JPH0899202A - Insert for cutting - Google Patents

Abstract

PURPOSE: To improve contracting performance of chips by forming on a rake face lateral, inclined surfaces facing to each other on both sides of a central axis of an insert and a pair of chips-forming protrusions each having a front inclined surfaces facing toward almost the forward and dulling a rising angle of the lateral, inclined surface, thereby widening a groove between the protrusions. CONSTITUTION: Chips-forming-protrusions 4, 4 are provided with lateral sections 6, 6 facing to each other on both sides of a central axis of an insert 1 for cutting. A groove 7 between the protrusions, which is for discharging the chips and whose sectional form is almost of a letter-V, is formed between the protrusions 4 and 4. The protrusions 4, 4 are also provided with projected, front, inclined surfaces 8, 8 facing toward almost the forward. A rising angle of the lateral, inclined surfaces 6, 6 of the chips-forming protrusions 4, 4 is set at 30 deg. to 70 deg., thereby widening the groove between the protrusions 4, 4. In addition, the projected, front, inclined surfaces 8, 8 are of a recessed, curved surface in the axial direction or of a sphere, and moreover they are formed in such a manner that they rise at an angle of 130 deg. to 160 deg. in the central axis direction. With this, the surface to be machined will never be damaged, or the tip will never be broken because of jammed chips.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cutting insert used when cutting a metal material or the like.

[0002]

2. Description of the Related Art In cutting inserts for cutting metal materials, good chip disposal is necessary for work safety, prolonging tool life, suppressing cutting resistance and improving machining finish. is there. Therefore, in the above-mentioned cutting insert, various ones in which breaker protrusions of various shapes and forms and chip forming protrusions are formed on the rake face on which the cutting edge is formed have been used.

FIG. 7 shows such a conventional cutting insert, which has a cutting edge 22 on a top end 21 and a rake face 24 having a pair of chip forming projections 23, 23. In the cutting insert 20, the chip forming projections 23, 23 are provided with curved convex lateral slopes 25, 25 facing each other on both sides of the central axis of the insert and rising at a very steep angle. Is formed with an inter-projection groove 26 having a substantially V-shaped cross section, and is provided with concave front inclined surfaces 27, 27 which are oriented substantially forward and are concave in the central axis direction.

[0004]

However, the above-mentioned prior art has the following problems. That is, in the cutting insert 20, the chip forming projections 23, the convex lateral slopes 24 of the 23,
Since 24 has been formed as a curved surface which rises at a steep angle, next to a substantially V-shaped protrusions between the grooves 26 is narrow as shown in the sectional view of FIG. 8, thus squeezing the amount W over W ₁ of the chip is small, the groove There is a problem that the machined surface is scratched during the insertion process, and the chips are not formed in the shape of a spiral spring and are easily cut into small pieces, and are easily clogged. Therefore, there is a problem that the cutting resistance is very high because the chips flow while hitting the concave slopes 27, 27 over the entire surface.

[0005]

In order to solve the above-mentioned problems of the prior art, the cutting insert of the present invention has a pair of chip formations having a lateral slope facing both sides of the central axis of the insert and a front slope facing substantially forward. The protrusion is formed on the rake face, and the rising angle of the lateral slope is set to 30 °
By setting the angle to 70 °, the inter-projection groove is widened, while the front slope is concave in the axial direction and 13 in the central axis direction.
It was configured to stand up at an angle of 0 ° to 160 °.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 show a cutting insert 1 of this embodiment, which has a cutting edge at an upper end 2 and a rake face 5 having a pair of chip forming projections 4 and 4. The chip forming projections 4 and 4 are lateral slopes 6 facing each other on both sides of the central axis of the cutting insert 1,
The provision of 6 forms the inter-projection groove 7 having a substantially V-shaped cross-section for discharging chips between the projections, and also comprises the front convex slopes 8 and 8 which face generally forward.

In the chip forming projections 4 and 4, the inter-projection groove 7 is formed by setting the rising angle β of the lateral slopes 6 and 6 to 30 ° to 70 ° as shown in the partial sectional views of FIGS. 3 and 4. On the other hand, the convex front slopes 8 and 8 are made to be concave curved surfaces or spherical surfaces in the axial direction, and 13 in the central axis direction.
It is configured to rise at an angle of 0 ° to 160 ° (angle α: rising angle with respect to the horizontal direction when the cutting insert 1 is placed on a horizontal surface).

The cutting insert 1 thus constructed has the following actions. That is, in the above cutting insert 1, the chips cut by the cutting edge 3 hit the convex front projections of the chip forming projections 4 and 4 and receive upward stress, and the inter-projection groove 7 further forms a substantially V-shaped (U-shaped) cross section. While being squeezed into a shape), the cutting insert 1 is discharged in a spiral shape in the upper and rearward directions. Then, the lateral slopes 6, 6
By increasing the rising angle of 30 ° to 70 ° to widen the inter-projection groove 7, the central part of the chip deeply sinks, so the drawability becomes good, and the machined surface is scratched during the parting process. Moreover, since the chips are discharged in a good spiral shape, the chips are not clogged and the cutting edge is not damaged.

Further, in the above cutting insert 1, since the convex front slopes 8, 8 of the chip forming projections 4, 4 are made convex and rise at a relatively steep angle of 130 ° to 160 °, the chips are extremely damaged. Since the contact is made in a very narrow area, the cutting resistance is low, and stable chip disposal can be reliably performed up to a feed of at least ~ 0.20 mm / rev.

FIG. 5 shows a cutting insert 1 according to another embodiment of the present invention. In this cutting insert 1, the rear sides of the lateral slopes 6, 6 of the chip forming projections 4, 4 end in a semi-bowl shape. The structure is such that upward stress and drawing stress can be supplementarily applied to the chips.

Embodiment 1 In the cutting insert 1 shown in FIGS. 1 to 4, the lateral slopes 6, 6 of the chip forming projections 4, 4 have a rising angle β of 50 °, and the front slopes 8, 8 are convex. With the cutting insert 1 having the rising angle α of Table 1 as shown in Table 1, the cut-off processing was performed under the following conditions, and the formation state of chips was visually observed.

[Cutting Conditions] V = 150 m / min f = 0.10 mm / rev Wet SCM435 φ55 mm The results are shown in Table 1.

[0013]

[Table 1]

As is clear from Table 1, the rising angle α of the front slopes 8 of the chip forming projections 4 and 4 is 120 °.
, The springs of the chips are dense and the angle α is 1
At 70 °, the chips were not formed into a spring shape and were entangled with the holder, whereas 130 to 160 °
Then, it was discharged as a good spring. Also,
Regarding the presence or absence of blurring of the processed surface, the angle α is 130 ° to 16
In the case of 0 °, no blur of the processed surface occurred.

Therefore, it is preferable that the rising angle α of the front convex slopes 8 is 130 ° to 160 °.

Embodiment 2 In the cutting insert 1 shown in FIGS. 1 to 4, the rising angle α of the front slopes 8, 8 of the chip forming projections 4, 4 is increased.
Is 140 ° and the rising angle β of the lateral slopes 6, 6
Is subjected to grooving under the following conditions by using the cutting insert 1 as shown in Table 2, the drawing amount W-W ₁ of the chip 9 at the time of grooving as shown in FIG. 6 is measured, and the work 10 is processed. The state of the surface was observed.

[Cutting Conditions] V = 150 m / min f = 0.10 mm / rev Wet SCM435 φ55 mm The results are shown in Table 2.

[0018]

[Table 2]

As is clear from Table 2, the lateral slopes 6,
When the rising angle β of 6 is 20 °, the squeezing amount of chips is small and scratches are generated on the machined surface, and when it is 80 °, chips are finely cut and clogged and scratches are generated on the machined surface. When the rising angles β of 6 and 6 were 30 ° to 70, the amount of chip reduction was at least 0.1 mm and there was no scratch on the machined surface.

Therefore, it is preferable that the rising angle β of the lateral inclined surfaces 6, 6 is 30 ° to 70 °.

[0021]

As described above, the cutting insert of the present invention has a pair of chip forming projections formed on the rake face, each of which has a lateral slope facing both sides of the center axis of the insert and a front slope facing substantially forward. In addition, by widening the inter-protrusion groove by setting the rising angle of the lateral slope to be 30 ° to 70 ° which is loose, the drawability of chips is improved and the machined surface may be scratched in the parting process. Without
Further, since the chips are discharged in a good spiral shape, the chips are not clogged and the cutting edge is not damaged.

Further, in the above cutting insert, the front slope of the chip forming projection has a convex shape and is relatively steep.
Since the chips are made to rise at an angle of ° to 160 °, the chips come into contact with each other in a very narrow area, so that the cutting resistance is low, and stable chip disposal can be reliably performed up to a feed of at least ~ 0.20 mm / rev.

[Brief description of drawings]

FIG. 1 is a perspective view of a cutting insert according to an embodiment of the present invention.

2 is a top view of the cutting insert of FIG. 1. FIG.

FIG. 3 is an AA diagram of FIG.

FIG. 4 is a BB diagram of FIG.

FIG. 5 is a perspective view of a cutting insert according to another embodiment of the present invention.

FIG. 6 is a state diagram showing a state where parting processing is performed by the cutting insert of FIG. 1.

FIG. 7 is a perspective view of a conventional cutting insert.

FIG. 8 is a state diagram showing a state where parting processing is performed by a conventional cutting insert.

[Explanation of symbols]

 1 Cutting Insert 2 Top Edge 3 Cutting Edge 4 Chip Forming Protrusion 5 Rake Face 6 Lateral Slope 7 Inter-Protrusion Groove 8 Convex Front Slope 9 Chip 10 Workpiece α Convex Front Slope Rise Angle β Horizontal Slope Rise Angle

Claims (1)

[Claims] 1. A cutting insert having a cutting edge formed at an end of an upper surface and a rake face having a pair of chip forming projections, the chip forming projections facing each other on both sides of a central axis of the insert and at an angle of 30 °. A cutting insert having a lateral slope rising at an angle of ˜70 ° and a front convex slope rising at an angle of 130 ° to 160 ° in the central axis direction.