JPS6236562Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a throw-away tip for finish cutting, and is particularly designed to have good chip disposal properties.

Conventionally, there have been relatively few problems with chip disposal during finish cutting, and the applicant has
The one shown in Publication No. 165704 has been proposed.
This has a notched step on the rake face side of the nose.
A protrusion protruding from the central boss surface is formed within this notch step, and the notch step is parallel to the central boss surface, and the cutting edge is at a lower level than the protrusion. Therefore, chip disposal is carried out by the protruding parts, but they are not necessarily good in terms of cutting resistance and chip disposal properties.In recent years, chip breakers suitable for finish cutting have been developed in pursuit of chip disposal properties. has become required.

The present invention was developed in view of the above-mentioned points, and a notch step is provided on the polygonal surface side of the nose configured at the corner portion so that a positive rake angle θ is formed, and this notch At the center of the step, there is a throw-away tip with a protruding portion that is lower than the central boss surface and protrudes toward the cutting edge, and its height is approximately the same as the cutting edge of the nose. It provides:

An embodiment of the throw-away chip of the present invention will be described below with reference to the drawings.

In FIGS. 1 to 3, reference numeral 1 denotes a triangular plate-shaped throw-away tip having, for example, a central mounting hole 2, the corner portion of which constitutes an upper cutting nose 3.

The polygonal rake face side of the nose 3 has a positive rake angle θ, for example, 3° to 20°, in the direction of the bisector of the nose 3, as shown in Fig. 3. A cutout step portion 4 is provided. Therefore, the cutting edge 5 on the nose 3 of the throw-away chip 1 is located at a lower position relative to the central boss surface 6 in the thickness direction of the chip.

Further, in the center of this notch step portion 4, a protruding portion 7 necessary for chip disposal is provided so as to protrude toward the cutting edge 5 in the direction of the bisector of the nose 3. In this case, the height of the protruding portion 7 is lower than the central boss surface 6, and is approximately at the same height as the cutting edge 5 of the nose 3 described above. This is a consideration to expand the processing efficiency of chips in finishing cutting, especially the range of small depth of cut and small feed.

Further, in order to apply the throw-away tip 1 to high-speed cutting, it is preferable to manufacture it from a TiC-based, TiN-based cermet, ceramics, etc., rather than from a WC-based cemented carbide.

Cutting tests for product A of the present invention and conventional product B will be described below.

Regarding the tool specifications of the invented product A and the conventional product B, both had the basic shape of TNMG332. The product A of the present invention has a third notch step 4.
As shown in the figure, the cutting edge 5 is 0.05 mm lower than the central boss surface 6, and the radius of curvature is
A circular arc surface was formed with 3.9mm. In this case, nose 3
The cutting length from the cutting edge 5 to the central boss surface 6 on the bisector of 2.33 mm. In addition, the protruding portion 7
is 1.0mm apart from the nose 3 in Figure 3,
The tip was rounded with a radius of curvature of 1.0 mm. The height at this time was made to match the cutting edge 5 of the nose 3. On the other hand, conventional product B is
As disclosed in Japanese Patent No. 165704, the notch step portion referred to in the present invention is parallel to the central boss surface, and the cutting edge thereof is located at a lower level than the protruding portion. Furthermore, the comparative product C has the protruding portion 7 located at the intermediate height between the cutting edge 5 and the central boss surface 6, and the other shape and dimensions are the same as the product A of the present invention.

Inventive product A, conventional product B, and comparative product C
Then, the work material made of S48C was cut at a speed of V = 150 m/
When cutting at min, the effective range of chip disposal was the area clearly shown in Fig. 4.

That is, the product A of the present invention has improved chip disposal performance over the conventional product B in the range of small depth of cut and small feed. Comparative product C is improved over conventional product B in small feed and small depth of cut, but
Chip disposal becomes worse at large depths of cut due to a decrease in cutting edge strength. This is because a positive rake angle θ is provided in the area from the cutting edge 5 to the protruding portion 7, which improves cutting quality, and the height of the cutting edge 5 relative to the protruding portion 7 improves the strength of the cutting edge. This is because it is enhanced.

FIG. 5 shows the height of the burr using the aforementioned rake angle θ as a parameter. As a result, it can be seen that the height of the burr is reduced in the positive rake angle portion adopted in Product A of the present invention. On the other hand, as seen in conventional product B, θ=
In the case of 0, the height of the burr was about 1.8 mm.
The work material at this time was S48C, and the cutting conditions were: cutting speed V = 150 m/min, depth of cut d =
The setting was 2.0 mm and the feed f = 0.2 mm/rev.

In the throw-away tip 1 of the present invention thus constructed, the addition of the rake angle θ at the cutting edge 5 of the notch step 4 reduces cutting resistance and improves sharpness.

In addition, the throw-away tip 1 of the present invention allows chips to be easily disposed of because chips are drawn toward the protrusion 7 by adding the rake angle θ and positioning the protrusion 7 at an appropriate height. This improves chip disposal properties.

[Brief explanation of the drawing]

FIG. 1 is a front view showing an embodiment of the throw-away tip of the present invention, FIG. 2 is a side view thereof, and FIG.
The figure is an enlarged partial cross-sectional view taken along the - line in Fig. 1, and Fig. 4 is an explanation for comparing the chip processing characteristics of the present product A, the conventional product B, and the comparative product C. 5 are explanatory diagrams showing the height of the burr at the notch step portion with respect to the inclination angle θ. 3...Nose, 4...Notch step, 5...Cutting edge ridge, 6...Central boss surface, 7...Protrusion portion.

Claims (1)

[Claims for Utility Model Registration] The nose 3, which has a polygonal plate shape and is formed at the corner portion of the polygonal surface, is provided with a cutout step portion 4 having a protruding portion 7, so that the central portion has a cutout step portion 4. In the throw-away chip in which a central boss surface 6 is formed, the notch step portion 4 has a cutting edge 5 formed by intersecting with the circumferential surface in the thickness direction of the chip. The protruding portion 7 is located at a lower position than the central boss surface 6 in the direction of the bisector of the nose 3, and forms a positive rake angle θ in the direction of the bisector of the nose 3. It is characterized by protruding toward the edge 5 and having a height in the thickness direction that is lower than the central boss surface 6 in the direction of the bisector of the nose 3 and is approximately the same as the cutting edge 5. Throwaway tip.