JP2007050477A - Drill with extra-high pressure sintered body chip - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a drill with an extra-high pressure sintered body chip being the drill constituted by arranging the extra-high pressure sintered body chip in a cutting blade part, capable of cutting a chip into pieces over the whole length of the cutting blade even in the direction of length securely while cutting the chip into pieces in the direction of its width by providing the cutting blade with nicks. <P>SOLUTION: A plurality of cutting blades 9 extending from the outer periphery of a tip of a drill main body 1 toward an inner peripheral side are formed at an interval in the peripheral direction on the extra-high pressure sintered body chip 8 arranged in a tip part of the drill main body 1 rotated around an axis 0. The recessed groove-like nicks 10 are formed on these cutting blades 9 so as to deviate rotation locus around the axis 0 by the cutting blades 9 being adjacent to each other in the peripheral direction to apply honing 11 having a narrower width on an outer peripheral side of the cutting blade 9 than the width on an inner peripheral side. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention is used, for example, for drilling a workpiece such as an aluminum material, and an ultra-high pressure sintered chip such as diamond or cBN is disposed at the tip of a drill body, and a cutting blade is formed on the ultra-high pressure sintered chip. The present invention relates to a drill with an ultra-high-pressure sintered body chip formed with the above.

As this type of drill with an ultra-high pressure sintered body tip, the inventors of the present invention, for example, in Patent Documents 1 and 2, etc., of the chip discharge groove formed on the outer periphery of the tip of the drill body rotated around the axis. A tip of an ultra-high pressure sintered body such as a diamond sintered body or a cBN sintered body is disposed by brazing or the like on the outer peripheral side of the tip of the wall facing the drill rotation direction, and a drill is placed on the ultra-high pressure sintered body tip. It has proposed that a cutting blade extending from the outer periphery of the tip of the main body toward the inner peripheral side is formed. According to such a drill with an ultra-high pressure sintered body tip, high strength and wear resistance can be ensured on the cutting edge by the ultra-high-pressure sintered body tip with high hardness.
JP 2003-205413 A JP 2004-50353 A

  By the way, when drilling a workpiece having a complicated shape such as an engine block of an automobile or the like with such a drill, it is easy to discharge chips to the outside of the workpiece in a subsequent process of the drilling. Therefore, it is desirable to divide the chips generated in the drilling process as small as possible. Here, even a cutting tool rotated around the same axis, for example, in an end mill in which a cutting edge extending in the axial direction is formed on the outer periphery of the tool body, as a means for dividing chips in this way, a cutting blade has been conventionally used. Groove-shaped nicks are formed so that they intersect, and the rotation trajectory of the nicks is shifted between the cutting blades adjacent to each other in the rotation direction of the tool body, so that chips are preliminarily divided in the width direction from the nicks. Is known to be generated.

  However, the cutting by the end mill is intermittent cutting, and the chips are generated intermittently in the length direction, whereas the cutting by the drill is continuous cutting in which chips are generated continuously, usually a cutting edge. The curl is curled by the difference in rotational speed (circumferential speed difference) on the inner and outer circumferences (chip width direction) and divided in the length direction. In such a drill, the cutting blade is nicked as described above. Since the chips are generated for each short range between nicks, the circumferential speed difference in the width direction becomes small and extends in a straight shape, and it is difficult to curl the chips sufficiently and divide in the length direction. Become. In particular, the perimeter of the drill body on the outer peripheral side of the cutting blade has a narrower permissible range for such chip separation compared to the inner peripheral side portion, and even in this outer peripheral side portion, from the outermost nick to the outer peripheral edge of the cutting blade. In the cutting blade having a shorter length, the peripheral speed difference in the width direction of the chips is further reduced, so that the cutting in the length direction becomes more difficult.

  Moreover, in the drill having the nick formed on the cutting edge in this way, a protrusion is formed on the bottom of the processed hole cut by the preceding cutting edge in the drill rotation direction by the uncut portion by the nick, and then the nick rotation locus is Since the bottom of the hole is cut along with the ridge by the shifted subsequent cutting blade to generate swarf, the swarf has a T-shaped irregular shape in which the ridge extends in a rib shape in the length direction thereof. Thus, the rib-shaped protrusions make it difficult for the chips to be curled further in the length direction, making it difficult to cut. Such a tendency becomes more prominent as the ratio of the actual chip thickness to the depth of cut, that is, the chip compression ratio, increases the influence of the T-shaped irregular cross section.

  The present invention has been made under such a background, and in a drill in which an ultra-high pressure sintered body chip is disposed at a cutting edge portion, the width of chips is reduced by providing a nick on the cutting edge as described above. An object of the present invention is to provide a drill with an ultra-high pressure sintered body tip that can be reliably cut along the entire length of the cutting blade in the length direction while being cut in the direction.

  In order to solve the above-mentioned problems and achieve such an object, the present invention provides a drill body of the above-described drill body on an ultra-high-pressure sintered body chip disposed at the tip of the drill body rotated about an axis. A plurality of cutting edges extending from the outer periphery of the tip toward the inner periphery are formed at intervals in the circumferential direction, and these cutting edges are recessed so as to shift the rotation trajectory around the axis line between the cutting edges adjacent in the circumferential direction. A groove-shaped nick is formed, and honing which is narrower than the inner peripheral side is performed on the outer peripheral side of the cutting blade.

  In the drill with an ultra-high-pressure sintered body tip configured in this way, the cutting blades formed on the ultra-high-pressure sintered body tip disposed at the tip of the drill body have an axis line between the cutting blades adjacent in the circumferential direction. Nicks are formed so as to shift the rotation trajectory around, and high strength and wear resistance can be imparted to the cutting edge with a high hardness ultra high pressure sintered chip, and in a short range between the nicks Chips can be generated by dividing in the width direction. In addition, the cutting edge is honed by chamfering or rounding the cutting edge, and by applying resistance to the generated chip by this honing, the chip is curled in its length direction. And can be divided.

  However, if the resistance due to honing is too large, the chip compression ratio increases and the influence of the T-shaped irregular cross section increases as described above. In particular, in the outer peripheral side portion of the cutting blade in which the length from the nick on the outermost periphery to the outer peripheral edge of the cutting blade is shortened, there is a possibility that the chip dividing property in the length direction is impaired. Therefore, in the drill with an ultra-high pressure sintered body tip of the present invention, this honing is made narrower on the outer peripheral side of the drill body than on the inner peripheral side so that the chip compression ratio does not become too large. It becomes possible to divide the chips into both the width direction and the length direction with reliability over the entire length of the cutting blade and to make it finer.

  Therefore, according to such a drill with an ultra-high pressure sintered body chip, even when drilling a workpiece having a complicated shape such as an engine block of an automobile or the like, chips can be easily removed in the subsequent process of drilling. Therefore, the workpiece can be discharged to the outside of the workpiece, and the workpiece can be processed smoothly and efficiently. In addition, since the peripheral speed in drilling is reduced, the hole bottom is sharpened and the load is applied to the inner peripheral portion of the cutting blade, which is honed compared to the outer peripheral portion. Since the width becomes large, sufficient fracture resistance can be secured even for such a large load, and while it is high in hardness, it is possible to prevent the occurrence of defects in the ultra-high pressure sintered chip having high brittleness. The advantage is also obtained.

  It should be noted that, in contrast to the inner peripheral side portion of the cutting blade whose fracture resistance is ensured by increasing the honing width in this way, the chip dividing property is also impaired in the outer peripheral side portion where the honing width is reduced as described above. In order to ensure sufficient fracture resistance without any problem, first, this honing is performed as a multi-stage honing that bends toward the tip side of the drill body so that the honing angle increases. What is necessary is just to give a moderate resistance to a chip | tip by the honing of the stage of a rear-end side, ensuring the intensity | strength of the blade edge itself of a cutting blade. Separately or in combination with this, the cutting blade is formed in a multi-stage shape that bends toward the outer peripheral side of the drill body so that the tip angle becomes smaller, and the cutting blade of the generated chips The thickness in a direction orthogonal to the angle may be kept small, or the outer peripheral end of the cutting blade may be formed in a convex curve shape to provide a so-called corner R to ensure its strength.

  1 to 5 show a first embodiment of the present invention. In the present embodiment, the drill body 1 is formed in a substantially cylindrical shape centering on the axis O as shown in FIGS. 1 and 4 with a hard material such as cemented carbide, and the rear end side (the right side in FIG. 1). ) Portion is a shank portion 2, and a tip side (left side in FIG. 1) portion is a cutting edge portion 3, and the shank portion 2 is gripped by a spindle of a machine tool and is rotated in a drill rotation direction T around an axis O. The workpiece is drilled by the cutting edge portion 3 by being sent to the front end side in the axis O direction while being rotated.

  On the outer periphery of the cutting edge portion 3, a plurality of (two in the present embodiment) chip discharge grooves 4 that spirally extend so as to be twisted rearward in the drill rotation direction T from the front end toward the rear end. Are formed symmetrically with respect to the axis O with an interval in the circumferential direction, and the rear end side portions of these chip discharge grooves 4 extend to the front end side portion of the shank portion 2 and are rounded up to the outer peripheral side. Yes. On the other hand, on the tip end side of these chip discharge grooves 4, a wall surface 4A facing the drill rotation direction T side is recessed by one step from the wall surface 4A to the rear side of the drill rotation direction T, and the tip flank 5 and the outer periphery of the drill body 1 are disposed. A recess 7 is formed in the margin 6, and an ultrahigh-pressure sintered body chip 8 made of a diamond sintered body or a cBN sintered body is joined to the recess 7 by brazing or the like. ing.

  Here, in the present embodiment, the concave portion 7 is formed on the front end side of the wall surface 4A of each of the plurality of chip discharge grooves 4 so as to reach the margin portion 6 from a position slightly away from the axis O to the outer peripheral side. These are formed independently of each other, and substantially flat plate-like ultrahigh-pressure sintered chips 8 are disposed in these recesses 7, respectively. Accordingly, the vicinity of the axis O on the inner peripheral side of the tip flank 5 (the center of drill rotation) In the periphery), the drill body 1 made of the hard material is left. And in the intersection ridgeline part of side surface 8A which continues to said wall surface 4A of this ultra-high pressure sintered compact chip 8, and front end surface 8B which continues to said front-end flank 5, from the tip outer periphery of drill body 1 toward the inner peripheral side A cutting blade 9 extending toward the distal end is formed. The cutting blade 9 is formed with a groove-shaped nick 10 and a honing 11 which is narrower on the outer peripheral side than on the inner peripheral side. Yes.

  The nick 10 is formed in a concave groove shape that opens to the side surface 8A and extends perpendicularly to the cutting edge 9 when viewed from the front in the direction of the axis O, and the opening on the side surface 8A of the nick 10 has a groove bottom of the concave groove. The side (the drill body 1 rear end side) is a U-shaped portion 10A, and the cutting blade 9 side (the drill body 1 front end side) is V-shaped with the groove width gradually expanding toward the cutting blade 9 side. Part 10B. Further, as shown in FIG. 4, the nick 10 is formed so that the groove width gradually increases from the cutting edge 9 toward the rear side in the drill rotation direction T as shown in FIG. The body tip 8 is formed so as to reach the tip flank 5 portion of the drill body 1 beyond the tip surface 8B.

  In the present embodiment, such nicks 10 having the same shape and the same size are provided on a plurality of (two in the present embodiment) ultrahigh-pressure sintered body chips 8 disposed at the tips of the plurality of chip discharge grooves 4. A plurality (two in this embodiment) are formed on each of the cutting blades 9, but between the cutting blades 9 of these ultra-high pressure sintered body chips 8, the cutting blades 9 adjacent in the circumferential direction are adjacent to each other. The rotation locus around the axis O is arranged to be shifted. That is, in one cutting blade 9 extending downward from the axis O in FIG. 4, the nicks 10 are formed at two locations that divide the axial line O from the axis O to the outer peripheral end of the cutting blade 9 in approximately three equal parts. On the other hand, in the other cutting blade 9 extending upward from the axis O, the rotation trajectory around the axis O of the two nicks 10 is between the two nicks 10 of the one cutting blade 9 and the outer peripheral side thereof. Between the nick 10 and the outer peripheral edge of the one cutting edge 9. In the present embodiment, the intervals between the nicks 10 in the respective cutting blades 9 are substantially equal between the cutting blades 9, except that the rotation trajectory of the nicks 10 between the cutting blades 9 is unequal in the radial direction. ing.

  On the other hand, in the present embodiment, the honing 11 has a predetermined honing angle θ at the intersection ridge line portion between the side surface 8A and the tip surface 8B of the ultrahigh pressure sintered body chip 8 on which the cutting edge 9 is formed as shown in FIG. The angle W that is chamfered with the cutting edge 9 of the honing 11 has a width W in the cross-section perpendicular to the cutting edge 9 in the direction of the axis O, as shown in FIG. The width is gradually narrowed at a constant rate from the inner peripheral side toward the outer peripheral side along the cutting edge 9. However, the width W of the honing 11 is formed so as to be smaller than the depth of the concave groove formed by the opening in the side surface 8A of the nick 10 over the entire length of the cutting blade 9. In this embodiment, the honing 11 thus divided is gradually narrowed in a taper shape that tapers toward the outer periphery as seen from the direction facing the side surface 8A as shown in FIG. It is supposed to be.

  As described above, the inner periphery of the cutting edge 9 on the ultrahigh-pressure sintered chip 8 is thinned in the vicinity of the axis O on the inner peripheral side of the tip flank 5 where the drill body 1 portion remains. A thinning blade 12 that is continuous with the end and extends further to the inner peripheral side is formed. The thinning blade 12 extends on the extension line of the cutting blade 9 as shown in FIG. 2 in the direction facing the side surface 8A, while the thinning blade 12 in the direction of the axis O direction as shown in FIG. The nick 10 and the honing 11 are not formed on the thinning blade 12 except that the thinning blade 12 is bent and inclined toward the axis O side toward the inner circumference side with respect to the extension line toward the inner circumference side. . Further, the end face 8C on the outer peripheral side of the drill body 1 of the ultra-high pressure sintered body tip 8 is formed on a substantially cylindrical surface centering on the axis O that is flush with the margin portion 6, and in the present embodiment. This drill is a double margin type drill in which a margin portion 13 is also formed on the heel side.

  In the drill with an ultrahigh-pressure sintered body chip configured as described above, an ultrahigh-pressure sintered body chip 8 made of a diamond sintered body or a cBN sintered body is first disposed at the tip of the drill body 1. The cutting edge 9 is formed on the ultra-high pressure sintered chip 8 having a high hardness. Therefore, the cutting edge 9 can be given high strength and wear resistance, and a sharp sharpness can be ensured over a long period of time. be able to. On the other hand, in the present embodiment, the ultrahigh-pressure sintered body tip 8 is not disposed in the vicinity of the axis O on the inner peripheral side of the drill body 1, and the thinning blade 12 is provided on the drill body 1 itself made of cemented carbide or the like. In the vicinity of the axis O, which is formed and is cut so as to crush the workpiece because the peripheral speed is the smallest, an excessive load acts on the ultrahigh-pressure sintered chip 8 to cause chipping or chipping. Can be prevented.

  Further, since the cutting blade 9 is formed with a groove-shaped nick 10 so as to shift the rotation trajectory around the axis O between the cutting blades 9 adjacent to each other in the drill rotation direction T, the chips are separated together with the nick 10. The plurality of cutting blades 9 are alternately divided in the width direction to be generated. However, when chips are generated by being divided in the width direction by the nick 10 in this way, each chip generates a small difference in peripheral speed between the inner and outer circumferences in the width direction, and each chip has a rib-shaped protrusion. It becomes a T-shaped irregular shape and is not curled in the longitudinal direction and is difficult to be divided. On the other hand, since the honing 11 is given to the above-mentioned cutting edge 9, the resistance is applied to each of the chips generated by being divided in the width direction by the nick 10 in this manner, thereby compressing the length. It can be divided by curling in the vertical direction.

  Further, the honing 11 applied to the cutting edge 9 has a width W that is narrower than the inner peripheral side at the cutting blade 9 portion on the outer peripheral side of the drill body 1. The resistance generated by the honing 11 can be prevented from increasing with respect to chips generated by the cutting blade 9 portion. Therefore, the chips generated by the nick 10 as described above in the T-shaped cross section are difficult to be divided when the chip compression ratio by the honing 11 is increased. The tendency becomes remarkable in the blade 9 portion, whereas in the drill with an ultrahigh-pressure sintered body chip having the above-described configuration, the chip compression ratio is prevented from being excessively increased in the outer peripheral side cutting blade 9 portion, and the chip cutting is performed. It can be accommodated within the allowable range, and can be finely divided and finely processed together with the chips generated by the inner peripheral cutting edge 9 portion. This is because, in particular, the length of the cutting blade 9 portion divided by the nick 10 on the outer peripheral side of the drill body 1 is shortened. The cutting blade 9 in which the rotation trajectory of the nick 10 is located on the outermost peripheral side (from the axis O in FIG. It is effective in the cutting edge 9) extending upward.

  As described above, according to the drill with an ultrahigh-pressure sintered body chip having the above-described configuration, it is possible to reliably sever the chips in the length direction as well as the width direction, so that the miniaturization thereof can be achieved. Even when machining workpieces with complex shapes such as engine blocks, chips can be easily discharged in the subsequent process of drilling with the drill, facilitating and improving the efficiency of the entire machining process. Can be urged. On the contrary, since the width W of the honing 11 is made larger than that of the outer peripheral side at the inner peripheral side of the drill body 1 where a large load acts because the peripheral speed is low, higher cutting edge strength is ensured. In addition, it is possible to provide a drill having a longer life by preventing chipping or chipping from occurring in the ultrahigh-pressure sintered chip 8 having high brittleness due to its high hardness.

  In the first embodiment, the width W of the honing 11 is gradually narrowed at a constant rate from the inner peripheral side to the outer peripheral side along the cutting edge 9. As shown in the second embodiment, the width W of the honing 11 is constant in the range in which the cutting edge 9 is divided by the nick 10, and the width W is gradually reduced as it reaches the outer peripheral side of the drill body 1. In addition, the width W of the honing 11 may be reduced on the outer peripheral side in a step shape. In the second embodiment and third to fifth embodiments to be described later, the same reference numerals are assigned to the parts common to the first embodiment shown in FIGS. Is omitted.

  In the first and second embodiments, the honing 11 is the angle honing as described above, and its width W is reduced on the outer peripheral side. And rounded honing that forms a convex curved surface that touches the tip surface 8B smoothly, and a composite honing in which the intersecting ridgeline between the side surface 8A of the angle honing and the tip surface 8B is rounded honing. It may be made smaller on the side. Furthermore, when the honing 11 includes angle honing, the angle with respect to the side surface 8A may be changed toward the outer peripheral side.

  Furthermore, the drill with an ultrahigh-pressure sintered body tip of the first embodiment is a double margin type drill in which a margin portion 13 is also formed on the heel side of the outer periphery of the cutting blade portion 3. It may be a single margin type in which only the margin portion 6 connected to the rear side in the drill rotation direction T of the chip discharge groove 4 is formed on the outer periphery. Further, the number and arrangement of the nicks 10 can be appropriately set according to the outer diameter and the number of the cutting blades 9. For example, the number of nicks 10 is different between the cutting blades 9 or the rotation trajectory of the nick 10 between the adjacent cutting blades 9. May be equally spaced in the radial direction.

  By the way, when the width W of the honing 11 is reduced on the outer peripheral side of the drill body 1 in this way, the cutting edge 9 is formed on the high-hardness ultrahigh-pressure sintered chip 8 depending on the material of the workpiece, processing conditions, and the like. Even in this case, the cutting edge 9 may be damaged or chipped in the outer peripheral portion. Therefore, in order to surely prevent such chipping and chipping in the outer peripheral side portion of the cutting blade 9 without impairing the above-described chip dividing property, as in the third embodiment shown in FIG. The honing 11 that is an angle honing is bent by a plurality of (two in the third embodiment) honings 21 and 22 that bend the honing angles α and β toward the tip of the drill body 1. It is good also as the formed multistage honing. Here, in the third embodiment, the width H of the second honing 22 on the front end side is made smaller than the first honing 21 on the rear end side of the drill body 1, and the first and second The width W of the honing 11 including the honings 21 and 22 is larger on the outer peripheral side than on the inner peripheral side.

  Therefore, according to the third embodiment, the width W of the honing 11 including the first honing 21 on the rear end side is further increased in order to suppress the chip compression ratio particularly in the cutting edge 9 portion on the outer peripheral side. Even if it is set to a small value, the width H of the second honing 22 on the tip side cut into the workpiece is secured to some extent, so that the cutting edge strength of the cutting edge 9 at this outer peripheral portion is maintained and chipping and chipping are prevented. It becomes possible to prevent.

  Further, as in the fourth embodiment shown in FIG. 8, the cutting blade 9 itself is bent in a multi-stage shape (in the fourth embodiment, 2 in the fourth embodiment so that the tip angle becomes smaller toward the outer peripheral side). It may be formed in a step). Here, in the fourth embodiment, the cutting edge 9 bends at an obtuse angle on the ultrahigh-pressure sintered body chip 8 so that the tip angle decreases from the tip angle γ on the inner peripheral side to the tip angle δ on the outer peripheral side. Has been.

  In the fourth embodiment configured as described above, although the entire length of the cutting blade 9 is increased, the chip on the outer peripheral side of the cutting blade 9 having a small tip angle δ is in the direction perpendicular to the cutting blade 9. Since the thickness is reduced, the load on the cutting edge 9 per unit length is reduced, thereby preventing chipping and chipping at the outer cutting edge 9 portion. In addition, since the chip thickness is reduced in this way, the chip compression ratio on the outer peripheral side can be further reduced to promote more reliable cutting of the chips, and the honing grindstone of the honing grindstone can be formed on the inner and outer periphery of the portion where the cutting blade 9 bends. Since the trajectory does not interfere, the effect that the honing 11 can be easily performed is also obtained.

  Furthermore, as in the fifth embodiment shown in FIG. 9, the outer peripheral end 31 of the cutting edge 9 is formed in a convex curve shape and a so-called corner R is provided, so that the cutting edge 9 on the outer peripheral side particularly You may make it ensure the intensity | strength of this outer periphery edge part 31, and prevent a defect | deletion and chipping. In addition, you may make it combine these 3rd-5th embodiment suitably, ie, bend the cutting blade 9 which gave multistage honing in multistage shape, or make the outer peripheral edge part 31 into a convex curve shape. Alternatively, the outer peripheral end 31 of the cutting blade 9 bent in multiple stages may be formed in a convex curve shape. Further, the chip discharge groove 4 may be a straight groove parallel to the axis O, instead of being spirally twisted as in the above embodiment.

It is a side view which shows the 1st Embodiment of this invention. It is an enlarged side view of the front-end | tip part of the cutting blade part 3 in 1st Embodiment shown in FIG. FIG. 3 is an enlarged side view in the direction of arrow X in FIG. 2. FIG. 3 is an enlarged front view as viewed in the direction of arrow Y in FIG. 2. It is ZZ sectional drawing in FIG. It is an enlarged side view of the front-end | tip part of the cutting blade part 3 which shows the 2nd Embodiment of this invention. It is a figure equivalent to the ZZ sectional view in Drawing 2 showing the 3rd embodiment of the present invention. It is an enlarged side view of the front-end | tip part of the cutting blade part 3 which shows the 4th Embodiment of this invention. It is an enlarged side view of the front-end | tip part of the cutting blade part 3 which shows the 5th Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Drill main body 3 Cutting edge part 4 Chip discharge groove 8 Super high pressure sintered compact chip | tip 9 Cutting edge 10 Nick 11 Honing 21 1st honing 22 2nd honing 31 The outer peripheral edge of the cutting edge 9 O The axis T of the drill main body 1 Rotation direction of drill body 1 W width of honing 11 H width of second honing 22 θ honing angle α honing angle of first honing 21 β honing angle of second honing 22 γ tip of cutting edge 9 on inner peripheral side Angle δ Tip angle of cutting edge 9 on outer peripheral side

Claims (4)

  A plurality of cutting blades extending from the outer periphery of the tip end of the drill body toward the inner periphery side on the tip of the drill body that rotates about the axis are spaced apart in the circumferential direction. These cutting blades are formed with a groove-shaped nick so as to shift the rotation trajectory around the axis line between the cutting blades adjacent in the circumferential direction, and on the outer peripheral side of the cutting blade. A drill with an ultra-high-pressure sintered body chip characterized in that honing which is narrower than the circumferential side is applied.   The drill with an ultra-high-pressure sintered body chip according to claim 1, wherein the honing is a multi-stage honing that bends so that a honing angle increases toward a tip side of the drill body.   The ultra-high pressure sintered body according to claim 1 or 2, wherein the cutting blade is formed in a multi-stage shape that bends so that a tip angle decreases toward an outer peripheral side of the drill body. Drill with tip. The drill with an ultrahigh-pressure sintered body chip according to any one of claims 1 to 3, wherein an outer peripheral end portion of the cutting blade is formed in a convex curve shape.

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