direction.

7. The end mill according to any one of claims 1 to 3, wherein the material to be cut is made from a material comprising at least one of synthetic rubber, natural rubber, and synthetic resin.

8. The end mill according to claim 7, wherein the workpiece to be cut is made of urethane.

9. A cutting method for cutting an object using an end mill according to any one of claims 1 to 3, A first step involves cutting the workpiece while the end mill is rotated in the first rotational direction, A cutting method comprising: a second step of cutting the workpiece while rotating the end mill in the second rotational direction in the portion cut by the end mill in the first step.

10. In the first step described above, the workpiece is cut by feeding the end mill in the first feed direction, The cutting method according to claim 9, wherein in the second step, the workpiece is cut by feeding the end mill in a second feed direction opposite to the first feed direction.

11. The cutting method according to claim 9, wherein the second step involves cutting again the end of the object to be cut that was cut by the end mill in the first step.

Images