JP2009119578A - Cutting insert for groove forming - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent damage to a work surface, a cutting insert and the like by surely discharging chips from a cutting area. <P>SOLUTION: Projecting parts 23a to 23c are disposed which project outward from corner parts 22a to 22c of a body part 21, respectively. Cutting edges 24a to 24c of these projecting parts 23a to 23c are formed so that they are oriented toward one side C in a circumferential direction and inclined toward one side Y in a thickness direction. Cutting faces 25a to 25c are formed continuously from these cutting edges 24a to 24c to the body part 21. Chip guide faces 28a to 28c are formed which are continuous with these cutting faces 25a to 25c and extend to the one side C in the circumferential direction. A smooth discharge of the chips 42 is facilitated by guiding the chips generated by these cutting edges 24a to 24c toward the one side C in the circumferential direction, while bending them in a spiral form. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a grooving cutting insert used for grooving a work material such as steel.

  FIG. 14 is a side view showing a conventional grooving cutting insert 1 and FIG. 15 is a plan view of the grooving cutting insert 1 shown in FIG. The grooving cutting insert 1 has a substantially triangular shape having a corner 3 projecting outward from a virtual inscribed circle C, with a bolt insertion hole 2 through which a bolt for fixing to a tool holder is inserted at the center. It has a plate-like main body portion 4 and a protruding portion 6 that protrudes further outward from each corner portion 3 and has a cutting edge 5 formed on the upper edge on the tip side.

  Each protrusion 6 is provided axially symmetrically with respect to the central axis L <b> 1, and a rake face 8 is formed on the upper part of each protrusion 6 so as to continue to the cutting edge 5. Each rake face 8 is inclined from the upper surface 9 to the lower surface 10 of the main body 4 as it goes from the distal end side to the proximal end side of each protrusion 6, that is, downward in FIG. 14. 3 is connected to each inclined surface 11. These inclined surfaces 11 extend in a direction substantially perpendicular to each rake face 8 in plan view.

  Each inclined surface 11 is formed on one of the side surfaces 12a of the side surfaces 12a and 12b forming the sides of the two virtual triangles inscribed by the virtual inscribed circle C of the main body portion 4 and the base end side of each protruding portion 6 is continuous. It forms so that it may incline upwards as it goes inward of the main-body part 4 from an upper edge.

  When a workpiece such as steel is cut by such a grooving cutting insert 1, the chips generated by the cutting blade 5 advance inward along the rake face 8, that is, toward the main body 4 side, As indicated by the arrow A by the inclined surface 11, it is guided upward and discharged after being curled.

Special table 2002-500111 gazette

  However, in the grooving cutting insert 1 of the prior art, since the inclined surface 11 is formed substantially parallel to the cutting edge 5, the chips generated by the cutting edge 5 are separated from the rake face 8 to the main body portion. It is guided to the 4th side, and is further guided by the inclined surface 11 to the upper side of the rake face as indicated by an arrow A, and is curled and discharged in a spiral shape. Such a chip discharge form has no problem in the case of so-called outer diameter processing in which the work material is a pipe body and the outer peripheral surface thereof is processed, but the so-called inner diameter processing in which the inner peripheral surface of the pipe body is processed. In this case, the chips curled in a spiral shape are likely to stay in the processing site and are not easily discharged out of the work material. If chips remain in the inner diameter of the work material, the accumulated chips may damage the surface to be machined, or the chips 5 may be damaged during processing, resulting in damage to the cutting blade 5. There is a problem in work efficiency because the line must be temporarily stopped and chips are discharged manually from the work material.

  An object of the present invention is to provide a grooving cutting insert capable of suppressing damage to a work surface and a cutting insert so that chips are reliably discharged from a processing site.

The present invention is a grooving cutting insert having a substantially triangular and plate-like main body part, and a prismatic projecting part projecting outward from each corner part of the main body part,
The protruding portion is formed with a cutting edge formed at the upper edge of the tip side, and a rake face extending from the cutting edge to the main body portion side,
In the main body portion, a chip guide surface is formed that extends from each corner portion to the one side in the circumferential direction of the main body portion, and opens to the upper surface of the main body portion and the side surface of the main body portion.
In the grooving cutting insert, the cutting edge and the rake face are formed so as to be inclined from the upper surface to the lower surface of the main body portion toward the one side in the circumferential direction.

  According to the present invention, the cutting blade and the rake face are formed to be inclined from the upper surface of the main body portion toward the lower surface as it goes to the one side in the circumferential direction. It is guided toward the upper side of the rake face and toward the inclined direction of the cutting edge and the rake face, that is, one side in the circumferential direction. The cutting edge and the rake face while being guided upward from the lower surface of the main body portion toward the upper surface along the chip guide surface formed so as to extend to one side in the circumferential direction of the main body portion and continue to the rake face. It moves in the same direction by the pushing force to one side in the circumferential direction due to the inclination of the workpiece, and is smoothly discharged toward the outside of the inner diameter of the work material. As it increases, it suppresses damage to the cutting edge caused by chip biting, resulting in a long-life grooving cutting insert.

  Further, the present invention is characterized in that the chip guide surface is formed in a concave shape facing the cutting edge.

  According to the present invention, the chip guide surface is formed in a concave shape facing the cutting edge, so that the chip generated by the cutting edge is one side in the circumferential direction as described above by the inclined cutting edge and the rake face. Since the guide is guided to the one side in the circumferential direction while being further spirally bent by the chip guide surface, the chips can be discharged more smoothly and the stay of chips at the processing site can be further suppressed. Can do.

  According to the present invention, since the cutting edge and the rake face are formed to be inclined to one side in the circumferential direction, the chips generated by the cutting edge are guided upward and to one side in the circumferential direction, and spirally formed by the chip guiding surface. The sheet is discharged toward the outside of the inner diameter of the work material while being bent. As a result, the stagnation of the chips at the processing site is suppressed to increase the chip discharging property, and the damage of the cutting blade due to the chip entrapment is suppressed, so that a long-life cutting insert for grooving can be obtained. Furthermore, since stagnation of chips at the processing site is suppressed, it is not necessary to discharge chips manually, and work efficiency and processing efficiency can be improved.

  Further, according to the present invention, the chip guide surface is formed in a concave shape so as to face the cutting edge, so that the spirally curled chips can be discharged while being smoothly moved to the one side in the circumferential direction. . As a result, even in a narrow processing space, chips are undesirably large and undesirably spread, damaging the work surface of the work material and the cutting edge of the cutting insert for grooving. can do.

  FIG. 1 is a perspective view showing a grooving cutting insert (hereinafter abbreviated as an insert) 20 according to an embodiment of the present invention, and FIG. 2 is a plan view of the insert 20 shown in FIG. Is a left side view of FIG. 2, and FIG. 4 is a front view of FIG. The insert 20 of this embodiment includes a substantially triangular and plate-shaped main body 21 and prismatic protrusions 23a, 23b, and 23c that protrude outward from the corners 22a, 22b, and 22c of the main body 21. Have. The projecting portions 23a, 23b, and 23c include cutting edges 24a, 24b, and 24c formed on the upper edge of the projecting direction, and rakes extending from the cutting edges 24a, 24b, and 24c toward the main body 21 side. Surfaces 25a, 25b, and 25c are formed.

  The main body portion 21 includes a first virtual plane F1 that extends from each corner portion 22a, 22b, 22c to the rake face 25a, 25b, 25c and extends to one side C in the circumferential direction and includes the upper surface 26 of the main body portion 21; Chip guide surfaces 28a, 28b, and 28c that open to second virtual planes F1a, F2b, and F2c including the side surfaces 27a, 27b, and 27c of the main body portion 21 are formed. The cutting edges 24a, 24b, 24c and the rake faces 25a, 25b, 25c are formed so as to incline toward the one side Y in the thickness direction from the upper surface 26 to the lower surface 29 of the main body portion 21 toward the one side C in the circumferential direction. The In addition, it is preferable that the inclination angle of the cutting edge is set in the range of 3 ° to 25 ° from the viewpoint of maintaining the cutting edge strength and enhancing the chip dischargeability as described later. Incidentally, the inclination angle α of the cutting edge in this embodiment is set to 15 °. Here, the inclination angle of the cutting edge can be measured with reference to an imaginary line parallel to the lower surface 29 as shown in FIG. Further, each of the chip guide surfaces 28a, 28b, 28c is formed to be concavely curved facing the cutting blades 24a, 24b, 24c.

  In the main body 21, an insertion hole 30 through which a screw member 32 for fixing the insert 20 to the tool main body 31 described later with reference to FIG. 7 is inserted is formed coaxially with the axis L1. The main body portion 21 is formed with second side surfaces 33a to 33c that are bent and connected to the respective side surfaces 27a to 27c in the circumferential direction one side C. These side surfaces 33a to 33c are formed on a virtual triangle centered on the axis L1 in plan view, and the ridge lines 34a to 34c with respect to the second side surfaces 33a to 33c adjacent in the direction opposite to the circumferential one side C. Cross at a right angle at 34c.

  5 is an enlarged plan view in which the vicinity of the protruding portion 23a of the insert 20 shown in FIGS. 1 to 4 is enlarged, and FIG. 6 is a right side view of FIG. In addition, since each protrusion part 23a-23c is formed in each corner | angular part 22a-22c symmetrically with respect to the axis line L1, 1st protrusion part 23a is demonstrated, About 2nd and 3rd protrusion part 23b, 23c Is omitted. As described above, the protruding portion 23a is formed with the cutting edge 24a and the rake face 25a inclined toward the one side Y in the thickness direction toward the one side C in the circumferential direction, and the chip guide surface 28a is connected to the rake face 25a. It is formed extending in the direction one side C.

  In the protrusion 23a, below the cutting edge 24a, there is a first flank 35 having a first flank angle θ1, and a second flank having a second flank angle θ2 connected to the lower side of the first flank face 35. A surface 36 is formed. Although this clearance angle can be set as appropriate in the usage pattern of the insert, in the present embodiment, the first clearance angle θ1 is set to 15 ° with respect to the vertical line passing through the cutting edge, and the second clearance angle θ2 is similarly set to 25 ° with respect to a vertical line passing through the cutting edge.

  FIG. 7 is a partial plan view showing a state in which the insert 20 shown in FIGS. 1 to 6 is attached to the tool body 31. The insert 20 is fixed to the tool body 31 by the screw member 32 as described above. An insert pocket 37 in which the insert 20 is mounted is formed at the distal end of the tool body 31, and V-shaped restraining surfaces 38 and 39 are formed facing the insert pocket 37. Each constraining surface 38, 39 supports two side surfaces 33a, 33b formed on the main body portion 21 of the insert 20, and in this state, the inside of the work material 40 is cut by the cutting edge 24a provided on the first projecting portion 23a. Groove processing is performed on the peripheral surface. The work material 40 is, for example, a steel pipe, and the axis of the tool body 31 is arranged substantially parallel to the axis of the work material 40.

  Further, the second side surfaces 33a to 33c supported by the constraining surfaces 38 and 39 of the tool body 31 are parallel to the tangent line of the inscribed circle 41 centered on the axis L1, and the first side surfaces 27a to 27c. Compared with 27c, it has a larger area and is supported by the tool body 31 with a large strength, and the restraint stability when the insert is clamped is improved. As a result, the life stability of the cutting blades 24a to 24c is improved.

  In such an insert 20, the cutting edge 24 a and the rake face 25 a are formed so as to be inclined to the one side Y in the thickness direction from the upper surface 26 to the lower surface 29 of the main body portion 21 toward the one side C in the circumferential direction. Chip 42 generated by 24a is smoothly guided to the inclined direction of cutting edge 24a and rake face 25a, that is, one side C in the circumferential direction, and further in the thickness direction from lower surface 29 to upper surface 26 of main body 21 by chip guide surface 28a. While being guided upward on the other side, the cutting edge 24a and the rake face 25a are pushed in the same direction by the pushing force toward the circumferential one side C due to the inclination of the cutting edge 24a and the rake face 25a, and the chip 42 is processed, that is, the cutting edge 24a and the rake face 25a. Can be prevented from staying in the vicinity.

  Further, since the chip guide surface 28a is formed in a concave shape facing the cutting edge 24a, the chip 42 generated by the cutting edge 24a is guided to the one side C in the circumferential direction by the rake face 25a as described above. In addition, it is guided to one side C in the circumferential direction while being further spirally bent by the chip guide surface 28a, and the vicinity of a narrow machining part of the work material 40 without causing the chip 42 to stay in the vicinity of the cutting edge 24a and the rake face 25a smoothly. Can be discharged smoothly and reliably from the space.

  8 is a perspective view showing an insert 20a according to another embodiment of the present invention, FIG. 9 is a plan view of the insert 20a shown in FIG. 8, FIG. 10 is a left side view of FIG. FIG. 9 is a front view of FIG. 8. 12 is an enlarged plan view in which the vicinity of the protruding portion 23a of the insert 20 shown in FIGS. 8 to 11 is enlarged, and FIG. 13 is a right side view of FIG. Note that portions corresponding to those of the above-described embodiment are denoted by the same reference numerals, and description thereof is omitted to avoid duplication.

  The insert 20a of the present embodiment is substantially triangular and has the above-described embodiment in that the corners 22a to 22c of the plate-like main body 21a are formed with protrusions 23a to 23c that protrude outward. The projecting portions 23a to 23c are integrated with the second side surfaces 33a to 33c and the first side surfaces 27a to 27c adjacent to the side surfaces 33a to 33c on the one side C in the circumferential direction. In plan view, it is formed in a wider shape from the cutting edges 24a to 24c toward the second virtual planes F2a to F2c including the side surfaces 27a to 27c, and has high strength.

  Also in such an insert 20a, rake surfaces 25a to 25c are respectively formed on the main body 21 side from the respective cutting blades 24a to 24c, and chips are connected to the rake surfaces 25a to 25c, as in the above-described embodiment. Since the guide surfaces 28a to 28c are formed, the chips 42 generated by the respective cutting blades 24a to 24c are smoothly guided to the one circumferential side C, and the chips 42 are spirally bent by the chip guide surfaces 28a to 28c. It can guide to the circumferential direction one side C, and can discharge | emit the chip | tip 42 stably.

It is a perspective view which shows the cutting insert 20 for grooving of one Embodiment of this invention. It is a top view of the cutting insert 20 for grooving shown in FIG. FIG. 3 is a left side view of FIG. 2. FIG. 3 is a front view of FIG. 2. It is the enlarged plan view which expanded the protrusion part 23a vicinity of the cutting insert 20 for grooving shown in FIGS. FIG. 6 is a right side view of FIG. 5. It is a partial top view which shows the state which attached the cutting insert 20 for grooving shown in FIGS. 1-6 to the tool main body 31. FIG. It is a perspective view which shows the cutting insert 20a for grooving of the other form of implementation of this invention. It is a top view of the cutting insert 20a for grooving shown in FIG. FIG. 9 is a left side view of FIG. 8. It is a front view of FIG. 12 is an enlarged plan view in which the vicinity of a protruding portion 23a of the grooving cutting insert 20 shown in FIGS. 8 to 11 is enlarged. FIG. It is a right view of FIG. It is a side view which shows the cutting insert 1 for grooving of a prior art. It is a top view of the cutting insert 1 for grooving shown in FIG.

Explanation of symbols

20, 20a Cutting insert for grooving (insert)
21 Main body part 22a-22c Corner part 23a-23c Projection part 24a-24c Cutting edge 25a-25c Rake face 26 Upper face 27a-27c First side face 28a-28c Chip guide face 29 Lower face 30 Insertion hole 31 Tool main body 33a-33c 1st Two side surfaces 40 Work material 41 Inscribed circle C One side in the circumferential direction F1 First virtual plane F2a to F2c Second virtual plane L1 Axis Y One side in the thickness direction

Claims (2)

A grooving cutting insert having a substantially triangular and plate-like main body portion, and a prismatic protrusion portion protruding outward from each corner portion of the main body portion,
The protruding portion is formed with a cutting edge formed at the upper edge of the tip side, and a rake face extending from the cutting edge to the main body portion side,
In the main body portion, a chip guide surface is formed that extends from each corner portion to the one side in the circumferential direction of the main body portion, and opens to the upper surface of the main body portion and the side surface of the main body portion.
The cutting insert for grooving, wherein the cutting edge and the rake face are formed to be inclined from the upper surface to the lower surface of the main body portion toward the one side in the circumferential direction.   2. The cutting insert for grooving according to claim 1, wherein the chip guide surface is formed in a concave shape facing the cutting edge.

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