JPH1148006A - Throw-away tip - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a versatile breaker of a throw-away tip applicable to a wide range of cutting and feed, and excellent especially in shallow cutting. SOLUTION: A breaker groove 7 is provided along a cutting edge 6 on the upper face 2 of a tip 1. The breaker groove 7 is formed in a corner part 3a due to a projection 8 extending from the center part. The tip of the projection 8 presents a recess shape surrounding the corner part in a plane view. The breaker groove 7 is formed of an inclined surface which becomes lower in the direction away from the corner cutting edge, and a stand-up surface 9 standing up from the bottom part toward the projection 8.

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 used for turning, particularly to a breaker shape.

[0002]

2. Description of the Related Art Conventionally, in a throw-away insert which is detachably mounted on a turning tool such as a cutting tool, various breaker shapes for chip control have been adopted. Among them, there are materials that are specialized to limit the work material, processing method, cutting conditions, etc. and demonstrate excellent chip disposal performance within that range, while targeting general steel materials such as carbon steel There is a chip breaker designed so that it can be applied over a wide range of cutting conditions and intended for general use.

In order to make the breaker highly versatile,
Conventionally, the shape of a breaker is basically formed by a combination of grooves, protrusions, and depressions, and has been improved while changing its arrangement, angle, size, and the like. A particular annoyance to developers when trying to design a versatile breaker is chip handling at shallow cuts and small feeds, which are difficult to solve. This is because, in the case described above, the chips are thin or thin and have elasticity, so that the chips are not restrained by the breaker and go over the breaker wall, resulting in poor chip treatment.

In order to solve this problem, a wall surface which is an obstacle to chip outflow is generally arranged near the corner. In particular, a curved projection extending toward the tip of the corner is often provided. Japanese Patent Application Laid-Open No. 9-38
807 and JP-A-9-38808.

[0005]

An object of the present invention is also to provide a breaker having excellent versatility.
In particular, the emphasis is on solving chips when the depth of cut is shallow as described above. In a shallow cut, if a breaker capable of processing chips in a wide range from a small feed to a large feed is used, braking will be given priority, and chips will be finely divided,
Excessive cutting force due to excessively effective breaker and occurrence of chatter vibration may cause problems such as shortage of the cutting edge due to lack of the cutting edge and continuation of cutting.

Therefore, the present invention changes the conventional concept of a curved projection extending toward the tip of a corner to improve the breaker performance and adversely affect other cutting performances. Even if the depth of cut is shallower than before, that is, specifically, even if the depth of cut is as small as about 0.5 mm, a wide feed range, that is, specifically, 0.2 mm /
It is an object of the present invention to provide a breaker that works effectively in a feed range of rev to 0.6 mm / rev.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above problems, and has a polygonal flat plate-shaped chip body in which at least a top edge is formed with a cutting edge to form a rake face. In a throw-away chip, a breaker groove is formed on the upper surface along the cutting blade, and the breaker groove is formed at a corner portion by a projection on a boss surface extending from a central portion. The groove is formed by an inclined surface that becomes lower as it goes away from the corner cutting edge, and an upright surface that rises from the bottom toward the projection, and the tip of the projection has a concave shape that surrounds the corner in plan view. It is characterized by being. The upright surface that rises toward the projection has a longest upright surface that protrudes from two apexes of the projection having a concave shape in a plan view and is close to the cutting edge, and the upright angle of the portion is 10 ° to 30 °. Is characterized in that:

The corner radius of the throw-away tip is standardized, and most of the corner radius is 0.4 mm to 1.6 mm. Thus, for a shallow cut of 0.5 mm, most, and possibly all, of the chips will be generated by the corner cutting edges. In the case of a corner cutting edge having an arc shape, the contact state changes due to a slight change in the cutting depth, so that the chip discharge direction also changes. The appearance also changes depending on the size of the corner radius used. The breaker wall formed so as to surround the corner portion as described above, and the inclined surface formed so as to be lower toward the breaker wall from the corner cutting edge, form a breaker groove that is concave as if in a mortar shape. As a result, the chips are attracted into the breaker groove, and effectively act as a breaker wall without being influenced by the fluctuation of the chip outflow direction, so that a wide chip processing range can be obtained. Further, such a configuration enables chip processing in a wide feed range even for a shallower cut than before.

[0009] On the other hand, the problem of the indexable insert of the present invention is that it is a highly versatile breaker.
Chip control must be performed even at moderate cuts. Therefore, it is necessary to provide a breaker groove along a ridgeline serving as a cutting edge, and to avoid forcibly deforming outflowing chips with a projection at the time of shallow cutting provided so as to surround the corner portion. For this reason, the upright angle of the upright surface rising from the vicinity of the cutting edge toward the top of the projection is set to 10 ° to 30 ° so that the chip inducing action at the time of shallow cutting and the breaker action at the time of middle cutting are secured. This is to prevent braking from becoming excessive.

[0010]

Next, an embodiment of the present invention will be described with reference to the drawings. 1 to 5, FIG. 1 is an enlarged perspective view of a corner portion of a throw-away tip (hereinafter referred to as a tip) of the present invention, FIG. 2 is a plan view of the entire tip, FIG. 3 is a side view of FIG. 2, and FIG. 5 is a sectional view taken along line AA of FIG. 2, and FIG. 5 is a sectional view taken along line BB of FIG. This chip 1
Is a rhombic flat plate as an example. In the case of a rhombic chip, of the four corner portions 3a and 3b on the upper surface 2 serving as a rake surface, a corner portion 3a having a sharp apex angle is provided.
Are generally used corners, so the present invention also mainly relates to the corner portion 3a.

At the center of the chip 1, a mounting hole 4 used for mounting on a cutting tool penetrates, and a boss surface 5 is provided around the mounting hole 4 on the upper surface 1. When the chip 1 is a negative chip, since the chip 1 is turned upside down and the upper surface is used as the lower surface, the boss surface 5 plays a role of a seating surface facing the chip seat of the cutting tool. Therefore, the boss surface 5 is formed flat to secure the stability of seating. The boss surface 5
Although it is divided into a central part of the cutting edge and a corner part,
The boss surface 5 isolated in the shape of an island at the center of the cutting blade is provided as a seating surface, and has little function as a breaker.

The ridge line at the outer edge of the upper surface 2 becomes the cutting edge 6, and the boss surface 5 is disposed slightly apart from the cutting edge 6.
Therefore, the space between the boss surface 5 and the cutting edge 6 becomes the breaker groove 7. Further, the cutting blade 6 is formed so as to be slightly lower than the boss surface 5 so that when the tip 1 is turned over and comes to the seating surface side, the cutting blade 6 is lifted from the seating surface so that the chip 1 comes into contact with the chip seat. Prevent the resulting defects.

In the corner portion 3a, the boss surface 5 has a projection 8 extending from the center to the corner, and a skirt that becomes gradually lower at the outer periphery of the projection 8. When viewed from the breaker groove 7, the base becomes the upright surface 9. The tip of the projection 8 has a curved surface surrounding the corner in FIG. 2 which is a plan view. Therefore, the tip end of the projection 8 forms the tip projection 8a which is divided into two, and the skirt extends from the top of the tip projection 8a near the cutting blade 6. If the overhanging surface of the base is the upright surface 9a, the upright angle α is preferably α = 10 ° or more as shown in FIG.
Be at 30 °. The upright angle of the upright surface 9 at the other portion is changed so that the farther from the upright surface 9a becomes gradually larger than the above-mentioned upright angle α.

Referring to the breaker groove 7, first, the cutting edge 6
Is provided with a land 10 at the inner edge thereof. Although flat lands are employed in this embodiment, there are other types of negative lands and positive lands depending on the rake angle of the lands, and there are also sharp edges without lands. These are appropriately selected according to required cutting performance such as chipping resistance and cutting resistance. On the inner side of the land 10, an inclined surface 11, which is gradually lowered inward, is formed, and is connected to the boss surface 5 by the upright surfaces 9, 9a rising from the bottom.

With the above-described configuration, chips are attracted to the mortar-shaped recess formed in the corner with respect to a cut that is shallower than the position where the upright surface 9a is provided, that is, a cut that can be said to be a finish cut. At the same time, the chips that have been once attracted are restrained by the upright surface 9 and undergo a deforming action, so that the chip flow is stabilized, thereby improving the chip processing. In the present invention, the point at which the upright surface 9a starts to erect is determined by the distance b from the tangent at the corner, as viewed along the cutting edge, in order to perform excellent chip control even at a shallower cut than the conventional general-purpose breaker. However, it is preferable to set it between 1 and 3 times the size of the corner radius.

Next, in a notch slightly exceeding the position of the upright surface 9a, that is, in a light cutting area, since the upright start point of the upright surface 9a is close to the cutting edge 6, if the upright angle α is too large. Chip clogging and chattering are likely to occur, causing chip breakage. Therefore, the chips are caused to flow on the upright surface 9a. However, if the inclination is too gentle, the chips flow without deformation and do not serve as a breaker. It is effective that the upright angle α of the upright surface 9a is 10 ° to 30 ° in addition to the above-described chip inducing at the time of the shallow cutting, and also as a breaker at the time of light cutting.

Further, as the depth of cut becomes deeper, that is, a cut which can be called medium cutting, as the distance from the corner increases, the upright surface 9 serving as the base of the projection 8 is formed so as to be farther from the cutting blade 6 to form a breaker. The pocket as the groove 7 is widened. Giving the chip a strong deformation not only affects the tool life when the cutting depth is large, but also causes excessive power for a machine such as a lathe. In addition, the circular recess 12 provided only at one place on the boss surface 5 is a mark for identifying a used corner, and has nothing to do with the breaker.

[0018]

As described above, according to the indexable insert of the present invention, the seemingly mortar-shaped dent formed in the corner portion attracts the chips discharged when the depth of the cut is shallow to the dent and to the destination. Due to the restraining action of the rising surface rising up, the chips can flow out stably. In addition, chips can be processed over a wide range of feed. Even if the cut is further deepened, the entire protrusion extending from the central portion to the corner portion acts as a breaker groove,
Chips can be cut without causing chip clogging. Therefore, it is possible to provide a general-purpose breaker that can be widely applied from light cutting to medium cutting.

[Brief description of the drawings]

FIG. 1 is a perspective view of an enlarged corner portion showing one embodiment of a throwaway tip of the present invention.

FIG. 2 is a plan view of the entire throw-away tip shown in FIG.

FIG. 3 is a side view of FIG. 2;

FIG. 4 is a sectional view taken along line AA of FIG. 2;

FIG. 5 is a sectional view taken along the line BB of FIG. 2;

[Explanation of symbols]

 3a, 3b Corner 5 Boss surface 6 Cutting edge 7 Breaker groove 8 Projection 8a Tip projection 9, 9a Standing surface 11 Inclined surface α Standing angle

Claims (2)

[Claims] 1. A chip body having a polygonal flat plate shape has a cutting edge formed on at least an upper surface ridge line, and a breaker groove along the cutting edge is formed on the upper surface which is a rake face. In a throw-away chip in which the breaker groove is formed by a projection on a boss surface extending from a central portion, the breaker groove in the corner portion is
An inclined surface that becomes lower as the distance from the corner cutting edge increases,
A throw-away tip, which is formed by an upright surface rising from the bottom toward the projection, and the tip of the projection has a concave shape surrounding the corner in plan view. 2. The upright surface that stands up toward the projection,
2. The projection according to claim 1, wherein the projection having a concave shape in plan view protrudes near the cutting edge from the two apexes, has a longest standing surface, and has a standing angle of 10 ° to 30 °. 3. Indexable tip.