JPH0811006A - Processing method using diamond cutting tool - Google Patents

Abstract

(57) [Summary] [Purpose] A new polished diamond cutting tool does not require "break-in" before cutting a work piece, and makes the work piece a high-quality cut surface from the start of use. A processing method using a diamond cutting tool that can be processed is provided. [Structure] A front cutting edge ridge a ₁ which is a line of intersection between a rake face 1 and a front flank 2 of a diamond cutting tool forming a cutting edge by providing a rake face 1, a front flank 2 and a lateral flank 6
In addition, a width of 0.
The object to be cut is mirror-cut with a diamond cutting tool provided with a chamfer of 2 to 0.8 μm in advance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a processing method using a diamond cutting tool, particularly, a nonferrous metal material such as aluminum (hereinafter referred to as Al) or copper (hereinafter referred to as Cu), or a nonmetallic material such as plastic. The present invention relates to a processing method using a diamond cutting tool for highly accurately cutting an object to be cut such as a disc.

[0002]

2. Description of the Related Art Generally, a diamond cutting bit is used for high-precision cutting of a non-ferrous metal material such as Al or Cu, or a non-metal material such as plastic. It is well known that a so-called mirror finished surface can be relatively easily obtained. The reason is that the diamond cutting tool has a high hardness, and therefore the cutting edge of the diamond cutting tool can be ground to be extremely sharp, and as a result, this sharp cutting edge is transferred to the object to be cut. This is because a cut surface with good surface roughness is formed.

[0003] However, in reality, the cutting surface cut by the new polished sharp cutting edge of the diamond cutting tool has a scratch mark due to the falling-off of the inclusions inside the workpiece, or the material itself to be cut. Therefore, the cut surface is often not good. Therefore, at the site where cutting is performed, a new diamond cutting tool is used to cut the dummy cutting material before using it for cutting to prevent the occurrence of defects on the cutting surface. "Break-in cutting" is performed to wear the cutting edge ridge to some extent.

This is based on the following grounds. In other words, a good cutting surface close to a mirror surface can be obtained by machining with a diamond cutting tool. First, cutting is performed on the side flank, and the trace of the occurrence of the soreness is very thin chip on the front flank. This is because there is a possible processing mechanism of cutting while discharging. For this reason,
Japanese Patent Publication No. 58-37082, which describes a prior art for extending the life of a diamond cutting tool, describes a crystal orientation of a flank before forming a part of a cutting edge of a diamond cutting tool by using a (110) plane. And the (100) plane, and as a condition for keeping the sharpness of the cutting edge forever, it is essential that the front flank be appropriately worn to make the burnishing effect work moderately. It is explained. However, there is no mention of an appropriate value of this amount of wear, which is moderate wear, and there is no description of how to machine the cutting edge and how to achieve accuracy.

[0005]

As described above, in the prior art, "cut-in" is still required before cutting a work piece with a new polished diamond cutting tool, and this "break-in" is required. "Cutting" is simply "run-in cutting", and there is no consideration regarding the wear angle of the cutting edge of the diamond cutting tool and the appropriate value of the wear amount.
In addition to the need for man-hours for dummy cutting, there is a problem that it is difficult to obtain a good cut surface. The present invention solves the above-mentioned problems of the prior art and eliminates the need for “break-in” before cutting a work piece with a new ground diamond cutting tool, so that the work piece can be cut from the start of use. It is an object of the present invention to provide a processing method using a diamond cutting tool capable of processing a high quality cutting surface.

[0006]

A processing method using a diamond cutting tool according to the present invention for achieving the above object is a diamond forming a cutting edge by providing a rake face, a front flank and a side flank. Depending on the wear angle peculiar to the diamond cutting tool, the width of the front cutting edge, which is the line of intersection between the rake face and the front flank of the cutting tool, is 0.2 to
The object to be cut is mirror-finished using the diamond cutting tool provided with a chamfer of 0.8 μm in advance.

[0007]

In the working method using the diamond cutting tool of the present invention, the front cutting edge ridge, which is the line of intersection between the rake face and the front flank, has a width of 0.
Since the object to be cut is mirror-finished by using a diamond cutting tool with a chamfer of 2 to 0.8 μm, “break-in” of the diamond cutting tool is not necessary in the cutting process, and even if wear progresses The volume of the wear portion of the cutting edge becomes stable, and as a result, the roughness of the cutting surface becomes almost constant from the start of use of the diamond cutting tool, and a high quality cutting surface can be obtained.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Before starting the description of the embodiments, the basic matters according to the present invention will be described with reference to the drawings. 3 to 6 are explanatory views of basic matters according to the present invention, and FIG. 3 is a perspective view of essential parts showing a worn state of a cutting edge of a diamond cutting tool, and FIG.
Is a side view of the cutting edge according to FIG. 3, FIG. 5 is an enlarged perspective view schematically showing the front cutting edge ridge wear part in FIG. 4, and FIG. 6 is a volume and cutting surface roughness of the front cutting edge ridge wear part. It is a characteristic diagram which shows the relationship of. Generally, when a soft non-ferrous metal such as Al or Cu is mirror-cut with a diamond cutting tool, as the cutting amount increases, as shown in FIG. 3, the rake face 1 and the front flank face 2 are in front of each other. The front cutting edge wear surface 4 is on the cutting edge ridge a,
Further, a horizontal cutting edge wear surface 5 is formed on a horizontal cutting edge ridge b which is an intersection line between the rake face 1 and the lateral flank 6. Of the two wear surfaces, the length c of the front cutting edge wear surface 4 is substantially equal to the diamond cutting tool feed amount per one revolution of the object to be cut.

Among the two wear surfaces, the one having a large effect on the roughness of the cutting surface is the front cutting edge wear surface 4,
As shown in FIG. 4, the front cutting edge wear surface 4 has a wear angle θ (front cutting edge wear surface 4
Is formed in the direction of the vertical line formed on the rake face 1), and this direction is known to substantially coincide with the (110) crystal face of diamond, which is the material of the diamond cutting tool. Δ shown in the front cutting edge ridge wear portion 3 (broken line portion in FIG. 4) is a retreat amount due to wear of the front cutting edge ridge measured from the front cutting edge ridge a to the horizontal cutting edge ridge b.

The present inventors have paid attention to the change in the cutting surface roughness when a new diamond cutting tool is used and the change in the cutting surface roughness due to the worn diamond cutting tool.
The diamond cutting tool wear volume of the front cutting edge ridge a of the diamond cutting tool that wears as described above, that is, the volume of the front cutting edge ridge wear portion 3, and the cutting of the workpiece cut by the diamond cutting tool during wear. When the relationship with the surface roughness was tested using a plurality of diamond cutting tools, the results shown in FIG. 6 were obtained.

From the characteristic diagram showing the relationship between the volume of the front cutting edge ridge wear portion 3 and the cutting surface roughness shown in FIG. 6, when the diamond cutting tool wear volume is 0, that is, the diamond cutting tool has a new front cutting edge. When the ridge a is sharp, the cut surface roughness is as poor as 0.10 μmR _max . When the wear progresses, the cut surface roughness sharply increases, and when the diamond cutting tool wear volume becomes 8 × 10 to ¹⁰ mm ³ or more, Further, it was found that the roughness of the cut surface was further improved and became almost constant and stable.

Based on the results found from the data of FIG. 6, a new diamond cutting is prepared by previously providing the front cutting edge ridge a with a chamfer corresponding to the wear volume of the diamond cutting tool of 8 × 10 to ¹⁰ mm ^3. The "break-in" that has been performed on the cutting tool is no longer necessary, and even if the front cutting edge ridge of the diamond cutting tool is worn out, the cutting surface roughness of the object to be cut by the diamond cutting tool is almost accurate. A constant and high quality cut surface can be obtained from the start of use of a new diamond cutting tool.

Here, how to determine the dimensions of the chamfer will be described with reference to FIG. In FIG. 5, the same reference numerals and symbols as those in FIGS. 3 and 4 denote the same parts. And d is the chamfer width. Assuming that the shape of the front cutting edge ridge wear part 3 is a prism whose cross section is a right triangle (the length of the hypotenuse is d), the diamond cutting tool wear volume V is given by the following equation.

## EQU1 ## V = (c / 2) × Δ × dcos θ Substituting Δ = dsin θ into this Equation 1 gives

[Number 2] V = (c / 4) d 2 sin2θ Solving this equation 2 for d,

(Equation 3) Becomes

By the way, the length c of the front cutting edge wear surface 4 is almost equal to the feed amount of the diamond cutting tool per one revolution of the object to be cut, and is usually about 50 μm. And the wear angle θ
Is unique to each diamond cutting tool, usually 3
° to 45 °. In the above Equation 3, V is the diamond cutting tool wear volume of 8 × 10 to ¹⁰ mm ³ (= 0.
8 μm ³ ) and wear angle θ = 3 °, d =
0.78 μm, and if the wear angle θ = 45 °, d =
0.25 μm. Therefore, a chamfer having a chamfering width d of 0.2 to 0.8 μm is provided in advance on the front cutting edge ridge a in accordance with the wear angle θ specific to the diamond cutting tool (the crystal orientation of the diamond cutting tool is different). It turns out that it is good.

The present invention has been made based on the above-mentioned basic matters, and the embodiments will be described below. FIG. 1 is a perspective view of a main part showing a cutting edge of a diamond cutting tool according to an embodiment of the present invention, and the same reference numerals as those in FIG. 3 denote the same parts. In FIG. 1, a ₀ is a front cutting in which a chamfering width d of 0.2 to 0.8 μm is provided as the chamfer 7 over the entire length of the front cutting edge ridge depending on the wear angle peculiar to the diamond cutting tool described in the basic matter. It is a ridge.
This chamfer 7 has a crystal orientation of (1) of diamond.
10) It is formed to be a plane.

Since the chamfer 7 is formed as described above, the diamond cutting tool is not subjected to "break-in cutting" beforehand, and even if the wear of the diamond cutting tool progresses, the cutting surface roughness of the workpiece by the diamond cutting tool is increased. Is almost constant, and a high-quality machined surface can be obtained from the start of use. In other words, there is an effect that highly accurate mirror surface cutting can be easily performed. Further, since the chamfer 7 is formed so that the crystal orientation thereof is the (110) plane, the wear surface coincides with the natural wear surface from the beginning, and the diamond cutting tool wear volume is minimized. In addition, since the chamfer 7 is provided over the entire length of the front cutting edge, there is an advantage that the diamond cutting tool can be easily manufactured. In this embodiment, the crystal orientation of the chamfer 7 is (11).
Although the plane is set to the 0) plane, it is not always necessary to provide the plane to the (110) plane. If provided on the (110) plane, the tool wear volume is the smallest.

FIG. 2 is a perspective view showing a main part of a cutting edge of a diamond cutting tool according to another embodiment of the present invention.
The same reference numerals denote the same parts. In FIG. 2, a ₁ represents a chamfering width d of 0.2 to 0.8 μm according to the wear angle peculiar to the diamond cutting tool described in the basic matter, and the diamond per revolution of the object to be cut at the front cutting edge. It is a front cutting edge provided as a chamfer 7A having a length 1 or more of a cutting bite feed amount (for example, 50 μm). This chamfer 7A has a crystal orientation of (110) of diamond.
It is formed so that it becomes a surface.

The diamond cutting tool thus constructed is also provided with a chamfer 7A on the front cutting edge ridge a _{1 so} that the cutting surface roughness is substantially constant. Even if wear of the diamond cutting tool progresses without cutting, the cut surface roughness of the object to be cut by the diamond cutting tool is substantially constant, and a high quality cut surface can be obtained from the start of use.

[0019]

EFFECTS OF THE INVENTION According to the present invention, a new diamond cutting tool does not require "break-in" and a diamond cutting tool capable of processing a high quality cutting surface from the start of use It is possible to provide a modified processing method.

[Brief description of drawings]

FIG. 1 is a perspective view of essential parts showing a cutting edge of a diamond cutting tool according to an embodiment of the present invention.

FIG. 2 is a perspective view of a main part showing a cutting edge of a diamond cutting tool according to another embodiment of the present invention.

FIG. 3 is a perspective view of a main part showing a worn state of a cutting edge of a diamond cutting tool.

FIG. 4 is a side view of the cutting edge according to FIG.

FIG. 5 is an enlarged perspective view schematically showing a front cutting edge ridge wear portion in FIG. 4;

FIG. 6 is a characteristic diagram showing the relationship between the volume of the front cutting edge ridge wear portion and the cutting surface roughness.

[Explanation of symbols]

1 ... rake face, 2 front flank face, 6 ... lateral flank face, 7, 7A
... chamfering, a _0, a ₁ ... before cutting edge, d ... chamfer width, l ...
Chamfer length.

Claims (1)

[Claims] 1. A diamond cutting tool for forming a cutting edge by providing a rake face, a front flank, and a side flank, the diamond cutting being provided on a front cutting edge ridge which is a line of intersection between the rake face and the front flank. A machining method using a diamond cutting tool, characterized in that the diamond cutting tool is provided with a chamfer having a width of 0.2 to 0.8 μm according to the wear angle peculiar to the cutting tool, and the object is mirror-cut.