JPH1110412A - Cutting insert - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cutting insert that even in the cutting work of hot rolled soft iron or cold rolled plates and the like, chips are securely hit the projection of a braker to provide a good chip dischargeability for curling and stably discharging chips. SOLUTION: In the end part of a nose part 4 in which a braker projection 8 is formed in the central part of a braker groove 6, the braker groove 6 is made to be shallow and wide in breadth, and to have a smaller rake angle from the cutting edge, and further the cutting edge 3 is made to be descended downward at a prescribed angle to both sides from the cutting edge end 5 of the nose part 4. In other words, the difference E in level between the cutting edge end 5 of the nose part 4 and the braker groove 6 is made to be 0.01 to 0.1 mm, the distance F from the cutting edge end 5 to the rising start point of the braker projection 8 is made 0.3 to 0.7 mm, the rake angle α ranging from the cutting edge end 5 to the braker groove 6 is made 2 deg. to 13 deg., and the descending angle βof the cutting edge 3 from the cutting edge end 5 is made to be 4 deg. to 8 deg..

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used for a material such as a hot-rolled soft iron or a cold-rolled plate, which is easy to be continuously cut without cutting when it is cut. And a cutting insert for the same.

[0002]

2. Description of the Related Art Conventionally, in order to cut such a material having high ductility by cutting, a breaker groove and a breaker projection connected to the breaker groove are provided near the tip of a nose of a polygonal plate. Formed ones have been used.

[0003] In such a cutting insert, the shape of the nose is such that the distance from the tip of the nose to the rise of the breaker projection, that is, the width of the breaker groove is very small, and the width is small, but the depth is large. The rake angle of the rake face in the breaker groove continuous with the rake angle was relatively large, whereas the rising angle of the breaker projection was small and gentle. The cutting edge of the nose of such a cutting insert is usually formed almost horizontally.

Typically, the distance from the tip of the nose to the rise of the breaker projection is about 0.4 mm, the depth of the breaker groove is 0.1 mm, and the rake angle of the rake face in the breaker groove is about 15 °. Has been used.

[0005] However, the above-mentioned conventional cutting insert cannot completely solve the problem that chips are discharged without being bent by the breaker projections. Poor processing was a problem.

[0006] This is because the R surface remains at the corner of the step,
When the processing direction is changed from the horizontal direction to the vertical direction or the opposite direction, the cutting amount temporarily increases. For this reason, the result is that the cutting processing is performed beyond the chip processing capacity.

[0007] When the chips are extended in this manner, serious problems are caused, such as entanglement with the rotating center of the machine tool, interrupting the work, or tangling the cutting edge, causing the cutting edge to be defective.

[0008]

DISCLOSURE OF THE INVENTION In view of the above-mentioned problems of the prior art, the cutting blade is formed in a spiral shape even for a material such as a hot-rolled soft iron or a cold-rolled plate, which is likely to be discharged in a band shape without breaking when cutting is performed. An object of the present invention is to provide a cutting insert that can be reliably curled and discharged stably.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems in the prior art, a cutting insert according to the present invention has a structure in which a breaker groove is formed shallow and wide at a tip portion of a nose portion having a breaker projection formed at a central portion of the breaker groove. Thus, the rake angle from the cutting edge was made small, and the cutting edge was made to descend from the tip of the cutting edge of the nose to both sides at a constant angle. That is, the step E between the tip of the cutting edge of the nose and the breaker groove is 0.01 to 0.1 mm, and the distance F from the tip of the cutting edge to the starting point of the breaker projection is 0.3.
0.7 mm, the rake angle α from the tip of the cutting edge to the breaker groove is 2 ° to 13 °, and the downward angle β of the cutting edge from the tip of the cutting edge is 4 to 8 °.

[0010]

According to the cutting insert of the present invention, as described above, the breaker groove is shallow and narrow at the tip of the nose where the breaker projection is formed at the center of the breaker groove, and the rake angle from the cutting edge is small. In addition, the cutting edge is designed to descend at both sides from the tip of the cutting edge of the nose at a constant angle, and chips from the cutting edge surely hit the groove bottom of the shallow breaker groove and bounce so as to slide. After that, it hits the breaker projection and curls spirally with a small radius of curvature without deceleration because the breaker groove is narrow. At this time, as described above, since the cutting edge is lowered at a fixed angle to both sides from the tip of the cutting edge of the nose portion, the chip smoothly flows toward the breaker projection in both the pulling process and the pushing process. Therefore, chips are easily cut and the cutting resistance does not increase. Further, since the rake angle of the breaker groove is small, the edge strength is high. Therefore,
In the cutting insert of the present invention, the chip reliably hits the breaker projection in both the pulling process and the pressing process, and is curled and discharged stably. Even when the amount changes, chips are satisfactorily processed.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIGS. 1 to 4 show a cutting insert 10 according to the present embodiment, and the overall shape of the cutting insert 10 is a rhombus shape in which the nose portion 4 has a relatively large cutting edge angle, and is formed between the rake face 1 and the flank 2. The cutting edge 3 is formed on the ridge.

The nose portion 4 has a breaker groove 6 continuous with the cutting edge 5 and a breaker projection 8 continuous with a seating surface 7 at the center of the breaker groove 6.

As shown in the sectional view of FIG. 3, the cutting insert 10 has a step E between the cutting edge 5 of the nose 4 and the breaker groove 6 at the tip of the nose 4 of 0.01 to 0. .1 mm, and the distance F from the cutting edge 5 to the starting point 11 of the breaker projection 8 is 0.3
And the rake angle α from the cutting edge 5 to the breaker groove 6 is 2 ° to 13 °. That is, the breaker groove 6 is shallow and wide, and the rake angle α ° from the cutting edge 3 is small, and chips from the cutting edge 3 surely hit the groove bottom of the shallow breaker groove 6 and bounce so as to slide. Since the breaker groove 6 is narrow and hits the breaker projection 8, the curl is spirally curled with a small radius of curvature without deceleration.

Further, as shown in a partially enlarged view of FIG.
The cutting edge 3 is designed to descend at both sides from the tip of the nose 4 at a constant angle, that is, a downward angle β ° = 4 to 8 °. , The chips flow smoothly toward the breaker projections 8 in both pulling and pushing, so that the chips are easily cut and the cutting resistance does not increase. . Further, since the rake angle α ° of the breaker groove 6 is small, the edge strength is large. Therefore,
In the cutting insert 10, in both the pulling process and the pressing process, the chip reliably hits the breaker protrusion 8, curls and is stably discharged, and further, when the corner portion of the step portion is processed, a sharp cut is made. Even when the amount changes, chips are satisfactorily processed.

When the step E is less than 0.01 mm, the cutting resistance is increased, and the cutting edge 5 may be easily oxidized and abraded. There is a risk that it will.

If the distance F is less than 0.3 mm, the cutting resistance increases, and the cutting blade tip 5 may be easily oxidized and worn. On the other hand, if it exceeds 0.7 mm, the chips may be elongated.

If the rake angle α ° is less than 2 °, the cutting resistance increases, and the cutting edge 5 may be easily oxidized and worn. On the other hand, if it exceeds 13 °, there is a possibility that the chips may be elongated.

If the descending angle β ° is less than 4 °, the direction in which the chips are discharged is unstable, and the chips tend to be easily entangled. On the other hand, if the angle is more than 8 °, the chips may be elongated.

In addition to such a structure, the cutting insert 10 is provided so that chip processing can be performed well in both pulling and pushing. That is,
A plurality of grooves 9a having a planar bottom surface extending in a direction perpendicular to the cutting edge 3 and a substantially semi-cylindrical raised portion 9b are alternately provided, and the vicinity of the cutting edge 3 at the raised portion 9b as shown in FIG. Was cut off diagonally to form a small edge 9. In this way, the cutting edge 3 is provided with an uneven shape, and the chip is divided into narrow pieces by the small edge 9, so that the chip is easily curled and the chip processing becomes smooth. In particular, even when the amount of cut is sharply increased, such as when machining the step corner of the shaft, since the plurality of raised portions 9b are arranged side by side with one cutting edge 3, the cutting edge 5 of the nose portion 4 is cut.
And the entire chip is well curled and discharged stably.

The width of the raised portion 9b is 1 m
It is preferably in the range of m to 3 mm. The raised portion 9
If the width of b is less than 1 mm, the strength of the raised portion 9b and the adjacent portion may be significantly reduced, while
If it is larger than 3 mm, some of the chips are unlikely to sink between the protruding portions 9b, and rather the chips will run over the protruding portions 9b as a whole. In addition, there is a possibility that the auxiliary projection effect in the case of the pressing process may be insufficient.

The present invention is not limited to the above-described embodiment, and can be in any form without departing from the object of the invention.

[0022]

EXAMPLE 1 In the cutting insert 10 shown in FIGS.
Samples having different distances F as shown in Table 1 were prepared, and processing tests were performed under the following cutting conditions, and the results were visually evaluated. Table 1 shows the results.

[0023]

[Table 1]

Cutting conditions V = 400 m / min d = 0.3 mm f = 0.7 mm / rev Work material: SPHE (JIS) Tool shape: TNMG160408 Cutting fluid: yes As is clear from Table 1, the distance F is 0.3-0.7
In the case of the above, the chips were finely divided and in a good processing state. On the other hand, when the distance F is less than 0.3 mm,
Cutting resistance increased, and the cutting edge 5 was oxidized and worn. In addition, when the thickness exceeded 0.7 mm, the chips were elongated and entangled. From the above results, the distance F was 0.6
It turned out that it is preferable that it is -1.0 mm.

Example 2 In the above-mentioned cutting insert 10, samples in which the steps E were different from each other as shown in Table 2 were prepared, and a processing test was performed under the following cutting conditions, and the result was evaluated with the naked eye.
Table 2 shows the results.

[0026]

[Table 2]

As is evident from Table 2, when the step E was 0.01 to 0.1, the chips were finely divided and a good machining state was obtained. On the other hand, when the step E is 0.0
When 1 is less than mm, the cutting resistance was increased, and the cutting edge 5 was oxidized and worn. In addition, when the thickness exceeds 0.1 mm, the chips are elongated and entangled. From the above results, it was found that the step E was preferably 0.01 to 0.1 mm.

Example 3 In the above-mentioned cutting insert 10, samples were prepared with different rake angles α ° as shown in Table 3, and processing tests were carried out under the following cutting conditions, and the results were visually evaluated. Table 3 shows the results.

[0029]

[Table 3]

As is clear from Table 3, when the rake angle was 2 ° to 13 °, the chips were finely divided and a good machining state was obtained. On the other hand, when the rake angle was less than 2 °, the cutting resistance increased, and the cutting edge 5 was oxidized and worn. In the case of more than 13 °, the chips were elongated and entangled. From the above results, it was found that the rake angle α ° is preferably 2 ° to 13 °.

Example 4 In the above-mentioned cutting insert 10, samples were prepared in which the downward angle β ° of the cutting edge 3 was different from each other as shown in Table 4, and a processing test was performed under the following cutting conditions. Was evaluated. Table 4 shows the results.

[0032]

[Table 4]

As is apparent from Table 3, when the descending angle was 4 ° to 8 °, the chips were finely divided and the working state was good. On the other hand, when the rake angle was less than 4 °, the discharge direction became unstable and chips were entangled. In addition, when the angle was more than 8 °, the chips were elongated and entangled. From the above results, it was found that the descending angle β ° is preferably 4 ° to 8 ° from the above results.

[0034]

As described above, according to the cutting insert of the present invention, the chips from the cutting edge surely hit the groove bottom of the shallow breaker groove, bounced slidably and then hit the breaker projection, and the breaker groove was hit. Since it is narrow, it curls spirally with a small radius of curvature without being decelerated. At this time,
As described above, since the cutting edge is lowered at a fixed angle to both sides from the tip of the cutting edge of the nose portion, the chip flows smoothly toward the breaker projection in both the pulling process and the pushing process. Are easily cut, and the cutting resistance does not increase. Further, since the rake angle of the breaker groove is small, the edge strength is high. Therefore, in the cutting insert of the present invention, even in the case of cutting such as hot-rolled soft iron or cold-rolled plate, the chip reliably hits the breaker projection, curls and is stably discharged, and furthermore, the corner of the step portion is discharged. Even when the cutting amount changes abruptly, for example, when processing a part, an excellent effect of favorably processing chips is exhibited.

[Brief description of the drawings]

FIG. 1 is a top view of a cutting insert of the present invention.

FIG. 2 is a side view of the cutting insert as viewed in the direction of arrow C in FIG. 1;

FIG. 3 is a sectional view taken along line BB of FIG. 1;

FIG. 4 is an enlarged view of a region A in FIG. 1;

FIG. 5 is a sectional view taken along line DD of FIG. 1;

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 cutting insert 1 rake face 2 flank 3 cutting edge 4 nose portion 5 cutting edge tip 6 breaker groove 7 seating surface 8 breaker protrusion 9 small edge 9a groove 9b ridge 11 rising starting point A area

Claims (1)

[Claims] 1. A cutting insert, wherein a cutting edge is formed on a ridge between a rake face and a flank and a breaker projection is formed at a central portion in a breaker groove of a nose part. And the step E between the breaker groove and
1 to 0.1 mm, the distance F from the cutting edge to the starting point of the breaker projection is 0.3 to 0.7 mm,
Rake angle α from the cutting edge to the breaker groove
From 2 ° to 13 °, the downward angle β of the cutting blade from the tip of the cutting blade.
The cutting insert is characterized in that the angle is 4 to 8 °.