JPH0871806A - Throw-away insert for grooving - Google Patents

Abstract

(57) [Summary] [Object] To provide a throw-away tip for grooving which has a large cutting edge strength and can suppress the surface roughness of the cutting surface to a low level. [Structure] Rake face 1 provided with a cutting edge 11 on the tip ridge
In the throw-away tip 10 for grooving, in which back taper is formed on both side surfaces 14 continuous with 2,
A first back taper portion 14a having a taper angle of τ1 and a plan view length of L is formed in a region of the both side surfaces 14, 14 on the side of the cutting edge 11, and the first back taper portion 14 is formed.
A second back taper portion 14b having a taper angle τ2 larger than τ1 is formed in the region on the rear side of a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a grooving throw-away tip which is attached to a tool body by various methods to form a blade of a cutting machine and which is used for grooving a metal material.

[0002]

2. Description of the Related Art Recently, in the field of cutting metal materials,
A cutting machine in which a tip made of a hard material such as cemented carbide is detachably attached to a tool body made of steel is widely used. The tip used is a throw-away that is discarded along with the wear of the cutting edge of the tip. A lot of chips are used.

Of this type of throw-away tip, an example of a grooving throw-away tip used for grooving is shown in FIGS. In the figure, reference numeral 1
Is a throw-away tip for grooving (hereinafter abbreviated as a tip), and 2 is a work material. Cutting edges 3, 3, rake faces 4, 4 and flanks 5, 5 are formed at both ends of the tip 1. The rake face 4 is provided with a cutting edge 3 on its ridge, and both side faces 6 and 6 continuous with the rake face 4 are formed with a back taper with a taper angle τ as shown in the figure. The side surfaces 6, 6 are tapered surfaces approaching each other from the upper end to the lower end.

The chip 1 is attached to a shank (not shown) and is used for cutting. In FIGS. 9 and 10, when the work material 2 is rotated, the work surface 2 a is cut by the cutting edge 3.
Can be cut and the work material 2 can be cut. At this time,
Since the side surfaces 6 and 6 are back-tapered, the friction between the side surfaces 6 and 6 and the work side surfaces 2b and 2b is suppressed to be low, and the work material 2 can be cut.

[0005]

However, in the above-mentioned conventional tip 1, if the taper angle τ is too large, the ends 3a, 3a of the cutting edge 3 become sharp,
There arises a problem that stress during cutting tends to concentrate, causing a decrease in strength of the cutting edge 3 and increasing the surface roughness of the side surface 2b to be cut. On the contrary, if the taper angle τ is too small,
The friction between the side surfaces 6 and 6 and the side surfaces 2b, 2b to be machined becomes large, which causes a problem that the life of the tip 1 is shortened, and when the friction becomes large, chatter vibration due to imbalance of frictional force occurs. It will be easier. If chatter vibration occurs, the work surface 2a and the work side surface 2 which are cutting surfaces
The surface roughness of b will increase.

That is, in the conventional tip 1 described above, when determining the taper angle τ, it is necessary to optimally determine the taper angle τ so as not to be too large or too small in consideration of the above circumstances. Depending on cutting conditions such as
The optimum value of the taper angle τ changes each time, and it is difficult to find the optimum value.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a throw-away tip for grooving which has a large cutting edge strength and can suppress the surface roughness of the cutting surface to a low level. There is.

[0008]

In order to solve the above problems, the present invention employs the following configurations. That is, in the grooving throw-away tip according to claim 1, in the grooving throw-away tip having back taper formed on both side surfaces continuous with the rake face provided with a cutting edge on the tip ridge, A first back taper portion is formed in the cutting edge side regions of both side surfaces, and a second back taper portion having a taper angle larger than that of the first back taper portion is formed in a rear side region of the first back taper portion. It is characterized by being formed.

Further, in the indexable indexable cutting insert according to claim 2, in the indexable indexable indexable cutting insert according to claim 1, a chip breaker is formed on the rake face at a position separated from the cutting edge. A raised portion is provided, and both side surfaces of the raised portion are characterized by being upright with respect to the rake surface or being surfaces that incline toward each other as they rise.

According to a third aspect of the present invention, there is provided the grooving throwaway tip according to the first or second grooving throwaway tip, wherein the first back taper portion has a taper angle of 1 to 6 degrees. The taper angle of the second back taper portion is 2 to 8 degrees.

[0011]

In the indexable cutting insert according to the first aspect of the present invention, the first back taper portion is formed in the cutting edge side regions of both side surfaces continuous with the rake face, and the rear side of the first back taper portion is formed. A second back taper portion having a taper angle larger than that of the first back taper portion is formed in the region. Since the taper angle of the second back taper portion is large, it is possible to reduce friction between both side surfaces continuous with the rake surface and the side surface to be machined. Therefore, the taper angle of the first back taper portion can be set small. If the taper angle of the first back taper portion is small, the end portion of the cutting edge will not be sharpened, and stress during cutting will not be concentrated on the end portion of the cutting edge. Therefore, a large cutting edge strength can be obtained. On the contrary, since the strength of the cutting edge is secured by the first back taper portion, it is possible to set the taper angle of the second back taper portion to be large and reduce the friction.
That is, the first back taper portion plays a role of ensuring the strength of the cutting edge, and the second back taper portion plays a role of reducing friction.

In the grooving throw-away tip according to a second aspect of the present invention, since both side surfaces of the ridge portion are upright with respect to the rake surface or are surfaces that incline toward each other as they rise, the ridge portion is There is no contact with the side surface to be cut. Therefore, the ridge does not hinder cutting.

In the indexable insert for grooving according to the present invention, since the taper angle of the first back taper portion is as small as 1 to 6 degrees, the end of the cutting edge is not sharpened, and during cutting. Stress does not concentrate on the edge of the cutting edge. Therefore, a large cutting edge strength can be obtained. Also,
Since the taper angle is small, the surface roughness of the side surface to be cut can be kept low. Further, since the taper angle of the second back taper portion is 2 to 8 degrees and is larger than the taper angle of the first back taper portion, the friction between the opposite side surfaces of the rake surface and the side surface to be cut is small. small. Therefore, the life of the indexable insert for grooving can be extended. Further, since the friction is small, chatter vibration can be made difficult to occur.

[0014]

An embodiment of the present invention will be described below with reference to the drawings. 1, 2 and 3 show an embodiment of the indexable insert for grooving of the present invention. In the figure, reference numeral 1
Reference numeral 0 is a throw-away tip for grooving (hereinafter abbreviated as a tip), 11 is a cutting edge, 12 is a rake face, and 13 is a flank face. The rake face 12 has a cutting edge 11 on the tip ridge.
Provided on both sides 14 and 14 continuous with the rake face 12.
Is formed with a back taper. And the side surface 14
In the cutting edge 11 side region, a first back taper portion 14a having a taper angle of τ1 and a length L in plan view is formed, and in the rear side region of the first back taper portion 14a of the side surface 14. A second back taper portion 14b having a taper angle τ2 larger than that of the first back taper portion 14a is formed. Further, the side surfaces 14 and 14 are tapered surfaces approaching each other from the upper end to the lower end, as shown in FIGS.

Further, as shown in FIGS. 1, 2 and 3, a raised portion 15 forming a chip breaker is formed on the rake face 12 at a position separated from the cutting edge 11. Both side surfaces 16, 16 of the raised portion 15 are surfaces that stand upright with respect to the rake surface 12, as shown in FIG. In addition, a recess 17 is formed in the lower portion of the chip 10, and the protrusion 15 is formed.
Recesses 18 and 19 shown in FIGS. 6 and 7 are sequentially formed on the side opposite to the rake face 12.

The chip 10 having the above structure is, for example,
In FIG. 8, the hole 20a formed in the shank 20,
It is fitted in the recess 20a using the recesses 17 to 19. Then, the work material, the cutting edge 11 of the chip 10, the rake face 12,
The positional relationship with the flank 13 and the like is used for grooving the work material in the same manner as the conventional example.

In the chip 10, the rake face 12
The first back taper portions 14a, 14a are formed in the cutting edge 11 side regions of the both side surfaces 14, 14 continuous with the first back taper portions 14a in the rear side regions of the first back taper portions 14a, 14a. , 14a larger than 14a
Second back taper portions 14b, 14b having 2 are formed. Since the taper angle τ2 of the second back taper portion 14b is large, it is possible to reduce the friction between the side surfaces 14 and 14 continuous to the rake surface 12 and the side surface to be cut. Therefore, the taper angle τ1 of the first back taper portion 14a can be set small. If the taper angle τ1 of the first back taper portion 14a is small, the end 11a of the cutting edge 11 will not be sharpened, and the stress during cutting will not be concentrated on the end 11a of the cutting edge 11. Therefore,
A large strength of the cutting edge 11 can be obtained, and the surface roughness of the side surface to be cut can be suppressed low. On the contrary, since the strength of the cutting edge 11 is secured by the first back taper portion 14a, it is possible to reduce the friction by setting the taper angle τ2 of the second back taper portion 14b large. . Second
The larger the taper angle τ2 of the back taper portion 14b is,
Friction is reduced, and the life of the chip 10 can be extended. Further, since the friction is small, chatter vibration can be made difficult to occur.

That is, in the tip 10, the strength of the cutting edge 11 is secured by the first back taper portion 14a having a small taper angle τ1, and the rake is provided by the second back taper portion 14b having a large taper angle τ2. The first and second back taper portions 1 are provided to reduce friction between the side surfaces 14 continuous with the surface 12 and the side surface to be machined.
By using both 4a and 14b, it is possible to prevent the above-mentioned problems caused by the taper angle τ from becoming too large or too small. If the taper angles τ1 and τ2 are too large, the friction between the side surface 14 and the side surface to be machined becomes large, and if the taper angles are too small, it becomes difficult to secure the strength of the cutting edge 11,
The taper angle τ1 is preferably 1 to 6 degrees, and the taper angle τ2 is preferably 2 to 8 degrees.

Both side surfaces 16, 16 of the raised portion 15 are
Since the surface is upright with respect to the rake face 12, the raised portion 1
5 does not come into contact with the side surface to be cut, and the protrusion 15 does not interfere with cutting. Where the side faces 16, 1
Instead of making 6 upright with respect to the rake face 12,
The surfaces may be inclined inward with respect to each other as they stand up, and even in that case, the same effect as when standing upright can be obtained.

[0020]

According to the first aspect of the present invention, the first back taper portion is formed in the cutting edge side regions of both side surfaces continuous with the rake surface. A second back taper portion having a larger taper angle than the first back taper portion is formed in the rear side region of the. Therefore, the strength of the cutting edge is secured by the first back taper portion having a small taper angle, and the friction between the side surface and the side surface to be machined continuous to the rake surface is secured by the second back taper portion having a large taper angle. Can be reduced. Therefore, a large cutting edge strength can be obtained and the surface roughness of the cutting surface can be suppressed low.

According to the grooving throw-away tip of the present invention, both side surfaces of the raised portion are upright with respect to the rake face, or are surfaces that incline toward each other as they rise, so that the raised portion is raised. Does not contact the side surface to be cut. Therefore, the ridge does not hinder cutting.

According to the third aspect of the present invention, the first back taper portion has a taper angle of 1
Since it is as small as ~ 6 degrees, the end of the cutting blade will not be sharpened. Therefore, the stress during cutting does not concentrate on the end portion of the cutting edge, and thus a large strength of the cutting edge can be obtained.
Further, since the taper angle is small, the surface roughness of the side surface to be cut can be suppressed low. Further, since the taper angle of the second back taper portion is 2 to 8 degrees and is larger than the taper angle of the first back taper portion, the friction between the opposite side surfaces of the rake surface and the side surface to be cut is small. small. Therefore, the life of the indexable insert for grooving can be extended. Further, since the friction is small, chatter vibration can be made difficult to occur.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of a grooving throw-away tip of the present invention.

FIG. 2 is a front view of the indexable indexable cutting insert.

FIG. 3 is a side view of the grooveable indexable insert.

FIG. 4 is a cross-sectional view taken along the line AA in FIG. 2 of the same indexable indexable cutting insert.

FIG. 5 is a cross-sectional view taken along the line BB in FIG. 2 of the indexable insert for grooving.

FIG. 6 is a cross-sectional view taken along line C-C of FIG. 2 of the indexable insert for grooving.

FIG. 7 is a cross-sectional view taken along the line DD in FIG. 2 of the same groove cutting indexable insert.

FIG. 8 is an explanatory view showing an example of mounting the indexable indexable cutting insert to a shank.

FIG. 9 is a plan view showing a conventional example of a throw-away tip for grooving.

FIG. 10 is a front view of the indexable indexable cutting insert.

FIG. 11 is a side view of the grooveable indexable insert.

[Explanation of symbols]

 10 Groove Cutting Throw-away Tip 11 Cutting Edge 11a End 12 Rake Face 14 Side 14a First Back Tapered 14b Second Back Tapered 15 Raised 16 Side τ1 Taper Angle τ2 Tapered Angle L First Back Tapered Plan view length

Claims (3)

[Claims] 1. A furrow cutting insert for grooving in which a back taper is formed on both side surfaces continuous with a rake surface provided with a cutting edge on the tip ridge, and a first side is provided in a cutting edge side region of both side surfaces. A back taper portion is formed, and a second back taper portion having a taper angle larger than that of the first back taper portion is formed in a region on the rear side of the first back taper portion. Throw-away tip. 2. The throw-away tip for grooving according to claim 1, wherein the rake face is provided with a ridge forming a chip breaker at a position spaced from the cutting edge, and both side faces of the ridge are A throw-away tip for grooving, which is upright with respect to the rake face or is a face that is inclined inward with respect to each other as it rises. 3. The indexable insert for grooving according to claim 1 or 2, wherein the taper angle of the first back taper portion is 1 to 6 degrees, and the taper angle of the second back taper portion is , 2
Throw-away insert for grooving characterized by 8 degrees.