JP2015077647A - Forward path and return path longitudinal feed insert, and cutting-edge replacement type rotary cutting tool mounting the insert - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cutting-edge replacement type rotary cutting tool mounting an insert for performing finish processing of a processed face subjected to cutting processing in a forward path, in a backward path of longitudinal feed when subjecting a material to be processed to longitudinal feed processing.SOLUTION: An insert having a polygonal flat plate shape, and having at least two corner parts of corner parts, provided with a corner blade, when being attached to a tool body, includes: a main cutting blade (15a) arranged on an outer peripheral side of the tool body, and connected to an end (t1) on the outer peripheral side of the corner blade; and a first sub-cutting blade (19a) for return-path processing formed toward a cental part of an upper face part (6) of the insert. The height of a cutting face (14a) of the main cutting blade with respect to a lower face part (7) is formed so as to be higher than the central part of the upper face part or the vicinity of the central part, and the cutting blade for the return-path processing includes a flank face lowered from the cutting face toward the upper face part of the main cutting blade.

Description

  The present invention is capable of performing cutting in the forward path and the backward path of the longitudinal feed when performing cutting by longitudinal feed on a work material such as a die, and in particular, finishing the processed surface processed in the forward path in the backward path The present invention relates to an insert that can carry out the above and a blade-cutting-type rotary cutting tool in which this insert is detachably attached to a tool body.

  When cutting the workpiece vertically with a rotary cutting tool, when cutting is performed in the forward and backward paths of the rotary cutting tool to improve cutting efficiency There is. In such vertical feed cutting, if roughing or intermediate finishing is performed in the forward path and finishing is performed in the backward path, it is possible to increase the efficiency of cutting of the work material.

  When cutting with the above-mentioned longitudinal feed forward path and return path using the cutting edge exchange type rotary cutting tool that detachably mounts the insert with the cutting edge, the shape and thickness of the insert, and the insert It is necessary to ensure the strength of the cutting edge by appropriately arranging (forming) the position of the cutting edge to be provided. For example, it is necessary to arrange cutting edges used for cutting in both the forward and backward passes of the longitudinal feed, cutting edges used only for the return path, and the like at appropriate positions of the insert.

  In a cutting edge exchange type rotary cutting tool, Patent Document 1 (Japanese Patent No. 5010895) proposes a cutting tool for performing roughing in the forward feed path and finishing in the return path.

  The invention described in Patent Document 1 is a tip-replaceable rotary cutting tool equipped with an insert having a rectangular or parallelogram shape, and this insert has two long sides opposite to each other among the four sides of the upper surface. The other two opposite parallel sides are short sides, and the edge angles of the two opposing corners are 75 ° to 90 °. When the insert is mounted on the cutting tool, the corner portion of the insert is the corner blade (1), the short side is the bottom blade (2) for forward processing, and the long side is the outer peripheral blade for forward / return processing ( 3) is provided from the corner blade (1) to the outer peripheral blade length (L3) of 0.5 to 6 mm, and subsequently to the outer peripheral blade (3), the cutting edge (4) for backward machining is provided to the outer peripheral blade (3). A longitudinal feed cutting tool provided on the tool axis side with a length (L4) in the direction perpendicular to the tool axis and 0.03 to 0.15 times the interval (H) between the long sides. .

  The longitudinal feed cutting tool disclosed in Patent Document 1 having the above-described configuration can improve the cutting performance when performing the finishing process of the return path without reducing the roughing capability in the outward path process, The cutting performance is improved to provide a longitudinal feed cutting tool with high machining efficiency and improved machining surface accuracy and tool life (see paragraph 0006).

  Patent Document 2 (Japanese Patent Laid-Open No. 8-39321) proposes an invention related to a rotary cutting tool capable of cutting both in the forward movement and in the backward movement. In the invention disclosed in Patent Document 2, by attaching at least one chip (for example, a circular chip) to the tool body so that the rake angle in the axial direction is 0 °, the machining condition is set to the time of forward movement. This is a rotary cutting tool that is the same at the time of backward movement, and that can obtain a cutting surface with uniform roughness even if the tip is applied to the workpiece in both forward movement and backward movement.

  Patent Document 3 (Japanese Patent Laid-Open No. 9-290316) proposes an invention relating to a cutter for finishing a deep vertical wall surface (elevation surface) such as a mold. The cutter for piercing disclosed in Patent Document 3 is a cutter for piercing provided with a throwaway tip having a substantially equilateral triangular plate shape on the outer periphery of the tip of the cutter body. The throwaway tip includes a front blade and a peripheral blade. In the reciprocating processing of the surface of the vertical wall, the work material is cut with the front blade on the one hand and the outer peripheral blade on the other hand, and the outer peripheral blade is opposed to the front blade with the corner blade on the outer peripheral side sandwiched between them. And a configuration with an acute edge angle of about 60 °. This is characterized in that the workpiece is cut with the front blade and the outer peripheral blade by cutting the cutter while reciprocating in the vertical direction.

  Patent Document 4 (Japanese Patent Application Laid-Open No. 2003-19617) is equipped with an insert that can take a sufficiently large axial rake angle, improve sharpness, and perform stable machining with less cutting vibration, and this insert. Inventions related to cutting tools have been proposed. The insert disclosed in Patent Document 4 has a substantially polygonal plate shape, and is provided with a cutting edge on the ridgeline of the upper surface facing the seating surface. From the corner 14A (14B) to the other in the plan view A main cutting edge 16A (16B) extending toward the corner 15A (15B) of the first main cutting edge 17A (17B) and the first main cutting edge 17A (17B) in plan view are provided. A second main cutting edge 18A (18B) provided with an obtuse angle protruding outward from the cutting edge is provided. The first main cutting edge is inclined toward the second main cutting edge so that the distance from the seating surface 11 gradually decreases in a side view, and is recessed toward the second main cutting edge and the seating surface. An obtuse angle is formed, and the first main cutting edge is an insert configured to be shorter than the second main cutting edge (see FIGS. 1 and 2). Further, the upper surface serving as a rake face is provided with a first ridge line rake face that is inclined such that the distance from the first main cutting edge 17A (17B) to the seating surface gradually decreases in the direction of the center in a side view. It is configured.

  In the insert disclosed in Patent Document 4, the first main cutting edge is inclined so that the distance from the seating surface 11 gradually decreases toward the second main cutting edge in a side view. Even if the rake angle is sufficiently large, the envelope of the insert drawn during the rotational movement of the cutting tool can constitute a cylindrical surface. Thereby, it is shown that the biting at the time of cutting becomes smooth and the sharpness is sufficiently improved.

Patent Document 5 (Japanese Patent Laid-Open No. 2013-107154) discloses an invention relating to a cutting insert for suppressing deterioration of the finished surface roughness of a work material due to crater wear on a rake face when turning a high hardness material. Has been proposed.
The cutting insert disclosed in Patent Document 5 is an insert to be mounted on a holder of a cutting edge exchangeable cutting tool, and is formed at the edge of the rake face 2 of the insert body 1 having a polygonal shape, at the corner of the rake face 2. A cutting edge having an arcuate corner edge 7A is formed, and the rake face 2 has a stepped portion 2B in which the rake face 2 is lowered in the middle of the rake face 2 from the tip P of the corner edge 7A. It is the insert formed so that it may cross | intersect. With this insert, it is possible to prevent crater wear on the rake face due to scraping to the cutting edge feed boundary and prevent chipping, chipping, and abnormal wear on the flank surface. It has been shown that deterioration of surface roughness can be sufficiently suppressed.

Patent Document 6 (Japanese Utility Model Laid-Open No. 2-94022 (the full text specification)) proposes a device relating to a cutter equipped with a polygonal flat plate-shaped throw-away tip (insert) that has good chip discharge performance. .
The throw-away tip disclosed in Patent Document 6 has a polygonal flat plate shape, forms a corner blade at at least one corner portion, and at least one ridge line portion connected to the corner portion where the corner blade is formed, In the throw-away tip that has a main cutting edge with the tip continuous with the corner blade, the tip is continuous with the main cutting edge and gradually inwards toward the rear end. The first clearance blade is formed, and the second clearance blade is formed on the rear end side of the first clearance blade, the second clearance blade being inclined outward with respect to the first clearance blade.

  The throw-away tip described in Patent Document 6 has the above-described configuration, that is, the first relief blade is formed radially inward of the tool body with respect to the main cutting edge. A gap is formed between the rear end side of the cutting edge and the work material. Thereby, since the chip | tip discharged | emitted from the main-cutting-blade rear end side is guide | induced to the base end side of a tool main body through this clearance gap, it has been shown that chip | tip discharge | emission property can be improved.

Japanese Patent No. 5010895 JP-A-8-39321 Japanese Patent Laid-Open No. 9-290316 JP 2003-19617 A JP2013-107154A Japanese Utility Model Publication No. 2-94022 (full text description)

  Patent Document 1 described above discloses an insert having a substantially parallelogram plate shape with a corner blade in order to perform processing in the forward path and the return path in the longitudinal feed cutting. This insert is a cutting edge connected to a corner blade on the long side of a parallelogram plate when mounted on a cutting tool, and is provided with an outer peripheral blade for forward and backward processing. This is an insert having a configuration in which a cutting edge for return path machining from the side toward the tool axis is provided, and a bottom edge for outward path machining connected to a corner edge is provided on the short side.

  However, since the upper surface portion (rake face) of the insert disclosed in Patent Document 1 is formed to be parallel to the lower surface portion, the strength of the corner blade, the outer peripheral blade, and the bottom blade is sufficiently ensured. I can't say. In order to ensure the strength of the corner blade, outer peripheral blade, and bottom blade, the height (distance) formed by the rake face formed from the corner portion of the upper surface portion toward the center portion of the upper surface portion from the lower surface portion is the upper surface portion. It is desirable that the height be higher than the central portion of the upper portion or the vicinity of the central portion of the upper surface portion. This is because the thickness of the flank (side surface portion of the insert) of the corner blade, the outer peripheral blade, and the bottom blade can be set large, so that the strength of each of the cutting blades can be ensured. .

  Further, it has been proposed that the incision angle (κ) of the cutting edge for return path disclosed in Patent Document 1 is set to −10 degrees to 45 degrees. The configuration of the flank is not disclosed. By providing a flank with a sufficient clearance angle on the cutting edge for return path machining, it is possible to improve the accuracy of the finishing process of the machining surface performed with the cutting edge for backward path machining and the life of this cutting edge. become.

  Patent Document 2 described above proposes an invention related to a rotary cutting tool in which a tip is mounted to perform both forward and backward cutting operations. This rotary cutting tool is axially attached to the tool body. At least one chip (for example, a circular chip) is mounted so that the rake angle is 0 °, and the machining conditions are the same for the forward movement and the backward movement. However, the shape of the tip for improving the strength of the cutting edge provided in the tip, the configuration of the cutting edge, and the like are not disclosed. Further, since the forward path machining and the backward path machining have the same cutting conditions, a uniform machined surface can be obtained. However, the removal of the uncut portion generated in the feed direction is not considered.

  In the above-mentioned Patent Document 3, in order to finish a deep vertical wall surface (elevation surface) or the like, a throw-away tip having one side of a substantially equilateral triangular plate shape as a front blade and the other side as an outer peripheral blade is mounted. A cutting cutter for cutting, for example, a cutting cutter for cutting with a front blade on one side and a peripheral blade on the other side while reciprocating is disclosed. The shape of the chip and the like for improving the strength is not disclosed.

In the above-mentioned Patent Document 4, a main cutting edge extending from one corner toward the other corner is formed in an insert having a substantially polygonal plate shape and having a cutting edge on the ridge line of the upper surface facing the seating surface. There is disclosed an insert provided with a first main cutting edge and a second main cutting edge provided with an obtuse angle protruding outward from the first main cutting edge in plan view. ing. Furthermore, the first main cutting edge is inclined so that the distance from the seating surface gradually decreases in a side view toward the second main cutting edge, that is, the upper surface that becomes a rake face is in the side view. The first ridge line scoop surface is inclined so that the distance from the main cutting edge to the seating surface gradually decreases in the central direction.
However, since the insert disclosed in Patent Document 4 performs the cutting process in the forward path and the backward path of the longitudinal feed processing, the finishing process is performed by the cutting process in the return path particularly on the machining surface cut in the forward path. There is no special cutting edge for the return trip. Therefore, the insert disclosed in Patent Document 4 does not include a cutting edge for performing a finishing process in the backward path cutting on the processed surface cut in the forward path.

In the above-mentioned Patent Document 5, a cutting edge having an arcuate corner blade is formed on the rake face of the rake face of the insert having a polygonal shape at the corner of the rake face. An insert with a configuration that suppresses the occurrence of crater wear on the rake face by forming a stepped portion where the rake face becomes lower on the way to the inside of the rake face from the tip P of the corner blade so as to intersect the corner blade. Is disclosed.
However, the insert disclosed in Patent Document 5 is similar to Patent Document 4 described above, when cutting is performed in the forward path and the backward path of vertical feed processing, particularly for the machining surface cut in the forward path. It does not have a cutting edge dedicated to the return path for finishing by cutting.

  In Patent Document 6 described above, a polygonal flat plate shape is formed, a corner blade is formed at at least one corner, and a tip is a corner blade at at least one ridge line portion connected to the corner where the corner blade is formed. A throw-away tip in which a continuous main cutting edge is formed, wherein the tip is continuous with the main cutting edge on the rear end side of the main cutting edge, and gradually tilts inward toward the rear end side. A throwaway tip having a configuration in which a second relief blade is formed on the rear end side of the first relief blade and is inclined outward with respect to the first relief blade is disclosed. Has been.

  The first relief blade provided in the throw-away tip disclosed in Patent Document 6 is configured to be inclined inward in the radial direction of the tool main body. This configuration improves chip discharge. It is provided for the purpose of cutting in the forward path and the return path of the longitudinal feed processing, especially for the return path for finishing the cutting surface in the return path for the machining surface cut in the forward path. Not a cutting edge.

  Therefore, an object of the present invention is to perform cutting in the forward path and the return path of vertical feed processing when a vertical hole or a vertical wall is cut in the work material by vertical feed using a rotary cutting tool with replaceable blade edge. In particular, in the return path cutting, it is possible to perform finishing with high accuracy on the machined surface cut in the outward path, and to improve the tool life, and to insert the insert into the tool body. An object of the present invention is to provide a blade-cutting-type rotary cutting tool that is detachably mounted on an insert mounting seat.

  The invention according to claim 1 of the present invention has a polygonal flat plate shape, and includes an upper surface portion, a lower surface portion formed at a position facing the upper surface portion and serving as a seating surface, and the upper surface portion and the lower surface portion. A side surface portion to be connected, a cutting edge for cutting, and a set screw hole are provided, and at least two corner portions among the corner portions formed at the ridge line portion between the upper surface portion and the side surface portion are arc-shaped corner portions. An insert provided with a corner blade in the corner portion, and in a state where the insert is mounted on a tool body, the insert is a cutting blade disposed on an outer peripheral side of the tool body, The main cutting edge connected to the outer peripheral end (t1) and the scooping of the main cutting edge from the other outer peripheral end (t3) of the main cutting edge toward the center of the upper surface portion. Formed with a length L along the edge of the surface And a rake face of the main cutting edge is formed as a rake face that serves as the rake face of the corner edge and the cutting edge for the backward path machining. The height formed by the rake face of the cutting edge with respect to the lower surface part is formed so as to be higher than the central part of the upper surface part or the vicinity of the central part. A flank face formed so as to descend from the rake face of the main cutting edge toward the upper surface part is provided.

  Invention of Claim 2 of this invention is the ridgeline part which the rake face and the said side part of the said main cutting edge make, Comprising: For the outward process connected to the other edge part (t2) of the said corner blade A second sub-cutting edge is provided.

The invention according to claim 3 of the present invention relates to the longitudinal feed insert for forward path and backward path processing according to claim 1 or claim 2, wherein the upper surface portion includes a rake face of at least two of the main cutting edges. , With a planar upper surface,
The rake face of the main cutting edge is an inclined surface that is inclined from the corner portion toward the planar upper surface portion.

  The invention according to claim 4 of the present invention relates to the longitudinal feed insert for the forward path and the backward path machining according to any one of claims 1 to 3, wherein the rake face of the main cutting edge is a stepped wall surface. It is set as the structure connected to the said planar upper surface part, and the relief surface of the said 1st subcutting edge for a backward path process is connected to the said level | step difference standing wall surface, It is characterized by the above-mentioned.

  According to a fifth aspect of the present invention, there is provided the longitudinal feed insert for forward path and backward path processing according to any one of the first to fourth aspects, wherein the insert has the upper surface portion and the side surface as viewed from above. Among the ridge lines formed by the section, a pair of opposite ridge lines is a long side and the other pair of ridge lines facing each other is a short parallel side. It is characterized by having a configuration with blades.

  The invention according to claim 6 of the present invention relates to the longitudinal feed insert for forward path and backward path processing according to any one of claims 1 to 5, wherein the set screw hole has a planar shape of the upper surface portion. It is characterized by being formed as a through hole penetrating from the upper surface portion to the lower surface portion or a through hole penetrating between the pair of side surface portions facing the center of the upper surface portion.

  The invention according to claim 7 of the present invention is a blade edge replacement in which the forward feed and the backward feed vertical feed insert according to any one of claims 1 to 6 are detachably attached to an insert mounting seat of a tool body. In the state where the longitudinal feed insert is mounted on the tool body, the main cutting edge provided on the ridge line portion of the long side is disposed on the outer peripheral side of the tool body. Yes.

The present invention can achieve the following effects.
The insert of the present invention having a polygonal plate shape that is detachably attached to the tool body includes a corner blade formed at the ridge line portion of the upper surface portion, a main cutting blade formed by connecting to the corner blade, and the insert as the tool body. The main cutting edge is mounted so as to be positioned on the outer peripheral side of the tool main body when mounted on the first end for the backward path processing formed in the direction of the center of the insert from the outer peripheral end of the main cutting edge. The corner blade, the main cutting edge, and the first sub cutting edge for return path machining are formed as a common rake face while having a configuration including a sub cutting edge. Further, the common rake face has a configuration in which the height from the lower surface portion is larger than the central portion of the upper surface portion.
This makes it possible to set the clearance angle of the flank face of the main cutting edge and the clearance angle of the first secondary cutting edge for return path machining to a sufficiently large value, so that the strength of these cutting edges can be ensured. In addition, the cutting resistance can be reduced. As a result, when cutting the workpiece in the forward path and the return path of the longitudinal feed processing with the cutting edge exchange type rotary cutting tool equipped with the insert of the present invention, the processed surface cut in the forward path is finished in the return path. It becomes possible to carry out the machining, and it is possible to improve the accuracy of the finished surface and improve the life of the cutting edge.

(A) is the perspective view which shows the embodiment about the blade-tip-exchange-type rotary cutting tool of this invention, (b) is the front view of the front-end | tip part seen from the rotation-axis center direction about the blade-tip-exchange-type rotary cutting tool shown to (a). It is. It is a top view for demonstrating the structure of 1st Embodiment of the insert which concerns on this invention. It is the front view which looked at the insert shown in FIG. 2 from the side surface part direction of a long side. It is the front view which looked at the insert shown in FIG. 2 from the side part part direction of a short side. It is the perspective view which looked at the insert shown in FIG. 2 from diagonally upward of the upper surface part. The state when the workpiece is cut in the forward path of the longitudinal feed process and the forward path of the longitudinal feed process when the workpiece is cut by the forward path of the longitudinal feed process and the return path by the cutting edge exchange type rotary cutting tool of the present invention shown in FIG. 1 will be described. FIG. Similarly, when the workpiece is cut in the forward path and the backward path of the longitudinal feed by the cutting edge exchange type rotary cutting tool of the present invention shown in FIG. It is a figure for demonstrating. (A) is a figure which shows an example of the movement locus | trajectory of this blade-tip-exchange-type rotary cutting tool in the cutting using the tip-exchange-type rotary cutting tool of this invention, (b) is a tip-exchange-type rotary cutting tool of a prior art example. It is a figure which shows the movement locus | trajectory when used. It is a top view about the blade edge | tip-exchange-type rotary cutting tool of this invention, and is a figure explaining the cutting angle (kappa) of the 1st subcutting blade for a backward path | route process. It is a side view about the blade edge | tip exchange-type rotary cutting tool of this invention, and is a figure explaining clearance angle (alpha) of the 1st subcutting blade for a backward path | route process. It is a side view about the blade edge | tip exchange-type rotary cutting tool of this invention, and is a figure explaining the axial rake angle (gamma) of a main cutting edge. It is a top view for demonstrating the structure of 2nd Embodiment of the insert which concerns on this invention. It is the side view which looked at the insert shown in FIG. 12 from the side part direction of a long side. It is the front view which looked at the insert shown in FIG. 12 from the side part part direction of a short side. It is the perspective view which looked at the insert shown in FIG. 12 from diagonally upward of the upper surface part. It is a perspective view for demonstrating the structure of 3rd Embodiment of the insert which concerns on this invention. It is a perspective view for demonstrating the structure of 4th Embodiment of the insert which concerns on this invention.

  When a mold or the like is manufactured by cutting, it is necessary to process a vertical hole or a standing wall in the mold material using a rotary cutting tool. The present invention has a polygonal flat plate shape when the vertical hole or the vertical wall is processed by vertical feed processing of a rotary cutting tool, and includes a cutting blade for performing cutting processing in the forward and backward paths of the vertical feed processing. An insert that can perform finishing on the machined surface cut in the forward path, particularly in the return path cutting of the longitudinal feed process, and the insert can be freely attached to and removed from the insert mounting seat of the tool body. It is a cutting edge exchangeable rotary cutting tool that is mounted. Note that the polygon means that the insert has a triangular shape, a substantially triangular shape, a substantially rectangular shape, a substantially parallelogram shape, a pentagonal shape or a substantially pentagonal shape, a hexagonal shape or a substantially hexagonal shape, or the like.

  Hereinafter, embodiments of the present invention will be described. Fig.1 (a) is a perspective view which shows the embodiment about the blade-tip-exchange-type rotary cutting tool (1) based on this invention, Comprising: Two insert mounting seats (2) formed in the front-end | tip part of a tool main body (2) Each of 3) shows a state in which the insert (5) provided with the cutting edge of the present invention is detachably mounted using a clamp screw (set screw) (4). The insert (5) has a substantially parallelogram in a top view. FIG.1 (b) is a front view of the front-end | tip part which looked at the blade-tip-exchange-type rotary cutting tool (1) shown in Fig.1 (a) from the rotation axis O direction.

(First embodiment of the insert)
First, the structure of 1st Embodiment is demonstrated based on FIGS. 2-5 about the vertical feed insert for a forward path and a backward path | route process based on this invention. 2 is a plan view of the longitudinal feed insert (5) for processing the forward path and the backward path, FIG. 3 is a side view of the insert (5) seen from the long side, and FIG. 4 is a plan view of the insert (5) from the short side. FIG. 5 is a front view, and FIG. The insert (5) according to the first embodiment has a substantially parallelogram shape when viewed from above and has a plate shape. For example, the length of the long side is 8 mm, the length of the short side is 4 mm, and the thickness is 2 mm. This is particularly effective when applied to small inserts of the order. In the following description, the longitudinal feed insert for the forward path and the backward path machining according to the first embodiment is simply referred to as “insert (5)”.

  The material of the substrate constituting the insert (5) includes, for example, Co or Ni in addition to tungsten carbide (WC), and further, if necessary, titanium (Ti), tantalum (Ta), neodymium (Nb) A hard phase mainly containing titanium carbide (TiC), titanium nitride (TiN), titanium carbonitride (TiCN), etc. It can be composed of a cermet composed of a binder phase mainly composed of an iron-based metal such as cobalt (Co) or nickel (Ni). The insert (5) is produced by pressing the above-mentioned cemented carbide or cermet fine powder into a suitable shape after pressing the insert powder compact with a press molding machine using a mold. A hard sintered compact can be obtained by firing at a temperature for a predetermined time. And about this sintered compact, insert (5) can be manufactured by processing a cutting edge part etc.

  As shown in FIGS. 2 to 5, the insert (5) includes an upper surface portion (6), a lower surface portion (7) formed at a position facing the upper surface portion (6), an upper surface portion (6), and a lower surface portion. A pair of side surface portions (8a, 8a) connecting (7) and another pair of side surface portions (8b, 8b) are provided. The lower surface portion (7) serves as a bottom surface that is in close contact with the seating surface of the insert mounting seat (3) when the insert (5) is mounted on the insert mounting seat (3) of the tool body (2).

  As shown in FIG. 2, the upper surface portion (6) of the insert (5) has a substantially parallelogram shape (substantially parallelogram shape) in a top view. The ridge line portion formed by the upper surface portion (6) and the side surface portions (8a) and (8b) having a substantially parallelogram shape is a ridge line portion (9a, 9b) that is a long side and a ridge line that is a short side. Part (10a, 10b) is formed. Furthermore, a set screw hole (11) penetrating the insert (5) from the upper surface portion (6) to the lower surface portion (7) is provided in the central portion of the upper surface portion (6). The set screw hole (11) is a hole through which the clamp screw (4) is inserted when the insert (5) is detachably mounted on the insert mounting seat (3) of the tool body (2).

As shown in FIG. 2, the corner portion of the upper surface portion (6) where the ridge line portion (9a) which becomes the long side and the ridge line portion (10b) which becomes the short side intersect, and the ridge line portion (9b) which becomes the long side. Corner portions (12a) and (12b) each having an arc shape are formed at corner portions of the upper surface portion (6) where the ridge line portion (10a) serving as the short side intersects. And the corner blades (13a) and (13b) having an arc shape are formed in the ridge line portion formed by the corner portions (12a and 12b) and the side surface portions, and the pair of corner blades (13a) and (13b) These are arranged at positions symmetrical to the set screw hole (11).
In addition, in the following description, when showing a pair of corner parts (12a) and (12b), a corner part (12a, b), and when showing a pair of corner blades (13a) and (13b), a corner edge (13a, b) ).

  In addition, as shown in FIG. 2, the other pair of corners (12c) and (12d) arranged at positions symmetrical to the set screw hole (11) are ridge lines (long lines) ( 9a) is a corner portion where the ridge line portion (10a) which is the short side intersects at an obtuse angle, and a corner portion where the ridge line portion (9b) which is the long side intersects with the ridge line portion (10b) which is the short side intersects at an obtuse angle.

  As shown in FIGS. 2 and 3, the surface from the corner (12a, b) of the upper surface (6) toward the central portion (set screw hole 11) of the upper surface (6) is the lower surface (7). Inclined planar rake surfaces (14a) and (14b) are formed which gradually decrease in height (distance) from the corners (12a, b) toward the center of the upper surface (6). Yes. In the following description, when a pair of rake faces (14a) and (14b) are shown, they may be referred to as rake faces (14a, b).

  The ridge line portions (9a) and (9b) on the long side of the rake face (14a, b) are respectively linear mains integrally connected to one end (t1) of the corner blade (12a, b). Cutting edges (15a) and (15b) are provided up to (t3) point. The rake face (14a) is a rake face (main cutting edge rake face) of the main cutting edge that serves as the rake face of the corner edge (12a) and the rake face of the main cutting edge (15a), and the rake face (14b). Is the rake face of the main cutting edge which also serves as the rake face of the corner edge (12b) and the rake face of the main cutting edge (15b). In the following description, when a pair of main cutting edges (15a) and (15b) are shown, they may be described as main cutting edges (15a, b).

  As described above, the rake face (14a, b) has a configuration in which the rake face is gradually inclined from the corner part (12a, b) toward the center part of the upper face part (6). As shown in FIG. 3, side surface portions (8a1) and (8a1) are provided between the side surface portion (8a) and the main cutting edges (15a) and (15b). As shown in FIG. 3, the rake face (14a, b) inclines the angle θ3 (degree) with respect to the lower surface portion 7 in the range of “5 ≦ θ3 ≦ 9”. A straight line P7 shown in FIG. 3 is a straight line along the main cutting edges (15a) and (15b) in a side view of the insert (5).

In the insert (5), the second secondary cutting edge (16a) for straight forward processing connected to the other end (t2) of the corner blade (12a) may be provided up to the point (t4). . Similarly, the second secondary cutting edge (16b) for straight forward machining connected to the other end (t2) of the corner edge (12b) may be formed up to the point (t4).
In the present invention, the corner blades (12a, b) are cutting blades used as a forward cutting edge, and the second auxiliary cutting edges (16a, 16b) are also used as outgoing cutting edges. It is a cutting edge that can be used. Since the corner blades (12a, b) are employed as the cutting edges for the outward processing, the cutting edge strength is high and the fracture resistance is excellent. It becomes possible.
In the following description, the pair of second sub cutting edges (16a) and (16b) may be described as the second sub cutting edges (16a, b).

As shown in FIG. 2 and FIG. 5, stepped wall surfaces (17 a) and (17 b) are respectively formed from ridge lines (14 a 1) and (14 b 1) which are ends of the upper surface portion 6 of the rake face (14 a, b). ), And the lower end portions of the stepped wall surfaces (17a) and (17b) are provided with a planar upper surface portion (18) connected to the lower end portion. The planar upper surface part (18) constituting the region including the central part of the upper surface part 6 (excluding the opening of the set screw hole 11) has the same height from the lower surface part (7), that is, the planar upper surface. The part (18) is formed to be parallel to the lower surface part (7). The planar upper surface portion (18) is formed as a plane including the peripheral portion of the opening of the set screw hole (11) and the corner portions 12c and 12d. The set screw hole (11) is formed through the insert (5) from the planar upper surface portion (18) to the lower surface portion (7).
In the following description, when a pair of stepped wall surfaces (17a) and (17b) are shown, they may be described as stepped wall surfaces (17a, b).

  In the insert (5), as shown in FIG. 2 (FIG. 5), a ridge line portion formed by the planar upper surface portion (18) including the corner portions (12c) and (12d) and the side surface portions (8a) and (8b). There is no need to provide a cutting edge.

  Further, as shown in FIG. 2, the stepped wall surfaces (17a, b) are composed of a ridge line part (10b) on the short side of the rake face (14a, b), an end part (t5) of (10a), and a long side. From the edge ridgelines (14a1) and (14b1) connecting the edge portions (t6) of the rake face (14a, b) in the vicinity of the ridgeline portions (9a) and (9b) of the planar upper surface portion (18 ). The shape of the stepped wall surfaces (17a, b) is preferably a shape that gently protrudes into a convex shape. The stepped wall surfaces (17a, b) shown here are an example of an embodiment of an inclined surface inclined from the rake face (14a, b) of the main cutting edge toward the planar upper surface portion (18).

  In the insert (5) of the present invention, as shown in FIG. 2, the end (t3) of the main cutting edge (15a, b) and the end (t6) of the rake face (14a, b) are connected. First straight cutting edges (19a) and (19b) for return path processing are provided on the linear ridge line portions having the length L, respectively. As described above, the end portions (t3) of the main cutting edges (15a, b) are connected to the first sub cutting edges (19a), (19b) for return path machining, respectively.

Furthermore, flank faces (20a) and (20b) descending toward the planar upper surface portion 18 are provided on the first auxiliary cutting edges (19a) and (19b) for the backward path processing, respectively. These flank faces (20a) and (20b) are ridge lines connecting the end portions (or the end portions of the main cutting edges (15a, b)) (t3) and the end portions (t6) of the rake face (14a, b). And a stepped wall surface that connects the planar upper surface portion 18 and is provided as a flank for the first auxiliary cutting edges (19a) and (19b) for return path processing. Further, the end portions of the clearance surfaces (20a) and (20b) in the direction of the set screw hole (11) and the vicinity thereof are formed so as to intersect the stepped wall surfaces (17a and b), respectively. Since the first sub cutting edges (19a) and (19b) for the return path processing have the linear cutting edge ridge line portion, the cutting resistance can be reduced and the sharpness is also good. It has a shape suitable for performing finishing in the processing.
In the following description, when a pair of first sub-cutting edges (19a) and (19b) is shown, a first sub-cutting edge (19a, b) and a pair of flank faces (20a) and (20b) are shown. It may be described as a flank (20a, b).

  The length L (mm) of the first sub cutting edge (19a, b) for the backward path processing is 0.03F ≦ L ≦, where the distance between the long sides of the insert (5) is the reference value F (mm). It is preferable to set to be 0.25F. This is to reduce the burden on the cutting edge by setting the length of the first sub-cutting edge (19a, b) for backward path processing to the minimum necessary. As a result, an increase in cutting resistance can be suppressed, and defects such as defects can be avoided. It is also effective for securing the strength of the insert (5). Here, the reference value F (mm) preferably has a range of 4 mm or more and 12 mm or less.

  The reason why the length L value of the first sub-cutting edge (19a, b) for the return path machining is in the above range is that when it is less than 0.02F, the machining allowance by the cutting process cannot be secured sufficiently, so the machining efficiency This is because inconvenience such as inferiority occurs. In a normal general example, the machining allowance by cutting is set to at least about 0.1 to 0.2 (mm). Therefore, the L value is preferably set longer than the above value. More preferably, the L value is set to about 0.4 (mm) corresponding to twice the machining allowance of 0.2 (mm). On the other hand, when the L value exceeds 0.25 F and is long, the end of the return cutting edge (19a, b) may be deteriorated in strength due to interference with the set screw hole. Therefore, it is preferable to set the L value smaller than 0.25F.

In the above-described insert (5) according to the present invention, the first sub-cutting blade (19a, b) for return path processing is mounted longitudinally on the insert (5) on the blade-tip-exchange-type rotary cutting tool (1). When cutting is performed on the forward path and the backward path by machining, the cutting edge is provided as a cutting edge for performing a finishing process on the work surface of the work material cut on the forward path, particularly in the cutting process on the backward path. For this purpose, the end portion (t3) that connects the main cutting edge (15a, b) and the first sub cutting edge (19a, b) for return path processing has a long side in the plan view of the insert (5). It is necessary to make it protrude slightly from the ridgeline part (9a, b) which becomes the outer side of the insert (5).
In order to realize this, when designing the shape of the insert mounting seat (3) of the tool body (2), a linear main cutting edge (15a) formed from the end (t1) to the end (t3). B) may be formed so as to slightly protrude from the end portion (t1) toward the outer side of the insert (5) with respect to the ridge line portions (9a) and (9b) which are long sides.

  As shown in FIG. 3, the inclination angle θ2 (degree) in the thickness direction of the flank (20a, b) of the first sub-cutting blade (19a, b) for the backward path processing is 0 <θ2 ≦ 10. It is desirable to set. Further, the rake face (14a, b) of the main cutting edge also serves as the rake face of the first auxiliary cutting edge (19a, b) for backward path machining. The straight line P5 shown in FIG. 3 is a straight line extending from the end (t3) of the first auxiliary cutting edge (19a, b) along the flank surfaces (20a), (20b) in the side view of the insert 5. The straight line P6 is a straight line orthogonal to the lower surface part (7) in a side view of the insert (5), and the angle formed by the straight line P5 and the straight line P6 is the inclination angle θ2.

  By setting the inclination angle θ2 of the first sub-cutting edge (19a, b) for backward path processing to the above-mentioned “0 degree <θ2 ≦ 10 degrees”, it is effective to stabilize the wear form of the cutting edge. The progress of wear can be normal wear. When the θ2 value is 0 degree, it is inconvenient because the draft angle of the mold cannot be obtained when the powder molded body of the insert (5) is formed by press working using the mold. If the angle is greater than 10 degrees, the design margin of the seating surface of the tool body is reduced in order to adjust the clearance angle of the cutting edge when this insert is mounted on the tool body, and the insert mounting seat This is inconvenient because it is difficult to set the back metal sufficiently thick to ensure the strength of (3).

  The direction of the first sub cutting edge (19a, b) for the backward path machining having the length L described above is such that the end (t3) and the end (t6) are in a plan view of the upper surface portion 6 shown in FIG. The connecting line segment P3 passes through the center line P0 of the set screw hole (11) and is set to intersect with the straight line P4 perpendicular to the longitudinal center line P1 of the insert (5) at an angle θ1. Is desirable. A straight line P2 shown in FIG. 2 is a straight line that passes through the center line P0 of the set screw hole (11) and is orthogonal to the straight line P1 in a plan view of the insert (5).

Since this angle θ1 affects the cutting angle κ of the first auxiliary cutting edge (19a, b) during the backward path machining shown in FIG. 9, it is desirable to set −10 degrees ≦ θ1 ≦ 45 degrees. A more preferable angle θ1 is 30 degrees. On the other hand, when the angle θ1 exceeds 45 degrees, the length at which the cutting edge comes into contact with the work material is increased during the return path machining, the cutting resistance from the tool radial direction is increased, and the tool vibrates. Therefore, it is inconvenient, and if it is less than −10 degrees, the strength of the cutting edge is lowered and the possibility of a defect is increased.
When the angle θ1 is a positive value, the first sub cutting edge (19a, b) is tilted away from the second sub cutting edge (16a, b), and when the angle θ1 is a negative value. The first sub-cutting edge (19a, b) is inclined toward the second sub-cutting edge (16a, b).
In addition, the cutting angle κ shown in FIG. 9 is the same as the straight line P8 orthogonal to the rotation axis O in the plan view of the blade-tip replaceable rotary cutting tool (1) and the same in the plan view of the blade-tip replaceable rotary cutting tool (1). It is an angle formed by the straight line P9 along the one sub cutting edge (19a, b).

  The main insert (5) according to the first embodiment of the present invention, which has a substantially parallelogram flat plate shape as viewed from above and performs the cutting process in the forward path and the return path of the vertical feed cutting process, is provided. Features are as described in Features 1 and 2 below.

(Feature 1)
A two-corner type insert (5) having a substantially parallelogram in top view and having two corner portions (12a, b) includes a corner blade (13a, b) and a linear main cutting edge (15a, b) and a first auxiliary cutting edge (19a, b) for return path machining. Moreover, you may provide the 2nd sub cutting edge (16a, b) for an outward process as needed.
The first sub-cutting edge (19a, b) for return path processing is connected to one end (t3) of the linear main cutting edge (15a, b), and the end screw (t3) is connected to the set screw. It has a length L in the direction of the angle θ1 with respect to the straight line P4 perpendicular to the center line P1 in the longitudinal direction of the insert (5) in the plan view of the upper surface portion 6 in the direction of the hole (11). The flank (20a, b).

  In the insert according to the present invention, the first characteristic of the structure is that, among the above-mentioned cutting edges, in particular, a first sub cutting edge (19a, b) for return path machining is provided. As a result, when cutting is performed in the forward path and the backward path of the longitudinal feed by the cutting edge exchange type rotary cutting tool (1) equipped with the insert (5) of the present invention, the cutting is performed in the forward path in the backward path cutting. It is possible to perform finishing on the processed surface. The effect of performing the finishing process of the machined surface cut in the outward path in the return path cutting will be described later.

(Feature 2)
The rake face (14a, b) of the main cutting edge that constitutes the upper surface part (6) of the insert (5) has a height from the lower surface part (7), and a region including the central part of the upper surface part (6). It is formed so as to be higher than the height of the planar upper surface portion (18) to be formed. Thereby, in particular, the clearance angle of the side surface portion (8a1, 8b1) that becomes the flank surface of the main cutting edge (15a, b) and the inclination angle in the thickness direction of the first sub cutting edge (19a, b) for return path machining. It is possible to set the clearance angle α (see FIG. 10) of the flank (20a, b) of the first secondary cutting edge (19a, b) for return path machining, which is set according to the setting of θ2, to a sufficiently large value. Therefore, it is possible to secure the strength of the main cutting edge (15a, b) and the first sub cutting edge (19a, b) for backward processing, and it is possible to reduce the cutting resistance. As a result, it is possible to improve the accuracy of the work surface of the work material and the life of the blade-tip-exchange-type rotary cutting tool (1) equipped with the insert (5).

Here, although the inclination angle θ2 in the thickness direction of the first sub cutting edge (19a, b) for the backward path processing has been described above, the end portion (t3) in the side view of the insert (5) as shown in FIG. ) Is set by an angle at which a straight line P5 extending from the lower surface portion (20a, b) to the upper surface portion (6) intersects the straight line P6 orthogonal to the lower surface portion (7).
Further, the clearance angle α of the flank (20a, b) of the first secondary cutting edge (19a, b) for return path machining shown in FIG. 10 is a rotational axis in a side view of the blade tip replaceable rotary cutting tool (1). A straight line P8 orthogonal to the center O and a straight line P10 along the flank (20a, b) of the first auxiliary cutting edge (19a, b) in the same side view of the cutting edge exchange type rotary cutting tool (1) are formed. Is an angle.

  Subsequently, the above-mentioned insert (5) is mounted on the insert mounting seat (3) of the cutting edge exchange type rotary cutting tool (1) shown in FIG. The operation when performing the above will be described.

One of the main cutting edges (15a, b) of the insert (5) when the insert (5) is attached to the insert mounting seat (3) of the blade-tip-exchange-type rotary cutting tool (1) by tightening the clamp screw (4). Is slightly protruded outward from the outer peripheral surface of the insert mounting seat (3) of the blade-tip-exchange-type rotary cutting tool (1). Also, one of the corner blades (13a, b) is slightly protruded outward from the tip surface of the insert mounting seat (3) of the blade-tip-exchange-type rotary cutting tool (1).
Furthermore, when the second sub cutting edge (16a, b) is provided, one of the second sub cutting edges (16a, b) is also provided on the insert mounting seat (3) of the blade tip replaceable rotary cutting tool (1). It protrudes slightly outward from the tip surface.

Although not shown in FIG. 1, when the insert (5) is fixed to the insert mounting seat (3) by fastening the clamp screw (4), the adjacent insert (5) is not shown in FIG. ) Is provided with a constraining wall surface part for constraining the side surface parts (8a, 8b).
Moreover, the axial rake angle γ value of the main cutting edge of the insert (5) when the insert (5) is mounted on the tool body (2) is a positive value of 13 to 18 degrees as shown in FIG. Set within the range. 1 (a), 6, 7, 9, 10, and 11, reference numeral R denotes the rotation axis of the blade-tip-exchange-type rotary cutting tool (1) when cutting a work material. The direction of rotation with respect to O is shown. In addition, the straight line P11 shown in FIG. 11 has shown the straight line along the main cutting edges (15a, b) by the side view of a blade-tip-exchange-type rotary cutting tool (1).

  FIGS. 6 and 7 illustrate a longitudinal feed forward path in which the cutting edge replaceable rotary cutting tool (1) is in the direction of the rotation axis O by the cutting edge replaceable rotary cutting tool (1) having two inserts (5) mounted thereon. When the vertical wall is cut on the work material (M) by vertical machining that feeds in the F1 direction, which is the cutting (outward machining), and in the F3 direction, which is the backward machining (returning). It is a figure which shows a state.

  In the forward cutting shown in FIG. 6, the cutting of the vertical wall surface is performed while the blade tip exchange-type rotary cutting tool (1) is vertically fed in the F1 direction, the main cutting edge (15a) of the insert (5), and the corner blade. (13a) is used for processing. Further, when the insert (5) is also provided with the second auxiliary cutting edge (16a), the forward cutting is performed using the main cutting edge (15a), the corner cutting edge (13a) and the second auxiliary cutting edge (16a). Can be implemented. In this forward cutting, rough machining of the standing wall surface (m1) of the work material (M) is completed by controlling the cutting edge exchange type rotary cutting tool (1) to be sent in the F1 direction.

Next, as shown in FIG. 7, the cutting edge exchange type rotary cutting tool (1) is processed by controlling the feed in the F3 direction which is the cutting process of the return path. In the cutting process in the F3 direction, a finished cutting surface (m3) is obtained by performing a finishing cutting process on the rough wall surface (m1).
When the vertical feed in the F3 direction is started, cutting with a predetermined finishing allowance is performed on the vertical wall surface (m1) cut by the main cutting edge (15a) during the vertical feed in the F1 direction shown in FIG. The return feed (feed in the F3 direction) of the blade-tip-exchange-type rotary cutting tool (1) is controlled so that the finished processed surface (m3) is obtained after being processed.

  FIG. 7 shows a rough machining vertical wall surface (m1) from the bottom surface (m2) of the work material (M), and a vertical wall in the range from the bottom surface (m2) to the height H1 as a finishing surface (m3). It shows the state that was done. In the return path machining by feeding in the F3 direction, the finishing wall surface of the rough wall surface (m1) is finished by the main cutting edge (15a) and the first auxiliary cutting edge (19a) for the backward path processing. Is done.

In the finishing process by feeding the return path in the F3 direction shown in FIG. 7, the main cutting edge (15a) and the first sub cutting edge (19a) for the return path process become cutting edges that contribute to this finishing cutting process. In the finish cutting of the return path, the first auxiliary cutting edge (19a) for the return path processing becomes a cutting blade for cutting the standing wall surface (m1) by a predetermined finishing allowance.
At this time, although it is finishing, a cutting resistance acts on the first sub-cutting edge (19a). In the insert (5) of the present invention, the first auxiliary cutting edge (19a, b) for backward path processing includes the flank (20a, b) as described above. Since the inclination angle θ2 in the thickness direction of the first auxiliary cutting edge can ensure a sufficiently large value, the cutting resistance can be reduced, and the strength of the first auxiliary cutting edge (19a, b). Can be improved. The inclination angle θ2 (degrees) is desirably set to 0 <θ2 ≦ 10 as described above.

  In the finishing process by feeding in the F3 direction (return path) shown in FIG. 7, the main cutting edge (15a) has a higher-accuracy finishing process on the processed surface cut by the above-described return path cutting edge (19a). It works to process the surface.

  FIG. 8 (a) is a rotary cutting tool when the longitudinal cutting shown in FIGS. 6 and 7 is carried out on the work material (M) using the cutting edge replaceable rotary cutting tool (1) of the present invention. An example of the movement locus of (1) is shown. In FIG. 8 (a), the cutting edge-replaceable rotary cutting tool (1) according to the present invention is cut while the vertical machining for feeding in the F1 direction as the longitudinal feed path and the F3 direction as the return path is repeated. It is a figure which shows an example when the state which is cutting the standing wall surface to a material (M), ie, the cutting process of the forward path of a longitudinal feed, and a return path is implemented.

  In the vertical machining in the example of the present invention, first, the forward machining (K1) in the F1 direction is performed, and the workpiece (M) is roughly machined to obtain the standing wall (m1). At the end of the forward machining (K1), the blade-tip-replaceable rotary cutting tool (1) is moved in the direction F2 perpendicular to the direction of the rotation axis O and parallel to the standing wall. The amount of movement at this time is half the width of the feed direction cut width (see FIG. 8A).

  Next, the exchangeable rotary cutting tool (1) performs the return path processing (K2) in the F3 direction, finishes the work material (M), forms the finished vertical wall surface (m3), and then performs the return path processing (K2). At the end of, the blade-tip-exchange-type rotary cutting tool (1) is moved in a direction perpendicular to the rotation axis direction and in the F4 direction parallel to the standing wall surface. The amount of movement at this time is a width corresponding to 1.5 times the feed direction cut width. Thereafter, the forward process (K3) in the F1 direction, which is the forward path, is started again. At this time, the movement in the F4 direction is a feed direction for proceeding with the original processing, and conversely, the F2 direction is opposite to the F4 direction.

  The longitudinal feed forward path / return path cutting process is defined as one cycle. That is, the movement of the exchangeable rotary cutting tool (1) is one cycle of movement in the direction of F1-> F2-> F3-> F4. At that time, the machining cycle is repeated, such as forward machining (K1) → return machining (K2) → forward machining (K3) → return machining (K4) → forward machining (K5) → return machining (K6). Thus, a finished standing wall surface (m3) of the work material (M) can be obtained.

  The feed control of the blade-cutting-type rotary cutting tool (1) in the F1, F2, F3, and F4 directions is mounted on a three-dimensional control machine tool or the like on which the shank portion of the rotary cutting tool (1) is mounted and fixed. It is executed according to the control of the NC program.

On the other hand, FIG. 8B shows a movement locus when the conventional cutting process described in Patent Document 2 or the like is performed on the movement locus of the rotary cutting tool.
In this conventional example, the forward feed machining (K1) of the longitudinal feed is performed, and at the end of the forward feed machining (K1), the feed moves in the direction perpendicular to the rotational axis direction and parallel to the vertical wall by the feed direction cut width. Let Thereafter, the return path machining (K2) is started, and cutting is performed to the end of the backward path machining (K2). The machining conditions at both times are the same, and the standing wall is cut by repeating this machining cycle a plurality of times while sequentially moving by the feed direction cut width. However, at this time, an uncut portion is generated as shown in FIG. When the cutting process shown in FIG. 8A is performed, an uncut portion is not generated.

(Example of cutting)
A cutting test of vertical side surface processing using S50C material as a work material was performed. The cutting edge exchange type rotary cutting tool of the present invention used for this cutting test has a tool diameter of 10 mm, and the mounted insert according to the present invention is an insert having a two-corner type substantially parallelogram shown in FIGS. 5) was used as a two-blade replaceable rotary cutting tool equipped with two sheets. The inserted insert was made of cemented carbide made of WC-Co base, the long side length was 8 mm, the short side length was 4 mm, and the thickness was 2 mm. The cutting conditions of the cutting test are the following cutting conditions 1 and 2 for the forward path machining and the backward path machining, and the reciprocal path of the longitudinal feed to the work material with the movement trajectory of the blade cutting type rotary cutting tool shown in FIG. The cutting process was carried out. The length of the longitudinal feed at which cutting was performed at this time was 100 mm, and the processing length in the feed direction was 150 mm.

(Cutting condition 1)
The cutting condition 1 is a cutting condition for an outward process in which roughing is performed.
・ Cutting speed: 200 m / min
・ Spindle speed: 6366 min-1
・ One blade feed: 0.1 mm
・ Table feed: 1273 mm / min
・ Cutting width in feed direction: 1mm
・ Diameter cut width: 1mm
・ Processing method: Dry cutting

(Cutting condition 2)
The cutting condition 2 is a cutting condition for the return path processing for finishing.
・ Cutting speed: 300 m / min
・ Spindle speed: 9549 min-1
・ One blade feed: 0.1 mm
-Table feed: 1910 mm / min
・ Cutting width in feed direction: 1mm
・ Processing method: Dry cutting

According to the longitudinal feed cutting tool for forward / rearward machining according to the present invention, after roughing, a longitudinal feed width is given by the backward machining to process the uncut portion on the side surface formed by the forward machining. Since the processing method is also possible, the processed surface roughness of the standing wall surface after processing is good. In addition, it was possible to obtain a longitudinal feed cutting tool with high machining efficiency for forward / return machining.
In addition, by dividing the cutting edge involved in cutting into forward path processing and backward path processing, the cutting length that can be processed at one corner is long and the tool life is improved.

  The above-described longitudinal feed insert (5) for processing the forward path and the backward path according to the first embodiment of the present invention is a two-corner insert, that is, the upper surface portion (6) has a substantially parallelogram shape, and its two corners. The corner portion (12a, b) is the corner portion (12a) side, the corner blade (13a), the main cutting edge (15a), the first sub cutting edge (19a) for the return path processing, the second The sub-cutting edge (16a) is provided. When these cutting edges are worn and a predetermined processing accuracy cannot be obtained, the clamp screw (4) is loosened and the direction of the insert (5) is rotated 180 degrees to form the insert mounting seat (3). Cutting using the corner blade (13b) on the corner portion (12b) side, the main cutting edge (15b), the first sub cutting edge (19b), and the second sub cutting edge (16b) for return path machining after remounting. I do.

  Moreover, in 1st Embodiment of the vertical feed insert (5) for an outward path | route and a backward path | route process which concerns on this invention shown in above-mentioned FIGS. 2-5, it comprises a substantially parallelogram in top view, and an upper surface part (6 ) Comprises at least two rake faces (14a, b) of the main cutting edge and a planar upper surface part (18), the rake face (14a, b) of the main cutting edge from the corner part (12a, b). Although the example made into the inclined surface which inclines toward a planar upper surface part (18) was demonstrated, it is good also as an insert provided with the following structure.

  (1) That is, the rake face (14a, b) of the flat main cutting edge is formed so as to form a plane parallel to the lower surface part (7), and the rake face (14a, b) and the planar upper face part are formed. In order to interpolate the step with (18), as in the first embodiment, the stepped wall surface (17a, b) and the flank (20a, b) of the first auxiliary cutting edge (19a, b) are provided. Use the provided configuration.

  (2) In the first embodiment, the set screw hole (11) is configured to penetrate from the upper surface (6) to the lower surface (7) of the insert (5). It is good also as a structure penetrated from the one side part to the other side part facing this side part like the insert (5b) used as a form.

(Second Embodiment of Insert)
Next, a second embodiment of the longitudinal feed insert for forward and backward machining according to the present invention will be described with reference to FIGS. 12 is a plan view of the insert (5a) according to the second embodiment, FIG. 13 is a side view of the insert (5a) viewed from the side of the long side, and FIG. 14 is a long side of the insert (5a). FIG. 15 is a perspective view of the insert (5a) as viewed from obliquely above the upper surface portion.

The insert (5a) according to the second embodiment has the following configuration without providing the planar upper surface portion (18) included in the insert (5) according to the first embodiment shown in FIG. There is a special feature.
That is, the rake surfaces (14a) and (14b) of the main cutting edge are gradually extended from the corners (12a) and (12b) to the vicinity of the set screw hole (11), and the main cutting edge (15a). , (15b) from the end (t3) in the direction of the set screw hole (11), the first sub cutting edges (19a), (19b) for the backward processing are formed, and the first sub cutting for the backward processing is further formed. The blades (19a) and (19b) are provided with flank surfaces (20a) and (20b), respectively.

  Although not shown in FIG. 12, like the insert (5) of the first embodiment described above, the first sub-cutting blades (19a) and (19b) for return path machining having a length L are provided. The orientation is such that the line segment P3 connecting the end portion (t3) and the end portion (t6) passes through the center line P0 of the set screw hole (11) in the plan view of the upper surface portion 6, and the length of the insert (5a) It is desirable to set so as to intersect at an angle θ1 with respect to a straight line P4 orthogonal to the direction center line P1 (see FIG. 2). Furthermore, since this angle θ1 affects the cutting angle (κ) of the first sub-cutting edge (19a, b) during the backward path machining, it is desirable to set −10 degrees ≦ θ1 ≦ 45 degrees.

A straight line P5 shown in FIG. 13 is a straight line extending from the end (t3) of the first auxiliary cutting edge (19a) along the flank (20a) in the side view of the insert (5a). Similarly, the straight line P6 is the insert (5a). In the side view, the straight line and the angle (θ2) perpendicular to the lower surface portion (7) indicate the inclination angle in the thickness direction of the insert (5a) of the first sub-cutting blade (19a) for return path processing.
This inclination angle (θ2) is desirably set to 0 <θ2 ≦ 10 as in the case of the insert (5) in the first embodiment.

  The insert (5a) according to the second embodiment having the above-described configuration is not provided with the planar upper surface portion (18) provided in the insert (5) according to the first embodiment, so the insert (5a) ) Can be made larger, and the rigidity of the insert can be improved.

(Third embodiment of the insert)
FIG. 16: is a perspective view for demonstrating the structure of 3rd Embodiment about the longitudinal feed insert for the outward path | route of this invention, and a backward path | route process. The insert (5b) according to the third embodiment has a set screw hole (11) provided in the insert from one side surface portion (8a) to the other side surface portion of a pair of side surface portions facing the insert. It is characterized by being formed to penetrate to (8a). Moreover, each cutting edge is provided on both surfaces of the upper surface portion (6) and the lower surface portion (7) of the insert (5b), and has a double-sided insert configuration with four corners. That is, the insert (5b) according to the third embodiment is provided with two corner portions on each of the upper surface portion (6) and the lower surface portion (7), for a total of four corner portions. Is provided with a corner blade (13a, b), a main cutting blade (15a, b), a second sub cutting blade (16a, b), and a first sub cutting blade (19a, b) for backward processing. Yes. The rake faces (14 a) and (14 b) provided on the upper surface part (6) or the lower surface part (7) are formed to be higher than the planar upper surface part 18.

  In the insert (5b) according to the third embodiment, the set screw hole (11) is connected from one side surface portion (8a) to the other side surface portion (8a) of the pair of side surface portions of the insert. Since it penetrates, the pair of side surface portions (8a) and (8a) are formed so that the width in the short side direction is larger than the width in the short side direction of the upper surface portion (6) (or the lower surface portion (7)). doing.

  In addition, the constraining wall surface for mounting the insert (5b) in the third embodiment on the insert mounting seat of the tool body includes one side surface portion (8a) and a pair of side surface portions (8b) in the insert (5b). , 8b) and is constrained by three surfaces. In addition, the blade-tip-exchange-type rotary cutting tool equipped with the third insert (5b) can be used as a rotary tool used with a large number of cutting blades, for example, a tool such as a side cutter.

Since the insert (5b) according to the third embodiment has a set screw hole (11) for detachably attaching a screw from the outer peripheral surface side of the tool body, in designing the mounting seat of the tool body The work space for fixing the set screw and the avoidance of interference between the back metal part and the screw driver are not a concern, and maintenance such as re-installation of the insert or replacement of a new insert is easy. It also has a feature that it can be designed without worrying about the thickness of the back metal.
On the other hand, in the case of the insert according to the first embodiment described above, since the set screw of the insert is attached from the upper and lower surfaces of the insert, the work space is reduced. In addition, consideration must be given to avoiding interference between the back metal portion and the screw driver, and the number of inserts that can be mounted is limited depending on the tool diameter. Also, it takes time to install the insert.

(Fourth Embodiment of Insert)
Next, the configuration of the fourth embodiment of the longitudinal feed insert for forward and backward processing according to the present invention will be described with reference to FIG. The insert (5c) according to the fourth embodiment is a three-corner type insert. It is a front view of the upper surface portion (6), has a substantially triangular shape (substantially triangular shape), and is provided with corner portions (12a, 12b, 12c) at three corner portions of the substantially triangular shape, and each of the three corner portions. Corner blades (13a, 13b, 13c) are formed on (12a, 12b, 12c). Moreover, like the insert (5) which becomes above-mentioned 1st Embodiment, the main cutting blade (15a, 15b, 15c) is provided in one edge part of the corner blade (13a, 13b, 13c), Second sub-cutting blades (16a, 16b, 16c) are provided at the other end of the corner blades (13a, 13b, 13c). Furthermore, the first sub cutting edges (19a, 19b, 19c) for return path machining are formed in the direction of the set screw hole (11) from the end portions (t3) of the main cutting edges (15a, 15b, 15c), respectively. . Note that the second auxiliary cutting edges (16a, 16b, 16c) shown in FIG. 17 are not necessarily provided.

  In the insert (5c) according to the fourth embodiment, the corner blades (13a, 13b, 13c), the main cutting edges (15a, 15b, 15c), the first sub cutting edges (19a, 19b, 19c), the first As shown in FIG. 17, the rake surfaces (14a, 14b, 14c), which are the common rake surfaces of the two sub-cutting edges (16a, 16b, 16c), are connected to the corner portions (12a, 12b, 12c). Are formed so as to form an inclined surface inclined toward the set screw hole (11). Further, stepped wall surfaces (17a, 17b, 17c) are provided in order to compensate for the step between the rake face and the planar upper surface portion (18) of the upper surface portion 6. And like the above-mentioned insert (5), (5a), (5b), the flank (20a, 20b, 20c) is provided in the 1st sub cutting edge (19a, 19b, 19c), respectively.

  Since the insert (5c) having the above-described configuration is a three-corner type insert, for example, a corner blade (a cutting edge formed on a corner portion (12a) of the insert (5c) attached to the tool body (2) ( 13a), when the main cutting edge (15a), the second sub cutting edge (16a), and the first sub cutting edge (19a) are worn, the insert is reattached to the insert mounting seat (3) and the corner portion (12b The corner cutting edge (13b), the main cutting edge (15b), the second auxiliary cutting edge (16b), and the first auxiliary cutting edge (19b), which are the above-described cutting edges, are formed on the cutting edge. When the cutting edge according to the corner portion (12b) is worn, the insert is reattached to the insert mounting seat (3), and the cutting edge according to the corner portion (12c) is used for cutting.

  Thus, in the blade-tip-exchange-type rotary cutting tool of the present invention equipped with the three-corner type insert (5c), the life of the insert (5c) can be improved. In order to firmly attach the above-mentioned three-corner type insert (5c) to the insert mounting seat (3) of the tool body (2), the side surface portion facing the corner portion used for cutting and the vicinity thereof are arranged. A restraint wall surface for restraining is formed on the insert mounting seat (3).

By the cutting edge exchange type rotary cutting tool in which the inserts of the second to fourth embodiments of the insert according to the present invention described above are mounted, the work material is moved in the forward path and the return path by the movement path shown in FIG. The action at the time of cutting is the same as that of the blade-tip-exchange-type rotary cutting tool (1) equipped with the insert (5) according to the first embodiment.
Moreover, about embodiment of the above-mentioned insert which concerns on this invention, it was a 2 corner type insert provided with two corner parts which make a substantially parallelogram shape in front view, and was a double-sided type, and was provided with a total of four corner parts. The four-corner type insert and the three-corner type insert having a substantially triangular shape in front view and having three corner parts have been described. Can be applied.
The insert according to the present invention thus includes at least two arc-shaped corner portions, provided with corner blades at the corner portions, and the main cutting edge and the second auxiliary cutting edge described above on the respective corner portions (corner blades) side. , And a first sub-cutting edge for return path machining. Note that the second sub-cutting edge is provided according to the necessity for the purpose of cutting and the like.

  Further, the material of the base body of the insert according to the present invention is composed of high-speed steel, titanium carbide, silicon carbide, silicon nitride, aluminum nitride, aluminum oxide, and a mixture thereof in addition to the above-mentioned cemented carbide and cermet. An ultra-high pressure fired body that fires a hard phase composed of ceramics, cubic boron nitride sintered body, diamond sintered body, polycrystalline diamond or cubic boron nitride and a binder phase such as ceramics or iron group metal under ultra high pressure. It is also possible to use.

1: Cutting edge exchangeable rotary cutting tool 2: Tool body 3: Insert mounting seat 4: Clamp screw (set screw)
5, 5a, 5b, 5c: Insert 6: Upper surface portion 7: Lower surface portion 8a, 8b: Side surface portion 9a, 9b: Long edge ridge line portion 10a, 10b: Short edge ridge line portion 11: Set screw hole 12a , 12b, 12c: Corner portions 12c, 12d: Corner portions 13a, 13b, 13c: Corner blades 14a, 14b, 14c: Rake face of the main cutting edge 14a1, 14b1: On the central portion of the upper face portion of the rake face of the main cutting edge Ends 15a, 15b, 15c: Main cutting edges 16a, 16b, 16c: Second auxiliary cutting edges 17a, 17b, 17c: Stepped wall surfaces 18: Planar upper surface:
19a, 19b, 19c: 1st sub cutting edge 20a, 20b, 20c for return path processing: Flank of 1st sub cutting edge L: Length of 1st sub cutting edge M: Work material m1: Work material ( M) Standing wall m2: Bottom surface of the work material (M) m3: Finishing wall surface of the work material (M) O: Rotating axis of the blade cutting type rotary cutting tool P0: Center line of set screw hole P1: Insert 5 The center line P0 of the set screw hole passes through the center line P0 in the longitudinal direction of the insert P2: a straight line P3 passing through the center line P0 of the set screw hole in the plan view of the insert 5 and perpendicular to the straight line P1. : A straight line along the first sub cutting edge in a plan view of the insert 5 P4: A straight line orthogonal to the straight line P1 in a plan view of the insert 5 P5: An end t3 of the first sub cutting edge in a side view of the insert 5 Straight line extending along the flank from the bottom P6: A straight line orthogonal to the part 7 P7: a straight line along the main cutting edge in a side view of the insert 5 P8: a straight line orthogonal to the rotation axis O in a plan view of the cutting edge exchange rotary cutting tool P9: a cutting edge exchange rotary cutting A straight line along the first sub cutting edge in a plan view of the tool P10: a straight line along the flank face of the first sub cutting edge in a side view of the cutting edge exchange type rotating cutting tool P11: a side face of the cutting edge exchange type rotary cutting tool A straight line along the main cutting edge when viewed t1: One end of the corner blade (connecting portion with the main cutting edge)
t2: The other end of the corner blade (connecting portion with the second sub-cutting blade)
t3: The other end of the main cutting edge (the connecting portion with the first sub cutting edge)
t4: One end of the second sub-cutting edge t5: End of the ridge line portion of the short side of the rake face of the main cutting edge t6: The other end of the first sub-cutting edge Inclination angle in the longitudinal direction of the insert of the cutting edge θ2: Inclination angle in the thickness direction of the insert of the first sub-cutting edge for return path machining θ3: Inclination angle of the main cutting edge with respect to the lower surface portion of the rake face κ: First angle for inward machining 1 Cutting angle of the secondary cutting edge α: Clearance angle of the 1st secondary cutting edge for return path machining γ: Rake angle in the axial direction of the primary cutting edge

Claims (7)

  A polygonal flat plate shape, an upper surface portion, a lower surface portion that is formed at a position facing the upper surface portion and serves as a seating surface, a side surface portion that connects the upper surface portion and the lower surface portion, and a cutting edge for cutting work The insert is provided with a set screw hole, and at least two corners of the corners formed on the ridge line portion between the upper surface portion and the side surface portion are arc-shaped corner portions and corner blades are provided at the corner portions. In the state where the insert is mounted on the tool body, the insert is a cutting edge disposed on the outer peripheral side of the tool body, and is connected to the outer peripheral end (t1) of the corner blade. It has a length L along the edge of the rake face of the main cutting edge from the cutting edge and the other end (t3) on the outer peripheral side of the main cutting edge toward the center of the upper surface. Equipped with a first secondary cutting edge for return path machining The rake face of the main cutting edge is formed as a rake face that doubles as the rake face of the corner edge and the cutting edge for return path machining, and the rake face of the main cutting edge is against the lower surface portion. The height formed is formed to be higher than the central portion of the upper surface portion or the vicinity of the central portion, and the first auxiliary cutting edge for return path machining is directed from the rake face of the main cutting edge to the upper surface portion. Longitudinal feed insert for forward and return machining, characterized by having a flank surface formed so as to be lowered.   A ridge line portion formed by the rake face and the side surface portion of the main cutting edge, and further comprising a second sub cutting edge for outward machining connected to the other end (t2) of the corner blade. The longitudinal feed insert for forward and backward processing according to claim 1.   The upper surface portion includes at least two rake surfaces of the main cutting edge and a planar upper surface portion, and the rake surface of the main cutting edge includes an inclined surface that is inclined from the corner portion toward the planar upper surface portion. The longitudinal feed insert for forward path and backward path processing according to claim 1 or 2, wherein The rake face of the main cutting edge is configured to be connected to the planar upper surface via a stepped wall surface,
The longitudinal feed insert for the forward path and the backward path processing according to any one of claims 1 to 3, wherein a relief surface of the first sub cutting edge for the backward path machining is connected to the stepped wall surface. .   The insert has a substantially parallelogram shape with a pair of opposing ridge line portions as long sides and a pair of opposing ridge line portions as short sides among ridge line portions formed by the upper surface portion and the side surface portion in a top view. The longitudinal feed insert for forward path and backward path processing according to any one of claims 1 to 4, wherein the main cutting edge is provided on the ridge line portion of the long side.   The set screw hole is formed as a through hole penetrating from a planar upper surface portion of the upper surface portion to the lower surface portion, or as a through hole penetrating between a pair of side surface portions opposed to the center of the upper surface portion. The longitudinal feed insert for forward and backward processing according to any one of claims 1 to 5, wherein   A rotary cutting tool with replaceable cutting edges, wherein the longitudinal feed insert for forward and backward machining according to any one of claims 1 to 6 is detachably mounted on an insert mounting seat of a tool body, wherein the insert is The cutting edge exchange type rotary cutting tool, wherein the main cutting edge provided at the ridge line portion of the long side is arranged on the outer peripheral side of the tool main body in a state of being mounted on the tool main body.

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