JP2000153401A - Throwaway tip - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance cutting blade strength, so that cutting chips can be smoothly discharged. SOLUTION: This throwaway tip is formed out of a rake face 12 in an upper surface of a chip main body 10 in rhombus flat plate shape having a seating surface of tool main body in a lower surface, formed with a peripheral surface of the tip main body 10 formed between the seating surface and the upper surface as a flank 13, and formed with a cutting blade B with a corner part in the upper surface of the tip main body 10 serving as a nose part 14 in a ridge line part between the rake face 12 and the flank 13. Here, the cutting blade B is rise up formed along a recessed curve to a tip end of the nose part 14 so as to separate from the seating surface in accordance with approaching the nose part 14, breaker surfaces 16, 20 are provided along a lengthwise direction of the tip main body 10 in the upper surface thereof and in a location interposed by the rake face 12, and a flat surface 15 is formed between the nose part 14 and the breaker surface 16 connected to this nose part 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a throw-away insert, and more particularly, to a throw-away insert having a high cutting edge strength and capable of smoothly discharging chips.

[0002]

2. Description of the Related Art Some throw-away chips are shown in FIGS. 11 and 12, for example. In the figure,
Reference numeral 1 denotes a chip body. The chip body 1 has a rhombic flat plate shape and has a seating surface 3 of a tool body 2 on a lower surface. A rake face 4 is formed on the upper surface of the chip main body 1, and a flank 5 constituting a peripheral surface of the chip main body 1 is formed between the seating surface 3 and the upper surface. A cutting edge 7 having a corner on the upper surface of the chip body 1 as a nose 6 is formed at a ridge line between the rake face 4 and the flank 5.

[0003]

However, in the conventional indexable insert described above, when the workpiece 8 is machined as shown in FIG. When biting, the upper edge of the cutting blade 7 may come into contact with the workpiece 8 over its entire length. In such a case, the contact portion between the cutting blade 7 and the workpiece 8 generally increases, so that the cutting resistance increases. Therefore, it is necessary to take measures such as changing the material of the chip body 1 in order to increase the chip strength, assuming a large load in the initial stage of cutting in which the impact on the cutting blade 7 is large.

[0004] On the other hand, an excessively large force is applied to the chip body 1 depending on the state of chip discharge generated during cutting, and how to control the chip discharge determines the cutting edge strength of the chip. This is a major factor. Therefore, the present invention provides a throw-away tip having a high cutting edge strength and capable of smoothly discharging chips.

[0005]

In order to solve the above problems, according to the present invention, a rake face is formed on an upper surface of a chip body having a polygonal flat plate shape and having a seating surface of a tool body on a lower surface thereof. A peripheral surface of the chip body formed between the upper surface and the upper surface is formed as a flank, and a cutting edge having a nose portion at a corner of the upper surface of the chip body is formed at a ridge line between the rake face and the flank. The indexable insert is characterized in that the cutting edge is formed so as to rise away from the seating surface as it approaches the nose along the concave curve up to the tip of the nose.

[0006] With such a configuration, it is possible to reduce the impact of the cutting blade from the workpiece by gradually cutting the cutting edge into the workpiece in the initial stage of cutting. In addition, the outflow direction of the chips can be controlled by making the cutting blades curved. Also, a rake face is formed on the upper surface of the chip body having a seating surface of the tool body on the lower surface in the shape of a polygonal flat plate, and a peripheral surface of the chip body formed between the seating surface and the upper surface is formed as a flank surface,
In a throwaway tip in which a cutting edge having a corner portion on the upper surface of the tip body as a nose portion is formed at a ridge portion between the rake face and the flank face, the cutting edge moves away from a seating surface as the nose portion approaches the nose portion. The cutting edge of the nose portion is formed parallel to the seating surface of the tip body. With such a configuration, it is possible to reduce the impact of the cutting edge from the workpiece by gradually cutting the cutting edge into the workpiece in the initial stage of cutting.
In addition, the outflow direction of the chips can be controlled by making the cutting blades curved. Further, the cutting edge strength of the nose portion can be increased. Here, in the case where a plurality of breaker surfaces are provided along the longitudinal direction of the chip body on a portion of the upper surface of the chip body between the rake surfaces, the discharge is performed by the plurality of breaker surfaces. The generated chips are reliably provided with a braking effect, thereby being curled and controlled, thereby preventing an increase in cutting resistance due to chip discharge resistance.

In the case where a flat surface is formed between the nose portion and the breaker surface connected to the nose portion, the upper surface of the tip body near the nose portion where a large force acts at the beginning of cutting and the seating surface. The thickness of the tip can be increased, and the cutting edge strength of the tip body can be secured.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. 1 to 6, reference numeral 10 denotes a chip body, and the chip body 10 is integrally formed in a rhombic flat plate shape from a hard material such as cemented carbide, and has a seating surface of a tool body (not shown) on a lower surface. 11 is provided. A rake surface 12 is formed on the upper surface of the chip body 10, and a seating surface 11 is formed.
A flank 13 constituting the peripheral surface of the chip body 10 is formed between the upper surface and the upper surface. And these rake faces 12
A sharp cutting edge B (positive tip) having a nose portion 14 at a corner on the upper surface of the tip body 1 is formed at a ridge line between the flank 13 and the flank 13.

In the vicinity of the nose portion 14, a flat surface 15 is provided between the rake surfaces 12 so as to be continuous therewith.
The flat surface 15 is formed so as to be separated from the seating surface 11 so that the thickness of the chip main body 10 becomes thicker as approaching the nose portion 14.
The strength of the nearby cutting edge is ensured. As shown in FIGS. 7 to 9, the top surface of the chip body 10, which is located between the rake faces 12, is connected to the flat surface 15 and extends along the longitudinal direction of the chip body 1.
6 are provided. The breaker surface 16 has a concave portion 19 formed by a downwardly concave curved surface (hereinafter, simply referred to as a curved surface) 17 connected to the flat surface 15 via a valley P, and a curved surface 18 connected thereto. ing.

The breaker surface 16 is further provided with a breaker surface 20 having the same structure as the above. The breaker surface 20 has a curved surface 22 forming a valley 21 with the curved surface 18 and will be described later. It has a ridge 24 composed of a flat surface 23. The ridge 24 is formed higher than the ridge 19. And the above-mentioned breaker surface 1
As described above, reference numerals 6 and 20 are also formed on the other nose portion 14 side, and the through holes of the clamp screw for attaching the throwaway tip to the tool body (not shown) are formed on the flat surface 23 formed between the respective breaker surfaces 20. 25 are formed. Here, the tip body 1 is positioned with respect to the center of the insertion hole 25.
Numeral 0 is rotationally symmetric, so that two nose portions 14 provided on a diagonal line and a cutting edge B connected to the nose portions 14 are corner-changed, so that a total of two reusable times are possible.

Therefore, although the rake face 12 is discontinuous at the position corresponding to the peak 19 as shown in FIGS. 1 to 3, the flat face 15 and the curved faces 17 and 18 of the breaker face 16 are formed. In the part adjacent to the cutting edge B, the tip body 10 is curved so as to rise linearly toward the cutting blade B and rise upward in the longitudinal direction of the chip body 10. In addition, the portion adjacent to the 16 curved surfaces 22 and the flat surface 23 of the breaker surface is formed as a plane that rises obliquely toward the cutting blade B.

As shown in FIGS. 4 to 6, the cutting blade B extends from the portion corresponding to the center of the insertion hole 25 to the valley 2.
No. 1 is formed in a linear shape whose distance from the seating surface 11 does not change, and at portions corresponding to the valleys 21, the peaks 19, and the valleys P, they are formed to rise slightly from the seating surface 11 and to go down. Further, in a portion extending from the valley P to the nose portion 14, the nose portion 14 is formed to rise up to the tip of the nose portion 14 along a concave curve so as to be further away from the seating surface 11 as approaching the nose portion 14. In addition, the cutting blade B is formed so as to rise up along a concave curve so as to largely separate from the seating surface 11 as approaching the nose portion 14,
The tip portion of the nose portion 14 may have a shape formed parallel to the seating surface 11 of the chip body 10. By doing so, the cutting edge strength of the nose portion 14 can be increased.

According to the above-described embodiment, since the cutting edge B is formed so as to rise away from the seating surface 11 along the concave curve as it approaches the nose portion 14, the cutting edge B is covered in the initial stage of cutting. As a result, the impact of the cutting edge B on the material to be cut at the time of the initial cutting is reduced, and the cutting edge B can be eliminated without loss and smooth cutting can be performed. Therefore, cutting force can be reduced without exerting an excessive force on the cutting blade B. As a result, it is not necessary to take measures such as enlarging the chip body 10 to increase the cutting strength.

An upper surface of the chip body 10 and a portion sandwiched between the rake faces 12 are provided along the chip discharging direction along the chip discharging direction.
Since the two breaker surfaces 16 and 20 are provided, the chips discharged by cutting can
6. Specifically, the valley P becomes the starting point of the curl, is curled and cut by the curved surface 17, and the braking effect is reliably provided. Thus, the chips can be smoothly discharged, and an increase in the cutting resistance due to the chip discharge resistance can be prevented. Therefore, coupled with the reduction in cutting resistance due to the shape of the cutting edge B, the cutting resistance as a whole of the chip body 10 can be significantly reduced, and the substantial cutting edge strength can be increased.

In this case, even if the chips get over the breaker surface 16 due to the cutting speed or the like, the chips are surely braked by the breaker surface 20 having the ridge portion 24 higher than the breaker surface 16. Specifically, the curving is performed on the curved surface 22 starting from the valley 21 and cut. Therefore, the reliability of the breaking effect on chips can be enhanced by the two breaker surfaces 16 and 20. And the nose part 14
The flat surface 15 is formed between the breaker surface 16 and the breaker surface 16 connected thereto, so that the breaker surface is smaller than when the breaker surface 16 and the nose portion 14 are formed as a curved surface. The thickness of the chip body 10 between the nose portion 16 and the nose portion 14 can be increased,
Therefore, a large force acts during cutting, and the strength of the cutting edge near the nose portion 14, which is disadvantageous in strength, can be sufficiently secured.

Next, FIG. 10 shows another embodiment of the present invention. This embodiment is the same as the above embodiment in the basic configuration, but the flatness of the rhombus shape in plan view is smaller than that of the above embodiment. In this embodiment, the same parts as those of the above-described embodiment are denoted by the same reference numerals, and description thereof will be omitted. Even if the chip bodies having different sizes are used, the flat surface 15, the breaker surfaces 16, 20, the rake surface 12, etc. are adopted as described above, the cutting edge strength is high, and chips can be discharged smoothly. Becomes possible.

[0017]

As described above, according to the present invention, the cutting edge is formed so as to rise from the seating surface to the tip of the nose portion along the concave curve as the cutting edge approaches the nose portion. In particular, the cutting edge can bite into the material to be cut in the initial stage of cutting, and the impact of the cutting edge from the material to be cut can be reduced. Therefore, the loss of the cutting edge at the beginning of cutting can be suppressed. As a result, there is an effect that the cutting edge can be substantially increased without excessive force acting on the cutting edge. Here, when the cutting edge of the nose portion is formed parallel to the seating surface of the tip body, the cutting edge strength of the nose portion can be further increased. Further, in the case where a plurality of breaker surfaces are provided along the longitudinal direction of the chip body on a portion of the upper surface of the chip body, which is sandwiched between the rake faces, by the plurality of breaker surfaces,
The discharged chips are surely given a braking effect,
As a result, it is curled and cut, so that an increase in cutting resistance due to chip discharge resistance can be prevented, and there is an effect that chips can be discharged smoothly.

Since a flat surface is formed between the nose portion and the breaker surface connected thereto, the flat surface is formed as compared with a case where the space between the breaker surface and the nose portion is formed as a curved surface. In addition, the thickness between the upper surface of the tip body and the seating surface in the vicinity of the nose portion where a large force acts during cutting can be increased. Therefore, since the required strength of the tip body can be secured, there is an effect that the strength of the cutting edge near the nose portion, which is disadvantageous in strength, can be sufficiently secured.

[Brief description of the drawings]

FIG. 1 is a perspective view of an embodiment of the present invention.

FIG. 2 is a perspective view in which a portion along the line AA in FIG. 1 is cut away.

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

FIG. 4 is a plan view of FIG. 1;

FIG. 5 is a front view of FIG. 4;

FIG. 6 is a side view of FIG.

FIG. 7 is a sectional view taken along the line DD of FIG. 4;

FIG. 8 is a sectional view taken along the line EE in FIG. 4;

FIG. 9 is a sectional view taken along line FF of FIG. 4;

FIG. 10 is a plan view of another embodiment of the present invention.

FIG. 11 is a plan view of a conventional technique.

FIG. 12 is a front view of the prior art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Chip body 11 Seating surface 12 Rake surface 13 Flank 14 Nose part 15 Flat surface 16 Breaker surface 20 Breaker surface B Cutting blade

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Hiroyuki Takahashi 1511 Furamagi, Ishishita-cho, Yuki-gun, Ibaraki Pref. Mitsubishi Materials Corporation Tsukuba Works F-term (reference)

Claims (4)

[Claims] 1. A rake face is formed on an upper surface of a chip body having a polygonal flat plate shape and having a seating surface of a tool body on a lower surface, and a peripheral surface of the chip body formed between the seating surface and the upper surface serves as a flank surface. In a throwaway chip formed and formed with a cutting edge having a corner portion on the upper surface of the chip body as a nose at a ridge line between the rake face and the flank, a seating surface as the cutting edge approaches the nose. A throw-away tip characterized in that it is formed upright along a concave curve up to the tip of the nose part away from the tip. 2. A rake face is formed on an upper surface of a chip body having a polygonal flat plate shape and having a seating surface of a tool body on a lower surface, and a peripheral surface of the chip body formed between the seating surface and the upper surface serves as a flank surface. In a throw-away chip formed and formed with a cutting edge having a nose portion at a corner portion of the upper surface of the chip body at a ridge line between the rake face and the flank face, a seating surface as the cutting edge approaches the nose portion. A throw-away tip formed upright along a concave curve away from the tip, the cutting edge of the nose part being formed parallel to the seating surface of the tip body. 3. The chip body according to claim 1, wherein a plurality of breaker surfaces are provided along a longitudinal direction of the chip body at a portion between the rake faces on the upper surface of the chip body. Item 3. The throw away tip according to Item 2. 4. The indexable insert according to claim 1, wherein a flat surface is formed between the nose portion and a breaker surface connected to the nose portion.