JP2012152871A - Cutting tip, and cutting tool for machining inner diameter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cutting tip having a shank part with high binding force and manufacturable inexpensively, and to provide a cutting tool for machining inner diameter.SOLUTION: This cutting tip 1 includes a bar-like shank part 2, a bar-like arm part 3 which is brazed to the shank part 2 and has a diameter smaller than that of the shank part 2, and a cutting blade part 4 having a cutting blade 5 which is brazed to the front end of the arm part 3 and projects further to the side than the side surface of the arm part 3 when viewed from the front. In this cutting tool T for machining inner diameter, the cutting tip 1 is attached to a holder 20.

Description

  The present invention relates to an internal diameter machining cutting tool including a cutting tip suitable for internal machining of a small diameter hole.

  As a cutting tool for inner diameter processing that processes 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. Cutting tools with such shapes tend to have smaller cutting edges to accommodate small diameter machining, and there are many forms in which the cutting edges reach the end of their lives with little damage to other parts, and more efficient usage is desired. . In such a cutting tool for small-diameter processing, there is a problem that the diameter of the shank portion attached to the holder formed on the rear end side of the rod-like body becomes small, and the binding force of the chip becomes poor. A chip in which the diameter of the shank portion is larger than the diameter of the portion inserted into the inner diameter of the work material is disclosed.

  On the other hand, Patent Documents 3 and 4 disclose a cutting tool in which a cutting edge portion having a cutting edge is brazed to the tip of a tool main body (tool neck, shank).

JP 2001-066022 A JP 2007-307667 A JP 2004-188518 A Japanese Utility Model Publication No. 02-106203

  However, as in the case of Patent Document 2, the shape in which the diameter of the shank part is larger than that of the tip side is higher than that of the tip side, but the chip restraining force is high, but the manufacturing process takes time and money, and the manufacturing cost increases. There was a problem. In addition, when the method of brazing the cutting edge portion to the tool neck as in Patent Documents 3 and 4 is applied to the cutting tip, particularly when the diameter of the tool body is small in order to drill a small diameter hole, There was a problem that only the cutting edge portion protruding in the direction was damaged and the rod-shaped arm portion was not damaged and the tool life was reached.

  The cutting tip of the present invention includes a rod-shaped shank portion, an arm portion that is brazed to the shank portion and has a rod shape smaller in diameter than the shank portion, and brazed to the tip of the arm portion, and the arm portion as viewed from the tip. And a cutting blade portion provided with a cutting blade protruding laterally from the side surface.

  Here, an inclined surface may be formed at the rear end of the shank portion.

  Further, the cutting edge portion is composed of a part of a circle cut smaller than a semicircle in a front end view, and the center of the circle of the cutting edge portion is eccentric in the rake face direction with respect to the center of the arm portion. It may be brazed.

  Further, there are flat surfaces on the side surfaces of the shank portion, the arm portion, and the cutting edge portion, respectively, and when flattening, the flat surfaces may be brazed together.

  And the cutting tool for inner diameter processing of the present invention inserts and fixes the above-mentioned cutting tip into the insertion hole formed from the tip of the holder from the side opposite to the end where the cutting blade used for cutting is formed, Cutting with a cutting blade.

  Since the cutting tip and the cutting tool for machining the inner diameter of the present invention have a thick shank portion, the restraining force is increased and the occurrence of chatter and the like can be suppressed, and the arm portion and the cutting edge portion are brazed separately, so that the manufacturing process Therefore, it is possible to adopt a lower cost processing method and to minimize the processing amount.

An example of the cutting tip of this invention is shown, (a) Perspective view, (b) Top view, (c) Side 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) Perspective view, (b) Top view. (A) Schematic diagram showing a configuration when brazing a shank part, an arm part, and a cutting edge part, which are a part of the manufacturing process of the cutting tip of FIG. 1, and (b) brazed arm part and cutting edge. It is a perspective view which shows the position with a part, (c) The front end view which shows the position of the brazed arm part and a cutting blade part. The other example of the cutting tip of this invention is shown, (a) Perspective view, (b) Top view, (c) Side view, (d) Tip view. It is a top view which shows the cutting tool for internal diameter processing which mounted | wore the holder | tip of the chip | tip of FIG.

  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. FIG. 1A is a perspective view, FIG. 1B is a top view, FIG. 1C is a side view, and FIG. FIG. 2 shows a cutting tool for inner diameter processing in which the cutting tip of FIG. 1 is mounted on a holder, (a) a perspective view and (b) a top view. 3A is a schematic diagram showing a configuration when brazing a shank portion, an arm portion, and a cutting edge portion, which are a part of the manufacturing process of the cutting tip of FIG. 1, and FIG. 3B is a brazed arm portion. It is a perspective view which shows the position of a blade and a cutting blade part, (c) The front end view which shows the position of the brazed arm part and a cutting blade part. 4A is a perspective view, FIG. 4B is a top view, FIG. 4C is a side view, and FIG. 4D is a front view of another embodiment of the cutting tip of the present invention.

  1 includes a rod-shaped shank portion 2, an arm portion 3 that is brazed to the shank portion 2 and has a smaller diameter than the shank portion 2, and is brazed to the distal end of the arm portion 3 so that the arm is viewed from the distal end. The cutting edge part 4 provided with the cutting edge 5 which protruded to the side rather than the side surface of the part 3 is comprised.

  By brazing these two places, since the diameter of the shank part 2 is thick, the restraining force is increased and the occurrence of chatter and the like can be suppressed, and the arm part 3 and the cutting edge part 4 minimize the amount of grinding in the manufacturing process. Can reduce costs. Moreover, since the arm part 3 and the cutting blade part 4 can be recycled separately, resource saving becomes possible. Further, the arm portion 3 is basically cylindrically polished at a portion to be inserted into the hole of the work material during cutting, and then the flat surface 7 is processed. As a result, the chip 1 can be manufactured at a lower cost.

The shank part 2 is made of a metal such as steel or alloy steel, and the arm part 3 and the cutting edge part 4 are made of a hard alloy such as cemented carbide or cermet. Desirable in relation. As the hard sintered body, cemented carbide, cermet, ceramics, diamond and cBN are preferably applicable, and as the metal or alloy steel, high speed steel and hardened steel are also suitably applicable. On the other hand, when the brazing alloy is Ti—Cu or Ti—Cu—Ag alloy, the bonding strength can be increased. In particular, when an active brazing alloy containing Ti as an active metal is used, brazing can be performed with high bonding strength.

  Here, 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 used as a positioning member 22 of the holder 20. It is configured to be fixed by making line contact. With this configuration, the inclined surface 10 is positioned by directly contacting the positioning member 22 provided on the holder 20 at the line contact, so that a flat surface portion is provided on the outer peripheral surface of the shank portion 2, and this is formed from the outer periphery of the holder 20. The screw is not loosened compared with the method of screwing the screw member into contact, the positioning accuracy when restraining the core height direction and the length direction is high, and the rotation of the chip 1 at the time of fixing can be suppressed. .

  Further, the cutting edge portion 4 is composed of a part of a circle cut smaller than a semicircle when viewed from the front end, and the center of the circle of the cutting edge portion 4 is eccentric to the rake face 6 direction with respect to the center of the arm portion 3. It is desirable to be brazed with. 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, 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, and the flat surfaces 7 can be brazed together when brazing. Matching is 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. 1 and 3, the brazing surfaces of the shank portion 2, the arm portion 3, and the cutting edge portion 4 are all formed perpendicular to the axis L of the rod-shaped chip 1. The configuration is not limited to this, and an inclined surface may be used to increase brazing strength.

  Here, a chip pocket 8 is formed following the rake face 6, and the chips generated by the cutting blade 5 are temporarily stored, and the chips are gradually discharged from the gap between the inner wall surface of the work material and the chip 1. Even if a large amount of chips are temporarily generated, it is possible to suppress the clogging of chips near the cutting edge 5 and the inability to cut. Moreover, according to FIG. 1, the front-end | tip of the arm part 3 forms the raised surface 9 which protrudes toward the outer peripheral side toward back, and functions as a chip breaker.

  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.

  In FIG. 2B, a positioning member 22 is provided in the insertion hole 21 so as to be in contact with the inclined surface 10 of the chip 1 or its terminal corner 11. 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. FIG. 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 tip 20 of the holder 20 is positioned closer to the insertion hole 21 than the positioning member 22 to prevent the chip 1 from dropping or rattling. A screw hole 24 that penetrates is formed, a screw member 25 is screwed into the screw hole 24, and the outer peripheral surface of the shank portion 2 of the chip 1 is pressed and fixed at the tip of the screw member 25. At this time, it is desirable that the outer peripheral surface of the shank portion 2 in contact with the screw member 25 is a curved surface. That is, when the shank portion 2 is brought into contact with the screw member 25 in a plane, the chip 1 may be rotated and attached due to manufacturing variations, and the attachment position may be out of order.

  1 has a cutting edge 5 formed at one end of a rod-shaped shank portion 2, the present invention is not limited to this configuration, and as shown in FIG. What formed the cutting blade 5 in the both ends of the shank part 2 may be used. At this time, as shown in FIG. 5 which is a top view of the chip 1 ′ mounted on the holder 30, the screw member 25 is inserted from the front end side of the holder 20 and functions for positioning the opposite cutting edge 5 ′. It can also be set as the structure contact | abutted and fixed to inclined surface 10 '. Although the flat surface 7 ′ can be substituted by the flat surface 7, it is desirable to form the flat surface 7 ′ on the side surface opposite to the flat surface 7 when the shank portion 2 can be easily processed.

  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 portion 4 is small, it is desirable to make it as simple as possible. According to FIG. 3, the cutting edge portion 4 is formed in a circular shape when viewed from the front end before the flat surface 7 to be processed later is formed. Yes.

  And as shown to Fig.3 (a), these are aligned using the flat surface 7 of the shank part 2, the arm part 3, and the cutting-blade part 4, and it mounts like FIG.3 (b) (c). Thereafter, brazing is sequentially performed using a brazing material. Examples of the brazing method include vacuum brazing and brazing by laser irradiation. Further, when brazing, the inclined surface 10 is fixed in contact with the positioning member 22 of the holder 20, and the position of the cutting blade 5 is determined and brazed so that the machining of the cutting blade 5 described later is less. Or may be unnecessary.

  After that, in a state where the inclined surface 10 of the chip 1 or its terminal corner is in contact with the positioning member 23 of the holder 20, processing is performed as desired, and the cutting edge portion 4 and the cutting edge portion 4 as shown in FIGS. When the distal end side of the arm portion 3 is viewed from the distal end, the upper portion is cut from a circular shape except for the flat surface 7 to form a rake face 6, a chip pocket 8, and a raised face 9. Further, the position and shape of the cutting blade 5 are adjusted.

1, 1 'Cutting tip (chip)
DESCRIPTION OF SYMBOLS 2 Shank part 3 Arm part 4 Cutting edge part 5, 5 'Cutting edge 6 Rake face 7 Flat face 8 Chip pocket 9 Raised surface 10, 10' Inclined surface 11 Termination corner | angular part 20, 30 of holder 21 Insertion hole 22 Positioning Member 23 Positioning member mounting hole 24 Screw hole 25 Screw member T Cutting tool for inner diameter machining

Claims (6)

  A rod-shaped shank portion, an arm portion that is brazed to the shank portion and has a smaller diameter than the shank portion, and brazed to the tip of the arm portion to the side of the side of the arm portion when viewed from the tip A cutting tip comprising a cutting edge portion provided with a protruding cutting edge.   The cutting tip according to claim 1, wherein an inclined surface is formed at a rear end of the shank portion.   Further, the cutting edge portion is composed of a part of a circle cut smaller than a semicircle in a front end view, and the center of the circle of the cutting edge portion is eccentric in the rake face direction with respect to the center of the arm portion. The cutting tip according to claim 1 or 2, which is brazed.   The cutting tip according to any one of claims 1 to 3, wherein flat surfaces are present on side surfaces of the shank portion, the arm portion, and the cutting blade portion, respectively, and the flat surfaces are brazed together.   The cutting tip according to any one of claims 1 to 4, wherein at least a part of side surfaces of the shank portion and the arm portion is cylindrically polished.   A cutting tip according to any one of claims 1 to 5 is inserted into an insertion hole formed from the tip of the holder from the side opposite to an end portion on which a cutting blade used for cutting is formed, and fixed to the cutting blade. Cutting tool for internal diameter machining.