TW202206207A - Tool and tool production method - Google Patents

Abstract

This tool comprises a tip portion that is formed from binderless cubic boron nitride. The tip portion has a surface which comes into contact with a workpiece. At least a portion of said surface contains a plurality of first recesses, and protrusions that are each formed by the contact between the edges of two adjacent first recesses.

Description

Tools and methods of making tools

The present invention relates to a tool and a method for manufacturing the tool.

Patent Document 1 (Japanese Patent Laid-Open No. 2017-119333 ) describes a spherical end mill. The spherical end mill of Patent Document 1 has a body portion and a blade portion. The blade portion is attached to the front end of the body portion. The blade portion is formed of a diamond sintered body including diamond particles and a binder. The blade has a hemispherical shape. The surface of the blade portion includes a concave portion and a convex portion. [Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2017-119333

The tool of the present invention has a front end formed from binderless cubic boron nitride. The front end has a surface in contact with the workpiece. At least a part of the surface includes a plurality of first concave portions and a protruding portion formed by mutual contact between ends of two adjacent first concave portions.

[Problems to be Solved by the Invention] According to the knowledge obtained by the inventors of the present invention, the spherical end mill described in Patent Document 1 has room for improvement in terms of contactability with the workpiece.

The present invention has been accomplished in view of the above-mentioned problems of the prior art. More specifically, the present invention provides a tool with improved contact with a workpiece (a machining tool or a cutting tool with improved machining accuracy of the workpiece, or a measuring tool with reduced contact resistance with the workpiece).

[Effect of the present invention] According to the tool of the present invention, the contact with the workpiece can be improved (in the case of a machining tool or a cutting tool, the machining accuracy of the workpiece can be improved, and in the case of a measuring tool, the contact resistance with the workpiece can be reduced).

[Description of Embodiments of the Present Invention] First, an embodiment of the present invention will be described.

(1) The tool of one aspect of the present invention includes a front end portion formed of binderless cubic boron nitride. The front end has a surface in contact with the workpiece. At least a part of the surface includes a plurality of first concave portions and a protruding portion formed by mutual contact between ends of two adjacent first concave portions. According to the tool of one aspect of the present invention, the contactability with the workpiece can be improved.

(2) The tool of (1) above may be a measuring tool for measuring the surface roughness or shape of the workpiece. In this case, the contact resistance between the front end portion and the workpiece when scanning along the surface of the workpiece can be reduced.

(3) The tool of (1) above may also be a processing tool for machining workpieces. In this case, the machining accuracy in machining the workpiece can be improved.

(4) In the tool of (3) above, the surface may include a partial spherical surface.

(5) In the tool of the above (4), the surface may include grooves, and cutting edges formed at ridges of the grooves and part of the spherical surface.

(6) The tool of (1) above may also be a cutting tool for cutting workpieces. The surface may include a cutting surface, a flank surface, and a cutting edge formed at the ridgeline of the cutting surface and the flank surface. In this case, the machining accuracy in machining the workpiece can be improved.

(7) In the tool of the above (3) to (6), the depth of the first concave portion may be 0.05 μm or more and 20 μm or less. In this case, the machining accuracy in machining the workpiece can be improved.

(8) In the tools of (3) to (7) above, the arithmetic mean roughness of the surface of the first recessed portion may be 0.05 μm or more and 1.5 μm or less. In this case, the durability of the tool can be improved.

(9) In the tool of the above (3) to (8), the deflection parameter of the surface portion on which the first recessed portion and the protruding portion are formed may exceed 0. In this case, the machining accuracy in machining the workpiece can be further improved.

(10) In the tool of the above (3) to (9), at least a part of the surface may include a second recessed portion different from the first recessed portion. The depth of the second recess may be 1 μm or more. In this case, the durability of the tool can be improved.

(11) In the tool of (10) above, the circle-equivalent diameter of the second concave portion in plan view may be 0.5 μm or more and 50 μm or less. In this case, the durability of the tool can be further improved.

(12) In the tool of the above (10) or (11), the area ratio of the second recess in the surface may be 3% or more and 80% or less. In this case, the durability of the tool can be further improved.

(13) A method of manufacturing a tool according to an aspect of the present invention includes the steps of: preparing a front end portion to be formed from adhesiveless cubic boron nitride; and forming at least a part of the surface of the front end portion by irradiating a laser A plurality of first recesses. A protrusion is formed in a part of the surface of a front-end|tip part by the end of two adjacent 1st recessed parts being connected.

(14) The method for manufacturing a tool according to (13) may further include the step of forming a cutting surface and a belly surface connected to the cutting surface on the surface of the front end portion by irradiating a laser.

[Details of Embodiments of the Present Invention] Next, the details of the embodiments of the present invention will be described with reference to the accompanying drawings. In the following drawings, the same or corresponding parts are denoted by the same reference numerals, and the description thereof will not be repeated.

(first embodiment) Hereinafter, the structure of the tool of 1st Embodiment is demonstrated. The tool of the first embodiment is a cutting tool for cutting a workpiece. More specifically, the tool of the first embodiment is the spherical end mill 100 . The workpiece is made of, for example, a steel material. The workpiece may also be made of titanium alloy.

FIG. 1 is a side view of a ball end mill 100 . FIG. 2 is an enlarged view of area II of FIG. 1 . As shown in FIGS. 1 and 2 , the spherical end mill 100 has a rotation axis A. As shown in FIG. The spherical end mill 100 processes the workpiece by rotating about the rotation axis A. As shown in FIG. The spherical end mill 100 has a main body portion 10 and a front end portion 20 .

The main body portion 10 is formed of, for example, a cemented carbide. The body portion 10 has a first end 10a and a second end 10b in the direction along the rotation axis A. As shown in FIG. The second end 10b is the end on the opposite side of the first end 10a. The main body 10 has a handle 11 and a neck 12 . The handle 11 is located on the side of the first end 10a, and the neck 12 is located on the side of the second end 10b.

The handle 11 extends along the axis of rotation A. The handle 11 has a first end 11a and a second end 11b in the direction along the rotation axis A. As shown in FIG. The first end 11a coincides with the first end 10a. The second end 11b is the end on the opposite side of the first end 11a. The handle 11 has a circular shape when viewed in a cross-section perpendicular to the rotation axis A. As shown in FIG.

The neck portion 12 extends along the rotation axis A from the second end 11b. The neck 12 has a first end 12a and a second end 12b in the direction along the rotation axis A. As shown in FIG. The first end 12a is the end on the handle 11 side. The second end 12b is the end on the opposite side of the first end 12a, and corresponds to the second end 10b. The neck portion 12 has a circular shape when viewed in a cross-section perpendicular to the rotation axis A. As shown in FIG. The cross-sectional area of the neck 12 is smaller than the cross-sectional area of the handle 11 when viewed in a cross-section perpendicular to the axis of rotation A.

The front end portion 20 is attached to the main body portion 10 by, for example, brazing. More specifically, the distal end portion 20 is attached to the second end 10 b via the connection layer 13 . The connection layer 13 is copper solder.

The front end portion 20 is formed of binderless cubic boron nitride. The binderless cubic boron nitride includes a plurality of cubic boron nitride grains. The remainder of the binderless cubic boron nitride may contain boron nitride with other crystal structures (wurtzite boron nitride, hexagonal boron nitride) and unavoidable impurities, but no binder. That is, in the binderless cubic boron nitride, each of the plurality of cubic boron nitride crystal grains is directly bonded to each other. In addition, the amount of boron nitride (wurtzite boron nitride, hexagonal boron nitride) and unavoidable impurities with other crystal structures is as small as possible, but sometimes contains several percentages of the total mass. .

In the binderless cubic boron nitride, the average grain size of the cubic boron nitride is less than 1 μm. In the binderless cubic boron nitride, the average grain size of the cubic boron nitride is preferably 10 nm or more and 500 nm or less. In the binderless cubic boron nitride, the average grain size of the cubic boron nitride crystal grains may be not less than 100 nm and not more than 500 nm, and may also be not less than 100 nm and not more than 300 nm.

The average particle size of the cubic boron nitride grains in the binderless cubic boron nitride can be measured by the following operation: after the surface of the front end portion 20 is precisely ground, for example, using JSM- 7800F and other electron microscopes, set the observation conditions where grain boundaries can be seen, acquire reflection electron microscope images, and perform image analysis.

The front end portion 20 has a surface 21 . The front end portion 20 has a hemispherical shape. That is, the surface 21 includes a partial spherical surface 21a. Let the diameter of the hemisphere constituting the tip portion 20 be the diameter R. When the workpiece is machined by the spherical end mill 100, the surface 21 (part of the spherical surface 21a) is in contact with the workpiece.

Surface 21 contains grooves 21b. The surface 21 is recessed at the groove 21b. The grooves 21b extend radially from the vicinity of the central portion of the surface 21 . The ridgeline between the groove 21b and the partial spherical surface 21a is the cutting edge 21c. The partial spherical surface 21a is the belly surface of the blade. The surface of the groove 21b connected to the cutting edge 21c is the cutting surface.

FIG. 3 is a schematic top view of a portion of the spherical surface 21 a in the spherical end mill 100 . FIG. 4 is a cross-sectional view taken along line IV-IV of FIG. 3 . As shown in FIGS. 3 and 4 , a plurality of first recesses 22 are formed on the partial spherical surface 21a. The partial spherical surface 21 a is recessed at the first recess 22 .

In the example of FIG. 3 , the first concave portion 22 has a hexagonal shape in plan view (viewed from a direction perpendicular to the partial spherical surface 21 a ), but the planar shape of the first concave portion 22 is not limited to this. The 1st recessed part 22 is formed over the whole surface of the partial spherical surface 21a, for example. The first concave portion 22 may be formed only in a part of the partial spherical surface 21a.

A protrusion 23 is formed on the partial spherical surface 21a. The protruding portion 23 is formed by contacting ends of two adjacent first recessed portions 22 . Since the protruding portion 23 is formed by contacting the ends of the two adjacent first concave portions 22, the front end thereof is sharp (the front end does not include a flat surface).

The first recessed portion 22 has a depth D1. The depth D1 is the distance between the bottom of the first concave portion 22 and the front end of the protruding portion 23 . The depth D1 is preferably 0.05 μm or more and 20 μm or less.

The arithmetic mean roughness (Ra) of the partial spherical surface 21a of the first concave portion 22 is preferably 0.05 μm or more and 1.5 μm or less. The arithmetic mean roughness of the partial spherical surface 21a in the first recess 22 was measured in accordance with the JIS standard (JIS B 0601:2013).

It is preferable that the skewness (Ssk) of the partial spherical surface 21a of the part in which the 1st recessed part 22 and the protrusion part 23 are formed exceeds 0 (it is a positive value). The inclination degree of the partial spherical surface 21a of the part in which the 1st recessed part 22 and the protrusion part 23 were formed was measured according to JIS standard (JIS B 0681-2:2018).

Hereinafter, the manufacturing method of the spherical end mill 100 will be described. FIG. 5 is a step diagram showing a method of manufacturing the spherical end mill 100 . As shown in FIG. 5 , there are preparation step S1 , joining step S2 , and first concave portion forming step S3 .

In the preparation step S1, members constituting the main body portion 10 and the front end portion 20 are prepared. Furthermore, in the preparation step S1, the surface 21 (partial spherical surface 21a) of the front end portion 20 is prepared, and the first concave portion 22 and the protruding portion 23 are not formed. In the joining step S2, the main body portion 10 and the front end portion 20 are joined by, for example, brazing.

In the 1st recessed part formation step S3, the 1st recessed part 22 is formed. The 1st recessed part 22 is formed by irradiating the surface 21 (partial spherical surface 21a) with a laser beam. Since the protruding portions 23 are formed when the ends of the two adjacent first concave portions 22 come into contact with each other, the protruding portions 23 are also formed by forming the first concave portions 22 in the first concave portion forming step S3.

Hereinafter, the effect of the spherical end mill 100 will be described. When the workpiece is machined by the spherical end mill 100, since the coolant is accumulated in the first concave portion 22 (the first concave portion 22 becomes the oil storage portion), the cutting resistance between the flank surface (partial spherical surface 21a) and the workpiece is reduced. , and the cooling effect of the coolant is improved. As a result, the durability of the spherical end mill 100 is improved.

In addition, when the workpiece is machined by the spherical end mill 100, not only the workpiece is cut by the cutting edge 21c, but also the workpiece is ground by the protruding portion 23, so the machining quality of the surface to be machined (specifically, the surface to be machined surface roughness) was improved. In this way, according to the spherical end mill 100, the machining accuracy of the workpiece can be improved.

Since the larger the depth D1 is, the sharper the protruding portion 23 is, so that the machining quality of the surface to be machined is improved. In addition, the larger the depth D1 is, the easier the coolant is to be accumulated in the first concave portion 22 . On the other hand, the larger the depth D1 is, the easier the protrusion 23 is to be broken. Therefore, by setting the depth D1 to be 0.05 μm or more and 20 μm or less, the machining accuracy of the workpiece and the durability of the spherical end mill 100 can be further improved.

The larger the inclination of the partial spherical surface 21a of the part where the first recessed part 22 and the protruding part 23 are formed, the more protruding parts 23 that come into contact with the workpiece. Therefore, if the inclination of the partial spherical surface 21a in the portion where the first recessed portion 22 and the protruding portion 23 are formed exceeds 0, the machining accuracy of the workpiece can be further improved.

The smaller the arithmetic mean roughness of the partial spherical surface 21 a at the first recess 22 is, the less likely the workpiece is to be welded to the first recess 22 . Therefore, the durability of the spherical end mill 100 can be improved by setting the arithmetic mean roughness at the first recessed portion 22 to 0.05 μm or more and 1.5 μm or less.

(Second Embodiment) Hereinafter, the structure of the tool of 2nd Embodiment is demonstrated. The tool of the second embodiment is a machining tool for machining a workpiece. More specifically, the tool of the second embodiment is the spherical end mill 200 . Here, the difference from the configuration of the spherical end mill 100 will be mainly described, and the description will not be repeated.

The spherical end mill 200 has a main body portion 10 and a front end portion 20 . The main body 10 has a handle 11 and a neck 12 . The front end portion 20 has a surface 21 . The surface 21 includes a partial spherical surface 21a. A first concave portion 22 and a protruding portion 23 are formed on the partial spherical surface 21a. In these respects, the configuration of the ball end mill 200 is the same as that of the ball end mill 100 .

FIG. 6 is an enlarged side view of the vicinity of the front end portion 20 of the spherical end mill 200 . As shown in FIG. 6 , in the spherical end mill 200 , the groove 21 b and the cutting edge 21 c are not formed on the surface 21 . That is, in the spherical end mill 200, the surface 21 is constituted by the partial spherical surface 21a. FIG. 7 is a schematic top view of a portion of the spherical surface 21a in the spherical end mill 200. As shown in FIG. FIG. 8 is a cross-sectional view taken along line VIII-VIII of FIG. 7 . As shown in FIGS. 7 and 8 , a second concave portion 24 is further formed on the partial spherical surface 21 a. In these respects, the configuration of the ball end mill 200 differs from that of the ball end mill 100 .

The second concave portion 24 is a concave portion different from the first concave portion 22 . In the second concave portion 24, a part of the spherical surface 21a is concave. The second recessed portion 24 is formed in, for example, the first recessed portion 22 . Let the depth of the 2nd recessed part 24 be the depth D2. The depth D2 is 1 μm or more. The depth D2 is, for example, 20 μm or less.

The equivalent circle diameter of the second concave portion 24 in plan view is preferably 0.5 μm or more and 50 μm or less. The equivalent circle diameter of the second concave portion 24 in plan view is the square root of the value obtained by dividing the area of the second concave portion 24 in plan view by π/4. It is preferable that the area ratio of the 2nd recessed part 24 in the surface 21 is 3% or more and 80% or less. The area ratio of the second concave portion 24 in the surface 21 is a value obtained by dividing the area of the surface 21 on which the second concave portion 24 is formed by the area of the surface 21 on which the first concave portion 22 and the protruding portion 23 are formed.

Hereinafter, the manufacturing method of the spherical end mill 200 will be described. Here, the difference from the manufacturing method of the spherical end mill 100 will be mainly described, and the description will not be repeated.

FIG. 9 is a step diagram showing a method of manufacturing the spherical end mill 200 . As shown in FIG. 9, the manufacturing method of the spherical end mill 200 includes a preparation step S1, a joining step S2, and a first concave portion forming step S3. In this regard, the manufacturing method of the spherical end mill 200 is different from the manufacturing method of the spherical end mill 100 . The manufacturing method of the spherical end mill 200 further includes a second recess forming step S4. In this regard, the manufacturing method of the spherical end mill 200 is different from the manufacturing method of the spherical end mill 100 .

In the 2nd recessed part formation step S4, the formation of the 2nd recessed part 24 is performed. The second recess 24 is formed by, for example, irradiating the surface 21 (partial spherical surface 21 a ) with a laser.

Hereinafter, the effect of the spherical end mill 200 will be described. Here, the difference from the effect of the spherical end mill 100 will be mainly described, and the description will not be repeated.

The spherical end mill 200 does not have the cutting edge 21c. However, the second concave portion 24 functions as a minute cutting edge. Moreover, the 1st recessed part 22 also functions as a cutting edge. On the other hand, when the depth (depth D2) of the second recessed portion 24 is less than 1 μm, the second recessed portion 24 is less likely to function as a cutting edge. In addition, when the depth D2 is less than 1 μm, the second concave portion 24 is blocked by chips generated from the workpiece, and it is likely to become the starting point of welding. As a result, the surface 21 (partial spherical surface 21a) tends to accelerate wear. In this way, according to the spherical end mill 200 having the second concave portion 24 having a depth D2 of 1 μm or more, it is possible to ensure the durability of the tool and to process the workpiece.

If the circle-equivalent diameter of the second concave portion 24 is too large in plan view, the second concave portion 24 cannot easily function as a cutting edge. In addition, when the circle-equivalent diameter of the second concave portion 24 is too small in plan view, the second concave portion 24 is easily clogged by chips. Therefore, by setting the equivalent circle diameter of the second concave portion 24 to be 0.5 μm or more and 50 μm or less in plan view, it is possible to further improve the durability of the tool and to enable workpiece processing.

If the area ratio of the second concave portion 24 is too small, the number of the second concave portion 24 functioning as a cutting edge is small. In addition, if the area ratio of the second concave portion 24 is too large, the ratio of the second concave portion 24 functioning as a cutting edge decreases, and the load per cutting edge (second concave portion 24) increases, so that the surface 21 (partial spherical surface 21a) ) tend to accelerate wear. Therefore, by setting the area ratio of the second concave portion 24 to 3% or more and 80% or less, the durability of the tool can be further improved and the workpiece can be machined.

<Variation example> In the above example, the spherical end mill 200 does not have the groove 21b and the cutting edge 21c, but the spherical end mill 200 may have the groove 21b and the cutting edge 21c.

(third embodiment) Hereinafter, the configuration of the tool of the third embodiment will be described. The tool of the third embodiment is a cutting tool for cutting a workpiece. More specifically, the tool of the third embodiment is the cutting insert 300 .

FIG. 10 is a perspective view of the cutting insert 300 . FIG. 11 is a cross-sectional view of the front end portion 20 of the cutting insert 300 . As shown in FIGS. 10 and 11 , the cutting insert 300 has a base body 30 and a tip portion 20 .

The base body 30 has a first surface 30a, a second surface 30b, and a side surface 30c. The second surface 30b is the opposite surface of the first surface 30a. The side surface 30c is connected to the first surface 30a and the second surface 30b. The base body 30 has a mounting portion 31 . The attachment portion 31 is located at a corner of the base body 30 when viewed from a direction orthogonal to the first surface 30a.

The distance between the first surface 30a and the second surface 30b located in the mounting portion 31 is smaller than the distance between the first surface 30a and the second surface 30b located outside the mounting portion 31 . That is, on the first surface 30 a side of the base body 30 , a level difference is formed in the mounting portion 31 . The base body 30 is formed of cemented carbide, for example.

The front end portion 20 is attached to the attachment portion 31 by brazing or the like. The surface 21 of the front end portion 20 has a cutting surface 21d, a flank surface 21e, and a cutting edge 21f. The cutting surface 21d is connected to the blade flank surface 21e. The cutting surface 21d is connected to the first surface 30a on the opposite side to the belly surface 21e. The belly surface 21e is connected to the side surface 30c on the opposite side to the cutting surface 21d. The cutting edge 21f is formed on the ridgeline between the cutting surface 21d and the flank surface 21e.

The cut surface 21d has a first portion 21da and a second portion 21db. The first portion 21da is a portion of the cutting surface 21d which is connected to the flank surface 21e. The second portion 21db is a portion with the first portion 21da spaced apart from the cutting edge 21f.

The first portion 21da is inclined with respect to the second portion 21db so as to form a negative angle with respect to the second portion 21db. The negative angle formed by the first portion 21da with respect to the second portion 21db refers to the following situation: when the second portion 21db faces upward and the belly surface 21e faces leftward, the first portion 21da is counterclockwise with respect to the second portion 21db rotate. To explain this situation from another viewpoint, the first portion 21da is a negative land (Negative land).

The 1st recessed part 22 and the protrusion part 23 are formed in the cutting surface 21d and the blade surface 21e. More specifically, the 1st recessed part 22 and the protrusion part 23 are formed in the 1st part 21da and the blade edge surface 21e. The 2nd recessed part 24 may be further formed in the cutting surface 21d (1st part 21da) and the blade flank surface 21e.

Hereinafter, the manufacturing method of the cutting insert 300 will be described. FIG. 12 is a step diagram showing a method of manufacturing the cutting insert 300 . As shown in FIG. 12, the manufacturing method of the cutting insert 300 includes a preparation step S1, a joining step S2, a surface forming step S5, and a first recess forming step S3. The manufacturing method of the cutting insert 300 may further have the 2nd recessed part formation step S4.

In the preparation step S1, members constituting the base body 30 and the distal end portion 20 are prepared. In the preparation step S1, the surface 21 of the front end portion 20 is prepared, and the first concave portion 22 and the protruding portion 23 are not formed. In the joining step S2, the base body 30 and the front end portion 20 are joined by, for example, brazing.

In the surface forming step S5 , the cutting surface 21 d and the flank surface 21 e are formed on the surface 21 . The formation of the cutting surface 21d and the formation of the flank surface 21e are performed by, for example, irradiating the surface 21 with a laser. In the surface forming step S5, as a result of forming the cutting surface 21d and the flank surface 21e, the cutting edge 21f is also formed. The first concave portion forming step S3 and the second concave portion forming step S4 are as described above, so the description is omitted here.

Hereinafter, the effect of the cutting insert 300 will be described. When the workpiece is machined by the cutting insert 300, since the coolant is accumulated in the first concave portion 22 (the first concave portion 22 becomes the oil storage portion), the cutting resistance between the surface 21 and the workpiece is reduced, and the cooling effect of the coolant is improved. . As a result, the durability of the cutting insert 300 is improved.

In addition, when the workpiece is machined by the cutting insert 300, the workpiece is not only cut by the cutting edge 21f, but also ground by the protruding portion 23 formed on the flank surface 21e. Therefore, the machining quality of the machined surface (the difference between the workpiece surface and the machined surface) is improved. surface roughness) was improved. In this way, according to the cutting insert 300, the machining accuracy of the workpiece can be improved.

<1st cutting test> In order to confirm the influence of the depth D1 and the inclination of the surface 21 of the part in which the 1st recessed part 22 and the protrusion part 23 were formed, the 1st cutting test was performed. Hereinafter, the first cutting test will be described.

In the first cutting test, samples 1 to 9 were used as the cutting inserts 300 . As shown in Table 1, in samples 1 to 9, the depth D1 changed. Moreover, in the sample 1 - the sample 9, the inclination degree of the surface 21 (1st part 21da and the blade surface 21e) of the part in which the 1st recessed part 22 and the protrusion part 23 were formed was changed. In Samples 1 to 9, the arithmetic mean roughness of the partial spherical surface 21a at the first recess 22 was set to 0.15 μm.

[Table 1] Table 1 Depth D1 (μm) Skewness Ssk Sample 1 0.05 +0.5 Sample 2 0.15 +0.4 Sample 3 1 +0.4 Sample 4 5 +0.4 Sample 5 15 +0.4 Sample 6 20 +0.3 Sample 7 0.03 +0.4 Sample 8 25 +0.4 Sample 9 0.08 -0.3

In the first cutting test, using samples 1 to 9, a round rod-shaped workpiece made of a titanium-6 aluminum-4 vanadium alloy was turned. The first cutting test was carried out under the conditions of a cutting speed of 250 m/min, a conveying amount of 0.2 mm/turn, and a cutting amount of 0.5 mm. In the first cutting test, the coolant was supplied at a pressure of 7 MPa.

The durability (tool life) of the samples 1 to 9 was evaluated based on the time until the abrasion of the blade flank surface 21e reached 150 μm.

Table 2 shows the results of the first cutting test. As shown in Table 2, the tool lives of samples 1 to 6 exceeded the tool lives of samples 7 and 8.

In samples 1 to 6, the depth D1 is in the range of 0.05 μm or more and 20 μm or less, while in samples 7 and 8, the depth D1 is not in the range of 0.05 μm or more and 20 μm or less. Based on this comparison, it has been experimentally confirmed that the durability of the cutting insert 300 can be improved by setting the depth D1 to be 0.05 μm or more and 20 μm or less.

The tool life of samples 1 to 6 exceeded the tool life of sample 9. In Samples 1 to 6, the inclination of the partial spherical surface 21a in the portion where the first recessed portion 22 and the protruding portion 23 are formed exceeds zero. In the sample 9, the inclination of the partial spherical surface 21a of the part in which the 1st recessed part 22 and the protrusion part 23 were formed was less than zero.

Based on this comparison, it has been experimentally confirmed that the durability of the cutting insert 300 can be further improved by setting the inclination of the surface 21 of the portion where the first concave portion 22 and the protruding portion 23 are formed to a positive value.

[Table 2] Table 2 Tool life (minutes) Sample 1 40 Sample 2 45 Sample 3 50 Sample 4 53 Sample 5 62 Sample 6 57 Sample 7 twenty four Sample 8 20 Sample 9 18

<Second cutting test> In order to confirm the influence of the arithmetic mean roughness of the surface 21 (1st part 21da and the blade surface 21e) in the 1st recessed part 22, the 2nd cutting test was performed. Hereinafter, the second cutting test will be described.

In the second cutting test, samples 10 to 14 were used as the cutting inserts 300 . In samples 10 to 14, as shown in Table 3, the arithmetic mean roughness of the surface 21 in the first recess 22 changed. In samples 10 to 14, the depth D1 was set to 15 μm, and the inclination of the surface 21 of the portion where the first concave portion 22 and the protruding portion 23 were formed was set to a positive value.

[table 3] table 3 Arithmetic mean roughness Ra (μm) at the first recess 22 Sample 10 0.05 Sample 11 0.09 Sample 12 0.11 Sample 13 0.15 Sample 14 0.2

The machining conditions of the second cutting test were set to be the same as those of the first cutting test. In the second cutting test, the durability (tool life) of the samples 10 to 14 was evaluated based on the time until the abrasion of the flank surface 21e reached 150 μm.

Table 4 shows the results of the second cutting test. As shown in Table 4, the tool life of samples 10 to 13 exceeded the tool life of sample 14. The arithmetic mean roughness of the partial spherical surface 21a at the first concave portion 22 of the samples 10 to 13 is in the range of 0.05 μm or more and 1.5 μm or less. On the other hand, the arithmetic mean roughness of the partial spherical surface 21a in the first concave portion 22 of the sample 14 is not within the range of 0.05 μm or more and 1.5 μm or less.

Based on this comparison, it has been experimentally confirmed that the durability of the cutting insert 300 can be improved by setting the arithmetic mean roughness of the partial spherical surface 21a at the first recess 22 to 0.05 μm or more and 1.5 μm or less.

[Table 4] Table 4 Tool life (minutes) Sample 10 52 Sample 11 70 Sample 12 59 Sample 13 62 Sample 14 38

<The third cutting test> In order to confirm the influence of the depth (depth D2) of the 2nd recessed part 24, the equivalent circle diameter of the 2nd recessed part 24 in plan view, and the area ratio of the 2nd recessed part 24, the 3rd cutting test was performed. Hereinafter, the third cutting test will be described.

In the third cutting test, samples 15 to 25 were used as the cutting inserts 300 . In Samples 15 to 25, as shown in Table 5, the depth D2, the equivalent circle diameter of the second recessed portion 24 in plan view, and the area ratio of the second recessed portion 24 were changed. In samples 15 to 25, the depth D1 was set to 15 μm, the inclination of the surface 21 of the portion where the first concave portion 22 and the protruding portion 23 were formed was set to a positive value, and the surface 21 of the first concave portion 22 was The arithmetic mean roughness was set to 0.15 μm.

[table 5] table 5 Depth D2 (μm) Equivalent circle diameter (μm) of the second recess 24 Area ratio (%) of the second recess 24 Sample 15 1.1 0.5 55 Sample 16 3 8 48 Sample 17 5 25 58 Sample 18 8 50 48 Sample 19 7 7 3.1 Sample 20 6 5 79 Sample 21 0.4 1 51 Sample 22 1.2 0.2 45 Sample 23 10 60 47 Sample 24 7 8 1.2 Sample 25 7 8 85

The machining conditions of the third cutting test were set to be the same as those of the first cutting test. In the third cutting test, the durability (tool life) of the samples 15 to 25 was evaluated based on the time until the abrasion of the flank surface 21e reached 150 μm. The results of the third cutting test are shown in Table 6.

[Table 6] Table 6 Tool life (minutes) Sample 15 92 Sample 16 101 Sample 17 115 Sample 18 110 Sample 19 103 Sample 20 95 Sample 21 65 Sample 22 58 Sample 23 70 Sample 24 67 Sample 25 55

The tool life of samples 15 to 20 exceeded the tool life of sample 21. The depth D2 of the samples 15 to 20 is in the range of 1 μm or more. On the other hand, the depth D2 of the sample 21 is not in the range of 1 μm or more. According to this comparison, it has been experimentally confirmed that the tool life of the cutting insert 300 is improved by setting the depth D2 to be 1 μm or more.

The tool lives of samples 15 to 20 exceeded the tool lives of samples 22 and 23. The equivalent circle diameters of the second recesses 24 of the samples 15 to 20 are in the range of 0.5 μm or more and 50 μm or less. On the other hand, the equivalent circle diameters of the second recesses 24 of the samples 22 and 23 are not within the range of 0.5 μm or more and 50 μm or less. Based on this comparison, it has been experimentally confirmed that the tool life of the cutting insert 300 is improved by setting the equivalent circle diameter of the second recess 24 in plan view to 0.5 μm or more and 50 μm or less.

The tool lives of samples 15 to 20 exceeded the tool lives of samples 24 and 25. The area ratio of the 2nd recessed part 24 in the surface 21 of the sample 15 - the sample 20 is in the range of 3% or more and 80% or less. On the other hand, the area ratio of the 2nd recessed part 24 in the surface 21 of the sample 22 and the sample 23 is not in the range of 3% or more and 80% or less. According to this comparison, it has been experimentally confirmed that the tool life of the cutting insert 300 is improved by setting the area ratio of the second concave portion 24 in the surface 21 to 3% or more and 80% or less.

<Variation example> The contents of the first to third embodiments described above can also be applied to cutting tools other than the cutting insert 300 . FIG. 13 is a side view of the radius end mill 400 . The content of the above-described third embodiment can be applied to, for example, a radial end mill 400 shown in FIG. 13 . More specifically, the first concave portion 22 and the protruding portion 23 are formed on the flank surface and the cutting surface formed on the distal end portion 20 of the radial end mill 400 .

(fourth embodiment) Hereinafter, the configuration of the tool of the fourth embodiment will be described. The tool of the fourth embodiment is a measuring tool for measuring the surface roughness or shape of a workpiece. More specifically, the tool of the fourth embodiment is a probe 500 .

FIG. 14 is a side view of the probe 500 . As shown in FIG. 14 , the probe 500 has the front end portion 20 . The probe 500 scans the workpiece in such a manner that the surface 21 is in contact with the surface of the workpiece. Thereby, the surface roughness or shape of the workpiece is measured. A first recessed portion 22 and a protruding portion 23 are formed on the surface 21 . On the surface 21, the 2nd recessed part 24 may be further formed.

Hereinafter, the effect of the probe 500 will be described. Since the first concave portion 22 and the protruding portion 23 are formed on the surface 21, the contact resistance between the surface of the workpiece and the surface 21 when the probe 500 is scanned can be reduced.

It should be considered that all the contents of the embodiments disclosed this time are illustrative and not restrictive of the present invention. The scope of the present invention is indicated not by the above-described embodiments but by the scope of claims, and is intended to include the meaning equivalent to the scope of claims and all modifications within the scope.

10: Main body 10a: End 1 10b: End 2 11: handle 11a: end 1 11b: End 2 12: Neck 12a: end 1 12b: End 2 13: Connection layer 20: Front end 21: Surface 21a: Partial spherical surface 21b: Slot 21c: Cutting edge 21d: Cutting face 21da: Part 1 21db: Part 2 21e: belly of the knife 21f: Cutting edge 22: 1st recess 23: Protrusions 24: 2nd recess 30: Matrix 30a: Side 1 30b: Side 2 30c: side 31: Installation Department 100: Ball end mill 200: Ball end mill 300: Cutting inserts 400: Radius end mill 500: Probe A: Rotary axis D1, D2: depth R: diameter S1: Preparation steps S2: Joining step S3: 1st recess forming step S4: Second recess forming step S5: face forming step

FIG. 1 is a side view of a ball end mill 100 . FIG. 2 is an enlarged view of area II of FIG. 1 . FIG. 3 is a schematic top view of a portion of the spherical surface 21 a in the spherical end mill 100 . FIG. 4 is a cross-sectional view taken along line IV-IV of FIG. 3 . FIG. 5 is a step diagram showing a method of manufacturing the spherical end mill 100 . FIG. 6 is an enlarged side view of the vicinity of the front end portion 20 of the spherical end mill 200 . FIG. 7 is a schematic top view of a portion of the spherical surface 21a in the spherical end mill 200. As shown in FIG. FIG. 8 is a cross-sectional view taken along line VIII-VIII of FIG. 7 . FIG. 9 is a step diagram showing a method of manufacturing the spherical end mill 200 . FIG. 10 is a perspective view of the cutting insert 300 . FIG. 11 is a cross-sectional view of the front end portion 20 of the cutting insert 300 . FIG. 12 is a step diagram showing a method of manufacturing the cutting insert 300 . FIG. 13 is a side view of radius end mill 400 . FIG. 14 is a side view of a stylus 500. FIG.

22: 1st recess

23: Protrusions

Claims (14)

A tool having a front end formed from binderless cubic boron nitride, The above-mentioned front end portion has a surface in contact with the workpiece, At least a part of the said surface contains a some 1st recessed part, and the protrusion part formed by the mutual contact of the edge of two adjacent said 1st recessed part. The tool of claim 1, wherein the tool is a measuring tool for measuring the surface roughness or shape of the workpiece. The tool of claim 1, wherein the above-mentioned tool is a processing tool for processing the above-mentioned workpiece. The tool of claim 3, wherein said surface comprises a partial spherical surface. The tool of claim 4, wherein the surface includes a groove, and a cutting edge formed at the ridgeline of the groove and the partial spherical surface. The tool of claim 1, wherein said tool is a cutting tool for cutting said workpiece, The surface includes a cutting surface, a flank surface connected to the cutting surface, and a cutting edge formed at the edge of the cutting surface and the flank surface. The tool according to claim 3, wherein the depth of the first recess is 0.05 μm or more and 20 μm or less. The tool according to claim 3, wherein the arithmetic mean roughness of the surface of the first recess is 0.05 μm or more and 1.5 μm or less. The tool according to claim 3, wherein the deflection parameter of the surface portion on which the first concave portion and the protruding portion are formed exceeds 0. The tool of any one of claims 3 to 9, wherein at least a portion of said surface includes a second recess that is different from said first recess, The depth of the said second recessed part is 1 micrometer or more. The tool according to claim 10, wherein the equivalent circle diameter of the second recessed portion in plan view is 0.5 μm or more and 50 μm or less. The tool of claim 10, wherein the area ratio of the second recess in the surface is 3% or more and 80% or less. A method of manufacturing a tool, comprising the steps of: preparing a front end portion to be formed from binderless cubic boron nitride; and By irradiating a laser, a plurality of first recesses are formed on at least a part of the surface of the front end portion; and A protrusion is formed in a part of the surface of the said front-end|tip part by the end of two adjacent said 1st recessed parts contacting. The method of manufacturing a tool according to claim 13, further comprising the steps of forming a cutting surface on the surface of the front end portion by irradiating a laser, and a flank surface connected to the cutting surface.

Images