JP2002254232A - Cutting method by rotary tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cutting method which enables a cutting operation with high precision for a short length of time. SOLUTION: The cutting method is for forming in a material 6 a concave part W whose at least one part is constituted of a curved surface. Following processes are characteristically repeated until the concave part is formed in the material 6; the process that numeric data for forming the concave part is divided into numeric data for each of a plurality of concave parts zones by contours; the process that a border groove is cut with a first rotary tool; the process that an area surrounded by the border groove cut in the preceding process is cut with a larger second rotary tool 240c than the first rotary tool; the process that a border groove is cut at the bottom of the concave part formed in the preceding process with the first rotary tool; the process that the area surrounded by the border groove cut in the preceding process is cut with the second rotary tool.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cutting method, and more particularly to a cutting method for forming a concave portion, a convex portion and the like including a curved surface on a material by a cutting process using a rotary blade.

[0002]

2. Description of the Related Art A method of forming a concave portion, a convex portion, or the like in a material such as a material by cutting is performed by rotating a cutting tool such as a drill or an end mill with a so-called spindle unit to cut the material to obtain a concave portion having a desired shape. There is a method of forming convex portions and the like.

[0003] In particular, when forming concave and convex portions having fine irregularities like a molding die, machining by electric discharge machining is also performed.

[0004]

In a cutting method for forming a concave portion, a convex portion and the like by cutting using a spindle unit as described above, if a thin drill or a mill is used in order to increase the processing accuracy, it takes a unit time. Since the amount of cutting per unit area is small, a long working time is required until the concave portions, convex portions, and the like are completed. On the other hand, if a tool having a large cutting portion with a large cutting amount is used, fine processing cannot be performed on a concave portion, a convex portion, or the like. For this reason, for example, in the concave portion for the mold cavity, the concave portion is roughly cut and formed with a thick cutting portion, and then the intermediate finish processing of the surface of the concave portion is performed with a tool having a cutting portion of an intermediate thickness. ,Finally,
The final finishing of the surface of the concave portion is performed with a tool having a cutting portion for fine finishing.

[0005] Further, in the electric discharge machining, it takes time and cost to prepare an electrode for electric discharge machining, and it is difficult to machine a machining portion located at the back of the concave portion.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and has as its basic object to provide a cutting method capable of performing high-precision cutting in a short working time.

[0007]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides a method for forming a concave portion at least partially formed of a curved surface in a material. This method
(A) dividing the numerical data of the concave portion to be formed into numerical data for each of a plurality of concave portions having different height positions vertically defined by contour lines divided by a predetermined height difference; Based on the numerical data for each part, using the first elongated rotary tool having cutting edges formed at the tip and side surfaces, along the contour line that defines the highest concave portion, inside the contour line, Cutting a contour groove having a depth equal to the thickness of the portion; and (c) using a second rotary tool thicker than the first rotary tool based on the numerical data for each of the concave portions, Cutting the region surrounded by the contour groove cut in the above step to form the highest concave portion on the surface of the material in a shape having a flat bottom, and (d) numerical data for each of the concave portions Based on the first step, using the first rotary tool A contour groove having a depth equal to the thickness of the concave portion inside the contour line along the contour line that defines the concave portion having the height next to the concave portion formed in the previous step on the bottom surface of the formed concave portion. A step of cutting, and (e) cutting, using the second rotary tool, a region surrounded by the contour groove cut in the previous step based on the numerical data for each of the concave portions, and Forming a new concave portion having a continuous and flat bottom surface under the existing concave portion, and (f) repeating (d) and (e) until the concave portion is formed in the material. Become.

According to such a configuration, the surface of the concave portion is
Since it is cut by a thin rotating blade, fine processing becomes possible, and the processing accuracy is also improved.
In some cases, finishing is not required.

Further, the present invention provides a method for forming a convex portion having a curved surface at least in part on a material.
This method comprises the steps of: (a) dividing numerical data of a concave portion surrounding a convex portion to be formed into numerical data for each of a plurality of concave portions having different heights up and down, which are divided by contour lines divided by a predetermined height difference. (B) an elongated first cutting edge formed on the tip and side surfaces based on the numerical data for each concave portion;
Cutting a contour groove having a depth equal to the thickness of the highest concave portion inside the contour line along a contour line defining the highest concave portion, using the rotary tool of (c), On the basis of the numerical data of each part, a region outside the contour groove cut in the previous process is cut using a second rotary tool thicker than the first rotary tool, and the highest concave portion is flattened. Forming on the surface of the material into a shape having a bottom, and (d) forming the first
Using the rotating tool, the bottom of the concave portion formed in the previous step, along the contour line that separates the concave portion of the height next to the concave portion formed in the previous step, inside the contour line of the concave portion Cutting a contour groove having a depth equal to the thickness,
(E) Based on the numerical data for each of the concave portions, the second rotary tool is used to cut an area outside the contour groove cut in the previous process, and to cut the region below the already formed concave portion. Forming a new concave portion having a continuous and flat bottom surface,
(F) repeating steps (d) and (e) until the recess is formed in the material.

[0010] Even with such a configuration, since the surface of the convex portion is cut by a thin rotary blade, fine processing can be performed, processing accuracy can be improved, and in some cases, finishing processing can be performed. Becomes unnecessary.

In one aspect of the present invention, prior to cutting the contour groove by the first rotary tool, the guide groove along the cutting line on which the contour groove is to be formed is formed by the first rotating tool. It is formed by a rotating tool. According to such a configuration, the guide groove is formed at a more accurate position.

In one aspect of the present invention, the guide groove is formed by moving the first rotary tool a plurality of times along a cutting line.

In one embodiment of the present invention, the predetermined height difference is 3 μm to 50 μm. Further, in one aspect of the present invention, the first rotary tool includes a cutting blade at a tip and a side surface, a diameter D is 1 mm or less, and a ratio L / D between the effective length L and the diameter D is 10 or more. A cutting tool having an elongated cylindrical cutting portion.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. First, a schematic configuration of a numerical control type cutting machine (machining center) for performing a cutting method according to an embodiment of the present invention will be described.

FIG. 1 is a schematic perspective view of the machining center 1. As shown in FIG. 1, the machining center 1 includes a base 2 installed on a floor, and a processing unit 4 disposed above the base 2. A processing table 8 on which a workpiece (work) 6 to be cut is placed is provided below the processing section 4. The processing table 8 is formed by a known mechanism based on numerical data for cutting.
It is configured to be able to move vertically and horizontally.

A head 10 is provided above the processing table 8, and a unit mounting portion 14 to which the spindle unit 12 is removably mounted is provided below the head 10. In the spindle unit 12, the cutting tool 16 attached to the tip faces the processing table 8 and the processing table 8
The upper work 6 is mounted on the unit mounting portion 12 so that the upper work 6 can be cut. The head 10 can be moved in the vertical and horizontal directions with respect to the processing table 8 by a known mechanism based on numerical data for cutting.

A chuck is built in the unit mounting section 14, and a coupler (not shown) at the rear end of the spindle unit 12 is coupled to the chuck so that the spindle unit 12 is removably mounted and fixed to the unit mounting section 14. can do. This spindle unit 12
Is a cutting tool 16 attached to the tip of a rotatable spindle.
Can be rotated at a high speed of 50,000 rpm or more by a built-in motor to cut the work 6.

Therefore, in the machining center 1, the worktable 6 on which the work 6 is mounted and the spindle unit 12 are relatively moved based on numerical data related to the cut work, thereby cutting the work 6 as desired. be able to.

The machining center 1 is a so-called ATC capable of automatically replacing the spindle unit 12.
(Automatic tool changer). As shown in FIG. 1, on the side of the head 10, there is provided a replacement spindle unit mounting portion 18 on which a replacement spindle unit is mounted. A plurality of replacement spindle units 20 to which cutting tools having different dimensions and shapes are attached are mounted.

Under the head 10, a replacement arm 2 for replacing the spindle unit 12 mounted on the unit mounting section 14 with a replacement spindle unit 20 mounted on the replacement spindle unit mounting section 18 is provided.
2 are provided. In this embodiment, the replacement spindle unit mounting section 18 connects the replacement spindle unit 20 to the replacement arm 22 by a drive mechanism (not shown).
Direction, and the desired replacement spindle unit 20 is gripped by the replacement arm 22.
The spindle unit 12 is configured to be exchangeable with the spindle unit 12 mounted on the spindle unit 4. Therefore, in the machining center 1, various processes can be performed on the workpiece 6 by replacing the spindle unit 12 mounted on the unit mounting section 14.

In this embodiment, the cutting tool 16 which is a rotary tool mounted on the spindle unit mounted on the unit mounting portion or the plurality of replacement spindle units 20 is integrated with the main shaft connected to the built-in motor output shaft. Has been As the type of the cutting tool 16, a so-called ball end mill 24 (FIG. 2) having a substantially hemispherical convex tip, a so-called flat end mill 26 (FIG. 3) having a flat tip is provided. Is a conical mill 28 (FIG. 4). A plurality of types of ball end mills 24, flat end mills 26, and mills 28 having different thicknesses (diameters) of cutting portions are mounted on the plurality of replacement spindle units 20, respectively. Each of these mills 24, 26, 28 has a tip 24a,
Cutting blades are provided on 6a, 28a and side surfaces 24b, 26b, 28b. These mills include a thin mill having a slender cylindrical cutting portion having a diameter D of 1 mm or less and a ratio L / D of the effective length L to the diameter D of 10 or more, that is, a mill having a small diameter of the cutting portion. , Thick mills with larger diameters than thin mills.

Next, referring to FIGS. 5 to 13, the metal material for the mold (work 6) is provided with, for example, a concave portion which becomes a cavity of a mold for manufacturing a cellular phone component. The formation of the concave portion by the cutting method according to the embodiment will be described. Generally, as a metal material for a mold, for example, a rolled steel material for general structure (SS), a carbon steel for machine structure (SC, S
CK), carbon tool steel (SK), alloy tool steel (SKS, S
KD), high speed steel (SNC), high carbon chromium, bearing steel (SNJ), nickel chrome molybdenum steel (SNC)
M), chromium molybdenum steel (SCM), aluminum chromium molybdenum steel (SACM), pre-hardened steel, high-strength aluminum alloy, aluminum alloy such as duralumin (A7075), copper alloy and the like.

First, numerical data of a concave portion to be formed, which is generated based on design digital data created by three-dimensional CAD, is divided into upper and lower heights defined by contour lines divided by a predetermined height difference. It is divided into numerical data for each of a plurality of concave portions. Specifically, the concave portion W formed by the dotted line in FIG. 5 is horizontally divided at predetermined intervals on the numerical data as shown in FIG. 5 and FIG. Numerical data corresponding to each of the concave portions W1 to Wn is generated as the concave portions W1 to Wn. The above-mentioned predetermined interval, which is the thickness of each concave portion, is set in consideration of conditions such as the diameter of the cutting tool used for cutting the contour groove, the shape of the concave portion to be processed, and the like. For example, if the diameter of the tool used is 0.2
3 mm when the diameter is extremely thin, and up to 50 mm when the diameter of the tool to be used is relatively thick, 1 mm.
It is set to about μm. In the drawings, the thickness of each concave portion is extremely large with respect to the dimension of the work 6 for clarity.

This step may be performed by an external computer for generating numerical data of the concave portion, an external or built-in computer for controlling the machining center, or another computer.

Next, or simultaneously with or before this, a thin mill, in this embodiment, the diameter D is 0.4 m
The spindle unit 12 to which the ball end mill 24 having an effective length L of 10 mm is attached
Aluminum alloy (A7075) to be mounted on and machined
The work 6 is placed and fixed on the processing table 4.

Next, the ball end mill 24 is driven, for example, at 500
Based on the numerical data of the concave portion W1 at the highest position, the ball end mill 24, which is the first elongated rotary tool having a cutting blade formed on the tip and the side, is rotated by rotating the ball end mill 24 at the highest position. A guide groove g1 is formed along a contour line R1 that defines the high concave portion W1 (FIG. 7). The depth of the guide groove g1 is smaller than the thickness of the concave portion W1.

The "contour line defining the concave portion" is a contour line drawn at a position where the boundary between the concave portion and the concave portion located immediately above the concave portion intersects the contour surface of the concave portion. Therefore,
Contour line R1 that defines the concave portion W1 at the highest position
Corresponds to the contour of the concave portion on the surface of the workpiece 6 and 2
The contour line R2 defining the second concave portion W2 is a contour line drawn at a position where the boundary surface between the highest concave portion W1 and the second concave portion W2 intersects the contour surface of the concave portion.

Next, the cutting part 2 of the ball end mill 24
4c is moved along the guide groove g1 while, for example, rotating at 50,000 rpm or more, so that the highest concave portion W in the cutting portion 24c of the ball end mill 24 is obtained.
A vertical contour groove G1 having a depth equal to the thickness of No. 1 is cut (FIGS. 7 and 8). Guide groove g1 and contour groove G1
Is formed on the basis of the numerical data of the highest concave portion W1, the inside of the contour line R1 where the cutting portion 24c of the ball end mill 24 partitions the highest concave portion W1 is defined by the contour line R1.
This is performed by relatively moving the worktable 4 on which the work 6 is placed and the spindle unit 12 so as to move along. Therefore, the formed contour groove G1 is
It is inscribed in the contour line R1.

Next, the spindle unit 12 mounted on the spindle unit mounting section 14 is moved to a cutting section 240c thicker than the ball end mill 24 used for cutting the groove.
Is replaced with the spindle unit 20 on which the ball end mill having the above is mounted.

Then, based on the numerical data of the uppermost concave portion W1, a region surrounded by the contour groove G1 is cut using a thick ball end mill, and the highest concave portion W1 is formed into a shape having a flat bottom. It is formed on the surface of the work 6 (FIG. 9).
In this cutting, the cutting portion 240c of the ball end mill moves in the area surrounded by the contour groove G1 to cut and remove the metal material in the area surrounded by the contour groove G1, based on the numerical data of the highest concave portion W1. The processing is performed by relatively moving the worktable 4 on which the work 6 is placed and the spindle unit 12. In the present embodiment, the cutting portion 240c of the thick ball end mill moves within the region surrounded by the contour groove G1 along the path P indicated by the dashed line in FIG. All of the metal material is removed by cutting to form the uppermost concave portion W1 having a flat bottom (FIG. 10).

Next, the spindle unit 12 mounted on the spindle unit mounting portion 14 is moved to the guide groove g1.
And ball end mill 2 used for cutting contour groove G1
4 (first rotary tool), and the cutting portion 24c of the ball end mill 24 is rotated at, for example, 50,000 rpm or more, so that the bottom portion of the uppermost concave portion W1 which is the concave portion formed in the previous step is formed. Along the contour line (ie, inscribed in the contour line) inside the contour line that defines the second concave portion W2 located at the height position next to the uppermost concave portion W1.
A guide groove g2 is formed (FIG. 11).

Next, the cutting portion 2 of the ball end mill 24
4c is moved along the guide groove g2 while rotating at a speed of 50,000 rpm or more, so that the cutting portion 24c of the ball end mill 24 has a vertical contour groove G2 having a depth equal to the thickness of the concave portion W2. To cut. The formation of the guide groove (g2) and the contour groove (G2) is based on the numerical data of the second concave portion W2 based on the ball end mill 24.
Is performed by relatively moving the worktable 4 on which the work 6 is mounted and the spindle unit 12 so that the cutting portion 24c moves along the contour line defining the second concave portion W2.

Again, the spindle unit 12 mounted on the spindle unit mounting portion 14 is replaced with a spindle unit 20 having a ball end mill having a cutting portion 240c thicker than the ball end mill 24 used for cutting the groove. Based on the numerical data of the second concave portion W2, a region surrounded by the contour groove G2 is cut using a thick ball end mill (FIG. 12).
2 is formed below the uppermost concave portion W1 into a shape having a flat bottom. This cutting is performed based on the numerical data of the second concave portion W2 in the same manner as when cutting the uppermost concave portion W1.
The worktable 4 on which the work 6 is placed and the spindle are so arranged that the cutting portion 240c of the ball end mill moves in the region surrounded by the contour groove G2 to cut and remove the metal material in the region surrounded by the contour groove G2. This is performed by relatively moving the unit 12. In the present embodiment, the cutting portion 240 of the ball end mill is also cut along the path P as indicated by a dashed line in FIG.
c moves in the region surrounded by the contour groove G2, and all the metal material in the region surrounded by the contour groove G2 is cut and removed, thereby forming the second concave portion W2 having a flat bottom.

A guide groove g and a contour groove G are cut and formed by the thin cutting portion 24c for each concave portion W, and thereafter, a metal material in a region surrounded by the contour groove G is removed by the thick cutting portion 240C. This is repeated until the lowermost concave portion Wn is cut and formed to complete the concave portion W (FIG. 13).

The inner surface of the recess W formed in this manner is microscopically constituted by a minute step-like shape whose height is the thickness of the recess. By setting it very small with respect to the dimension of W, this inner surface becomes a substantially smooth curved surface. Therefore, the height (thickness) of the concave portion is changed according to the accuracy of the inner surface required for the concave portion.

In the above embodiment, since the entire contour of the concave portion W is cut by the cut portion 24c having a small diameter, the concave portion W requires fine processing such as a thin cut portion K shown in FIG. Even in the case of having a portion, it is possible to machine a portion requiring such fine machining with high accuracy without changing tools.

Next, as shown in FIG. 14 to FIG. 16, for example, a convex portion forming a cavity of a mold for manufacturing a cellular phone component is formed in the metal material (work 6) for the mold. The formation of the projections by the cutting method according to the second embodiment of the present invention will be described. In the present embodiment, the concave portion W, which is a space, surrounds the convex portion P.

In the present embodiment, the object to be formed is a convex portion. The metal material located in the space (concave portion) W around the convex portion P to be formed is gradually removed by a rotary tool by cutting. Therefore, except that the guide groove g and the contour groove G are formed so as to circumscribe the contour line R, and that the metal material outside the contour groove is removed, basically the first embodiment is different from the first embodiment. It has the same configuration as the recess formation.

That is, numerical data of a portion (recess) to be removed is calculated from data of a convex portion to be formed, which is generated based on design digital data created by three-dimensional CAD, and the numerical data of the concave portion is calculated. Numerical data is divided into a plurality of concave portions having different height positions in the upper and lower areas defined by contour lines divided by a predetermined difference in height. Then, a thin mill, in this embodiment, the diameter D is 0.4 mm, the effective length L
The spindle unit 12 to which the ball end mill 24 of 10 mm is attached is mounted on the unit mounting portion 14,
A work 6 to be cut is placed and fixed on the worktable 4.

Next, the ball end mill 24 is driven, for example, at 500
Based on the numerical data of the concave portion W1 at the highest position, the ball end mill 24, which is the first elongated rotary tool having a cutting blade formed on the tip and the side, is rotated by rotating the ball end mill 24 at the highest position. A guide groove g1 is formed along a contour line that defines the high concave portion W1. Next, by moving the cutting portion 24c of the ball end mill 24 along the guide groove g1 while rotating the cutting portion 24c at 50,000 rpm or more, the thickness of the cutting portion 24c of the ball end mill 24 is equal to the thickness of the highest concave portion W1. A vertical contour groove G1 having a depth is cut (FIGS. 14 and 15).

The formation of the guide groove g1 and the contour groove G1 is based on the numerical data of the highest concave portion W1, and the cutting portion 24c of the ball end mill 24 moves the outer side of the contour line defining the highest concave portion W1 along this contour line. The worktable 4 on which the work 6 is mounted and the spindle unit 12
This is performed by relatively moving. Therefore, the formed contour groove G1 circumscribes the contour line R1.

Next, the spindle unit 12 mounted on the spindle unit mounting portion 14 is replaced with a spindle unit 20 having a ball end mill having a cutting portion 240c thicker than the ball end mill 24 used for cutting the groove, and On the basis of the numerical data of the uppermost concave portion W1, a region outside the contour groove G1 is cut using a thick ball end mill to obtain the highest concave portion W1.
Is formed on the surface of the work 6 into a shape having a flat bottom (FIG. 16). This cutting is performed based on the numerical data of the highest concave portion W1 based on the cutting portion 240c of the ball end mill.
Moves the processing table 4 on which the work 6 is mounted and the spindle unit 12 relatively so that the workpiece moves in a region outside the contour groove G1 and cuts and removes an area surrounded by the contour groove G1. Be executed.

In the present embodiment, similarly to the first embodiment, a guide groove g and a contour groove G are formed in each concave portion W by a thin cutting portion 24c, and then a thick cutting portion 240 is formed. The step of removing the metal material in the region outside the contour groove G is repeated until the lowermost concave portion Wn is formed by cutting and the concave portion W is completed.

The outer surface of the protrusion P formed in this manner has a microscopic shape formed by minute steps whose height is equal to the thickness of the recess. Is set to be extremely small with respect to the size of the projection,
This surface is a substantially smooth curved surface. Therefore, the height (thickness) of the concave portion is changed according to the accuracy of the surface required for the convex portion.

According to the first and second embodiments, since the surface of the concave portion W or the convex portion P is constituted by the wall of the contour groove cut by the cutting portion having a small diameter, Even when W is used, for example, as a mold cavity, finishing is not required. Also,
The removal of the metal material in the region surrounded by the contour groove (first embodiment) or the region outside the contour groove (second embodiment)
Since the removal is performed by a thick rotary tool having a large amount of cutting, the removal can be completed in a short time, and the time required for forming the concave portion or the convex portion is reduced.

The present invention is not limited to the above embodiment. In the above embodiment, all the concave portions have the same thickness, but the thickness of each concave portion (the difference in predetermined height) is changed according to the inclination of the inner surface of the concave portion (or the surface of the convex portion) formed by the concave portion. For example, the thickness may be increased in a portion having a large inclination, and the thickness may be decreased in a portion having a small inclination.

In the above embodiment, the machining center 1 in which the spindle unit can be automatically replaced is used. However, the present invention can be implemented in a cutting machine in which the spindle unit cannot be replaced automatically or cannot be replaced. It is. In such a cutting machine, an operator manually replaces the entire spindle unit or a cutting tool (mill) in order to perform cutting with a mill having cutting portions of different diameters.

In the above embodiment, a ball end mill is used as a cutting tool. However, other types of mills such as a flat end mill (FIG. 3) or other rotating tools are used to form grooves. Formation or removal of a portion surrounded by the groove or an outer portion of the groove may be performed.

In the above embodiment, the cutting tool is set at 5
Although the guide groove and the contour groove are formed by rotating at 0000 or more rotations, the present invention is not limited to this number of rotations. For example, the rotation is 30000 rotations or more per minute or less. It can be a number.

Further, the above embodiment is a cutting process for forming a concave portion in a metal material, but the present invention can also be applied to a case where another type of material is cut.

In the above embodiment, the guide groove and the contour groove are formed by the same mill in all the concave portions, but the mill used may be changed depending on the concave portion.

Further, the above-mentioned predetermined interval, which is the thickness of each concave portion, may be set to be substantially the same as the cutting depth (depth) that can be cut by a cutting tool to be used at one time, or may be set to a value larger than this. May be. If the value is set to a value larger than the depth of cut (depth), when cutting a certain concave portion, the cutting tool is moved along the cutting path multiple times by changing the position in the vertical (Z) direction. By the movement, the cutting of the guide groove or the contour groove and the cutting of the area surrounded by the contour groove or outside the contour groove are performed.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view of a machining center that performs cutting according to an embodiment of the present invention.

FIG. 2 is a side view of a ball end mill used for cutting according to the embodiment of the present invention.

FIG. 3 is a side view of a flat end mill used for cutting according to the embodiment of the present invention.

FIG. 4 is a side view of a mill having a substantially triangular tip at a cutting portion used for cutting according to the embodiment of the present invention.

FIG. 5 is a cross-sectional view illustrating a process of dividing the concave portion for forming the concave portion into the concave portion according to the first embodiment of the present invention.

FIG. 6 is a perspective view illustrating a process of dividing the concave portion for forming the concave portion into the concave portion according to the first embodiment of the present invention.

FIG. 7 is a perspective view illustrating a contour groove for the uppermost concave portion in the first embodiment of the present invention.

FIG. 8 is a cross-sectional view illustrating cutting of a contour groove for the uppermost concave portion in the first embodiment of the present invention.

FIG. 9 is a perspective view illustrating cutting of a region surrounded by a contour groove for the uppermost concave portion in the first embodiment of the present invention.

FIG. 10 is a perspective view showing an uppermost concave portion formed by cutting in the first embodiment of the present invention.

FIG. 11 is a perspective view illustrating cutting of a contour groove corresponding to a second concave portion in the first embodiment of the present invention.

FIG. 12 is a perspective view illustrating cutting of a region surrounded by a contour groove for a second concave portion in the first embodiment of the present invention.

FIG. 13 is a perspective view of a recess formed by cutting in the first embodiment of the present invention.

FIG. 14 is a cross-sectional view illustrating a contour groove for the uppermost concave portion in the second embodiment of the present invention.

FIG. 15 is a perspective view for explaining the contour groove cutting of the uppermost concave portion in the second embodiment of the present invention.

FIG. 16 is a perspective view illustrating cutting of an outer region of a contour groove for the uppermost concave portion in the second embodiment of the present invention.

[Explanation of symbols]

 6: Workpiece (workpiece) 24c: (thin) cutting portion 240c: (thick) cutting portion g: guide groove G: contour groove R: contour line W: concave portion W1 to Wn: concave portion

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Shinichi Abe 3-2-1 Sakado, Takatsu-ku, Kawasaki-shi, Kanagawa Inks Inc. (72) Inventor Takashi Inomata 3-2- Sakado, Takatsu-ku, Kawasaki-shi, Kanagawa 1 Inc. Inc. (72) Naoki Horiguchi, Inventor 3-2-1 Sakado, Takatsu-ku, Kawasaki, Kanagawa Prefecture Ink Inc. (72) Kazuyasu Suda 3-2-1, Sakado, Takatsu-ku, Kawasaki, Kanagawa Prefecture Inks Inc. (72) Inventor Jun Nishijima 3-2-1 Sakado, Takatsu-ku, Kawasaki-shi, Kanagawa F-term in Inks Inc. (reference) 3C022 EE17 5H269 AB05 AB19 AB31 CC02 DD01 QA01

Claims (6)

[Claims] 1. A cutting method for forming a concave portion having at least a part of a curved surface in a material, comprising: (a) dividing numerical data of a concave portion to be formed by contour lines divided by a predetermined height difference; Dividing the numerical data for each of a plurality of concave portions having different heights up and down; and (b) an elongated first rotary tool having cutting edges formed at the tip and side surfaces based on the numerical data for each concave portion. Using,
Cutting a contour groove having a depth equal to the thickness of the highest concave portion inside the contour line along the contour line defining the highest concave portion; and (c) cutting the numerical data for each of the concave portions. Based on the above, the area surrounded by the contour groove cut in the previous step is cut using a second rotary tool thicker than the first rotary tool, and the highest concave portion is formed into a shape having a flat bottom. Forming on the surface of the material, (d) using the first rotating tool, based on the numerical data for each of the concave portions, on the bottom surface of the concave portion formed in the previous process,
(E) cutting a contour groove having a depth equal to the thickness of the concave portion inside the contour line along a contour line defining a concave portion having a height next to the concave portion formed in the previous step; Based on the numerical data for each concave portion, using the second rotary tool, cut the area surrounded by the contour groove cut in the previous process, and continuously cut under the already formed concave portion. Forming a new concave portion having a flat bottom surface; and (f) repeating steps (d) and (e) until the concave portion is formed in the material. Method. 2. A method for forming, on a material, a convex portion having at least a part formed of a curved surface, wherein: (a) a contour line obtained by dividing numerical data of a concave portion surrounding the convex portion to be formed by a predetermined difference in height; Dividing into numerical data for each of a plurality of concave portions having different heights in the upper and lower directions, and (b) based on the numerical data for each of the concave portions, an elongate first having a cutting blade formed at a tip and a side surface. Using the rotating tool of
Cutting a contour groove having a depth equal to the thickness of the highest concave portion inside the contour line along a contour line defining the highest concave portion; and (c) based on numerical data for each of the concave portions. Using a second rotary tool that is thicker than the first rotary tool, the area outside the contour groove cut in the previous process is cut, and the material having the highest concave portion is formed into a shape having a flat bottom. (D) on the basis of the numerical data for each of the concave portions, using the first rotating tool, on the bottom surface of the concave portion formed in the previous step,
(E) cutting a contour groove having a depth equal to the thickness of the concave portion inside the contour line along a contour line defining a concave portion having a height next to the concave portion formed in the previous step; Based on the numerical data for each of the concave portions, using the second rotary tool, cut the area outside the contour groove cut in the previous process, and continuously flatten under the already formed concave portion. Forming a new concave portion having a proper bottom surface; and (f) repeating (d) and (e) until the concave portion is formed in the material. . 3. The cutting method according to claim 1, wherein prior to cutting of the contour groove by the first rotary tool, along a cutting line at which the contour groove is to be formed. A cutting groove formed by the first rotary tool. 4. The cutting method according to claim 3, wherein the guide groove is formed by moving the first rotary tool a plurality of times along a cutting line. Processing method. 5. The cutting method according to claim 1, wherein the difference between the predetermined heights is 3 μm to 50 μm. 6. The cutting method according to claim 1, wherein the first rotary tool has a cutting blade at a tip and a side surface and has a diameter D of 1 mm or less. A cutting method comprising a cutting tool having an elongated cylindrical cutting portion having a ratio L / D of an effective length L and a diameter D of 10 or more.