JPH02109612A - Throw away tip - Google Patents

Abstract

PURPOSE:To favorably dispose of chips and enable chamfering cutting by providing separate chip breakers in nose portions and side portions and forming nose cutting edge ridges and side cutting edge ridges on the contour ridges thereof. CONSTITUTION:Chip breakers 2 are formed on nose portions while forming chip breakers 3 on side portions, and nose cutting edge ridges 4a and side cutting edge ridges 4b are formed with their centers lowered toward a boss face 5 on contour ridges. The chip breaker 2 is formed with two different curvature radii R1, R2 in the bisector direction, being formed in a smooth continuing face of recessed curved faces, and a positive rake angle theta1 is formed on the curvature radius R1 side. In the chip breaker 3, a positive rake angle theta2 which is smaller than the rake angle theta1 of the chip breaker 2 is formed in a crossing direction from the side cutting edge ridge 4b to the center boss face 5. Thereby, chips can be effectively curled particularly by the center lowering structure while reducing cutting resistance by the structure of positive rake angles theta1, theta2, to obtain an excellent chip disposing property while enabling application also to special sue such as chamfering cutting, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an indexable tip equipped with a chip breaker, and is particularly suitable for use with difficult-to-cut materials such as stainless steel.

(Prior Art) Conventionally, one indexable tip of this type has been disclosed, for example, in Japanese Patent Application Laid-open No. 173104/1983. The indexable chip disclosed in this publication includes a first chip breaker in the nose portion and second chip breakers located on both sides of the first chip breaker.

(Problems to be Solved by the Invention) However, stainless steel cutting has problems such as easy welding of chips to the cutting edge and high cutting resistance. And, with the throw-away tip mentioned above,
These problems have been significantly improved.

On the other hand, recent trends call for better chip disposal properties and wider use in applications such as profiling and chamfering, and solving these problems has become a problem.

In view of the above, an object of the present invention is to provide an indexable insert which can be used for general purposes in cutting difficult-to-cut materials such as stainless steel, and which also has improved chip disposal properties.

(Means for Solving the Problems) The present invention has been made in view of the above points, and includes a first chip breaker in the nose portion and a second chip breaker in the side portion. An object of the present invention is to provide an improved indexable insert having a polygonal plate shape in which a nose cutting edge edge and a side cutting edge edge are configured by an outer edge.

That is, the nose cutting edge ridge and the side cutting edge ridge are arranged below the center of the center boss surface during cutting. This is to promote curling and breakage of chips from welding.

Further, in the first chip breaker, the concave curved surface has two different radii of curvature R+ toward the central boss surface when the bisector of the nose portion is used as a reference.

1 (consisting of 2, and whose radius of curvature R+
, R-, the center points Ot and Oa are on a common perpendicular line to the bisector, and the radius of curvature R+ forming the nose cutting edge ridge
On the side, a substantially positive rake angle θ1 is formed. This is a consideration for increasing the curl radius of chips by having two curvature radii R+ and Rs, thereby facilitating chip disposal.

Further, the @2 second chip breaker is connected to both sides of the first chip breaker and has a positive rake angle θ smaller than the rake angle θ in the transverse direction toward the central boss surface. is made up of. This is because the edge of the side cutting edge is used for profiling and chamfering for end surface drawing, so fracture resistance is enhanced.

(Function) The indexable insert of the present invention uses the first chip breaker to dispose of chips suitable for normal cutting, and the second chip breaker to perform cutting.

This is used to dispose of chips during end face drawing.

In addition, the indexable insert of the present invention effectively curls chips due to its downward core configuration.

Good chip disposal properties. Also, the positive rake angle θ
1. The configuration of θ is intended to reduce cutting resistance.

(Example) An example of the indexable chip of the present invention will be described below with reference to the drawings.

In FIGS. 1 to 4, (1) is an indexable tip having a substantially triangular root shape, and a first chip breaker (2) is formed in its nose portion, and its side portions are provided with a first chip breaker (2). , a second chip breaker (3) is formed.

The outer edge of the indexable tip +11 forms a nose cutting edge (4a) and a side cutting edge (4b), respectively.

Also, the central boss (5) of the throwaway chip (1)
A mounting hole (6) is drilled in the.

Therefore, the nose cutting edge ridge (4a) and the side cutting edge ridge (
4b) is one that is downwardly centered relative to the central boss surface (5) during cutting. This is shown in FIGS. 3 and 4 as core-downward clear δ (δ=0.2 mm in the example), and is a consideration to facilitate curling and breakage of chips.

As shown in FIG. 3, the first chip breaker (2) has two different radii of curvature R2R2 (in the case shown, R1<R2), as shown in FIG. ). In this case, the center point 01 of the radius of curvature R, and the center point 02 of the radius of curvature R2 are
Since a smooth connection of concave curved surfaces is required, it is located on a common perpendicular line (7) 1 from the bisector.

On the curvature radius R1 side, a positive rake angle θ1 is formed in a practical sense.

On the other hand, the second chip breaker (3) is connected to both sides of the first chip breaker (2), and is connected in the transverse direction from the cutting edge (4b) to the central boss surface (5). , the positive rake angle θ is smaller than the rake angle θ mentioned above.
3. For example, set θ2=13°. The reason for making it smaller was to increase the strength of the cutting edge. The second chip breaker (3) has a narrow breaker width in order to be applied to applications such as chamfer cutting and end face cutting. Also, the second
In the case shown in FIG. 1, the chip breaker (3) is wide at the connection part to the first chip breaker (2) and narrow at the center of the side. However, depending on the cutting conditions etc., it can be changed to a so-called parallel groove (not shown).

5 and 6 show modified examples.

In particular, inclination is not applied to the nose cutting edge ridge (4a) in order to improve fracture resistance. In order to avoid inclination, the third chip breaker (8) may be formed in the same cross-sectional direction as the appropriate cutting edge (4b).

The third chip breaker (8) is configured with a positive rake angle θ, as shown in the cross-sectional view in FIG. This rake angle θ is determined from the rake angle θ2 in order to smooth the connection with the second chip breaker (3) and from the relationship of sharpness, - for boat fishing, θ2
≦03.

Figure 8 is an explanatory diagram showing the chip processing range, and is based on the indexable tip (1) shown in Figure 5.
304 by cutting the outer periphery. In this case, the indexable tip (+1 tool specification is TPGTI6T30
4 as the basic shape, and for the first chip breaker (2), R+ = 2.8 mm, Rx = 3.2n
+m.

The breaker width W was set to 2.5 mm. Also, the second
For the chip breaker (3), the width of the connection part is set to 0.
, 7mm, the width of the center part of the side is 0°41. Rake angle θ2-I3°, third chip breaker (8) was set to rake angle θ = 18°.

Also, what is shown in FIG. 9 is the rake angle θ.

In order to make the angle gentler, the radius of curvature ' is more than R8.
The diameter R1 is set larger.

Therefore, regarding the chip disposal range mentioned in m1,
It is improved on the low feed side and low depth of cut side compared to the figure.

(Effects of the Invention) As described below, the present invention comprises a first chip breaker (2) and a second chip breaker (3), and is suitable for difficult-to-cut materials such as stainless steel. It is a specific shape. Therefore, it has excellent chip disposal properties and can be cut with a single chamfer.

It has the advantage of being applicable to special applications such as end face cutting.

[Brief explanation of drawings]

Fig. 1 is a plan view showing an embodiment of the indexable tip of the present invention, Fig. 2 is a side view thereof, and Fig. 3 is a partially enlarged view taken along line III-1■ in Fig. 1. A sectional view, FIG. 4 is a partial sectional view taken along +V-tvliI in FIG. 1, and FIG. 5 is a front view showing a modified example.
FIG. 6 is a side view thereof, FIG. 7 is a partially enlarged sectional view taken along the line ■-■ in FIG. 6, and FIG. FIG. 9 is a partially enlarged sectional view showing a modification of FIG. 3. +1 Throwaway insert 2) First chip breaker 3) Second chip breaker 4a) - Nose cutting edge (4b) - Appropriate cutting edge 5) Central boss Face (71...
Vertical line 8)...Third chip brake force day

Claims (3)

[Claims] (1) It has a polygonal plate shape, and its nose part is equipped with a first chip breaker (2), and its side parts are equipped with a second chip breaker (3), and the nose is cut by its outer edge. In the indexable tip configured with a blade ridge (4a) and a side cutting edge (4b), the nose cutting edge (4a) and the side cutting edge (4b) are
When cutting, the core is below the center boss surface (5), and when the first chip breaker (2) is based on the bisector of the nose portion, its concave curved surface is below the center boss surface (5).
5) Consisting of two different radii of curvature R_1, R_2 toward the side, and these radii of curvature R_1, R_
2 center points O_1 and O_2 are on a common perpendicular line (7) to the bisector, and on the side of the radius of curvature R_1 forming the nose cutting edge ridge (4a), a substantially positive rake angle θ_
1, and the second chip breaker (3) is connected to both sides of the first chip breaker (2) and has a central boss surface (
5) A throw-away tip characterized in that a positive rake angle θ_2 smaller than the rake angle θ_1 is formed in the transverse direction toward the direction 5). (2) The second chip breaker (3) has a parallel width, or the breaker width is wide at the connection part to the first chip breaker (2) and changes to become narrower at the center of the side. The indexable tip according to claim 1. (3) The cutting edge is such that the nose cutting edge (4a) and the side cutting edge (4b) are parallel to the central boss surface (5) when viewed from the side. Throwaway tips listed.