JP5639710B2 - Cutting insert, cutting tool, and method of manufacturing a cut product using the same - Google Patents

Description

  The present invention relates to a cutting insert, a cutting tool, and a method of manufacturing a cut workpiece using the cutting insert.

  Conventionally, as a cutting insert (hereinafter, also referred to as “insert”) used for face milling, an insert that can use both sides of a hexagonal shape has been proposed (for example, International Publication No. 2007/037733 A1). Issue).

  However, the insert of International Publication No. 2007/037733 A1 is disclosed in FIG. 1A and FIG. As shown in FIG. 1E, the configuration of the main cutting edge 16 and the auxiliary cutting edge 17 that are located across the corner cutting edge 20 is different, so that three corners of the hexagonal shape have the same rotation direction (for example, normal rotation). ), It was necessary to prepare separate inserts for reverse rotation and use them separately.

  On the other hand, there has been proposed a chip that can be used for both forward rotation and reverse rotation by making the cutting blade structures on both sides of the corner portion 4 the same (see, for example, JP-A-9-216113).

However, as shown in FIG. 2, in the chip of Japanese Patent Laid-Open No. 9-216113, the portion 10 mainly used during cutting is linearly inclined among the cutting blades, so that large cutting is performed during cutting. In the vicinity of the corner portion 4 to which the force is applied, there is a possibility that the cutting edge strength cannot be sufficiently ensured and is lost. This also applies to the insert of the above-mentioned International Publication No. 2007/037733 A1.
Therefore, an insert having both low cutting resistance and excellent fracture resistance is required.

  One of the objects of the present invention is to provide a cutting insert and a cutting tool having both a low cutting resistance and an excellent fracture resistance, and a method for producing a cut workpiece using the cutting insert.

  A cutting insert according to an embodiment of the present invention includes a polygonal upper surface, a lower surface having the same shape as the upper surface, a side surface connected to each of the upper surface and the lower surface, and a line of intersection between the upper surface and the side surface. An upper cutting edge located at a portion, and the upper surface alternately includes three main corners having a first inner angle and three sub-corners having a second inner angle larger than the first inner angle. The upper cutting edge includes a first sub-corner and a second sub-corner that are adjacent to the first main corner of the three sub-corners from the first main corner of the three main corners. In order toward each, a corner cutting edge, and a secondary cutting edge inclined at a first inclination angle toward the lower surface with reference to a vertical plane perpendicular to the central axis passing through the upper and lower surfaces as the distance from the corner cutting edge increases And the auxiliary cutting edge It has a main cutting edge which is inclined at a second inclination angle greater than the first inclination angle toward the lower surface with respect to the said vertical plane as al away.

  The cutting tool which concerns on embodiment of this invention is equipped with the cutting insert which concerns on embodiment mentioned above, and the holder to which the said cutting insert is attached, The said cutting insert is a said 1st main corner among the said upper cutting blades. The axial rake angle of the first main cutting section across the adjacent first sub-corner is positive, and the non-cut across the second main corner adjacent to the first sub-corner among the upper cutting edges. The axial rake angle of the cutting part is negative.

  The manufacturing method of the cut workpiece which concerns on embodiment of this invention is a process which rotates the cutting tool which concerns on embodiment mentioned above on the basis of the rotating shaft of the said holder, The said upper cutting blade of the said cutting tool which is rotating A step of contacting the surface of the work material, and a step of separating the cutting tool from the work material.

  According to the cutting insert which concerns on embodiment of this invention, the upper surface has alternately three main corners provided with the 1st interior angle, and 3 sub corners provided with the 2nd interior angle larger than the 1st interior angle. In addition, since it has an upper cutting edge of the same shape from one main corner to two sub-corners adjacent to both sides, each of the three main corners can be cut in both right-handed and left-handed Can be used.

  At the same time, the upper cutting edge is directed from the first main corner of the three main corners to each of the first sub-corner and the second sub-corner adjacent to the first main corner of the three sub-corners. In order, from the corner cutting edge, the secondary cutting edge inclined at the first inclination angle toward the lower surface with reference to a vertical plane perpendicular to the central axis passing through the upper and lower surfaces as the distance from the corner cutting edge, and the secondary cutting edge The main cutting edge which inclines with the 2nd inclination angle larger than a 1st inclination angle toward a lower surface on the basis of a perpendicular plane as it leaves | separates. That is, the upper cutting edge includes a corner cutting edge perpendicular to the central axis in a side view and a sub cutting edge and a main cutting edge that are inclined in two stages on the lower surface side. Therefore, in combination with the main corner having a relatively small first interior angle and the sub-corner having a relatively large second interior angle as described above, it is possible to combine low cutting resistance and excellent chipping resistance.

It is a figure which shows the cutting insert which concerns on embodiment of this invention, (a) is a perspective view, (b) is a top view (top view). It is a side view which shows the cutting insert shown in FIG. 1, (a) is a X1 arrow view, (b) is a X2 arrow view, (c) is a X3 arrow view. It is a figure which shows the 1st modification of the cutting insert of FIG. 1, (a) is a perspective view, (b) is a top view (top view). It is a figure which shows the cutting insert of FIG. 3, (a) is a Y1 arrow side view, (b) is a Y2 arrow side view, (c) is sectional drawing of the II line. It is a figure which shows the 2nd modification of the cutting insert of FIG. 1, (a) is a perspective view, (b) is a top view (top view). It is a figure which shows the cutting insert of FIG. 5, (a) is Z1 arrow side view, (b) is Z2 arrow side view, (c) is sectional drawing of the II-II line. It is a figure which shows the cutting tool which concerns on embodiment of this invention, (a) is a perspective view, (b) is a side view. It is the side view which expands and shows the attachment state of the cutting insert in the cutting tool of FIG. 7, (a) is the figure which looked at the cutting insert from the side surface, (b) is the figure which looked at the cutting insert from the upper surface. (A)-(c) is process drawing which shows the manufacturing method of the cut workpiece which concerns on 1st Embodiment of this invention. (A)-(c) is process drawing which shows the manufacturing method of the cut material which concerns on 2nd Embodiment of this invention.

<Cutting insert>
Hereinafter, the cutting insert which concerns on embodiment of this invention is demonstrated in detail with reference to FIG. 1 and FIG.

  As shown in FIGS. 1 and 2, the insert 1 of this embodiment is generally connected to a polygonal (hexagonal) upper surface 2, a lower surface 3 having the same shape as the upper surface 2, and each of the upper surface 2 and the lower surface 3. The side surface 4, the through-hole 6 (mounting hole) penetrating from the upper surface 2 to the lower surface 3, the upper cutting edge 5 located at the intersection of the upper surface 2 and the side surface 4, and the lower surface 3 And a lower cutting edge 5P located at the intersection with the side surface 4. For example, the insert 1 may be configured such that one side of the upper surface 2 is 5 mm to 100 mm and the thickness of the upper and lower surfaces 2 and 3 is 3 mm to 100 mm. As shown in FIG. 1, the through hole 6 of the present embodiment is located at the center of each of the upper surface 2 and the lower surface 3.

  The insert 1 of the present embodiment has a hexagonal shape (substantially hexagonal) as shown in FIG. The top view means a state in which the insert 1 is viewed from the top surface 2 side. Here, the hexagonal shape is not limited to a strict hexagonal shape (regular hexagonal shape), but is a concept including a slight deformation within a range where the function can be exhibited. That is, the hexagonal shape of the present embodiment includes, for example, a case where each side or each vertex has a slight curved shape.

  Further, the insert 1 has three main corners 21 (first to third main corners 21a to 21c) having a first inner angle α and a second inner angle β larger than the first inner angle α. Sub-corners 22 (first to third sub-corners 22a to 22c) are alternately provided. Similarly, the insert 1 has lower surfaces 3 alternately having three main corners 21 having a first inner angle α and three sub-corners 22 having a second inner angle β larger than the first inner angle α. Yes. Thus, since the insert 1 has the upper cutting edge 5 and the lower cutting edge 5P having the same shape from one main corner 21 toward two sub-corners 22 and 22 adjacent to both sides thereof, the upper surface 2 and the lower surface In each of the three main corners 21 in FIG. 3, cutting can be performed by rotating in both directions of the right hand and the left hand. That is, according to the insert 1 of the present embodiment, each of the three main corners 21 on the upper surface 2 and the lower surface 3 is used as a right hand and a left hand, so that it can be used as an insert having substantially six main corners. Is possible.

  Here, the first interior angle α is preferably substantially a right angle. “Substantially perpendicular” means substantially perpendicular. Specifically, the substantially right angle of the present embodiment includes a range of 90 ° ± 3 °. In particular, the first interior angle α is preferably larger than 90 °. In addition, the second interior angle β is preferably set within a range of 140 ° to 150 °. In addition, it is preferable that the length of each side is equal from a viewpoint of ensuring large length of the cutting blade which contributes to cutting, using all the sides for cutting.

  Further, in the insert 1 of the present embodiment, the upper cutting edge 5 is located over the entire circumference of the upper surface 2. Thereby, the insert 1 can use the three main corners 21 for cutting. In addition, when cutting is performed using the upper cutting edge 5 in this way, the lower surface 3 functions as a seating surface (mounting portion) for partly attaching to the holder 11 described later.

  The insert 1 according to the present embodiment is a so-called negative type in which both the upper surface 2 and the lower surface 3 can be used as surfaces for performing a scooping function, as shown in FIGS. 1 (a) and 2 (a). It is an insert. Therefore, when cutting using the lower cutting edge 5P, a part of the lower surface 3 can be used as a scoop surface and a part of the upper surface 2 can be used as a seating surface (mounting portion). That is, the insert 1 of the present embodiment has a configuration in which the upper surface 2 and the lower surface 3 have the same shape, and the upper and lower surfaces can be used for cutting. Hereinafter, the description regarding the upper surface 2 is also applied to the lower surface 3 unless otherwise specified.

Next, each component of the insert 1 of this embodiment is demonstrated in detail.
The upper surface 2 is a surface having a so-called scooping function for discharging chips, and in order from the upper cutting edge 5 inward, the scooping surface 23 is inclined to the lower surface 3 side, and is away from the lower surface 3 side. And a flat upper mounting portion 26 (sitting surface) substantially perpendicular to the central axis S1. “Inward” means the inside of the insert 1 with respect to the upper cutting edge 5 and means the through-hole 6 side (center axis S1 side). The central axis S1 is an axis that penetrates the upper and lower surfaces 2 and 3, and means an axis that becomes a rotation axis when the insert 1 is rotated in a top view.

  The rake face 23 is continuous with the upper cutting edge 5 as shown in FIG. Further, the rake face 23 is inclined downward at the third inclination angle θ3 toward the lower surface 3 with reference to the vertical plane S1b perpendicular to the central axis S1 from the upper cutting edge 5 toward the central axis S1 ( (Refer FIG.6 (c)). In the present embodiment, the rake face 23 is located over the entire circumference of the insert 1. Here, the third inclination angle θ3 is preferably set to 10 ° to 30 °.

  As shown in FIG. 1, the rising surface 24 is continuous with the rake surface 23, and is away from the lower surface 3 with respect to the vertical surface S <b> 1 b as it goes from the upper cutting edge 5 toward the central axis S <b> 1 (inward), that is, It is inclined upward at a fourth inclination angle θ4 (not shown). In the present embodiment, the rising surface 24 is located at a portion corresponding to the three sub corners 22. Here, the fourth inclination angle θ4 is preferably set to 40 ° to 70 °.

  As described above, in the insert 1 of the present embodiment, the rake face 23 is continuous with the upper mounting portion 26 at a portion corresponding to the three main corners 21 and is a rising surface at a portion corresponding to the three sub corners 22. 24 and the upper mounting part 26 are continued.

  In the insert 1 of the present embodiment, the upper placement portion 26 has a polygonal shape, particularly a triangular shape, when viewed from above as a whole. This also applies to the lower mounting portion 36 of the lower surface 3. That is, as shown in FIG. 2A, the lower surface 3 has a planar lower mounting portion 36, and the lower mounting portion 36 has a polygonal shape, particularly a triangular shape, when viewed from the lower surface as a whole. The bottom view means a state in which the insert 1 is viewed from the bottom surface 3 side.

  Here, the polygonal shape described above is not limited to the case of having a vertex in a strict sense. For example, a connection portion between sides is limited to the limit necessary to obtain a predetermined effect. This is a concept including a slightly curved configuration.

  Further, as shown in FIG. 1B, in the top view, the outer periphery of the through hole 6 is located inside a region surrounded by a straight line L1 connecting the three top portions 26t of the triangular upper mounting portion 26. . This also applies to the outer periphery of the through-hole 6 in the bottom view. In addition, although the top part 26t says the site | part corresponding to a polygonal vertex, as shown to a figure, it may mean the vicinity area | region of the vertex enclosed with the elliptical dotted line. This also applies to the following.

  Moreover, as shown in FIG.1 (b), it is preferable that the upper mounting part 26 has the three separation parts 26a spaced apart from each other. Thereby, when attaching to the holder 11, each of the three separating portions 26 a of the insert 1 can be brought into contact with the corresponding contact surface of the holder 11 separately, so that attachment stability to the holder 11 is improved. It becomes possible to improve. For example, even when the shape of the upper mounting portion 26 is deformed, for example, in the firing step of the manufacturing process of the insert 1, the three separating portions 26 a are independent from each other, and thus undergo another process such as polishing. It is possible to make the contact with the contact surface of the holder 11 relatively strong. This also applies to the lower mounting portion 36 of the lower surface 3. That is, the lower mounting part 36 preferably has three separation parts that are separated from each other.

  Each of the three separating portions 26a has a triangular shape in a top view. In particular, it is preferable that one triangular top portion of the separation portion 26 a is closest to the main corner 21. Thereby, it is possible to further improve the attachment stability to the holder 11. This also applies to the three separation portions on the lower surface 3. That is, each of the three separating portions on the lower surface 3 has a triangular shape when viewed from the lower surface, and in particular, it is preferable that one top portion of the triangular shape of the separating portion is closest to the main corner 21 on the lower surface 3.

  When the upper cutting blade 5 is used for cutting, the lower mounting portion 36 of the lower surface 3 is a surface that contacts the holder 11. The reverse is also true.

  The lower mounting portion 36 of the lower surface 3 has an end portion 36B positioned on the central axis S1 side with respect to the end portion 36A positioned on the lower cutting edge 5P side, the upper surface 2 side with respect to the vertical surface S1b, That is, it is located above (see FIG. 4). In other words, the lower mounting portion 36 has an outer peripheral region located outside the central region in the thickness direction of the insert 1. As a result, when attaching to the holder 11, the end 36A located on the lower cutting edge 5P side is relatively strongly brought into contact with the corresponding contact surface of the holder 11, and is located on the center axis S1 side. Since the end 36B that is present can also be brought into relatively weak contact with the corresponding contact surface of the holder 11, the attachment to the holder 11 by the end 36A located on the lower cutting edge 5P side is performed on the center axis S1 side. It is possible to assist by the end portion 36B located at the position, and it is possible to improve the attachment stability to the holder 11. In addition, it is preferable to set the inclination angle from the center area | region of the lower mounting part 36 to an outer peripheral area | region in 80 degrees-90 degrees.

  Further, as shown in FIG. 1, the upper surface 2 further has a recess 25 positioned around the through-hole 6 on the lower surface 3 side, that is, below the upper mounting portion 26, and the three separations described above. The portions 26 a are separated from each other via the through hole 6 and the recess 25. As a result, each of the three separating portions 26a can be brought into contact with the corresponding contact surface of the holder 11 more reliably, thereby further improving the attachment stability to the holder 11 as described above. Can be made. This also applies to the lower surface 3.

  As shown in FIG. 2, the upper cutting edge 5 has a corner cutting edge 51, a secondary cutting edge 52, and a main cutting edge 53. Specifically, as shown in FIGS. 1B and 2A, the upper cutting edge 5 is formed of, for example, the first main corner 21a to the three sub corners 22 out of the three main corners 21. In order toward each of the first sub-corner 22a and the second sub-corner 22b adjacent to the first main corner 21a, the lower the corner cutting edge 51, the lower the corner cutting edge 51, that is, with respect to the vertical plane S1b. The secondary cutting edge 52 that is inclined toward the lower surface 3 at the first inclination angle θ1 and the lower side from the auxiliary cutting edge 52, that is, from the first inclination angle θ1 toward the lower surface 3 with respect to the vertical surface S1b. Has a main cutting edge 53 that is inclined at a larger second inclination angle θ2. Therefore, the insert 1 of the present embodiment, in combination with the main corner 21 having the first inner angle α and the sub-corner 22 having the second inner angle β as described above, has both low cutting resistance and excellent fracture resistance. It becomes possible.

  Here, the first inclination angle θ1 is preferably set to 3 ° to 15 °, and the second inclination angle θ2 is preferably set to 7 ° to 19 °. In the present embodiment, the first inclination angle θ1 means an angle formed by the vertical plane S1b and the virtual extension line L2 of the auxiliary cutting edge 52, and the second inclination angle θ2 is the vertical plane S1b. It means the angle formed by the virtual extension line L3 of the main cutting edge 53. The virtual extension line L2 means a straight line obtained by extending the tangent at the starting point of the auxiliary cutting edge 52, that is, the end of the auxiliary cutting edge 52 located on the corner cutting edge 51 side. Similarly, the virtual extension line L3 means a straight line obtained by extending the tangent at the starting point of the main cutting edge 53, that is, the end of the main cutting edge 53 located on the sub cutting edge 52 side. To do.

  As shown in FIG. 2, the corner cutting edge 51 is located at the intersection of a later-described main corner side face 41 and the upper face 2 of the side face 4, and the upper cutting edge 5 is lost due to the cutting force applied during the cutting process. And has a curved shape in a top view. In the present embodiment, the corner cutting edge 51 is perpendicular to the central axis S1 and parallel to the vertical plane S1b.

  As shown in FIG. 2, the auxiliary cutting edge 52 is located on the corner cutting edge 51 side in the intersecting portion of the side face 4 between a first side face 42 to be described later and the upper face 2. Further, as shown in FIG. 1B, the auxiliary cutting edge 52 is a cutting edge having a role as the first and second main cutting portions 5a and 5c together with the main cutting edge 53. At the same time, the auxiliary cutting edge 52 is a cutting edge having a role of mainly improving the accuracy of the finished surface 102 of the work material 100 described later, a so-called wiping edge. In the present embodiment, the auxiliary cutting edge 52 is linear.

  As shown in FIG. 2, the main cutting edge 53 is located on the first sub-corner 22a side in the intersecting portion of the first side surface 42 and the upper surface 2, and plays a main role in chip generation in the cutting process. It has a cutting blade. In the present embodiment, the main cutting edge 53 is concave on the lower surface 3 side in a side view. The side view means a state in which the insert 1 is viewed from the side surface 4 side. In addition, it is preferable that the connection part 54 of the main cutting edge 53 and the sub cutting edge 52 is set so that it may curve in the direction away from the lower surface 3, ie, upward in the range of R1.0-R10.0.

  As described above, the upper cutting edge 5 is inclined toward the lower surface 3 as it goes to the corner cutting edge 51, the auxiliary cutting edge 52, and the main cutting edge 53, so that a high cutting edge strength is provided on the corner cutting edge 51 side. At the same time, it is possible to realize a low cutting resistance on the main cutting edge 53 side. Moreover, although the thickness of the insert 1 is decreasing as it goes to the corner cutting edge 51, the sub cutting edge 52, and the main cutting edge 53, the distance from the through-hole 6 to each cutting edge in top view becomes large in connection with it. Therefore, it is possible to ensure a high cutting edge strength in each cutting edge region.

  As with the upper cutting edge 5, the lower cutting edge 5P has a corner cutting edge 51P, a sub cutting edge 52P, and a main cutting edge 53P. The configuration of the corner cutting edge 51P, the auxiliary cutting edge 52P, and the main cutting edge 53P is the same as that of the corner cutting edge 51, the auxiliary cutting edge 52, and the main cutting edge 53.

  The side surface 4 is a surface that functions as a so-called escape portion for suppressing contact with the work material 100, and is perpendicular to the upper surface 2 and the lower surface 3 in this embodiment, as shown in FIG. 2. Therefore, compared to an insert having a clearance angle between the side surface and the upper surface 2 or the lower surface 3, the thickness of the insert 1 can be ensured, so that the insert 1 has excellent fracture resistance.

  Specifically, the side surface 4 connected to the hexagonal upper surface 2 has a main corner side surface 41 from the first main corner 21a toward the second main corner 21b as shown in FIG. The first side surface 42, the sub-corner side surface 43, and the second side surface 44 are provided in this order. The first side surface 42 and the second side surface 44 are both flat surfaces, and the main corner side surface 41 and the sub-corner side surface 43 are both curved surfaces.

  The through hole 6 has a role of fixing the insert 1 to a holder 11 described later. That is, the insert screw 12 (fixing member) is inserted into the through hole 6 and further screwed into the holder 11 to fix the insert 1 to the holder 11 and form the cutting tool 10. In addition, the central axis of the through-hole 6 exists in the same position as the central axis S1.

(First modification)
Next, a first modification of the insert 1 according to the above-described embodiment will be described in detail with reference to FIGS. 3 and 4.

  In addition, the basic structure of the insert 1 of this modification is equivalent to the insert 1 of the above-mentioned embodiment. Therefore, in FIGS. 3 and 4, the same components as those in FIGS. 1 and 2 described above are denoted by the same reference numerals, and the description thereof will be omitted. The explanation shall be given.

  In insert 1 of this modification, rake face 23 has convex part 23a in a portion corresponding to corner cutting edge 51, as shown in Drawing 3 and Drawing 4 (c). Accordingly, the generated chips can be curled relatively small by the convex portion 23a under the low cutting condition or the low feed condition, so that excellent chip discharging performance can be exhibited. In addition, it is preferable to arrange | position so that the whole convex part 23a may be settled in the area | region of the rake face 23. FIG. Further, as shown in FIG. 4C, it is preferable that the highest portion of the convex portion 23 a is located on the lower surface 3 side with respect to the upper cutting edge 5.

  In the above-described embodiment, the concave portion 25 located on the upper surface 2 has an integral shape surrounding the through hole 6. However, in the present modification, the concave portion 25 includes three separation portions 26 a. They are formed apart from each other at the separation positions. Thereby, since the area of the three separation parts 26a can be ensured larger, the attachment stability to the holder 11 can be improved.

(Second modification)
Next, the 2nd modification of the insert 1 which concerns on the above-mentioned embodiment is demonstrated in detail with reference to FIG. 5 and FIG.

  In addition, the basic structure of the insert 1 of this modification is equivalent to the insert 1 of the above-mentioned embodiment. Therefore, in FIG. 5 and FIG. 6, the same components as those in FIG. 1 and FIG. 2 described above are denoted by the same reference numerals, and the description thereof will be omitted. The explanation shall be given.

  In the insert 1 of this modification, as shown in FIG. 5, the upper placement portion 26 has a hexagonal shape when viewed from above. Thereby, since it can attach to the holder 11 using six hexagonal top parts 26t, the attachment stability with respect to the holder 11 can be improved. In addition, although the recessed part 25 exists in the upper surface 2, the upper mounting part 26 of this modification is formed integrally without being separated.

  The six top portions 26t of the upper mounting portion 26 are composed of three main top portions 26t1 positioned corresponding to the three main corners 21 and three sub-top portions positioned corresponding to the three sub corners 22. 26t2. Thus, since each top part 26t is located corresponding to the corner part which receives a comparatively big cutting force at the time of cutting, chatter vibration can be reduced by attaching to the holder 11 in the said part. Damage to the upper cutting edge 5 can be reduced. The same applies to these points and the lower mounting portion 36.

  Here, in the insert 1 of this modification, the upper surface 2 does not have the rising surface 24 as in the above-described embodiment (see FIG. 1). In other words, as shown in FIG. 5A, the rake face 23 of this modification is continuous with the upper mounting portion 26. Thereby, since the area of the upper mounting part 26 can be ensured more, the attachment stability to the holder 11 can be improved. That is, for example, since the distance from the main top portion 26t1 of the upper placement portion 26 to the corner cutting edge 51 can be reduced, it is possible to prevent the insert 1 from being damaged during the cutting process.

  In particular, in the present modification, as shown in FIG. 6C, the rake face 23 includes two stages of first and second inclined portions 23b and 23c. The first and second inclined portions 23b and 23c have different inclination angles. And the inclination angle of the 1st inclination part 23b located in the upper cutting-blade 5 side which mainly exhibits the function of a scoop is small, and the inclination angle of the 2nd inclination part 23c located in the upper mounting part 26 side is large. Therefore, the top portion 26 t of the upper placement portion 26 can be brought closer to the upper cutting blade 5.

  Moreover, in the insert 1 of this modification, the three main top portions 26t1 have a larger distance from the central axis S1 than the three sub-top portions 26t2. That is, as shown in FIG. 5B, the main top portion 26t1 and the sub-top portion 26t2 of this modification satisfy the relationship D1> D2. As a result, the cutting edge regions functioning as the first and second main cutting portions 5a and 5c can be brought into contact with the holder 11 using the three main top portions 26t1 located at locations relatively far from the central axis S1. At the same time, since the other sub-tops 26t2 can be used to contact the holder 11 in the other areas, the three main tops 26t1 can be attached to the holder 11 by the three sub-tops 26t2. The attachment stability with respect to the holder 11 can be improved. This also applies to the main top portion 26t1 and the sub-top portion 26t2 in the lower placement portion 36.

  Further, in the lower mounting portion 36 of the lower surface 3, the three main top portions 26t1 are located farther from the upper surface 2 with respect to the vertical surface S1b, that is, lower than the three sub-top portions 26t2. Thereby, when attaching to the holder 11 with the upper surface 2 facing forward in the rotation direction, the three main top portions 26t1 can be brought into relatively strong contact with the corresponding contact surfaces of the holder 11, and Since the three sub-tops 26t2 can also be brought into relatively weak contact with the corresponding contact surfaces of the holder 11, the three sub-tops 26t2 can assist the attachment to the holder 11 by the three main tops 26t1. It is possible to improve the attachment stability to the holder 11.

  Moreover, in the insert 1 of this modification, the upper mounting part 26 of the upper surface 2 is located on the lower surface 3 side (downward) from any part of the upper cutting blade 5 in a side view as shown in FIG. Yes. Thereby, it is possible to reduce the collision of the chips generated by the upper cutting blade 5 with the upper placement portion 26 during the cutting process, and it is possible to suppress damage to the upper placement portion 26. Specifically, the insert 1 of this modification has the same thickness between the upper mounting portion 26 and the lower mounting portion 36 as compared to the insert 1 of the above-described embodiment, whereas the upper surface 2 In both the maximum thickness and the minimum thickness in the thickness direction from the lower surface 3 to the lower surface 3, the thickness is set to be larger than the thickness between the upper mounting portion 26 and the lower mounting portion 36. Thereby, since the distance between the upper cutting blade 5 and the upper mounting part 26 becomes large, the space for producing | generating a chip can be ensured large, and the discharge property of a chip can be improved. Further, for example, when the shape of the upper placement portion 26 is deformed, for example, in the firing step of the manufacturing process of the insert 1, the upper placement portion 26 is positioned on the lower surface 3 side with respect to the upper cutting edge 5 as described above. However, it is difficult to shape by polishing, but by providing the upper mounting portion 26 with an inclination, it is possible to stably contact the contact surface of the holder 11 without performing the polishing. Is possible.

<Cutting tools>
Next, the cutting tool which concerns on embodiment of this invention is demonstrated in detail with reference to FIG. 7 and FIG.

  As shown in FIG. 7, the cutting tool 10 of the present embodiment includes a plurality of inserts 1 described above and a holder 11 to which the plurality of inserts 1 are attached using a fixing member.

  The holder 11 has a plurality of insert pockets 11a at its outer peripheral tip. And the insert 1 is attached to the outer peripheral position in each insert pocket 11a. Specifically, when the cutting tool 10 is rotated in the direction of arrow A in FIG. 7A, the insert 1 has the upper surface (rake surface) 2 facing the front side of the arrow A that is the rotation direction, and the holder 1 11 is attached so that the main cutting edge 53 is positioned on the outermost periphery of the motor 11. As an attachment method, the plurality of inserts 1 are respectively fixed to the holder 11 by inserting attachment screws 12 (fixing members) into the respective through holes 6 of the plurality of inserts 1 and screwing them into the holders 11.

  In the present embodiment, as shown in FIG. 8A, the insert 1 is adjacent to the first main corner 21a of the upper cutting edge 5 on the basis of the parallel surface S2a parallel to the rotation axis S2 of the holder 11. The axial rake angle θa of the first main cutting portion 5a across the first sub-corner 22a is positive, and the non-cut across the second main corner 21b adjacent to the first sub-corner 22a of the upper cutting edge 5 The cutting part 5b is attached to the holder 11 in such a state that the axial rake angle θb is negative.

  Here, the first main cutting portion 5a includes a sub cutting edge 52 and a main cutting edge 53. In this embodiment, the axial rake angle θa is positive in both the sub cutting edge 52 and the main cutting edge 53. is there. For example, the axial rake angle of the sub cutting edge 52 is preferably set to 0 ° to 10 °, and the axial rake angle of the main cutting edge 53 is preferably set to 5 ° to 20 °. Note that the axial rake angle θa, for example, for a curved cutting edge like the main cutting edge 53, extends the tangent at the starting point of the main cutting edge 53, that is, the end located on the sub cutting edge 52 side. What is necessary is just to measure using the straight line L4. In addition, the axial rake angle θb may be measured using, for example, a straight line L5 obtained by extending a tangent at the start point of the non-cutting portion 5b, that is, the end located on the first sub-corner 22a side.

  8A, the insert 1 is in a state where the axial rake angle θc of the straight line L6 connecting the first main corner 21a and the second main corner 21b of the upper cutting edge 5 is negative. And attached to the holder 11. In other words, the axial rake angle as a whole including the first main cutting portion 5a and the non-cutting portion 5b is negative.

  The cutting tool 10 is configured by attaching the insert 1 to the holder 11 as described above. By rotating such a cutting tool 10 in the direction of arrow A, it is possible to perform cutting such as face milling and plunge machining on the work material 100 as described later.

  For example, as shown in FIG. 8 (b), when performing face milling, the workpiece 100 is cut using the first main cutting portion 5a of the insert 1 to form the cutting surface 101, and the secondary cutting is performed. The finished surface 102 can be formed by cutting the workpiece 100 using the cutting edge 52. At this time, the auxiliary cutting edge 52 is set in a substantially parallel relationship with respect to the vertical surface S2b perpendicular to the rotation axis S2 of the holder 11.

<Manufacturing method of cut product>
Next, the manufacturing method of the cut workpiece which concerns on 1st, 2nd embodiment of this invention is demonstrated in detail with reference to FIG. 9 and FIG.

  The manufacturing method of the cut workpiece of the first and second embodiments includes a step of rotating the cutting tool 10 described above with reference to the rotation axis S2 of the holder 11, and an upper cutting edge 5 of the rotating cutting tool 10 covered. A step of contacting the surface of the work material 100 and a step of separating the cutting tool 10 from the work material 100. Hereinafter, each embodiment will be described in detail.

(First embodiment)
A so-called face milling process will be described in detail with reference to FIG. 9 as an example of a method for manufacturing a cut product according to the first embodiment.

  The manufacturing method of the cut workpiece according to the present embodiment includes the following steps (i) to (iii). In addition, in the following description, when the order which performs each process is not specified, the order may be changed suitably.

  (I) A step of rotating the cutting tool 10 in the direction of arrow A around the rotation axis S2 of the holder 11 (cutting tool 10) as shown in FIG. Then, the cutting tool 10 is moved in the direction of the arrow B so as to approach the work material 100.

  (Ii) A step of bringing the upper cutting edge 5 of the rotating cutting tool 10 into contact with the surface of the work material 100 as shown in FIG. Here, in this embodiment, the process (ii) has the following three processes.

  First, a step of moving the rotating cutting tool 10 in the direction of arrow C, which is a direction perpendicular to the rotation axis S2. Accordingly, face milling can be performed on the work material 100.

  Secondly, the first main cutting portion 5 a extending from the first main corner 21 a to the first sub-corner 22 a adjacent to the upper cutting edge 5 of the rotating cutting tool 10 is formed on the surface of the work material 100. The process of making it contact. As a result, the cut surface of the work material 100 cut in contact with the first main cutting portion 5a becomes a cut surface 101 as shown in FIG. 9B.

  Thirdly, the auxiliary cutting edge 52 located between the first main corner 21a and the second auxiliary corner 22b in the upper cutting edge 5 of the rotating cutting tool 10 is replaced with the first main cutting portion 5a. The process of making it contact the work surface of the work material 100 formed by contacting. As a result, the portion of the work surface of the work material 100 cut by the first main cutting portion 5a in the second step described above that is left uncut without being directly cut by the first main cutting portion 5a is sub-cut. Smoothed by the blade 52, a finished surface 102 as shown in FIG.

  (Iii) A step of moving the cutting tool 10 as it is in the direction of arrow C as shown in FIG. 9C to separate the cutting tool 10 from the work material 100.

  Through the above steps, a cut workpiece 110 is manufactured by cutting the workpiece 100 into a desired shape as shown in FIG.

  Moreover, when performing cutting continuously, the process which maintains the state which rotated the cutting tool 10, for example, and makes the upper cutting blade 5 of the cutting tool 10 contact the different location of the workpiece 100 is carried out. Repeat it. When the main corner 21 of the upper cutting edge 5 used for cutting is worn, the main corner 21 of the unused upper cutting edge 5 is used by rotating the insert 1 120 ° with respect to the central axis S1. That's fine. Moreover, in this embodiment, since the one main corner 21 of the insert 1 can be used for reverse-handed cutting by rotating the rotation direction of the cutting tool 10 in the direction opposite to the arrow A, 3 By using each of the main corners 21 for both the right hand and the left hand, it can be used as an insert having substantially six main corners. In addition, by changing the rotation direction of the cutting tool 10 in the direction opposite to the arrow A, the auxiliary cutting edge 52 in the first main cutting portion 5a has a role as a cutting edge for forming the finished surface 102. In the present embodiment, the upper cutting edge 5 has been described, but the same applies to the lower cutting edge 5P.

  In addition, each above-mentioned process can be deform | transformed as follows. For example, in the step (i), the work material 100 may be rotated while the cutting tool 10 is fixed. The cutting tool 10 and the work material 100 may be relatively close to each other. For example, the work material 100 may be close to the cutting tool 10. Similarly, in the step (iii), the work material 100 and the cutting tool 10 need only be relatively distant from each other. For example, the work material 100 may be kept away from the cutting tool 10 held at a predetermined position. Good. The same applies to the second embodiment described below.

(Second Embodiment)
Next, as a method for manufacturing a cut workpiece according to the second embodiment, a so-called plunge process (butting process) will be described as an example with reference to FIG.

  The manufacturing method of the cut workpiece according to the present embodiment includes the following steps (i) to (iii). In addition, in the following description, when the order which performs each process is not specified, the order may be changed suitably.

  (I) A step of rotating the cutting tool 10 in the direction of arrow A about the rotation axis S2 of the holder 11 (cutting tool 10) as shown in FIG. Then, the cutting tool 10 is moved in the direction of the arrow D so as to approach the work material 100.

  (Ii) A step of bringing the upper cutting edge 5 of the rotating cutting tool 10 into contact with the surface of the work material 100 as shown in FIG. Here, in this embodiment, the process (ii) has the following three processes.

  First, a step of moving the rotating cutting tool 10 in the direction of arrow D, which is a direction parallel to the rotation axis S2. Thereby, plunge machining can be performed on the work material 100.

  Secondly, the second main cutting portion 5c extending from the first main corner 21a to the second sub corner 22b adjacent to the upper cutting edge 5 of the rotating cutting tool 10 is formed on the surface of the work material 100. The process of making it contact. Thereby, the cut surface of the work material 100 cut in contact with the second main cutting portion 5c becomes a cut surface 101 as shown in FIG.

  Thirdly, the secondary cutting edge 52 located between the first primary corner 21a and the first secondary corner 22a in the upper cutting edge 5 of the rotating cutting tool 10 is replaced with the second primary cutting portion 5c. The process of making it contact the work surface of the work material 100 formed by contacting. As a result, the portion of the work surface of the work material 100 cut by the second main cutting portion 5c in the second step described above that is left uncut without being directly cut by the second main cutting portion 5c is sub-cut. Smoothed by the blade 52, a finished surface 102 as shown in FIG.

  (Iii) A step of moving the cutting tool 10 in the direction of arrow E and separating the cutting tool 10 from the work material 100 as shown in FIG.

  Through the above steps, a cut workpiece 110 is manufactured by cutting the work material 100 into a desired shape as shown in FIG.

  Moreover, what is necessary is just to carry out similarly to the above-mentioned 1st Embodiment, when performing cutting continuously.

  As mentioned above, although some embodiment which concerns on this invention was illustrated, this invention is not limited to embodiment mentioned above, It cannot be overemphasized that it can be made arbitrary, unless it deviates from the summary of this invention. .

  For example, although not specifically described in the insert 1 according to the above-described embodiment, the colors of the upper surface 2 and the lower surface 3 may be different from each other. Specifically, for example, when the insert body is a cemented carbide showing a silver color, it is preferable to cover one of the upper surface 2 and the lower surface 3 with, for example, a titanium nitride (TiN) showing a gold color. In the negative-type insert, both the upper surface 2 and the lower surface 3 function as rake surfaces, which may cause an erroneous mounting of the insert. When either one of the upper surface 2 and the lower surface 3 is coated with TiN, the surface coated with TiN and the surface not coated have different colors. Therefore, each surface can be clearly distinguished, and misidentification when the insert 1 is attached can be suppressed. Here, the coating target surface of either the upper surface 2 or the lower surface 3 does not need to cover the entire surface. The effect of can be obtained. Note that the material used for the coating is not limited to TiN as long as the color difference between the upper surface 2 and the lower surface 3 can be recognized. For example, when the insert body is a cemented carbide, titanium carbonitride (TiCN) showing a bright reddish brown, titanium nitride aluminum (TiAlN) showing a dark reddish brown can also be employed.

  Moreover, in the insert 1 which concerns on the above-mentioned embodiment, although the structure which has the three separation parts 26a in which the upper mounting part 26 was mutually spaced apart was demonstrated, it replaced with this and as long as the same effect can be acquired. You may employ | adopt the structure which connects the three isolation | separation parts 26a in the mutually adjacent site | part.

  Further, although not specifically described in the insert 1 according to the above-described embodiment, the upper cutting edge 5 may have a land (not shown) substantially parallel to the vertical surface S1b. As a result, the strength of the upper cutting edge 5 can be improved, and it can be suitably used even under so-called heavy cutting processing conditions.

  Moreover, in the insert 1 which concerns on the above-mentioned embodiment, although the structure where the upper surface 2 was hexagonal shape was demonstrated, you may make it the structure whose upper surface 2 is other polygonal shapes other than hexagonal shape.

Claims (25)

A polygonal top surface;
A lower surface having the same shape as the upper surface;
A side surface connected to each of the upper surface and the lower surface;
An upper cutting edge located at the intersection of the upper surface and the side surface,
The upper surface alternately includes three main corners having a first interior angle and three sub-corners having a second interior angle larger than the first interior angle,
The upper cutting edge is directed from a first main corner of the three main corners to each of a first sub corner and a second sub corner adjacent to the first main corner of the three sub corners. In turn, a corner cutting edge, a secondary cutting edge that is inclined at a first inclination angle toward the lower surface with reference to a vertical plane perpendicular to the central axis that penetrates the upper and lower surfaces as the distance from the corner cutting edge increases, and Having a main cutting edge that is inclined at a second inclination angle that is larger than the first inclination angle toward the lower surface with reference to the vertical plane as the distance from the sub cutting edge increases ,
The lower surface has a planar lower mounting portion, and the lower mounting portion is polygonal in bottom view,
The polygonal lower mounting portion has six tops,
The six tops have three main tops positioned corresponding to the three main corners on the lower surface, and three sub-tops positioned corresponding to the three sub-corners on the lower surface. ,
The three main top portions are located on a side farther from the top surface with respect to the vertical surface than the three sub top portions , the cutting insert. A polygonal top surface;
A lower surface having the same shape as the upper surface;
A side surface connected to each of the upper surface and the lower surface;
An upper cutting edge located at the intersection of the upper surface and the side surface,
The upper surface alternately includes three main corners having a first interior angle and three sub-corners having a second interior angle larger than the first interior angle,
The upper cutting edge is directed from a first main corner of the three main corners to each of a first sub corner and a second sub corner adjacent to the first main corner of the three sub corners. In turn, a corner cutting edge, a secondary cutting edge that is inclined at a first inclination angle toward the lower surface with reference to a vertical plane perpendicular to the central axis that penetrates the upper and lower surfaces as the distance from the corner cutting edge increases, and Having a main cutting edge that is inclined at a second inclination angle that is larger than the first inclination angle toward the lower surface with reference to the vertical plane as the distance from the sub cutting edge increases ,
The lower surface has a planar lower mounting portion, and the lower mounting portion is polygonal in bottom view,
Further comprising a lower cutting edge located at the intersection of the lower surface and the side surface,
The lower mounting portion has a cutting insert in which an end portion positioned on the central axis side is positioned on the upper surface side with respect to the vertical plane as compared with an end portion positioned on the lower cutting edge side. . The cutting insert according to claim 1 or 2 , wherein the corner cutting edge is parallel to the vertical plane. The cutting insert according to any one of claims 1 to 3, wherein the main cutting edge is concave on the lower surface side in a side view. The cutting insert according to any one of claims 1 to 4 , wherein the auxiliary cutting edge is linear. The cutting insert according to any one of claims 1 to 5 , wherein the first inner angle is substantially a right angle. The cutting insert according to claim 6 , wherein the first interior angle is greater than 90 °. Cutting insert according to any one of claims 1 to 7, further comprising a through hole, which penetrates to the lower surface from the upper surface. The cutting insert according to any one of claims 1 to 8 , wherein the lower mounting portion has a triangular shape in a bottom view.   The cutting insert according to claim 9, wherein the lower mounting part has three separation parts spaced apart from each other. The lower surface further includes a recess positioned on the upper surface side of the lower mounting portion around the through hole,
The cutting insert according to claim 10, wherein the three separating portions are spaced apart from each other via the through hole and the concave portion.   The cutting insert according to claim 10 or 11, wherein each of the three separation portions has a triangular shape in a bottom view.   The cutting insert according to claim 12, wherein each of the three separation portions has one triangular top portion closest to a main corner on the lower surface in a bottom view.   The cutting according to any one of claims 9 to 13, wherein an outer periphery of the through hole is located inside a region surrounded by a straight line connecting the three top portions of the triangular mounting portion in a bottom view. insert. The three main apex than said three sub-top, a large distance from the central axis, the cutting insert according to claim 1. The upper surface is continuous with the upper cutting edge, and a rake surface that is inclined at a third inclination angle toward the lower surface with respect to the vertical surface as it goes from the upper cutting edge toward the central axis, The cutting insert according to any one of claims 1 to 15 , further comprising: The cutting insert according to claim 16 , wherein the rake face has a convex portion at a portion corresponding to the corner cutting edge. The upper surface is continuous with the rake face, and rises at a fourth inclination angle in a direction away from the lower surface with respect to the vertical surface as it goes inward from the upper cutting edge, The cutting insert according to claim 16 or 17 , further comprising: The upper surface further includes a planar upper mounting portion,
The rake face is continuous with the upper placement portion at a portion corresponding to the three main corners, and is continuous with the upper placement portion via the rising surface at a portion corresponding to the three sub-corners. The cutting insert according to claim 18 . The top surface has the mounting portion on the planar, further, the upper mounting portion in the side view is located on the lower surface side from any part of the Kamigiri blade, any claim 1 to 19 Cutting insert according to crab. The cutting insert according to any one of claims 1 to 20 ,
A holder to which the cutting insert is attached,
The cutting insert has a positive axial rake angle of a first main cutting portion extending from the first main corner to the first sub-corner adjacent to the first main corner, and among the upper cutting blades. A cutting tool in which an axial rake angle of a non-cutting portion extending from the first sub-corner to the adjacent second main corner is negative. The cutting tool according to claim 21 , wherein the cutting insert has a negative linear rake angle connecting the first main corner and the second main corner of the upper cutting edge. The step of rotating the cutting tool according to claim 21 or 22 on the basis of the rotation axis of the holder;
Contacting the upper cutting edge of the rotating cutting tool with the surface of the work material;
And a step of separating the cutting tool from the work material. The step of bringing the upper cutting edge into contact with the surface of the work material,
Moving the rotating cutting tool in a direction perpendicular to the axis of rotation;
Contacting the first main cutting portion across the first sub-corner adjacent to the first main corner of the upper cutting edge of the rotating cutting tool with the surface of the work material;
By contacting the sub cutting edge located between the first main corner and the second sub corner of the upper cutting edge of the rotating cutting tool with the first main cutting portion. The manufacturing method of the cut workpiece of Claim 23 which has the process made to contact the cut surface of the formed said cut material. The step of bringing the upper cutting edge into contact with the surface of the work material,
Moving the rotating cutting tool in a direction parallel to the rotation axis;
A step of bringing the second main cutting portion across the second sub-corner adjacent to the first main corner out of the upper cutting edge of the rotating cutting tool into contact with the surface of the work material;
By contacting the sub cutting edge located between the first main corner and the first sub corner of the upper cutting edge of the rotating cutting tool with the second main cutting portion. The manufacturing method of the cut workpiece of Claim 23 which has the process made to contact the cut surface of the formed said cut material.

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