JP2015196203A - Edge replaceable metal saw - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an efficient and economical edge replaceable metal saw.SOLUTION: A plurality of cutting inserts 11 of the same shape and the same size of forming a main cutting edge 18 in a ridgeline part of an end surface 15 of making a pair with a square surface 13 of an insert body 12 of a square plate shape and forming a sub-cutting edge 19 in the ridgeline part of a pair of side surface 16 and end surface 15, are installed on the outer periphery of a disk-like metal saw body 1 for rotating in the metal saw rotational direction T around the axis O, by turning the end surface 15 in the rotational direction T, and a partial cutting insert 11A is inclined toward the other circular surface 1B on the rear side in the rotational direction T by projecting the sub-cutting edge 19 of the side surface 16 of turning to one circular surface 1A of the metal saw body 1 from the circular surface 1A, and a residual cutting insert 11B is inclined toward the circular surface 1A on the rear side in the rotational direction T by projecting the sub-cutting edge 19 of the side surface 16 of turning to the circular surface 1B, and the partial cutting insert 11A and the end surface 15 overlap by being dislocated in the axis O direction in a rotary locus around the axis O.

Description

  The present invention relates to a blade-type replaceable metal saw having a plurality of cutting inserts detachably attached to the outer periphery of a disk-shaped metal saw body and used for cutting a work material such as a steel pipe.

  As such a blade-tip-exchangeable metal saw, the inventors of the present invention, for example, in Patent Documents 1 and 2, to the mounting seat to which the cutting insert of the metal saw body is attached and the seating surface of the cutting insert seated on the mounting seat In this proposal, a protrusion and a concave groove that can be fitted to each other are formed, and the cutting insert is firmly attached to the metal saw body by fitting them.

Japanese Patent Laid-Open No. 8-039342 JP 2002-346832 A

  Here, in the cutting edge exchangeable metal saws described in these Patent Documents 1 and 2, only one cutting blade longer than the thickness of the metal saw body is formed on one cutting insert, and this cutting blade is attached to both the metal saw body. The cutting insert is attached so as to protrude from the circular surface, so that the metal saw body is cut without interfering with the work material. However, in such a blade-replaceable metal saw, if the one cutting edge reaches the end of its life due to wear or damage, the cutting insert must be discarded and replaced, which is inefficient and high in cost. become.

  The present invention has been made under such a background, and it is possible to use at least two cutting edges with one cutting insert, and to provide an efficient and economical cutting edge-exchangeable metal saw. It is aimed.

  In order to solve the above problems and achieve such an object, the present invention provides a plurality of cutting inserts spaced in the circumferential direction on the outer periphery of a disk-shaped metal saw body that is rotated in the metal saw rotation direction around an axis. The cutting insert has a rectangular plate-shaped insert body that is detachably attached by opening and removing, and the insert body has a pair of rectangular surfaces and a pair disposed around the insert body. The main cutting edge is formed at a crossed ridge line portion between at least one of the rectangular surfaces and the pair of end surfaces. In addition, a sub-cutting edge is formed at the intersection ridge line portion between the pair of side surfaces and the pair of end surfaces, and the cutting insert of the same shape and the same size has one end surface in the metal saw rotation direction. And the pair of side surfaces are attached in the axial direction, and the at least one square surface is attached toward the outer periphery of the metal saw body. The main cutting edge formed at the intersection ridge line with the end surface of the metal saw is protruded toward the outer peripheral side of the metal saw body, and is inclined toward the inner peripheral side of the metal saw body as it goes rearward in the metal saw rotation direction. In addition, every other cutting insert in the circumferential direction among the plurality of cutting inserts is formed on the intersecting ridge line portion between the one side surface facing the one circular surface side of the metal saw body and the one end surface. The formed secondary cutting edge is projected from the one circular surface, and the one side surface is directed toward the rear side in the metal saw rotation direction. Accordingly, the other cutting inserts are inclined so as to face the other circular surface side of the metal saw body, and every other remaining cutting insert in the circumferential direction has the other side surface and the one end surface facing the other circular surface side. The secondary cutting edge formed at the intersecting ridge line portion is protruded from the other circular surface, and the other side surface is inclined toward the one circular surface side toward the rear side in the metal saw rotation direction. Further, the one end face is shifted in the axial direction and overlaps with the one end face of the part of the cutting inserts in the rotation locus around the axis.

  In the blade type replaceable metal saw configured as described above, the cutting insert has an insert body having an outer shape square plate shape that is 180 ° rotationally symmetric around the center of the rectangular surface of the insert body, and at least one of the rectangular surfaces thereof The main cutting edge is formed at the intersecting ridge line portion between the pair of end faces and the secondary cutting edge is formed at the intersecting ridge line portion between the pair of side surfaces and the pair of end faces. A cutting blade composed of a blade and a sub cutting blade is formed. And when one end face is oriented in the metal saw rotation direction as a rake face and the cutting edge of the side ridge part is used, the at least one rectangular face of the insert body and the side face protruding from the circular face of the metal saw body are Each is inclined to the circular surface side opposite to the inner peripheral side of the metal saw body as it goes to the rear side in the metal saw rotation direction, so that it is formed on the side ridge portion of the other end surface directed toward the rear side in the metal saw rotation direction. The cutting edge is positioned on the inside of the rotation trajectory around the axis with respect to the main cutting edge on one end face, which is the rake face, and the secondary cutting edge protruding from both circular faces, so as not to interfere with the work material can do.

  For this reason, when the cutting edge on the one end face reaches the end of its life due to wear or damage, the cutting insert is rotated 180 ° around the center of the rectangular surface and reattached, so that the rear side in the metal saw rotation direction The other end face that faces the rake face is used as a rake face, and the cutting edge at the edge of the edge can be used for cutting. Accordingly, at least two cutting blades can be used with one cutting insert, the cutting insert can be used effectively, and the work material can be efficiently cut at low cost.

  In addition, the above-mentioned part of cutting inserts and the remaining cutting inserts of the same shape and size are alternately arranged with the auxiliary cutting edge of one end face directed in the metal saw rotating direction from one circular surface and the other circular surface of the metal saw body. Since they are projected and attached in the circumferential direction, the amount of shift in the axial direction in the rotational trajectory around the axis between the one end faces is made equal to each other in the cutting inserts and the remaining cutting inserts. be able to. For this reason, the amount of cutting by these sub-cutting blades can be made substantially equal, so that the cutting insert reattachment time and replacement time due to cutting blade wear etc. can be set simultaneously for all cutting inserts, and either cutting insert can be used. This prevents the cutting blade from being forced to be reattached or replaced even though it can be used sufficiently, so that the cutting insert can be used up more efficiently.

  In such a blade-tip-exchangeable metal saw, the feed amount per blade is generally about 0.2 mm, and the rotation trajectory around the axis of the part of cutting inserts and the remaining cutting inserts. It is desirable that the shift amount in the axial direction between the one end surfaces in the above is in a range of 0.1 mm to 0.2 mm which does not exceed the feed amount per blade. If the amount of displacement exceeds 0.2 mm, the cutting amount (chip thickness) by the secondary cutting edge exceeds the cutting amount by the main cutting edge, and if it is below 0.1 mm, the cutting amount of the secondary cutting edge is larger than the cutting amount by the main cutting edge. The cutting amount is remarkably reduced, and in either case, although one of the main cutting edge and the auxiliary cutting edge can be used, there is a risk that it may be forced to be reattached or replaced due to wear of the other.

  Further, in each of the cutting inserts, from the secondary cutting edge protruding from the circular surface, the other end face directed to the side surface of the insert body on which the secondary cutting edge is formed and the rear side in the metal saw rotating direction. It is desirable that the retreat amount in the axial direction to the sub cutting edge formed at the intersecting ridge line portion is in the range of 0.05 mm to 0.2 mm. If the retraction amount is less than 0.05 mm, the secondary cutting edge of the intersecting ridge line portion between the side surface protruding from the circular surface and the other end surface may interfere with the work material. There is a possibility that the secondary cutting edge of the intersection ridge line portion between the side surface opposite to the side surface protruding from the surface and the other end surface may interfere with the work material.

  In addition, at the corner where the main cutting edge and the sub cutting edge of the cutting insert intersect, a chamfering blade with a chamfered corner is formed so that the main cutting edge and the sub cutting edge intersect directly. As compared with the case, it is possible to prevent the corners from being damaged.

  As described above, according to the present invention, the cutting blade can be used at least twice by one cutting insert, and the cutting material is efficiently and economically cut by effectively using the cutting insert. It becomes possible.

It is a partial side view which shows one Embodiment of this invention. It is a fragmentary top view of embodiment shown in FIG. It is the front view which looked at the embodiment shown in Drawing 1 from the metal saw rotation direction. It is a side view of the cutting insert attached to embodiment shown in FIG. It is a top view of the cutting insert shown in FIG. It is a front view of the cutting insert shown in FIG. It is an enlarged plan view which shows arrangement | positioning of the cutting insert in embodiment shown in FIG. It is the figure which developed the rotation locus | trajectory of the cutting blade when the feed amount per blade is 0.2 mm and the shift amount is 0.25 mm along the feed in the embodiment shown in FIG. It is the figure which developed the rotation locus | trajectory of the cutting blade when the feed amount per blade is 0.2 mm and the shift amount is 0.2 mm in the embodiment shown in FIG. 1 along the feed. It is the figure which developed the rotation locus | trajectory of the cutting blade when the feed amount per blade is 0.2 mm and the shift amount is 0.125 mm along the feed in the embodiment shown in FIG. FIG. 8 is a drawing in which the rotation trajectory of the cutting blade is developed along the feed when the feed amount per blade is 0.2 mm in a blade-type replaceable metal saw in which a cutting insert of the same size as that in FIGS. It is.

  FIGS. 1 to 7 show an embodiment of the blade-tip replaceable metal saw of the present invention, and FIGS. 8 to 10 show the rotation locus of the cutting blade when the shift amount is changed in such a blade-tip replaceable metal saw. It is explanatory drawing developed according to feed. In the present embodiment, the metal saw body 1 is formed in a disk shape around the axis O by a metal material such as steel, and is rotated in the metal saw rotation direction T around the axis O and perpendicular to the axis O. The plurality of (even) cutting inserts 11 that are fed out and attached to the outer peripheral portion of the metal saw body 1 are used for cutting a work material such as a steel pipe.

  A plurality of (even) chip pockets 2 are formed at equal intervals in the circumferential direction so as to be recessed toward the inner peripheral side on the outer peripheral portion of the metal saw body 1. At the corner where the wall surface of the tip pocket 2 facing the metal saw rotation direction T and the outer peripheral surface of the metal saw body 1 intersect, insert mounting is performed so that the corner is cut out in an L shape when viewed in the direction of the axis O. Seats 3 are formed, and the above-mentioned cutting inserts 11 having the same shape and the same size are detachably attached to these insert mounting seats 3, respectively.

  The insert mounting seat 3 includes a planar bottom surface 3A that faces the outer peripheral side of the metal saw body 1 and a planar wall surface 3B that faces the metal saw rotation direction T perpendicular to the bottom surface 3A. It inclines so that it may go to the inner peripheral side of the metal saw main body 1 as it goes to the back side. In addition, at the corner portion where the bottom surface 3A and the wall surface 3B intersect, a relief portion 3C having a circular cross section is formed so as to cut out the corner portion. Further, a concave groove 3D having a square cross section is formed at the center of the bottom surface 3A in the direction of the axis O so as to extend in the circumferential direction of the metal saw body 1 in parallel with the bottom surface 3A. A screw hole 3E is formed perpendicular to 3A.

  The cutting insert 11 attached to such an insert mounting seat 3 has an insert body 12 whose outer shape is made of a hard material such as cemented carbide and has a substantially square plate shape. A pair of rectangular surfaces 13 and 14 and a pair of end surfaces 15 and side surfaces 16 arranged around each of the rectangular surfaces 13 and 14 are provided, and the circumference of the center of the rectangular surfaces 13 and 14 (intersection of diagonal lines of the rectangular surfaces 13 and 14). The shape is rotationally symmetric around 180 °. The rectangular surfaces 13 and 14 have a substantially rectangular shape, and a mounting hole 12A having a circular cross section that penetrates the insert body 12 is opened at the center thereof.

  Among these rectangular surfaces 13 and 14, the first rectangular surface 13 directed toward the outer peripheral side of the metal saw body 1 when the insert main body 12 is attached to the insert mounting seat 3 is rectangular. A groove 13A having a V-shaped cross section extending in the longitudinal direction (the left-right direction in FIG. 5) crosses the opening of the mounting hole 12A and the pair of end surfaces 15 through a position away from the center of the mounting hole 12A. Is formed. In addition, at the center of the second rectangular surface 14 opposite to the first rectangular surface 13, a ridge portion having a square cross section that can be fitted in the concave groove 3 </ b> D formed on the bottom surface 3 </ b> A of the insert mounting seat 3. 14A is also formed so as to extend along the longitudinal direction of the rectangular surface 14, and in the second rectangular surface 14, the mounting hole 12A is open to the protrusion 14A.

  Further, the pair of end faces 15 are formed in a planar shape perpendicular to the longitudinal direction. On the other hand, the pair of side surfaces 16 are formed in a multi-step surface shape in which the central portion in the longitudinal direction is slightly recessed by one step with respect to both end portions intersecting with the pair of end surfaces 15. , 14 and the end face 15 are perpendicularly crossed. However, a chamfered surface 17 is formed at the intersection ridge line portion between the longitudinal both ends of the pair of side surfaces 16 and the first rectangular surface 13, and in the present embodiment, the chamfered surface 17 is formed of these squares. The surface 13 and the side surface 16 are formed in a planar shape that intersects an obtuse angle at the same angle.

  And in the intersection ridgeline part of the said 1st square surface 13 which is at least 1 square surface in this embodiment, and a pair of end surface 15, the main cutting edge 18 is formed, respectively, and said pair of end surface 15 and Sub cutting edges 19 are respectively formed at the intersection ridge lines with the pair of side surfaces 16. Further, a chamfering blade 20 is formed at a corner portion of the end surface 15 where the chamfered surface 17 and the pair of end surfaces 15 intersect. Therefore, in the present embodiment, one insert main body 12 has a pair of end surfaces 15. Two cutting edges including a main cutting edge 18, a secondary cutting edge 19, and a chamfering edge 20 are formed on the side ridge.

  Note that honing such as chamfer honing is applied from the main cutting edge 18 to the chamfering edge 20. Further, the groove 13A formed in the first rectangular surface 13 has a groove depth larger than the width of the honing when viewed from the direction facing the end surface 15 as shown in FIG. Further, the mounting hole 12 </ b> A gradually decreases in diameter as it goes from the first rectangular surface 13 toward the second rectangular surface 14, and then has a constant inner diameter in the middle and penetrates the second rectangular surface 14.

  In such a cutting insert 11, as described above, the protrusion 14A is fitted in the concave groove 3D and the second rectangular surface 14 is brought into close contact with the bottom surface 3A of the insert mounting seat 3 so that the insert body 12 is attached to the insert. After being seated on the seat 3, the clamp screw 4 inserted into the mounting hole 12 </ b> A from the first rectangular surface 13 is screwed into the screw hole 3 </ b> E, so that it can be detachably attached to the metal saw body 1. Accordingly, the first rectangular surface 13 is directed to the outer peripheral side of the metal saw body 1 as described above to serve as an outer peripheral relief surface, and one end surface 15 of the pair of end surfaces 15 serves as a rake surface, and thus the peripheral surface of the metal saw body 1. The other end face 15 is directed to the rear side of the metal saw rotation direction T, and the pair of side faces 16 is directed to the axis O direction of the metal saw body 1.

  With the cutting insert 11 mounted in this manner, the bottom surface 3A of the insert mounting seat 3 is inclined as described above, so that the first rectangular surface 13 is directed to the metal saw rotating direction T. The main cutting edge 18 formed at the crossing ridge line portion with the end face 15 protrudes to the outer periphery of the metal saw body 1 and is inclined to the inner periphery side of the metal saw body 1 as it goes rearward in the metal saw rotation direction T. The radius from the axis O to the main cutting edge 18 projecting to the outer periphery of the metal saw body 1 and the inclination angle (outer clearance angle) of the first rectangular surface 13 are all cutting inserts attached to the metal saw body 1. 11 is equal.

  On the other hand, as shown in FIG. 7, among the plural (even) cutting inserts 11 attached to the metal saw body 1, every other cutting insert 11 </ b> A in the circumferential direction is one circular surface of the metal saw body 1. The auxiliary cutting edge 19 formed at the intersecting ridge line portion between the one side surface 16 facing the 1A side and the one end surface 15 is protruded from the one circular surface 1A so that the one side surface 16 is in the metal saw rotation direction T. It is made to incline so that it may go to the other circular surface 1B side of the metal saw main body 1 as it goes to the back side. Accordingly, the main cutting edge 18 is also slightly inclined with respect to the axis O when viewed from the outer peripheral side of the metal saw body 1. Further, the chamfering blade 20 formed between the auxiliary cutting edge 19 and the main cutting edge 18 protruding from the one circular surface 1A is similarly protruded from the one circular surface 1A.

  On the contrary, every other cutting insert 11B in the circumferential direction is formed at the intersection ridge line portion of the other side surface 16 facing the other circular surface 1B side of the metal saw body 1 and the one end surface 15. The secondary cutting blade 19 is protruded from the other circular surface 1B, and the other side insert 16 is directed to the one circular surface 1A side toward the rear side in the metal saw rotation direction T. It is inclined at the same inclination angle as one of the side surfaces 16. Accordingly, the main cutting edge 18 is also slightly inclined with respect to the axis O in the direction opposite to the part of the cutting inserts 11A.

  Further, the chamfering blade 20 formed between the auxiliary cutting edge 19 and the main cutting edge 18 protruding from the other circular surface 1B is also protruded from the other circular surface 1B. Accordingly, in some cutting inserts 11 </ b> A and the remaining cutting inserts 11 </ b> B, the one end faces 15 are shifted in the direction of the axis O and overlap each other in the rotation locus around the axis O. Here, the amount of protrusion of the auxiliary cutting edge 19 protruding from the one circular surface 1A of the partial cutting insert 11A from the one circular surface 1A and the other circular surface 1B of the remaining cutting insert 11B. The amount of protrusion of the auxiliary cutting edge 19 protruding from the other circular surface 1B is made equal.

  When cutting the work material by feeding the metal saw body 1 perpendicularly to the axis O while rotating the metal saw main body 1 around the axis O in the metal saw rotation direction T as described above, the above-mentioned part of the metal saw body is cut. Since the auxiliary cutting edge 19 and the chamfering blade 20 of the cutting insert 11A and the remaining cutting insert 11B protrude from the alternate circular surfaces 1A and 1B of the metal saw body 1, some cuttings are performed as shown in FIGS. The insert 11A mainly cuts the cut surface of the workpiece facing the one circular surface 1A, and the remaining cutting insert 11B mainly cuts the cut surface of the workpiece facing the other circular surface 1B. Become.

  At this time, the other end face 15 of each cutting insert 11 directed to the rear side in the metal saw rotation direction T is positioned between the protruding auxiliary cutting edge 19 and the chamfering edge 20 in the axis O direction. . In addition, since the other end face 15 is disposed on the inner peripheral side with respect to the main cutting edge 18 projecting to the outer peripheral side of the metal saw body 1, a cutting edge (main part) formed on the side ridge portion of the other end face 15. The cutting edge 18, the auxiliary cutting edge 19, and the chamfering edge 20) do not interfere with the work material.

  For this reason, when the cutting edge of one end surface 15 reaches the end of its life due to wear or the like, the insert body 12 is rotated 180 ° around the circumference of the first rectangular surface 13 with respect to the center of the first rectangular surface 13. By reattaching to the insert mounting seat 3, the work material can be cut with the cutting edge formed on the side ridge portion with the other end face 15 facing the metal saw rotation direction T. That is, since two cutting blades can be used with one cutting insert 11, the insert body 12 of the cutting insert 11 made of cemented carbide or the like can be used effectively, and the workpiece can be cut efficiently at low cost. The material can be cut.

  In FIGS. 2 and 7, when the cutting insert 11 is reattached in this way, the part of the cutting inserts 11 </ b> A and the remaining cutting inserts 11 </ b> B are exchanged, and thus formed on the first rectangular surface 13. The positions of the formed grooves 13A are staggered in these cutting inserts 11A and 11B. In the insert mounting seat 3 of the blade-type replaceable metal saw shown in FIG. 7, an attachment error serving as an index that can be matched with the position of the groove 13 </ b> A so that the cutting insert 11 to be attached when replacing the cutting inserts 11 </ b> A and 11 </ b> B is not mistaken. A prevention groove 5 is formed and opens on the outer peripheral surface of the metal saw body 1.

  The cutting inserts 11A and the remaining cutting inserts 11B have the same shape and the same size, and the auxiliary cutting edge 19 and the chamfering edge 20 of the one end face 15 are alternately arranged in the circumferential direction. Since it protrudes from the circular surfaces 1A and 1B of the metal saw body 1, the inclination angles of the one side surface 16 of some cutting inserts 11A and the other side surface 16 of the remaining cutting inserts 11B are equalized as described above. 9 to 11, the shift amounts t in the direction of the axis O can be made equal to each other in the rotation trajectory around the axis O between the end faces 15 of the cutting inserts 11A and 11B.

  For this reason, the thickness of the chips generated by the auxiliary cutting edge 19 and the chamfering blade 20 can be made substantially equal between the partial cutting inserts 11A and the remaining cutting inserts 11B. Since the cutting amounts of the main cutting edge 18, the auxiliary cutting edge 19 and the chamfering edge 20 are substantially equal, the cutting insert 11 is reattached or replaced due to the wear of the cutting edge. The insert 11 can be substantially simultaneous. Therefore, although the cutting blade can be sufficiently used in either one of the cutting inserts 11A and the remaining cutting inserts 11B, it is less likely to require reattachment or replacement due to wear of the other cutting blade. Further, it is possible to use the cutting insert 11 more efficiently.

  Here, FIGS. 8 to 10 show the shift amount t when the feed amount fz per blade of the metal saw body 1 is 0.2 mm, which is a typical blade edge replaceable metal saw. 9 is greater than the feed amount fz of FIG. 9, 0.2 mm which is equal to the feed amount fz per blade in FIG. 9, and 0.125 mm which is less than the feed amount fz per blade in FIG. Is developed along the feed. Further, FIG. 11 shows that the same cutting insert 11 as shown in FIGS. 8 to 10 is used, and the feed amount fz per blade is 0.2 mm, but the shift amount t is 0 mm. The case where the rotation locus | trajectory of the main cutting edge 18, the subcutting blade 19, and the chamfering blade 20 of the insert 11 corresponds is shown. 8 to 11, the width w of the chamfering blade 20 in the direction of the axis O is 0.4 mm.

  Among these, when the shift amount t shown in FIG. 11 is 0 mm, when the side surface 16 of the insert body 12 is inclined as in the above-described embodiment, the cutting edge formed on the other end surface 15 becomes the cut surface of the work material. Therefore, the side surfaces 16 of all the cutting inserts 11 must be arranged in parallel with the circular surfaces 1A and 1B of the metal saw body 1. Moreover, even when the cutting insert 11 is attached in this way, the side surface 16 intersecting the other end surface 15 rubs the cut surface, and the cutting edge formed on the side ridge portion of the other end surface 15 is As described above, when the insert body 12 is reattached, it may not be usable.

  On the other hand, in the case of FIGS. 8 to 10 in which the shift amount is not 0 mm, cutting is performed so that the auxiliary cutting edge 19 of one end face 15 protrudes from the circular faces 1A and 1B of the metal saw body 1 as described above. By alternately inclining the side surfaces 16 of the insert 11, it is possible to avoid the other end surface 15 from interfering with the cut surface. Further, since the shift amount t can be made equal between some of the cutting inserts 11A and the remaining cutting inserts 11B, the main cutting edge 18, the auxiliary cutting edge 19 and the chamfering edge 20 of these cutting inserts 11A and 11B. The cutting amounts can be made substantially equal to each other.

  However, looking at one cutting insert 11, when the shift amount t shown in FIG. 8 is 0.25 mm exceeding the feed amount fz per blade, the thickness of the chips generated by the main cutting edge 18, that is, The thickness of the chips generated by the sub-cutting blade 19 and particularly the chips generated by the chamfering blade 20 is larger than 0.2 mm, which is equal to the feed amount fz per blade. Therefore, the wear of the sub cutting blade 19 and the chamfering blade 20 may progress more than the main cutting blade 18.

  On the other hand, when the shift amount t shown in FIG. 9 is 0.2 mm, which is equal to the feed amount fz per blade, the thickness of the chips generated by the main cutting edge 18 and the sub cutting edge 19 are generated. The thickness of the chip is equal. Furthermore, when the shift amount t shown in FIG. 10 is 0.125 mm which is smaller than the feed amount fz per blade, the thickness of the chip generated by the chamfering blade 20 is also the same as that of the chip generated by the main cutting blade 18. It becomes approximately equal to the thickness. However, if the shift amount t becomes too small, the state shown in FIG. 11 may be approximated and the cutting edge of the other end face 15 may not be used. It is desirable that the feed amount fz is 0.2 mm or less and 0.1 mm or more.

  Further, in each cutting insert 11, as shown in FIG. 7, the auxiliary cutting edge 19 is formed from the auxiliary cutting edge 19 of the one end face 15 protruding from the circular surfaces 1 </ b> A and 1 </ b> B of the metal saw body 1. The retraction amount b in the direction of the axis O to the auxiliary cutting edge 19 formed at the intersecting ridge line portion between the side surface 16 of the insert body 12 and the other end surface 15 is preferably in the range of 0.05 mm to 0.2 mm. . When the retraction amount b is smaller than 0.05 mm, the auxiliary cutting edge 19 at the intersecting ridge line portion between the side surface 16 of the insert body 12 and the other end surface 15 protruding from the circular surfaces 1A and 1B interferes with the cutting surface of the work material. On the other hand, if the retraction amount b is larger than 0.2 mm, the auxiliary cutting edge 19 on the cross ridge line portion between the side surface 16 opposite to the side surface 16 protruding from the circular surfaces 1A and 1B and the other end surface 15 is conversely formed. May interfere with the cut surface.

  In the cutting insert 11 according to the present embodiment, the pair of side surfaces 16 of the insert main body 12 are formed in a multi-step surface shape in which the central portion in the longitudinal direction is slightly recessed with respect to both end portions. For this reason, in the center part of these side surfaces 16, it becomes possible to ensure sufficient clearance with the cut surface of a work material, and to prevent interference more reliably.

  Furthermore, in the cutting insert 11 in the present embodiment, a chamfering blade 20 having a chamfered corner is formed at a corner of the pair of end surfaces 15 where the main cutting edge 18 and the auxiliary cutting edge 19 intersect. . For this reason, it is possible to prevent the cutting edge from being broken at the corners as compared with the case where the main cutting edge 18 and the sub cutting edge 19 intersect each other directly perpendicularly. It is possible to further extend the service life.

  However, if the width w in the direction of the axis O of the chamfering blade 20 with the cutting insert 11 attached to the metal saw body 1 is too large, the thickness of the chips generated by the chamfering blade 20 as shown in FIG. When this is large, the chamfering blade 20 may be worn out at an early stage, so that the life of the cutting insert 11 may be shortened. For this reason, when the chamfering blade 20 is formed in this way, the width w in the direction of the axis O is preferably 0.5 mm or less.

  In the present embodiment, the protrusion 14A is formed on the second rectangular surface 14 of the insert body 12 of the cutting insert 11, and can be fitted to the groove 3D formed on the bottom surface 3A of the insert mounting seat 3. However, the bottom surface 3A is formed in a planar shape without forming such a concave groove 3D, and the second rectangular surface 14 is also formed in a planar shape like the first rectangular surface 13, and the second If the main cutting edge 18 is formed also at the intersecting ridge line portion between the square surface 14 and the pair of end surfaces 15, or if the chamfering blade 20 is formed at the corner where the main cutting edge and the auxiliary cutting edge 19 intersect, By reversing the main body 12 upside down, it is possible to use four cutting blades with one insert main body.

DESCRIPTION OF SYMBOLS 1 Metal saw main body 1A, 1B Circular surface of metal saw main body 1 3 Insert mounting seat 11 (11A, 11B) Cutting insert 12 Insert main body 13 1st square surface (at least 1 square surface) of insert main body 12
14 Second square surface of insert body 12 15 End surface of insert body 12 16 Side surface of insert body 12 18 Main cutting edge 19 Sub cutting edge 20 Chamfering blade O Metal saw body 1 axis T Metal saw rotating direction t Some cutting inserts 11A The amount of shift in the direction of the axis O between the one end faces 15 in the rotation trajectory around the axis O with the remaining cutting insert 11B b The sub cutting edge 19 is formed from the sub cutting edge 19 protruding from the circular surfaces 1A, 1B. The amount of retraction in the direction of the axis O to the auxiliary cutting edge 19 formed at the intersecting ridge line portion between the side surface 16 of the inserted main body 12 and the other end surface 15 directed rearward in the metal saw rotation direction T. w The axis O of the chamfering blade 20 Direction width

Claims (4)

A blade-type replaceable metal saw in which a plurality of cutting inserts are detachably attached to the outer periphery of a disc-shaped metal saw body that is rotated in the direction of rotation of the metal saw around an axis,
The cutting insert has an insert body having a rectangular plate shape, and the insert body includes a pair of rectangular surfaces and a pair of end surfaces and side surfaces arranged around the insert body, and is arranged around the center of the rectangular surface. The main cutting edge is formed at a cross ridge line portion between at least one of the square surface and the pair of end surfaces, and at a cross ridge line portion between the pair of side surfaces and the pair of end surfaces. Has a secondary cutting edge,
The cutting insert having the same shape and the same size is attached with one end face directed in the metal saw rotation direction, the pair of side faces directed in the axial direction, and the at least one rectangular face directed toward the outer periphery of the metal saw body. And
In each of the cutting inserts, the at least one rectangular surface is formed on the rear side of the metal saw rotating direction by causing the main cutting edge formed at the intersection ridge line portion with the one end surface to protrude toward the outer peripheral side of the metal saw body. As it is inclined toward the inner peripheral side of the metal saw body as it goes to
Of the plurality of cutting inserts, every other cutting insert in the circumferential direction is formed at an intersecting ridge line portion between one side surface facing the one circular surface side of the metal saw body and the one end surface. The secondary cutting edge is protruded from the one circular surface, and the one side surface is inclined so as to go to the other circular surface side of the metal saw body as it goes to the rear side in the metal saw rotation direction.
The other remaining cutting inserts in the circumferential direction include the sub-cutting blades formed on the intersecting ridge line portion between the other side surface facing the other circular surface side and the one end surface, and the other circular surface. And the other side surface is inclined to the one circular surface side toward the rear side in the metal saw rotation direction, and the one end surface is part of the part of the rotation trajectory around the axis. An edge-exchangeable metal saw characterized in that the one end face of the cutting insert overlaps with being shifted in the axial direction.   The amount of shift in the axial direction between the one end faces in the rotation trajectory around the axis of the part of the cutting inserts and the remaining cutting inserts is in the range of 0.1 mm to 0.2 mm. The blade tip replaceable metal saw according to claim 1, wherein the blade is replaceable.   In each cutting insert, from the secondary cutting edge protruding from the circular surface, the side surface of the insert body on which the secondary cutting edge is formed intersects the other end surface directed to the rear side in the metal saw rotation direction. The blade tip exchange type according to claim 1 or 2, wherein a retraction amount in the axial direction to the auxiliary cutting edge formed in the ridge line portion is in a range of 0.05 mm to 0.2 mm. Metal saw.   The chamfering blade which chamfered this corner | angular part is formed in the corner | angular part which the said main cutting edge and the said sub cutting edge of the said cutting insert cross | intersect, Any one of the Claims 1-3 The cutting edge replaceable metal saw according to claim 1.

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