JP6436093B2 - Cutting insert and cutting edge exchangeable cutting tool - Google Patents

Description

  The present invention relates to a cutting insert and a blade-tip-exchangeable cutting tool that is detachably mounted thereon. More specifically, the present invention relates to a cutting insert for right-angle shoulder cutting in which cutting edges are formed on the upper and lower surfaces, and a cutting edge-exchangeable cutting tool for detachably mounting the cutting insert.

  Conventionally, in the field of metal cutting, cutting of a processing side wall surface of a work material at a right angle to a processing bottom wall surface (ie, right-angle shoulder cutting) has been performed using a cutting edge-replaceable cutting tool. ing. An example of a cutting insert used for such right-angle shoulder machining is disclosed in Patent Document 1.

  In the cutting insert of patent document 1, the cutting edge is formed in the intersection ridgeline part of an upper surface and a side surface, and the intersection ridgeline part of a lower surface and a side surface, respectively. That is, the cutting insert of patent document 1 is a double-sided use type which can be used for cutting by changing the upper and lower sides. The cutting insert of patent document 1 is also what is called a negative type cutting insert similarly to the cutting insert which can be used on both sides. Therefore, the side surfaces extend with a clearance angle of 0 ° with respect to the upper surface and the lower surface. The cutting edge is a connecting part between the main cutting edge for cutting the processing side wall surface of the work material, the wiping edge for cutting the processing bottom wall surface of the work material, and the processing side wall surface and the processing bottom wall surface. And a corner blade between them for cutting corners.

  And the cutting insert of patent document 1 has a substantially equilateral triangle shape in planar view, and has three cutting edges in each of an upper surface or a lower surface. Therefore, it has six cutting edges in combination with the upper surface and the lower surface. Therefore, this cutting insert is economical because the cutting edge can be used six times on the upper surface and the lower surface.

International Publication No. 2013/153547

  Currently, in the market, from the viewpoint of economy, it is required to smooth the processed surface of a work material at a high level in one cutting. That is, it is not necessary to perform further finishing, and it is required to process the processed surface more smoothly to a finished state by a single cutting. Even with the cutting insert of Patent Document 1, the processing bottom wall surface of the work material may be finished to a certain degree of smoothness with a wiping blade. However, there is a demand for further smoothing.

  This invention is made | formed in view of the said subject, and aims at providing the cutting insert which can improve the smoothness of a processed surface.

According to one aspect of the invention,
In a cutting insert having a first end surface, a second end surface disposed to face the first end surface, and a peripheral side surface extending between the first end surface and the second end surface,
At least one cutting edge section is formed in the intersecting ridge line portion between the first end surface and the peripheral side surface,
The cutting edge section includes a main cutting edge, a wiping edge, and a corner blade that connects the main cutting edge and the wiping edge,
In a plan view on the first end face side of the cutting insert, the corner blade extends to a corner portion of the first end face,
When a surface extending between the first end surface and the second end surface of the cutting insert is defined as an intermediate surface, the main cutting edge is inclined so as to approach the intermediate surface as the distance from the corner blade increases.
In a side view of the cutting insert, at least a part of the wiping blade has a concavely curved shape on the intermediate surface side.
A cutting insert is provided.

  According to one aspect of the present invention having the above-described configuration, at least a part of the wiping blade has a shape that is concavely curved toward the intermediate surface in a side view of the cutting insert. Therefore, when the cutting insert is attached to the tool body, the radius of curvature of the predetermined section in the trajectory of the wiping blade can be made larger than that of the conventional one. Therefore, it is possible to significantly improve the smoothness of the processed surface by the wiping blade.

  A part of the peripheral side surface of the cutting insert may be configured to function as a flank for the cutting edge section. In this case, the first end face may be configured to function as a rake face for the cutting edge section. The cutting insert can be formed to be a negative type having a clearance angle of 0 °.

  Here, a first axis extending so as to penetrate the first end surface and the second end surface is defined, and a second axis penetrating the peripheral side surface perpendicular to the first axis is defined. The second axis is included in the intermediate surface. The number of cutting edge sections formed at the intersection ridge line portion between the first end face and the peripheral side face may be n (where n is an integer of 2 or more). In this case, the plurality of cutting edge sections may be arranged so as to be rotationally symmetric about n times around the first axis. Further, a plurality of cutting edge sections are also formed on the intersecting ridge line portion between the second end surface and the peripheral side surface so as to be 180 ° rotationally symmetric around the second axis with respect to the plurality of cutting edge sections on the first end surface side. Can. Preferably, in the plan view of the cutting insert, the outline of the first end surface is formed by alternately and continuously arranging the corner portion and a substantially linear side portion from which the main cutting edge extends. ing.

  Preferably, in a plan view of the cutting insert, at least a part of the wiping blade and the corner blade are provided at a corner portion of the first end surface. More preferably, the entire wiping blade is provided in the corner portion. Preferably, in a plan view of the cutting insert, the corner portion is formed symmetrically with respect to the bisector of the corner portion, and in a single cutting edge section, the main cutting edge is the two cutting edges. It extends to one side of the bisector, and at least half of the wiping blade extends to the other side of the bisector. More preferably, the entire wiping blade extends to the other side of the bisector.

  The wiping blade may be formed so as to gradually approach the intermediate surface as it moves away from the corner blade. In this case, more preferably, the wiping blade has an angle of inclination with respect to the intermediate surface on the corner blade side in the side view of the cutting insert from a position along the bisector of the corner portion in plan view of the cutting insert. It is good to form so that it may be larger than the inclination angle with respect to the intermediate surface on the corner blade side. The corner blade may gradually approach the intermediate surface as it moves away from the main cutting edge.

  In one embodiment, the outline shape of the cutting insert is a substantially equilateral triangle in the plan view of the cutting insert. Preferably, the cutting insert is for right-angle shoulder cutting.

  The present invention also resides in a cutting tool. According to another aspect of the present invention, there is provided a cutting edge-exchangeable cutting tool including a tool body having at least one insert mounting seat, and having a cutting insert detachably attached to the insert mounting seat. The cutting insert used in this cutting tool may be any of the cutting inserts described above.

FIG. 1 shows a perspective view of a cutting insert according to an embodiment of the present invention. FIG. 2 shows a plan view of the cutting insert of FIG. 3 shows a side view of the cutting insert of FIG. 1 when viewed from the X direction of FIG. 4 shows a side view of the cutting insert of FIG. 1 when viewed from the Y direction of FIG. FIG. 5 shows an enlarged view of the vicinity of one corner portion in the plan view of FIG. FIG. 6 shows an enlarged view of the vicinity of the corner portion in the side view of FIG. FIG. 7 shows a perspective view of a blade-tip-exchangeable cutting tool according to an embodiment of the present invention. FIG. 8A is a plan view of the tip side portion of the tool body in the cutting edge exchangeable cutting tool of FIG. FIG. 8B shows an end view of the tip side of the tool body in the cutting edge exchangeable cutting tool of FIG. FIG. 9 shows an enlarged view of the vicinity of the cutting insert of the cutting edge exchangeable cutting tool shown in FIG. FIG. 10 schematically shows a usage mode of the cutting edge exchangeable cutting tool of FIG. FIG. 11 is a view of a portion of the wiping blade surrounded by a circle XI in FIG. 10, and shows a conceptual diagram comparing the wiping blade in the conventional cutting tool and the wiping blade in the cutting tool in FIG. 7.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  The cutting insert 1 which concerns on one Embodiment of this invention has the two end surfaces 2 and 3 which oppose, and the surrounding side surface 4 which connects them as FIG. 1-4 shows. In the following, one end face 2 (corresponding to the first end face of the present invention) 2 facing upward in FIG. 3 is referred to as an upper face, and the other end face (corresponding to the second end face of the present invention) 3 is referred to as a lower face. Based on the relative positional relationship between the upper surface 2 and the lower surface 3, the terms “upper” and “lower” can be used in the following description. However, these terms do not limit the orientation or position of the cutting insert 1, but are merely used to facilitate understanding thereof, and are not intended to limit the present invention.

  The cutting insert 1 has a mounting hole 5 that is a through hole so as to penetrate the upper surface 2 and the lower surface 3. Therefore, a substantially circular opening of the attachment hole 5 is formed in the substantially central portion of each of the upper surface 2 and the lower surface 3.

  As can be understood from FIG. 2, when the cutting insert 1 is viewed in a plan view (particularly FIG. 2 is a top view) of the cutting insert 1, that is, when viewed from the side facing the upper surface 2, the upper surface 2 of the cutting insert 1 is It has a substantially triangular outer shape. In FIG. 2, the contour of the upper surface 2 is composed of three side parts 6 and three corner parts 7 arranged substantially continuously between the side parts 6. In FIG. 2, the side part 6 has a substantially linear shape, and the corner part 7 has a curved shape as a whole. The three side portions 6 have the same length, and the three corner portions 7 also have the same length and shape. In the present embodiment, the angle formed by the extension lines of the two adjacent side portions 6 in FIG. 2 is approximately 60 °. Therefore, the cutting insert 1 of this embodiment has a substantially equilateral triangular outer shape in a plan view of FIG. The lower surface 3 has the same shape as the upper surface 2 in a plan view (that is, a bottom view) (not shown). Here, an axis passing through a substantially center point of the upper surface 2 and a substantially center point of the lower surface 3 in plan view is defined as a center axis A1. Here, the central axis A1 coincides with the central axis of the mounting hole 5 and corresponds to the first axis of the present invention. In addition, since the cutting insert 1 has a substantially triangular outline in plan view, it is formed so as to be rotationally symmetric about the central axis A1 three times.

  Three cutting edge sections (that is, cutting edges) 15 are formed at the intersecting ridge line portion between the upper surface 2 and the peripheral side surface 4. Each cutting edge section 15 has a corresponding one corner portion 7 and a corresponding one side portion 6. The cutting edge section 15 includes three cutting edges (ie, cutting edge portions) 8, 9, and 10. More specifically, each cutting edge section 15 includes a main cutting edge 8, a corner edge 9, and a wiping edge 10. The main cutting edge 8 is formed along the straight side portion 6. The corner blade 9 is formed along a part of the corner portion 7. The wiping blade 10 is formed along the other part of the corner portion 7. When the cutting insert 1 is attached to the tool body 21 (described later) so as to use one cutting edge section 15 on the upper surface 2 side, a part of the upper surface 2 can function as a rake face, and the peripheral side surface 4 A part of can function as a flank. At the same time, the lower surface 3 can function as a seating surface that contacts the bottom wall surface 23 of the insert mounting seat 22 of the tool body 21.

  On the other hand, in the cutting insert 1 of the present embodiment, three cutting edge sections 15 having cutting edges 8, 9, and 10 are formed in the intersection ridge line portion between the lower surface 3 and the peripheral side surface 4 as well as the upper surface 2 side. Has been. Here, the second axis A2 (see FIGS. 3 and 4) is determined so as to be orthogonal to the central axis A1 and pass through the peripheral side surface 4. The cutting edge section 15 on the lower surface 3 is formed so as to be 180 ° rotationally symmetric about the second axis A2 with respect to the cutting edge section 15 on the upper surface 2. Therefore, the arrangement of the cutting edges 8, 9, 10 formed on the upper surface 2 in a top view (plan view), and the arrangement 8, 9, 10 of the cutting edges formed on the lower surface 3 in a bottom view; Are the same. In FIG. 2 to FIG. 4, only one line is shown as the second axis, but in the cutting insert 1, each of the three lines can be used as the second axis, one of which is the second axis. Note that it is represented as axis A2.

  When the cutting insert 1 is attached to the tool body 21 so as to use one cutting edge section 15 on the lower surface 3 side, a part of the lower surface 3 can function as a rake face and a part of the peripheral side surface 4 escapes. Can function as a surface. At the same time, the upper surface 2 can function as a seating surface that abuts against the bottom wall surface 23 of the insert mounting seat 22 of the tool body 21.

  Thus, since the cutting edge is formed in both the upper surface 2 and the lower surface 3, the cutting insert 1 of this embodiment is what is called a negative type. With respect to the upper surface 2 or the lower surface 3, the peripheral side surface 4 extends so that the clearance angle is 0 ° over the entire outer shape of the upper surface 2 and the lower surface 3. Therefore, when a surface (not shown) is defined so as to be perpendicular to the axis A1 and pass through the cutting edge, the peripheral side surface 4 extends so as to be perpendicular to the surface.

  As described above, the shape when the cutting insert 1 is viewed from the direction facing the upper surface 2 is the same as the shape when the cutting insert 1 is viewed from the direction facing the lower surface 3. Therefore, although the structure of the cutting insert 1 of this embodiment is demonstrated centering on the upper surface 2 from this, the structure is the same also in the lower surface 3. FIG.

  The linear main cutting edge 8 is configured to be able to participate in the cutting of the side wall surface of the workpiece. In the cutting insert 1 of this embodiment, the main cutting edge 8 is formed over the entire one side portion 6. In the cutting insert 1, the main cutting edge 8 may have a convex curved shape that slightly bulges outward as a whole in a plan view of the cutting insert 1.

  In FIG. 2, the curved corner portion 7 has a corner blade 9 that can be involved in the cutting of the corner where the side wall surface and the bottom wall surface of the workpiece intersect, and the cutting of the bottom wall surface of the workpiece. The wiping blades 10 that can be formed are formed side by side. The cutting edges 8, 9, 10 are continuous in the order of the main cutting edge 8, the corner edge 9, and the wiping edge 10, which can participate in cutting as one set (that is, one cutting edge section 15).

  Here, the corner portion 7 will be described in more detail with reference to a plan view. FIG. 5 shows an enlarged view of the vicinity of the corner portion 7 in the plan view or the top view of FIG. As shown in FIG. 5, the corner portion 7 is formed symmetrically with respect to the bisector C of the apex angle of the corner portion 7. Here, although not shown in FIG. 5, the bisector C passes through the axis A1. Note that the bisector C can overlap the second axis A2 in a plan view of the cutting insert.

  The position where the bisector C crosses the cutting edge in FIG. 5 can be defined as the tip center point B of the corner portion 7. Therefore, the bisector C connects the axis A1 and the tip center point B. Further, a curved corner blade 9 is arranged on one end side of the corner portion 7 to which the main cutting edge 8 forming a pair in one cutting edge section 15 is connected, and a curved line adjacent to the corner blade 9 is curved. A shaped wiping blade 10 is formed. The wiping edge 10 of one cutting edge section 15 is not continuous to the main cutting edge 8 of another adjacent cutting edge section 15. Therefore, in the corner portion 7, the connecting portion 11 exists between the wiping blade 10 and the main cutting edge 8 of the adjacent cutting edge section 15. The connecting portion 11 is a non-cutting portion that does not participate in cutting in the right shoulder machining. However, the connecting portion 11 can be a cutting edge involved in cutting in the ramping process and can be included in the cutting edge section 15. Therefore, in the drawing, the connecting portion 11 is included in the cutting edge section 15, but the connecting portion 11 may not be included in the cutting edge section 15. Thus, it should be noted that the connection portion (connection edge portion) 11 may function as a cutting edge or may not participate in cutting at all depending on the applied processing. It is.

  In FIG. 5, the bisector C passes through the boundary portion between the corner blade 9 and the wiping blade 10 in the same corner portion 7. Therefore, in FIG. 5, in the single cutting edge section 15, the main cutting edge 8 is arranged on one side of the bisector C, and the wiping edge 10 is arranged on the other side of the bisector C. Thus, in the cutting insert 1 of the present embodiment, the entire corner blade 9 extends on one side of the bisector C in the plan view, and the wiper blade 10 on the other side of the bisector C. The whole is extended. Thus, in a single cutting edge section 15, the main cutting edge 8 extends on one side of the bisector C and the wiping edge 10 extends on the other side of the bisector C.

  However, the present invention does not exclude a change in which at least half of the corner blade 9 is located on one side of the bisector C (that is, the rest of the corner blade is located on the other side of the line C). Further, the present invention does not exclude a change in which at least half of the wiping blade is located on the other side of the bisector C (that is, the rest of the wiping blade is located on one side of the line C). About the ratio of the length between the corner blade 9, the wiping blade 10, and the connection portion 11 in the same corner portion 7, it is possible to appropriately change according to the required shape of the corner portion 7, Note that the configuration is not limited to that described in FIG. Moreover, the corner part 7 should just have a substantially curved shape as a whole in planar view, The one part may be comprised from the linear shape, and the corner part 7 has a continuous short linear shape. Therefore, a configuration having an approximately curved shape may be used.

  Here, as shown in FIGS. 3 and 4, a surface perpendicular to the axis A <b> 1 and extending between the upper surface 2 and the lower surface 3 of the cutting insert 1 is defined as an intermediate surface M. In particular, the intermediate surface M is defined here so as to substantially pass through a central position between the upper surface 2 and the lower surface 3, and includes the second axis A2. When the cutting insert 1 of the present embodiment is viewed from the front (side view), that is, cut from a direction perpendicular to the axis A1 (position along the second axis A2) as shown in FIG. 3 or FIG. When the insert 1 is viewed, the intermediate surface M is represented as a straight line perpendicular to the axis A1. This straight line or intermediate surface M is used in the following description as a reference line or reference surface.

  FIG. 3 is a view taken in the direction of arrow X in FIG. 2 and shows a side view of the cutting insert 1 when the cutting insert 1 is viewed from the X direction in FIG. 4 is a view as seen from the direction of the arrow Y in FIG. 2, and shows a side view of the cutting insert 1 when the cutting insert 1 is viewed from the Y direction in FIG. That is, FIG. 4 is a view when the cutting insert 1 is viewed from a position along the bisector C (see FIG. 5) of the corner portion 7. 6 shows an enlarged view of the vicinity of one corner portion 7 on the upper surface 2 side in FIG. In FIG. 2, the X arrow and the Y arrow overlap the second axis A <b> 2, the X arrow points to one side portion 6, and the Y arrow points to one corner portion 7.

  3 and 4, the side portion 6 is linear. In FIG. 4, the corner portion 7 is curved in a substantially S shape.

  In these side views of the cutting insert 1, a virtual contour for one cutting edge section 15 can be defined. The virtual contour line is defined as a smooth curve in a region extending from the main cutting edge 8 to the wiping edge 10, and is particularly determined to have one apex. In FIG. 6, only the imaginary line portion IL extending away from the cutting edge section 15 among the imaginary contour lines is indicated by a broken line.

  Regarding the distance between each of the cutting edges 8, 9, 10 of the cutting edge section 15 and the intermediate surface M, the length between the intermediate surface M at the connecting portion 8a between the main cutting edge 8 and the corner blade 9 is the maximum. It is. However, the distance between the cutting edge section 15 and the intermediate surface M is the length between the intermediate surface M in the direction parallel to the axis A1 at each value of the cutting edge section 15. Here, the connecting portion between the main cutting edge 8 and the corner blade 9 is determined along the main cutting edge 8 because the main cutting edge 8 is formed in a straight line in both a plan view and a side view. This corresponds to a portion (point) starting to deviate from the virtual straight line 8L (see FIG. 6).

  As the distance from the corner blade 9 increases along the main cutting edge 8, the length between the main cutting edge 8 and the intermediate surface M gradually decreases. On the other hand, the distance between the corner blade 9 and the intermediate surface M is gradually shortened from the connecting portion between the main cutting edge 8 and the corner blade 9 toward the sweeping blade 10 side. Further, the distance between the wiping blade 10 and the intermediate surface M is gradually shortened as the distance from the corner blade 9 increases. Furthermore, the distance between the connecting portion 11 and the intermediate surface M is also gradually reduced as the distance from the sweeper blade 10 increases. And in the part 11a slightly located in the main cutting edge 8 side from the connection part of the connection part 11 of the said cutting edge section 15, and the main cutting edge 8 of the adjacent cutting edge section 15, the cutting edge section 15 and an intermediate surface The distance to M is the shortest. That is, the closest portion 11 a to the intermediate surface M of the cutting edge section 15 is located at the connection portion 11.

  As described above, in the cutting insert 1 of the present embodiment, the main cutting edge 8 has the connecting portion 11 of the corner portion 7 of the adjacent cutting edge section 15 from the corner blade 9 side of the corner portion 7 belonging to the same cutting edge section 15. A constant inclination is provided so that the distance from the intermediate surface M gradually decreases toward the center. The main cutting edge 8 of the present embodiment is linear in a side view, but is not limited to this and may be curved. On the other hand, the corner portion 7 (particularly the corner blade and the countersink blade) is intermediate from the connecting portion 8a between the main cutting edge 8 and the corner blade 9 in the related cutting edge section 15 toward the connecting portion 11 of the cutting edge section 15. The distance from the surface M is configured to gradually become shorter (that is, closer to the intermediate surface M). However, unlike the main cutting edge 8, the corner portion 7 is composed of a plurality of parts (corner blade 9, sweeper blade 10, connection portion 11), and is not configured to be inclined at a constant inclination.

  Further, the shapes of the corner blade 9 and the wiping blade 10 in a side view will be described in more detail with reference to FIG. As described above, the length between the cutting edge section 15 and the intermediate surface M is the largest in the connecting portion 8a between the main cutting edge 8 and the corner edge 9, and the wiping edge 10 adjacent to the corner edge 9 is present. As it goes to the side, its length gradually decreases. Specifically, the corner blade 9 is curved so as to protrude upward (that is, outward) in a side view. Therefore, the corner blade 9 is formed so that the inclination angle with respect to the intermediate surface M increases as the distance from the main cutting edge 8 and the closer to the wiping edge 10 side in FIG.

  As described above, the wiping blade 10 is basically inclined so that the distance from the intermediate surface M gradually decreases as the distance from the adjacent corner blade 9 increases. However, the wiping blade 10 is formed so that the inclination changes differently from the corner blade 9. Specifically, the wiping blade 10 is formed such that the angle of inclination with respect to the intermediate surface M gradually increases as the corner blade 9 moves away from the corner blade 9 side. On the other hand, on the connecting portion 11 side (anti-corner blade side), the wiping blade 10 is formed so that the inclination angle with respect to the intermediate surface M gradually decreases as the distance from the corner blade 9 increases. Therefore, as shown in FIG. 6, the wiping blade 10 is concavely curved toward the intermediate surface side so that the inclination angle α with respect to the intermediate surface on the corner blade side is larger than the inclination angle β with respect to the intermediate surface on the anti-corner blade side. . However, the inclination angle α with respect to the intermediate surface on the corner blade side of the wiping blade 10 is larger than the inclination angle with respect to the intermediate surface of the corner blade 9. That is, as apparent from FIG. 6, the wiping blade 10 has a substantially arcuate shape in which the overall shape is curved toward the lower surface 3 side, that is, toward the intermediate surface M side in a side view. Therefore, when the virtual contour line is defined with respect to the cutting edge section 15 as described above, the virtual line portion IL in FIG. 6 is drawn only with respect to the wiping edge 10 of the cutting edge section 15. Thus, in this embodiment, the wiping blade 10 is an imaginary line that is defined so as to connect the start point portion (connection portion with the adjacent corner blade 9) and the end point portion (connection portion with the adjacent connection portion 11). It is formed so as to be concavely curved toward the intermediate surface M side than the portion IL. The imaginary line portion IL is determined substantially following the curved shape of the corner blade 9. As described above, the portion extending from the corner blade 9 to the wiping blade 10 is shaped in a side view, and thus is curved into a substantially S shape (see FIG. 6).

  In the present embodiment, the entire wiping blade 10 has a curved shape that is curved toward the intermediate surface M in side view (that is, extends below the imaginary line portion IL). However, the shape of the wiping blade need not be limited to that shape, and only a portion of the wiping blade may have a curved shape curved toward the intermediate surface M side. In that case, the planar blade 10 may occupy a wider area in the corner portion 7 in plan view. That is, the present invention allows a configuration in which the wiping blade 10 extends to the corner blade 9 side or the connection portion 11 side.

  Furthermore, an identification mark (not shown) of the used corner may be provided on the upper surface 2 and / or the lower surface 3 on the surface near the corner portion 7. When the identification mark is provided for each corner portion, the pattern may be different for each corner portion 7. Thereby, the order of using the corner portions 7 on the upper surface 2 or the lower surface 3 is known, and it is possible to prevent the operator from using the cutting edge once used by mistake again. Further, the cutting insert 1 has a rake face-corresponding portion shaped so as to give a positive rake angle. However, the angle (rake angle) and shape of the upper surface 2 or the lower surface 3 that can function as a rake face can be appropriately changed according to cutting conditions, the type of work material, and the like. Further, the upper surface 2 or the lower surface 3 can be provided with irregularities such as a chip breaker as necessary.

  The cutting insert 1 can be made from a hard material such as cemented carbide, coated cemented carbide, cermet, ceramic, or an ultra-high pressure sintered body containing diamond or cubic boron nitride.

  Next, a description will be given of a cutting edge-exchangeable cutting tool 20 provided with a tool body 21 to which the cutting insert 1 is detachably attached with reference to the drawings. FIG. 7 shows a cutting edge-replaceable cutting tool 20 according to this embodiment in which the cutting insert 1 is mounted on the tool body 21. The tip of the tool body 21 is shown in FIGS. 8A and 8B. FIG. 9 shows an enlarged view of the tip of the cutting edge-exchangeable cutting tool 20, particularly in the vicinity of the cutting insert 1.

  The tool body 21 basically has a substantially cylindrical shape, and a rotation axis O extending from the front end portion toward the rear end portion can be defined. The rear end side of the tool body 21 is a part attached to the machine tool. Three insert mounting seats 22 are provided on the distal end side of the tool body 21. The cutting insert 1 can be detachably mounted on each of the three insert mounting seats 22. Thus, the blade-tip-exchangeable cutting tool 20 of this embodiment is a three-blade type to which the three cutting inserts 1 are attached. In the cutting edge replacement type cutting tool 20 of the present embodiment, the three insert mounting seats 22 are arranged at substantially equal intervals around the rotation axis O in the front end surface view of the tool body 21 (FIG. 8B). However, the three insert mounting seats 22 can also be arranged at uneven intervals around the axis O. Further, the number of the insert mounting seats 22 is not limited to three, and can be set to any other number. That is, the cutting edge exchange type cutting tool of the present invention is not limited to three blades. Moreover, although only one insert mounting seat 22 can be provided in the cutting edge exchange type cutting tool of the present invention, a plurality of insert mounting seats 22 are preferably provided.

  The insert mounting seat 22 has a bottom wall surface 23 and two side wall surfaces 24 a and 24 b that are substantially perpendicular to the bottom wall surface 23. The bottom wall surface 23 is formed to face the tool rotation direction K front. Here, the tool rotation direction means a direction in which the cutting tool 20 is rotated relative to the work material, and the cutting tool 20 may be rotated with respect to the work material. The workpiece may be rotated relative to the workpiece.

  A screw hole 25 for fixing the cutting insert 1 with screws as fixing means is provided in a substantially central portion of the bottom wall surface 23 of the insert mounting seat 22. In this embodiment, since the cutting insert 1 is substantially triangular, the shape of the bottom wall surface 23 of the insert mounting seat 22 is also substantially triangular, but other shapes are possible.

  The first side wall surface 24a of the insert mounting seat 22 is a surface facing the tool tip side and the tool outer peripheral side. The second side wall surface 24b of the insert mounting seat 22 is positioned closer to the tool front end side than the first side wall surface 24a and faces the tool rear end side and the tool outer peripheral side. The first side wall surface 24a and the second side wall surface 24b are combined to partially define a region in which a cutting edge on which the cutting insert 1 does not act is accommodated. Each of the first side wall surface 24a and the second side wall surface 24b is formed such that a side surface of the cutting insert 1 (a side surface extending along the non-working cutting edge section 15 of the peripheral side surface 4) can be preferably contacted. Yes.

  A chip pocket 26 for processing chips is provided adjacent to the insert mounting seat 22. Here, the chip pocket 26 is formed so as to cut out the tool body 21 approximately half a month toward the rear end side of the tool body 21. However, the shape and size of the chip pocket 26 are not limited to those shown in the drawings, and can be appropriately changed.

  In the cutting insert 1, the upper surface 2 or the lower surface 3 of the cutting insert 1 is in contact with the bottom wall surface 23 of the insert mounting seat 22, and a part of the peripheral side surface 4 of the cutting insert 1 is in contact with the side wall surfaces 24 a and 24 b of the insert mounting seat 22. It mounts on the insert mounting seat 22 so that it may contact | connect. Therefore, when the cutting insert 1 is disposed on the insert mounting seat 22, the rake face (the upper surface 2 or the lower surface 3) of the cutting insert 1 faces forward in the tool rotation direction K. In the state where the cutting insert 1 is arranged on the insert mounting seat 22 in this way, the screw 22 s is firmly screwed into the screw hole 25 of the insert mounting seat 22 of the tool body 21 through the mounting hole 5 of the cutting insert 1. Thereby, the cutting insert 1 can be fixed to the insert mounting seat 22. The bottom wall surface 23 and the side wall surfaces 24a and 24b of the insert mounting seat 22 are designed so that the cutting insert 1 having the above-described configuration is arranged with a predetermined radial rake and a predetermined axial rake.

  The cutting edge replacement type cutting tool 20 to which the cutting insert 1 is mounted in this way can be rotated around the rotation axis O and used for right-angle shoulder cutting. FIG. 10 schematically shows the cutting tool 20 in a state of shouldering at right angles to the work material W. At this time, as understood from FIG. 10, the main cutting edge 8 that is located on the outer peripheral side of the tool and extends generally in the direction of the tool rotation axis O, and is perpendicular to the tool rotation axis O located on the tool tip side. The wiping blade 10 extending generally on the flat surface and the corner blade 9 located on the tool outer peripheral side and the tool tip side serve as a working cutting edge (working cutting edge section). The working main cutting edge 8 is involved in the cutting of the side wall surface of the workpiece, the working wiping blade 10 is involved in the cutting of the bottom wall surface of the workpiece, and the working corner blade 9 is connected to the side wall surface and the bottom wall surface of the workpiece. Involved in the cutting of the corners between.

  In the cutting edge replacement type cutting tool 20 of this embodiment, when the cutting edge section 15 used by the cutting insert 1 is worn or the like, the cutting edge section 15 can be changed to another unused cutting edge section 15. it can. Since the cutting insert 1 can be used on both sides and can be indexed, the cutting insert 1 has six sets of cutting edge sections 15 on the upper surface 2 and the lower surface 3 and can be used six times. In the present invention, the shape of the cutting insert in plan view is not limited to a substantially triangular shape, and other polygonal shapes are possible. Therefore, a number of sets of cutting edges corresponding to the polygonal shape are used for cutting. Is possible.

  Next, the operation and effect of the cutting insert 1 of the present embodiment and the cutting edge-exchangeable cutting tool 20 equipped with the cutting insert 1 will be described.

  In the cutting insert 1 of the present embodiment, as described above, the wiping blade 10 has a curved shape curved toward the intermediate surface M side in a side view of the cutting insert 1. Thereby, in the present invention, the smoothness of the processed surface can be greatly improved. This is due to the following reason.

  A general wiping blade has an arc shape in plan view, and has a linear shape or a curved shape curved outward (for example, the shape described in Patent Document 1) in side view. In a conventional cutting tool equipped with a cutting insert having such a shape of the wiping blade, the outer shape CA of the wiping blade when the wiping blade is viewed from the direction perpendicular to the tool rotation center axis O is as follows: FIG. 11 schematically shows a broken line.

  On the other hand, the wiping blade 10 of the cutting insert 1 according to the embodiment of the present invention has an arc shape in a plan view, and has a curved shape (that is, a concave curve shape) curved toward the intermediate surface M in a side view. Have. FIG. 11 schematically shows the outline shape of the wiping blade 10 (enclosed by the circle XI in FIG. 10) in the cutting insert 1 as viewed from the direction perpendicular to the tool rotation center axis O in FIG. It is shown with a solid line. Here, in FIG. 11, it is assumed that the conventional cutting insert and the cutting insert 1 are mounted on the tool body so that the true clearance angle is the same.

  In FIG. 11, the cutting edge ridge line of the cutting edge 10 of the cutting insert 1 according to the embodiment of the present invention retreats by the maximum ΔD inward of the cutting insert as compared with the cutting edge ridge line CA of the conventional cutting edge. doing. As described above, this is because the wiping blade 10 is curved toward the intermediate surface M in a side view, that is, as the wiping blade 10 moves away from the corner blade 9 side, it escapes to the intermediate surface M side. This is because. Thus, the wiper blade 10 of the present invention has a larger radius of curvature in any cross-section (but including the axis O) of the wiper blade's rotational trajectory around the rotation axis O as compared to a conventional wiper blade (ie, more It will have a cutting edge profile (approaching a straight line). Therefore, the portion of the work material that remains uncut is reduced, so that the theoretical surface roughness can be greatly improved. That is, the smoothness of the processed surface can be greatly improved.

  Further, in the cutting insert 1 according to the embodiment of the present invention, the entire wiping blade 10 is inclined with respect to the intermediate surface M in a side view, and further, with respect to a virtual line IL connected to the corner blade 9. A concave curve is made so as to approach the intermediate surface M. However, the wiping blade may have a configuration other than the above. For example, the wiping blade may be designed such that an imaginary line IL for the wiping blade is defined substantially parallel to the intermediate surface M. However, in the case of the negative type cutting insert as in the present invention, since it is necessary to set the axial rake to be negative, a large cutting resistance is applied compared to the positive type, thereby causing chatter and smoothing of the machining surface. The degree may be further reduced. In contrast, by providing the wiping blade 10 with the inclination in the side view as described above, the wiping blade 10 can be gradually cut into the work material. Therefore, according to the cutting insert 1 and the cutting tool 20, it is possible to reduce the impact when the wiping blade is involved in the work material. As a result, since the occurrence of chatter can be suppressed, an effect of further improving the smoothness of the processed surface can be obtained. Thus, it is particularly effective in the negative type to provide the wiping blade 10 with an inclination. Of course, the above-described configuration of the wiping blade is effective in further reducing the cutting resistance even in the positive type.

  Further, it is not necessary for the entire wiping blade 10 to have a curved shape curved toward the intermediate surface M in a side view (that is, below the imaginary line IL), and only a part thereof is curved toward the intermediate surface M side. It may be a curved shape. Even in the case of this embodiment, the radius of curvature of the wiping blade is sufficiently larger than that of the conventional wiping blade, so that the above-described smoothness improving effect can be obtained. Further, the curved shape of the wiping blade can be appropriately changed in view of required smoothing performance and the like.

  Moreover, in the wiping blade 10, the smoothing performance of the wiping blade 10 can be improved only by changing the curved curved shape in the side view without changing the shape of the cutting insert 1 in the plan view. This is a great advantage. That is, in the negative insert of double-sided use like the cutting insert 1, the corner portion may be formed symmetrically with respect to the bisector C (for example, regarding the formation of a smooth corner shape on the work material). Since this is advantageous, there is a great design limitation on the shape of the wiping edge (curvature radius, etc.) in plan view. On the other hand, in the above embodiment of the present invention, as described above, the smoothing performance can be improved without changing the shape of the wiping blade 10 in plan view. .

  The cutting insert 1 of the present invention is not limited to those used for tools for turning, and can be applied to those used for other tools such as turning and drilling. .

  Although the present invention has been described with a certain degree of specificity in the above-described embodiments, the present invention is not limited to this. It should be understood that various changes and modifications can be made to the present invention without departing from the spirit and scope of the claimed invention. That is, the present invention includes all modifications, applications, and equivalents included in the concept of the present invention defined by the claims.

Claims (10)

It extends between the first end surface (2), the second end surface (3) disposed opposite to the first end surface (2), and between the first end surface (2) and the second end surface (3). A cutting insert (1) having an existing circumferential side (4),
A plurality of cutting edge sections (15) are formed in the intersecting ridge line portion between the first end surface (2) and the peripheral side surface (4),
The cutting edge section includes a main cutting edge (8), a wiping edge (10), and a corner cutting edge (9) connecting the main cutting edge and the wiping edge,
A connecting portion (11) is formed connecting the wiper blade (10) and the main cutting edge (8) of the adjacent cutting edge section;
In a plan view on the first end face side of the cutting insert, the corner blade (9) extends to a corner portion (7) of the first end face,
The central axis of the mounting hole penetrating the first end surface (2) and the second end surface (3) is defined as the first axis (A1) and is orthogonal to the first axis (A1), and When the surface extending between the first end surface (2) and the second end surface (3) is defined as an intermediate surface (M), the intermediate cutting edge (8) is separated from the corner cutting edge (9) as the intermediate cutting edge (8) becomes intermediate. Inclined so as to approach the surface
In the side view of the cutting insert (1), the connecting portion (11) has a concavely curved shape toward the intermediate surface (M), and the connection between the wiping blade (10) and the corner blade (9). When the imaginary line which connects a part and the connection part of the said wiping blade (10) and the said connection part (11) is defined, at least one part of the said wiping blade (10) was concave-curved rather than the said imaginary line Have a shape,
Cutting insert (1). A portion of the peripheral side of the cutting insert (1) is configured to function as a flank for the cutting edge section;
The cutting insert according to claim 1, wherein the peripheral side surface is parallel to the first axis (A1). The intermediate surface (M) passes through a central position between the first end surface (2) and the second end surface (3),
When defined as a line extending on said intermediate face perpendicular to said first axis (A1) (M) second axis (A2, A3),
The number of the cutting edge sections (15) formed in the intersecting ridge line portion between the first end surface (2) and the peripheral side surface (4) is n (where n is an integer of 2 or more), The cutting edge section is arranged to be rotationally symmetric about n times about the first axis,
A plurality of cutting edge sections are also formed on the intersecting ridge line portion of the second end surface and the peripheral side surface so as to be 180 ° rotationally symmetric around the second axis with respect to the plurality of cutting edge sections on the first end surface side. The cutting insert (1) according to claim 1 or 2, wherein is formed. In the plan view of the cutting insert, the outline of the first end surface is such that the corner portion (7) and the substantially linear side portion (6) from which the main cutting edge extends are alternately and continuously arranged. Formed by,
Cutting insert (1) according to any one of claims 1 to 3.   In plan view of the cutting insert (1), at least a part of the wiping blade (10) and the corner blade (9) are provided in the corner portion (7) of the cutting insert (1). Cutting insert (1) according to any one of the preceding claims. In the plan view of the cutting insert (1), the corner portion (7) is formed symmetrically with respect to the bisector (C) of the corner portion (7),
In a single cutting edge section, the main cutting edge (8) extends to one side of the bisector (C) and at least half of the wiping edge (10) is the bisector (C Extending to the other side of
Cutting insert (1) according to claim 5. The wiping blade (10) is formed so as to gradually approach the intermediate surface (M) as it moves away from the corner blade (9).
Cutting insert (1) according to any one of claims 1 to 6. In the side view of the cutting insert (1) from the position along the bisector of the corner portion (7) in plan view of the cutting insert (1), the wiping blade (10) is the corner blade The inclination angle with respect to the intermediate surface on the side is formed so as to be larger than the inclination angle with respect to the intermediate surface on the anti-corner blade side,
Cutting insert (1) according to claim 7. In plan view of the cutting insert (1), the outer shape of the cutting insert (1) is a substantially equilateral triangle,
The cutting insert (1) is for right-angle shoulder cutting,
Cutting insert (1) according to any one of the preceding claims. It extends between the first end surface (2), the second end surface (3) disposed opposite to the first end surface (2), and between the first end surface (2) and the second end surface (3). A cutting insert (1) having an existing circumferential side (4),
A plurality of cutting edge sections (15) are formed in the intersecting ridge line portion between the first end surface (2) and the peripheral side surface (4),
The cutting edge section includes a main cutting edge (8), a wiping edge (10), and a corner cutting edge (9) connecting the main cutting edge and the wiping edge,
A connecting portion (11) is formed connecting the wiper blade (10) and the main cutting edge (8) of the adjacent cutting edge section;
In a plan view on the first end face side of the cutting insert, the corner blade (9) extends to a corner portion (7) of the first end face,
Of the second end surface (3), a surface parallel to the seating surface and located closer to the second end surface (3) side than the first end surface (2) is an intermediate surface (M). The main cutting edge (8) is inclined to approach the intermediate surface (M) as it moves away from the corner blade (9),
In the side view of the cutting insert (1), the connecting portion (11) has a concavely curved shape toward the intermediate surface (M), and the connection between the wiping blade (10) and the corner blade (9). When the imaginary line which connects a part and the connection part of the said wiping blade (10) and the said connection part (11) is defined, at least one part of the said wiping blade (10) was concave-curved rather than the said imaginary line Have a shape,
Cutting insert (1).

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