JP2013094857A - Cutting tip, and cutting tool for machining inner diameter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive easily-manufactured cutting tip and cutting tool for machining an inner diameter, capable of efficiently supplying cutting oil to a cutting edge section.SOLUTION: The cutting tip 1 has: a bar-like shank part 2; a small-diameter bar-like arm part 3 disposed at an end of the shank part 2 and having a through hole 12 in a longitudinal direction; and the cutting blade part 4 brazed to an end of the arm part 3 while exposing at least part of the through hole 12 and laterally provided with a cutting edge 5 at its end. The cutting tool for machining the inner diameter T includes the cutting tip 1 attached to a holder 20.

Description

  The present invention relates to a cutting tip suitable for machining an inner surface of a small-diameter hole and an inner-diameter machining cutting tool including the cutting tip.

  As a cutting tool for inner diameter processing for processing the inner surface of a hole, for example, as in Patent Document 1, a shape in which a cutting blade is formed on the side of the tip of a rod-shaped body is widely used. In the cutting tool having such a shape, cutting oil is generally used for reducing cutting resistance, cooling, and chip discharge. In Patent Document 1, cutting is performed from a gap in which a throw-away tip at the tip of the holder is inserted. It is configured to supply oil. However, in this configuration, the cutting oil cannot reach the cutting edge efficiently because the oil hole is far from the cutting edge. Especially when the machining diameter is small, the cutting edge does not cut even if a large amount of cutting oil is supplied. In some cases, it was processed due to lack of oil.

  Therefore, Patent Document 2 discloses a method of forming a groove portion extending in the longitudinal direction on the side surface of the rod-shaped portion and more reliably supplying the cutting oil to the cutting blade. Patent Documents 3 and 4 disclose a cutting tool in which an oil hole is disposed at a position closer to the cutting edge of the holder.

JP 2005-238370 A JP 2006-262383 A Japanese Patent Laid-Open No. 2007-075933 Japanese Utility Model Publication No. 05-051511

  However, in the method of forming the groove portion in the rod-like portion as in Patent Document 2, the efficiency of supplying the cutting oil to the cutting blade is improved, but further improvement in efficiency has been desired. Further, in the cutting tools of Patent Documents 3 and 4, since the holder is formed up to the tip, it has not been possible to drill a small diameter hole.

  The cutting tip of the present invention has a rod-shaped shank portion, an arm portion which is provided at the tip of the shank portion and has a small diameter rod shape and has a through hole in the longitudinal direction, and at least a part of the through hole is exposed. And a cutting blade portion brazed to the tip of the arm portion and provided with a cutting blade on the side of the tip.

  The cutting tip and the cutting tool for inner diameter machining of the present invention can be manufactured by forming a through hole in the arm by drilling and then brazing the cutting edge, so that the machining is easy and the cutting oil is surely secured. Therefore, the cutting efficiency can be improved.

An example of the cutting tip of this invention is shown, (a) perspective view, (b) side view, (c) top view, (d) tip view. The cutting tool for internal diameter processing which mounted | worn the chip | tip of FIG. 1 to the holder is shown, (a) A perspective view, (b) It is sectional drawing.

  Hereinafter, an internal diameter machining cutting tool T that is used by attaching a cutting tip (hereinafter referred to as a tip) 1 according to an embodiment of the present invention to a holder 20 will be described with reference to FIGS. 1 and 2. FIG. 1A is a perspective view, FIG. 1B is a side view, FIG. 1C is a top view, and FIG. FIG. 2 shows a cutting tool for inner diameter machining in which the cutting tip of FIG. 1 is mounted on a holder, and is a (a) perspective view and a (b) sectional view.

  The chip 1 shown in FIG. 1 is disposed at the tip of the shank portion 2, the rod-like arm portion 3 having a small diameter, and brazed to the tip of the arm portion 3 so that the arm portion 3 can be seen from the tip. And a cutting blade portion 4 having a cutting blade 5 protruding sideward from the side surface.

  According to FIG. 1, the arm portion 3 is provided with a through hole 12 in the longitudinal direction, and the through hole 12 functions as an oil hole for supplying cutting oil to the cutting blade 5. According to this configuration, since the through hole 12 serving as an oil hole can be disposed at a position close to the cutting edge portion 5, an efficient cutting oil can be supplied.

  In addition, the arm part 3 and the cutting edge part 4 can be separately recycled, and may be separately manufactured and brazed so that more resource can be saved. In terms of easy formation, the arm portion 3 and the cutting edge portion 4 can be formed integrally.

  Here, the shank part 2 and the arm part 3 are made of metal such as steel or alloy steel, high speed steel or hardened steel, and the cutting edge part 4 is made of hard metal such as cemented carbide, cermet, ceramics, diamond, and cBN. It is desirable to be composed of a sintered body in terms of both performance and cost. On the other hand, when the brazing material for brazing is Ti—Cu or Ti—Cu—Ag alloy, the bonding strength can be increased. In particular, when an active brazing material containing Ti which is an active metal is used, brazing can be performed with high bonding strength.

  In addition, according to FIGS. 1 and 2, an inclined surface 10 is formed at the rear end of the shank portion 2 for positioning when the chip 1 is attached to the holder 20, and the inclined surface 10 is positioned on the positioning member 22 of the holder 20. It is configured to be fixed in contact with the line. In this configuration, the inclined surface 10 is positioned by directly contacting the positioning member 22 provided on the holder 20 with a line contact, so that a flat portion is provided on the outer peripheral surface of the shank portion like a conventional cutting tip. Compared with the method in which the screw member is brought into contact with the holder from the outer periphery of the holder, the screw is not loosened, the positioning accuracy when restraining the core height direction and the length direction is high, and the chip when fixed The rotation of 1 can also be suppressed.

  According to FIG. 2, the cutting oil is supplied from a cutting device (not shown) for attaching the holder 20 to the rear of the insertion hole 21 into which the chip 1 of the holder 20 is inserted. The rear of the hole 21 is filled with cutting oil. The cutting oil filled in the insertion hole 21 flows into the through hole 12 and flows out from the tip of the arm portion 3.

  Further, it is desirable that flat surfaces 7 exist on the side surfaces of the shank portion 2, the arm portion 3, and the cutting blade portion 4, respectively. Since the flat surfaces 7 can be brazed together when brazing, Positioning becomes easy. When the flat surface 7 is formed, the cutting edge 5 is formed not on the outside of the shank portion 2 but on the side close to the center in the front end view. Further, the brazing surfaces of the arm portion 3 and the cutting edge portion 4 are not limited to the configuration formed perpendicular to the axis L of the rod-shaped chip 1 as shown in FIG. It is good also as an inclined surface in order to increase.

  Here, a chip pocket 8 is formed following the rake face 6, and the chips generated by the cutting blade 5 are temporarily accumulated, and gradually chipped with the circulation of the cutting oil from the gap between the inner wall surface of the work material and the chip 1. In this case, even when a large amount of chips are temporarily generated, it is possible to prevent the chips from becoming clogged near the cutting edge 5 and being unable to cut. In addition, cutting oil is more efficiently supplied to a cutting blade by setting it as the structure where the cutting blade part 4 is fixed to the holder 20 in the direction which the chip pocket 8 of the cutting blade part 4 falls by the cutting blade 5 side. Further, in this configuration, the cutting edge portion 4 is composed of a part of a circle cut smaller than a semicircle in the front end view, and the center of the circle of the cutting edge portion 4 is in the direction of the rake face 6 with respect to the center of the arm portion 3. It is desirable to braze in an eccentric state. As a result, a positive clearance angle is formed on the cutting edge 5 and interference of the clearance surface is suppressed, so that the machining of the cutting edge portion 4 can be reduced or omitted. Further, since the cutting edge portion 4 is small in size, it is difficult to produce a mold for molding. However, if it is circular, the mold can be produced relatively easily and molding is also easy.

  Further, as shown in FIG. 1D, the through hole 12 is circular when viewed from the tip, and the cutting edge portion 4 is brazed to the tip of the arm portion 3 with only the semicircle of the through hole 12 exposed. Has been. With this configuration, even if the cross section of the arm portion 3 is reduced in order to process an extremely small inner diameter, a relatively large through hole 12 can be formed, and cutting oil can be efficiently supplied from the through hole 12 to the surface of the chip pocket 8. Can be supplied to.

  On the other hand, as shown in FIG. 2, the inner diameter machining cutting tool T is provided with an insertion hole 21 into which the tip 1 is inserted at the tip of the holder 20, and a cutting blade 5 that uses the tip 1 for cutting is formed in the insertion hole 21. It is inserted and fixed from the inclined surface 10 side opposite to the end portion. Note that, as described above, according to FIG. 2, the rear portion of the insertion hole 21 of the holder 20 is filled with the cutting oil from the portion where the chip 1 is inserted, and the cutting hole 12 communicating therewith is also filled with the cutting oil. Flows in and flows out from the tip of the arm portion 3.

  In FIG. 2B, a positioning member 22 that is in contact with the inclined surface 10 of the chip 1 is provided in the insertion hole 21. A plurality of positioning member mounting holes 23 for inserting rod-shaped positioning members 22 are provided on the side surface of the holder 20. A rod-shaped positioning member 22 is inserted into one of the positioning member mounting holes 23 among the positioning member mounting holes 23. The reason why a large number of positioning member mounting holes 23 are provided is that the protruding amount of the chip 1 can be adjusted appropriately.

  The positioning member 22 only needs to be in contact with the inclined surface 10 of the chip 1 such as a pin or a screw material or the terminal corner 11 thereof, and has a rod shape. A shape may be sufficient and it will not be restrict | limited especially if there exists the surface which faced the cutting edge 5 side of the front-end | tip in the axial direction of the shank part 2. Since the pins can be easily inserted and removed, the protruding amount of the chip 1 can be easily changed.

  Here, according to FIG. 2, in addition to the positioning member 22, the insertion hole 21 extends from the outer peripheral surface of the holder 20 on the tip side of the holder 20 in addition to the positioning member 22 in order to prevent the chip 1 from falling off and rattling. A screw hole 24 penetrating into the screw hole 24 is formed, and a screw member 25 is screwed into the screw hole 24 so that the outer peripheral surface of the shank portion 3 of the insert 1 is pressed and fixed at the tip of the screw member 25. At this time, the outer peripheral surface of the shank portion 3 that comes into contact with the screw member 25 may be a curved surface, but it is desirable that the inclination with respect to the direction perpendicular to the traveling direction of the screw member 25 is within ± 1 °. . That is, when the shank portion 3 is brought into contact with the screw member 25 with a curved surface, the insert 1 does not rotate due to the influence of manufacturing variations and the mounting position accuracy is high, but the plane is inclined within ± 1 °. Then, by adjusting the tightening degree of the screw member 25, the rotation of the insert 1 can be suppressed, and the tightening strength is improved as compared with the curved surface.

  In order to manufacture the cutting tip 1, first, the shank portion 2 provided with the inclined surface 10 at a predetermined position is formed by grinding or die cutting, and the predetermined position on the outer peripheral surface of the shank portion 2 is cylindrically processed. To do. On the other hand, the arm part 3 and the cutting edge part 4 are formed by molding and firing the raw material powder. As a specific example, the arm portion 3 is subjected to cylindrical polishing after sintering, and then the flat surface 7 is formed by grinding. Since the cutting edge part 4 is small, it is desirable to make it as simple as possible.

1 Cutting tip (chip)
DESCRIPTION OF SYMBOLS 2 Shank part 3 Arm part 4 Cutting edge part 5 Cutting edge 6 Rake face 7 Flat surface 8 Chip pocket 10 Inclined surface 11 End corner part of inclined surface 12 Through-hole 20 Holder 21 Insertion hole 22 Positioning member 23 Positioning member attachment hole 24 Screw Hole 25 Screw member 26 Cutting oil supply port 27 Cutting oil supply passage T Cutting tool for inner diameter machining

Claims (5)

  A rod-shaped shank portion; an arm portion provided at the tip of the shank portion and having a small diameter rod-like shape and having a through-hole in the longitudinal direction; and at least a part of the through-hole exposed, A cutting tip provided with a cutting edge portion which is attached and has a cutting edge on the side of the tip.   The cutting tip according to claim 1, wherein the cutting edge portion is made of a hard sintered body, and the shank portion and the arm portion are made of a metal or an alloy.   The cutting tip according to claim 1 or 2, wherein the through hole has a circular shape when viewed from the tip, and the cutting blade portion is brazed to the tip of the arm portion with only a semicircle of the through hole exposed.   Cutting for inner diameter machining, in which the cutting tip according to any one of claims 1 to 3 is inserted into an insertion hole formed from the tip of the holder from the side opposite to the end where the cutting edge used for cutting is formed and fixed. tool.   The cutting tool for inner diameter processing according to claim 4, wherein a chip pocket is formed in the cutting blade portion, and the cutting tip is fixed to the holder in a direction in which the chip pocket is lowered on the cutting blade side.

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