JP2016007684A - Cutting tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cutting tool enabled by enhancing the rigidity to suppress the occurrence of chatter and to enhance the chip discharging property.SOLUTION: A cutting tool 1 comprises: a rod-like shank part 3; an extrusion part 4 disposed at the leading end X of the shank part 3; and a cutting part 5 disposed at the leading end of the extrusion part 4. As viewed on the side of the leading end X, a cutting blade 6 is arranged on one side end A of the cutting part 5. At the one side end A and the other side end B opposite to the one side end A, the shank part 3 is extruded from the extrusion part 4.

Description

  The present invention relates to a cutting tool, and more particularly, to a cutting tool suitable for drilling holes and performing spherical processing and back end surface processing on the bottom of a processing hole.

  Cutting tools for drilling are widely used. For example, in Patent Document 1, a head portion having a width about half that of a tool body in a plan view is formed in the upper half of the head portion along a side end of the tool body at the tip end portion of the tool body having an axial shape. A cutting tool is disclosed in which a cutting edge is provided on the tip side surface of the head portion, and the position of the cutting edge is set to be the center position in the width direction of the tool body in a top view. Moreover, in the cutting tool of patent document 1, providing the recessed part in the chip pocket of a head part is described, and suppressing generation | occurrence | production of the chatter by resonance.

JP 2003-291003 A

  However, in the cutting tool of Patent Document 1, when the width of the head portion is reduced as in the case of drilling a small diameter, the thickness of the head portion is thin, so that the rigidity of the head portion is insufficient and chatter occurs. There was a problem. In such hole machining, spherical machining may be performed to form a spherical surface at the hole bottom of the machining hole. In such spherical processing, when the vicinity of the spherical hole bottom is processed, almost the entire length of the head portion is inserted into the hole, so that the opening of the hole is closed by the tool body. Therefore, when processing the vicinity of the hole bottom in spherical processing, it becomes difficult for chips to be discharged, and the chips may be clogged in the hole.

  The objective of this invention is providing the cutting tool which can raise generation | occurrence | production of chatter, and can improve chip | tip discharge | emission property with respect to the said subject while raising rigidity.

The cutting tool of the present invention is a cutting tool having a rod-shaped shank portion, a rod-shaped protruding portion provided at the tip of the shank portion, and a cutting edge portion provided at the tip of the protruding portion,
When viewed from the front end side, a cutting blade is disposed at one side end of the cutting blade portion, and at the one side end and the other side end opposite to the one side end, the shank is more than the protruding portion. The part is protruding.

  According to the cutting tool of the present invention, the rigidity of the protruding portion can be increased to suppress the occurrence of chatter, and the chip dischargeability can be increased.

A preferred embodiment of the cutting tool of the present invention, using a cutting tool in which a cutting insert having a shank portion, a protruding portion, and a cutting edge portion is attached to a holder, the hole bottom of the work material is spherically processed (A) is sectional drawing seen from the upper surface side, (b) is sectional drawing which looked at (a) from the A side. It is a perspective view of the cutting insert of FIG. (A) is the side view which looked at the cutting insert of FIG. 2 from the front-end | tip X side, (b) is YY sectional drawing of FIG. The top view which is another suitable embodiment of the cutting tool of this invention, and shows the cutting tool which mounted | wore the holder with the cutting insert which consists of two members, a cutting blade part and a support part which has a protrusion part and a shank part. It is. (A) It is a top view which shows the state which processes the bottommost part at the time of carrying out spherical processing to the hole bottom of a work material using the conventional cutting tool, (b) Using the cutting tool of FIGS. It is a top view which shows the state which processes the lowest part at the time of carrying out spherical processing to the hole bottom of a workpiece.

  A cutting tool according to a preferred embodiment of the present invention will be described with reference to the drawings.

  The cutting tool 1 of FIGS. 1 to 3 includes a rod-shaped shank portion 3 having a central axis O, a rod-shaped protruding portion 4 provided at the tip of the shank portion 3, and a cutting blade portion provided at the tip of the protruding portion 4. The cutting insert 2 having 5 is mounted in the insertion hole 11 of the holder 10. The holder 10 is attached to a predetermined position of a processing machine (not shown). FIG. 1 shows a state where the cutting insert 2 is cutting the deepest part in the spherical processing in which the hole bottom 32 of the hole 31 of the work material 30 is processed into a spherical surface.

  As shown in FIG. 3A, the cutting insert 2 has a cutting edge 6 disposed at one side end A of the cutting edge portion 5 when viewed from the tip X side. The arrangement of the shank portion 3 and the protruding portion 4 is as shown in FIG. 3B which is a YY sectional view of FIG. 2. The protruding portion 4 has one side end A side opposite to the one side end A. A vertically long medium-bulging shape with a long length on the two orthogonal ends C and D at a position rotated by 90 ° with respect to the one side end A and the other side end B. I am doing.

  And according to this embodiment, as shown in FIG.3 (b), the shank part 3 protrudes rather than the protrusion part 4 in the one side end A and the other side end B. As shown in FIG. As a result, the lengths of the protruding portions 4 in the orthogonal ends C and D directions are increased and the wall thickness is increased. Therefore, the rigidity of the protruding portions 4 is high, and the occurrence of chatter can be suppressed. Moreover, as shown to Fig.5 (a), in the cutting insert 30 which consists of a conventional structure, there is no clearance gap between the protrusion part 4 and the hole 31 processed, and it becomes difficult to discharge | emit chips. On the other hand, according to this embodiment, as shown in FIG. 5B, in the cutting insert 2, since there is a gap between the protruding portion 4 and the hole 31 to be machined, chips are discharged smoothly. The

  In this embodiment, the ratio (wa / wb) between the protruding width wa of the shank portion 3 at the one side end A and the protruding width wb of the shank portion 3 at the other side end B is 0.24-1. Thereby, the chip discharging property can be improved while increasing the rigidity of the protruding portion 4.

  Here, this embodiment can be particularly suitably employed when an automatic board capable of changing the position of the cutting edge 6 is used as the processing machine. That is, in the lathe, since the position of the cutting edge 6 is fixed, when using the cutting tool of this embodiment, it is necessary to correct the positions of the work material and the cutting tool in the machining program.

  In this embodiment, when viewed from the front end side, at the orthogonal ends C and D, the protruding widths wc and wd of the shank portion 3 with respect to the protruding portion 4 are smaller than wa and wb. Thereby, the rigidity of the protruding portion 4 is improved. Note that wc and wd may be zero.

According to FIGS. 1-3, in the connection part with the protrusion part 4 of the shank part 3, the inclination part 3a is formed in the one side end A so that it may match with the width | variety of the protrusion part 4, and it inclines in the other side end B. A portion 3b is formed, an inclined portion 3c is formed at the orthogonal end C, and an inclined portion 3d is formed at the orthogonal end D. Thereby, it can suppress that stress concentrates on the boundary of the protrusion part 4 and the shank part 3, and a crack generate | occur | produces.

  A cutting blade 6 is formed at one end A of the tip of the cutting blade portion 5. In the figure seen from the tip X side of FIG. 3A, the tip of the cutting blade 6 is located outside the protruding portion 4. That is, the cutting edge 6 is disposed so as to protrude from the protruding portion 4 to the one side end A side. This makes it easier for chips to be discharged. A rake face 7 is formed between the cutting edge 6 of the cutting edge part 5 and the protruding part 4. The rake face 7 is concavely curved so as to guide chips generated by the cutting edge 6 backward, and protrudes from the cutting edge 6 toward the portion 4.

  According to FIG. 1, the rear end of the shank portion 3 of the cutting insert 2 has an inclined surface 8, and the inclined surface 8 is abutted against a positioning pin 12 provided in the insertion hole 11 of the holder 10. 2 is positioned. The shank portion 3 has a flat surface 9 on the side surface, and a screw member 14 is screwed into a through-hole 13 penetrating the insertion hole 11 from the outer periphery of the holder 10, and the tip of the screw member 14 is brought into contact with the flat surface 9. Thus, the cutting insert 2 is fixed to the holder 10. If it is this structure, the positioning accuracy of a longitudinal direction and a rotation direction is high, and the restraint force with respect to rotation is also high. According to FIG. 3, the flat surface 9 is formed as flat surfaces 9 a and 9 b at the opposite orthogonal ends C and D of the shank portion 3, respectively. Accordingly, the cutting insert 2 can be mounted in the reverse direction so that the cutting edge 6 of the cutting insert 2 is positioned on the other side end B side. Moreover, the flat surfaces 9a and 9b can be formed in one process by double-headed machining.

  According to FIGS. 1-3, although the cutting insert 2 has the shank part 3, the protrusion part 4, and the cutting-blade part 5 integrally, this invention is not limited to this. For example, as shown in FIG. 4, the cutting insert 20 includes two members, that is, a cutting blade portion 21 and a support portion 24 having a shank portion 22 and a protruding portion 23, and the support portion 24 is attached to the holder 10. The structure of the cutting tool 26 may be sufficient. In the cutting tool 26, the inclined surface 25 at the rear end of the support portion 24 is brought into contact with the fixing pin 12 of the holder 10 and the tip of the screw member 14 is brought into contact with the flat surface 27 to fix the support portion 24. Then, an insert pocket 28 is provided on the side of the tip of the protruding portion 23, and a substantially flat cutting blade portion 21 is attached to the insert pocket 28 and screwed with a screw member 29 to fix the cutting blade portion 21. It may be a configuration. Furthermore, although not illustrated, the form which mounted | wore the holder which has the shank part and the protrusion part with the cutting insert which consists of a cutting blade part may be sufficient.

  The configuration of the cutting insert 2 that integrally includes the shank portion 3, the protruding portion 4, and the cutting edge portion 5 is particularly effective when the diameter of the processed hole is small. In addition, the cutting insert 2 and the cutting insert 20 are preferably made of cemented carbide such as cemented carbide or cermet having high rigidity and excellent wear resistance, but the cutting tool 26 is caused by chipping or wear of the cutting edge 6. The part to be replaced is only the cutting blade portion 21 and is economical.

  As mentioned above, although embodiment of this invention was illustrated, this invention is not limited to the said embodiment, It cannot be overemphasized that it can become arbitrary, unless it deviates from the objective of invention.

DESCRIPTION OF SYMBOLS 1 Cutting tool 2 Cutting insert 3 Shank part 3a Inclined part 3b Inclined part 4 Protruding part 5 Cutting edge part 6 Cutting edge 7 Rake face 8 Inclined face 9 Flat face 10 Holder 11 Insertion hole 12 Positioning pin 13 Screw member 30 Workpiece material 31 Hole 32 Hole bottom A One side end B Other side end C, D Right angle end X Tip

Claims (7)

A cutting tool having a rod-shaped shank portion, a rod-shaped protruding portion provided at the tip of the shank portion, and a cutting edge portion provided at the tip of the protruding portion,
When viewed from the front end side, a cutting blade is disposed at one side end of the cutting blade portion, and at the one side end and the other side end opposite to the one side end, the shank is more than the protruding portion. Cutting tool with protruding part.   2. The cutting tool according to claim 1, wherein a ratio (wa / wb) of the protruding width wa of the shank portion on the one side end side to the protruding width wb of the shank portion on the other side end is 0.24 to 1. 3. .   When viewed from the front end side, at two orthogonal ends at a position rotated by 90 ° with respect to the one side end and the other side end, the protruding width of the shank portion relative to the protruding portion is the protruding width wa, The cutting tool according to claim 1 or 2, which is smaller than wb.   The cutting tool according to any one of claims 1 to 3, wherein when viewed from the distal end side, the distal end of the cutting blade is located outside the protruding portion at the one side end.   The cutting tool according to any one of claims 1 to 4, wherein a cutting insert having the shank portion, the projecting portion, and the cutting edge portion as a unit is mounted on a holder.   The cutting tool according to any one of claims 1 to 4, wherein a cutting insert comprising two members of the cutting edge part and the support having the shank part and the protruding part is attached to a holder.   The cutting tool according to any one of claims 1 to 4, wherein the cutting insert having the cutting edge portion is mounted on a holder having the shank portion and the protruding portion.

Images