JPH02167608A - Throw-away tip - Google Patents

Abstract

PURPOSE:To finely cut off chips and improve accuracy in working in a throw-away cutting tip by forming a cutting edge of a cutting edge part and finishing cutting edge part to provide notches only on the cutting edge part. CONSTITUTION:When a throw-away tip 1 is fed leftward, the cutting edge part 8A of a cutting edge 2 shares most part of cutting(a) to form a great amount of chips which are finely divided by notches 3A provided on the cutting edge part 8A which leaves relatively large irregularities by the notches 3A. A finishing cutting edge part 7A having slight notches cuts off the irregularities formed by the notches 3A to generate a satisfactory finished surface. Namely the roughness H in the direction of feeding the finishing surface 5 is a theoretical finished one only generated according to the formula, H=f<2>/8R (f is feed of mm/revolution and R a nose radius (mm) of throw-away tip), leaving no trace of the irregularities due to the presence of notches 3A. The requirement for the feed f is determined to be W>f>P.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to an indexable insert, and more particularly to an indexable insert for cutting in which a notch is carved in the cutting edge of the insert.

(Prior Art) In cutting processing, especially cutting processing using a lathe, long continuous chips not only get entangled with the cutting tool and damage the finished surface of the workpiece, but also make it extremely difficult to dispose of the chips. Therefore, by forming a chip breaker on the cutting tool to cut the chips into a predetermined length, or by carving a notch in the cutting edge of the cutting tool to divide the generated chips into thin pieces, it is possible to improve the chip disposal efficiency. efforts are being made to improve

FIGS. 17(a) and (b) show a conventional indexable insert with these notches. The cutting edge 2 of the indexable insert 1 is provided with notches 3 at a predetermined pitch over its entire length. There is. Due to the presence of the notch 3, the indexable tip 1 efficiently divides chips into fine pieces and has a shape that is easy to process.

(The problem that the invention attempts to solve) However, this indexable tip with a notch
As shown in the figure, the finished surface 5 of the workpiece 4 has irregularities corresponding to the above-mentioned notches. For this reason, conventional notched indexable inserts can only be used for rough machining that does not require machining/r-method accuracy or finished surface roughness, and when high machining dimensional accuracy or finished surface roughness is required, further processing is required. There was a problem in that finishing processing had to be performed.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an indexable tip which can cut chips into fine pieces with notches and which can improve the finished surface roughness and dimensional accuracy of a workpiece.

[Structure of the invention]

(Means for Solving the Problems) In order to achieve this object, the present invention provides a cutting edge portion that performs most of the cutting into the workpiece, and a finishing portion of the portion cut by the cutting edge portion. A cutting edge is constituted by a finishing cutting edge portion for cutting, and a notch is carved only in the above-mentioned cutting cutting edge portion.

It is desirable that a plurality of the notches are formed at substantially equal pitches to the cutting edge portion, and the length of the finishing cutting edge portion is set to be larger than the pitch.

Further, when the indexable insert has a polygonal shape, the finishing cutting edge portion is formed at the center of the side of the polygon, and the cutting edge portions are formed on both sides of the center portion. Preferably, a plurality of the notches are formed in the cutting edge portion.

On the other hand, when the indexable insert has a circular shape, the cutting edge portion for cutting and the cutting edge portion for finishing are formed alternately, and a plurality of the notches are carved in the cutting edge portion for cutting. It is preferable that

(Function) Since a notch is carved in the cutting edge portion that performs most of the cutting into the workpiece, the generated chips are cut into thin pieces. The finishing cutting edge cuts the unevenness caused by the notch of the cutting cutting edge and creates a smooth finished surface. Furthermore, compared to the case where notches are not formed, cutting resistance is reduced due to the reduced strength of the shredded chips, and chatter vibration is suppressed, resulting in better finished surface roughness and dimensional accuracy.

(Example) Examples of the indexable tip according to the present invention will be described below with reference to FIGS. 1 to 16, in which the same parts as in FIGS. 17 and 18 are denoted by the same reference numerals. .

In FIGS. 1(a) and 1(b), the indexable tip 1 has a substantially triangular planar shape consisting of three convexly curved sides, and a cutting edge 2 is formed on each side. Each 9J blade 2 is comprised of a finishing cutting edge 7 formed in the center and cutting cutting edges 8 formed on both leg sides thereof. A plurality of notches 3 are formed in each of these cutting edge portions 8 at approximately equal pitches p. These notches 3 have a U-shaped or V-shaped cross section, and extend from the upper surface to the lower surface of the indexable tip 1, that is, over the entire thickness t, as shown in FIG. 1(b). The pitch p is set to be sufficiently larger than the width g of the notch 3. Further, the length W of the finishing cutting edge portion 7 is set to be larger than the pitch p.

Next, the operation of this implementation IF 11 will be explained.

Fig. 2 shows the state in which the indexable insert 1 is cutting the rotary workpiece 4 with the depth of cut a.When the indexable insert 1 is fed to the left in Fig. 2, the cutting edge 2 The cutting edge part 8A on the left side takes up most of the above-mentioned cutting depth a and forms a large amount of cuts 1r (1r). ). The cutting edge portion 8A leaves relatively larger unevenness than the notch 3A+. The finishing cutting blade 7i cuts the unevenness caused by the notch 3A with a single force of cut to create a good finished surface. That is, the roughness H of the created finished surface 5 in the feeding direction is H−f/8R(fi!feeding f
(mm/rotation), and R is the nose radius (aIll) of the indexable tip. ), the theoretical finished surface roughness determined by L) is only increased, and no trace of unevenness is left due to the presence of the notch 3A. This feed f is the condition w>f>p
This is determined so as to satisfy the following conditions. Note that when the feeding direction of the right-hand infeed cutting edge 8Bi is opposite to that described above, that is, when it is in the right direction, one is used.

In addition, as described above, the strength of the chips is reduced due to the cutting being shredded, so the cutting resistance is reduced and the generation of IJ vibration is suppressed a little more than in the case where the notch 3 is not provided in the cutting edge part 8. Finished surface roughness and machining force (improved).

Furthermore, the notch 3 also acts as a path for cutting curves, etc., effectively guiding the cutting curves, etc. to the cutting location and its vicinity, cooling the cutting heat, and reducing frictional resistance due to the lubrication effect, improving machinability. Tool life can be extended.

FIGS. 3(a) and 3(b) show a modification of the above embodiment, in which the notches 3 do not extend from the upper surface to the lower surface of the indexable tip 1, but from the upper and lower surfaces, respectively. It extends by a certain amount u (u<t), and the shape of the notch 3 is also determined to be an isosceles triangle as shown in FIG. 3(b).

FIGS. 4 and 5 show examples in which the outer periphery of a triangular indexable tip is made straight.

FIGS. 6 and 7 show an example of a trapezoidal positive type indexable tip that can be used on one side.

FIGS. 8 and 9 show examples in which each side of the approximately triangular indexable tip is formed into a concave curved surface.

As shown in these examples, the width and depth d of the notches 3 may be different from one another, and the length U of the notches 3 may also be redundant.

Figures m10 and 11 show examples in which the indexable tip is approximately rectangular and circular, respectively, and the indexable tip shown in Figure 10 is provided with a chip breaker 9. The circular indexable insert shown in FIG. 11 has finishing cutting edges 7 and cutting edges 8 formed alternately. Note that FIG. 12 shows the state of cutting with the solid indexable tip.

As is clear from the above examples, the indexable tip according to the present invention can have an arbitrary external shape such as a triangle, a quadrangle, other polygons, or a circle.

13 to 15 show a cutting edge 8 with a notch 3 formed in the center of each cutting edge 2 of a polygonal indexable insert, and a finishing cutting edge 7 formed on the inner periphery thereof. This is an example. In the indexable insert 1 having such a configuration, as shown in FIG. 16, the cutting cutting edge 8 makes most of the cutting depth a, and finishing is done with the finishing cutting edge 7A on one side.

The finishing cutting edge 7B on the other side is used when reversing the feeding direction of the indexable insert 1.

In this example, there are two finishing cutting edges 7A on one side.

7B, it is more economical than the above example.

In addition, in the example shown in FIG. 15, the notches 3 are carved from the outer periphery of the indexable tip 1 toward the center on the upper and lower surfaces, respectively, so the length U of the notches 3 at the outer periphery is relatively It's shorter.

All of the above-mentioned indexable tips were installed by using the hole 10 to clamp them to the holder, but in this installation, the upper part of the indexable tip was pressed with a metal fitting instead of the hole and fixed to the holder. You can.

Furthermore, the present invention is not only applicable to indexable inserts used in turning bits as in the above-mentioned example, but also to milling tools for turning.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, there is provided a cutting edge portion that makes most of the cut into the workpiece, and a finishing cutting edge that performs finishing cutting on the portion cut by the cutting edge portion. A cutting edge is formed from the above-mentioned cutting edge part, and a notch is carved only in the cutting edge part, so the chips are divided into fine pieces by the notch, improving chip disposal. Since a finished surface is created by the cutting edge, the finished surface roughness and machining accuracy can be sufficiently improved.Historically, cutting force is reduced by shredding the chips mentioned above, and chatter vibration is also reduced, so the finished surface roughness can be improved. It gets even better.

Also, cutting process 1. When a cutting agent is used for +i, this cutting fluid flows into the notch, so this cutting agent is not ゛,! Effectively acts on K, extending tool life and improving cutting performance.

[Brief explanation of the drawing]

FIGS. 1(a) and (b) are a plan view and a front view showing an embodiment of the indexable tip according to the present invention, and FIG. 2 is a partial sectional view showing a cutting state by the indexable tip of the above embodiment. , FIGS. 3(a), (b) to FIG. 11(a)
, (b) are a plan view and a front view respectively showing a modification of the above embodiment, FIG. 12 is a partial cross-sectional view showing a cutting state with the indexable tip of FIG. 11, and FIG. 13(a), (b
) to 15(a) and 15(b) are a plan view and a front view showing another modification of the above embodiment, respectively, and FIG. 16 is a plan view showing a cutting state with the indexable tip of FIG. 14. ,
17(a) and 17(b) are a plan view and a front view showing a conventional notched indexable tip, and FIG. 18 is a 17th
FIG. 3 is a partial cross-sectional view showing a Q cutting state using the conventional notched indexable insert shown in the figure. 1... Throwaway tip, 2... Cutting blade, 3...
・Notch, 4... Workpiece, 7... Finishing cutting edge, 8.
... Cutting edge for cutting. Applicant's agent Sato - Yume 3 figure 16 figure 6 figure 7 figure trap 4 figure 5 figure 8 figure 9 figure 10 figure 11 figure Pl+4 figure 15 figure 12 section'P) 13th figure 17th figure old figure

Claims (1)

[Scope of Claims] 1. A cutting edge is separated from a cutting edge that makes most of the cut into the workpiece and a finishing cutting edge that performs finishing cutting on the part cut by the cutting edge. 1. A throw-away insert characterized in that a notch is carved only in the cutting edge portion. 2. A plurality of the notches are formed on the cutting edge portion at substantially equal pitches, and the length of the finishing cutting edge portion is set to be larger than the pitch. Throwaway tip. 3. The indexable insert has a polygonal shape, and the finishing cutting edge is formed at the center of the side of the polygon,
2. The indexable insert according to claim 1, wherein the cutting edge portions are formed on both sides of the central portion, and a plurality of notches are formed in the cutting edge portion. 4. The indexable tip has a circular shape, and the cutting edge portions and the finishing cutting edge portions are alternately formed,
2. The indexable insert according to claim 1, wherein a plurality of said notches are formed in said cutting edge portion.