JP4364173B2 - Throw-away insert and turning tool with it - Google Patents

Description

  The present invention relates to a throw-away insert used for a turning tool such as a face mill or an end mill.

Conventionally, as a throw-away insert used for turning tools such as face mills and end mills, especially for cutting tools with a long cutting edge length and a large number of cutting edges, the rake face continuous from the main cutting edge is positive. A throw-away insert having a corner and a flank including a main cutting edge divided by a groove is known (for example, Patent Document 1). Such a throw-away insert is mainly used for cutting such as heavy cutting where a large amount of chips are discharged and has a large cutting resistance at the time of cutting. In addition, since the width of the generated chip is divided into small parts, the cutting resistance is reduced, and the sticking property to the work material is improved, so that the chatter vibration during the processing can be suppressed.
JP 7-299636 A

  However, in the rolling tool 13 used for heavy cutting as described above, since the thickness of the chip is thick and the rigidity is high, the chip 8 generated by the main cutting edge is on the rake face on the center side of the holder. Since it flows toward the end and hits the holder wall surface 14 of the chip pocket and is discharged to the outside using the holder wall surface as a guide, there is a problem that friction occurs between the wall surface and the chip (FIG. 6). reference). That is, when the rolling process is repeated, the holder wall surface 14 of the chip pocket gradually wears and is gradually scraped off. There is a problem that the rigidity of the holder decreases and the processing accuracy deteriorates. In particular, as the chips generated in heavy cutting become thicker, the wear progresses remarkably, and the damaged holder must be replaced at an early stage.

  The present invention has been made to solve such problems of the prior art, and is a throw-away insert used in a turning tool, particularly a turning tool having a long cutting edge length and a large number of cutting edges attached thereto. The purpose of the present invention is to provide a throw-away insert with high cost performance that allows the holder to be used for a long period of time without causing wear on the holder wall surface of the chip pocket.

  The cutting insert of this invention for solving the said subject, and the milling tool using the same consist of the following structures.

(1) It has a substantially polygonal plate shape, and has a rake face on the upper surface and a flank face on the side face, and a main cutting edge at the intersection ridge line portion between the rake face and the flank face. Has a corner R cutting edge continuous with the main cutting edge, and a throwaway insert comprising a plurality of divided main cutting edges divided by at least one groove formed on the flank. In addition, at least one projection corresponding to each of the divided main cutting edges is formed on the rake face, the divided main cutting edge is a first divided main cutting edge continuous with a corner R cutting edge, A second divided main cutting edge that is adjacent to the first divided main cutting edge and has both ends connected to the wall surface of the groove portion in a top view, and the protrusion corresponding to the first divided main cutting edge has the corner Formed so that the width and height gradually decrease toward the R cutting edge. Corresponding to the second divided main cutting edge. The corner R protrusion is formed, and the main cutting edge protrusion is formed so that the width and height gradually decrease toward the first divided main cutting edge. The protrusion to be formed is formed so that the width and the height gradually decrease toward the second divided main cutting edge, and is disposed closest to the substantially central portion of the second divided main cutting edge. Throw away insert featuring

(2) The throwaway insert according to (1) , wherein the main cutting edge protrusion is disposed on a substantially perpendicular bisector of the first divided main cutting edge .

(3) The throw according to (1) or (2) , wherein an extension line in a tapering direction of the main cutting edge protrusion and the first divided main cutting edge are substantially perpendicular to each other when viewed from above. Away insert.

(4) The throw according to any one of (1) to (3), wherein an angle formed between an extension line of the corner R protrusion in a tapering direction and the divided main cutting edge is 60 ° to 85 °. Away insert.

(5) The projection corresponding to the second divided main cutting edge is disposed on a substantially perpendicular bisector of the second divided main cutting edge . Any one of (1) to (4), Crab throw away insert.

(6) The extension line in the tapering direction of the projection corresponding to the second divided main cutting edge is perpendicular to the second divided main cutting edge in a top view (1) to (1) The throwaway insert according to any one of (5).

(7) Any one of (1) to (6), characterized in that a screw hole penetrating to the lower surface is provided substantially at the center of the rake face, and an annular raised portion is provided around the screw hole . The indicated throw-away insert.

(8) The throwaway insert according to any one of (1) to (7) , wherein a top portion of the raised portion is positioned higher than the protrusion .

(9) A turning tool equipped with the throw-away insert according to any one of (1) to (8).

(10) The rolling according to (9 ), wherein the throw-away tip is clamped to a holder with a clamp screw, and a head of the clamp screw is positioned lower than a top of the raised portion. tool.

According to the throw-away insert of the present invention, the chips formed narrow by the respective divided main cutting edges hit the projections formed on the rake face and are curled to a small extent, and are particularly positioned on the corner R cutting edge side. The protrusion corresponding to the divided main cutting edge is formed such that the width and height gradually decrease toward the corner R cutting edge, so that a part of the cross section is formed in an arc shape by the corner R cutting edge. The chips can be curled most efficiently and in a certain direction, and the chips do not hit the holder wall surface in the chip pocket to damage the holder wall surface. In addition, the curl diameter of each chip is small. As a result, the size of the chip is reduced, so that chip discharge from the chip pocket to the outside is smooth, and defects such as chip entrapment are suppressed. Is, it is possible to use for a long time throwaway insert and the holder.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

(First embodiment)
1 to 4 show an embodiment of the present invention. FIG. 1 is an overall perspective view of a throw-away insert (hereinafter abbreviated as an insert) 1 according to an embodiment of the present invention, and FIG. (A) plan view, (b) long side side view, (c) short side side view, FIG. 3 is an overall perspective view of a rolling tool using the insert of the present invention, and FIG. 3 is a schematic cross-sectional view of the rolling tool of FIG. 3 along the line AA, and FIG. 5 shows (a) a plan view, (b) a perspective view, and FIG. 5 of an insert according to another embodiment. 7 is an enlarged perspective view showing an insert mounting state of the cutting tool of the present invention.

1 and 2, the insert 1 according to the present embodiment has a substantially polygonal plate shape, and includes a rake face 2 on the upper surface and a relief surface 3 on the side surface. A main cutting edge 4 is formed at the intersecting ridge line portion between the rake face 2 and the flank 3, and the main cutting edge 4 is divided by a plurality of grooves 5 formed on the flank 3. It consists of a plurality of divided main cutting edges 4a. Further, a corner R cutting edge 7 is formed at the corner of the insert 1 at the intersecting ridge line portion between the side face and the rake face 2, and is located closest to the corner R cutting edge 7 of the main cutting edge 4. It is connected to the divided main cutting edge 4a (first divided main cutting edge) . The second divided main cutting edge adjacent to the first divided main cutting edge is connected to the wall surface of the groove 5 at both ends in a top view. On the rake face 2 adjacent to the divided main cutting edge 4a, at least one projection 6 is formed corresponding to each divided main cutting edge 4a. Specifically, the projection 6 is formed so as to make a pair with each of the divided main cutting edges 4a.

  FIG. 3 shows a perspective view of a turning tool 12 using the insert 1 of the present invention. Here, a plurality of chip pockets 13 are formed at the outer peripheral tip of the holder 12, and the insert 1 is attached to each outer peripheral position in the chip pocket 13. Specifically, the insert 1 is mounted so that the main cutting edge 4 is positioned on the outermost periphery with the rake face 2 facing in the rotation direction, and the main cutting edge 4 rotates together with the holder 11 to perform cutting. Is called.

  In such a rolling tool 12, chips 8 formed by the main cutting edge 4, strictly speaking, the divided main cutting edge 4 a, are formed on the rake face 2 of the insert 1 from the outer peripheral side to the center side of the holder 12, that is, the cutting edge. It flows toward the holder wall surface 14 in the waste pocket 13. According to the configuration using the conventional insert, as shown in FIG. 6, the generated chip 8 curls as it hits the holder wall surface 14 in the forward direction as it is. It is gradually worn away by friction.

  On the other hand, in the insert 1 of the present invention, since the projection 6 is formed on the rake face 2 adjacent to each divided main cutting edge 4a, as shown in FIG. The formed chip 8 hits the projection 6 and curls small. As a result, the chips 8 are discharged to the outside without hitting the holder wall surface 14. By adopting such a configuration, wear of the holder wall surface 14 in the chip pocket 13 can be prevented, and as a result, the holder 12 can have a long life. Furthermore, since the size of each chip 8 is reduced by reducing the curl diameter of the chip 8, chip discharge from the chip pocket to the outside becomes smooth, and the chipping of the main cutting edge is caused by chipping. Thus, the insert 1 can also have a long life.

  As shown in FIGS. 1 and 2 (a), the main cutting edge 4 side of the projection 6 is formed so that the width and height gradually decrease as it approaches the paired divided main cutting edges 4a. Has been. Thereby, the height of the ridge line portion of the protrusion 6 that contacts the chip 8 decreases as it approaches the divided main cutting edge 4a. In other words, the height of the ridge line portion of the protrusion 6 increases as the distance from the divided main cutting edge 4a increases. Therefore, the contact between the protrusion 6 and the chip 8 becomes smooth, and the increase in cutting resistance is suppressed.

  Further, as shown in FIG. 2A, the distance t between the divided main cutting edge 4a and the protrusion 6 is configured to be the shortest at the substantially central portion of the length of each of the divided main cutting edges 4a. Yes. As a result, the chip 6 is brought into contact with the projection 6 at a substantially central portion in the width direction of each chip 8 generated by the divided main cutting edge 4a, and the chip 8 is curled in a certain direction without swinging left and right. Good chip dischargeability can be obtained.

  Further, the ridge line on the at least one main cutting edge 4 side of the projection 6 and the divided main cutting edge 4a that form a pair are in a substantially right angle relationship in the top view of the insert, whereby the chip 8 Can be curled most efficiently in a certain direction.

Further, as described above, the corner R of the insert 1 is formed with the corner R cutting edge 7 continuously with the one divided main cutting edge 4a (first divided main cutting edge). The protrusion 6 corresponding to the divided main cutting edge 4a (first divided main cutting edge) located on the 7 side is formed so that the width and height gradually decrease toward the corner R cutting edge 7, The corner R cutting edge 7 can curl the chips 8 whose cross section is formed in an arc shape most efficiently and in a certain direction.
Further, an angle θ formed by a ridge line on the corner R cutting edge 7 side of the protrusion 6 corresponding to the corner R cutting edge 7 and the divided main cutting edge 4a (first divided main cutting edge) is 60 ° to 85 °. It is preferable in that the chips 8 formed by the corner R cutting edge 7 can be curled more reliably. If θ is smaller than 60 °, the chips 8 are likely to be clogged and the cutting resistance may increase. If θ is greater than 85 °, the chip 8 is difficult to curl, so that not only the wear of the holder wall surface is not improved, but also the chip 8 is increased in size and the chip discharge performance is reduced. There is a risk of defects such as chipping of the cutting edge due to dent.

  Furthermore, the island-shaped portion, specifically, the annular raised portion 15 is formed around the screw hole 16 in the center portion of the rake face 2, so that the curling action of the chip 8 by the protrusion 6 is insufficient. Even underneath, the chips 8 are reliably curled. As shown in FIG. 7, when the insert 1 is mounted on the holder 11, the head of the clamp screw 17 is hidden by the annular ridge 15, that is, the head of the clamp screw 17 is lower than the annular ridge 15. Therefore, the wear of the head of the clamp screw 17 due to the collision of the chips 8 can be prevented.

  1 and 2 exemplify the insert 1 constituted by five divided main cutting edges 4a by dividing the main cutting edge 4 by four grooves 5, but as other embodiments of the present invention, the main cutting edge is shown. FIG. 3 shows an insert 1 constituted by four divided main cutting edges 4a by dividing the blade 4 by three grooves. In the insert having the groove portion 5 in the main cutting edge 4 as in the present embodiment, since the cutting is not performed in the groove portion 5, a strip-shaped uncut portion is generated on the processing wall surface of the work material. By arranging the inserts having different groove portions 5 on the same circumference of the holder, the remaining cutting edge by the groove portion 5 of one insert is processed by the other cutting blade, so that no uncut portion by the groove portion results. .

(Second embodiment)
Next, another embodiment of the present invention will be described with reference to FIG. In addition, about the structure similar to 1st embodiment shown in FIG.1, 2, the same code | symbol is attached | subjected and the overlapping description shall be abbreviate | omitted.

  In the embodiment of FIG. 5, the difference from the embodiment of FIG. 1 and FIG. 2 is that the length of the divided main cutting edge 4a is different, and according to the length of the divided main cutting edge 4a. The protrusions 6 are arranged so that the number of protrusions corresponding to the divided main cutting edges 4a is increased. With such a configuration, even if a wide chip is formed by the longer divided main cutting edge 4a, it can be surely curled.

More specifically, two protrusions 6 corresponding to the longer divided main cutting edge 4a ′ (first divided main cutting edge) continuous to the corner R cutting edge 7 are disposed. A corner R protrusion 6a disposed closest to the corner R cutting edge 7 and a protrusion 6b (main cutting edge protrusion) of the protrusion 6 other than the corner R protrusion 6a. Thereby, the section generated by the divided main cutting edge 4a ′ (first divided main cutting edge) continuous to the corner R cutting edge 7 and the corner R cutting edge 7 has a straight section and an arc-shaped section. The wide chip 8 is curled most efficiently by the corner R projection 6a at the arc-shaped portion and by the projection 6b (main cutting blade projection) other than the corner R projection 6a among the projections. it can.

  Furthermore, two protrusions corresponding to the divided main cutting edge 4a ″ having one end at the corner opposite to the corner R cutting edge 7 among the both ends of the main cutting edge 4 are also provided. Since the corner portion does not contribute to cutting, the cross section of the chip formed by the divided main cutting edge 4a ″ is substantially linear and no portion is arcuate. Therefore, the corner R protrusion 6a is not disposed at the corner, and only two protrusions 6b other than the corner R protrusion 6a among the protrusions 6 are disposed. Since the protrusion 6b is arranged so that the ridge line on the divided main cutting edge 4a side of the protrusion and the divided main cutting edge 4a ″ are positioned substantially at right angles, the generated wide chip 8 can be swung left and right. And can be curled more reliably in a certain direction.

Further, in FIG. 5, only the number of protrusions corresponding to the two divided main cutting edges 4a ′ (first divided main cutting edges) and 4a ″ each having both ends of the main cutting edge 4 is plural. However, in order to obtain the same effect, the number of protrusions corresponding to the divided main cutting edge 4a at any position of the insert may be plural according to the length of the divided main cutting edge 4a.

  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 be made arbitrary, unless it deviates from the objective of invention.

1 is an overall perspective view of a throw-away insert according to an embodiment of the present invention. It is (a) top view of the throw away insert of FIG. 1, (b) Long side side view, (c) Short side side view. It is a whole perspective view of the turning tool using the throw away insert of the present invention. FIG. 4 is a schematic cross-sectional view of the cutting tool of FIG. 3 taken along the line AA and showing a chip generation state. It is (a) top view and (b) perspective view of the throw away insert by other embodiments. It is a schematic diagram which shows the production | generation state of the chip in the rolling tool equipped with the conventional throwaway insert. It is an expansion perspective view which shows the throw away insert mounting state of the cutting tool of this invention.

Explanation of symbols

1 Throw away insert (insert)
2 rake face 3 flank face 4 main cutting edge 4a split main cutting edge 5 groove 6 protrusion 6a corner R protrusion 6b protrusion other than corner R protrusion 6a 7 corner R cutting edge 8 chip 11 holder 12 rolling tool 13 chip pocket 14 Holder wall (in chip pocket) 15 Annular ridge 16 Screw hole 17 Clamp screw

Claims (10)

It has a substantially polygonal plate shape, has a rake face on the upper surface, and a flank face on the side face, a main cutting edge at the intersection ridge line portion of the rake face and the flank face, and a corner portion of the rake face at the corner portion. In a throw-away insert comprising a plurality of divided main cutting edges, in which a corner R cutting edge continuous with the main cutting edge is formed, and the main cutting edge is divided by at least one groove formed on the flank surface,
At least one protrusion is formed on the rake face corresponding to each divided main cutting edge,
The divided main cutting edge includes a first divided main cutting edge that is continuous with the corner R cutting edge, and a second divided main cutting edge that is adjacent to the first divided main cutting edge and has both ends connected to the wall surface of the groove when viewed from above. A blade,
The protrusion corresponding to the first divided main cutting edge includes a corner R protrusion formed so that a width and a height gradually decrease toward the corner R cutting edge, and a width toward the first divided main cutting edge. A main cutting edge protrusion formed so that the height gradually decreases,
The protrusion corresponding to the second divided main cutting edge is formed so that the width and height gradually decrease toward the second divided main cutting edge, and at the substantially central portion of the second divided main cutting edge. Throw-away insert characterized by being placed closest .   The throwaway insert according to claim 1, wherein the main cutting edge protrusion is disposed on a substantially perpendicular bisector of the first divided main cutting edge.   The throwaway insert according to claim 1 or 2, wherein an extension line of the main cutting edge projection in a tapering direction and the first divided main cutting edge are in a substantially right angle relationship in a top view.   The throwaway insert according to any one of claims 1 to 3, wherein an angle formed by an extension line of the corner R protrusion in a tapering direction and the divided main cutting edge is 60 ° to 85 °.   5. The throw according to claim 1, wherein the protrusion corresponding to the second divided main cutting edge is disposed on a substantially perpendicular bisector of the second divided main cutting edge. Away insert.   The throw according to any one of claims 1 to 5, wherein an extension line in a tapering direction of a protrusion corresponding to the second divided main cutting edge is orthogonal to the second divided main cutting edge in a top view. Away insert.   The throwaway insert according to any one of claims 1 to 6, further comprising a screw hole penetrating to a lower surface at a substantially center of the rake face, and an annular raised portion around the screw hole. .   The throwaway insert according to claim 7, wherein the top of the raised portion is positioned higher than the protrusion. A turning tool equipped with the throw-away insert according to any one of claims 1 to 8. The rolling tool according to claim 9, wherein the throw-away tip is clamped to the holder with a clamp screw, and a head portion of the clamp screw is positioned lower than a top portion of the raised portion.

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