JP2021146425A - Cutting insert with chip breaker - Google Patents

Abstract

To fragment chips by restraining them against a flank by guiding the chips so as to surely curl toward the flank side when narrow and thin chips are generated.SOLUTION: A rake face 5 is formed on at least one end face 2 of a plate-shaped insert body 1 having two end faces 2 and a side face, and a flat seating face 8 is formed on the other end face 2. A cutting edge 6 having a side face as a flank is formed at an intersection ridge line part between the rake face 5 and the side face. On the rake face 5, a chip breaker 7A protruding from the rake face 5 is formed on the inner side of the cutting edge 6. A breaker wall face 7c facing the cutting edge 6 side of the chip breaker 7A extends in a direction perpendicular to a reference plane P parallel to the seating face 8 or a direction of inclining toward the cutting edge 6 side as the chip breaker protrudes from the rake face 5.SELECTED DRAWING: Figure 6

Description

In the present invention, a rake face is formed on at least one end surface of the plate-shaped insert body, and a flat seating surface is formed on the other end face, and the intersecting ridge line between the rake face and the side surface of the insert body is formed. It relates to a cutting insert with a tip breaker in which a cutting edge having this side surface as a flank is formed in a portion thereof, and a tip breaker protruding from the rake face is formed on the inside of the cutting edge on the rake face. be.

As such a cutting insert with a tip breaker, for example, in Patent Document 1, the upper surface of the insert body having a polygonal flat plate shape is a rake face, and cutting edges are formed on the ridges of the rake face and the cutting edges are formed on each other. A nose cutting edge is formed at the nose portion where the adjacent cutting edges intersect with each other, and a tip breaker protruding from the rake face is formed on the rake face so as to extend toward the nose portion. Cutting inserts with tip breakers are listed.

In the cutting insert with a tip breaker described in Patent Document 1, the rake angle of the nose portion cutting edge gradually increases from both ends of the nose portion cutting edge toward the position on the bisector of the nose portion. Of the breaker wall surface of the chip breaker, the portion facing the cutting edge of the nose portion has a first breaker wall surface that rises from the rake surface and a first breaker wall surface from the first breaker wall surface. A second breaker wall surface that rises more gently than the breaker wall surface of the above is formed.

Japanese Unexamined Patent Publication No. 11-197912

By the way, in such a cutting insert with a chip breaker, especially when a narrow and thin chip is generated by the cutting edge around the nose cutting edge (corner blade), resistance is given to the chip by the breaker wall surface. It is divided by guiding it to curl toward the flank and restraining it by applying chips to the flank.

However, even in the cutting insert with a chip breaker described in Patent Document 1 and other general cutting inserts with a chip breaker, the breaker wall surface facing the cutting edge side of the chip breaker protrudes from the cutting edge as it protrudes from the rake face. It curls by inclining in the direction away and giving resistance to the chips.

For this reason, especially when cutting a work material made of a relatively soft material with a cutting edge around the corner blade, the chips tend to extend and get over the chip breaker, and as described above, the chips It was difficult to divide the blade by guiding it to curl toward the flank and restraining it by hitting it against the flank.

The present invention has been made under such a background, and when a cutting process is performed so as to generate narrow and thin chips on a work material made of a relatively soft material, such chips are used. It is an object of the present invention to provide a cutting insert with a tip breaker which can be divided by hitting the flank surface and restraining the cutting insert by guiding the cutting tool so as to surely curl it toward the flank surface side.

In order to solve the above problems and achieve such an object, the present invention presents at least one plate-shaped insert body having two end faces and sides arranged around these end faces. A rake face is formed on the end face, and a flat seating surface is formed on the other end face, and a cutting edge having the side surface as an escape surface is formed at an intersecting ridge between the rake face and the side surface. A cutting insert with a chip breaker in which a chip breaker protruding from the rake surface is formed on the rake surface, and the wall surface of the breaker facing the cutting edge side of the chip breaker. Is characterized in that it extends in a direction perpendicular to the reference plane parallel to the seating surface, or in a direction in which it is inclined toward the cutting edge side as it protrudes from the rake face.

In the cutting insert with a chip breaker configured as described above, Patent Document 1 describes that the breaker wall surface facing the cutting edge side of the chip breaker extends in a direction in which it is inclined away from the cutting edge as it protrudes from the rake face. Contrary to a cutting insert with a tip breaker or a general cutting insert with a tip breaker, the direction is perpendicular to the reference plane parallel to the seating surface, or toward the cutting edge side as it protrudes from the rake face. It extends in the direction of inclination.

For this reason, the chips generated by the cutting edge and flowing out from the rake face to the inside of the cutting edge are directed to the cutting edge side in the outflow direction by being applied to the wall surface of the breaker, and curl over the cutting edge to the flank side. Will be forced. Then, the chips curled toward the flank surface side are separated by hitting the flank surface and being restrained, so that narrow and thin chips are generated with respect to the work material made of a relatively soft material. It is possible to reliably cut chips even when performing various cutting processes.

Here, when the breaker wall surface extends in a direction in which it is inclined toward the cutting edge side as it protrudes from the rake face with respect to the reference plane parallel to the seating surface, the cross section perpendicular to the cutting edge. In the above, it is desirable that the breaker wall surface extends in a direction of inclining at an angle of 45 ° or more with respect to the reference plane.

That is, if this angle is small enough to be less than 45 °, when the chips flowing from the rake face to the inside of the cutting edge are applied to the breaker wall surface, the outflow direction is suddenly changed to the cutting edge side by the breaker wall surface. As a result, the breaker wall surface and the rake surface may be separated to cause chip clogging.

Further, since narrow and thin chips are generated mainly by cutting around the corner blade of the cutting blade, at least one end face thereof is formed into a polygonal surface shape. When the cutting edge is provided with a corner blade at a corner of the polygonal surface, it is desirable that the chip breaker is formed inside the corner blade, and thus by the periphery of the corner blade. The narrow and thin chips generated can be reliably processed by a chip breaker provided with a breaker wall surface as described above.

As described above, according to the present invention, even when a cutting process is performed in which narrow and thin chips are generated on a work material made of a relatively soft material, such chips are surely escaped. By guiding it to curl toward the surface side, it is possible to divide and process it by applying it to the flank and restraining it.

It is a perspective view which shows one Embodiment of this invention. It is a cross-sectional perspective view along the diagonal line of the acute angle portion in the two end faces (diamond faces) of the embodiment shown in FIG. FIG. 5 is a plan view of the embodiment shown in FIG. 1 as viewed from a direction facing one end face. It is a side view of the arrow line V direction view in FIG. It is a side view of the arrow line W direction view in FIG. FIG. 3 is a cross-sectional view taken along the line XX in FIG. It is a cross-sectional view of YY in FIG. FIG. 3 is a cross-sectional view taken along the line ZZ in FIG. It is a perspective view which shows the modification of the embodiment shown in FIG.

1 to 9 show an embodiment of the present invention. In the present embodiment, the insert body 1 is formed of a hard material such as cemented carbide in a plate shape having two end faces 2 and side surfaces 3 arranged around the end faces 2. The end face 2 is formed in a polygonal plane shape in the present embodiment, particularly in a rhombic plane shape, and therefore the insert body 1 includes the four side surfaces 3 described above.

The two end faces 2 of the insert body 1 are opened with mounting holes 4 having a circular cross section centered on the insert center line C passing through the center of the rhombus formed by the end faces 2. The insert body 1 has a 180 ° rotationally symmetric shape around the insert center line C, and is also formed in an inverted symmetric shape with respect to the two end faces 2 on the front and back sides.

A rake face 5 is formed on the outer peripheral edge portion of the end surface 2, and a cutting edge 6 having the side surface 3 as an escape surface is formed on the intersecting ridge line portion between the rake face 5 and the side surface 3. The rake face 5 is formed so as to gradually recede in the insert center line C direction toward the inside of the end face 2 away from the cutting edge 6 and then extend perpendicularly to the insert center line C. Further, the side surface 3 which is the flank surface of the cutting edge 6 extends parallel to the insert center line C, and the cutting insert with a tip breaker of the present embodiment is a negative type cutting insert with a tip breaker.

Further, the cutting edge 6 has a corner blade 6a having a convex curved shape such as a convex arc when viewed from the direction facing the end surface 2 in the insert center line C direction at each of the four corners of the rhombic surface formed by each end surface 2. I have. The cutting edge 6 of the portion other than the corner blade 6a is formed in a straight line in contact with the corner blade 6a at both ends of the corner blade 6a, and the cutting edge 6 including the corner blade 6a has an insert center line at each end surface 2. It extends on one plane perpendicular to C.

Further, on the rake face 5, a tip breaker protruding from the rake face 5 in the direction of the insert center line C is formed inside the cutting edge 6. In the present embodiment, the first chip breaker 7A is formed inside each of the four corner blades 6a for one end surface 2, and the cutting blade 6 extending linearly between the corner blades 6a adjacent in the circumferential direction. Two second chip breakers 7B are formed near the central portion, and a third chip breaker 7C is formed inside the first and second chip breakers 7A and 7B.

Of these, the third chip breaker 7C protrudes in the insert center line C direction from the cutting edge 6 and the first and second chip breakers 7A and 7B at each end surface 2 as shown in FIGS. 5 and 6. It is formed like this. The tip surface of the third chip breaker 7C is a flat boss surface 8 that is perpendicular to the insert center line C and surrounds the opening of the mounting hole 4, and the boss surface 8 is a cut of one end surface 2. When the blade 6 is used for cutting, the boss surface 8 of the other end surface 2 is a seating surface that is seated on the bottom surface of the insert mounting seat formed on the cutting tool with a replaceable cutting edge.

Further, the first and second chip breakers 7A and 7B are formed so that their tip surface 7a protrudes in a convex curved surface shape such as a convex spherical surface, and the second chip breaker 7B has such a convex curved surface. It is formed so as to protrude from the rake face 5. The tip surface 7a of the first chip breaker 7A has a larger protrusion height in the insert center line C direction than the tip surface 7a of the second chip breaker 7B.

Further, the third chip breaker 7C protrudes in the insert center line C direction toward the boss surface 8 side away from one cutting blade 6 extending between two corner blades 6a adjacent to each other in the circumferential direction. It is provided with an inclined breaker wall surface 7b. The breaker wall surface 7b of the third chip breaker 7C extends so as to protrude from the rake face 5 between the first and second chip breakers 7A and 7B and between the two second chip breakers 7B, and the second chip breaker 7B. The portion of the chip breaker 7B of the above is formed so as to project from the tip surface 7a of the second chip breaker 7B.

Then, in the present embodiment, as shown in FIGS. 6 to 8, the first chip breaker 7A formed inside the corner blade 6a is inclined toward the cutting blade 6 side as it protrudes from the rake face 5. A breaker wall surface 7c extending in the direction is formed between the tip surface 7a and the rake surface 5. The corner portion where the breaker wall surface 7c and the rake face 5 intersect has a concave curved shape in contact with the breaker wall surface 7c and the rake face 5 or a breaker wall surface in a cross section perpendicular to the cutting blade 6 (corner blade 6a). It may be formed in a straight line intersecting the 7c and the rake face 5.

In the present embodiment, the breaker wall surface 7c in the first chip breaker 7A has a boss surface 8 as a seating surface as shown in FIGS. 6 and 8 in a cross section perpendicular to the cutting blade 6 (corner blade 6a). As it protrudes from the rake face 5 at a constant angle θ with respect to the reference plane P parallel to, it extends in a direction of inclination toward the cutting edge 6 side, and this angle θ is set to 45 ° or more.

Here, a breaker wall surface 7c extending in an inclined direction toward the cutting edge 6 side as it protrudes from the rake surface 5 is formed between the tip surface 7a of the first chip breaker 7A and the rake surface 5. For example, a convex curved chip breaker similar to the second chip breaker 7B may be formed, and grinding or electric discharge machining may be performed on the rake face 5 side of the surface facing the cutting edge 6 side.

In the cutting insert with a chip breaker configured in this way, the breaker wall surface 7c of the first chip breaker 7A is a rake surface 5 with respect to the reference plane P parallel to the boss surface 8 as the seating surface as described above. As it protrudes from the cutting edge, it extends in a direction of inclination toward the cutting edge 6. Therefore, the chips generated by the cutting edge 6 and flowing out from the rake face 5 to the inside of the cutting edge 6 are applied to the breaker wall surface 7c so that the outflow direction is directed to the cutting edge 6 side.

Then, the chips whose outflow direction is directed to the cutting edge 6 side in this way get over the cutting edge 6 and are curled toward the side surface 3 side which is an escape surface, and are separated by hitting the side surface 3 and being restrained. Therefore, even when a work material made of a relatively soft material is cut so that narrow and thin chips are generated around the corner blade 6a of the cutting blade 6, the chips can be reliably processed. It will be possible.

Here, as described above, the breaker wall surface 7c of the first chip breaker 7A is inclined toward the cutting edge 6 side as it protrudes from the rake face 5 with respect to the reference plane P parallel to the boss surface 8 serving as the seating surface. In the cross section perpendicular to the cutting edge 6 (corner blade 6a), the breaker wall surface 7c is inclined at an angle θ of 45 ° or more with respect to the reference plane P as in the present embodiment. It is desirable that it is extended.

That is, when this angle θ is so small that it is smaller than 45 °, when the chips flowing from the rake face 5 to the inside of the cutting edge 6 are applied to the breaker wall surface 7c, the outflow direction is suddenly changed to the cutting edge side by the breaker wall surface 7c. There is a risk that the chips will be separated between the breaker wall surface 7c and the rake face 5 and the chips will be clogged.

When the curl size of the chips whose outflow direction is changed differs depending on the hardness of the work material or the like, the breaker wall surface 7c is formed in a convex curve shape or a concave curve shape in the cross section perpendicular to the cutting edge 6. In that case, the angle θ may be, for example, an angle with respect to the reference plane P of the tangent line of the breaker wall surface 7c at the intersection with the tip surface 7a of the first chip breaker 7A.

Further, the angle θ may be 90 °, that is, the breaker wall surface 7c may extend in a direction perpendicular to the reference wall surface P parallel to the boss surface 8 serving as the seating surface. Also in this case, the breaker wall surface 7c is inclined in the direction away from the cutting edge 6 as it protrudes from the rake face 5 like the cutting insert with a chip breaker described in Patent Document 1 and the cutting insert with a general chip breaker. Since it does not extend in the direction, it is possible to reliably process the chips in the outflow direction toward the cutting edge 6.

Further, since chips that are narrow and thin and tend to be stretched are often cut by using the periphery of the corner blade 6a of the cutting blade 6, the insert body 1 is used as in the present embodiment. When the end surface 2 is formed in a polygonal plane shape and the cutting edge 6 is provided with a corner blade 6a at a corner of the polygonal surface, the breaker wall surface 7c is parallel to the boss surface 8 serving as a seating surface. The first tip breaker 7A extending in a direction perpendicular to the reference plane P or in a direction inclined toward the cutting edge 6 side as it protrudes from the rake face 5 is formed inside the corner blade 6a. It is desirable to have.

However, such a breaker wall surface 7c may be provided in the second chip breaker 7B or the third chip breaker 7C. Further, in the present embodiment, the case where the present invention is applied to a cutting insert with a chip breaker having a diamond-shaped plate-shaped insert body 1 has been described. It is also possible to apply the present invention to cutting inserts, and it is also possible to apply the present invention to other polygonal plate-shaped or disc-shaped cutting inserts.

1 Insert body 2 End face of insert body 1 3 Side surface of insert body 1 (escape surface)
4 Mounting hole 5 Scoop surface 6 Cutting blade 6a Corner blade 7A-7C 1st to 3rd chip breakers 7a Tip surface of 1st and 2nd chip breakers 7b Breaker wall surface of 3rd chip breaker 7C 7c 1st chip Breaker 7A Breaker wall surface 8 Boss surface (seating surface)
P Reference plane parallel to the boss surface 8 (seat surface) θ Angle of the breaker wall surface 7c with respect to the reference plane P in the cross section perpendicular to the cutting blade 6 (corner blade 6a)

Claims (3)

A rake face is formed on at least one of the end faces of a plate-shaped insert body having two end faces and a side surface arranged around these end faces, and a flat seat is formed on the other end face. The surface is formed,
A cutting edge having the side surface as a flank is formed at the intersection ridgeline portion between the rake surface and the side surface, and at the same time.
A cutting insert with a tip breaker in which a tip breaker protruding from the rake face is formed on the rake surface inside the cutting edge.
The breaker wall surface of the chip breaker facing the cutting edge side extends in a direction perpendicular to the reference plane parallel to the seating surface, or in a direction inclined toward the cutting edge side as it protrudes from the rake surface. A cutting insert with a tip breaker that is characterized by being The cutting insert with a tip breaker according to claim 1, wherein the breaker wall surface extends in a direction inclined at an angle of 45 ° or more with respect to the reference plane in a cross section perpendicular to the cutting edge. The at least one end face is formed in a polygonal plane shape, and the cutting edge is provided with a corner blade at a corner of the polygonal face.
The cutting insert with a tip breaker according to claim 1 or 2, wherein the tip breaker is formed inside the corner blade.

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