JP2002126915A - Throw-away tip - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform excellent processing of chips on a wide cutting condition. SOLUTION: A nose part 3 is formed at a corner 2a of a tip body 2 and cutting blades 6 connected to a nose part 3 are formed at two cross ridge lines consisting of a pair of adjoining sides 4 of the tip body 2 with a nose part 2 nipped therebetween. On an upper surface 5, a spherical dot breaker 8 protruding approximately in a spherical surface state to a comparatively high level is formed in a position separated inwardly from the nose part 3 and the cutting blade 6 and on approximate the bisector of the nose part 3. On the upper surface 5, a small dot breaker 9 extending in a direction approximately paralleling the bisector and protruding in a comparatively low and an approximate column peripheral surface shape from the upper surface 5 is formed on the cutting blade 6 side of the spherical dot breaker 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 mounted on a tool body such as a cutting tool for cutting a workpiece.

[0002]

2. Description of the Related Art There are various types of throw-away tips (hereinafter simply referred to as tips) depending on the application. For example, a nose portion is formed at a corner of a chip body having a polygonal flat plate shape, and two intersections formed by each of a pair of adjacent side surfaces of the chip body sandwiching the nose portion and the upper surface of the chip body connected to the nose portion. There is a chip with a cutting edge formed on the ridge. In such a chip, for example, on the upper surface forming a rake surface, on a substantially bisector of a nose portion,
Spherical dots are provided that protrude from the upper surface into a substantially spherical shape.
When such a chip is mounted on the tool body to cut the work material, the chips shaved from the work material by the cutting blade travel along the rake face, collide with the spherical dots and change the flowing direction. Changed and bent, cut into appropriate lengths and discharged.

[0003]

In the above-mentioned conventional chip, when cutting with low cutting depth, chips shaved from the work material by the cutting blade may not reach the spherical dots. In this case, the chips could not be sufficiently bent and divided, and the chips could not be satisfactorily processed. As an improved version of this chip, Japanese Utility Model Laid-Open No. 1-101706 discloses a chip provided with a first projection in the vicinity of a nose portion of a rake face. With this chip, even when cutting with low cutting depth, the first projection formed in the vicinity of the nose allows the chips to be sufficiently bent, so that when cutting with low cutting depth and low feed rate is performed, Chip processing performance can be improved. However, when the insert is configured in this manner, the chip and the cutting edge are not aligned with each other during high-cut or high-feed cutting.
Therefore, it becomes difficult to perform good cutting because the cutting resistance is increased and clogging easily occurs between the protrusions. Therefore, there is a problem that the chip disposability is inferior when performing cutting in which the cutting depth changes, such as copying cutting and lifting cutting.

In addition, in Japanese Patent Application Laid-Open No. Hei 6-79505, a conventional chip breaking rib is provided inside each corner, and the rib is located near the root of a slope descending from the nose toward the corner. 2 shows a chip in which a pair of elongated projections are symmetrically arranged with respect to a bisector of a corner. With this insert, long projections are used for light cutting (low cutting and low feed cutting), and ribs for medium cutting (high cutting and high feed) cutting. Effectively treats chips. But,
When high-cutting and low-feed cutting is performed, as in the case of pull-up cutting of the end face, thin chips having a long length along the cutting edge are generated. Since the chips are generated so as to flow toward the base end of the tool, the chips are difficult to reach the long projections and ribs, and the chips cannot be bent sufficiently. In addition, the long projections are arranged at a distance from the corners and the cutting blades connected to the corners.When high-speed cutting is performed, the chips are likely to be elongated, and the chips are likely to be long. Since the long projections are rubbed, crater wear occurs at these portions, and the long projections are liable to be worn out. As the cutting is repeated, the long dots may gradually stop functioning.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a chip capable of favorably processing chips under a wide range of cutting conditions.

[0006]

In order to achieve the above object, in a chip according to the present invention, a nose portion is formed at a corner of a chip body having a polygonal flat plate shape.
A cutting edge is formed on at least one of two intersecting ridges formed by each of a pair of adjacent side surfaces of the chip body sandwiching the nose portion and the upper surface of the chip body connected to the nose portion, and the rake surface is formed. On the upper surface, on a roughly bisector of the nose portion, in a throwaway tip provided with spherical dots protruding in a substantially spherical shape from the upper surface, the spherical dots are separated inward from the nose portion and the cutting edge. The small dots that extend in a direction substantially parallel to the approximately bisector and protrude from the upper surface into a substantially cylindrical peripheral surface shape are provided on the upper surface on the cutting edge side of the spherical dots. It is characterized by being provided.

In the chip configured as described above,
When cutting at a low depth of cut, chips shaved from the work material by the cutting edge of the nose portion collide with small dots provided on the cutting edge side of the spherical dots, are bent, separated, and discharged. At this time, since the chips are bent by small dots closer to the cutting edge than the spherical dots, the chips are bent with a smaller curl diameter as compared with the case where the chips are bent by the spherical dots, and the chips are shorter and more easily broken. Similarly, when high-cut and low-feed end faces are lifted and cut, the chips shaved from the work material by the cutting blade collide with small dots closer to the cutting edge than spherical dots and bend. Being divided,
Is discharged. Here, the small dots have a substantially cylindrical peripheral surface shape, and the chips come into line contact with each other, so that the progress of partial wear of the small dots is suppressed and stable chip processing becomes possible. Since the small dots have a substantially cylindrical peripheral surface shape extending in a direction substantially parallel to the bisector of the nose, stable chip processing can be performed regardless of the cutting depth. Furthermore, by providing the small dots on the cutting edge side of the spherical dots at least partially on one side, the root portion of the spherical dots on the cutting edge side is protected, and wear is less likely to occur. In addition, when cutting at a high depth of cut, chips shaved off by the cutting blades are bent by colliding with small dots and colliding with spherical dots, and are cut into appropriate lengths and discharged. The spherical dots are provided separately from the nose and the cutting blade, and the chips are
Since it collides with the spherical dot at a predetermined distance after being cut off from the work material by the cutting blade, the chip is hardly clogged and the cutting resistance is reduced.

In this chip, assuming that the radius of curvature of the substantially spherical surface of the spherical dot is R1 and the radius of curvature of the substantially cylindrical peripheral surface of the small dot is R2, when the ratio R2 / R1 is smaller than 0.2, Also, the small dots are too small and the chips easily pass over the small dots, and the effect of cutting the chips by the small dots is weakened. On the other hand, when R2 / R1 is larger than 0.8, the small dots are too large, and the chips do not easily pass over the small dots more than necessary, and the chips are easily clogged. For this reason, the ratio of the radius of curvature R1 of the substantially spherical surface of the spherical dot to the radius of curvature R2 of the substantially cylindrical peripheral surface of the small dot is:
It is preferable to be in the range of 0.2 ≦ R2 / R1 ≦ 0.8. In this chip, the maximum height of the small dots from the upper surface is set lower than the maximum height of the spherical dots from the upper surface. Here, the difference H between these heights is
If the diameter is smaller than 0.1 mm, the chips that have survived the small dots can easily survive the spherical dots, so that the effect of the spherical dots is almost eliminated. H is 0.6mm
If the diameter is larger than the above, the traveling direction of the chip that has passed over the small dot can be changed more rapidly than necessary by the spherical dot, so that the effect of the spherical dot becomes too strong and the chip is easily clogged. Therefore, the difference H between the maximum height of the spherical dots and the maximum height of the small dots is 0.1 mm ≦
It is desirable to set the range of H ≦ 0.6 mm.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a throw-away tip according to the present invention will be described below with reference to FIGS. 1 is a plan view showing the shape of the throw-away tip according to the present embodiment, FIG. 2A is a sectional view taken along the line AA of FIG. 1, and FIG. 2B is a sectional view taken along the line BB of FIG. FIG. 3, FIG. 3 and FIG. 4 are views showing the state of processing of chips by the throw-away tip according to the present embodiment. As shown in FIG. 1, a throw-away tip 1 (hereinafter simply referred to as a tip) is formed by bending a tip main body 2 so that a side surface of a substantially triangular flat plate is projected outward at an intermediate position. It has a hexagonal flat plate shape. A nose portion 3 is formed at the acute corner 2 a of the chip body 2, and each of a pair of adjacent side surfaces 4 of the chip body 2 sandwiching the nose portion 3 and the chip body 2 connected to the nose portion 3 are formed. Upper surface 5
The cutting edge 6 is formed at the two intersecting ridges between the two. A land 11 is formed on the upper surface 5 over the entire length of the cutting blade 6 so as to be continuous with the cutting blade 6. Here, in the present embodiment, the chip 1 is a negative chip. The tip 1 has a bolt insertion hole 7 extending from the center of the upper surface 5 forming a rake surface to the lower surface forming a seating surface, and the seating surface is brought into contact with a chip mounting seat of a tool body (not shown). In this state, it is mounted on the tool body by bolts inserted into the bolt insertion holes 7.

[0010] On the upper surface 5, on a substantially bisector of the nose portion 3, at a position spaced inward from the nose portion 3 and the cutting blade 6,
A spherical dot breaker 8 which is relatively high and protrudes in a substantially spherical shape from the upper surface 5 is formed. On the cutting blade 6 side of the spherical dot breaker 8, the spherical dot breaker 8 extends in a direction substantially parallel to the bisector, and is compared with the upper surface 5. A small dot breaker 9 protruding in a substantially cylindrical peripheral surface shape is formed. In the present embodiment, the small dot breaker 9 includes a plurality of substantially cylindrical peripheral surface portions 9a forming substantially cylindrical peripheral surfaces.
Are arranged along the edge of the spherical dot breaker 8 so that one side thereof overlaps with the spherical dot breaker 8, and substantially spherical portions 9 b forming substantially spherical surfaces at both ends thereof, respectively.
(Not limited to this, the small dot breaker 9 may be curved along the edge of the spherical dot breaker 8, and may be formed by a single substantially cylindrical peripheral surface having both ends formed into substantially spherical surfaces.) May be configured). Here, the radius of curvature of the substantially spherical surface of the spherical dot breaker 8 is R1, and the small dot breaker 9 is
Let R2 be the radius of curvature of the substantially cylindrical peripheral surface of R
2 / R1 is in the range of 0.2 ≦ R2 / R1 ≦ 0.8, and in the present embodiment, R2 / R1 = 0.3. The maximum height of the spherical dot breaker 8 from the lowest part of the upper surface 5 is D1 (mm), the maximum height of the small dot breaker 9 is D2 (mm), and the difference between D1 and D2 is H (mm). ), H is 0.1 mm ≦ H
≦ 0.6 mm, and in the present embodiment, D1 = 0.32 mm, D2 = 0.12 mm, and H =
0.2 mm. An island-shaped breaker 10 is formed at a position further away from the nose portion 3 and the cutting edge 6 than the spherical dot breaker 8 and the small dot breaker 9.

When using the chip 1 constructed as described above, one of the cutting blades 6 is used as shown in FIG. 3 in a state where the seating surface is mounted and fixed on a chip mounting seat of a tool body (not shown). The work material W is cut by the nose portion 3 and the cutting edge 6 which forms a ridge connected to the nose portion 3. Then, when low cutting and low feed cutting are performed, the chips K cut from the work material W by the cutting blades 6 of the nose portion 3 pass over the lands 11 as shown by solid lines in FIG. And a small dot breaker 9 provided on the side of the cutting edge 6 used for cutting the spherical dot breaker 8.
It is bent by collision with, and is separated and discharged. At this time, since the chip K is bent by the small dot breaker 9 closer to the cutting blade 6 used for cutting than the spherical dot breaker 8, the chip K has a smaller curl diameter as compared with the case where the chip K is bent by the spherical dot breaker 8. The chips K are bent, and the chips K are shorter and more easily broken.

Similarly, in the case where a high-cut and low-feed end face portion is lifted and cut, as shown in FIG. 4, the chip K cut from the work material W by the cutting blade 6 is also used.
Travels along the upper surface 5 over the land 11, collides with the small dot breaker 9 and is bent, separated, and discharged. Here, the small dot breaker 9 has a cylindrical peripheral surface shape, and the chips K come into line contact, so that the progress of partial wear of the small dot breaker 9 is suppressed.
Further, since the spherical portion 9b is formed at the end of the small dot breaker 9, the end of the small dot breaker 9 acts to bend the chips K in the same manner as the spherical dot breaker. Since the small dot breaker 9 has a cylindrical peripheral shape extending in a direction substantially parallel to the bisector of the nose portion 3, stable chip processing can be performed regardless of the cutting depth.

Further, when high cutting and high feed cutting is performed, the chips K shaved by the cutting blades 6 travel over the lands 11 and travel along the upper surface 5 as shown by broken lines in FIG. The small dot breaker 9 which rises relatively low from the upper surface 5 gets over, and collides with the spherical dot breaker 8 which rises relatively high from the upper surface 5 to be bent, cut into an appropriate length, and discharged. In this chip 1, the spherical dot breaker 8 is provided apart from the nose portion 3 and the cutting edge 6, and the chip K removes the workpiece W by the cutting edge 6.
Since it collides with the spherical dot breaker 8 at a predetermined distance after being scraped off from the chip, the chip K is less likely to be clogged and cutting resistance is reduced. When the high-cut and high-feed cutting is performed as described above, the chips K pass over the small dot breakers 9 and are bent mainly by the spherical dot breakers 8, so that the damage of the small dot breakers 9 is suppressed. . Furthermore, since the small dot breaker 9 is provided on the cutting edge 6 side of the spherical dot breaker 8 so as to overlap one side, the root portion of the spherical dot breaker 8 on the cutting edge 6 side is protected, and wear is reduced. Less likely to occur. Here, since the small dot breaker 9 has a configuration in which a plurality of cylindrical peripheral surface portions 9a are connected and arranged along the edge of the spherical dot breaker 8, the positional relationship with the spherical dot breaker 8 over the entire length of the small dot breaker 9 is provided. Becomes constant, and more stable chip processing becomes possible regardless of the cutting depth. Also, chips K that can survive the small dot breaker 9 collide with the island-shaped breaker 10 and are bent.
Cut into appropriate lengths and discharged.

In the chip 1 thus configured,
The ratio R2 / of the radius of curvature R1 of the substantially spherical surface of the spherical dot breaker 8 and the radius of curvature R2 of the substantially cylindrical peripheral surface of the small dot breaker 9
If R1 is smaller than 0.2, the small dot breaker 9 is too small, and the chip K easily passes over the small dot breaker 9 during low cutting and low feed, and the small dot breaker 9 separates the chip K. The effect is weak. Conversely, R2
When / R1 is larger than 0.8, the small dot breaker 9 is too large, and the chip K is hard to get over the small dot breaker 9 more than necessary, and chip clogging is likely to occur at high cutting and high feeding. . For this reason, the ratio of the radius of curvature R1 of the substantially spherical surface of the spherical dot breaker 8 to the radius of curvature R2 of the substantially cylindrical peripheral surface of the small dot breaker 9 is 0.2 ≦ R2.
/R1≦0.8 is preferable. Also,
The maximum height D1 (m) from the upper surface 5 of the spherical dot breaker 8
m) and the maximum height D2 from the upper surface 5 of the small dot breaker 9
If the difference H from (mm) is smaller than 0.1 mm, the chips K that have passed over the small dot breakers 9 can easily pass over the spherical dot breakers 8, so that the spherical dot breakers 8
The effect of is almost lost. H is 0.6m
If it is larger than m, the direction in which the chips K that have passed over the small dot breakers 9 travel can be changed more rapidly than necessary by the spherical dot breakers 8, so that the spherical dot breakers 8
Is too strong, and chip clogging is likely to occur. Therefore, the difference H between the maximum height D1 of the spherical dot breaker 8 and the maximum height of the small dot breaker 9 is 0.
It is desirable to set the range of 1 mm ≦ H ≦ 0.6 mm.

According to the chip 1 configured as described above,
Even at the time of cutting at a low depth, which was difficult to process the chip with the conventional chip 31, the chip K can be bent by the small dot breaker 9 with a smaller curl diameter, cut and discharged, and the processing of the chip K can be further improved. Can be performed well. Similarly, even in the case where the end face portion having a high cut and a low feed is pulled up, the chip K can be bent by the small dot breaker 9 and satisfactorily divided and discharged. Further, when cutting with high cutting depth and high feed rate is performed, the chip K is bent by the spherical dot breaker 8, and the chip is satisfactorily divided and discharged. The small dot breaker 9 has a substantially cylindrical peripheral surface shape and the chip K
Are in line contact with each other, so that the progress of partial wear of the small dot breaker 9 is suppressed, and stable chip processing becomes possible. Further, since the small dot breaker 9 has a cylindrical peripheral surface shape extending in a direction substantially parallel to the bisector of the nose part 3, stable chip processing can be performed regardless of the cutting depth.

As described above, the chip K of the small dot breaker 9 or the spherical dot breaker 8 is selected according to the cutting conditions.
The chip K is bent in a direction suitable for the above-mentioned processing, and the processing of the chip K can be favorably performed under a wide range of cutting conditions from low-cut cutting to high-cut cutting and pull-up cutting.

In the above embodiment, the chip 1 has a substantially hexagonal flat plate shape. However, the present invention is not limited to this. For example, the chip 1 may have another polygonal shape. Further, the chip 1 may be a positive chip.

[0018]

EXAMPLE Next, the chip 1 shown in the above embodiment,
A cutting test was performed using a conventional chip without the small dot breaker 9 to compare the cutting performance.
In the first cutting test, the chip processing performance when the end face of the work material W was cut was verified. In this cutting test, a stepped round bar (material: JIS SCr420H) having a shape as shown in FIG. 5 was used as the work material W, and end face continuous cutting was performed in a direction indicated by an arrow α in FIG. The cutting conditions at this time are as follows: cutting speed V = 180 m / mi
n, cutting depth ap = 1.0 mm, feed f = 0.4 m
m / rev and the cutting method was wet cutting (using a water-soluble cutting oil).

FIG. 6A shows the shape of a chip when the work W is cut by the tip 1 according to this embodiment. FIG. 6B shows the shape of the chip W by the conventional tip. Shows the shape of the chips when cutting was performed. As a result of the cutting test, the chips in the conventional chip without the small dot breaker 9 were not divided well and became longer. On the other hand, in the chip 1 according to the present embodiment, the chips were divided at an appropriate length, and it was found that the chips were satisfactorily processed.

As a second cutting test, a round bar (material: JISS45C) shown in FIG.
Outer diameter cutting (cutting in the direction indicated by arrow β) is performed by variously changing the cutting depth ap and the feed f by using the chip 1 according to the present embodiment and the conventional chip, respectively. Cutting depth a to be cut
The area of p and feed f was determined. The result is shown in the graph of FIG. In the cutting test (second cutting test) at this time, the cutting speed V was set to V = 200 m / min, and the cutting method employed was wet cutting. As can be seen from the graph of FIG. 8, the chip 1 according to the present embodiment has a low cutting and low feed chip cutting performance without impairing the chip cutting performance in high cutting and high feed cutting compared to a conventional chip. It is possible to improve.

As can be understood from the above test results, according to the insert 1 of the present invention, as compared with the conventional insert 31, a low cutting depth and a low cutting depth can be obtained without impairing the chip cutting performance in high cutting and high feed cutting. Chips can be satisfactorily processed even when low-feed cutting and end face cutting are performed, and chips can be satisfactorily processed under a wide range of cutting conditions.

[0022]

According to the chip of the present invention, spherical dots are provided on the upper surface forming the rake surface at positions spaced inward from the nose portion and the cutting edge, and small dots are provided on the cutting edge side of the spherical dot. Since the chips are provided, the chips can be bent by small dots, separated, and discharged even at the time of cutting at a low depth of cut and low feed where it is difficult to process chips with the conventional chip. In this case, since the chips are bent with a smaller curl diameter as compared with the case where the chips are bent by the spherical dots, the chips are shorter and more easily broken, and the cutting and discharging of the chips can be further improved. Similarly, even in the case where the end face portion having a high cut and a low feed is pulled up, the chip can be bent by the small dots and separated and discharged well. Here, since the small dots have a substantially cylindrical peripheral surface shape and the chips are in line contact, the progress of partial wear of the small dots is suppressed,
Stable chip processing becomes possible. Since the small dots have a substantially cylindrical peripheral surface shape extending in a direction substantially parallel to the bisector of the nose, stable chip processing can be performed regardless of the cutting depth. Furthermore, since the small dots are provided on the cutting edge side of the spherical dots, the root portions of the spherical dots on the cutting edge side are protected, and wear is less likely to occur.

In the case of cutting at a high depth of cut, the chips shaved by the cutting blades are bent by colliding with the spherical dots after passing over the small dots. Can be separated and discharged. In addition, since the spherical dots are provided apart from the nose portion and the cutting blade, the chips collide with the spherical dots at a predetermined distance after being scraped from the work material by the cutting blade, so that the chips are less likely to be clogged. Cutting resistance is reduced.
In this way, depending on the cutting conditions, of the spherical dots or small dots, the chips will be bent in a direction suitable for the processing of the chips, and from low-cut cutting to high-cut cutting, and pull-up cutting, Chips can be satisfactorily processed under a wide range of cutting conditions.

[Brief description of the drawings]

FIG. 1 is a plan view showing a shape of a chip according to an embodiment of the present invention.

2A is a sectional view taken along the line AA of FIG. 1, and FIG. 2B is a sectional view taken along the line BB of FIG.

FIG. 3 is a diagram showing how chips are processed by the throw away tip according to the embodiment.

FIG. 4 is a diagram showing how chips are processed by the throw-away tip according to the embodiment.

FIG. 5 is a diagram showing a shape of a work material and a cutting procedure used in a first cutting performance test of the indexable insert according to the embodiment.

FIG. 6 (a) is a view showing the shape of a chip generated when cutting a work material by the indexable insert according to the present embodiment, and FIG. 6 (b) is a diagram showing cutting of the work material by a conventional tip. It is a figure which shows the shape of the chip at the time of performing.

FIG. 7 is a view showing a shape of a work material and a cutting procedure used in a second cutting performance test of the indexable insert according to the embodiment.

FIG. 8 is a graph showing regions of a cutting depth ap and a feed f at which chips are satisfactorily divided, for each of the chip 1 according to the present embodiment and a conventional chip.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Chip 2 Chip main body 2a Corner 3 Nose part 4 Side surface 5 Top surface 6 Cutting edge 8 Spherical dot breaker 9 Small dot breaker

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Mitsunobu Nakada 1511 Furamagi, Ishishita-cho, Iki-gun, Ibaraki Prefecture Inside the Tsukuba Works, Mitsubishi Materials Corporation (72) Inventor Osamu Ichinoseki 1511 Furimagi, Ishishita-cho, Yuki-gun, Ibaraki Prefecture Mitsubishi Materials Corporation Tsukuba Works F-term (reference) 3C046 JJ04

Claims (3)

[Claims] A nose portion is formed at a corner of a chip body having a polygonal flat plate shape, and each of a pair of adjacent side surfaces of the chip body sandwiching the nose portion and the chip body connected to the nose portion. A cutting edge is formed on at least one of the two intersecting ridge lines formed with the upper surface of the upper surface, and the upper surface forming a rake surface, on a substantially bisector of the nose portion,
In a throw-away chip provided with spherical dots protruding from the upper surface in a substantially spherical shape, the spherical dots are provided at positions spaced inward from the nose and the cutting edge, and the spherical surface is provided on the upper surface. A throw-away tip, wherein a small dot extending in a direction substantially parallel to the bisector and protruding from the upper surface into a substantially cylindrical peripheral surface shape is provided on the cutting edge side of the dot. 2. A radius of curvature R1 of a substantially spherical surface of the spherical dot.
And the radius of curvature R2 of the substantially cylindrical peripheral surface of the small dot is:
2. The throw-away tip according to claim 1, wherein 0.2 ≦ R2 / R1 ≦ 0.8. 3. The maximum height of the small dots from the upper surface is set lower than the maximum height of the spherical dots from the upper surface, and the difference H between these small dots is 0. 1
The throw-away tip according to claim 1, wherein mm ≦ H ≦ 0.6 mm.