JP6852258B2 - Cutting inserts and cutting tools with replaceable cutting edges - Google Patents

Description

The present invention relates to a cutting insert that is detachably attached to an insert mounting seat formed on a tool body of a cutting tool with a replaceable cutting edge, and a cutting tool with a replaceable cutting edge to which the cutting insert is detachably attached.

As a cutting insert unsintered body that can be sintered into such a cutting insert, for example, in Patent Document 1, two main edge portions and sub-side surfaces formed by an intersection of a main side surface and upper and lower end surfaces are provided. Described are those with two sub-edges formed by the intersections of the upper and lower end faces and four corner edges formed by the intersections of the corner faces with each of the upper and lower end faces. ing. Such a cutting insert unsintered body is formed by compacting a sintered powder with a tool set (press molding die) equipped with a die and a punch, and a main cutting edge is formed on the main edge portion. A secondary cutting edge is sintered on the secondary edge, and a double-sided cutting insert having a corner edge formed on the corner edge is sintered.

Japanese Patent Application Laid-Open No. 2008-528306

By the way, when such a cutting insert is attached to an insert mounting seat formed on the outer periphery of the tip of a tool body that is rotated around an axis, and the work material is shoulder-cut to form a recess, the above-mentioned The main cutting edge forms the wall surface of the recess, the sub cutting edge forms the bottom surface of the recess, and the corner blade forms the corner portion where these wall surfaces and the bottom surface intersect. However, it may be required to form corners having various radii.

To meet such requirements, it is necessary to prepare a plurality of types of cutting inserts with different radii of the corner cutting edge corresponding to the radius of the corner and allowed to sinter to the plurality of types of cutting inserts It is inefficient and uneconomical to prepare a dedicated press-molding die for each unsintered cutting insert. Therefore, in such a case, a press-molded die for a cutting insert having the smallest corner blade radius is prepared, and after sintering the unsintered cutting insert molded by this press-molded die, By polishing the flanks connected to the corner blades, the main cutting blade, and the sub cutting blades while maintaining the clearance angle, a plurality of types of cutting inserts having corner blades having a desired radius are manufactured.

However, in the case of manufacturing a plurality of types of cutting inserts in this way, if the rake face connected to the corner blade, the main cutting blade, and the sub cutting blade has a concave curved surface shape or, conversely, a convex curved surface shape, the corner When the flank is polished, the rake angle and blade angle of these cutting edges may change depending on the amount of polishing. If the rake angle or blade angle of the cutting edge changes in this way, the cutting performance will also differ.Therefore, it will be necessary to perform machining under different cutting conditions for each corner blade radius, or the life of the cutting insert. Will be different, which will complicate management. Further, especially when the rake face connected to the main cutting edge and the sub cutting edge is concave in a V shape through the rake face connected to the corner blade, the chips generated by these cutting blades interfere with each other and the chips are discharged. The sex may be impaired.

The present invention has been made under such a background, and even when a plurality of types of cutting inserts having different corner blade radii are manufactured by polishing the flank surface as described above, the cutting inserts are among the cutting inserts. It is an object of the present invention to provide a cutting insert capable of suppressing a change in cutting performance and having excellent chip evacuation property, and a cutting tool with a replaceable cutting edge to which such a cutting insert is detachably attached.

In order to solve the above problems and achieve such an object, the cutting insert of the present invention has two quadrangular faces facing each other and four side surfaces arranged around these quadrangular faces. The insert body is provided, and corner blades are formed at one of the two corner portions located on one diagonal line of the quadrangular surface, and two side edges of the quadrangular surface connected to the corner portion are formed. A main cutting edge and a sub cutting edge are formed in the portion, respectively, and on the quadrangular surface, a first corner rake surface connected to the corner blade, a first main rake surface connected to the main cutting edge, and the sub cutting surface are formed. The first sub-rake face connected to the blade is formed, and the first corner rake face and the portion of the first main rake face and the first sub rake face connected to the first corner rake face are one of the above. The secondary cutting edge is arranged on one inclined plane that inclines diagonally toward the inside of the quadrangular surface and toward the opposite quadrangular surface side, and the secondary cutting edge is a linear first line connected to the corner blade. A sub-cutting blade and a second sub-cutting blade connected to the side opposite to the corner blade of the first sub-cutting blade are provided, and these first and second sub-cutting blades are viewed from a direction facing the quadrangular surface. Sometimes intersecting at a blunt angle, the second secondary cutting edge is connected to the main cutting edge extending from the one corner portion on the other corner portion side of the quadrangular surface, and the rake surface is covered with the above. It is connected to the inner peripheral side of the first corner rake face, the first main rake face, and the first sub rake face, and is steeper than the first corner rake face, the first main rake face, and the first sub rake face. A second corner rake face, a second main rake face, and a second sub rake face that incline toward the opposite quadrangular surface side toward the inner peripheral side of the quadrangular surface are formed, and the first corner rake surface and the first first corner surface are formed. The intersecting ridge line of the main rake face, the first sub rake face, the second corner rake face, the second main rake face, and the second sub rake face is one of the above when viewed from the direction facing the quadrangular surface. The corner portion side of the quadrangle is convex, and the radius of the intersecting ridge line forming the convex curve is larger than the radius of the corner blade when viewed from the direction facing the quadrangular surface. It is characterized by that.
Further, the cutting insert of the present invention has an insert body having two quadrangular surfaces facing each other and four side surfaces arranged around these quadrangular surfaces, and is on one diagonal of the quadrangular surface. A corner blade is formed at one of the two corner portions located at, and a main cutting blade and a secondary cutting blade are formed at each of the two quadrangular edges connected to the corner portion. The quadrangular surface is formed with a first corner rake surface connected to the corner blade, a first main rake surface connected to the main cutting blade, and a first secondary rake surface connected to the sub cutting blade. The corner rake face and the portion of the first main rake face and the first sub rake face that are connected to the first corner rake face are opposite to each other in the diagonal direction toward the inside of the quadrangle face. The sub-cutting blades are arranged on one inclined plane that is inclined toward, and the sub-cutting blades are a linear first sub-cutting blade connected to the corner blade and the corner blade of the first sub-cutting blade. Is provided with a second secondary cutting edge connected to the opposite side, and these first and second secondary cutting edges intersect at an blunt angle when viewed from a direction facing the quadrangular surface, and the second secondary cutting edge is , The other corner portion side of the quadrangular surface is connected to the main cutting edge extending from the one corner portion, and in the insert body, the distance between the two quadrangular surfaces is the edge portion of the quadrangular surface. Among these, it is characterized in that it is a vertical blade type insert body having a length larger than the length of the side ridge portion on which the secondary cutting edge is formed.

Further, in the blade tip exchange type cutting tool of the present invention, an insert mounting seat is formed on the outer periphery of the tip portion of the tool body that is rotated around the axis, and the cutting insert having the above configuration has one of the above square surfaces on the insert mounting seat. The corner blade formed on one corner portion of the one square surface is projected toward the outer peripheral side of the tip of the tool body in the tool rotation direction, and the main cutting blade connected to the corner blade is used as the tool. It is characterized in that the auxiliary cutting blade connected to the corner blade is projected to the outer peripheral side of the main body and is detachably attached to the tip side of the tool main body.

The cutting insert of the above configuration, the first corner rake face continuous with the corner cutting edge, a first main rake face and a first portion continuing to the corner rake face of the first sub rake face continuous with the minor cutting edge connecting to the main cutting edge The insert body is arranged on one inclined plane that inclines toward the inside of the quadrangular surface in the diagonal direction of the quadrangular surface and toward the quadrangular surface opposite to the quadrangular surface. If the flanks of the corner blade, main cutting blade, and secondary cutting blade are polished while maintaining the clearance angle, the rake angle and blade angle of these corner blades, main cutting blade, and secondary cutting blade will change. There is no.

Therefore, it is possible to suppress the change in cutting performance depending on the radius of the corner blade, it is not necessary to change the machining conditions for each radius, and it is possible to prevent the management of the cutting insert from becoming complicated. Further, the portion communicating with the first corner rake face of the first main rake face and the first sub rake face is on the same inclined plane, chips generated at the portion connected to the corner cutting edge of the major cutting edge and minor cutting blade There is no interference, and it is possible to improve the chip evacuation property.

Further, in the present invention, in the above-mentioned blade tip exchange type cutting tool, a case where the tool body is rotated around the axis and is fed in the lateral direction intersecting the axis while being slightly fed in the axial direction to perform so-called ramping. for, in the minor cutting edge, provided with a first minor cutting edge straight connecting to the corner edge, and the first second sub cutting edge connected to opposite to the corner edge of the auxiliary cutting edge these first, second minor cutting edge intersect at an obtuse angle when viewed from a direction opposite to the square surface.

That is, when such a second secondary cutting edge is formed, if the flanks of the first and second secondary cutting edges are the same, the first secondary cutting edge is given a clearance angle to the second secondary cutting edge. The rake angle of the main cutting edge may become small and the sharpness may be impaired, or the machined surface may be easily dented on the side opposite to the corner blade of the first secondary cutting edge. However, by forming the first and second secondary cutting edges so as to intersect at an obtuse angle when viewed from the direction facing the quadrangular surface, the flanks connected to the first and second secondary cutting edges also have an obtuse angle. Since they intersect, the second secondary cutting edge and its flank can be separated from the machined surface formed by the first secondary cutting edge, and the rake angle of the first secondary cutting edge and the main cutting edge can be increased accordingly. It can be set to ensure sharpness, reduce cutting resistance, and prevent the occurrence of shavings.

Further, the first main rake face, the first sub rake face, and the first corner rake face located on the inclined plane as described above are placed on each of the two corner portions of the two quadrangular faces of one insert body. per the formed so as to be inclined toward the square surface of the opposite side, in the present invention, in order to ensure the strength of the insert body, the insert body, the distance between the two rectangles surface, the square insert body der of the auxiliary cutting edge is larger vertical blade type than the length of the Henryo portion formed of Henryo portion of the surface Ru.

As described above, according to the present invention, even if cutting inserts having different corner blade radii are manufactured by polishing, it is possible to suppress the change in cutting performance, and it is necessary to change the machining conditions. It is possible to obtain excellent chip evacuation by preventing the interference of chips without causing the insertion life management to become complicated.

It is a 1st perspective view which shows one Embodiment of the cutting insert of this invention. It is a second perspective view of the embodiment shown in FIG. FIG. 3 is a third perspective view of the embodiment shown in FIG. It is a fourth perspective view of the embodiment shown in FIG. FIG. 5 is a front view of the embodiment shown in FIG. 1 as viewed from a direction facing a quadrangular surface. FIG. 5 is a side view of the embodiment shown in FIG. 1 as viewed from a direction facing the first side surface. FIG. 5 is a plan view of the embodiment shown in FIG. 1 as viewed from a direction facing the second side surface. It is a perspective view of the tip part of one Embodiment of the cutting edge exchange type cutting tool of this invention which attached the cutting insert of the embodiment shown in FIG.

1 to 7 show an embodiment of a cutting insert of the present invention, and FIG. 8 shows an embodiment of a cutting tool with a replaceable cutting edge of the present invention to which the cutting insert of this embodiment is detachably attached. Is shown. The insert body 1 of the cutting insert of the present embodiment is formed in a quadrangular plate shape by a hard material such as cemented carbide. Such an insert body 1 is manufactured by sintering a molded body obtained by compacting a raw material powder such as cemented carbide with a press molding die, as described in Patent Document 1.

The insert body 1 includes two quadrangular surfaces 2 with their backs facing each other, and two first side surfaces 3 and two second side surfaces 4 arranged around the quadrangular surfaces 2. A mounting hole 5 penetrating the insert body 1 is formed in the center of the first side surface 3, and the insert body 1 has a 180 ° rotationally symmetric shape with respect to the center line of the mounting hole 5, that is, two quadrangular surfaces. In addition to having a front-to-back inverted symmetric shape with respect to 2, the two first and second side surfaces 3 and 4 also have a front-to-back inverted symmetric shape.

Then, the two one corner C positioned on one diagonal line of the square surface 2 with the corner edge 6 is formed, the Henryo of twos square surface 2 connected to the corner portion C The main cutting edge 7 and the sub cutting edge 8 are formed respectively. In the present embodiment, the main cutting edge 7 is formed on the side edge portion of the quadrangular surface 2 intersecting the first side surface 3, and the sub cutting edge 8 is formed on the side edge portion of the quadrangle surface 2 intersecting the second side surface 4. It is formed. Here, in the insert body 1 of the present embodiment, the distance between the two quadrangular surfaces 2 is larger than the length of the ridge portion of the quadrangular surface 2 on which the secondary cutting edge 8 is formed. This is the insert body 1 of the so-called vertical blade type cutting insert.

When viewed from the direction facing the quadrangular surface 2, the corner blade 6 has a convex curved shape such as a 1/4 convex arc, and the main cutting blade 7 has a linear shape or a curved shape such as a convex arc having an extremely large radius. It is connected so as to be in contact with the corner blade 6. Similarly, when viewed from the direction facing the square surface 2, the secondary cutting edge 8 has a linear first secondary cutting edge 8a connected so as to be in contact with the corner blade 6 and a first secondary cutting edge on the side opposite to the corner blade 6. The cutting edge 8a is provided with a second secondary cutting edge 8b that intersects the cutting edge 8a at an obtuse angle, and the main cutting edge 7 and the first secondary cutting edge 8a are formed at a substantially right angle or slightly sharper than a right angle via the corner blade 6. It extends in the direction of intersection.

Further, on the quadrangular surface 2, on the inner peripheral side of the corner blade 6, the main cutting blade 7, and the sub cutting blade 8, a corner rake surface 9 connected to the corner blade 6 and a main rake surface connected to the main cutting blade 7 are formed. 10 and a secondary rake face 11 connected to the secondary cutting edge 8 are formed. Further, at the central portion of the quadrangular surface 2 on the inner peripheral side of the corner rake surface 9, the main rake surface 10, and the sub rake surface 11, the center lines of the two quadrangular surfaces 2 pass through the center lines of the mounting holes 5. A flat surface 12 perpendicular to the orthogonal straight lines is formed.

The corner rake face 9, the main rake face 10, and the sub rake face 11 are all opposite quadrangular surfaces 2 as they move away from the corner blade 6, the main cutting blade 7, and the sub cutting blade 8 toward the inner peripheral side of the quadrangular surface 2. The first corner rake face 9a, the first main rake face 10a, the first sub rake face 11a, which are inclined toward the side, and the first corner rake face 9a, the first main rake face 10a, which are further connected to the inner peripheral side thereof, The second corner rake surface 9b and the second main rake that are connected to the flat surface 12 and are inclined toward the opposite quadrangular surface 2 side toward the inner peripheral side of the quadrangular surface 2 at a steeper angle than the first secondary rake surface 11a. It has a surface 10b and a second secondary rake surface 11b.

Then, the these first corner rake face 9a, and the portion continuous with the first corner rake face 9a of the first main rake face 10a and the first sub rake face 11a, the square to the one diagonal of the rectangle face 2 It is arranged on one inclined plane that inclines toward the inside of the surface 2 and toward the opposite quadrangular surface 2. In the present embodiment, substantially the entire first corner rake face 9a, the first main rake face 10a, and the first sub rake face 11a are arranged on such an inclined plane. That is, the corner blade 6 and the first corner rake surface 9a of one corner portion C, the main cutting blade 7 and the first main rake surface 10a, the first sub cutting blade 8a, and the first sub rake surface connected to the corner blade 6. 11a is formed so as to be positioned in a straight line as shown in FIGS. 2 and 3 when viewed from a direction along the inclined plane.

Therefore, by arranging the first corner rake face 9a, the first main rake face 10a, and the first sub rake face 11a on the inclined plane in this way, the corner blade 6 formed in one corner portion C is formed. As shown in FIGS. 6 and 7, the main cutting blade 7 and the first secondary cutting blade 8a connected thereto have the corner blade 6 most protruding on the quadrangular surface 2, and the main cutting blade 7 and the first secondary cutting blade 8a are As the distance from the corner blade 6 increases, the blade gradually inclines toward the opposite quadrangular surface 2 side, and the first and second side surfaces 3 and 4 exhibit a parallel quadrilateral shape. As shown in FIG. 7, the second secondary cutting edge 8b is inclined toward the opposite quadrangular surface 2 side with the same inclination as the first secondary cutting edge 8a when viewed from the direction facing the second side surface 4. Later, it is cut off in a concave curve shape and is connected to the main cutting edge 7 on the other corner portion C side of one quadrangular surface 2.

Further, in the present embodiment, the first corner rake face 9a, the first main rake face 10a, the first sub rake face 11a and the second corner rake face 9b, the second main rake face 10b, and the second sub rake face 11b The intersecting ridge line has a convex curve shape such as a 1/4 convex arc at the corner portion C as shown in FIG. 5 when viewed from the direction facing the quadrangular surface 2. However, the radius of this crossing ridge is larger than the radius of the corner blade 6 when viewed from the same direction.

Therefore, the distance from the corner blade 6, the main cutting blade 7, the first sub cutting blade 8a to the crossing ridge line, that is, the width of the first corner rake face 9a, the first main rake face 10a, and the first sub rake face 11a is determined. It is the largest on the inner peripheral side of the corner blade 6 on the quadrangular surface 2, and gradually decreases as it is separated from the corner blade 6 along the main cutting blade 7 and the first sub cutting blade 8a. The width of the first main rake face 10a is set to be substantially constant in the corner portion C at a portion away from the portion where the crossed ridge line has a convex curve shape.

On the other hand, the corner relief surface 13 of the corner blade 6 is formed on the corner portion C side of the intersecting ridge line portion where the first and second side surfaces 3 and 4 intersect, and the main cutting blade of the first side surface 3 is formed. On the 7 side and the secondary cutting edge 8 side of the second side surface 4, the main flank surface 14 and the sub flank surface 15 of the main cutting blade 7 and the sub cutting blade 8 are formed, respectively. The sub-relief surface 15 includes a first sub-relief surface 15a connected to the first sub-cutting blade 8a and a second sub-relief surface 15b connected to the second sub-cutting blade 8b. The corner flank surface 13 is a convex curved surface such as a substantially 1/4 cylindrical surface curved between the main flank surface 14 and the sub flank surface 15 and connected to the corner blade 6, and the main flank surface 14 is flat or has a radius of curvature. The first and second secondary relief surfaces 15a and 15b are planar shapes that intersect at obtuse angles.

Further, of these, the corner flank surface 13, the main flank surface 14, and the second sub flank surface 15b are separated from the corner blade 6, the main cutting blade 7, and the second sub cutting blade 8b, respectively, and are opposite to the quadrangular surface 2 side. It is slightly inclined toward the outside of the insert body 1 toward the direction of. Therefore, the second secondary flank surface 15b is in a direction that intersects the flat surface 12 on the quadrangular surface 2 side opposite to the quadrangular surface 2 where the second secondary flank surface 15b intersects at an acute angle slightly more than a right angle. Be placed.

Further, the corner flank 13 is the central portion of the convex curve formed by the corner blade 6 when the flank width from the corner blade 6 toward the opposite quadrangular surface 2 side is viewed from the direction facing the quadrangular surface 2. It is the largest and gradually decreases toward both ends. On the other hand, the flank width of the main flank 14 gradually decreases as the distance from the corner portion C, and the flank widths of the first and second sub flanks 15a and 15b gradually increase as the distance from the corner portion C.

The portion of one first side surface 3 between the two main escape surfaces 14 on the quadrangular surface 2 side is a plane perpendicular to the center line of the mounting hole 5, and the mounting hole 5 is opened in this plane portion. There is. Therefore, the second secondary flank surface 15b is arranged in a direction in which the second secondary flank surface 15b intersects the plane portion on the first side surface 3 opposite to the adjacent first side surface 3 at an acute angle slightly more than a right angle. Will be done. On the other hand, in the present embodiment, the two first sub-escape surfaces 15a on the one second side surface 4 intersect with each other at an obtuse angle at the central portion of the second side surface 4, and the second side surface 4 accordingly. The two second secondary flanks 15b on the side surface 4 of the above surface 4 are separated from each other without intersecting each other. Further, the area of each second secondary flank surface 15b is larger than the area of each individual first secondary flank surface 15a.

The cutting insert of the present embodiment configured as described above is a cutting tool having a replaceable cutting edge according to an embodiment of the present invention, at the tip of a columnar tool body 21 centered on the axis O as shown in FIG. It is detachably attached to the formed insert attachment seat 22 by a clamp screw 23. Then, while the tool body 21 is rotated around the axis O in the tool rotation direction T, it is sent out in a direction intersecting the axis O, so that, for example, a cutting process (rolling process) of a work material such as a die is performed. Used for.

A plurality of chip discharge grooves 24 that open to the tip surface of the tool body 21 and extend toward the rear end side are formed on the outer periphery of the tip portion of the tool body 21 at intervals in the circumferential direction, and the insert mounting seat 22 is formed of these. It is formed on the outer peripheral portion of the tip of the wall surface of the chip discharge groove 24 facing the tool rotation direction T. The insert mounting seat 22 includes a flat bottom surface facing the outer peripheral side of the tool body 21, a wall surface extending from the bottom surface to the outer peripheral side and facing the tool rotation direction T, and a wall surface facing the tip end side of the tool body 21. A screw hole (not shown) into which the clamp screw 23 is screwed is formed on the bottom surface, and a convex portion having a flat protruding end surface is formed on the wall surface facing the tool rotation direction T, and the outer circumference of the wall surface facing the tip end side of the tool body 21. On the side, an inclined plane is formed which is slightly inclined toward the tip side toward the outer peripheral side and the tool rotation direction T side.

In such an insert mounting seat 22, in the cutting insert of the above embodiment, one quadrangular surface 2 of the insert body 1 is directed in the tool rotation direction T, and the quadrangular surface 2 opposite to the one quadrangular surface 2 is described above. The flat surface 12 is brought into contact with the protruding end surface of the convex portion, one first side surface 3 is directed to the outer peripheral side of the tool body 21, and the first side surface 3 opposite to the first side surface 3 is directed. The side surface 3 is brought into contact with the bottom surface, one second side surface 4 is directed toward the tip end side of the tool body 21, and the tool body of the second side surface 4 opposite to the one second side surface 4. The second secondary relief surface 15b located on the outer peripheral side of the 21 is brought into contact with the inclined plane of the wall surface facing the tip end side of the tool body 21 and seated. Furthermore, by the mounting hole 5 through the insertion has been the clamping screw 23 screwed into the screw hole, the insert body 1 while being pressed by the bottom surface, two wall surfaces are also pressed to the corner side intersecting detachable Can be installed.

In the state of being attached to the insert mounting seat 22 in this way, the corner blade 6 formed in one corner portion C of the one square surface 2 of the insert main body 1 is projected toward the outer peripheral side of the tip of the tool main body 21. The main cutting blade 7 connected to the corner blade 6 is projected toward the outer peripheral side of the tool body 21, and the sub cutting blade 8 connected to the corner blade 6 is projected toward the tip end side of the tool body 21. The rotation locus around the axis O of the main cutting edge 7 is substantially positioned on one cylindrical surface centered on the axis O between the cutting inserts attached to the plurality of insert mounting seats 22, and is located on the outer peripheral side of the tool body 21. The first side surface 3 of the insert body 1 directed toward is positioned inside the cylindrical surface and is provided with a relief on the outer peripheral side.

Further, the auxiliary cutting blade 8 has the rotation locus of the first auxiliary cutting blade 8a substantially positioned on one plane perpendicular to the axis O between the cutting inserts attached to the plurality of insert mounting seats 22, and the tool body. The second side surface 4 of the insert body 1 facing the tip end side of the 21 is positioned on the rear end side of the tool body 21 with respect to this plane surface, and a relief on the tip end side is provided. Further, the second secondary cutting edge 8b directed toward the tip end side of the tool body 21 that intersects the first secondary cutting edge 8a at an obtuse angle when viewed from the direction facing the rectangular surface 2 faces the inner peripheral side of the tool body 21. The second secondary relief surface 15b and the first secondary relief surface 15a, which are inclined toward the rear end side according to the above and are connected to the side opposite to the tool rotation direction T of the second secondary cutting edge 8b, are also different from the tool rotation direction T. A relief is given by inclining toward the rear end side of the tool body 21 toward the opposite side.

In the blade tip exchange type cutting tool (rolling tool) to which the cutting insert is attached in this way, the tool body 21 is rotated in the tool rotation direction T around the axis O as described above in normal shoulder cutting or the like. , Is sent out in a direction orthogonal to the axis O, and cutting is performed by the first sub cutting edge 8a of the corner blade 6, the main cutting edge 7, and the sub cutting edge 8. Further, when the tool body 21 is slightly obliquely fed toward the tip side in the direction orthogonal to the axis O and the tip side in the axis O direction to perform the ramping process, these corner blades 6, the main cutting blade 7, and the first sub In addition to the cutting edge 8a, the second secondary cutting edge 8b is also used for cutting.

In the recess formed in the work material by such shoulder cutting or ramping, the radius of the corner where the wall surface cut by the main cutting edge 7 and the bottom surface cut by the sub cutting edge 8 intersect is set. If the sizes are different, cutting inserts having different radii of the corner blades 6 for cutting the corners are used. In such a case, in the cutting insert of the present embodiment, as shown in FIGS. 1 to 7, a cutting insert having the smallest radius of the corner blade 6 of the insert body 1 is manufactured, and the insert body 1 is used. As shown by the two-point chain line L in FIGS. 4 and 8, the corner flank 13, the main flank 14, and the sub flank around the corner C have a large radius so that the corner blade 6 has a large radius. By polishing 15, a corner blade 6 having a desired different radius is formed, and cutting is performed using such a cutting insert.

At this time, in the cutting insert having the above configuration, in the insert body 1 having the smallest radius of the corner blade 6, the first corner quadrilateral surface 9a connected to the corner blade 6 and the first main quadrangular surface 10a connected to the main cutting blade 7 and the sub The portion of the first secondary rake face 11a connected to the cutting edge 8 connected to the first corner rake face 9a is a quadrangular surface as it goes toward the inside of the quadrangular surface 2 in one diagonal direction of the quadrangular surface 2 of the insert body 1. It is arranged on one inclined plane that is inclined toward the quadrangular surface 2 side opposite to 2. Therefore, if the corner flank 13, the main flank 14, and the sub flank 15 are polished while maintaining a clearance angle equal to that of the original cutting insert having the smallest radius of the corner blade 6, these and one of the above inclinations can be obtained. The rake angle and blade angle of the corner blade 6, the main cutting blade 7, and the sub cutting blade 8 located on the flat surface do not change.

Therefore, even if the cutting inserts have different radii of the corner blades 6, it is possible to suppress the change in the cutting performance, and even if the radii of the corner blades 6 change, it is possible to perform the cutting under the same cutting conditions and to cut. It is possible to prevent variations in the life of the insert and facilitate insert management. Further, when the first corner rake face 9a and the first main rake face 10a and the first sub rake face 11a of the portion connected to the first corner rake face 9a are arranged on one inclined plane in this way, they are connected to these portions. Since the chips generated by the corner blade 6, the main cutting blade 7, and the sub cutting blade 8 flow out along this inclined plane without interfering with each other, there is an advantage that the chip discharging property can be improved. ..

Further, in the cutting insert of the present embodiment, the secondary cutting blade 8 is connected to the linear first secondary cutting blade 8a connected to the corner blade 6 and the side opposite to the corner blade 6 of the first secondary cutting blade 8a. It is provided with a second secondary cutting edge 8b used for ramping as described above, and these first and second secondary cutting edges 8a and 8b have an obtuse angle when viewed from a direction facing the square surface 2. It intersects. Therefore, the first and second secondary flanks 15a and 15b connected to the first and second secondary cutting blades 8a and 8b are also formed so as to intersect at an obtuse angle.

Therefore, even during such ramping or normal shoulder cutting, the second secondary cutting edge 8b connected to the first secondary cutting edge 8a used for cutting and the second secondary cutting edge 8b and the second secondary cutting edge 8b are connected to the first secondary cutting edge 8a. The second secondary relief surface 15b connected to 8b can be arranged so as to be far away from the machined surface (bottom surface of the recess) formed on the work material by the first secondary cutting edge 8a. Therefore, as described above, the tip side of the second side surface 4 of the insert body 1 facing the tip side of the tool body 21 with respect to one plane perpendicular to the axis O where the first secondary cutting edge 8a is located. The axial rake angle of the first secondary cutting edge 8a and the main cutting edge 7 can be set to be relatively large on the regular angle side, and the main cutting edge 7 and the first secondary cutting edge 8a can be set relatively large. The sharpness of the blade can be sharpened to reduce cutting resistance, and the machined surface can be prevented from being scratched to improve the machined quality.

Further, in the present embodiment, the first and second secondary flanks 15a and 15b intersect at an obtuse angle, and the two first secondary flanks 15a on one second side surface 4 also have an obtuse angle. By intersecting with each other and the two second secondary flanks 15b are separated from each other without intersecting with each other, the two first and second secondary flanks 15a of these one second side surface 4 are separated from each other. 15b will be located on independent planes without being flush with each other. Therefore, even when the individual first and second secondary flank surfaces 15a and 15b are formed by polishing, the polishing area of each can be reduced, and efficient cutting inserts can be manufactured.

Further, in the cutting insert of the present embodiment, the second sub-relief surface 15b having a larger area than the first sub-relief surface 15a is on the side of the quadrangular surface 2 opposite to the quadrangular surface 2 where the second sub-relief surface 15b intersects. The flat surface portion on the first side surface 3 opposite to the first side surface 3 which is arranged in the direction of intersecting the flat surface 12 of the above surface at an acute angle slightly more than a right angle and the second secondary relief surface 15b is adjacent to the first side surface 3. It is also arranged in a direction that intersects at an acute angle slightly more than a right angle. In the cutting tool with a replaceable cutting edge of the present embodiment, the second secondary relief surface 15b located on the outer peripheral side of the second side surface 4 facing the rear end side of the tool body 21 is the tip side of the tool body 21. The cutting insert is attached by being brought into contact with and pressed against an inclined plane that is slightly inclined toward the tip side toward the outer peripheral side of the wall surface facing the tool and toward the T side in the tool rotation direction.

Therefore, the intersection angle of the second secondary relief surface 15b with respect to the flat surface 12 on the opposite quadrangular surface 2 side and the flat surface portion on the opposite first side surface 3 is the tool rotation direction of the inclined plane of the insert mounting seat 22. If the angle of inclination with respect to the tip surface of the convex portion on the wall surface facing T and the bottom surface facing the outer peripheral side of the tool body 21 is set to be equal, when the cutting insert is pressed by the clamp screw 23 and attached, the second secondary relief having a large area is set. The surface 15b can be guided by the inclined plane so that the insert body 1 can be firmly pressed against the bottom surface and the tip surface of the insert mounting seat 22, and the mounting rigidity of the cutting insert can be improved. Further, when the second secondary relief surface 15b comes into contact with such an inclined plane, it is possible to prevent the insert body 1 from coming off toward the tool rotation direction T or the outer peripheral side of the tool body 21.

Further, in the cutting insert of the present embodiment, the corner flank surface 13 and the main flank surface 14 are slightly toward the outside of the insert body 1 as they are separated from the corner blade 6 and the main cutting blade 7 and toward the opposite square surface 2 side. In the cutting tool with a replaceable blade tip of the present embodiment, the tip surface of the convex portion is different from the tool rotation direction T of the insert body 1 on the wall surface of the insert mounting seat 22 facing the tool rotation direction T. Since it comes into contact with the flat surface 12 at the center of the square surface 2 facing the opposite side, the corner blade 6 arranged on the rear end side of the tool body 21 on the side opposite to the tool rotation direction T and the main cutting blade connected thereto 7 does not interfere with the corners of the bottom surface of the insert mounting seat 22 and the two wall surfaces. Then, if these corners are formed according to the cutting insert having the smallest radius of the corner blade 6 of the insert body 1, even when the cutting insert having a large radius of the corner blade 6 is attached as described above. , It is possible to prevent such interference from occurring.

On the other hand, in the insert body 1 of the cutting insert of the present embodiment, the distance between the two quadrangular surfaces 2 is larger than the length of the ridge portion of the quadrangular surfaces 2 on which the secondary cutting edge 8 is formed. It is said to be the insert body 1 of a large vertical blade type cutting insert. Therefore, the first corner rake face 9a leading to 2 each of the two rectangles face two of the corner portion C, and a portion connected to the first main rake face 10a and the first first corner rake face 9a of the secondary rake surface As described above, even if they are arranged on one inclined plane that is inclined toward the inside of the quadrangular surface 2 in the diagonal direction connecting these corner portions C and toward the opposite quadrangular surface 2, both quadrangles. A sufficient wall thickness can be secured in the insert main body 1 between the surfaces 2, and it is possible to prevent the insert main body 1 from being damaged even if an excessive cutting load is applied.

1 Insert body 2 Square surface 3 1st side surface 4 2nd side surface 5 Mounting hole 6 Corner blade 7 Main cutting blade 8 Secondary cutting blade 8a 1st secondary cutting blade 8b 2nd secondary cutting blade 9 Corner rake surface 9a 1st corner Scoop surface 9b 2nd corner rake surface 10 Main rake surface 10a 1st main rake surface 10b 2nd main rake surface 11 Sub rake surface 11a 1st secondary rake surface 11b 2nd secondary rake surface 12 Flat surface 13 Corner escape surface 14 Main escape Surface 15 Secondary relief surface 15a 1st secondary relief surface 15b 2nd secondary relief surface 21 Tool body 22 Insert mounting seat 23 Clamp screw 24 Chip discharge groove C Corner part of square surface 2 O Axis of tool body 21 T Tool rotation direction

Claims (3)

It has an insert body with two quadrilateral faces facing each other and four sides arranged around these quadrangular faces.
A corner blade is formed at one of the two corner portions located on one diagonal line of the quadrangular surface, and a main cutting blade and a sub blade are formed at each of the two edge portions of the quadrangular surface connected to the corner portion. Each cutting edge is formed,
On the quadrangular surface, a first corner rake surface connected to the corner blade, a first main rake surface connected to the main cutting blade, and a first sub rake surface connected to the sub cutting blade are formed.
The first corner rake plane and the portion of the first main rake plane and the first sub rake plane that are connected to the first corner rake plane are opposite to each other in the diagonal direction toward the inside of the quadrangular plane. It is arranged on one inclined plane that inclines toward the quadrangular surface side, and
The sub-cutting blade includes a linear first sub-cutting blade connected to the corner blade and a second sub-cutting blade connected to the side opposite to the corner blade of the first sub-cutting blade. The second secondary cutting edge intersects at an obtuse angle when viewed from the direction facing the quadrangular surface.
The second secondary cutting edge is connected to the main cutting edge extending from the one corner portion on the other corner portion side of the quadrangular surface .
The rake face is connected to the inner peripheral side of the first corner rake face, the first main rake face, and the first sub rake face, and these first corner rake face, first main rake face, and first sub rake face. A second corner rake face, a second main rake face, and a second sub rake face that incline toward the opposite quadrangular surface side toward the inner peripheral side of the quadrangular surface at a steeper angle than the surface are formed.
The intersection ridge line between the first corner rake surface, the first main rake surface, the first sub rake surface, the second corner rake surface, the second main rake surface, and the second sub rake surface is a quadrangle. A convex curve is formed on one corner side when viewed from the direction facing the surface, and the radius of the intersecting ridge line forming the convex curve is the radius when viewed from the direction facing the quadrangular surface. A cutting insert characterized by being larger than the radius of the corner blade. It has an insert body with two quadrilateral faces facing each other and four sides arranged around these quadrangular faces.
A corner blade is formed at one of the two corner portions located on one diagonal line of the quadrangular surface, and a main cutting blade and a sub blade are formed at each of the two edge portions of the quadrangular surface connected to the corner portion. Each cutting edge is formed,
On the quadrangular surface, a first corner rake surface connected to the corner blade, a first main rake surface connected to the main cutting blade, and a first sub rake surface connected to the sub cutting blade are formed.
The first corner rake plane and the portion of the first main rake plane and the first sub rake plane that are connected to the first corner rake plane are opposite to each other in the diagonal direction toward the inside of the quadrangular plane. It is arranged on one inclined plane that inclines toward the quadrangular surface side, and
The sub-cutting blade includes a linear first sub-cutting blade connected to the corner blade and a second sub-cutting blade connected to the side opposite to the corner blade of the first sub-cutting blade. The second secondary cutting edge intersects at an obtuse angle when viewed from the direction facing the quadrangular surface.
The second secondary cutting edge is connected to the main cutting edge extending from the one corner portion on the other corner portion side of the quadrangular surface.
The insert body is a vertical blade type insert body in which the distance between the two quadrangular surfaces is larger than the length of the edge portion of the quadrangular surface on which the secondary cutting edge is formed. A cutting insert that features. An insert mounting seat is formed on the outer periphery of the tip of the tool body that is rotated around the axis, and the cutting insert according to claim 1 or 2 directs one of the square surfaces in the tool rotation direction on the insert mounting seat. The corner blade formed on one corner portion of the one square surface is projected toward the outer peripheral side of the tip of the tool body, and the main cutting blade connected to the corner blade is projected on the outer peripheral side of the tool body. A cutting tool with a replaceable cutting edge, characterized in that the auxiliary cutting blade connected to the corner blade is projected toward the tip end side of the tool body and is detachably attached.

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