JP2008229744A - Cutting insert and insert removable rotary cutting tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a tool angle and a clearance angle of a sub-cutting blade from being limited by the main cutting blade. <P>SOLUTION: This cutting insert 1 is shaped like a quadrangular plate in its outline, and provided with two quadrangular surfaces 2 and four side surfaces 3. Two quadrangular surfaces 2 are disposed to twist around the center line C, and the main cutting blade 5 taking the quadrangular surface 2 as a flank and the side surface 3 as a cutting face is formed on the respective side ridge parts of two quadrangular surfaces 2 extending from one end of the side ridge part toward the other end side. A sub-cutting blade 6 connected to the main cutting blade 5 at one end of one side ridge part is formed on the intersecting ridge line part of the adjacent side surfaces 3, a projecting part 7 forming a projection to a cutting face at the other end of the main cutting blade 5 formed on the other side ridge part is provided on the other end side of the other side ridge part intersecting at one end, and a flank 6A of the sub-cutting blade 6 is formed on the projecting part 7. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention has a rectangular flat plate shape, and a cutting insert arranged so that two rectangular surfaces on which the main cutting edge is formed at the side ridge portion are twisted around the center line, and the cutting insert is detachable The present invention relates to an insert detachable rolling tool that is mounted.

  Conventionally, as a cutting tool used when cutting a work material, for example, as shown in Patent Document 1, a cutting insert having a cutting edge is attached to and detached from the outer periphery of a tip of a tool body rotated around an axis. An insert detachable rolling tool that can be mounted is known. Here, in the insert detachable rolling tool described in Patent Document 1, the cutting insert has a rectangular flat plate shape, and one of the four side surfaces around the rectangular surface is a rake surface. A cutting insert of a so-called vertical blade is provided in which a cutting edge extending along a side ridge where the square surface and the rake face intersect is provided at each corner.

Further, Patent Document 2 to Patent Document 4 describe that one rectangular surface and the other rectangular surface are used as cutting inserts used for turning to cut the outer peripheral surface of a rotating work material even with cutting inserts of the same vertical blade. Cutting inserts have been proposed that are arranged so that they twist together. In the cutting insert having such a configuration, when one of the cutting edges formed on the side ridge portion of one quadrangular surface is used, the cutting blade formed on the other quadrangular surface side is used as a work material. Interference can be prevented, and all of the cutting edges formed on the eight side ridges of these two quadrangular surfaces can be used sequentially.
Japanese Patent Laid-Open No. 08-39324 U.S. Pat. No. 3,490,117 JP 57-27603 A U.S. Pat. No. 3,142,110

  By the way, in the insert detachable type rolling tool as described in Patent Document 1, a sub-cutting blade extending toward the inner peripheral side is formed at the tip of a cutting blade (main cutting blade) positioned on the outer periphery of the tip of the tool body. However, when such a secondary cutting edge is to be formed on a cutting insert in which two rectangular surfaces are twisted as described in Patent Documents 2 to 4, the secondary cutting edge is formed between adjacent side surfaces. The crossing ridge line portion is formed so as to cross one end portion of the side ridge portion where the main cutting edge is formed.

  Therefore, the side surface that is connected to the side ridge portion where the main cutting edge is formed and is used as the rake face is a rake face of the sub cutting edge, and the side surface is formed at the intersecting ridge line portion where the sub cutting edge is formed. The other side that intersects with this is the flank of this sub-cutting blade, but the other side that is the flank of this sub-cutting blade is another side ridge that is connected to the other side at the same time, that is, the side ridge. It becomes the rake face of the main cutting edge formed in the other edge part which cross | intersects this edge part at the one end part of a part. For this reason, it is unavoidable that the rake angle of the secondary cutting edge and the tool angle are restricted by the rake angle of the main cutting edge formed on the other side ridges, for example, the rake angle of the main cutting edge When a breaker groove is formed along the main cutting edge in order to obtain a sharp sharpness by enlarging to the regular angle side, the breaker grooves intersect with each other at the intersecting ridge line portion to form a secondary cutting edge. Therefore, there is a possibility that the knife angle of the auxiliary cutting edge becomes small and the chipping resistance is impaired.

  The present invention has been made under such a background. As described above, a cutting insert having a vertical blade arranged so that one rectangular surface and the other rectangular surface are twisted with each other, particularly an insert detachable rolling tool. Even when forming a secondary cutting edge that extends from the tip of the main cutting edge to the inner periphery of the tool body when used for a cutting tool, the tool angle or clearance angle of the secondary cutting edge is the rake angle of the main cutting edge, etc. It is an object of the present invention to provide a cutting insert that can be prevented from being restricted by the cutting tool and an insert detachable rolling tool equipped with the cutting insert.

  In order to solve the above problems and achieve such an object, the cutting insert of the present invention has a rectangular flat plate shape, two rectangular surfaces, and four side surfaces. The surface is arranged so as to be twisted around the center line intersecting the quadrangular surface, and each of the side ridges of the two quadrangular surfaces has the quadrangular surface connected to the side ridge as a flank and the above A main cutting edge having a rake face on the side surface is formed so as to extend from one end portion of the side ridge portion toward the other end portion side. A secondary cutting edge that is continuous with the main cutting edge is formed at one end of the other side edge of the rectangular surface that intersects at one end of the one side edge. Convex with respect to the rake face at the other end of the main cutting edge formed on the side ridge Convex portion is provided consisting, characterized in that the flank of the auxiliary cutting edge is formed on the convex portion.

  In the cutting insert having such a configuration, even if the auxiliary cutting edge is formed at the intersecting ridge line portion between the adjacent side surfaces as described above, the flank of the auxiliary cutting edge is the other end of the other side ridge portion. Since it is formed in a convex part that is convex to the rake face of the main cutting edge on the part side, the rake angle of the main cutting edge in the other side ridge part, etc., of the sub cutting edge formed in the convex part The clearance angle of the flank and the blade angle are not restricted. That is, since the side ridge portion of the rectangular surface is composed of a main cutting edge extending from one end portion to the other end side and a convex portion of the other end portion, the rake angle of the main cutting edge, etc. Regardless of this, the clearance angle of the secondary cutting edge and the blade angle associated with this clearance angle can be set arbitrarily. Even if a breaker groove is formed along the main cutting edge on the side surface, the secondary cutting edge It is possible to prevent the clearance angle from becoming unnecessarily large, to secure a sufficient blade angle, and to improve the fracture resistance.

  The insert detachable rolling tool of the present invention has a tool body that rotates about the axis, and the cutting insert having the above-described configuration is mounted on the mounting seat formed on the outer periphery of the tip of the tool body. One of the square faces is directed to the outer periphery of the tool body, the one end of one side ridge of the one square face is projected from the tip of the tool body, and the one side ridge The main cutting edge formed on the tool rotation direction side is detachably attached to the auxiliary cutting edge connected to the main cutting edge at the one end of the one side ridge, Since the other quadrangular surface of the two quadrangular surfaces is positioned on the rear end side in the axial direction, the main cutting edge or the convex portion formed on each side ridge portion of the other quadrangular surface is the tool. Sub-cut connected to one end protruding from the tip of the main body Not able to or interfere with the working surface formed by thus successively becomes possible to use all of the two of the eight cutting edges formed on Henryo unit square surface.

  Further, in the cutting insert, when the main cutting edge is formed in a convex curve shape when viewed from the center line direction, when attached to the tool body of the insert detachable rolling tool in this way, On the other hand, the axial rake angle can be increased to the positive angle side on the other end side of the main cutting edge to be positioned on the rear end side of the tool body. The thickness of the part from the one end part to the other end part side of the above-mentioned side ridge part in which is formed can be secured to increase the cutting edge strength, and the fracture resistance of the main cutting edge can be improved. Further, by forming a chamfer portion at one end of the side ridge portion that intersects the main cutting edge and the auxiliary cutting edge connected at the one end at an obtuse angle, the auxiliary cutting edge and the main cutting at the one end side are formed. It is possible to further improve the fracture resistance by further improving the cutting edge strength of the blade.

  On the other hand, by providing different indices at each corner of the rectangular surface, for example, based on these indices, for example, the main cutting edge of the side edge where the one end is adjacent to the corner, or the sub-cuts connected to the edge. It is possible to determine whether the blade is unused or used, and prevent these cutting blades from being used again or conversely to prevent the cutting insert from being discarded while the cutting blade is unused. Can do. Furthermore, when the breaker grooves are respectively formed along the main cutting edge on the two rectangular surface sides of the side surface, a protrusion is formed between the breaker grooves. By attaching the cutting insert to the mounting seat of the insert detachable rolling tool with the protruding end surface as the seating surface, the cutting insert can be stably attached to the tool body even if such a breaker groove is formed. It can be attached.

  Thus, according to the cutting insert of the present invention, even if the auxiliary cutting edge is formed at the intersecting ridge line portion of the side surfaces connected to the side ridge portion where the main cutting edge is formed, the rake angle of the main cutting edge, etc. Regardless of this, since the clearance angle and the blade angle of the auxiliary cutting edge can be set, the cutting edge strength can be secured to improve the fracture resistance, and the life of the cutting insert can be extended. Further, according to the insert detachable rolling tool of the present invention to which such a cutting insert is attached, all of the main cutting edge formed on the eight side ridges of the cutting insert and the sub cutting edges connected thereto are sequentially provided. Since it can be used, combined with the long life of the cutting insert, it is possible to promote economical and efficient cutting.

  1 to 4 show a cutting insert 1 according to an embodiment of the present invention, and FIGS. 5 to 9 show an insert detachable rolling tool according to an embodiment of the present invention to which the cutting insert 1 is attached. (Milling cutter). The cutting insert 1 of the present embodiment is the above-described vertical cutting cutting insert, which is made of a hard material such as cemented carbide, and has an outer shape of a rectangular flat plate, more specifically, a substantially square flat plate. Two square surfaces, that is, square surfaces 2, and four side surfaces 3 arranged around the square surfaces 2 and intersecting the square surfaces 2 are provided.

  At the center of the square surface 2, an attachment hole 4 that penetrates the cutting insert 1 in the thickness direction (vertical direction in FIG. 3) is opened. The center line C of the attachment hole 4 is the square surface 2. It is arranged so as to intersect (orthogonal) the square surface 2 through the center. Further, the cutting insert 1 of the present embodiment has a rotationally symmetric shape by 90 ° around the center line C except for an index described later, and also has a symmetrical shape when the two square surfaces 2 are reversed. It is formed to become. Further, as shown in FIGS. 2 and 4, the cutting insert 1 is formed so that the two square surfaces 2 are twisted with each other at a predetermined twist angle α around the center line C. The twist angle α is preferably in the range of 3 ° to 20 °, and in this embodiment, 6 °.

  A main cutting edge 5 extending from one end to the other end side is formed on a total of eight side ridges, four of each of the two square surfaces 2 and adjacent in the circumferential direction. Sub-cutting edges 6 extending inward in the thickness direction in the thickness direction are formed respectively at the one end of each side ridge at the intersecting ridges between the side surfaces 3. . Here, since this embodiment is a cutting insert of a vertical blade as described above, the two square surfaces 2 are used as flank surfaces of the main cutting blade 5 formed on each of the side ridges, and the side surface 3 The rake face of the main cutting edge 5 and the auxiliary cutting edge 6 is formed.

  In this embodiment, as shown in FIG. 2 and FIG. 4, the end of the side ridge portion on the counterclockwise direction side when viewed from the center line C direction with respect to each square surface 2 is The main cutting edge 5 has one end 5A positioned at one end of the side ridge, and extends from the one end toward the other end of the side ridge in the clockwise direction. Yes. Moreover, since the cutting insert 1 of this embodiment is inversion-symmetrical as mentioned above, as shown in FIG. 3, in one side surface 3, the edge parts of both square surfaces 2 are the one end part and the other end part. Are positioned on the opposite side.

  And the convex part 7 is formed in the other end part of these each side ridge part so that it may become convex with respect to the rake face of the main cutting edge 5 in this other end part side, A flank (sub-flank) 6A of the sub-cutting blade 6 is formed. That is, with respect to the main cutting edge 5 formed on one side ridge of the square surface 2, the flank 6A of the auxiliary cutting edge 6 connected to the one end 5A of the main cutting edge 5 at one end thereof is the one. On the other side of the other side ridge of the square surface 2 that intersects the side ridge and the one end, on the rake face on the other side of the main cutting edge 5 formed on the other side ridge It is formed on the protruding convex portion 7.

  Here, in the present embodiment, a concave groove-shaped breaker groove 3A is formed on the side surface 3 along the main cutting edge 5 on both sides of the square surface 2 and between the breaker grooves 3A. Is formed with a protruding portion 3B that is convex with respect to the breaker groove 3A. The protruding portion 3B has a protruding end surface which is a flat surface along the thickness direction, and in the circumferential direction, the twisting angle α of the square surface 2 is bisected when viewed from the center line C direction. The projecting end surface is used as a seating surface when the cutting insert 1 is attached to the insert detachable rolling tool. In addition, a chamfered surface that intersects at an obtuse angle is formed on each protruding end surface at a portion where the protruding portions 3B intersect in the intersecting ridge line portion, and also on the intersecting ridge line portion between this chamfered surface and each protruding end surface, Chamfering is performed so as to face one end of the side ridge, that is, the side where the one end 5A of the main cutting edge 5 is located.

  Further, the breaker groove 3A rises after reaching a position where the cross section perpendicular to the main cutting edge 5 on the bottom surface of the breaker groove 3A is recessed from the main cutting edge 5 toward the protruding portion 3B in the thickness direction. It has a concave curve shape such as a concave arc, and the bottom surface of the breaker groove 3A is substantially the rake face of the main cutting edge 5. Therefore, the main cutting edge 5 is given a positive rake angle. Become. Furthermore, the main cutting edge 5 has a convex curve shape that is convex outward as shown in FIGS. 2 and 4 when viewed from the direction along the center line C, and the breaker groove 3A is also formed as a main cutting edge. In the direction along, the bottom surface is formed so as to bend along the convex curve. However, the convex curve formed by the main cutting edge 5 does not exceed the protruding end surface of the projecting portion 3B, and is closest to the protruding end surface at the center of the main cutting edge 5 so that the one end of the main cutting edge 5 is It is made to retreat gradually as it goes to the 5A side and the other end 5B side. Further, a flat land having a very small width is formed on the main cutting edge 5.

  The convex portion 7 is formed so as to protrude toward the other end of each side ridge portion with respect to the breaker groove 3A formed in this way of the main cutting edge 5, and the main cutting edge 5 Also, as described above, it is formed so as to rise while drawing a concave curve from the other end 5 </ b> B retracted from the central portion, and the protruding height of the protruding portion 3 </ b> B formed on the same side surface 3 is as described above. It is higher than the tip. Therefore, the main cutting edge 5 is used for cutting with the effective cutting edge length from the one end 5A to the other end 5B retracted with respect to the protruding end surface in front of the projection 7. Further, the one end 5A of the main cutting edge 5 and the breaker groove 3A on the one end 5A side of the other side ridge portion intersecting at one end with one side ridge portion where the main cutting edge 5 is formed. It is extended on the convex part 7 of the other end part side.

  The auxiliary cutting edge 6 connected to the one end 5A of the main cutting edge 5 at one end of the side edge extends in a direction substantially orthogonal to the main cutting edge 5 as shown in FIG. ing. Further, the flank 6 </ b> A formed on the convex portion 7 connected to the auxiliary cutting edge 6 is formed as a protruding end surface of the convex portion 7, and slightly recedes as the distance from the auxiliary cutting edge 6 increases. In this way, a desired clearance angle is formed. The back surface of the convex portion 7 from the bottom surface of the breaker groove 3A to the clearance surface 6A at the other end 5B of the main cutting edge 5 remains a concave curve formed by the cross section from the bottom surface of the breaker groove 3A. It is considered as a concave curved surface.

  In the present embodiment, the other side edge of the square surface 2 is between the flank 6A of the auxiliary cutting edge 6 and the square surface 2 serving as the flank on the one end 5A side of the main cutting edge 5. A chamfer surface 8A is formed so as to chamfer the other end side of the portion. As a result, a chamfer portion 8 that intersects the main cutting edge 5 and the auxiliary cutting edge 6 at an obtuse angle is formed at one end of the one side ridge that intersects with the other edge. The blade 6 is connected to the main cutting blade 5 through the chamfer portion 8. Incidentally, the length of the auxiliary cutting edge 6 excluding the chamfer portion 8 is about 1 mm.

  On the other hand, the periphery of the opening of the mounting hole 4 in the square surface 2 serving as the flank of the main cutting edge 5 is a substantially square flat surface 2A perpendicular to the center line C, but the square formed by the flat surface 2A. 2 and 4 when viewed from the direction of the center line C, a twist angle larger than the twist angle α formed by the square surface 2 viewed from the center line C direction is twisted with respect to the square surface 2. It is formed to be. On the other hand, on the side ridge portion side of the square surface 2, a flank portion 2B that is inclined so as to recede in the thickness direction toward the side ridge portion side is formed at the main cutting edge 5 formed on each side ridge portion. Further, it is formed with a substantially constant width along the convex portion 7, and a side ridge is formed between the flank portion 2B and the flat surface 2A with a gentler inclination than the flank portion 2B with respect to the flat surface 2A. An inclined portion 2 </ b> C that recedes in the thickness direction as it goes toward the portion side and gradually becomes wider as it goes from the other end portion side to the one end portion of the side ridge portion is formed.

  Furthermore, a total of eight corners of the two square surfaces 2 are provided at each corner of the square surface 2 so as to be close to one end side of the side ridge portion that becomes the width of the inclined portion 2C thus formed. Indices 9 different from each other are provided. In this embodiment, the index 9 is a number from 1 to 8 as shown in FIG. 2 and FIG. 4 and is displayed by being engraved or projecting at the corner, but one square The surface 2 has an odd number of 1, 3, 5, and 7 in order from the other end of the side ridge to the one end around the periphery from one corner, and the other square surface 2 has the above 1 In the direction from the other end of the side ridge to the one end, the even numbers 2, 4, 6, and 8 are arranged in order from the opposite corners of the corner where the number is displayed. It is assumed that it was established.

  A plurality of such cutting inserts 1 having the same shape and the same size are detachably attached to an insert detachable rolling tool as shown in FIGS. 5 to 9 and used for the machining. This insert detachable type rolling tool has a substantially disk shape in which the tool main body 11 has its tip side (lower side in FIG. 6) enlarged by one step with the axis O as the center. The part is attached to the spindle end of the machine tool and rotated in the tool rotation direction T around the axis O. On the outer periphery of the tip of the tool body 11, a plurality (six in this embodiment) of tip pockets 11A are provided. Insert mounting seats 12 formed at equal intervals in the circumferential direction and formed so as to open to the wall surface facing the tool rotation direction T and the tip end surface of the tool body 11 are connected to the chip pockets 11A. The cutting insert 1 is attached.

  As shown in FIG. 8 with hatching, the insert mounting seat 12 has a substantially square bottom surface 12A facing the outer peripheral side of the tool body 11, and a tool rotation from the bottom surface to the outer peripheral surface of the tip of the tool body 11. It has a wall surface 12B facing the direction T and a wall surface 12C facing the front end side, and a screw hole 12D is formed in the center of the bottom surface 12A. The wall surfaces 12B and 12C are formed with recesses 12E along the corners intersecting the bottom surface 12A. On the outer peripheral surface side of the tool body 11 of the recesses 12E, the protrusions of the side surface 3 of the cutting insert 1 are provided. A protruding portion 12F having a protruding end surface capable of coming into contact with the protruding end surface of the portion 3B is formed. Note that an even smaller recess 12G is formed at the center of the protruding end surface of the protruding portion 12F.

  In the insert mounting seat 12 formed in this way, the cutting insert 1 directs one of the two square surfaces 2 toward the outer peripheral side of the tool main body 11, and one side ridge portion of the one square surface 2. The one end portion of the main body 11 protrudes from the tip of the tool body 11 and the main cutting edge 5 formed on the one side ridge portion is seated toward the tool rotation direction T side. At this time, as shown by hatching in FIG. 9, the other square surface 2 opposite to the one square surface 2 has its flat surface 2 </ b> A closely attached to the bottom surface 12 </ b> A of the insert mounting seat 12. The protrusion 3B formed on the side surface 3 connected to the side ridge opposite to the one side ridge has a protruding end surface as a seating surface on the protruding end surface of the protruding portion 12F of the wall surface 12B. The projecting end surface, which is the seating surface of the projecting portion 3B formed on the side surface 3 opposite to the side surface 3 facing the tip side of the tool body 11, is brought into contact with the projecting end surface of the projecting portion 12F of the wall surface 12C. The cutting screw 1 is detachably mounted on the insert mounting seat 12 by the clamp screw 13 inserted through the mounting hole 4 being screwed into the screw hole 12D.

  Then, in the cutting insert 1 thus mounted on the insert mounting seat 12, the square cutting edge 1 is formed on one square surface 2 so that the main cutting edge 5 formed on the one side ridge portion is located on the outermost periphery of the tool body 11. An outer clearance angle is provided, and the auxiliary cutting edge 6 connected to the main cutting edge 5 at one end of the one side ridge is positioned on a plane perpendicular to the axis O at the forefront of the tool body 11. In addition, a front clearance angle is given to the flank 6A, and the other square surface 2 is entirely formed with respect to the auxiliary cutting edge 6 connected to the main cutting edge 5 at one end of the one side ridge. It is made to be located on the rear end side in the axis O direction. Of course, in the plurality of cutting inserts 1, the rotation trajectories of the main cutting edge 5 and the sub cutting edge 6 coincide with each other, that is, the plurality of cutting inserts 1 have a predetermined angle around the axis O (60 in this embodiment). °) are arranged in rotational symmetry.

  Thus, in the cutting insert 1 used by being attached to the insert detachable rolling tool, the secondary cutting edge 6 used for cutting is connected to one end 5A of the main cutting edge 5 at one end of the one side ridge. The flank 6A is formed on a convex portion 7 that is convex with respect to the rake face of the main cutting edge 5 on the other end side of the other side ridge portion of the square surface 2 that intersects at the one end portion. Therefore, even when the rake face is formed by the bottom surface of the grooved breaker groove 3A as described above as in the present embodiment, the flank angle of the flank face 6A and the knife angle of the auxiliary cutting edge 6 are the main. There is no restriction by the rake angle of the cutting edge 5.

  That is, when the auxiliary cutting edge is formed at the intersecting ridge line portion of the side surfaces 3 where the rake face formed by the bottom surface of the concave groove-shaped breaker groove 3A intersects as it is, the clearance angle of the auxiliary cutting edge is necessary. Although it becomes larger as described above, the cutter angle becomes too small, and the secondary cutting edge is liable to be damaged, resulting in a shortened insert life. However, like the cutting insert 1 having the above configuration, it is formed on the other side ridge. By forming the auxiliary cutting edge 6 and its flank 6A on the convex part 7 formed outside the range of the effective cutting edge length on the other end side than the other end 5B of the main cutting edge 5 thus formed, this other side edge It is possible to arbitrarily set the clearance angle of the flank 6A and the cutter angle of the auxiliary cutting edge 6 regardless of the main cutting edge 5 of the portion. Therefore, according to the cutting insert 1 having the above-described configuration, the clearance angle is set without increasing more than necessary, and on the contrary, the blade angle is sufficiently secured, thereby improving the chipping resistance of the auxiliary cutting edge 6. It is possible to extend the insert life.

  Furthermore, according to the insert detachable type rolling tool in which such a cutting insert 1 is detachably attached as described above, the auxiliary cutting edge 6 in which the flank 6A is thus formed on the convex portion 7 is the auxiliary cutting edge. One end of the side ridge where the main cutting edge 5 connected to 6 is formed protrudes from the tip of the tool body 11 and is attached to the other side opposite to the square surface 2 where the side ridge is formed. Since the other square surface 2 is positioned on the rear end side in the axis O direction of the tool body 11 with respect to the projecting auxiliary cutting edge 6, the square surface 2 is twisted around the center line C. The main cutting edge 5 and the auxiliary cutting edge 6 formed on the side ridge portion of the other square face 2 do not interfere with the processed surface formed by the auxiliary cutting edge 6 and, of course, the other square face 2 The main cutting edge 5 and the auxiliary cutting edge 6 do not interfere with each other. For this reason, in such an insert detachable rolling tool, it is possible to reliably use the eight sets of the main cutting edge 5 and the auxiliary cutting edge 6 formed in one cutting insert 1, and the individual auxiliary cutting edges as described above. Combined with the extension of the insert life due to the improved fracture resistance of the cutting edge 6, it is possible to achieve an economical and efficient rolling process.

  Moreover, in the cutting insert 1 of the present embodiment, different indexes 9 are formed at the corners of the two square surfaces 2, and based on these indexes 9, eight sets of main cutting edges 5 and sub cutting edges are formed. All 6 can be used up without mistakes. That is, it is more economical because the cutting insert 1 is not discarded while the unused main cutting edge 5 and the auxiliary cutting edge 6 remain, while the used main cutting edge 5 and the auxiliary cutting edge are discarded. The blade 6 is not used again and the desired cutting performance cannot be obtained. In the present embodiment, numbers 1 to 8 are provided as the index 9, but alphabets a to h and other different displays may be used as the index 9, for example.

  On the other hand, in the cutting insert 1 of the said embodiment, the main cutting edge 5 is formed so that it may form a convex curve shape seeing from the said centerline C direction, One end 5A of such a main cutting edge 5 is used as the tool main body 11. In the insert detachable rolling tool of the above-described embodiment projected at the tip of the tool, the axial rake angle of the main cutting edge 5 gradually increases toward the regular angle side toward the rear end side of the tool body 11, On the end side, the main cutting edge 5 can be sharpened to reduce cutting resistance. And since the main cutting edge 5 projects in a convex shape in this way, its thickness can be ensured to be large and the cutting edge strength can be improved, so that the convex part 7 is formed at one end of the side ridge on the tip side. Combined with the formation, the main cutting edge 5 can also be provided with a longer life cutting insert with improved fracture resistance.

  In addition, in the cutting insert 1 of this embodiment, the main cutting edge 5 connected to one end portion of the side ridge portion projected from the tip of the tool body 11 in the insert detachable rolling tool is connected to the one end portion. A chamfer portion 8 that intersects the sub cutting edge 6 at an obtuse angle is formed, so that it is possible to avoid the formation of a sharp corner at the portion where the sub cutting edge 6 continues to the main cutting edge 5. Further, it is possible to prevent the insert life from being shortened due to the occurrence of defects from the corners. In this embodiment, the chamfer portion 8 is linear by forming a flat chamfer surface 8A. However, the chamfer surface 8A is a convex curved surface, and the convex chamfer portion 8A is mainly used. The cutting edge 5 and the auxiliary cutting edge 6 may be formed so as to cross an obtuse angle or to be in contact with them.

  Furthermore, in the present embodiment, on the side surface 3 of the cutting insert 1, breaker grooves 3 </ b> A are formed along the main cutting edge 5 on the two rectangular surface 2 sides, and between the breaker grooves 3 </ b> A. The portion is a projecting portion 3B, and the cutting insert 1 is attached and detached by making the projecting end surface of the projecting portion 3B abut the projecting portion 12F formed on the wall surface 12B, 12C of the insert mounting seat 12. It is attached to the type of rolling tool. For this reason, even if the groove-shaped breaker groove 3A as described above is formed, the mounting stability of the cutting insert 1 is not impaired, and high-precision cutting can be performed stably, Such a breaker groove 3A can further reduce cutting resistance and improve chip disposal.

  Moreover, in the present embodiment, a chamfered surface is formed at a portion where the protruding portions 3B of the adjacent side surfaces 3 intersect with each other, and each of the above-mentioned sides is also formed on the intersecting ridge line portion between the chamfered surface and the protruding end surface of the protruding portion 3B. Since the chamfering is applied to the portion facing the one end side of the ridge portion, it is ensured that the chip dischargeability is ensured at this one end portion where the chips are generated from the main cutting edge 5 and the auxiliary cutting edge 6 as well. Can do. Furthermore, the main cutting edge 5 having a convex curve shape as described above is formed so as not to protrude outward from the protruding end surface of the protruding portion 3B from one end 5A to the other end 5B when viewed from the center line C direction. Therefore, the chips generated by the main cutting edge 5 on the one square surface 2 side may cause wear on the main cutting edge 5 on the other square surface 2 side or the breaker groove 3A which is substantially a rake face. In addition, it is possible to use the eight main cutting edges 5 more reliably.

  Although the cutting insert 1 and the insert detachable rolling tool according to the embodiment of the present invention have been described above, the present invention is not limited to this, and can be appropriately changed without departing from the technical idea of the present invention. It is. For example, the cutting insert has a square flat plate shape, but the present invention is not limited to this, and any cutting insert having a rectangular flat plate shape such as a parallelogram flat plate shape or a rectangular flat plate shape may be used. Moreover, although demonstrated as a cutting insert with which it mounts on what is called a right-handed milling cutter, it is not limited to this, The cutting insert with which a left-handed milling cutter is mounted | worn may be sufficient. In the case of the left hand, the direction of twist is different from that of the present embodiment so that one square surface 2 rotates counterclockwise with respect to the other square surface 2 when viewed from the center line C direction. A twisted cutting insert 1 will be used.

It is a perspective view showing cutting insert 1 of one embodiment of the present invention. It is the top view which looked at one square surface 2 of embodiment shown in FIG. 1 from the centerline C direction. It is a side view of embodiment shown in FIG. It is the bottom view which looked at the other square surface 2 of embodiment shown in FIG. 1 from the centerline C direction. 1 is a perspective view showing an insert detachable rolling tool according to an embodiment of the present invention. FIG. 6 is a side view of the embodiment shown in FIG. 5. FIG. 6 is a bottom view of the embodiment shown in FIG. 5. It is an attachment figure when attaching the cutting insert 1 of embodiment shown in FIG. 1 to the tool main body 11 of the insert detachable type rolling tool of embodiment shown in FIG. It is the attachment figure which looked at FIG. 8 from the other side.

Explanation of symbols

1 Cutting insert 2 Square surface (square surface)
DESCRIPTION OF SYMBOLS 3 Side surface 3A Breaker groove 3B Protrusion part 4 Mounting hole 5 Main cutting edge 5A One end of the main cutting edge 5B The other end of the main cutting edge 6 Sub cutting edge 6A The flank of the sub cutting edge 7 Projection part 8 Chamfer part 9 Display 11 Tool body 12 Insert mounting seat C Centerline of cutting insert 1 O Tool body 11 axis T Tool rotation direction

Claims (6)

  The outer shape is a rectangular flat plate, has two rectangular surfaces and four side surfaces, and the two rectangular surfaces are arranged so as to be twisted around a center line intersecting the rectangular surfaces. A main cutting edge having a rake face on the side surface and a rake face on the side surface is provided on each side ridge portion of the two side surfaces from the one end portion to the other end side. A secondary cutting edge connected to the main cutting edge is formed at one end portion of the one side ridge portion at the intersecting ridge line portion between the side surfaces adjacent to each other, and this one side ridge is formed. On the other end side of the other side ridge part of the quadrangular surface intersecting at one end of the part is convex with respect to the rake face at the other end part of the main cutting edge formed on the other side ridge part. That the flank of the auxiliary cutting edge is formed on the convex. Cutting insert for a butterfly.   The cutting insert according to claim 1, wherein the main cutting edge is formed to have a convex curve shape when viewed from the center line direction.   3. The cutting insert according to claim 1, wherein a chamfer portion that intersects the main cutting edge and the auxiliary cutting edge at an obtuse angle is formed at one end portion of the side ridge portion.   The cutting insert according to any one of claims 1 to 3, wherein a different index is provided at each corner of the rectangular surface.   Breaker grooves are formed along the main cutting edge on the two rectangular surface sides of the side surface, and a protrusion is formed between the breaker grooves. The cutting insert according to any one of claims 1 to 4, wherein is a seating surface.   The cutting insert according to any one of claims 1 to 5 has a tool main body rotated about an axis, and the cutting insert according to any one of claims 1 to 5 is mounted on the mounting seat formed on the outer periphery of the tip of the tool main body. One of the faces is directed to the outer peripheral side of the tool body, the one end of one side ridge of the one square face is projected from the tip of the tool body, and the one side ridge is The formed main cutting edge is detachably attached toward the tool rotation direction side, and the second cutting edge connected to the main cutting edge at the one end of the one side ridge portion is 2 An insert detachable rolling tool characterized in that the other quadrangular surface of the four quadrangular surfaces is positioned on the rear end side in the axial direction.

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