JP4654962B2 - Throwaway tip - Google Patents

Description

  The present invention particularly relates to a throw-away tip (hereinafter referred to as a tip) that is used for copying and has improved chip disposal.

  In profile turning with a cutting tool, the feed direction and cutting of the cutting tool change during machining depending on the shape of the workpiece.Therefore, the chips generated by the cutting edge of the tip attached to the tip of this cutting tool also have its flow direction, width and The thickness also changes sequentially. For example, as shown in FIG. 29, an end face portion (not shown) extending in the direction perpendicular to the axis S via the R portion after an outer diameter portion extending in parallel to the rotation axis S is formed on the outer periphery of the work W as shown in FIG. When the tip T attached to the tip of the chip is to be formed, even if the incision into the surface of the workpiece W is made constant and the thickness of the chips is made equal, the outer diameter portion is around the corner portion C of the chip T. While the cutting blade generates chips with a small width, the end face portion is fed in the direction in which the chip T is pulled up to the outer peripheral side of the workpiece W, so that a certain length of cutting is performed from the corner portion C. Wide chips will be generated using the blade length. Further, in the R portion between the outer diameter portion and the end surface portion, the outflow direction of the chips is remarkably changed, and depending on the shape of the workpiece W before cutting, wide chips are generated also around the corner portion C. There is.

  For this reason, even if a chip breaker for chip disposal is formed on the rake face of the chip T, when a breaker corresponding to a chip having a small width is provided, cutting in the pulling direction of the end face part or cutting of the R part is performed. However, when a wide chip is generated, the chip cannot be reliably processed. On the contrary, if a breaker corresponding to the wide chip is provided, the width generated when the outer diameter portion is cut. As a result, the small chips of the tool extend long without being divided and get entangled with the shank of the cutting tool, resulting in a hindering smooth cutting operation. Further, even when the outflow direction of the chips changes in the processing of the R portion between the outer diameter portion and the end surface portion, it is extremely difficult to reliably process such chips. However, this point, for example, Japanese Patent Application Laid-Open No. 9-38807, has a polygonal plate shape and has a cutting edge and a narrow breaker groove adjacent to the cutting edge on the upper surface ridgeline. A chip in which a substantially hemispherical protrusion is formed in the vicinity of the corner portion on the bisector of the line, and a substantially elliptical protrusion in plan view that is long in the direction parallel to the cutting edge at an equal interval from the corner portion of the apex angle However, in such a chip, the chip is simply separated by flowing out into the rake face along the breaker groove and colliding with each of the above protrusions. If the width of the breaker groove between the elliptical protrusion and the cutting edge is reduced in accordance with the cutting in the pulling direction of the end face part, the outer diameter part is cut high and the feed rate is high. Chip clogging occurred when cutting , A problem that can not follow the direction of flow of chips in the processing of the R portion occurs.

  The present invention has been made under such a background, and an object of the present invention is to provide a chip capable of reliably processing chips generated in the above-described profile turning.

In order to solve the above problems and achieve such an object, the present invention provides a polygonal surface of a chip body having a polygonal flat plate shape, and a polygonal surface on which the raked surface is formed. A chip formed by forming a pair of cutting blades extending from the corners of the polygonal surface at the edge of the surface, and the rake face is inclined so as to be gradually depressed as the distance from the cutting edge increases. The cutting blade is formed with a land along the cutting blade, and the land is inclined so as to be gradually depressed as it is separated from the cutting blade with an inclination angle smaller than the inclination angle of the rake face, and The inclination angle of the rake face and the land is gradually decreased in the direction away from the projecting end of the corner portion, which is the intersection of the bisector of the corner portion, along the cutting edge, and on the rake face. Between the above cutting blades Spaced interval, the two main dots forming a convex spherical at the tip side of the corner portion, it traverses the corner portion in the direction orthogonal to the bisector in a plan view facing the rake face Forming symmetrically with respect to the bisector, and forming at least a pair of sub-dots having a convex spherical shape at positions spaced apart from the main dots along the pair of cutting edges, respectively. the two radius equal to one another in a convex spherical surface main dot forms, and with sub-dots are equal the convex spherical surface which forms the highest point of the height is also the sub dots highest point of the main dots in the thickness direction of the chip body On the other hand, the distance between the cutting edge and the main dot and the sub dot adjacent to the cutting edge is the distance between the cutting edge and the intersecting ridge line between the main dot and the sub dot and the rake face. Lord Dot Than the distance between is characterized in that it has increased towards the space between the sub-dots.

  Therefore, in such a tip, first, the land that is connected to the cutting edge to ensure the strength of the cutting edge and the rake face that is connected to the land are inclined so as to be gradually depressed as the distance from the cutting edge increases. Since the corners are made smaller in the direction away from the corner tip along the pair of cutting edges, the land and the rake face are deepest at the corner from the corner tip to the inside of the rake face. Will be formed. For this reason, when turning the outer diameter part or the R part of the workpiece, the small chips generated by the cutting edge on the projecting side of the corner part are guided in a valley shape formed by the land and the rake face. It flows out along the bottom of the valley and is caused to collide with the convex spherical surface of the main dot formed on the rake face on the corner tip end side to be curled and divided.

  On the other hand, wide chips generated when turning in the direction of pulling up the end face of the workpiece have resistances of different sizes in the width direction because the inclination angles of the land and rake face are gradually reduced along the cutting edge. And is curved and is allowed to flow out in a state in which it is easily divided in the longitudinal direction, that is, the outflow direction. Such chips are caused to collide with a main dot provided on the corner tip end side on the rake face and a sub-dot provided at a position away from the main dot, and receive resistance in the outflow direction. By being curled, the chips are easily divided and processed. Moreover, since these main dots and sub-dots are spherical, even if the chip discharge direction changes, they can collide with the chips by point contact, and stable chip treatment from the outer diameter part to the R part and the end face part. It becomes possible to plan. In addition, the said subdot should just be provided at least 1 each with respect to one corner, ie, at least 1 pair with respect to one corner, About one cutting blade when the cutting blade length to be used is long A plurality of sub dots may be provided at intervals.

Then, two main dots are formed on the tip side of the corner portion on the rake face so as to be arranged in a direction crossing the corner portion, and the radii of the convex spherical surfaces formed by these main dots are equal to each other, and the sub dots together but to equal the eggplant convex spherical surface, since the height of the highest point of the main dots in the thickness direction of the chip body is also equal to the height of the highest point of the sub-dot width by cutting corners tip side When a small chip is generated, the chip flows along the bottom of the valley formed by the land and the rake face, and is guided between the valleys of the two main dots arranged in the direction crossing the corner portion. Of the two main dots, the main dot on the cutting edge side used for use and the sub-dock on the same cutting edge side are used even when wide chips are generated while colliding with one or both of these main dots. Since chips are caused to collide with bets, either it is possible to reliably chip control even when the.

Incidentally, the radius of the convex spherical surface sub dots eggplants, being in the range of 3.0 to 6.5% of the diameter of the circle inscribed in the polygonal surface which the rake face is formed is preferable. This is because, if the radius of the convex sphere formed by this sub-dot is too large, the radius of the main dot also increases and the distance between the corner tip and the main dot becomes too large, as well as the sub-dot surface rising from the rake face. The inclination angle of the chip becomes smaller and the braking effect on the chips becomes weaker, and there is a possibility that the chips will be stretched at a low feed rate. On the other hand, when the cutting depth is high, the contact area with the chips may be increased and the cutting resistance may be increased. This is because, on the contrary, if this radius is too small, it may be worn out at an early stage and the chip life may be shortened. Further, the center position of the convex spherical surface formed by the first sub-dot from the protruding end of the corner portion is along the cutting edge adjacent to the sub-dot from the protruding end of the corner portion in plan view facing the rake face. It is desirable that the first sub-dot be separated from the first surface by a distance of 15 to 40% of the diameter of the circle inscribed in the polygonal surface on which the rake face is formed. When the wide chip is generated, the chip does not reach the sub-dot. Conversely, if the first sub-dot is closer to the corner edge, that is, the main dot, the wide When the chips are generated, only the corner portion side of the chips collides with the main dot and the sub dot, and there is a possibility that reliable processing is hindered in both cases.

Further , on the rake face, a ridge-shaped breaker extending from the main dot to the inside of the rake face in a plan view facing the rake face is formed, and the height of the breaker in the thickness direction of the chip body is formed. Is made higher than the height of the highest point of the main dot and the sub dot, the chips that collide with the main dot and the sub dot and get over the main dot and the sub dot are further collided with the breaker, thereby further reliably processing. can do. When the breaker is formed in this manner, the breaker wall surface extending from the top of the breaker to the rake face in the thickness direction of the chip body protrudes toward the outside of the rake face on the way to the rake face. For example, depending on the angle of intersection of the pair of cutting edges in the corner portion of the rake face, that is, the corner angle, the gap between the breaker wall surface and the cutting edge may be widened. The chip can collide with the stepped portion to ensure the reliable processing. In addition, in order to reliably guide the chips toward the main dots by the valleys formed by the lands and the rake face while ensuring the cutting edge strength of the cutting edges by the lands, the inclination angle of the lands is the corner portion. And a range of 12 ° or less at the center position of the sub-dot adjacent to the main dot, and the difference between the rake face inclination angle and the land inclination angle. Is preferably in the range of 10 to 20 °.

  As described above, in the present invention, when a chip with a small width is generated on the corner tip end side of the cutting edge, the chip is guided and flows out by a valley formed by the land and the rake face, and on the rake face. It is caused to collide with a main dot having a convex spherical shape formed on the corner projecting end side. On the other hand, even when wide chips are generated using a certain cutting edge length from the corner tip, the inclination angle between the land and the rake face is reduced toward the direction in which the cutting edge extends from the corner tip. By being, the chips are generated in the width direction so as to be easily divided in the outflow direction, and both ends in the width direction of such chips collide with the main dots and the sub dots and are curled in the outflow direction. This can be easily divided. Therefore, according to the present invention, reliable chip disposal can be achieved regardless of the width of the chip and the outflow direction thereof, and therefore, it is particularly used for the copying turning process in which the width and outflow direction of the chip sequentially change. Thus, high chip disposal can be achieved, and it becomes possible to achieve smooth and stable machining by preventing entanglement of chips and increase of cutting resistance.

1 to 6 show a reference example for explaining the embodiment of the present invention. In this reference example , the chip body 1 is formed in a substantially rhombic polygonal flat plate shape by a hard material such as cemented carbide, and the rake face 2 is formed on the polygonal surface, that is, the peripheral portion of the rhombus surface. The peripheral surface of the chip body 1 is a flank 3, and a pair of ridges extending on the side ridges of the rhombus surface where the rake surface 2 and the flank 3 intersect are intersected with the corner portion C of the rhombus surface. A cutting edge 4 is formed. Here, the chip body 1 of the present reference example has a symmetrical shape with respect to the rhombus surface on which the rake face 2 is formed, and in the thickness direction of the chip body 1 through the center of these rhombus surfaces. Each of the four side ridges of each of the rhombus surfaces also has four corners in the same shape with respect to a plane including the extending chip center line O and the bisector of each corner C. A pair of cutting blades 4 are formed so as to intersect each of the parts C ..., so that a total of eight pairs of cutting blades 4 are formed on one chip body 1 in front and back. In the tip of this reference example, the corner portion C forming the acute angle of the rhomboid surface has an angle of 80 °, and the flank 3 is parallel to the tip center line O so that no flank is attached. It is a chip.

Further, in a plan view facing the rake face 2 along the chip center line O, each corner portion C... Is formed in an arc shape, and the cutting blades 4... Are smoothly in contact with the corner portion C. Further, those formed on the same side ridge portion are formed so as to be connected in a straight line, and the cutting blades 4 including the corner portion C are positioned on a plane orthogonal to the chip center line O on each of the front and back sides. ing. Further, a mounting hole 5 having a circular cross section centering on the chip center line O is provided between the central portions of the front and back rhombus surfaces, and the periphery of the opening of the mounting hole 5 is as shown in FIG. Further, a flat surface 6 that protrudes from the cutting edge 4 and is highest in the thickness direction of the chip body 1 is formed in a direction perpendicular to the chip centerline O in each rhombus surface, and the chip of this reference example is When the cutting blade 4 on one rhombus surface side is used for cutting, the flat surface 6 of the other rhombus surface is seated in close contact with the bottom surface of the tip mounting seat of the throw-away tool, and then the mounting hole The clamp screw inserted through the screw 5 is screwed into the bottom surface of the mounting seat so as to be detachably attached to the cutting tool. Therefore, the thickness direction of the chip body 1 in the present reference example is a direction perpendicular to the flat surfaces 6 and 6, and the height in the thickness direction is, for example, one of the above-mentioned ones where the cutting edge 4 is used for cutting. On the rhombus surface side, the height is in the direction from the flat surface 6 of the other rhombus surface (polygonal surface) in close contact with the bottom surface of the chip mounting seat to the one rhombus surface side perpendicular to the flat surface 6. In addition, this flat surface 6 is formed so as to protrude in a mountain shape in which the peak is depressed from the opening of the mounting hole 5 toward the midpoint of each side ridge of the rhombus in the plan view.

Here, the rake face 2 is inclined so as to be gradually recessed as it moves away from the cutting edge 4 and toward the inside of the rake face 2 as shown in FIGS. 4 to 6. Is given a positive rake angle. Further, the cutting blade 4 has a land 7 formed along the cutting blade 4, and the land 7 is also inclined so as to be gradually recessed as it moves away from the cutting blade 4 and goes to the inside of the rake face 2. It has been. Further, the inclination angle α formed by the depression-inclined land 7 is set to be smaller than the inclination angle β formed by the rake face 2 that is also inclined-inclined in any part of the cutting edge 4. The land 7 and the rake face 2 are formed in a direction crossing an obtuse angle. Thus, both of these inclination angles α and β in the cross section orthogonal to the cutting edge 4 are the tip of the corner portion C, that is, the corner portion C having an arc shape in the plan view and the bisector of the corner portion C. As the distance from the crossing point increases along the pair of cutting edges 4 and 4 intersecting the corner portion C, it gradually decreases. Note that, in the present reference example , the width of the land 7 in the above-described plan view is substantially equal over the entire circumference of the rhombus surface. However, for example, the width is increased in a direction away from the corner portion C. May be.

Therefore, by changing the inclination angles α and β of the land 7 and the rake face 2 in this way, the land 7 and the rake face 2 have the largest inclination toward the inside of the rake face 2 on the bisector. Inclined at angles α and β and deeply depressed, and formed so that the depression gradually becomes shallower from the bisector along the cutting edges 4 and 4, that is, the bisector is raked In this case, a valley shape that is the bottom of the valley where the depth becomes the deepest toward the inside of 2 is exhibited. Incidentally, in this reference example , the inclination angle α of the land 7 on the bisector at the corner C protrusion is set to 10 °, and the inclination angle β of the rake face 2 is set to 27 °. The inclination angle α of the land 7 on the cross section perpendicular to the cutting edge 4 at both ends of C is set to 8 °, and the inclination angle β of the rake face 2 is set to 25 °. When the inclination angles α and β are changed in this way, the surface 2 that is not easily land 7 may have a twisted surface shape in which the inclination angles α and β are continuously changed. It may be a multistage surface that changes stepwise.

  And in each corner part C, on the rake face 2 inclined in this way, the main dot 8 is formed on the protruding end side of the corner part C, and the pair of cutting blades 4 extending from the protruding end of the corner part C. , 4, a pair of sub-dots 9, 9 are formed at positions spaced apart from the main dot 8 respectively. Since the chip body 1 is formed symmetrically with respect to the bisector of the corner portion C, the main dots 8 and the subdots 9 and 9 are also formed symmetrically with respect to the bisector. It will be. Here, each of the main dots 8 and the sub-dots 9 is projected on the rake face 2 so that the surface thereof has a convex spherical shape, but the protruding height from the rake face 2 is The radius is made sufficiently smaller than the radius of the spherical surface formed by the main dots 8 and the sub-dots 9, and the surfaces of the main dots 8 and the sub-dots 9 and the rake face 2 are made to intersect at an obtuse angle. Further, the sub-dots 9 and 9 formed at positions separated from the main dot 8 are formed such that the surfaces thereof are spaced from each other without overlapping the main dot 8, whereby the main dots 8 and the sub-dots 9 are formed. , 9, the rake face 2 is left.

Here, in the present reference example , one main dot 8 is arranged on the corner portion C protruding end side of the rake face 2 so that the center of the convex spherical surface is located on the bisector in the plan view. Yes. Accordingly, the main dot 8 and the sub-dots 9 and 9 are arranged on the vertices of an isosceles triangle in which the bisector of the corner portion C is an isosceles equisegment. In addition, the radius R of the convex spherical surface formed by the main dots 8 is larger than the radius r of the convex spherical surface formed by the sub-dots 9. Incidentally, in this reference example , the diameter d of the circle inscribed in the rhomboid surface of the chip body 1 on which the rake face 2 is formed is 12.7 mm, and the radius r of the convex spherical surface formed by the sub-dot 9 is 0.1. Accordingly, the radius r of the sub-dot 9 is 4.7% of the inscribed circle diameter d with respect to the inscribed circle diameter d, whereas the radius R of the convex spherical surface formed by the main dot 8 is 2 mm. The size is about 15.7% for d and about 3.3 times the radius r of the sub-dot 9. Further, the height of the highest point of the main dot 8 in the thickness direction of the chip body 1, that is, the surface of the convex spherical surface formed by the main dot 8 and the center of the convex spherical surface formed by the main dot 8 pass through the chip. The height in the thickness direction of the chip body 1 at the intersection with the straight line parallel to the center line O is slightly higher than the height of the highest point of the sub-dots 9, and is substantially lower than the cutting edge 4. It is designed to be the same height or slightly higher.

Further, the position of the center of the convex spherical surface formed by the sub-dot 9 is linearly adjacent to the sub-dot 9 from the protruding end of the corner portion C in the plan view as shown in FIG. In this reference example , the distance L is 3.5 mm. The distance L is in the range of 15 to 40% of the inscribed circle diameter d. And 27.6% of the diameter d of the inscribed circle. Incidentally, in this reference example , in the cross section orthogonal to the cutting edge 4 at the position of the distance L, the inclination angle α of the land 7 is 6 ° and the inclination angle β of the rake face 2 is 22 °. Yes. Further, the distance between the main dots 8 and the sub-dots 9 and the cutting edge 4 is such that the cutting edge 4 and the intersecting ridge line of the main dots 8 and the sub-dots 9 with the rake face 2 extend linearly in the plan view. The distance between the narrowest part between the parts is substantially equal, or the distance between the intersecting ridgeline of the sub-dot 9 with the rake face 2 and the cutting edge 4 is the distance between the intersecting ridgeline of the main dot 8 and the cutting edge 4. The intersection ridgelines are set so as not to overlap the lands 7. The interval in the bisector direction from the corner C protrusion of the cutting edge 4 to the intersection ridge line of the main dot 8 and the rake face 2 is from the cutting edge 4 extending linearly to the intersection ridge line of the main dot 8. It is slightly larger than the interval.

  Furthermore, on the rake face 2, a ridge-shaped breaker 10 is formed so as to extend from the main dot 8 to the inside of the rake face 2 along the bisector in the plan view. The breaker 10 has a top surface in the thickness direction of the chip body 1 as a flat surface 11 having a height equal to the flat surface 6 and perpendicular to the center line O in the thickness direction. The breaker wall surface 12 extending from 11 to the rake surface 12 is an inclined surface that spreads in a skirt shape toward the rake surface 12 side, and the tip of the breaker wall surface 12 on the corner portion C side is inside the rake surface 2 of the main dot 8. The rear end of the opposite wall surface 12 of the breaker wall 12 is connected to the wall surface 13 extending in an inclined manner so as to spread from the flat surface 6 toward the rake face 2 in a skirt shape. It is connected. Accordingly, the height of the breaker 10 in the thickness direction of the chip body 1 is set higher than the height of the highest point of the main dots 8 and sub-dots 9 and the height of the cutting edge 4. Further, the width of the breaker 10 in the direction perpendicular to the bisector in the plan view increases as it goes from the connecting portion with the main dot 8 at the front end toward the rear end as shown in FIG. , Once at a maximum between the pair of sub-dots 9 and 9, and further narrowed so that the breaker wall surface 12 forms a concave curved surface toward the rear end side, and then becomes wide. Are connected to the wall surface 13. A recess 14 that is recessed by one step with respect to the flat surface 11 and the flat surface 6 is formed at a portion where the flat surface 11 of the breaker 10 reaches the opening of the mounting hole 5.

  In the chip configured as described above, the rake face 2 is depressed and inclined as it is separated from the cutting edge 4, and the cutting edge 4 has an inclination angle β of the rake face 2 along the cutting edge 4. In addition, the land 7 is formed so as to be depressed and inclined in a direction away from the cutting edge 4 with a small inclination angle α. Therefore, the edge angle of the cutting edge 4 can be increased to ensure its strength. Since the inclination angles α and β of the land 7 and the rake face 2 are made smaller in the direction away from the protruding end of the corner portion C along the cutting edge 4, the rake face 2 and the land 7 are As described above, a portion from the tip of the corner portion C toward the inside of the rake face 2 exhibits a valley shape having a valley bottom. Since the main dot 8 having a convex spherical shape is formed on the rake face 2 on the corner portion C protruding end side, first in turning the outer diameter portion or the R portion of the workpiece, the corner portion C protruding end side is formed. The small chips generated by the cutting edge 4 are guided along the valley bottom of the valley formed by the land 7 and the rake face 2 and are discharged to the inside of the rake face 2, and the main dots 8 located in the back thereof. It is guided to be surely collided with the convex spherical surface, curled, and divided.

  On the other hand, in the turning of the end face of the workpiece, when feeding is performed in the direction of lifting the tip to the outer peripheral side of the workpiece, the cutting edge 4 having a certain length from the corner C protruding end to the portion extending linearly is generated. Since the slant angles α and β of the lands 7 and the rake face 2 are reduced in the direction of separating along the cutting edge 4 from the corner C protrusion, the wide chips scrape the lands 7 and the rake face 2. When the corner portion C protruding end side is subjected to resistances of different magnitudes, that is, the corner portion C protruding end side has large inclination angles α and β, the chip itself curves in the width direction. The force acts and the resistance is small. On the other hand, on the side away from the corner C protrusion, the inclination angles α and β are small, so that a large resistance is received and the chips are bent in the width direction by these. Flows out to the inside of the rake face 2 in a state, it collides with the sub-dot 9 of the rake face 2 inside the main dot 8 and the cutting edge 4 side is curled in its outflow direction. Thus, if the chips curved in the width direction are curled by resistance in the longitudinal direction, that is, the outflow direction, an excessive force is generated and the chips are easily divided. Even in the case where is generated, according to the chip having the above configuration, it can be reliably divided and processed.

Also, in profile turning, from the turning process of the outer diameter part of the workpiece to the machining of the end face part through the machining of the R part, or conversely, from the machining of the end face part to the machining of the outer diameter part. Even when the chip flow direction changes sequentially as in the case of continuous transition, the land 7 and the rake face 2 are formed in a valley shape as described above in the chip having the above configuration. When a chip with a small width is generated at the corner C tip, it is guided to the valley bottom portion of the valley and is surely made to collide with the main dot 8, and even when a chip with a large width is generated, this valley And the chips are bent and wound when the inclination angles α and β are reduced along the cutting edge 4, so that the main dots 8 and the sub-dots 9 are surely collided with each other. Can wear. In addition, since the main dots 8 and the sub-dots 9 have a convex spherical shape, the dots 8 and 9 are always caused to collide with the chips by point contact even when the outflow direction of the chips changes in this way. The contact does not change depending on the direction, and therefore, more stable chip disposal can be achieved in the processing between the outer diameter portion and the end surface portion in the copying turning processing. Further, on the rake face 2, a main dot 8 is formed on the protruding end side of the corner portion C, and a pair of sub-seconds are disposed at positions separated from each other along the pair of cutting edges 4, 4 intersecting the corner portion C. Since the dots 9 and 9 are respectively formed, and particularly in this reference example , the chip body 1 has a symmetrical shape with respect to the bisector, so that, for example, in profile turning, from one cutting edge 4 to the other cutting edge 4 Even in the case where the portion used for the transfer is transferred, it is possible to achieve stable chip disposal.

Here, regarding the inclination angles α and β of the lands 7 and the rake face 2 that become smaller in the direction in which the cutting edge 4 extends from the corner C protrusion, in the cross section orthogonal to the cutting edge 4 in this reference example , While the inclination angle α is 10 ° and the inclination angle β is 27 °, the inclination angle α at the center position (position of the distance L) of the sub-dot 9 is 6 ° and the inclination angle β is 22 °. If the inclination angles α and β at the corner C tip are too small, the depth of the above valley shape by the land 7 and the rake face 2 becomes small, and it is impossible to reliably guide the chips having a small width. If this is too large, the cutting edge strength of the cutting edge 4 at the corner C protrusion may become too small, and defects or the like may easily occur. Further, if the inclination angles α and β at the position of the sub-dot 9 are too large, the inclination angles α and β will be larger at the corner C tip, so that defects are likely to occur. When the chips are generated, there is a possibility that the chips are not sufficiently bent in the width direction to be easily divided. Further, if the inclination angle β of the rake face 2 is too small with respect to the inclination angle α of the land 7, the amount of protrusion of the dots becomes small, and the effect of curling chips becomes weak. The rise of the main dots 8 and the sub-dots 9 to the surface becomes too steep and the resistance when the chips collide may become too large. For this reason, the inclination angle α of the land 7 is in the range of 2 to 15 ° at the tip of the corner portion C, and is in the range of 12 ° or less at the center position of the sub-dot 9, and the inclination of the rake face 2 It is desirable that the angle β be in the range of 10 to 20 ° with respect to the inclination angle α of the land 7 at each of these positions.

  In addition, the inclination angle α of the land 7 and the inclination angle β of the rake face 2 are made to gradually decrease gradually from the protruding end of the corner portion C toward the direction in which the pair of cutting edges 4 and 4 extend. It may be a constant inclination angle α, β in a predetermined range, and may be a constant inclination angle α, β smaller in the following predetermined range in the above direction. In combination, the predetermined inclination ranges α and β may be equal to each other, and in other predetermined ranges, the inclination angles α and β may be gradually decreased toward the above direction. In this case, the inclination angle α and the inclination angle β may be constant within a predetermined range different from each other, or may be gradually decreased in the above direction. Further, a portion where the land 7 and the rake face 2 intersect may be smoothly connected by a convex curve such as an arc in a cross section perpendicular to the cutting edge 4, and at least the rake face 2 may be It may be formed so as to form a concave curve shape that is gently recessed in the cross section. Furthermore, the land 7 connected to the pair of cutting edges 4 and 4 extending from the corner C and the valley bottom portion of the valley where the rake face 2 intersects each other have a V-shaped cross section perpendicular to the bisector. The portion on the bisector may be formed in a concave curved surface shape.

On the other hand, in the present embodiment, the main dots 8 are formed only one on the rake face 2 of the corner portion C tip side, the radius R of the convex spherical surface the main dot 8 forms than the radius r of the sub-dot 9 And the height of the highest point in the thickness direction of the chip body 1 is also made higher than that of the sub-dots 9. Therefore, even when chips having a small width are generated and flow out along the bottom of the valley formed by the land 7 and the rake face 2, the main dot 8 has a large radius R and a high maximum point. Chips can be reliably collided and curled and divided. Even when wide chips are generated, the radius R of the main dot 8 is increased, so that the surface on the side where the cutting edge 4 of the main dot 8 extends linearly is brought close to the cutting edge 4. The wide chips generated by curving in the width direction as described above can be caused to collide with the main dots 8 and the sub-dots 9 to curl in the outflow direction, Can be divided and processed. In addition, in this reference example , the distance between the linearly extending cutting edge 4 portion and the main dot 8 and the sub dot 9 is substantially equal, or the distance between the sub dot 9 is slightly reduced. The both ends in the width direction of the wide chip can collide with the main dot 8 and the sub dot 9 at substantially the same time and curl in the outflow direction, and the chip is only in one of the main dot 8 and the sub dot 9. It is possible to prevent a situation in which the curling of the chips in the overall outflow direction is hindered by collision.

Note that the radius r of the convex spherical surface formed by the sub-dot 9 having a small diameter with respect to the main dot 8 having a large diameter and a high maximum point is thus formed, and in this reference example , the rake face 2 is formed as described above. The diameter d is 4.7% with respect to the diameter d of the inscribed circle of the polygonal surface (diamond surface). However, if the radius r becomes too large, the sub-dots 9 rising from the rake surface 2 shown in FIG. The inclination angle θ of the convex spherical surface of the surface is reduced, and the braking effect on the chips is weakened, and there is a risk of chip elongation at low feeds, while the circumferential direction of the surface part of the convex spherical surface that contacts the chips at high feeds As a result, the contact length becomes longer and point contact does not occur, which may increase the cutting resistance.
Further, when the radius r of the sub-dot 9 is increased, the radius R of the main dot 8 is also increased accordingly, so that when the wide chip is appropriately curved, it collides with the main dot 8 and the sub-dot 9. If an attempt is made to secure the space between the main dot 8 and the linear cutting blade 4 so as to curl in the outflow direction, the space between the corner C protrusion and the main dot 8 becomes too large, and chips with a small width are generated. When this is done, there is a risk that it will not be able to be processed by quickly colliding with the main dot 8. On the other hand, if the radius r of the sub-dot 9 is too small, the sub-dot 9 may be worn out quickly due to wear when the wide chips collide, and the chip life may be shortened. The radius r of the sub-dot 9 is preferably in the range of 3.0 to 6.5% with respect to the inscribed circle diameter d of the chip body 1.

  On the other hand, if the radius R of the main dot 8 is too large, the rising angle of the main dot 8 becomes small, so that chips with a small width may get over without hitting the main dot 8 sufficiently, but conversely. If it is too small, there is a possibility that the main dot 8 will be worn out at an early stage. Of course, if the center position of the main dot 8 having the radius R reduced in this way is too close to the tip of the corner portion C, the above-mentioned chips are brought into the valley bottom. If the center position of the main dot 8 is the same as when the radius R is large in order to drop the chip into the valley bottom in this way, the cutting edge 4 and the main dot are reduced. Since the rising wall of the convex spherical surface of the surface 8 is separated and the chips are easy to extend at the time of low cutting, the radius R of the main dot 8 is 1 with respect to the inscribed circle diameter d. It is desired to be in the range of to 26%. Further, the difference in height between the highest point in the thickness direction of the chip body 1 between the main dot 8 and the sub dot 9 is too small so that the main dot 8 and the sub dot 9 have substantially the same height. That is, when the height of the main dot 8 becomes relatively low, the small chip generated from the corner C protrusion of the cutting edge 4 gets over the main dot 8 without sufficiently colliding with the main dot 8, and the processing is performed. On the contrary, if the main dot 8 becomes too high, the resistance due to the collision of the chips becomes too great regardless of the width of the chips, and the wear of the main dots 8 is promoted. Since the rotational driving force may increase, the difference in height is preferably in the range of 0.02 to 0.12 mm. Furthermore, if the distance between the center position of the sub-dot 9 and the cutting edge 4, that is, the distance between the center of the convex spherical surface formed by the sub-dot 9 and the cutting edge 4 in the plan view is too large, the main dot 8 is also a rake face. 2, the distance between the main dot 8 and the corner portion C becomes too large. On the other hand, if the distance between the sub-dot 9 and the cutting edge 4 is too small, the end face of the workpiece is pulled up. Since the wide chips generated when turning to the side will collide with the sub-dots 9 and the main dots 8 before being sufficiently curved in the width direction, there is a possibility that even if curled in the outflow direction, it will not be divided reliably. It is desirable that the range is 5 to 12% with respect to the inscribed circle diameter d.

  Further, regarding the position of the sub-dot 9 in the direction in which the cutting edge 4 extends, if this is too far from the corner C protrusion, even if relatively wide chips are generated, out of both ends in the width direction. On the other hand, there is a possibility that the end portion on the side of the sub-dot 9 does not collide with the sub-dot 9. On the contrary, even when the sub-dot 9 is too close to the corner portion C, when wide chips are generated, Only the portion on the corner portion C side in the width direction collides with the main dot 8 and the sub-dot 9, and in each case, the chips come into contact with each other, and the lands 7 and the rake face 2 make the chips in the width direction. Even if it is bent, there is a possibility that the fragmentation occurs only on the side where it comes into contact and the chips remain connected on the opposite side. For this reason, the position L of the sub-dot 9 in the above-mentioned direction, that is, the distance L from the corner C tip in the direction along the linear cutting edge 4 in the plan view to the center of the sub-dot 9 is the diameter of the inscribed circle. It is desirable to arrange in 15 to 40% of d.

In this reference example , one pair of sub-dots 9 and 9 is provided in each corner portion C for each of the pair of cutting blades 4 and 4 intersecting the corner portion C. When the length of the cutting blade 4 used as in the case is long, a plurality of pairs of sub-dots may be provided for each cutting blade at intervals in the above direction. In this case, the distance L is a distance from the corner portion C protruding end to the first sub dot 9. Further, in the case of the diamond-shaped flat chip as in this reference example , when this is used for the above-mentioned profile turning, the cutting edge 4 that intersects the corner portion C that forms an acute angle of the diamond exclusively as shown in FIG. , 4 is used, in such a chip, it is only necessary that the distance L is within the above range at least at the acute corner portion C as shown in FIG.

Furthermore, in this reference example , a ridge-shaped breaker 10 extending from the main dot 8 to the inside of the rake face 2 is formed on the rake face 2, and the height of the breaker 10 in the thickness direction of the chip body 1 is increased. That is, the height of the flat surface 11 at the top is made higher than the highest point of the main dot 8 as well as the sub-dot 9. Therefore, even if the chips collide with these main dots 8 and sub-dots 9 and are not sufficiently curled and get over the rake face 2, they are made to collide with this high breaker 10 located on the back side. Therefore, it is possible to more reliably cut and process the chips. Moreover, the width of the breaker 10 in the direction perpendicular to the bisector increases from the connecting portion with the main dot 8 at the front end toward the rear end side, and between the pair of sub-dots 9, 9. And once again, the width is reduced again, and the portions where the crossed ridgelines of the flat surface 11 and the breaker wall surface 12 are pointed are formed inside the main dot 8 and the sub-dots 9 and 9, respectively. Therefore, the chips that have passed over the main dot 8 and the sub-dot 9 are curled in contact with the pointed portions, so that even if the outflow direction of the chips changes, the chip can be surely divided. And an increase in resistance can be suppressed. In addition, in the present reference example , the breaker wall surface 12 is connected to a wall surface 13 inclined in a skirt shape from the flat surface 6, and the flat surface 6 is the rhomboid surface of the chip body 1 on which the rake face 2 is formed. Since it is formed in a chevron that is convex toward the middle point of each side ridge, even if a cutting blade 4 with a length of more than half of this side ridge is used, The end of the chip in the width direction can be caused to collide with the wall surface 13 connected to the top of the chevron.

FIGS. 7 and 8 show modifications of this reference example, and the same reference numerals are assigned to elements common to the reference example, and description thereof is omitted. Among them, in the modification shown in FIG. 7, although the chip body 15 is a flat plate-shaped similarly substantially rhombic as in Reference Example, 55 ° smaller than the angle of the corner portion C first reference example at an acute angle In addition, no main dot or sub-dot is formed on the corner portion side forming an obtuse angle. This is because such a chip uses only the cutting edges 4 and 4 that intersect the corner part C that makes the acute angle, and the cutting edge length of each cutting edge 4 is one side ridge of the rhombus. Therefore, a plurality of pairs of sub-dots 9 may be formed along the cutting edge 4 as described above. Further, in the modification shown in FIG. 8, the chip body 16 has a substantially equilateral triangle, strictly speaking, the lengths of the side ridges are equal, and the corner C having an acute angle and the corner having an obtuse angle are formed. It is formed in a substantially eccentric hexagonal flat plate shape alternately arranged in the circumferential direction, and each cutting edge 4 that forms a pair by intersecting each corner ridge C forming the acute angle. It is said that. Therefore, in this modification, a total of six pairs of cutting blades 4 and 4 that intersect the three corner portions C on the front and back sides can be used.

Next, FIG. 9 to FIG. 14 show an embodiment of the present invention, and FIG. 15 to FIG. 22 show a modification of this embodiment, both of which are the reference examples shown in FIG. 1 to FIG. Elements that are the same as those in FIG. Among these variations, the angle 55 ° rhombic flat plate Reference Example Modification Like the chip body 15 is corner C of that shown in Figure 7 show, respectively in FIGS. 15 and 17 to 19 FIG. 16 shows a chip body 16 formed in a substantially eccentric hexagonal flat plate shape as in the reference example shown in FIG. 20 shows that the chip body 17 is formed in a substantially square flat plate shape, and FIG. 21 shows that the chip body 18 is formed in a flat plate shape of a substantially equilateral triangle with a straight edge. FIG. 2 shows a modification in which the chip body 19 is formed in a rhombus plate shape in which the corner portion C forming an acute angle is further sharpened to 35 °.

Thus, in the above reference example and its modification, one main dot 8 is formed on the corner portion C protruding end side of the rake face 2, whereas in these embodiments and its modifications, the rake face 2 is formed. Two main dots 21 and 21 are formed on the protruding end side of the upper corner portion C so as to be aligned in a direction crossing the corner portion C. Here, these two main dots 21 and 21 are arranged so as to be symmetrical with respect to the bisector in the direction perpendicular to the bisector of the corner portion C in the plan view. However, the intersection ridgelines of the main dots 21 and 21 and the rake face 2 are separated so as not to overlap each other except for the modification shown in FIG. 22, and the tip of the breaker 10 is inclined. The breaker wall surface 12 intersects the rake face 2 on the bisector between the main dots 21 and 21.

The main dots 21 and 21 have a convex spherical shape that protrudes from the rake face 2 with a protrusion height smaller than the radius, similar to the main dot 8, but the main dots 21 and 21 form the main dots 21 and 21. The radius of the convex spherical surface is made equal to the radius r of the sub-dot 9, and the radii of both the main dots 21 and 21 are also made equal to each other. Further, these main dots 21, 21, while being high even equal the highest point in the thickness direction of the chip body 1, there is a height equal height of the highest point of the sub-dot 9,9 Tomoko . In this embodiment and its modification, the radius r of the sub-dot 9 is set to 3.0 to 6.5% of the diameter d of the inscribed circle. Therefore, the radius of the main dot 21 is also 3 of the diameter d. The distance L from the corner C protrusion to the center of the secondary dot 9 in the direction along the cutting edge 4 extending linearly is 15 to 40% of the inscribed circle diameter d. It is considered as a range. Further, the interval between the linearly extending cutting edge 4 portion and the main dot 21 and the sub dot 9 adjacent thereto is defined by the intersection ridgeline between the main dot 21 and the sub dot 9 and the rake face 2 and the cutting edge 4. The intervals are substantially equal to each other or, as opposed to the above reference example, as shown in FIG. 10, FIG. 15, FIG. 16, FIG. 18, or FIG. The distance from 9 is slightly larger.

Therefore, even in the embodiment configured as described above and the tip of the modified example thereof, when wide chips are generated using the portion extending from the corner C protruding end of the cutting edge 4 to the linear shape, Since the slopes α and β of the land 7 and the rake face 2 connected to the cutting edge 4 are reduced in the direction in which the cutting edge 4 extends from the corner C protrusion, the chips are curved in the width direction. It is made to flow out in a state that is easily divided. Then, on the rake face 2 at the back of the linearly extending cutting edge 4 portion, the sub-dot 9 adjacent to the cutting edge 4 of the pair of sub-dots 9, 9 and the two main dots 21, The main dots 21 that are also adjacent to the cutting blades 4 are provided in the direction in which the cutting blades 4 extend, that is, in the width direction of the chips, and the main dots 21 and the sub-dots 9 are separated from each other. since the height of the highest point is equal in the radial and the thickness direction, the chips by both widthwise ends of the chip is substantially uniformly collide with the subsidiary dots 9 with these main dots 21 in the outflow direction Since it is curled by receiving resistance and is easily divided as described above, it can be easily processed.

On the other hand, in the present embodiment and its modification, the two main dots 21 and 21 on the corner portion C protruding end side of the rake face 2 are orthogonal to the bisector in a plan view facing the rake face. by being formed in parallel symmetrically with respect to the bisector I traverse the corner portion C, the the back of the valley-shaped formed by the lands 7 and the rake face 2, these main dot 21 , 21 stand up across the valley bottom portion of the valley shape, and accordingly, when chips with a small width are generated by the cutting edge 4 on the corner portion C protruding end side, along the valley bottom of the valley shape. The chips that have flown out are collided with one or both of the two peaks in the back from the bottom of the valley, curled, and divided. In addition, in this case, the distance from the corner C protrusion of the cutting edge 4 to the main dots 21 and 21, that is, the distance to the intersecting ridge line between the main dots 21 and 21 and the rake face 2 is, for example, as in the above reference example. Compared with the case where one ridge having a large radius R and a high maximum point is provided on the rake face 2, it becomes larger as can be seen by comparing FIG. 2 and FIG. When the rake face 2 is deeply inclined and tilted, the main dots 21 and 21 having a small radius and thus a large curvature will stand up. Can be made. For this reason, even when chips with such a small width are generated, it is excellent when chips that are thin and tend to stretch easily are generated, especially in the case of low cutting and low feed. It is possible to obtain a chip disposal property.

Also in such embodiments and modifications thereof, when the radius r of the convex spherical surface sub dots 9 forms are too large, or larger cutting resistance during high-feed with elongation chips at low feed occurs, Further, since the radius of the main dot 21 which is substantially the same radius as the sub-dot 9 is also increased, if two such main dots 21 are arranged on the rake face 2 in a direction crossing the corner portion C, the main dot 21 is formed. The distance between 21 and 21 and the corner portion C tip becomes too large, so that chips flow out on the rake face 2 more than necessary before colliding with the main dots 21 and 21, and the main dot is surely There is a risk that it may be difficult to make the 21 and 21 collide. On the other hand, if the radius r of the sub-dot 9 is too small, the sub-dot 9 is worn out early as in the first embodiment, and the main dots 21 and 21 are also worn out early. Therefore, it is desirable that the radius r of the sub-dot 9 is 3.0 to 6.5% of the inscribed circle radius d. Therefore, in this embodiment , the radius of the convex spherical surface formed by the main dots 21 is also 3.0 to 6.5% with respect to the diameter d of the circle inscribed in the polygonal surface of the chip body 1 on which the rake face 2 is formed. It is desirable to be within the range.

  In addition, the distance L from the tip of the corner C to the center position of the sub-dot 9 is too large, and when the sub-dot 9 is too far from the main dot 21, a wide chip is generated. While there is a possibility that only one end portion in the width direction is caused to collide with the main dot 21, conversely, even if the distance L is too small and the sub dot 9 is too close to the main dot 21, the one end portion of the wide chip is again. Since only the main dot 21 and the sub dot 9 are caused to collide with each other, the chips come into contact with each other, so that there is a possibility that it cannot be reliably curled in the outflow direction and divided. Therefore, it is desirable that the distance L is in the range of 15 to 40% with respect to the inscribed circle diameter d.

  By the way, as in the modification shown in FIG. 7 and FIG. 15, the chip body 15 is formed in a rhombus flat plate shape having an acute angle of the corner portion C of 55 °, or a rhombus flat plate shape of 60 °. In such a case, the width of the breaker 10 in the direction perpendicular to the bisector of the corner portion C increases from the connecting portion with the main dot 8 toward the rear end portion side as described above. In other words, once the maximum value is reached between the pair of sub-dots 9, 9, the sub-dot 9 is formed along the cutting edge 4 as shown in FIGS. 7 and 15. In the portion where the width of the breaker 10 on the side opposite to the corner portion C is narrow, the gap between the cutting edge 4 and the breaker wall surface 12 is widened, and is generated by the cutting edge 4 of that portion. There is a risk that the chips will stretch is there. However, in such a case, as described above, the sub-dots 9 may be provided in the portion where there is a gap as described above, but other than this, for example, as shown in the modified examples shown in FIGS. Further, the breaker wall surface 12 of the breaker 10 protrudes from the breaker wall surface 12 toward the outside of the rake face 2, that is, toward the cutting edge 4 in the middle of the breaker wall face 12 from the top 11 to the rake face 2. You may make it form the level | step-difference part 22 which becomes.

  Here, the step portion 22 includes a flat surface 23 parallel to the flat surface 11 at the top of the breaker 10 and lowered in the thickness direction, and a rake face 12 having an inclination substantially equal to the breaker wall surface 12 from the flat surface 23. And the wall surface 24 has a stepped shape that is one step down from the flat surface 11 of the breaker 10, and the wall surface 24 starts from the vicinity where the width of the breaker 10 starts to become narrower. It is formed so as to extend straightly in parallel with the cutting edge 4 and reach the wall surface 13 in a plan view facing the rake face 2 along O. Therefore, according to the chip of the modified example in which such a stepped portion 22 is provided on the breaker wall surface 12, the sub-dot 9 is not provided at a portion where the distance between the breaker wall surface 12 and the cutting edge 4 is large. However, the chips generated by the cutting edge 4 can be curled by pressing against the wall surface 24 of the stepped portion 22 and the intersecting ridge line portion between the wall surface 24 and the flat surface 23 so that the chips are stretched. Smooth processing can be achieved by preventing the illness.

  1 and FIG. 10, even when the chip body 1 has a rhomboid plate shape, the corner portion C forming an acute angle has a large angle of 85 °, or the chip body 17 has a square plate shape as shown in FIG. If the angle is 90 °, or if the chip bodies 16 and 18 have a substantially equilateral triangular plate shape as shown in FIG. 8, FIG. 16, and FIG. Are formed so that the cutting edges 4 and 4 extend from the corners C and C at both ends thereof, and therefore the cutting edge length of each cutting edge 4 is about half of the one-side ridge. Since the length of the cutting edge 4 on the opposite side of the corner portion C from the sub-dot 9 is shortened, the chips can be removed from the sub-dot 9 and the main dot without providing the step portion 22 as described above. 8, 21 or breaker 10 for reliable processing Can. On the other hand, as shown in FIG. 22, even when the chip body 19 having the same rhomboid plate shape is used, Since the large gap between the breaker 10 and the breaker 10 is not originally provided, the stepped portion 22 is formed of a diamond-shaped flat chip body in which the angle of the corner portion C is about 55 ° or 60 ° as described above. It is effective to be provided in the chip having.

Here, FIG. 23 is fed by the tip of the reference example shown in FIGS. 1 to 6 described above, and FIGS. 24 and 25 are the tips of the first and second comparative examples. First, as shown in FIG. 26, the end surface portion P perpendicular to the rotation axis of the workpiece W, the outer diameter portion Q extending in parallel with the rotation axis, and these end surface portions P are set to 0.1 to 0.2 mm / rev and the cut is 1 mm. 2 shows the state of the chips when the chamfered portion M is formed at the portion where the outer diameter portion Q intersects with the outer diameter portion Q. It is chips generated by cutting the diameter portion Q and the chamfered portion M. However, in FIG. 23, the chips of the end surface portion P and the chamfered portion M are shown together. In addition, the material of the workpiece | work W at this time was S45C material, the cutting speed was 170 m / min, and was wet cutting. Here, in the chips of the first and second comparative examples, both the land inclination angle is 6 ° and the rake face inclination angle is 22 °, which are constant over the entire circumference of the rake face. Of these, the sub-dot 9 is not formed on the chip of the first comparative example in which the chips of FIG. 24 are generated, while the radius of the chip of the second comparative example in which the chips of FIG. A sub-dot having a large convex spherical shape of 1.5 mm (11.8% of the diameter of the inscribed circle) has a distance L from the corner C protrusion of 3.5 mm (of the inscribed circle) as in the first embodiment. be formed by positioning the center position of the 27.6% of the diameter), the shape of the portions other than these dimensions are the same as the first, with the second comparative example embodiment. However, from these figures, in the chips of Comparative Examples 1 and 2, although the chips are fragmented, some chips with irregularly curled and elongated strips are generated, whereas in the chips of the reference example , It can be seen that chips with excellent curling properties are obtained.

Next, FIG. 27 shows the tip of the reference example as in the above, and FIG. 28 shows the tip of the first comparative example of the two comparative examples. The state of the chip when the R section between the diameter section and the end face section is cut is shown. The feed at this time was 0.25 mm / rev, the cut was 0.8 to 3.5 mm, the work material was equivalent to S50C, and was wet cutting. As a result, as shown in these FIGS. 27 and 28, the chip of the first comparative example can not be separated chips, but its length is equal to or more than 30 cm, according to the reference example contrast An excellent chip breaking property was obtained with the chip.

It is a perspective view which shows the reference example of this invention. It is a top view in the chip | tip centerline O direction view of the reference example shown in FIG. FIG. 2 is a side view of the reference example shown in FIG. 1 (a view of the chip body 1 seen from below in FIG. 2). It is XX sectional drawing in FIG. It is YY sectional drawing in FIG. It is ZZ sectional drawing in FIG. It is a top view which shows the modification of a reference example . It is a top view which shows the modification of a reference example . It is a perspective view which shows embodiment of this invention. FIG. 10 is a plan view of the embodiment shown in FIG. 9 as viewed in the direction of the chip center line O. FIG. 10 is a side view of the embodiment shown in FIG. 9 (a view of the chip body 1 viewed from below in FIG. 10). It is XX sectional drawing in FIG. It is YY sectional drawing in FIG. It is ZZ sectional drawing in FIG. It is a top view which shows the modification of embodiment . It is a top view which shows the modification of embodiment . It is a perspective view which shows the modification of embodiment . It is a top view of the modification shown in FIG. It is ZZ sectional drawing in FIG. It is a top view which shows the modification of embodiment . It is a top view which shows the modification of embodiment . It is a top view which shows the modification of embodiment . It is a figure which shows the chip at the time of cutting of the end surface part P of the workpiece | work W by the reference example , the outer diameter part Q, and the chamfering part M. It is a figure which shows the chip at the time of the cutting | disconnection of the end surface part P of the workpiece | work W by the 1st comparative example, the outer diameter part Q, and the chamfering part M. It is a figure which shows the chip at the time of the cutting | disconnection of the end surface part P of the workpiece | work W by the 2nd comparative example, the outer diameter part Q, and the chamfering part M. It is a figure which shows the cutting by the Example shown in FIG. 23 thru | or FIG. It is a figure which shows the chip at the time of the cutting of the R part of the workpiece | work W by a reference example . It is a figure which shows the chip at the time of the cutting of the R part of the workpiece | work W by a 1st comparative example. It is a figure which shows an example of a profile turning process.

1,15,16,17,18,19 Chip body 2 Rake face 4 Cutting edge 7 Land 8, 21 Main dot 9 Sub dot 10 Breaker 12 Breaker wall 22 Stepped portion α Inclination angle of land 7 Inclination angle of rake face 2 C Corner portion L Distance from the tip of the corner portion C to the center position of the convex spherical surface formed by the sub-dot 9 r The radius of the convex spherical surface formed by the sub-dot 9 R The radius of the convex spherical surface formed by the main dot 8 d The rake face 2 is formed Diameter of the circle inscribed in the polygonal surface

Claims (4)

A rake face is formed on the polygonal surface of the chip body having a polygonal flat plate shape, and a pair of edges extending on the side ridges of the polygonal surface on which the rake face is formed intersecting the corner part of the polygonal surface. The rake face is inclined so as to be gradually depressed as it is separated from the cutting edge, and a land is formed on the cutting edge along the cutting edge. The lands are inclined so as to gradually sink as they are separated from the cutting edge at an inclination angle smaller than the inclination angle of the rake face, and the inclination angles of the rake face and the land are It is made to gradually become smaller in the direction of separating along the cutting edge from the protruding end of the corner portion, which is the intersection with the bisector, and is spaced from the cutting edge on the rake face. The above corner section Two main dots at the tip side forms a convex spherical shape, symmetry in a plan view facing the rake face I traverse the corner portion in the direction orthogonal to the bisector with respect to the bisector And at least a pair of sub-dots having a convex spherical shape are formed at positions spaced apart from the main dots along the pair of cutting edges, respectively, and the two main dots are Nasu radius of the convex spherical surface are equal to each other, and together are equal the convex spherical surface about the sub dots formed, the height of the highest point of the main dots in the thickness direction of the chip body also equal to the height of the highest point of the sub-dot On the other hand, the interval between the cutting edge and the main dot and sub dot adjacent to the cutting edge is defined as the distance between the cutting edge and the intersecting ridge line between the main dot and sub dot and the rake face. When Indexable insert, characterized in that towards the space between the sub dots are larger than the distance. Claim radius of the convex spherical surface the sub dots formed, characterized in that there is a range of 3.0 to 6.5% of the diameter of the circle inscribed in the polygonal surface which the rake face is formed 1 The throw-away chip as described in. The position of the center of the convex spherical surface formed by the first sub dot from the tip of the corner portion is along the cutting edge adjacent to the sub dot from the tip of the corner portion in a plan view facing the rake face. 3. The method according to claim 1 , wherein the rake face is disposed within a distance range of 15 to 40% of a diameter of a circle inscribed in a polygonal face on which the rake face is formed. The throw-away tip described. The inclination angle of the land is in the range of 2 to 15 ° at the tip of the corner portion, and is 12 ° or less at the center position of the sub dot adjacent to the main dot, and the inclination angle of the rake face is The throw-away tip according to any one of claims 1 to 3 , wherein a difference from an inclination angle of the land is within a range of 10 to 20 °.

Images