WO2015137133A1

WO2015137133A1 - Cutting insert and replaceable blade cutting tool using same

Info

Publication number: WO2015137133A1
Application number: PCT/JP2015/055576
Authority: WO
Inventors: 奉章福山; 伸也藤沢
Original assignee: 住友電工ハードメタル株式会社
Priority date: 2014-03-12
Filing date: 2015-02-26
Publication date: 2015-09-17
Also published as: JP2017080817A

Abstract

Provided is a cutting insert, wherein a rake face and a breaker protrusion formed on the rake face of a corner portion are included, a breaker wall of the breaker protrusion is curved in a recessed shape, and the rake face of the corner portion and the lower end of the breaker wall of the breaker protrusion run together to form an angle difference.

Description

Cutting insert and cutting edge exchangeable cutting tool using the same

This invention relates to a cutting insert with improved chip disposal performance and a cutting edge exchangeable cutting tool using the cutting insert.

Cutting tools are required to have the ability to satisfactorily treat chips generated during cutting. As a method to meet the demand, a breaker groove or a breaker protrusion is provided on the rake face of the cutting insert, and the breaker groove and the breaker protrusion are used in combination.

場合 Chips that are difficult to break are generated especially when the work material is low carbon steel such as mild steel or general steel with strong stickiness. If the depth of cut is shallow, the generated chips are more difficult to break.

The following Patent Document 1 proposes a cutting insert that enables chip disposal under a wide range of feed conditions in a finishing area with a shallow depth of cut for a highly sticky work material.

The cutting insert of Patent Document 1 uses a breaker groove and a breaker projection in combination, and the side cutting edge connected to both ends of the corner cutting edge is given an inclination that descends at an angle of 3 to 8 ° as it moves away from the corner cutting edge. Yes. Further, the breaker protrusion has a height of 0.25 mm to 0.35 mm with respect to the tip of the corner portion.

In addition, the breaker protrusion provided in the cutting insert of Patent Document 1 rises linearly with an inclined breaker wall on which chips collide.

The breaker protrusion breaker wall generally has a convex arcuate bulge or rises linearly, and the breaker protrusion of Patent Document 1 is set to be higher than a general one. As for the shape, it can be said to be a general protrusion.

JP 2002-301606 A

The breaker protrusion as shown in Patent Document 1 has a small chip contact area with respect to the breaker wall. For this reason, it is difficult to stabilize the outflow state and the processing state of the chip.

In addition, since the contact area of the chip with the breaker wall is small, the chip contact area of the rake face and the breaker wall is selectively worn and damaged due to the concentration of load, and the flow of chips changes as the wear and damage progress. Chip processing performance becomes unstable.

Therefore, the maintenance time of stable chip disposal performance is shortened. Furthermore, since the contact area of the chips is small, the distortion applied to the chips tends to be insufficient, and it is difficult to say that the chip breaking property is sufficient. In addition, since the flow of chips becomes unstable, the number of cases where chips are discharged without being divided increases, and troubles such as entanglement with tools, workpieces, jigs, chucks, etc. are likely to occur.

The entanglement causes temporary stoppage of the equipment, idling, etc., and causes a sudden loss of the cutting edge.

In order to eliminate the above-mentioned problems, the present invention is designed so that, in the cutting of a sticky metal material, stable chip disposal performance is maintained for a long time under a wide range of processing conditions, and excellent processing stability is maintained. The challenge is to do.

In order to solve the above problems, the present invention is a cutting insert, comprising a scooping face and a breaker protrusion formed on the scooping face of a corner portion, and the breaker wall of the breaker protrusion is concavely curved, Further, a cutting insert in which the rake face of the corner portion and the lower end of the breaker wall of the breaker projection are connected with an angle difference.

This cutting insert is detachably attached to the tip of the holder to constitute a cutting edge exchangeable cutting tool. The present invention also provides the cutting edge exchangeable cutting tool.

The cutting insert and the cutting edge-exchangeable cutting tool using the cutting insert improve the chip breaking property.
Moreover, the selective wear of the rake face and the breaker wall is suppressed, and fluctuations in the outflow state and the processing state of the chips are suppressed, and the flow of the chips is stabilized and the processing performance is improved. As a result, the frequency of occurrence of troubles such as entanglement of chips, sudden chipping of the cutting edge, and temporary stoppage of equipment is reduced.

Furthermore, the stable performance maintenance time is longer than that of the conventional product, and the service life is improved.

It is a top view which shows an example of the cutting insert of this invention. It is an enlarged plan view of the corner part of the cutting insert of FIG. FIG. 3 is a cross-sectional view taken along line XX in FIG. 2. FIG. 4 is a diagram showing a cross-sectional shape along line YY in FIG. 3. FIG. 4 is a diagram showing another example of a cross-sectional shape along the YY line in FIG. 3. FIG. 10 is a diagram showing still another example of a cross-sectional shape along the YY line in FIG. 3. It is sectional drawing along the bisector of the corner angle of the corner part of the cutting insert which provided the land along the cutting edge. It is a top view which shows an example of the blade-tip-exchange-type cutting tool of this invention. It is an enlarged plan view of the corner part of the sample I used for the performance evaluation test. It is an enlarged plan view of the corner part of the sample III used for the performance evaluation test. FIG. 3 is a diagram showing the cross-sectional shape along the bisector of the corner angle of the corner portion of the cutting inserts of samples I to III used in the performance evaluation test. It is a figure which shows the chip | tip produced | generated by the sample I in the performance evaluation test. It is a figure which shows the chip | tip produced | generated by the sample II in the performance evaluation test. It is a figure which shows the chip | tip produced | generated by the sample III in the performance evaluation test.

Hereinafter, an embodiment of a cutting insert and a cutting edge-exchangeable cutting tool according to the present invention will be described with reference to FIGS. 1 to 11 of the accompanying drawings.

FIG. 1 shows the present invention applied to a triangular cutting insert. The illustrated cutting insert 1 uses the ridgeline at the intersection of the upper surface 2 and the side surface 3 as the cutting edge 4.

On the upper surface 2 of the cutting insert 1, a rake surface 5 is provided along the cutting edge 4.
As shown in FIG. 3, the rake face 5 of the exemplified cutting insert 1 is inclined in a direction approaching the lower face as the distance from the cutting edge 4 is increased, thereby forming a breaker groove.

The inclination angle of the rake face 5 with respect to the reference plane A (which is parallel to the flat lower surface of the cutting insert) is defined here as θ ₁ .

The rake angle at the position along the bisector of the corner angle (XX line in FIG. 2) of the rake face 5 does not necessarily have to coincide with the rake angle at other positions.

The top surface 2 of the cutting insert 1 is further provided with a flat land portion 6 on the top surface based on a triangle at a position biased toward each corner side, and the position corresponds to the corner of the cutting insert 1 of the land portion 6. A breaker protrusion 7 is continuously provided at the corner. Reference numeral 8 denotes an attachment hole provided in the center of the cutting insert 1 so as to penetrate from the upper surface to the lower surface. The attachment hole 8 is provided as necessary.

The scissor breaker projection 7 protrudes toward the top of the corner of the cutting insert, and is a breaker wall 7a whose front surface in the protruding direction rises from the end of the scoop surface (the end on the side far from the cutting edge 4).

As shown in FIG. 3, the heel breaker wall 7a has a concavely curved cross section along a bisector of the corner angle (the XX line in FIG. 2).

The breaker protrusion 7 has a cross-sectional shape as shown in FIG. 4 in which the breaker wall 7a is rounded, a cross-sectional shape as shown in FIG. 5 in which the center of the breaker wall 7a is recessed, or a shape in which the breaker wall 7a is flat in FIG. Any of the cross-sectional shapes shown may be used.

Moreover, the breaker wall 7a may not be a circular arc surface having a constant curvature. A compound curved surface obtained by combining a plurality of circular arc surfaces having different curvature radii may be used.

Its relative breaker wall 7a of the breaker protrusions 7 as shown in FIG. 3, the rake face 5 brought Ren'nara angularly difference theta _2.

In addition, although the rake face 5 of FIG. 3 is a blade without a land, the rake face 5 is a surface provided with lands 9 for cutting edge reinforcement along the cutting edge 4, as shown in FIG. It may be.
The land 9 may be any one of a flat land having a rake angle of 0 °, a negative land having a negative rake angle, and a positive land having a positive rake angle.

The inclination angle θ _{1 of} the rake face 5 shown in FIG. 3 and FIG. 7, the angle difference θ ₂ of the connection point between the rake face 5 and the breaker wall 7a, the crossing angle θ _{3 of} the breaker wall 7a with the reference plane A, the breaker width ( The distance from the cutting edge 4 to the tip of the top of the breaker projection 7) W ₁ , the width of the rake face 5 {the distance from the cutting edge to the end of the rake face (= starting edge of the breaker wall 7a)} W ₂ , the width of the land 9 Preferable numerical values relating to W ₃ and the height of the breaker protrusion 7 (height of the breaker protrusion 7 from the cutting edge 4) H are listed below.

・ 0 ° ≦ θ ₁ ≦ 25 °
・ 5 ° ≦ θ ₂ ≦ 25 °
・ 20 ° ≦ θ ₃ ≦ 70 °
・ 0.5mm ≦ W ₁ ≦ 5.0mm
・ 0.2 × W ₁ ≦ W ₂ ≦ 0.8 × W ₁
・ 0 ≦ W ₃ ≦ 0.1 × W ₁
-0.25 × W ₁ ≦ H ≦ 0.25 × W ₁

When the inclination angle θ ₁ of the rake face 5 is 0 °, the strain applied to the chips depends only on the breaker wall 7a. Further, when the inclination angle θ ₁ exceeds 25 °, it becomes difficult to ensure the strength of the blade edge. Considering both the chip treatment and the strength of the blade edge, about 15 ° to 25 ° is more preferable.

The angle difference θ ₂ between the rake face 5 and the breaker wall 7a must be 5 ° or more. This angle difference θ ₂ plays an important role in the chip breaking process. When the angle difference theta ₂ is less than 5 °, hardly broken chips too small distortion given to the chip.

Moreover, the stability of the cutting is lost becomes the the angle difference theta ₂ is too excessive outflow resistance of the chip is large.

If the angle of intersection θ ₃ with the reference plane A of the breaker wall 7a is less than 20 °, it is difficult to effectively distort the chips, and if it exceeds 70 °, the outflow of the chips is hindered. The crossing angle θ ₃ is particularly preferably about 20 ° to 45 °.

If the breaker width W ₁ is too small, chips are likely to be clogged. Conversely, if the width is too large, it is difficult to effectively impart distortion to the chips. Therefore, it is preferable to set the width to 0.5 mm to 5.0 mm. .

The width _{W 2} of the rake face 5 is also preferably adjusted to obtain 0.2 times to 0.8 times the breaker width _{W 1} for the same reason.

Further, the height H of the breaker protrusion 7 is good for chip disposal even if the apex position of the breaker protrusion 7 is lower than the cutting edge 4 depending on other specifications such as the inclination angle of the rake face. However, if the height H is too low, the chips flow without coming into contact with the breaker wall, and if the height H is too high, the chips are likely to clog, so that W ₁ is -0.25 times to 0.25 times. Double is appropriate.

FIG. 8 shows an example of a cutting edge-exchangeable cutting tool constructed by detachably attaching the cutting insert 1 of FIG. 1 to the tip of the holder 10. That in the figure is a byte. The cutting insert 1 is fixed to the holder 10 by using a well-known clamp mechanism, for example, a lever lock type clamp mechanism, a pull-in pin, an eccentric shaft, a clamp bolt, a clamp piece, or the like.

性能 A performance evaluation test of the cutting insert of the present invention was conducted. The results are described below. In the test, three types were used: Sample I with the corner portion having the planar view shape of FIG. 9, Sample II having the planar view shape of FIG. 2, and Sample III having the planar view shape of FIG.

B1 in FIG. 11 is a cross-sectional shape along the corner angle of the corner portion of the sample I, B2 is a cross-sectional shape along the corner angle of the corner portion of the sample II, and B3 is a corner angle of the corner portion of the sample III. The cross-sectional shapes along are shown respectively.

In the sample I, the rake angle of the rake face is set to 15 °, which is the same as that of the sample II, the width of the rake face is made larger than that of the sample II, and the breaker wall 7a of the breaker projection 7 is a convex curved surface.

In the sample II, the breaker wall of the breaker projection is a concave curved surface having a radius r = 1.25 mm, and the rake face 5 is connected to the breaker wall with an angle difference.

In Sample III, the rake angle of the rake face and the width of the rake face are the same as those of Sample II, and the breaker wall of the breaker projection is a convex curved surface that is symmetrical to the concave curved surface of Sample II.

Breaker width _{W 1} are all of the samples were also the 0.8 mm. Further, the height H of the breaker protrusion was set to 0.1 mm for each sample. Each sample used was Cermet T1500A manufactured by Sumitomo Hard Metal as a material.

Using the above three types of cutting inserts, cut STKM13A (carbon steel pipe for machine structure) with a diameter of 30 mm ap: 0.2 mm, 0.5 mm, 1.0 mm, 1.5 mm, feed f: 0.05 mm / rev , 0.10 mm / rev, 0.15 mm / rev, 0.20 mm / rev, and 0.25 mm / rev. The cutting speed was V: 200 m / min in all cases.

形状 The shapes of chips generated in this evaluation test are shown in FIGS. 12A to 12C, respectively.

As shown in FIG. 12A, the chips from the sample I have the conditions of a cutting ap: 1.0 mm, a feeding f: 0.20 mm / rev, a cutting ap: 0.5 mm, a feeding f: 0.05 mm / rev to 0. Chips under the condition of 25 mm / rev are treated well, but chips under other processing conditions are not satisfactorily treated.

Further, as shown in FIG. 12C, the chips from the sample III are treated to some extent under the conditions of a cutting ap: 0.5 mm and a feed f: 0.10 mm / rev and 0.15 mm / rev. The chips under the above processing conditions extend long and are easily entangled with the work material.

On the other hand, as shown in FIG. 12B, the chips from Sample II are excellent under a wide range of conditions of notches ap: 0.5 mm and 1.0 mm and feed f: 0.10 mm / rev to 0.25 mm / rev. Has been processed.

In Samples I and III, the rake face is connected to the breaker wall of the breaker projection with an angle difference, but the chip processing performance is inferior to that of Sample II. As a result, the effectiveness of making the breaker wall of the breaker projection into a concave curved surface clearly appears.

As a performance evaluation, cutting under the above processing conditions was repeated until the cutting length reached 4000 m, and the presence or absence of wear on the rake face and the breaker wall was also examined. As a result, wear that can be visually confirmed was observed in Samples I and III, but no wear portion was observed in Sample II.

Although the above description has been given by taking an example of a regular triangular cutting insert, the present invention can also be applied to cutting inserts of other shapes such as a diamond shape.

The material of the bag is not limited to cermet T1500A. For example, a coated cermet T1500Z manufactured by Sumitomo Electric Hardmetal Co., a cemented carbide, a coated cemented carbide or the like may be used.

DESCRIPTION OF SYMBOLS 1 Cutting insert 2 Upper surface 3 Side surface 4 Cutting edge 5 Rake face 6 Land part 7 Breaker protrusion 7a Breaker wall 8 Mounting hole 9 Land 10 Holder (theta) ₁ Tilt angle of a rake face ₂ Angular difference (theta) of the connection point of a rake face and a breaker wall ₃ Angle of intersection W with the reference surface of the breaker wall ₁ Distance from the cutting edge to the tip of the top of the breaker protrusion W ₂ Width of the rake face W ₃ Width of the land H Height from the cutting edge of the breaker protrusion A Reference plane

Claims

A cutting insert,
A rake face and a breaker projection formed on the rake face of the corner portion,
A cutting insert in which a breaker wall of the breaker projection is curved in a concave shape, and the rake face of the corner portion and a lower end of the breaker wall of the breaker projection are connected with an angle difference.
The cutting insert according to claim 1, wherein a land is provided on the rake face along the cutting edge.
The cutting insert according to claim 1 or 2, wherein a positive rake angle of 25 ° or less is given to the rake face.
The cutting insert according to any one of claims 1 to 3, wherein an angle difference of 5 ° or more is given to a connecting portion between the rake face and a breaker wall of the breaker protrusion.
The cutting insert according to any one of claims 1 to 4, wherein the width of the breaker from the scissors cutting edge to the tip of the top of the breaker protrusion is set in a range of 0.5 mm to 5.0 mm.
A cutting edge exchangeable cutting tool in which the cutting insert according to any one of claims 1 to 5 is detachably attached to the tip of a holder.