JP2000117513A - Throw-away tip and throw-away type ball end mill - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the occurrence of chattering vibration when heavy cutting having high cutting resistance is effected by using a throw-away tips having a cutting edge in which nicks are formed, to perform high-efficient cutting with high cutting precision, to properly part cutting tips and properly discharge the chips, to prevent lowering of the strength of a throw-away tips due to the nicks, and to perform stable cutting throughout a long period. SOLUTION: In a throw-away tip 10 having a cutting edge 13 in which nicks 14 are formed, the nick is formed approximately in a 1/4 spherical state, and in a throw-away type ball end mill, the throw-away tip 10 is mounted on the rounded tip part of an end mill body.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a throw-away tip for attaching to various cutting tools for cutting and a throw-away type ball end mill having such a throw-away tip attached to a rounded end portion of an end mill body. In particular, when performing heavy cutting in which a large cutting force acts, using a throwaway tip with a nick on the cutting edge to sufficiently reduce the cutting resistance and prevent breakage of the throwaway tip during cutting. The feature is that it is prevented.

[0002]

2. Description of the Related Art Conventionally, indexable inserts have been mounted on various types of cutting tools to perform various types of cutting.

[0003] Here, when performing the cutting by attaching the throw-away tip to the cutting tool as described above, when performing heavy cutting in which a large cutting resistance is applied, chatter vibration occurs in the cutting tool, and the cutting accuracy and There are problems that the cutting efficiency is reduced, the width of the cut chips is widened, and the chips are not discharged well.

[0004] For this reason, when heavy cutting is performed using a cutting tool to which a throw-away tip is attached as described above,
A generally V-shaped or U-shaped nick is provided at the cutting edge portion of the indexable insert, and the material to be cut is not cut at the nick portion, thereby reducing the cutting resistance during heavy cutting. At the same time, the chips to be cut are cut at the nicks to reduce the width of the chips.

Here, in the case of a throw-away type ball end mill in which a throw-away tip is attached to the rounded tip of the end mill body, as shown in FIGS. 1 and 2, the throw-away tip has a substantially elliptical planar shape as shown in FIGS. Attachment holes 1a, 2 for mounting the indexable inserts 1, 2 to the end mill body (not shown) at the center of the plane portion of each indexable insert 1, 2, respectively.
a was provided.

In providing the nicks 1c and 2c having a V-shape or U-shape at the cutting edges 1b and 2b of the above-mentioned indexable inserts 1 and 2 as shown in FIGS. Throwaway tip 1 shown in (B)
When the nick 1c having a small width d is provided in the portion of the cutting edge 1b as described above, the cutting resistance in heavy cutting cannot be sufficiently reduced, and chatter vibration still occurs during cutting, There has been a problem that the cut swarf cannot be cut well by the nick 1c, or even if the swarf is cut, the width of the swarf becomes large and the swarf cannot be discharged well.

On the other hand, when a nick 2c having a large width d is provided at the cutting edge 2b as in the indexable insert 2 shown in FIGS. 2A to 2C, the cutting resistance during heavy cutting decreases. At the same time, the cut chips were also appropriately divided, the width of the chips was narrowed, and the dischargeability of the chips was improved.

However, when the width d of the V-shaped or U-shaped nick 2c is increased, the nick 2c is cut into the vicinity of the mounting hole 2a provided in the center of the indexable tip 2. In rare cases, when the strength of the throw-away tip 2 is reduced and heavy cutting is performed with a large cutting force, the throw-away tip 2 is broken at the cut nick 2c. .

When the nicks 1c and 2c having a V-shape or U-shape are formed on the cutting blades 1b and 2b as described above, as shown in FIGS. 1A and 2A, Nick 1
The edges of the nicks 1c and 2c are easily chipped during cutting, and the edges of the nicks 1c and 2c are sharpened.
As shown in FIG. 2 (C), the rake angle γ at the bottom of the nick 2c increases, and when the bottom of the nick 2c hits the workpiece, the resistance of cutting the workpiece increases. there were.

In particular, in the case of a throw-away type ball end mill in which the above-mentioned throw-away tips 1 and 2 are attached to the rounded tip of the end mill body, the throw-away tips 1 and 2 are required to perform various cutting processes. , 2 are subjected to resistance in various directions, and there is a problem that the throw-away chips 1, 2 are more likely to be chipped.

[0011]

SUMMARY OF THE INVENTION An object of the present invention is to solve the various problems described above when a nick is provided on a cutting edge of a throw-away insert in order to perform heavy cutting with a large cutting resistance. It is assumed that.

That is, in the present invention, when performing heavy cutting with a large cutting resistance using the throw-away insert having a nick on the cutting edge as described above, the cutting resistance is reduced, and chatter vibration and the like are reduced. Generation is suppressed, and cutting with good cutting accuracy can be performed efficiently,
The cut chips are also properly divided, the width of the chips is reduced, the chips are discharged properly, and the strength of the indexable insert is greatly reduced by the nick provided in the indexable insert. It is another object of the present invention to perform stable cutting over a long period of time.

[0013]

According to a first aspect of the present invention, there is provided a throw-away insert having a nick provided on a cutting edge thereof. It was formed into a quarter spherical shape.

Further, when a nick having a substantially 1/4 spherical shape is formed on the cutting edge as in the throw-away tip according to the first aspect of the present invention, even when the width of the nick is increased, the V-shape or the nick is formed. Compared to the U-shaped nick, the nick is not cut deeper toward the center of the throw-away tip, and the decrease in strength of the throw-away tip is suppressed, and the edge of the nick is also gentle. Become.

For this reason, in the indexable insert according to the first aspect, the strength of the indexable insert is reduced even when the width of the nick provided on the cutting edge is widened in order to perform heavy cutting with a large cutting resistance. The cutting force is sufficiently reduced by the wide nick, the occurrence of chattering vibration is suppressed, and accurate cutting can be performed efficiently, and the cut chips are also appropriately divided. The width of the chips becomes narrower, the cut chips are discharged stably, and there is no breakage of the throw-away insert or chipping of the nick edge. It can be performed stably.

In particular, in the case where a mounting hole is provided at the center of the flat portion of the throw-away insert in order to attach the throw-away insert to the cutting tool, the nick provided on the cutting edge as described above. Even if the width of the nick is widened, the nick is not cut into the vicinity of the mounting hole, and in this way, sufficient strength is maintained and stable even in a throwaway tip with a mounting hole in the center of the flat part Cutting can be performed.

According to a third aspect of the present invention, there is provided a throw-away type ball end mill in which a throw-away tip is attached to a rounded tip of an end mill body. Approximately 1 /
Thus, a nick having a spherical shape was formed.

When a throw-away tip in which a nick having a substantially 1/4 spherical shape is formed on the cutting edge as in the throw-away type ball end mill according to claim 3, the above-described claim 1 can be used. Similarly to the case of the throw-away insert, even when the width of the nick provided on the cutting edge is widened, the decrease in the strength of the throw-away insert is suppressed, and the cutting force is sufficiently reduced by the wide nick, and the chatter is performed. The occurrence of vibration and the like is suppressed, so that accurate cutting can be efficiently performed, and the cut chips are also appropriately divided, the width of the chips is reduced, and the cut chips are stably discharged. Become like

Furthermore, in the throw-away type ball end mill according to the third aspect, even when cutting is performed in various directions, chipping in the throw-away tip is suppressed, and stable cutting can be performed for a long period of time. Become like

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A throw-away tip and a throw-away type ball end mill according to an embodiment of the present invention will be specifically described below with reference to the accompanying drawings.

Here, the throw-away tip 10 in this embodiment also has a structure as shown in FIGS.
The throw-away chips 1, 1 shown in FIGS.
As in the case of 2, the planar shape is formed into a substantially elliptical shape,
A mounting hole 12 for mounting to the end mill main body is provided at the center of the flat portion 11, and a cutting edge 13 is formed at each of the elliptical arc-shaped edges.

In the indexable insert 10 of this embodiment, two approximately 1/4 spherical nicks 14 are provided at appropriate positions on the two cutting edges 13 at a required interval. Provided.

Here, when each cutting edge 13 is provided with a nick 14 having a substantially 1/4 spherical shape like the indexable insert 10 in this embodiment, the width d of the nick 14 is increased. Even in the case, FIG.
As shown in FIG. 2, the nick 14 is not cut deeply into the vicinity of the mounting hole 12 provided at the center of the throw-away tip 10, and the strength of the throw-away tip 10 is greatly reduced by the nick 14. Absent.

When the nicks 14 having a substantially quarter spherical shape are provided, as shown in FIG.
The edge 14a of the nick 14 does not become angular, so that the edge 14a of the nick 14 is prevented from being chipped during cutting, and at the same time, as shown in FIG. The angle γ is reduced, and when the bottom of the nick 14 hits the workpiece, the resistance for cutting the workpiece is also reduced.

In the throw-away type ball end mill according to the embodiment of the present invention, in addition to the above-mentioned throw-away tip 10, as shown in FIG. The end mill body 3 is formed in a substantially elliptical shape,
1, and a cutting edge 23 is formed on each of the elliptical arc-shaped edges, and approximately 1/1 is located at an appropriate position in the two cutting edges 23. A throw-away tip 20 provided with two spherical nicks 24 at required intervals.
Was used.

In the throw-away type ball end mill of this embodiment, screws are passed through the mounting holes 12 and 22 provided in the above-described throw-away chips 10 and 20, and each of the tips is rounded to the rounded end portion of the end mill body 31. The indexable inserts 10 and 20 are attached. In addition, each indexable tip 1
When attaching 0, 20 to the rounded tip of the end mill body 31, each throw-away tip 10,
In 20, the nicks 14, 24 provided on the respective cutting blades 13, 23 located on the outer peripheral side for cutting are prevented from overlapping in the direction orthogonal to the axial direction of the end mill body 31.

Here, in the throw-away type ball end mill according to this embodiment, the width d of the nicks 14, 24 provided on each of the above-mentioned throw-away chips 10, 20 is described.
Nicks 14, 24
Are approximately 1/4 spherical, so the nicks 14,2
4 is not cut deeply near the mounting holes 12, 22 at the center of each of the throw-away tips 10, 20, and each of the throw-away tips 10, 20 has sufficient strength.

When the throw-away type ball end mill in this embodiment is rotated to cut an object to be cut, even in the case of performing heavy cutting in which a large cutting resistance acts, as described above, each of the throw-away tips 1 is used.
Each of the nicks 14 and 24 having a large width d provided on the 0 and 20 cutting edges 13 and 23 sufficiently reduces the cutting resistance, suppresses chatter vibration and the like, and enables efficient and accurate cutting. Also, the cut chips are appropriately divided by the nicks 14 and 24, and the width of the chips is reduced, so that the chip discharge performance is improved.

In the throw-away type ball end mill according to this embodiment, each of the throw-away tips 10, 20 has sufficient strength as described above, and the nicks 14, 24 provided on the respective cutting edges 13, 23. Since the edges of the inserts do not become angular, even when cutting is performed in various directions with this throw-away type ball end mill, each of the throw-away tips 10 and 20 can be used.
, And the edges of the nicks 14 and 24 are not chipped and stable cutting can be performed.

Next, as shown in the above embodiment, the cutting blades 13 and 23 have nicks 14 and 2 having a substantially 1/4 spherical shape.
Example 1 using a throw-away tip 10 or 20 provided with a throw-away tip 4 and a U-shaped or V-shaped cutting edge 1b or 2b as shown in FIGS. In the case of cutting with the throw-away ball end mills of Comparative Examples 1 and 2 using the throw-away tips 1 and 2 provided with the nicks 1c and 2c, , While cutting resistance is reduced,
It is clarified that breakage in the indexable inserts 10 and 20 is suppressed.

Here, in the throw-away type ball end mills of Example 1 and Comparative Examples 1 and 2, as shown in FIG. 4, two throw-away tips were attached to the rounded tip of the end mill body. In No. 1, a throw-away tip provided with two nicks having a width of approximately 1/4 of a width of 5 mm and a sphere having a width of about 1/4 in each cutting blade portion at a required interval was used, while in Comparative Example 1, In the comparative example 3, a throw-away tip provided with two V-shaped or U-shaped nicks each having a width of 3.3 mm at a predetermined interval at each cutting edge was provided. As the throw-away tip, one provided with two V-shaped or U-shaped nicks having a width of 5.0 mm at a predetermined interval at each cutting edge portion was used.

Then, each of the throw-away chips was attached to the rounded tip of the ball end mill body, and each of the throw-away ball end mills of Example 1 and Comparative Examples 1 and 2 was used.
m, cut 30 mm, feed rate 0.5 mm / re
The vehicle was made to run sideways under the condition of v to cut the material to be cut composed of SKD61.

As a result, in the throw-away type ball end mill of Example 1 described above, a comparative example using a throw-away tip provided with two V-shaped or U-shaped nicks having a width of 3.3 mm. As compared with the indexable ball end mill of No. 1, the power consumption was reduced by about 11%, and the cutting resistance during cutting was reduced.

Further, in the throw-away type ball end mill of Comparative Example 2 using a throw-away tip provided with two V-shaped or U-shaped nicks having a width of 5.0 mm, the cutting resistance was not higher than that of the embodiment. Comparative Example 2 was reduced as in the case of the indexable ball end mill of Example 1.
In the throw-away type ball end mill described above, the nick portion of the throw-away tip used was chipped.

In the above-described embodiment, the case where the throw-away insert is used for the throw-away ball end mill has been described. However, the planar shape of the throw-away insert may be changed to be used for other cutting tools. It is possible.

[0036]

As described above in detail, in the indexable insert according to the present invention, when the nick is provided on the cutting edge, the nick having a substantially 1/4 spherical shape is provided. When the width of the nick is increased as compared with the case where a nick having a U-shape is provided, the nick is not cut deeply toward the center of the throw-away tip, and the strength of the throw-away tip is increased. And the edge of the nick became gentler.

As a result, when performing heavy cutting in which a large cutting force is applied by using the indexable insert according to the first aspect, if the width of the nick provided on the cutting edge is increased, the cutting resistance is sufficiently reduced by the nick. Therefore, the occurrence of chatter vibration and the like is suppressed, and high-precision cutting can be performed efficiently.Moreover, the cut chips are appropriately divided by this nick to reduce the width, and the discharge of the chips is stabilized. As well as being performed, it was possible to stably perform good cutting without breakage of the throw-away tip and chipping of the nick edge during cutting.

In the throw-away type ball end mill according to the present invention, when the throw-away tip is attached to the rounded end portion of the end mill body, a substantially 1/4 spherical nick is formed on the cutting edge. Since the indexable insert is used, as in the case of the indexable insert described above, when performing heavy cutting in which a large cutting resistance is added, if the width of the nick provided on the cutting edge is increased, the cutting resistance is reduced by the nick. Sufficiently reduced, the occurrence of chatter vibration etc. is suppressed, accurate cutting can be performed efficiently, and the cut chips are also appropriately divided by this nick and the width is narrowed, and the discharge of chips Also came to be performed stably.

Also, even when cutting is performed in various directions by the throw-away type ball end mill of the present invention, the throw-away tip is not damaged and the edge of the nick is not chipped. Cutting can be performed stably.

[Brief description of the drawings]

FIG. 1 is a plan view and a partial explanatory view of a nick portion of a conventional throw-away tip used in a throw-away type ball end mill, in which a width of a nick provided on a cutting blade is reduced.

FIG. 2 is a plan view, a partial explanatory view of a nick portion, and a cross-sectional explanatory view of a nick portion of a conventional throw-away tip used in a throw-away type ball end mill, in which a nick provided on a cutting blade has a wider nick width. is there.

FIG. 3 is a plan view, a partial explanatory view of a nick portion, and a cross-sectional explanatory view of a nick portion according to an embodiment of the present invention.

FIG. 4 is a front view of a throw-away type ball end mill according to an embodiment of the present invention.

[Explanation of symbols]

 10, 20 Indexable insert 11 Flat part 12, 22 Mounting hole 13, 23 Cutting edge 14, 24 Nick 31 End mill body

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Toshiya Nakada 2-1-1-18 Kamihigashi, Hirano-ku, Osaka Dai-Jet Industrial Co., Ltd. F-term (reference) 3C022 KK02 KK06 KK12 KK23 KK25 LL01 LL02 QQ03 QQ07 3C046 BB02 EE01

Claims (3)

[Claims] 1. A throw-away tip having a nick provided on a cutting edge, wherein the nick is formed in a substantially 1/4 spherical shape. 2. The throw-away tip according to claim 1, wherein a mounting hole is provided at the center of a plane portion of the throw-away tip. 3. In a throw-away type ball end mill in which a throw-away tip is attached to a rounded tip portion of an end mill main body, a nick having a substantially 1/4 spherical shape is formed on a cutting edge of the throw-away tip. A throw-away type ball end mill characterized by being formed.