JP4906314B2 - Throwaway insert - 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 has a positive rake angle. And a throw-away insert in which a flank including a main cutting edge is divided by a groove portion 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. However, the main cutting edge forms a groove and breaks. 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

Here, in the processing of a large material where heavy cutting is particularly frequently used, in order to avoid stress concentration at the processing corner of the material, the corner is processed so as to be connected in a large R shape using a throwaway insert having a large corner R. It is common. However, even when the above throw-away insert is used, there is a problem that the cutting resistance of the corner cutting edge increases and chatter vibration during processing also increases. In particular, the cutting force applied to the corner cutting edge has a larger proportion of the back component force than the cutting resistance applied to the main cutting edge. As a result, in cutting using a throwaway insert with a large corner R, the tool body is There was a tendency to push up from below, and the accompanying chatter vibration was a big problem. Furthermore, as the corner R becomes larger, the curved portion of the chips generated by the corner cutting edge also increases, that is, the chips are greatly squeezed, so that the generation direction of the chips becomes unstable. Therefore, the chips generated by the corner cutting edge interfere with the chips generated by the main cutting edge, etc., and are easily entangled and the chip discharge performance is reduced. There was a problem that defects such as deficiencies occurred.

  The present invention has been made to solve such problems of the prior art, and is a throw-away insert used for a turning tool, particularly a throw-away insert having a large corner R used for machining a large material. An object of the present invention is to provide a highly reliable throw-away insert that enables processing with less chatter vibration without increasing cutting resistance and has excellent chip discharge performance.

A rake face formed on the upper surface of the substantially polygonal plate-shaped main body, a seating surface formed on the lower surface of the main body, a flank formed on the side of the main body, and the rake and flank A throwaway insert provided with a main cutting edge formed at a crossed ridge line portion, wherein the main cutting edge comprises a straight cutting edge and a corner cutting edge formed continuously with the straight cutting edge, and the corner The cutting edge is provided on the flank so as to divide the corner cutting edge , and has a concave curved surface and a corner groove portion having a convex curved surface continuous with the main cutting edge side of the concave curved surface, and the corner A virtual extension obtained by extending a tangent line at an end portion on the convex curved surface side of an intersecting ridge line between the concave curved surface and the rake surface of the corner groove portion in a top view. Wire and said straight cutting edge It is characterized in that the angle β between the virtual extension line is perpendicular or acute angle.

With such a configuration, the cutting resistance applied to the corner cutting edge, which increases as the corner R increases, is reduced. In particular, the cutting force applied to the corner cutting edge is larger than the straight cutting edge, and the ratio of the back component force is large, and chatter vibration caused by the thrust from the machining surface of the tool body caused by this back component force is suppressed. In addition, since the chip generated by the corner cutting edge whose corner R increases and the curved portion increases is divided in the width direction, the chip is not greatly squeezed and can be discharged more stably. . Further, when viewed from above, the angle formed by the virtual extension line of the intersecting ridge line between the inner surface of the corner groove and the rake face and the virtual extension line of the straight cutting edge is a right angle or an acute angle. Since the contact area involved is suppressed, cutting resistance can be effectively reduced.

In a top view, two tangents intersecting angles at both end portions of the intersecting ridgeline between the convex surface and the rake face, that 9 is 0 ° ~ 150 °, and the intensity of the corner cutting edge is maintained sufficiently It is desirable because cutting resistance can be reduced. If less than 90 °, intensity chipping because decreases likely to occur in an edge portion of the cutting edge, as long as 150 ° or more, the contact area between the inner surface and the workpiece co over Na groove increases cutting Reduction of resistance is suppressed.

  Further, the corner groove portion is located within a range from one end of the corner cutting edge on the side of the straight cutting edge to 3/4 of the corner cutting edge. The corner groove is formed, which is desirable because cutting resistance can be reduced efficiently.

  In addition, it is desirable that the corner groove portion be formed so as to equally divide the corner cutting edge, since a decrease in strength of the corner cutting edge due to the formation of the corner groove portion can be suppressed.

  Furthermore, it is desirable that a plurality of the corner groove portions be formed on the corner cutting edge because the cutting resistance is effectively reduced in a throw-away insert having a large cutting resistance, particularly a large corner R.

  Further, the cutting resistance applied to the entire throw-away insert is that the straight cutting edge is composed of a divided straight cutting edge formed on the flank and having both ends divided by the main groove portion reaching the rake face and the seating face. As a result, it is possible to perform cutting under more severe cutting conditions required for processing of a large work material.

  Further, the corner cutting edge includes a plurality of divided corner cutting edges divided by the corner groove portion, and projections are formed on the rake face corresponding to the divided corner cutting edges and the divided linear cutting edges. This is desirable because the chips generated by each of the divided cutting edges come into contact with the corresponding protrusions, so that the chips can be curled efficiently and stably.

  Further, since the cutting tool having the above-described throw-away insert and a holder for mounting a plurality of the throw-away inserts on the same circumference suppresses cutting resistance, particularly back force, This is desirable because it is difficult for the cutting tool to be pushed up from the machining surface, and chatter vibration during machining can be reduced.

  According to the throw-away insert of the present invention, the corner cutting edge is divided by forming the corner groove portion, and even when the processing corner portion of the work material is processed to be connected in a large R shape, Since the cutting resistance applied to the corner cutting edge that increases as R increases can be reduced, it is possible to perform highly reliable processing without increasing chatter vibration, and the amount of chips generated by the corner cutting edge can be reduced. Since the restriction is suppressed, a stable chip discharging mechanism can be realized.

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

  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 “insert”) according to an embodiment of the present invention, and FIG. (A) Plan view, (b) Long side side view, (c) Short side side view, (d) Enlarged view of a corner groove portion in the plan view, FIG. 3 is equipped with the insert of the present invention FIG. 4 is a perspective view of a rolling tool, FIG. 4 is a schematic view showing a shoulder process using the rolling tool of FIG. 3, and FIG. 5 is a plan view of an insert according to a second embodiment of the present invention. FIG. 4 is a side view of the long side, and FIG. FIG. 6: is (a) top view, (b) long side side view, (c) short side side view of the insert by the 3rd Embodiment of this invention.

  1 and 2, the insert 1 according to the present embodiment has a substantially polygonal plate shape. A rake face 2 is formed on the upper surface of the main body, a seating surface 3 is formed on the lower surface, and a relief surface 4 is formed on the side surface. Has been. A main cutting edge 5 is formed at the intersecting ridge line portion between the rake face 2 and the flank face 4, and the main cutting edge 5 includes a straight cutting edge 55 in a straight portion and a corner cutting edge 7 in a curved portion. The corner cutting edge 7 is formed at a corner of the insert 1, and the corner cutting edge 7 is composed of a plurality of divided corner cutting edges 7 a divided by the corner groove 8.

In FIG. 3, the perspective view of the rolling tool 10 equipped with the insert 1 of the present invention is shown. Here, the turning tool 10 includes an insert 1 and a substantially cylindrical holder 11 on which the insert 1 is detachably mounted. In the present embodiment, the holder 11 mounts a plurality of, for example, six inserts on the outer peripheral portion at intervals in the holder circumferential direction. In the present embodiment, the holder 11 has a plurality of combinations of inserts arranged in the circumferential direction, for example, two rows in the holder axial direction. Such a rolling tool 10 is used for heavy cutting with a large amount of cutting with one insert 1 at a time, particularly for cutting large workpieces. A plurality of chip pockets 12 are formed at the outer peripheral tip of the holder 11, and the insert 1 is attached to each outer peripheral position in the chip pocket 12. Specifically, the insert 1 is mounted so that the main cutting edge 5 is positioned on the outermost periphery with the rake face 2 facing in the rotational direction, and the corner cutting edge 7 is positioned on the outermost peripheral tip. Cutting is performed by rotating the blade 55 and the corner cutting edge 7 together with the holder 11.

  Furthermore, in FIG. 4, the state which shoulder-processes using such a rolling tool 10 is shown. In the figure, machined surfaces 14 and 15 that are orthogonal to each other are formed on the surface of the work material 13 by cutting. Here, the corner 16 where the machining surface 14 and the machining surface 15 are orthogonal to each other is machined in an R shape in order to prevent generation of cracks due to stress concentration. The size of the R portion formed in the corner portion 16 is required to increase as the material becomes larger.

  Conventionally, in order to reduce the cutting resistance of heavy cutting frequently used in large materials, inserts in which the main cutting edge is divided by a groove portion have been widely used. However, in the end mill processing as described above, the cutting resistance of the corner cutting edge 7 increases as a result of using an insert with a large corner R to connect and process the corner 16 in a large R shape. The problem of increased chatter vibration was inevitable. Particularly in processing of a large material, the cutting force main body tends to be pushed up from the processing surface 15 at the time of cutting due to the increase of the cutting resistance and the increase of the back component force received from the processing surface 15 among them. The resulting chatter vibration has been a major problem in the processing of large materials.

  Furthermore, as the corner R increases, the chips generated by the corner cutting edge 7 are greatly squeezed, that is, curved in the width direction, so that the chips generated by the straight cutting edge 55 are easily entangled. The waste discharging direction becomes unstable, and chips are accumulated on the work surface of the work material, which causes problems such as biting into the cutting edge.

  On the other hand, in the insert 1 of the present invention shown in FIGS. 1 and 2, the corner cutting edge 7 is composed of a plurality of divided corner cutting edges 7a divided by the corner groove portion 8 as described above. Even in shoulder machining, cutting resistance applied to the corner cutting edge 7 can be suppressed. As a result, the back component force received from the machining surface 15, that is, the force by which the cutting tool is pushed up from the machining surface 15 is reduced, so that chatter vibration during machining is also suppressed. Moreover, the chip | tip produced | generated by the division | segmentation corner cutting edge 7a has a narrow width | variety, and a restriction | limiting is suppressed, ie, the curvature of the width direction of a chip | tip is suppressed. As a result, since the chips are curled in a stable direction, the chips are not easily entangled with each other, and good chip discharge performance is obtained. As a result, chipping is eliminated and chipping and chipping are suppressed. .

Further, as shown in FIGS. 2A and 2D, the inner surface of the corner groove portion 8 is formed to have a convex curved surface close to the flank 4. Specifically, in this embodiment, two convex curved surfaces 17 and 17 ′ close to the flank 4 are formed on the inner surface of the corner groove portion 8, and one concave curved surface is formed continuously with the convex curved surface. Among them, at least to have a corner groove 8 inner surface convex curved surface adjacent to the flank face 4, it is possible to maintain the strength of the corner groove-side end of the divided corner cutting edge 7 a. That is, if the portion is formed in an R shape, stress concentration is suppressed and the cutting edge strength is increased, so that the cutting edge strength is maintained while reducing cutting resistance.

  2A and 2D, it is preferable that the corner angle α of the convex curved surface adjacent to the flank 4 is 90 ° to 150 ° on the inner surface of the corner groove portion 8. Here, a description will be given using the corner angle α of the convex curved surface 17 on the straight cutting edge 55 side, out of the two convex curved surfaces 17 and 17 ′ close to the flank 4 on the inner surface of the corner groove portion 8. As shown in FIG. 2D, the corner angle α means an angle formed by the tangent lines X and Y at both ends of the convex curved surface 17 when the insert is viewed from above. Of the two tangents at both ends of the convex curved surface 17, the tangent on the concave curved surface side of the inner surface of the corner groove 8 is defined as tangent X, and the tangent on the divided corner cutting edge 7 a side is defined as tangent Y. At this time, if α is smaller than 90 °, the cutting edge strength of the edge portion of the divided corner cutting edge 7a is lowered and the chip tends to be lost. On the other hand, if α is larger than 150 °, the contact area between the inner surface of the corner groove 8 and the work material increases, so that the cutting resistance increases.

Furthermore, since the angle β formed by the intersecting ridge line 18 between the inner surface of the corner groove 8 and the rake face 2 and the straight cutting edge 55 is a right angle or an acute angle, the contact area involved in the cutting is suppressed. This is desirable because a reduction in resistance is effectively exhibited. The angle β referred here, in the insert top view, which means the angle between the imaginary prolongation line of the virtual prolongation line and the straight line cutting edge 55 of the intersecting ridgeline 18. At this time, by forming the corner groove portion 8 so that β is 90 ° or less, it is possible to reliably reduce the cutting resistance with the work material on the straight cutting edge 55 side in the inner surface of the corner groove portion 8. This is desirable because it can be done. When β is 90 ° or more, the inner surface of the corner groove 8 is not in a position where it escapes from the divided corner cutting edge 7a, and is involved in cutting. Therefore, the cutting resistance increases with the contact area between the inner surface of the corner groove 8 involved in cutting and the work material.

If the intersecting ridge line 18 between the inner surface of the corner groove 8 and the rake face 2 is a straight line, the measurement of the angle β is easy. However, as in this embodiment, between the inner surface of the corner groove 8 and the rake face 2. When the intersection ridge line 18 includes a curve, the angle β is defined as follows. As shown in (d) of FIG. 2, as a virtual prolongation line of the intersecting edge line 18, the two tangents X at both ends of the convex curved surface 17 in the insert top view of the Y, concave corner groove 8 inner surface the tangent of the curved side with a tangential X, the angle between the imaginary prolongation line Z of該接line X and the straight line cutting edge 55 and beta.

  Furthermore, it is preferable that the corner groove portion 8 is located within a range from the one end 20 on the straight cutting edge side of the corner cutting edge 7 to 3/4 of the corner cutting edge 7. Specifically, in the top view of the insert, the corner groove portion 8, that is, the two intersections 19 and 19 ′ between the inner surface of the corner groove portion 8 and the corner cutting edge 7 in the top view are up to 3/4 of the corner cutting edge 7. If it is in range. Further, 3/4 of the corner cutting edge 7 means one end of the straight cutting edge when the virtual corner R curve connecting the one end 20 and the other end 20 'of the corner cutting edge 7 is equally divided. A position from 20 to 3/4. At this time, when the corner groove portion 8 is located at a position exceeding 3/4 of the corner cutting edge 7, the groove portion is formed in the portion of the corner cutting edge 7 that is not significantly involved in cutting, and the corner groove portion 8 is formed. Reduction of cutting resistance due to is not effectively exhibited.

  Further, the corner groove 8 is formed so as to equally divide the corner cutting edge 7. By setting it as such a structure, the cutting resistance can be reduced, suppressing the strength fall of the corner cutting edge 7. FIG. When the corner groove portion 8 is formed by being localized with respect to the corner cutting edge 7, the strength of the cutting edge portion where the groove portion is formed is remarkably lowered, and it is difficult to suppress chatter vibration caused by being pushed up from the processing surface of the tool body. It will be enough.

  Here, in the insert 1 in which the corner groove portion 8 is formed in the corner cutting edge 7 according to the present embodiment, since the corner groove portion 8 is not cut, only a single type of insert 1 is attached to the holder 11. Therefore, a strip-like uncut portion is inevitably generated on the processed surface of the work material. On the other hand, in the rolling tool 10 shown in FIG. 3 described above, the insert 1 in which the corner groove 8 is formed in the corner cutting edge 7 according to the present embodiment, and the corner groove 8 is formed in the corner cutting edge 7. By alternately arranging the inserts 101 that are not present on the same circumference of the holder 11, the uncut portion due to the corner grooves 8 of the insert 1 is cut by the corner cutting edges 7 of the insert 101. By doing so, the level | step difference which arises in the processed surface of the workpiece after cutting can be suppressed. In the rolling tool 10 shown in FIG. 3, the insert 1 having the corner groove 8 and the insert 101 not having the corner groove 8 are alternately mounted in the circumferential direction, and the same type of insert is mounted in the axial direction. Indicates the state that has been performed.

  Next, the insert 21 according to the second embodiment of the present invention will be described with reference to FIG. 5 and the insert 21 according to the third embodiment will be described with reference to FIG. In addition, about the structure similar to the insert 1 of embodiment shown in FIG. 1 and FIG. 2, the same code | symbol is attached | subjected and the overlapping description shall be abbreviate | omitted.

  As shown in FIG. 5, in the insert 21 according to the second embodiment, the straight cutting edge 55 is composed of a plurality of divided straight cutting edges 5 a divided by a plurality of main grooves 6 formed on the flank 4. . In addition to the corner groove 8, the main groove 6 is formed on the flank 4 with both ends reaching the rake surface 2 and the seating surface 3 so as to divide the straight cutting edge 55. In addition to the suppression of the cutting resistance, it is possible to suppress the cutting resistance applied to the straight cutting edge 55, so that cutting under severer cutting conditions such as cutting conditions for large materials can be realized.

  In the present embodiment, three main groove portions 6 are arranged on the straight cutting edge 55, but the present invention is not limited to this, and the main groove portion 6 is considered in consideration of suppression of cutting edge strength and cutting resistance. You can choose the number of.

  As shown in FIG. 6, in the insert 31 according to the third embodiment, each of the divided straight cutting edge 5a and the divided corner cutting edge 7a is provided on the rake face 2 adjacent to the divided straight cutting edge 5a and the divided corner cutting edge 7a. Corresponding to at least one protrusion 9 is formed. Specifically, the projections 9 are formed so as to form a pair with respect to the cutting edge that acts as one cutting edge, whether it is the divided straight cutting edge 5a or the corner cutting edge 7a. That is, the cutting edge portion (the divided corner cutting edge 7a 'and the divided linear cutting edge 5a') where the divided corner cutting edge 7a and the divided straight cutting edge 5a are connected is divided into the divided corner cutting edge 7a 'and the divided straight cutting edge 5a, respectively. The protrusion corresponding to 'is the same protrusion 9'.

  With such a configuration, the narrow chips generated by the divided straight cutting edges 5a and the divided corner cutting edges 7a are stably curled and divided by the corresponding protrusions 9. As a result, the chips are discharged to the outside without being entangled with the holder or damaging the wall surface of the holder, so that the chip discharge performance is improved and the holder also has a long life.

  In the present embodiment, an example in which the corresponding protrusion 9 is formed on any of the divided cutting edges as described above is shown. However, the present invention is not limited to this, and the cutting edge can be cut according to the size and shape of the protrusion. The number of protrusions 9 is freely selected so as to curl debris efficiently.

  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. 2A is a plan view of the throwaway insert of FIG. 1, FIG. 2B is a side view of the long side, FIG. 2C is a side view of the short side, and FIG. It is a perspective view of the turning tool equipped with the insert of the present invention. It is the schematic which shows the mode of the shoulder process using the rolling tool of FIG. It is (a) top view, (b) long side side view, (c) short side side view of the throwaway insert according to the second embodiment of the present invention. It is (a) top view, (b) long side side view, (c) short side side view of the throwaway insert according to the third embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Insert 2 Rake face 3 Seating face 4 Relief face 5 Main cutting edge 55 Straight cutting edge 5a (5a ') Divided straight cutting edge 6 Main groove 7 Corner cutting edge 7a (7a') Divided corner cutting edge 8 Corner groove 9 (9 ′) Protrusion 10 Turning tool 11 Holder 12 Chip pocket 13 Work material 14, 15 Work surface 16 Corner 17, 17 Convex surface 18 close to the flank 4 Between the inner surface of the corner groove 8 and the rake face 2 in the insert top view Intersecting ridge lines 19, 19 'Intersection point 20 between the inner surface of the corner groove 8 and the corner cutting edge 7 in a top view of the insert 20 Straight edge side one end 20' Straight cutting edge side other end 21 Insert 31 of the second embodiment Third Insert 101 of Embodiment Conventional insert (insert in which no corner groove is formed)

Claims (8)

A rake face formed on the upper surface of the substantially polygonal plate body,
A seating surface formed on the lower surface of the main body,
A flank formed on the side surface of the main body,
In a throw-away insert provided with a main cutting edge formed at an intersecting ridge line portion between the rake face and the flank face,
The main cutting edge comprises a straight cutting edge and a corner cutting edge formed continuously with the straight cutting edge,
The corner cutting edge is provided on the flank so as to divide the corner cutting edge , and has a concave groove and a corner groove portion having a convex curved surface continuous with the main cutting edge side of the concave curved surface , A split corner cutting edge continuous with the corner groove, and
In an upper surface view, an angle formed by a virtual extension line extending a tangent line at an end portion on the convex curved surface side of an intersecting ridge line between the concave curved surface and the rake face of the corner groove portion and a virtual extension line of the linear cutting edge A throwaway insert characterized in that β is a right angle or an acute angle. In a top view, intersecting angles of two tangent at both ends of the intersecting ridgeline between the convex surface and the rake face, the throw-away insert according to claim 1, characterized in that the 90 ° ~150 °. The throwaway insert according to claim 1 or 2 , wherein the corner groove portion is located within a range from one end of the corner cutting edge on the straight cutting edge side to 3/4 of the corner cutting edge. The throwaway insert according to any one of claims 1 to 3 , wherein the corner groove portion is formed so as to equally divide the corner cutting edge. The throwaway insert according to any one of claims 1 to 4 , wherein a plurality of the corner groove portions are formed on the corner cutting edge. The straight cutting blade, according to any one of claims 1 to 5 across formed on the flank, characterized in that it consists of the rake face and divided straight cutting edge which is separated by the main grooves portion reaching said seating surface Throwaway insert. The corner cutting edge is composed of a plurality of divided corner cutting edges divided by the corner groove portion, and projections are formed on the rake face corresponding to the divided corner cutting edges and the divided linear cutting edges. The throw-away insert according to claim 6 . The throw-away insert according to any one of claims 1 to 7 ,
A rolling tool comprising: a holder for mounting a plurality of the throwaway inserts on the same circumference.

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