JP4048685B2 - Throwaway tip - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a throw-away tip (hereinafter sometimes referred to as a tip) suitable for being mounted on, for example, an end mill of a rolling tool for die processing.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, there is a type in which a throw-away tip is attached as a replaceable blade to an end mill, and a workpiece is processed by cutting a rotating end mill into a workpiece to a desired depth and feed-cutting.
The conventional throw-away tip shown in FIGS. 9 to 13 has a substantially rectangular plate shape, and one of the upper and lower surfaces facing in the thickness direction is a rake face 1 and the other is an attachment face 2 to the end mill body. Nose parts 4 and 4 whose cutting edges form arcuate shapes are formed at opposing corner parts 3 and 3 of the rake face 1 of the chip body, and a pair of opposing side surfaces 5 of the chip body adjacent to the nose parts 4 and 4. Main cutting edges 6 and 6 are formed on the intersecting ridge line formed by 5 and the rake face 1.
Here, the cutting blades of the pair of nose portions 4 and 4 facing the throw-away tip are parallel to the mounting surface 2. The cutting blades of the pair of nose portions 4 and 4 serve as a reference for the mounting surface 2 when the chip is inverted and mounted to polish the mounting surface 2 to obtain flatness.
Furthermore, the main cutting blades 6 and 6 are inclined blades that are linearly inclined so that the distance from the mounting surface 2 gradually decreases from the nose portions 4 and 4 to the other corner portions 8 and 8. Further, short straight cutting edges 9 and 9 are provided on the ridge line opposite to the main cutting edges 6 and 6 with the nose portions 4 and 4 interposed therebetween.
In such a throw-away tip, the nose portion 4 is positioned on the outer peripheral side of the tip, is attached to the end mill, the main cutting edge 6 is the outer peripheral cutting edge, and the auxiliary cutting edge 9 is the front cutting edge. . In these throwaway tips, the attachment surface 2 is inclined by a predetermined angle with respect to the rotation axis X of the end mill when viewed from the side, whereby the axial rake angle of the main cutting edge is greater than the inclination angle of the attachment surface 2. A large positive angle can be achieved, and the cutting resistance can be reduced.
[0003]
[Problems to be solved by the invention]
However, the conventional throw-away tip in which the cutting edge of the nose portion 4 is parallel to the mounting surface 2 has the following drawbacks.
When machining by shallow cutting into the work material, a portion to be cut with the inclined blade is reduced in the entire cutting, and the entire cutting is cut only with the cutting blade of the nose portion 4. However, since the cutting edge of the nose portion 4 is parallel to the mounting surface 2, if only the cutting edge of the nose portion 4 is cut, the axial rake angle becomes small and the sharpness deteriorates.
In order to improve the sharpness, in order to extend the inclined blade toward the nose portion 4, the radius of curvature of the cutting edge of the nose portion 4 must be reduced so that the nose portion 4 becomes smaller. However, it is difficult to reduce the curvature radius of the cutting edge in terms of production technology in the conventional manufacturing method in which a chip is manufactured by sintering metal powder.
[0004]
Also, when an end mill is sent in an oblique direction by die machining or the like and a complicated slope is three-dimensionally machined, since the trace of the arc-shaped cutting by the cutting edge of the nose portion 4 is left on the machining surface, the finished surface is rough. Become. In order to improve the surface finish, the radius of curvature of the nose portion 4 must be increased. Then, the cutting edge of the nose part 4 increases and the situation where only the cutting edge of the nose part 4 cuts only the whole incision arises. Therefore, there is the above-mentioned problem that the sharpness at the time of shallow cutting is poor.
[0005]
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a throw-away tip that reduces cutting resistance and improves sharpness without affecting the polishing of the mounting surface.
[0006]
[Means for Solving the Problems]
According to the first aspect of the present invention, a substantially polygonal plate shape is formed, and one surface facing the mounting surface to the tool body is a rake face, and the cutting edge has a substantially arc shape at a corner of the rake face. A slope where a nose portion is formed, and the distance from the mounting surface gradually decreases as the distance from the nose portion increases to one of two intersecting ridgelines formed by each of two adjacent side faces sandwiching the nose portion and the rake face In a throw-away tip in which a main cutting edge as a blade is formed and a secondary cutting edge for finishing a workpiece surface is formed on the other side, the cutting edge of the nose portion is substantially parallel to the mounting surface. The mounting surface is formed between a flat cutting blade portion, and the flat cutting blade portion and the main cutting blade, and the inclination of the cutting blade is the same as the inclination of the main cutting blade with respect to the mounting surface. And an inclined cutting edge part whose distance from the That.
[0007]
With such a configuration, the inclined cutting edge portion is provided without changing the curvature radius of the cutting edge of the nose portion. When performing shallow cutting such as cutting only with the cutting edge of the nose portion, cutting is performed with the inclined cutting edge portion, so that the cutting resistance is reduced and the sharpness is improved.
[0008]
The invention according to claim 2 is the throw-away tip according to claim 1, wherein the flat cutting edge portion passes through one end of the flat cutting edge portion and is a straight line perpendicular to the tangential direction of the flat cutting edge portion. The perpendicular cut from the other end of the flat cutting edge is formed to be 2 mm or longer.
[0009]
With such a configuration, the flat cutting edge portion supports the chip and serves as a reference for the mounting surface when the chip is inverted and mounted at the time of chip manufacturing and the mounting surface is polished to obtain flatness.
[0010]
A third aspect of the present invention is the throw-away tip according to the second aspect, wherein the nose portions are respectively formed at opposing corner portions of the rake face, and the flat cutting edge portions of the nose portions are arranged in the mounting direction. The distance from the surface is equal.
[0011]
By adopting such a configuration, when the chip is mounted in an inverted manner, the chip is supported by the flat cutting edge portion located at the opposite corner and becomes the reference surface for mounting surface polishing. Further, two cutting blades that can be used for replacement are provided on one chip body.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a throw-away tip according to an embodiment of the present invention will be described with reference to the drawings.
[0013]
The throw-away tip A shown in FIGS. 1 to 8 is made of, for example, cemented carbide and has a substantially polygonal plate shape, particularly a substantially rectangular plate shape, and a substantially parallelogram-shaped plate shape in the thickness direction. One of the upper and lower surfaces facing the rake face 10 is the rake face 10 and the other is the attachment face 20 to the tool body.
Nose portions 40, 40 having arcuate cutting edges are formed at the acute corner portions 30, 30 of the rake face 10 facing the diagonal direction of the parallelogram. The rake face 10 has inclined surfaces 11 and 11 whose distance from the mounting surface 20 gradually decreases from the outside toward the center, and the inclined surfaces 11 and 11 and the main portions adjacent to the nose portions 40 and 40 are disposed. Main cutting edges 60 and 60 are formed on a pair of parallel ridge lines formed by the side surfaces 50 and 50 which are flank surfaces. The main cutting blades 60 and 60 are inclined blades whose distance from the mounting surface 20 gradually decreases as the distance from the nose portions 40 and 40 increases.
Further, the other side surfaces 70 and 70 adjacent to the nose portions 40 and 40 are sub-flank surfaces. A side surface 72 of the nose portion 40 between the side surface 50 and the side surface 70 has a cylindrical circumferential shape, and planes 71 and 71 are formed between the side surface 72 and the side surface 70 of the nose portion 40. . The intersecting ridge line formed by the flat surfaces 71 and 71 and the rake face 10 is the sub cutting edges 80 and 80 for finishing the surface of the work material, and the angle formed with the main cutting edges 60 and 60 in a plan view is substantially perpendicular. It is provided to be.
Here, each of the side surfaces 50, 70, 72 and the flat surface 71 has a positive clearance angle inclined outward from the mounting surface 20 toward the rake surface 10.
Further, in the center of the chip body 100, a boss 12 is provided on the rake face 10 side, and a screw insertion hole 90 is formed through the rake face 10 and the attachment face 20.
[0014]
The cutting edges of the nose portions 40, 40 are each formed between a flat cutting edge portion 41 parallel to the mounting surface 20, an end portion P of the flat cutting edge portion 41, and an end portion Q of the main cutting edge 60, and The inclination of the cutting edge includes, for example, an inclined cutting edge portion 42 that is the same as the inclination of the main cutting edge 60 with respect to the mounting surface 20.
The length of the perpendicular L drawn from the other end P of the flat cutting edge 41 to an imaginary straight line passing through one end R of the flat cutting edge 41 and perpendicular to the tangential direction of the flat cutting edge 41 at the one end R. The cutting edge of the flat cutting edge portion 41 is formed so that the length is 2 mm or more.
[0015]
In the throw-away tip A having such a configuration, the nose portion 40 is positioned on the outer peripheral side of the tip, the main cutting edge 60 is the outer peripheral cutting edge, and the auxiliary cutting edge 80 is mounted on the end mill 200. It is a front blade, the mounting surface 20 is brought into contact with the mounting seat, and is screwed to a location indicated by M in the drawing. At this time, the throw-away tip A has an axial rake angle of a positive angle α with respect to the rotation axis X of the end mill 200 when the main cutting edge 60 is viewed from the side in order to reduce cutting resistance during cutting and improve sharpness. Inclined to have.
[0016]
In the throw-away tip A shown in FIGS. 1 to 8, the inclined cutting blade portions 42 and 42 are provided without changing the curvature radius of the cutting blades of the nose portions 40 and 40. When performing shallow cutting such as cutting exclusively, since the cutting is performed by the inclined cutting edge portions 42 and 42, a positive axial rake angle α larger than the tip mounting posture is obtained, and the cutting resistance is reduced. Sharpness is improved.
[0017]
In addition, a plane including the cutting edge of the flat cutting edge portion 41 is uniquely determined within the allowable error range, and the mounting surface 20 with this plane as a reference is uniquely determined. Therefore, when the chip body 100 is inverted and mounted when the chip body 100 is manufactured, and the mounting surface 20 is polished to obtain flatness, the flat cutting blade portions 41 and 41 support the chip body 100 and the mounting surface 20. Become a standard. In practice, the flat cutting edge portions 41 and 41 are brought into contact with a jig serving as a reference surface, and the mounting surface 20 side is polished so that the distance from the reference surface is constant.
[0018]
According to the throw-away tip A shown in FIGS. 1 to 8, the inclined cutting edge 42 is provided by securing the length of the flat cutting edge 41 serving as a reference for polishing the mounting surface 20, and the inclined blade is provided on the outer periphery of the tip. Can be extended towards. Therefore, also when processing by shallow cutting into a work material, cutting resistance can be made small and sharpness can be improved.
Alternatively, when the radius of curvature of the cutting edge of the nose portion 40 is increased for slope cutting, the inclined cutting edge portion 42 is extended while the length of the flat cutting edge portion 41 is kept constant, whereby the cutting edge of the inclined blade is cut. You can keep the length. Therefore, sharpness can be maintained.
Thus, by providing the flat cutting edge part 41 and the inclined cutting edge part 42 in the nose part 40, the cutting resistance at the time of shallow cutting is reduced to improve the sharpness, and without reducing the sharpness, The radius of curvature of the nose portion 40 can be increased for the surface finishing of the slope processing.
[0019]
Further, the mounting surface 20 can be polished so that the flat thickness of the chip main body 100 can be realized by bringing the opposed flat cutting edge portions 41 and 41 into contact with the reference surface.
[0020]
Since the chip body 100 is formed point-symmetrically with respect to the center, the corner can be changed.
[0021]
In addition, the inclination angle with respect to the mounting surface 20 of the inclined cutting edge portion 42 may not be the same as that of the main cutting edge 60 and can be set as appropriate. Moreover, the inclined cutting edge part 42 and the main cutting edge 60 do not necessarily need to be linear, and may be curved such as a convex curve or a concave curve.
[0022]
【The invention's effect】
As described above, the throw-away tip according to the present invention can improve the sharpness by securing the polishing accuracy of the mounting surface in the nose portion and reducing the cutting resistance when performing shallow cutting.
In addition, the sharpness can be maintained even when the radius of curvature of the nose portion is increased in order to improve the surface finish of the slope processing.
[0023]
Further, according to the present invention, it is possible to polish the mounting surface so that the flat cutting edge portions provided at the opposite corner portions are brought into contact with the reference surface and the accurate thickness of the chip body can be realized.
[0024]
In addition, according to the present invention, when the one nose portion, the main cutting edge, or the auxiliary cutting edge is worn due to a machining operation, the tip body can be immediately replaced with the other blade.
[Brief description of the drawings]
FIG. 1 is a perspective view of a throw-away tip according to an embodiment of the present invention.
FIG. 2 is a plan view of a throw-away tip according to an embodiment of the present invention.
FIG. 3 is a front view of the throw-away tip according to the embodiment of the present invention.
FIG. 4 is a left side view of the throw-away tip according to the embodiment of the present invention.
FIG. 5 is a plan view showing a state in which the throw-away tip according to the embodiment of the present invention is attached to the end mill.
FIG. 6 is a front view showing a state in which the throw-away tip according to the embodiment of the present invention is attached to the end mill.
FIG. 7 is a right side view showing a state in which the throw-away tip according to the embodiment of the present invention is attached to the end mill.
FIG. 8 is a diagram further enlarging a portion O in FIG. 7;
FIG. 9 is a perspective view of a conventional throw-away tip.
FIG. 10 is a plan view of a conventional throw-away tip.
FIG. 11 is a front view of a conventional throw-away tip.
FIG. 12 is a left side view of a conventional throw-away tip.
FIG. 13 is a view showing a state in which a conventional throw-away tip is mounted on an end mill.
[Explanation of symbols]
A ... throw-away tip 10 ... rake face 11 ... inclined surface 20 ... mounting surface 30 ... corner 40 ... nose 41 ... flat cutting edge 42 ... inclined Cutting edge portion 50 ... side surface 60 ... main cutting edge 100 ... chip body

Claims (3)

It has a substantially polygonal plate shape, and one surface facing the mounting surface to the tool body is a rake surface, and a nose portion in which the cutting edge forms a substantially arc shape is formed at the corner portion of this rake surface. A main cutting edge formed as an inclined blade whose distance from the mounting surface gradually decreases as the distance from the nose portion increases in one of two intersecting ridgelines formed by each of two adjacent side faces sandwiching the rake face. On the other hand, in the throw-away tip on which the secondary cutting edge for finishing the workpiece surface is formed ,
The cutting blade of the nose portion is formed between a flat cutting blade portion that is substantially parallel to the mounting surface, and the flat cutting blade portion and the main cutting blade, and the inclination of the cutting blade is the main cutting blade. A throw-away tip having an inclined cutting edge portion whose distance from the attachment surface gradually changes so as to be the same as the inclination of the attachment surface to the attachment surface . 2. The throwaway tip according to claim 1, wherein the flat cutting blade portion passes through one end of the flat cutting blade portion, and at one end of the flat cutting blade to a virtual straight line perpendicular to a tangential direction of the flat cutting blade portion. A throw-away tip formed so that the length of a perpendicular drawn from the other end of the portion is 2 mm or more. The throw-away tip according to claim 1 or 2, wherein the nose portions are respectively formed at opposing corner portions of the rake face, and the flat cutting edge portions of these nose portions have the same distance from the mounting surface. A throw-away chip featuring

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