JPH045202Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a throw-away tip particularly equipped with a chip breaker groove, and is particularly suitable for medium-heavy cutting.

(Prior Art) Conventionally, this type of throw-away chip has been disclosed, for example, in Japanese Unexamined Patent Application Publication No. 48-52078 and Japanese Utility Model Application No. 55-52
Those found in Publication No. 129707 and the like are disclosed. The throw-away tip disclosed in the former publication has a cutting edge having an uneven waveform shape and the depth of the tip breaker groove is varied. In particular, FIG. 10 shows a tool having a convex boss surface with a straight cutting edge near the nose and a concave curve near the center.

Furthermore, the throw-away tip disclosed in the latter publication is equipped with a breaker groove all around the circumference, and also forms a land portion whose height changes along the periphery of the central convex boss surface. . In this case, the land portion changes to be higher near the nose and lower near the center relative to the height of the cutting edge.

(Problem that the invention attempts to solve) However, what is seen in the former publication is
Chip control is effective in the range of heavy cutting where the depth of cut and feed are large due to changes in the waveform cutting edge and the breaker depth, but in the range of medium cutting as there is no land area as seen in the latter publication. There was a problem that chip disposal was not always good.

In addition, the latter publication deals with variations in the depth of cut and feed due to changes in the height of the land area, but since the cutting edge itself is a straight edge, chip control in heavy and medium cutting areas is difficult. There was a problem that the quality was not good.

For this reason, the present invention is based on the assumption that the boss surface has a concave shape, and the cutting resistance is small.
The present invention also provides a throw-away tip that has a cutting edge shape and a chip breaker groove shape that can be applied in a feed f range of 0.3 to 1.2 mm/rev.

(Means for solving the problem) The present invention has a polygonal plate shape, and a chip breaker groove with a narrow land and a cutting edge ridge that changes in concavity and convexity are formed on the outer peripheral edge. This is an improvement based on the premise of a throw-away tip with a concave boss surface. That is, the cutting edge has a straight cutting edge in the vicinity of the nose and a concave cutting edge in the center of the side when viewed from the side.

Further, the chip breaker groove has a downward inclination angle θ in the transverse direction from the land to the boss surface.
A full circumference protrusion in the circumferential direction and a nose protrusion in the direction of the bisector of the nose apex angle are formed following the inclined surface having the following. These full-circumferential protrusions and nose protrusions are located at a lower level than the straight cutting edge ridge, and the upper surface of the circumferential protrusions exhibits wave-shaped unevenness forming three peaks between the nose protrusions. It has been changed as follows.

(Function) In the region where the depth of cut is small, the throw-away chip of the present invention curls chips upward by the nose protrusion formed in the chip breaker groove on the bisector of the nose apex angle, thereby making chip disposal effective. In addition, in areas where the depth of cut is large, the incline provided due to the presence of the cutting edge exhibiting a concave ridge guides the chips toward the front to prevent chip clogging, and the entire circumferential protrusion disposes of the chips.

Furthermore, the nose protrusion, all-round protrusion, and medium-concave boss surface are located at a lower level than the cutting edge edge, are provided with an incline, and the upper surface of the all-round protrusion has three wave-like irregularities between the nose protrusions. Because of this change, it acts to reduce the cutting resistance during heavy cutting.

(Example) Hereinafter, an example of the throw-away chip of the present invention will be described with reference to the drawings.

In FIGS. 1 to 4, reference numeral 1 denotes a throw-away tip in the form of, for example, a diamond-shaped plate, and a chip breaker groove 3 with a narrow land 2 is formed on the polygonal rake face side. ing. A cutting edge 4 is formed by the land 2 and the side surface, and as the land 2 becomes uneven, the cutting edge 4 exhibits a straight cutting edge 4a near the nose, and At the center, a concave cutting edge 4b is formed. This is so that an inclination is provided along with the formation of the concave edge 4b.

Further, in the chip breaker groove 3, in the transverse direction from the land 2 to the medium concave boss surface 9, a peripheral protrusion 6 and a concave surface 10 are formed following a sloped surface 5 having a downward slope angle θ, Further, in the direction of the bisector of the apex angle, a nose protrusion 7 is formed which is lower than the straight cutting edge 4a and which is larger than the circumferential protrusion 6 at the intersection with the circumferential protrusion 6. . These circumferential protrusions 6, nose protrusions 7, and concave boss surfaces 9 are formed to be lower than the straight cutting edge 4a, thereby reducing chip contact area and chip resistance. I try to do that.

Further, the upper surface of the circumferential protrusion 6 changes in wave-like unevenness between the nose protrusions 7. In this case, the waveform unevenness changes such that it rises up from the connecting portion of the nose protrusion 7 and becomes a convexity, and then concave from this convexity to become a convexity at the center of the side, forming so-called three peaks. The reason for providing such wave-shaped irregularities is to reduce the cutting resistance by reducing the chip contact area, and
The aim is to reduce the amount of heat generated. The upper surface of the circumferential protrusion 6 is at a lower level when compared in the transverse direction with respect to the straight cutting edge 4a and the concave cutting edge 4b. This is a consideration that makes it especially suitable for medium-heavy cutting, and is different from the change in the land area seen in the latter publication mentioned above.

Note that 9 on the boss surface indicates the straight cutting edge 4a and the concave cutting edge 4b of the cutting edge 4, as described above.
It is a medium-concave shape that is lower than the other side. The reason why the boss surface 9 is formed into a concave shape is to reduce the chip contact area since the chips do not come into contact with the boss surface 9, thereby reducing cutting resistance and heat generation.

The throw-away chip 1 of the present invention constructed in this way is shown in FIGS. 7a and 7b and FIGS.
As shown in c, good chip disposal is achieved even when the depth of cut is 2 mm or less, and it can also be used with a depth of cut of about 10 mm. Further, the cutting feed is normally applied in the range of 0.3 to 1.2 mm/rev. In addition,
Inclination angle θ formed by chip breaker groove 3
For example, the angle is large due to the medium concave boss surface 9.
An angle of 10° to 30° can be adopted, thereby reducing the cutting force.

FIGS. 7a and 7b show how chips are discharged when the depth of cut is small. That is,
Chips generated by cutting are curled by the nose protrusion 7 and eventually broken. Also, the 8th
Figures a to c show how chips are discharged when the depth of cut is large. That is, due to the inclineation effect, the chips generated during cutting are guided in a slightly side-curled manner as shown by the arrow, and clogging of chips is prevented. Next, the guided chips are curled by the nose protrusion 7 and the circumferential protrusion 6, and are finally broken.

Further, although this embodiment was applied to a diamond-shaped throwaway chip with a center mounting hole 8, it is of course applicable to a throwaway chip without a center mounting hole 8, a square plate shape, a triangular plate shape, etc. be. In addition, to improve cutting performance,
It is also effective to form a hard coating layer such as TiC or TiN.

FIG. 5 compares the effective range of chip disposal between the product A of the present invention and the conventional product B. In this case, the work material is S48C, and the cutting speed V is V=
The cutting speed was set at 100 m/min, and the conventional product B had only a straight cutting edge without the concave edge 4b, and also did not have the nose protrusion 7 and the circumferential protrusion 6. The basic shape of the tool specifications is CNMM644.

As a result, the product A of the present invention has a larger range of cutting and feed than the conventional product B due to the presence of the concave ridge 4b, and due to the presence of the nose protrusion 7,
The small range of depth of cut and feed has been expanded. Also,
Due to the presence of the circumferential protrusion 6, the range of large cuts is respectively enlarged with a small feed.

Furthermore, FIG. 6 shows the present invention product A and comparative product B.
This is a comparison of the magnitude of cutting resistance (combined force) at The results show that product A of the present invention has low cutting resistance. In this case, the workpiece material is
With SCM415 (H _B = 145~165), cutting speed V =
The cutting speed was set at 100 m/min and the depth of cut was 6 mm.

(Effects of the invention) The throw-away chip 1 of the present invention has a full circumferential protrusion 6 and a nose protrusion 7 that change with wave-like unevenness in the chip breaker groove 3, and a land 2.
And since the incline is given so as to give unevenness changes to the cutting edge 4,
It has the following effects.

First, the chip disposal range is expanded. This is made clear in Fig. 5. In areas where the depth of cut is small, the chips are curled up due to the presence of the nose protrusion 7 and the straight cutting edge 4a, and in areas where the depth of cut is large, the chips are curled up in the ink. This is because the lineation guides the chips to the front and prevents the chips from clogging, and then the chips are disposed of by the entire circumferential protrusion 6 having wave-like irregularities.

Further, as described above, the formation of the concave cutting edge 4b provides inclineation, and as a result, an effect is also imparted to end face pushing and pulling cutting.

Second, cutting resistance is reduced. This is made clear in Fig. 6, but the entire circumference protrusion 6, nose protrusion 7, and boss surface 9 are located lower than the cutting edge 4, are provided with an incline, and the circumferential protrusion This is because the unevenness is given to the top surface of 6. Note that cutting resistance is also reduced by increasing the inclination angle θ.

[Brief explanation of the drawing]

FIG. 1 is a front view showing one embodiment of the throw-away tip of the present invention, FIG. 2 is a bottom view thereof, and FIG.
Figure a is a partially enlarged sectional view taken along line a-a in Figure 1, and Figure 3 b is a partially enlarged sectional view taken along line a-a in Figure 1.
- Partially enlarged sectional view taken along line b, No. 4
The figure is a partially enlarged sectional view taken along the - line in Figure 1, Figure 5 is an explanatory diagram showing the effective range of chip disposal in product A of the present invention and comparative product B, and Figure 6 is , FIG. 7a is an explanatory diagram showing the state of chip discharge when the depth of cut is small, and FIG. 7b is an explanatory diagram showing the comparison of cutting forces. FIG. Partially enlarged sectional view, No. 8
Figure a is an explanatory diagram showing the state of chip discharge when the depth of cut is large, and Figure 8 b is an illustration of b in Figure 8 a.
FIG. 8c is a partially enlarged sectional view taken along line C--C in FIG. 8a. 1... Throwaway chip, 2... Land,
3... Chip breaker groove, 4... Cutting edge 4a...
Straight cutting edge ridge, 4b... Concave cutting edge ridge, 5... Inclined surface, 6... Full circumference protrusion, 7... Nose protrusion.

Claims (1)

[Claims for Utility Model Registration] A chip breaker groove 3 having a polygonal plate shape and having a narrow land 2 along a cutting edge 4 formed on the outer periphery is formed on the polygonal rake face. In the throw-away tip, which is provided with a concave boss surface 9 in the center thereof, the cutting edge 4 has a straight cutting edge 4a near the nose when viewed from the circumferential side direction. The chip breaker groove 3 has a downward inclination angle θ in the transverse direction from the land 2 to the boss surface 9.
Following the inclined surface 5 having a circumferential all-round protrusion 6
and nose protrusion 7 in the direction of the bisector of the nose apex angle
are formed such that they are each located at a lower level than the straight cutting edge 4a, and the upper surface of the entire circumferential protrusion 6 exhibits a wave-like unevenness between the nose protrusions 7, and this wave-like unevenness rises from the connecting part of the nose protrusion 7. This convexity becomes concave, and then changes sequentially to a convexity at the center of the side to form three ridges, and the straight cutting edge 4
A throw-away tip characterized in that both a and a concave cutting edge 4b are at a lower position when compared in the transverse direction.