JP2003011017A - Throwaway tip - Google Patents

Abstract

PROBLEM TO BE SOLVED: To cut cutting chips in pieces stably without increasing cutting force. SOLUTION: Inclined faces 12A and 12A, which approach the side of a lower face 11 as approaching the corner sections 17A and 17B of a cutting edge 17, are formed at portions on both ends of an upper face 12 in its longitudinal direction. A serration 16 comprising a plurality of groove sections 14 and crest sections 15 arranged alternatively is formed on the upper face 12 excluding the inclined faces 12A and 12A. The groove sections 14 and the crest sections 15 of the serration 16 are made curved. When a tip 10 is secured to a tool body, the groove sections 14 and the crest sections 15 of the serration 16 are extended in the direction crossing the rotation axis of the tool body orthogonally.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a throw-away tip (hereinafter referred to as a tip) mounted on a throw-away type ball end mill or the like.

[0002]

2. Description of the Related Art Throw-away type ball end mills are
For example, a pair of chip pockets are formed on the tip of a substantially cylindrical tool body so as to sandwich the tool rotation axis, and a pair of chip pockets are formed on the opposite sides of the tool body. Chips are removably attached to the seats by clamp screws.

The tip mounted on the tip mounting seat is
Cutting blades each having a substantially quadrilateral arc shape are projected to the outer peripheral side of the tool body, and the rotation loci of the cutting blades are arranged so as to form one substantially spherical shape. In such a throw-away type ball end mill, cutting is usually performed using the entire length of the cutting edge, but by providing the cutting edge with a notch called a nick, the chips produced by the cutting edge are cut in the width direction. It is aimed at keeping the chip discharge property good by dividing it.

[0004]

However, when various work pieces having different inclination angles with respect to the tool rotation axis are cut by using the throw-away type ball end mill having the above-described structure, that is, various cutting operations are performed. When cutting in the direction, only a part of the cutting edge may be used for the cutting instead of the entire length of the cutting edge.In such a case, the nick formed on the cutting edge that is not used for cutting ,, it does not work at all.
Further, in the conventional nick formed on the cutting edge, there is a problem that the cutting resistance at the time of cutting increases and the sharpness decreases.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a throw-away tip capable of stably cutting chips without increasing cutting resistance.

[0006]

[Means for Solving the Problems] By solving the above problems,
In order to achieve such an object, the present invention has a substantially arcuate cutting edge formed on a side edge portion of an upper surface facing a lower surface which is a seating surface, and when mounted on a tool body, A throw-away tip in which the locus of rotation of the cutting edge forms a part of a substantially spherical surface, wherein serrations in which a plurality of groove portions and mountain portions are alternately arranged are formed on the upper surface. It is characterized in that the blade has a wavy shape. With such a configuration, the chips can be finely divided by the corrugated cutting blade formed on the side edge portion of the upper surface. Moreover, since the cutting edge has a corrugated shape over almost the entire length, even when only a part of the cutting edge is used for cutting in various cutting directions, the cutting edge used for this cutting is used. Since it has a wavy shape, chips can be stably divided. Also, since the corrugated cutting edge is composed of the serration groove and peaks, forming the groove parallel to the lower surface may increase cutting resistance like a nick. Absent.

Further, the present invention is characterized in that the groove portion and the mountain portion are formed by curved surfaces. With such a configuration, the cutting edge formed on the side edge portion of the upper surface of the tip also has a wavy shape formed by a curved line, so that the strength of the cutting edge can be secured.

Further, according to the present invention, the groove portion and the crest portion extend in a direction toward the outer circumferential side of the tool body as it goes toward the tip side of the tool body, or in a direction orthogonal to the tool rotation axis line to form a tool rotation axis line. On the other hand, the serration is formed so as to be inclined in the range of 30 ° to 90 °. Here, if the inclination angle with respect to the tool rotation axis in the direction in which the groove portion and the crest portion extend is too small, the portion of the cutting blade on the rear end side of the tool body will have a very gentle wavy shape. It may not be possible to divide the chips with the cutting edge on the end side.On the other hand, even if the angle of inclination with respect to the tool rotation axis is too large, the part of the cutting edge on the tip side of the tool body exhibits a very gentle wave shape. Similarly, there is a possibility that chips may not be cut by the cutting blade on the tip side of the tool body. Therefore, in the present invention, the inclination angle with respect to the tool rotation axis in the direction in which the groove portion and the crest portion extend is
By setting in the range of 30 ° to 90 °, it becomes possible to maintain an appropriate corrugated shape over the entire length of the cutting edge, and even when cutting in various cutting directions, the corrugated shape is formed. The cutting edge does not reduce the effect of finely dividing the chips.

Further, according to the present invention, when viewed in a cross section orthogonal to the direction in which the groove and the crest extend, the distance in the thickness direction of the throw-away tip between the bottom of the groove and the apex of the crest is: It is characterized in that it is set in the range of 0.3 mm to 1.2 mm. Here, if the distance between the bottom of the groove and the apex of the crest is too small, the cutting edge formed on the side twill of the upper surface has a substantially linear shape, and the corrugated cutting edge may not be able to divide the chips. On the other hand, even if the distance between the bottom of the groove and the apex of the crest is too large, the cutting edge formed on the side twill of the upper surface has a wavy shape with a very large height difference, and Will lead to a decline. Therefore, in the present invention, the distance between the bottom of the groove and the apex of the peak is 0.3 mm to 1.2 m.
By setting in the range of m, it is possible to stably divide the chips without lowering the strength of the cutting edge.

Further, according to the present invention, when viewed in a cross section orthogonal to the direction in which the groove portion and the mountain portion extend, the distance between the vertices of the mountain portion is set in the range of 2.0 mm to 10.0 mm. It is characterized by being. Here, if the distance between the peaks of the peaks is too small, the cutting edge formed on the side twill of the upper surface has a very fine wavy shape, while the distance between the peaks of the peaks is too large. However, since the cutting edge formed on the side twill portion of the upper surface has a very gentle wave shape, there is a possibility that the chips cannot be divided. Therefore, in the present invention, the distance between the vertices of the mountain portion is 2.0
By setting in the range of mm to 10.0 mm, it becomes possible to stably divide the chips.

Further, according to the present invention, when viewed in a cross section orthogonal to the direction in which the groove portion and the mountain portion extend, the groove portion and the mountain portion have a radius of curvature in the range of 2.0 mm to 10.0 mm. It is characterized in that it is formed in a curved shape. Here, if the radius of curvature of the groove portion and the mountain portion formed in the curved section is too small, the groove portion and the mountain portion become too sharp, and the cutting edge formed on the side twill portion of the upper surface also exhibits the same wavy shape. Therefore, there is a possibility that the strength of the cutting edge may not be ensured. On the other hand, if the radius of curvature of the groove portion and the mountain portion which are formed in a curved section is too large, the groove portion and the mountain portion are formed in a very gentle curved shape,
Since the corrugation of the cutting edge formed on the side twill portion of the upper surface also has a very gentle shape, it is difficult to obtain the effect of dividing the chips. Therefore, in the present invention, the groove portion and the mountain portion are referred to as 2.
By forming the curved shape with the radius of curvature of 0 mm to 10.0 mm, it is possible to maintain the cutting edge strength and to maintain the good effect of dividing the chips.

Further, according to the present invention, when viewed in a cross section orthogonal to a direction in which the groove portion and the crest portion extend, a tangent line at an intersecting portion between the crest portion and the groove portion adjacent to the tip end side of the tool body is the lower surface. And the absolute value of the inclination angle formed by the tangent line at the intersection of the crest portion and the groove portion adjacent to the tool body rear end side with respect to the lower surface are different from each other. It is characterized by being With such a configuration, it becomes possible to design the corrugated cutting edge formed on the side edge portion of the upper surface into a desired shape, and it is possible to obtain a cutting edge having various characteristics depending on the cutting situation. Become. Particularly, at this time, the absolute value of the inclination angle formed by the tangent line at the intersection of the crest portion and the groove portion adjacent to the tool body tip side with respect to the lower surface is the crest portion and the tool body rear end side. If the tangent at the intersection with the adjacent groove is made larger than the absolute value of the angle of inclination with respect to the lower surface, the crest of the cutting edge and the groove adjacent to the tool body tip side thereof Between the part, that is, while reducing the length of the cutting edge having a negative axial rake when the tip is mounted on the tool body, between the crest part of the cutting edge and the groove part adjacent to the tool body rear end side. Since the length of the portion between them, that is, the cutting edge having a positive axial rake when the tip is mounted on the tool body can be increased, it is possible to maintain the sharpness of the cutting edge.

Further, the present invention is characterized in that the intersecting portion of the groove portion and the mountain portion is formed by a flat surface. With such a configuration, it becomes possible to design the corrugated cutting edge formed on the side edge portion of the upper surface into a desired shape, and it is possible to obtain a cutting edge having various characteristics depending on the cutting situation. Become.

Further, according to the present invention, the upper surface connected to the tip portion of the cutting blade is an inclined surface which gradually approaches the lower surface as it goes toward the tip of the cutting blade. The serration is formed. With such a configuration, the peripheral speed is low, the cutting edge angle of the cutting edge that receives a large cutting load can be increased, and serrations are formed on the upper surface of the part where the thickness of the tip is thin due to the inclined surface. It does not reduce the rigidity of the chip.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A chip according to an embodiment of the present invention will be described below with reference to the accompanying drawings. 1 is a perspective view of a chip according to a first embodiment of the present invention, FIG. 2 is a top view of the chip, FIG. 3 is a view of the chip in the direction of arrow A, and FIG. 4 is a view of the chip in the direction of arrow B. 5 is a cross-sectional view taken along the line CC of the same chip.

The chip 10 according to the first embodiment is made of a hard material such as cemented carbide and has a structure as shown in FIGS.
As shown in FIG. 2, a side surface which is a leaf-shaped plate and is provided with an upper surface 12 which is a rake surface facing a lower surface 11 which is a seating surface when the tool body is mounted, and which is a flank surface. 13 is provided so as to be gradually inclined outward from the lower surface 11 toward the upper surface 12, and is a positive chip. The side surface 13 which is the flank includes the first flank surface 13A located on the upper surface 12 side of the chip 10 and the lower surface 11 of the chip 10.
It is located on the side and has a second flank 13B having a larger inclination than the first flank 13A.

An insert hole 19 for clamping screws is formed in the chip 10 from the central portion of the upper surface 12 through the lower surface 11, and the lower surface 11 intersects the longitudinal direction of the insert hole 19. For example, two key grooves 18, 18 are formed in the front and rear. As shown in FIGS. 1 and 2, a pair of approximately 1/4 arc-shaped cutting blades 1 are provided on the side edge portion of the upper surface 12 of the tip 10.
7, 17 are formed so as to be located on opposite sides of each other with the insertion hole 19 interposed therebetween. These cutting blades 17, 17 are formed so as to be point-symmetric with respect to the center of the tip 10 in a plan view, and are designed so that one tip can be used twice.

Further, the both end portions of the upper surface 12 in the longitudinal direction thereof come closer to the lower surface 11 of the chip 10 toward the tip corner portion 17A and the rear end corner portion 17B side of one cutting blade 17, respectively. Thus, the two inclined surfaces 12A and 12A that are inclined are formed. By forming the inclined surfaces 12A and 12A on the upper surface 12, one of the cutting blades 17 is provided with a corner portion 17A side at the tip thereof.
The arc-shaped first inclined cutting edge 17 inclined so that the distance from the lower surface 11 increases as the distance from the corner portion 17A increases.
C is formed, and a second inclined cutting edge 17D is formed on the side of the corner portion 17B at the rear end, which is inclined so that the distance from the lower surface 11 increases as the distance from the corner portion 17B increases. Further, the other cutting edge 17 is also formed with an arcuate first inclined cutting edge 17C and a second inclined cutting edge 17D, and has the same configuration as the one cutting edge 17.

On the upper surface 12 excluding the inclined surfaces 12A, 12A, a plurality of grooves 14 and crests 15 are alternately arranged so as to extend in a direction intersecting the longitudinal direction of the chip 10. 16 are formed, and the plurality of groove portions 14 and the mountain portions 15 are parallel to each other and are arranged at substantially equal intervals.
4 is formed so as to be parallel to the lower surface 11. Further, the plurality of groove portions 14 and the ridge portions 15 which form the serration 16 are each configured by a smooth curved surface and are smoothly connected to each other. Furthermore, the plurality of groove portions 14 and the ridge portions 15 of the serration 16 are The cutting blades 17 are formed so as to extend to the substantially arcuate cutting blades 17 formed on the side ridges of the upper surface 12, and substantially the entire length of the cutting blades 17 (first inclined cutting blade 17C, second inclined cutting blade 17D Except for the cutting edge 17), as shown in FIGS. 3 and 4, the cutting edge 17) has a wavy shape formed by a smooth curve in a side view.

Here, the shapes of the groove portion 14 and the mountain portion 15 of the serration 16 will be described in detail. As shown in FIG. 5, when viewed in a cross section orthogonal to the extending direction of the groove portion 14 and the mountain portion 15, the mountain portion The portion 15 is formed in a curved shape having a radius of curvature a that is convex from the lower surface 11 toward the upper surface 12 side (upper side in FIG. 5), and the groove portion 14 is formed from the upper surface 12 toward the lower surface 11 side (lower side in FIG. 5). It is formed in a curved shape having a curvature radius b which is concave toward the outside, and the curved groove portion 14 and the mountain portion 15 are smoothly connected to each other to form a corrugated cutting edge 17. The radius of curvature a of the mountain portion 15 is set in the range of 2.0 mm to 10.0 mm,
Moreover, the radius of curvature b of the groove portion 14 is 2.0 mm to 10.0.
It is set in the range of mm, and the relationship between these radii of curvature a and b is a> b.

The apex 15A of the ridge 15 and the groove 14
The distance h from the bottom 14A of the chip 10 in the thickness direction of the chip 10, that is, in the direction orthogonal to the lower surface 11, is 0.3 mm to 1.
It is set in the range of 2 mm. Further, the distance p between the vertices 15A of the adjacent mountain portions 15, that is, the pitch between the mountain portions 15 is set in the range of 2.0 mm to 10.0 mm. The distance between the bottoms 14A of the groove 14 is also the same as the distance p between the vertices 15A of the peaks 15.

Further, the ridge portion 15 and the tip of the one cutting edge 17 on the corner portion 17A side (the left side in FIG. 5,
The tangent line S1 at the intersection X1 with the groove portion 14 adjacent to the tip of the tool body 20 when the tip 10 is attached to the tool body 20 forms an inclination angle α with respect to the lower surface 11 (the tip of one cutting edge 17). Assuming that the direction inclining away from the lower surface 11 toward the corner portion 17A side is positive, the absolute value of α <0 °) and the peak portion 15 and the corner portion at the rear end of the one cutting edge 17 are formed. 17B side (right side in FIG. 5,
The inclination angle β (β> 0) formed by the tangent line S2 at the intersection X2 with the groove 14 adjacent to the tool body 20 at the rear end side when the chip 10 is mounted on the tool body 20.
The absolute value of () is the same (α = -β). Therefore, in FIG. 5, the mountain portion 15 is formed symmetrically on both sides with the apex 15A as a boundary, and the groove portion 14 is also formed symmetrically on both sides with the bottom 14A as a boundary.

Since the cross sections of the groove portion 14 and the crest portion 15 of the serration 16 are formed as described above, the cutting edge 17 formed in a corrugated shape by the groove portion 14 and the crest portion 15 is referred to as the groove portion 14. The side surface 13 extends in the direction in which the mountain portion 15 extends.
When viewed from the direction opposite to, that is, when viewed in the direction of the arrow A in FIG. 1 (FIG. 3), the cutting edge 17 has the same wavy shape as that shown in FIG.

The tip 10 according to the first embodiment has the above-described structure. Next, a two-blade throw-away type ball end mill having a plurality of, for example, two tips 10 mounted thereon will be described with reference to FIGS. This will be described with reference to FIG. FIG. 6A is a plan view of a throw-away end mill to which the tip of the first embodiment is attached, FIG. 6B is a front end view of the end mill, and FIG. 7 is a side view of the end mill.

In the throw-away type ball end mill according to the first embodiment, the tip portion 21 of the tool body 20 having a substantially cylindrical shape rotated about the tool rotation axis O has a substantially hemispherical shape. When viewed from the direction of the tool rotation axis O, the tool rotation axis O is sandwiched between the opposite sides of the tool rotation axis O as shown in FIG.
As shown in (b), a pair of chip pockets 22A and 22B are formed so as to be cut out at a right angle, and the tool pockets 22A and 22B are formed on the wall surfaces of the chip pockets 22A and 22B facing the tool rotation direction T forward. Chip mounting seats 23, 23 are formed on the tip side.

The tip mounting seats 23, 23 provided on the tip side of the tool body of the tip pockets 22A, 22B are moved backward from the wall surface of the tip pockets 22A, 22B toward the rear side in the tool rotation direction T to the outer peripheral surface of the tip portion 21. Planar bottom surface 2 that intersects with each other and has two keys 23C and 23C
3A and a wall surface 23B standing upright from the bottom surface 23A. Further, the bottom surfaces 23A, 23A of the tip mounting seats 23, 23 are formed so as to incline rearward in the tool rotation direction T toward the rear end side of the tool body as shown in FIG.

Now, the chip 10 according to the first embodiment.
In the tip mounting seat 23 on the tip side of the tool body of one of the tip pockets 22A, the upper surface 12 is directed toward the front side in the tool rotation direction T, and the side surface 13 connected to the other cutting edge 17 is brought into contact with the wall surface 23B. The corner portion 17A at the tip of one of the cutting blades 17 is positioned on the tool rotation axis O, and one cutting blade 17 is arranged so as to extend to the outer peripheral side of the tool body rear end, and The cutting blade 17 is attached by the clamp screw 24 so that the rotation locus of the cutting blade 17 around the tool rotation axis O is substantially hemispherical. Also, the keys 23C, 23C formed on the bottom surface 23A of the chip mounting seat 23
Engage with the key grooves 18, 18 of the chip 10 to prevent the chip 10 from being displaced.

At this time, the groove portion 14 and the crest portion 15 of the serration 16 formed on the upper surface 12 of the tip 10 extend in the direction orthogonal to the tool rotation axis O, and the inclination angle θ with respect to the tool rotation axis O becomes Tip 1 at 90 °
0 is installed. Also, the first inclined cutting edge 1 of the cutting edge 17
7C is set to a negative whose rake angle is negative. Further, on the cutting edge 17, the portion between the crest portion 15 and the groove portion 14 adjacent to the tip end side of the tool body thereof has the negative axial rake, and is adjacent to the crest portion 15 and the rear end side of the tool body. The portion between the groove 14 and the axial rake is set to be positive. That is, the corrugated cutting edge 17 is formed so as to have an axial rake in which negative and positive are sequentially repeated from the front end side to the rear end side of the tool body.

The tip 30 mounted on the tip mounting seat 23 on the tip side of the tool body of the other tip pocket 22B.
Is substantially the same shape as the tip 10 according to the first embodiment, and is formed slightly smaller. As shown in FIG. 6, the corner portion 37A at the tip of the cutting edge 37 of the tip 30 has the first embodiment. Is located slightly on the outer peripheral side of the tool body from the corner portion 17A at the tip of the cutting blade 17 of the tip 10, from which the cutting edge 37 extends to the outer peripheral side of the tool body rear end. The rotation locus around the tool rotation axis O is the cutting edge 17 of the tip 10 according to the first embodiment.
It is arranged so as to overlap the rotation locus of.

At this time, the positions where the rotation loci of the respective groove portions 14 formed by the cutting edge 17 of the chip 10 around the tool rotation axis O pass, and the positions of the tool rotational axis O of the mountain portions 15 formed by the cutting edge 37 of the chip 30. Of the cutting edge 17 of the insert 10 and the position of the cutting edge 37 of the insert 30 of the cutting edge 17 of the insert 10 and the cutting edge 37 of the insert 30. The position where the rotation locus of the groove 14 around the tool rotation axis O passes is the same. Here, with respect to the chips 10 and 30, the side surface 13 thereof is the upper surface 1
Since the positive tip gradually inwardly inclines from 2 to the lower surface 11 side, when the cutting edge 17 is viewed from the direction facing the upper surface 12, the cutting edge 17 has a gentle wave shape. , Chips 10 and 3 as described above
Since 0 is mounted, it is cut by the groove portion 14 and the crest portion 15 of the cutting edge 17 having the gentle wavy shape of the tip 10 to form a gently wavy processed surface also including the groove portion and the crest portion. If the cutting edge 37 of the tip 30 is used to cut the workpiece 10 after the tip 10, the peaks on the processing surface of the workpiece will be cut by the peaks 15 of the cutting edge 37 of the tip 30. It does not reduce the surface roughness of the machined surface.

The first book having the structure as described above
According to the chip 10 according to the embodiment, the serration 16 including the plurality of grooves 14 and the peaks 15 on the upper surface 12 is provided.
Since it is formed and has the corrugated cutting blade 17, the corrugated cutting blade 17 can finely divide the chips. Moreover, since the cutting edge 17 has a corrugated shape over substantially the entire length, even when only a part of the cutting edge 17 is used for cutting in various cutting directions, Since the provided cutting edge 17 has a corrugated shape, the chips can be stably divided, and the chip discharging property can be kept good. Moreover, since the groove portion 14 of the serration 16 is formed in parallel with the lower surface 11, the cutting resistance does not increase unlike the nick. In addition, the groove portion 14 of the cutting edge 17 and the mountain portion 1
5, it is possible to reduce the cutting resistance also by shifting the timing when biting into the work.

Further, since the groove portion 14 and the mountain portion 15 of the serration 16 are formed by curved surfaces, the upper surface 1
The cutting edge 17 formed at the edge portion of the second side also has a corrugated shape constituted by a curved line, and the strength of the cutting edge 17 can be secured.

Further, since the serrations 16 are formed so that the groove portions 14 and the crest portions 15 extend in the direction orthogonal to the tool rotation axis O, even when cutting is performed in various cutting directions, the corrugations are formed. The shape of the cutting blade 17 does not reduce the effect of finely cutting chips,
In particular, it is suitable when the feed is given in the direction orthogonal to the tool rotation axis O.

Furthermore, when viewed in a cross section orthogonal to the direction in which the groove 14 and the crest 15 extend, the distance h between the bottom 14A of the groove 14 and the apex 15A of the crest 15 in the thickness direction of the chip 10 is h.
Is too small, the cutting edge 17 formed in a corrugated shape by the groove portion 14 and the crest portion 15 becomes substantially linear, and there is a possibility that the cutting edge 17 cannot divide the chips. On the other hand, even if the distance h is too large, the cutting blade 17
Results in a corrugated shape with a very large difference in height, resulting in a reduction in cutting edge strength. Therefore, the first book
In the embodiment, the distance h is set to an appropriate range of 0.3 mm to 1.2 mm, so that it is possible to obtain the cutting edge 17 that can stably divide the chips while ensuring the cutting edge strength. it can.

Similarly, when viewed in a cross section orthogonal to the direction in which the groove 14 and the crest 15 extend, if the distance p between the apexes 15A of the adjacent crests 15 is too small, the cutting edge 17 is formed.
Has a very fine wavy shape, and on the other hand, even if the distance p is too large, the cutting edge 17 has a very gentle wavy shape, and there is a possibility that the chips cannot be divided. . Therefore, in the first embodiment, the distance p is set to an appropriate range of 2.0 mm to 10.0 mm, so that the chips can be stably divided by the cutting blade 17.

Further, similarly, when viewed in a cross section orthogonal to the direction in which the groove portion 14 and the mountain portion 15 extend, if the respective curvature radii a and b of the groove portion 14 and the mountain portion 15 having a curved cross section are too small, The groove portion 14 and the crest portion 15 become too sharp, and the cutting edge 17 formed in a corrugated shape by the groove portion 14 and the crest portion 15 also has the same shape, which may make it impossible to secure the cutting edge strength. On the other hand, even if the radii of curvature a and b are too large, the cutting edge 17 has a very gentle corrugated shape, so that it is difficult to obtain the effect of dividing the chips. Therefore, in the first embodiment, the groove 14
By forming the peak portion 15 and the mountain portion 15 in a curved sectional shape with a radius of curvature a and b of 2.0 mm to 10.0 mm, respectively, while maintaining the cutting edge strength, the effect of dividing the chips is kept good. You can

Further, since the inclined surfaces 12A and 12A are formed on the upper surface 12, the first inclined cutting edge 17C located at the corner portion 17A at the tip of the cutting edge 17 is provided, and the peripheral speed is small. , A cutting edge 17 that receives a large cutting load
It is possible to secure a large cutting edge angle at the tip portion of the tip 10, and the serrations 16 are not formed on the upper surface 12 of the portion where the thickness of the tip 10 is thinned by the inclined surface 12A.
The rigidity of can be kept high. However, in the first embodiment, the inclined surfaces 12A and 12A are formed at both ends of the upper surface 12 of the chip 10 in the longitudinal direction,
The inclined surfaces 12A, 12A may not be formed when the thickness of the chip 10 can be sufficiently large.

In the first embodiment of the present invention,
In the cross section of the groove portion 14 and the crest portion 15 in the serration 16 which are orthogonal to the extending direction thereof, the intersection portion X between the crest portion 15 and the groove portion 14 adjacent to the tool body tip side thereof.
1 and the absolute value of the inclination angle α of the tangent line S1 and the intersection X between the crest 15 and the groove 14 adjacent to the tool body rear end side.
Although the absolute value of the inclination angle β of the tangent line S2 in 2 is the same, these inclination angles α and β may be different from each other. For example, as in the first modified example shown in FIG. 8, the inclination angle α of the tangent line S1 with respect to the lower surface 11 at the intersection X1 between the crest 15 and the groove 14 adjacent to the tool body tip side (left side in FIG. 8) thereof. The serration is set so that the absolute value is larger than the absolute value of the inclination angle β of the tangent line S2 with respect to the lower surface 11 at the intersection X2 between the mountain portion 15 and the groove portion 14 adjacent to the tool body rear end side (right side in FIG. 8). 1
6 may be formed.

With this structure, the crest 15 on the cutting edge 17 and the groove 14 adjacent to the tip side of the tool body.
Between the cutting edge 17, that is, when the tip 10 is mounted on the tool body 20, the length of the cutting edge 17 set to the negative axial rake is reduced, and the peak portion 15 and the peak portion 15 on the cutting edge 17 are provided. Groove 1 adjacent to the rear end of the tool body
4, the tip 10 is the tool body 20.
When mounted on the, the length of the cutting blade 17 set to the positive axial rake can be secured to be large, and thus the sharpness of the corrugated cutting blade 17 can be kept good.

When the inclination angles α and β are different from each other, as in the above-described first embodiment, the plurality of groove portions 14 and the mountain portions 15 are arranged in a direction intersecting the longitudinal direction of the upper surface 12 of the chip 10. Serration 16 extending
If a pair of cutting edges 17, 17 formed on the side edge of the upper surface 12 are formed in a wavy shape so that one tip can be used twice, one cutting edge 17 The other cutting edge 17 has a diametrically opposite shape when attached to the tool body 20 (the absolute value of the inclination angle α of the one cutting edge 17 is the inclination angle β of the other cutting edge 17). The absolute value of the inclination angle β of the one cutting edge 17 becomes the same as the absolute value of the inclination angle α of the other cutting edge 17). In such a case, for example, the serrations 16 are not formed in the central portion of the upper surface 12 of the tip 10, and the upper surface 1 around each of the pair of cutting edges 17 is formed.
If the serration 16 having a desired shape is formed on only two, it is possible to cope with it.
Alternatively, whichever of the other cutting edge 17 is used, the cutting edge 17 having a desired shape can be used for cutting.

Further, as in the first embodiment,
The groove portion 14 and the crest portion 15 in the serration 16 are each formed by a curved surface, and the groove portion 14 and the crest portion 15 forming the curved surface are not connected to each other to form the corrugated cutting edge 17. The intersecting portion of the groove portion 14 and the mountain portion 15 is formed by a flat surface, and the groove portion 14 and the mountain portion 1
The curved groove portion 14 and the curved mountain portion 15 may be smoothly connected via a straight line portion in a cross section orthogonal to the direction in which 5 extends. For example, as in the second modified example shown in FIG. 9, the serration 16 in the first modified example may be configured such that the groove portion 14 and the mountain portion 15 are connected via the linear portion 16A. With such a configuration, it is possible to obtain the corrugated cutting edge 17 having optimum characteristics according to the expected cutting situation. In this case, the tangent lines S1 and S2 are the groove portions 1
It is the same as the straight line portion 16A connecting the 4 and the mountain portion 15.

Next, a second embodiment of the present invention will be described. The same parts as those in the first embodiment described above are designated by the same reference numerals and the description thereof will be omitted. 10 is a perspective view of a tip according to the second embodiment, FIG. 11 is a top view of the tip, and FIG. 12 is a plan view of a throw-away type ball end mill to which the tip is mounted.

The chip 40 according to the second embodiment has the same structure as that of the above-described first embodiment. The difference is that the groove portion 14 and the mountain portion 1 in the serration 16 are different.
5 is the direction in which they extend. That is, FIGS.
As shown in, when the tip 40 is mounted on the tool body 20, the groove portion 14 and the mountain portion 15 forming the serration 16 extend in the direction toward the tool body outer peripheral side according to the tool body tip side. The inclination angle θ with respect to the tool rotation axis O is set in the range of 30 ° to 90 °. In the second embodiment, for example, the groove 14 and the crest 15 are aligned with the tool rotation axis O. On the other hand, a tilt angle θ of 45 °
The serration 16 is formed so as to have. In the second embodiment, the inclined surface 12 on the upper surface 12
The serration 16 is formed up to A.

The chip 4 according to the second embodiment as described above.
According to 0, in addition to the effects described above, the inclination angle θ with respect to the tool rotation axis O in the direction in which the groove portion 14 and the crest portion 15 extend is set in the range of 30 ° to 90 °. It becomes possible to maintain an appropriate corrugated shape over the entire length of the blade 17, and even when cutting in various cutting directions, the effect of finely cutting chips by the corrugated cutting blade 17 is reduced. There is no end. Here, if the inclination angle θ with respect to the tool rotation axis O in the direction in which the groove portion 14 and the crest portion 15 extend is too small, the portion of the cutting edge 17 on the rear end side of the tool body will have a very gentle wave shape. However, if the cutting edge 17 on the rear end side of the tool body may not be able to divide the chips, and if the inclination angle θ is too large, the part of the cutting edge 17 on the tip side of the tool body will have a very gentle wave shape. Similarly, the cutting edge 17 on the tip side of the tool body may not be able to divide the chips.

Also in the second embodiment as described above, the groove portion 14 and the mountain portion 1 forming the serration 16 are the same as in the first and second modified examples of the first embodiment described above.
Of course, 5 may be shaped as shown in FIGS. 8 and 9.

Also, the plurality of groove portions 14 of the serration 16
The shape of the mountain portion 15 is not limited to the shape described in each of the above-described embodiments, and may be arbitrarily set as long as it can divide the chips generated by the cutting blade 17.
Further, although the tip 10 having a pair of cutting blades 17 and 17 and having a substantially tree leaf shape is used, the cutting blade is not limited to this, and the cutting blade is formed only on one side of the tip. A chip may be used.

[0047]

According to the present invention, serrations in which a plurality of grooves and peaks are alternately arranged are formed on the upper surface of the chip, and the cutting edge has a wavy shape. The blade allows the chips to be finely divided. Moreover, since the cutting edge has a corrugated shape over substantially the entire length, even when only a part of the cutting edge is used for cutting in various cutting directions, the cutting edge used for this cutting is By having a corrugated shape, the chips can be stably divided and the chip discharging property can be kept good. Further, if the groove portion of the serration is formed substantially parallel to the lower surface, the cutting resistance does not increase unlike a nick.

Further, since the groove portion and the crest portion of the serration are formed by the curved surface, the cutting edge formed on the side edge portion of the upper surface of the chip also has a wavy shape formed by the curved line, and the strength of the cutting edge is increased. Can be secured. Further, since the inclination angle formed by the groove portion and the crest portion with respect to the tool rotation axis is set in the range of 30 ° to 90 °, it is possible to maintain an appropriate corrugated shape over the entire length of the cutting edge. It becomes possible, and the effect of finely cutting the chips by the corrugated cutting blade in all cutting directions is not reduced.

The distance between the bottom of the groove and the top of the peak is
By setting the range of 0.3 mm to 1.2 mm,
It is possible to stably divide the chips without lowering the cutting edge strength or increasing the cutting resistance. Further, by setting the distance between the vertices of the ridges in the range of 2.0 mm to 10.0 mm, it becomes possible to stably divide the chips. In addition, the groove portion and the mountain portion, 2.0mm ~
By forming the curved shape with a radius of curvature of 10.0 mm, it is possible to maintain the cutting edge strength and at the same time maintain a good effect of dividing the chips.

Further, the absolute value of the inclination angle formed by the tangent line at the intersection of the crest portion and the groove portion adjacent to the tip end side of the tool body and the intersection portion of the crest portion and the groove portion adjacent to the rear end side of the tool body. Since the absolute value of the inclination angle formed by the tangent line is different from each other, it becomes possible to design the corrugated cutting edge formed on the side ridge of the upper surface into a desired shape, and to change it depending on the cutting situation. It becomes possible to obtain a cutting edge having characteristics. Particularly, the absolute value of the inclination angle formed by the tangent line at the intersection of the crest portion and the groove portion adjacent to the tool body tip side is the absolute value of the tangent line at the intersection portion of the crest portion and the groove portion adjacent to the tool body rear end side. If it is set to be larger than the absolute value of the inclination angle, the length of the cutting edge having the negative axial rake can be reduced and the length of the cutting edge having the positive axial rake can be increased. It is possible to keep the sharpness of the.

Further, since the intersecting portion of the groove portion and the mountain portion is formed by a flat surface, it becomes possible to design the corrugated cutting edge formed on the side ridge portion of the upper surface into a desired shape, and It is possible to obtain a cutting edge having optimum characteristics depending on the situation.

Further, since the inclined surface is formed on the upper surface of the tip and the serration is formed on the upper surface excluding this inclined surface, the peripheral speed is small and the tip portion of the cutting edge which receives a large cutting load is A large cutting edge angle can be secured, and serrations are not formed on the upper surface of the portion where the thickness of the tip is thin due to the inclined surface, and the rigidity of the tip can be kept high.

[Brief description of drawings]

FIG. 1 is a perspective view of a chip according to a first exemplary embodiment of the present invention.

FIG. 2 is a top view of the chip according to the first embodiment of the present invention.

FIG. 3 is a view taken in the direction of arrow A of the chip according to the first exemplary embodiment of the present invention.

FIG. 4 is a view in the direction of arrow B of the chip according to the first exemplary embodiment of the present invention.

FIG. 5 is an explanatory diagram showing the shape of serrations of the chip according to the first embodiment of the present invention.

FIG. 6A is a plan view of a throw-away type end mill in which a tip is mounted according to the first embodiment of the present invention,
(B) is a front view of the end mill.

FIG. 7 is a side view of the throw-away type ball end mill to which the tip according to the first embodiment of the present invention is attached.

FIG. 8 is an explanatory diagram showing a first modification of the serration of the chip according to the first embodiment of the present invention.

FIG. 9 is an explanatory diagram showing a second modification of the serration of the chip according to the first embodiment of the present invention.

FIG. 10 is a perspective view of a chip according to a second exemplary embodiment of the present invention.

FIG. 11 is a top view of a chip according to a second embodiment of the present invention.

FIG. 12 is a plan view of a throw-away type ball end mill equipped with a tip according to a second embodiment of the present invention.

[Explanation of symbols]

10 chips 11 Lower surface 12 Upper surface 12A inclined surface 14 Groove 14A Bottom of groove 15 Yamabe 15A Mountain top 16 serrations 17 cutting edge 17A, 17B corner 17C First inclined cutting edge 17D Second inclined cutting edge 20 Throwaway Ball End Mill Distance between the bottom of the groove and the top of the mountain p Distance between the vertices of the mountain X1, X2 intersection S1, S2 tangent α, β inclination angle

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hiroshi Shimomura             1511 Furumagi, Ishishita-cho, Yuki-gun, Ibaraki Prefecture             Mitsubishi Materials Corporation Tsukuba Works F term (reference) 3C022 KK02 KK06 KK12 KK23 KK25                       MM15                 3C046 CC06

Claims (10)

[Claims] 1. A substantially arcuate cutting edge is formed on a side edge portion of an upper surface facing a lower surface which is a seating surface, and when the cutting edge is mounted on a tool body, a rotation locus of the cutting edge is substantially spherical. A saw-away tip that forms a part of the above, wherein the upper surface is formed with serrations in which a plurality of groove portions and mountain portions are alternately arranged, and the cutting edge has a wavy shape. Throw away tip. 2. The throw-away tip according to claim 1, wherein the groove and the peak are formed by a curved surface. 3. The throw-away tip according to claim 1 or 2, wherein the groove portion and the crest portion are directed toward a tool body outer peripheral side according to a tool body tip side, or on a tool rotation axis. Extends in a direction perpendicular to the axis of rotation of the tool,
A throw-away tip, wherein the serration is formed so as to be inclined in the range of 90 ° to 90 °. 4. The throw-away tip according to any one of claims 1 to 3, when viewed in a cross section orthogonal to a direction in which the groove and the peak extend, the bottom of the groove and the peak are formed. The throw-away tip, wherein the distance in the thickness direction of the throw-away tip from the apex is set in the range of 0.3 mm to 1.2 mm. 5. The throw-away tip according to any one of claims 1 to 4, wherein when viewed in a cross section orthogonal to a direction in which the groove portion and the crest portion extend, a distance between apexes of the crest portion is increased. The distance is 2.0 mm to 10.
A throw-away tip that is set in the range of 0 mm. 6. The throw-away tip according to claim 1, wherein when viewed in a cross section orthogonal to a direction in which the groove and the crest extend, the groove and the crest are 2 A throw-away tip formed in a curved shape with a radius of curvature in the range of 0.0 mm to 10.0 mm. 7. The throw-away tip according to any one of claims 1 to 6, when viewed in a cross section orthogonal to a direction in which the groove portion and the crest portion extend, the crest portion and a tool body tip side thereof. The absolute value of the inclination angle formed by the tangent at the intersection with the groove adjacent to the lower surface with respect to the lower surface, and the tangent at the intersection between the ridge and the groove adjacent to the tool body rear end side is the lower surface. The throw-away tip is characterized in that the absolute value of the tilt angle made with respect to each other is different from each other. 8. The throw-away tip according to claim 7, wherein an absolute value of an inclination angle formed by a tangent line at an intersecting portion between the crest portion and the groove portion adjacent to the tip end side of the tool body with respect to the lower surface, A throw-away tip, wherein a tangent line at an intersection of the mountain portion and the groove portion adjacent to the rear end side of the tool body is larger than an absolute value of an inclination angle formed with respect to the lower surface. 9. The throw-away tip according to any one of claims 1 to 8, wherein the intersecting portion of the groove portion and the crest portion is formed by a flat surface. 10. The throw-away tip according to any one of claims 1 to 9, wherein the upper surface that is continuous with the tip portion of the cutting edge gradually approaches the lower surface as it goes toward the tip of the cutting edge. A throw-away tip, characterized in that the serration is formed on the upper surface excluding the inclined surface.