WO2018061355A1 - Cutting tool - Google Patents

Abstract

A cutting tool according to an embodiment of the disclosure comprises: a rake face; a flank face continuous with the rake face; and a cutting edge constituted by a ridgeline between the rake face and the flank face. The cutting tool according to an embodiment of the disclosure comprises: a base material having a first face which is the face on the rake face side, and a second face which is the face on the flank face side; and a diamond layer covering the first face and the second face. A portion of the flank face is constituted by the base material. The portion of the flank face constituted by the base material is located between the diamond layer covering the first face and the diamond layer covering the second face.

Description

Cutting tools

This disclosure relates to a cutting tool. This application claims the priority based on Japanese Patent Application No. 2016-191641, which is a Japanese patent application filed on September 29, 2016. All the descriptions described in the Japanese patent application are incorporated herein by reference.

Conventionally, a cutting tool described in JP-A-2015-85462 (Patent Document 1) is known as a cutting tool in which a base material is coated with a diamond layer. The tool main body of the cutting tool described in Patent Document 1 has a flank, a rake face, and a cutting edge formed on the ridge line of the flank and the rake face. The tool body is covered with a hard coating.

In the cutting tool described in Patent Document 1, in order to improve the sharpness of the cutting tool, the hard coating covering the rake face side of the tool body is removed by a laser or the like.

Japanese Patent Laying-Open No. 2015-85462

The cutting tool according to an aspect of the present disclosure includes a rake face, a flank face connected to the rake face, and a cutting edge constituted by a ridge line between the rake face and the flank face. A cutting tool according to an aspect of the present disclosure covers a base material having a first surface that is a rake face side surface and a second surface that is a flank face side, and covers the first surface and the second surface. With a diamond layer. A part of the flank is constituted by a base material. A part of the flank formed by the base material is located between the diamond layer covering the first surface and the diamond layer covering the second surface.

FIG. 1 is a top view of the cutting tool according to the first embodiment. FIG. 2 is an enlarged top view of region II in FIG. FIG. 3 is a schematic diagram of cutting using the cutting tool according to the first embodiment. 4 is a cross-sectional view taken along line IV-IV in FIG. FIG. 5 is a process diagram of the manufacturing method of the cutting tool according to the first embodiment. FIG. 6 is a cross-sectional view of the cutting tool according to the first embodiment after the diamond layer forming step is completed and before the diamond layer removing step is performed. FIG. 7 is a cross-sectional view of the cutting tool according to the first embodiment after the end of the rake face treatment process and before the flank face treatment process. FIG. 8 is a cross-sectional view in a cross section perpendicular to the cutting edge of the cutting tool according to the second embodiment. FIG. 9 is a cross-sectional view in a cross section perpendicular to the cutting edge of the cutting tool according to the comparative example.

[Problems to be solved by this disclosure]
In the cutting tool described in Patent Document 1, a hard coating covers the flank side of the tool body. This hard coating is easily peeled off from the flank side of the tool body by the main component force that the cutting tool receives from the work material during cutting. Therefore, the durability of the cutting tool described in Patent Document 1 is not sufficient.

The present disclosure has been made in view of the above-described problems of the prior art. More specifically, the present disclosure provides a cutting tool that can suppress peeling of a diamond layer covering a flank side surface of a substrate.
[Effects of the present disclosure]
According to the above, peeling of the diamond layer covering the flank side surface of the substrate can be suppressed.

[Description of Embodiment of the Present Disclosure]
First, embodiments of the present disclosure will be listed and described.

(1) A cutting tool according to an aspect of the present disclosure includes a rake face, a flank face continuous with the rake face, and a cutting edge constituted by a ridge line between the rake face and the flank face. A cutting tool according to an aspect of the present disclosure covers a base material having a first surface that is a rake face side surface and a second surface that is a flank face side, and covers the first surface and the second surface. With a diamond layer. A part of the flank is constituted by a base material. A part of the flank formed by the base material is located between the diamond layer covering the first surface and the diamond layer covering the second surface.

According to the cutting tool of (1), peeling of the diamond layer covering the flank side surface of the substrate can be suppressed.

(2) In the cutting tool of (1), the first surface is connected to the first top surface that is continuous with the second surface and the first top surface, and the first top surface is sandwiched between the second surface and the first top surface. The second top surface may be included. The angle formed by the first top surface and the second top surface may be a negative angle in a cross section perpendicular to the cutting edge.

According to the cutting tool of (2), peeling of the diamond layer can be further suppressed.
(3) In the cutting tool of (2), in the cross section perpendicular to the cutting edge, the distance in the direction parallel to the ridgeline between the first top surface and the second top surface and the rake face of the cutting edge is 0.001 μm or more. It may be 5 μm or less.

According to the cutting tool of (3), flank separation of the diamond layer can be suppressed by thickly covering the first top surface with the diamond layer.

(4) In the cutting tools of (1) to (3), the thickness of the diamond layer covering the first surface of the substrate may be 0.1 μm or more and 50 μm or less.

(4) According to the cutting tool of (4), the flank peeling of the diamond layer can be further suppressed.

(5) In the cutting tools of (1) to (4), the radius of curvature of the cutting edge tip may be not less than 0.01 μm and not more than 10 μm.

According to the cutting tool of (5), it is possible to improve the sharpness of the cutting tool while suppressing the peeling of the diamond layer covering the flank side surface of the substrate.

[Details of Embodiment of the Present Disclosure]
Details of the embodiment of the present disclosure will be described below with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals. Moreover, you may combine arbitrarily at least one part of embodiment described below.

(First embodiment)
The configuration of the cutting tool according to the first embodiment will be described below.

FIG. 1 is a top view of the cutting tool according to the first embodiment. The cutting tool according to the first embodiment has a tip portion 1, a body portion 2, and a shank portion 3. The cutting tool according to the embodiment is a ball end mill. The cutting tool according to the first embodiment is not limited to the ball end mill. For example, the cutting tool according to the first embodiment may be a radius end mill or the like.

FIG. 2 is an enlarged top view of region II in FIG. As shown in FIG. 2, the cutting tool according to the first embodiment has a rake face 11 and a flank 12 (see FIG. 4) at the distal end portion 1. The rake face 11 is continuous with the flank face 12. A ridge line between the rake face 11 and the flank face 12 forms a cutting edge 13.

FIG. 3 is a schematic diagram of cutting using the cutting tool according to the first embodiment. As shown in FIG. 3, in the cutting tool according to the first embodiment, the cutting edge 13 is urged against the work material while rotating about the central axis A. As a result, the work material is cut.

FIG. 4 is a cross-sectional view taken along IV-IV in FIG. As shown in FIG. 4, the cutting tool according to the first embodiment includes a base material 4 and a diamond layer 5. The substrate 4 has a first surface 41 (top surface) and a second surface 42. The first surface 41 is a surface of the base material 4 on the rake face 11 side. The second surface 42 is a surface on the flank 12 side of the substrate 4.

The base material 4 may have a third surface 43. The third surface 43 is connected to the first surface 41 and the second surface 42 and is disposed at a position sandwiched between the first surface 41 and the second surface 42. The angle formed by the third surface 43 and the first surface 41 is an angle θ1. The angle θ1 is greater than 0 ° and less than 90 °.

The base material 4 is covered with a diamond layer 5. More specifically, the first surface 41 and the second surface 42 of the substrate 4 are covered with the diamond layer 5, but the third surface 43 of the substrate 4 is not covered with the diamond layer 5. That is, a part of the flank 12 is configured by the base material 4 (third surface 43). A part (third surface 43) of the flank 12 constituted by the base material 4 covers the diamond layer 5 covering the first surface of the base material 4 and the second surface of the base material 4. It is located between the diamond layer 5.

From another point of view, the diamond layer 5 covering the first surface 41 of the substrate 4 and the diamond layer 5 covering the second surface 42 of the substrate 4 are continuous. Absent. The diamond layer 5 covering the first surface 41 of the base material 4 and the diamond layer 5 covering the second surface 42 of the base material 4 are discontinuous in part of the cutting edge 13. It only has to be. In particular, the diamond layer 5 covering the first surface 41 of the substrate 4 and the diamond layer 5 covering the second surface 42 of the substrate 4 are at least near the tip 1a of the cutting tool according to the embodiment. It is preferable that it is discontinuous in the cutting edge 13 located in the position. This is because in the vicinity of the tip 1a, the peripheral speed is close to zero during processing, and the load during cutting is particularly large.

It is preferable that a part of the flank 12 (the third surface 43) constituted by the base material 4 is preferably arranged away from the cutting edge 13.

The thickness of the diamond layer 5 covering the first surface 41 of the substrate 4 is a thickness h. The thickness h is preferably 0.1 μm or more and 50 μm or less.

For the base material 4, for example, a cemented carbide which is a sintered body containing a powder such as WC (tungsten carbide) and a binder such as Co (cobalt) is used. In addition, the material used for the base material 4 is not restricted to this.

The diamond layer 5 is, for example, a layer containing diamond crystals. The diamond layer 5 is, for example, a diamond polycrystalline film. The diamond layer 5 may contain a non-diamond component (for example, an amorphous component). The diamond layer 5 may not contain diamond crystals. For example, the diamond layer 5 may be a DLC (Diamond Like Carbon) layer.

The radius of curvature at the tip of the cutting edge 13 is a radius of curvature R. The curvature radius R is preferably 0.01 μm or more and 10 μm or less.

Below, the manufacturing method of the cutting tool which concerns on 1st Embodiment is demonstrated.
FIG. 5 is a process diagram of the manufacturing method of the cutting tool according to the first embodiment. As shown in FIG. 5, the manufacturing method of the cutting tool according to the first embodiment includes a diamond layer forming step S1 and a diamond layer removing step S2. The diamond layer removal step S2 may include a rake face treatment step S21 and a flank face treatment step S22.

FIG. 6 is a cross-sectional view of the cutting tool according to the first embodiment after the diamond layer forming step S1 is completed and before the diamond layer removing step S2 is performed. As shown in FIG. 6, in the diamond layer forming step S <b> 1, the diamond layer 5 is formed on the substrate 4, and the substrate 4 is covered with the diamond layer 5. The diamond layer 5 is formed by using, for example, HFCVD (Hot Filament Chemical Vapor Deposition).

In this stage, the periphery of the tip of the cutting tool according to the first embodiment is rounded. This is because when the diamond layer 5 is formed, the temperature around the tip of the cutting tool according to the first embodiment is higher than that of the other portions, so that the formation of the diamond layer 5 is promoted.

In the diamond layer removing step S2, the diamond layer 5 covering the base material 4 is partially removed. In the diamond layer removing step S <b> 2, the base material 4 is exposed from the flank 12 by removing the diamond layer 5 covering the second surface 42 of the base material 4.

FIG. 7 is a cross-sectional view of the cutting tool according to the first embodiment after the end of the rake face treatment step S21 and before the flank face treatment step S22 is performed. As shown in FIG. 7, in the rake face treatment step S <b> 21, the diamond layer 5 covering the first face 41 of the base material 4 is partially removed. By partially removing the diamond layer 5 covering the first surface 41 of the base material 4, the roundness on the rake face 11 side at the tip of the cutting tool according to the first embodiment is flattened.

The removal of the diamond layer 5 is performed by irradiating a laser on the rake face 11 side. The laser used for removing the diamond layer 5 is, for example, a second harmonic of a YVO ₄ laser.

In the flank processing step S22, the diamond layer 5 covering the second surface 42 of the base material 4 is partially removed. Partial removal of the diamond layer 5 covering the second surface 42 of the substrate 4 is continued until the substrate 4 is exposed from the flank 12. Thereby, the structure of the cutting tool according to the first embodiment shown in FIG. 4 is formed.

With the partial removal of the diamond layer 5 covering the second surface 42 of the base material 4, the roundness on the flank side of the tip of the cutting tool according to the first embodiment is flattened. Thereby, the cutting edge 13 of the cutting tool according to the first embodiment is sharpened, and the cutting edge 13 having a curvature radius R of 0.01 μm or more and 10 μm or less is obtained.

The removal of the diamond layer 5 covering the second surface 42 of the substrate 4 is performed by irradiating a laser on the flank 12 side. The laser used for removing the diamond layer 5 is, for example, a second harmonic of a YVO ₄ laser.

(Second Embodiment)
The configuration of the cutting tool according to the second embodiment will be described below. In the following, differences from the cutting tool according to the first embodiment will be mainly described, and the same description will not be repeated.

FIG. 8 is a cross-sectional view in a cross section perpendicular to the cutting edge 13 of the cutting tool according to the second embodiment. As shown in FIG. 8, the cutting tool according to the second embodiment has a rake face 11, a flank face 12, and a cutting edge 13. The cutting tool according to the second embodiment has a base material 4 and a diamond layer 5.

In the cutting tool according to the second embodiment, the base material 4 is exposed from the flank 12 (that is, a part of the flank 12 is constituted by the base material 4), and is constituted by the base material 4. A part of the flank 12 is located between the diamond layer 5 covering the first surface 41 of the substrate 4 and the diamond layer 5 covering the second surface 42 of the substrate 4. Yes.

In these respects, the cutting tool according to the second embodiment is common to the cutting tool according to the first embodiment. On the other hand, the cutting tool according to the second embodiment is different from the cutting tool according to the first embodiment in the following points.

In the cutting tool according to the second embodiment, the first surface 41 of the substrate 4 has a first top surface 41a and a second top surface 41b. The first top surface 41 a is continuous with the second surface 42 of the substrate 4. The second top surface 41b is continuous with the first top surface 41a. The second top surface 41 b is disposed at a position where the first top surface 41 a is sandwiched between the second top surface 41 b and the second surface 42 of the substrate 4.

The angle formed by the first top surface 41a and the second top surface 41b is an angle θ2. The angle θ2 is a negative angle. The angle θ2 is a negative angle when the cutting tool is disposed with the second top surface 41b facing upward and the cutting edge 13 facing leftward. The first top surface 41a is the second top surface. This is a case where the rotation is counterclockwise with respect to 41b around the boundary line between the first top surface 41a and the second top surface 41b. From another point of view, the angle θ2 is a negative angle when the cutting tool is disposed with the second top surface 41b facing upward and the cutting edge 13 facing left. This refers to the case where the surface 41a is inclined leftward with respect to the second top surface 41b.

The thickness of the diamond layer 5 covering the first top surface 41a of the substrate 4 is a thickness h1. The thickness h <b> 1 is the distance between the ridge line between the first top surface 41 a and the second surface 42 and the rake surface 11. The thickness of the diamond layer 5 covering the second top surface 41b of the substrate 4 is a thickness h2. The thickness h <b> 2 is a distance between the second top surface 41 b and the rake surface 11. Since the angle θ2 is a negative angle, thickness h1> thickness h2.

The distance between the ridgeline between the first top surface 41a and the second top surface 41b and the cutting edge 13 is a distance L. The distance L is a distance in a direction parallel to the rake face 11 in a cross section perpendicular to the cutting edge 13. The distance L is preferably 0.001 μm or more and 5 μm or less.

Hereinafter, a method for manufacturing a cutting tool according to the second embodiment will be described. The cutting tool manufacturing method according to the second embodiment includes a diamond layer forming step S1 and a diamond layer removing step S2, similar to the cutting tool manufacturing method according to the first embodiment. The layer removal step S2 has a rake face treatment step S21 and a flank face treatment step S22.

However, the manufacturing method of the cutting tool according to the second embodiment is the first in that the first surface 41 of the substrate 4 to be used has the first top surface 41a and the second top surface 41b. It differs from the manufacturing method of the cutting tool which concerns on embodiment.

(Effects of the cutting tool according to the first embodiment and the cutting tool according to the second embodiment)
The effects of the cutting tool according to the first embodiment and the cutting tool according to the second embodiment will be described below.

First, the effect of the cutting tool according to the first embodiment will be described by comparing it with a comparative example. FIG. 9 is a cross-sectional view in a cross section perpendicular to the cutting edge 13 of the cutting tool according to the comparative example. As shown in FIG. 9, the cutting tool according to the comparative example has a rake face 11, a flank face 12, and a cutting edge 13. The cutting tool according to the comparative example has a base material 4 and a diamond layer 5.

In the cutting tool according to the comparative example, the diamond layer 5 covers the first surface 41 and the second surface 42 of the base 4, and the base 4 is not exposed from the flank 12. That is, in the cutting tool according to the comparative example, the diamond layer 5 covers the first surface 41 and the second surface 42 of the base material 4 continuously (without a break).

When cutting is performed using the cutting tool according to the comparative example, the main component force (cutting force in the direction from the rake face 11 toward the flank 12) is applied to the rake face 11 near the cutting edge 13. . In the cutting tool according to the comparative example, the diamond layer 5 covers the first surface 41 and the second surface 42 of the base material 4 continuously (without breaks), so that the main component force is the first component force of the base material 4. It tends to act on the diamond layer 5 covering the two surfaces 42. As a result, in the cutting tool according to the comparative example, the flank peeling of the diamond layer 5 tends to occur.

On the other hand, as described above, in the cutting tool according to the first embodiment, a part of the flank 12 is constituted by the base material 4, and a part of the flank 12 constituted by the base material 4. Is located between the diamond layer 5 covering the first surface 41 of the substrate 4 and the diamond layer 5 covering the second surface of the substrate 4. That is, the diamond layer 5 covering the first surface 41 of the substrate 4 and the diamond layer 5 covering the second surface 42 of the substrate 4 are not continuous at least at a part of the cutting edge 13. .

Therefore, in the cutting tool according to the first embodiment, the main component force generated on the rake face 11 when performing the cutting process hardly acts on the diamond layer 5 covering the second surface 42 of the base material 4. . As a result, according to the cutting tool according to the first embodiment, flank separation of the diamond layer 5 can be suppressed.

Subsequently, the effect of the cutting tool according to the second embodiment will be described. As described above, in the cutting tool according to the second embodiment, the first surface 41 of the base material 4 has the first top surface 41a and the second top surface 41b, and the angle θ2 is a negative angle. It has become. Therefore, in the cutting tool according to the second embodiment, the diamond layer 5 is in contact with the first surface 41 of the base material 4 with a wider area than the cutting tool according to the first embodiment. Therefore, according to the cutting tool which concerns on 2nd Embodiment, peeling of the diamond layer 5 can further be suppressed.

As described above, in the cutting tool according to the second embodiment, thickness h1> thickness h2. Therefore, in the cutting tool according to the second embodiment, the thickness of the diamond layer 5 covering the first surface 41 of the substrate 4 in the vicinity of the cutting edge 13 can be ensured. Therefore, according to the cutting tool according to the second embodiment, flank separation can be further suppressed.

It should be considered that the embodiment disclosed this time is illustrative in all respects and not restrictive. The scope of the present invention is shown not by the above-described embodiment but by the scope of claims, and is intended to include meanings equivalent to the scope of claims and all modifications within the scope.

1 tip part, 1a cutting tool tip, 11 rake face, 12 flank face, 13 cutting edge, 2 body part, 3 shank part, 4 base material, 41 1st face, 41a 1st top face, 41b 2nd top face , 42 2nd surface, 43 3rd surface, 5 diamond layer, A center axis, h, h1, h2 thickness, L distance, R radius of curvature, S1 diamond layer formation step, S2 diamond layer removal step, S21 rake face treatment Process, S22 treatment process, θ1, θ2 angle.

Claims (5)

A cutting tool comprising a rake face, a flank face connected to the rake face, and a cutting edge constituted by a ridge line between the rake face and the flank face,
A base material having a first surface that is the rake face side surface and a second surface that is the flank face side;
A diamond layer covering the first surface and the second surface;
A part of the flank is constituted by the base material,
The part of the flank constituted by the base material is located between the diamond layer covering the first surface and the diamond layer covering the second surface. ,Cutting tools. The first surface is arranged so as to sandwich the first top surface between the first top surface continuous with the second surface and the first top surface and between the second surface and the second top surface. Including the top surface,
The cutting tool according to claim 1, wherein an angle formed by the first top surface and the second top surface is a negative angle in a cross section perpendicular to the cutting edge. In a cross section perpendicular to the cutting edge, a distance in a direction parallel to the rake face between the ridge line between the first top surface and the second top surface and the cutting edge is 0.001 μm or more and 5 μm or less. Item 3. The cutting tool according to Item 2. The cutting tool according to any one of claims 1 to 3, wherein a thickness of the diamond layer covering the first surface of the base material is not less than 0.1 µm and not more than 50 µm. The cutting tool according to any one of claims 1 to 4, wherein a radius of curvature of a tip of the cutting edge is 0.01 µm or more and 10 µm or less.

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