JP6352639B2 - Cutting insert, cutting tool, and method of manufacturing cut workpiece - Google Patents

Description

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

  As a cutting tool used for cutting a work material such as metal, a throw-away tip described in Patent Document 1 is known. The chip described in Patent Document 1 has a cutting edge including an arcuate cutting edge portion and a linear cutting edge portion. Further, in order to increase the strength of the cutting edge, chamfering (honing) is continuously performed along the cutting edge. In Patent Document 1, honing is performed so that a cutting edge ridge line where a rake face and a flank, which are regions where cutting edges are formed, has a convex curve shape in a cross section perpendicular to the cutting edges.

International Publication No. 2012/023325

  In the case of performing the cutting process using only the arc-shaped cutting blade, there is no particular problem even if the honing process is performed so as to have a convex curve shape as described above. However, when the cutting edge includes a wiper cutting edge in order to reduce the surface roughness of the finished surface of the work material, the honing process has a problem. This is because the strength of the cutting edge can be increased by performing the honing process so as to have a convex curve shape, but the sharpness of the cutting edge is lowered. When the sharpness of the cutting edge is lowered, it becomes difficult to make the wiper cutting edge function well.

  The present invention has been made in view of the above-described problems, and provides a cutting insert capable of causing a wiper cutting blade to function satisfactorily while maintaining the strength of the cutting edge when the cutting blade has a wiper cutting blade. It is in.

The cutting insert based on 1 aspect of this invention is the cutting edge provided in the ridgeline which the upper surface of a polygonal shape, a lower surface, the side surface located between the said upper surface and the said lower surface, and the said upper surface and the said side surface cross | intersect And. The cutting blade includes a corner cutting blade formed at a position corresponding to a corner portion on the upper surface, and a pair of wiper cutting blades positioned on both sides of the corner cutting blade. Then, in a cross section perpendicular to the upper surface and passing through the corner cutting edge, a region where the upper surface and the side surface intersect with each other has a convex curve shape and a first honing surface is formed so as to be smoothly connected to the side surface. In a cross section that is orthogonal to the upper surface and passes through the wiper cutting edge, at least a portion including the upper end continuous with the wiper cutting edge in the side surface is a linear shape, and the upper surface and the side surface intersect each other Has a convex curve shape and is characterized in that a second honing surface is formed so as to intersect the side surface.

In the cutting insert of the aspect described above, the cutting edge has a corner cutting edge and a wiper cutting edge, and honing is performed on the areas where the corner cutting edge and the wiper cutting edge are formed. However, it is not simply a honing process, but in the area where the corner cutting edge is formed, it is a convex curve shape at the intersection of the upper surface and the side surface so that it smoothly connects to the side surface. In the region where the first honing surface is formed, and in the region where the wiper cutting edge is formed, at least the portion including the upper end continuous with the wiper cutting blade on the side surface is linear, and the upper surface and the side surface The second honing surface is formed so as to have a convex curve shape and intersect the side surface in a region where the Therefore, the sharpness of the wiper cutting edge can be improved while increasing the strength of the corner cutting edge.

It is a perspective view which shows the cutting insert of the 1st Embodiment of this invention. It is the perspective view which expanded the area | region A in the cutting insert shown in FIG. It is a top view of the cutting insert shown in FIG. It is sectional drawing of the B1-B1 cross section in the cutting insert shown in FIG. It is sectional drawing of the B2-B2 cross section in the cutting insert shown in FIG. It is sectional drawing of a B3-B3 cross section in the cutting insert shown in FIG. It is a perspective view which shows the cutting tool of one Embodiment of this invention. (A)-(c) is the schematic which shows 1 process of the manufacturing method of the cut workpiece of one Embodiment of this invention, respectively.

<Cutting insert>
Hereinafter, the cutting insert of one embodiment is explained in detail using a drawing. However, in the drawings referred to below, for convenience of explanation, among the constituent members of the embodiment, only the main members necessary for explaining the present invention are shown in a simplified manner. Therefore, the cutting insert of the present invention may include any component not shown in the drawings to which the present specification refers. Moreover, the dimension of the member in each figure does not represent the dimension of an actual structural member, the dimension ratio of each member, etc. faithfully.

  The cutting insert 1 (hereinafter also simply referred to as the insert 1) of the present embodiment includes an upper surface 3, a lower surface 5, a side surface 7, a cutting edge 11 and a through hole 9. Examples of the material of the insert 1 include cemented carbide or cermet. As the composition of the cemented carbide, for example, WC-Co produced by adding cobalt (Co) powder to tungsten carbide (WC) and sintering, and WC-Co obtained by adding titanium carbide (TiC) to WC-Co. There is WC-TiC-TaC-Co in which tantalum carbide (TaC) is added to TiC-Co or WC-TiC-Co. The cermet is a sintered composite material in which a metal is combined with a ceramic component, and specifically includes a titanium compound mainly composed of titanium carbide (TiC) or titanium nitride (TiN).

The surface of the insert 1 may be coated with a film using a chemical vapor deposition (CVD) method or a physical vapor deposition (PVD) method. Examples of the composition of the coating include titanium carbide (TiC), titanium nitride (TiN), titanium carbonitride (TiCN), and alumina (Al ₂ O ₃ ).

  The upper surface 3 has a polygonal shape, and has a substantially rectangular shape in the present embodiment. Here, the polygonal shape does not mean strictly a polygonal shape. For example, the corner portions on the upper surface 3 in the present embodiment are not strict corners, but are rounded. Moreover, the side part located so that an adjacent corner | angular part may be connected does not need to become exactly linear shape. For example, it may have a shape that slightly protrudes outward.

The lower surface 5 is a surface located on the side opposite to the upper surface 3 and functions as a seating surface for the insert pocket 103 when the insert 1 is attached to the holder. The lower surface 5 in the present embodiment has a polygonal shape, specifically a substantially rectangular shape, like the upper surface 3. At this time, the lower surface 5 is configured to be slightly smaller than the upper surface 3. Further, the lower surface 5 in the present embodiment has a flat surface shape.

  The shapes of the upper surface 3 and the lower surface 5 are not limited to the above-described form. In the insert 1 of the present embodiment, the shape of the upper surface 3 when viewed from the upper surface is substantially rectangular. For example, the shape of the upper surface 3 when viewed from the upper surface is a polygon such as a triangle, pentagon, hexagon, or octagon. It may be a shape.

  The side surface 7 is located between the upper surface 3 and the lower surface 5 and is connected to the upper surface 3 and the lower surface 5. As described above, since the lower surface 5 is slightly smaller than the upper surface 3, the region connected to the upper surface 3 on the side surface 7 is smaller than the region connected to the lower surface 5 on the side surface 7 when viewed in plan. Located on the outside. Therefore, the side surface 7 is configured to be inclined so as to approach the central axis of the through hole 9 from the portion close to the upper surface 3 toward the portion close to the lower surface 5. In the present embodiment, the side surface 7 is formed to have a linear shape in a cross section parallel to the central axis O1.

  The maximum width when the top surface 3 of the insert 1 of the present embodiment is viewed from above is 6 to 25 mm. The height from the lower surface 5 to the upper surface 3 is 1 to 10 mm. Here, the height from the lower surface 5 to the upper surface 3 means a width in a direction parallel to the central axis O <b> 1 between the upper end of the upper surface 3 and the lower end of the lower surface 5.

  The cutting edge 11 is provided on a ridge line where the upper surface 3 and the side surface 7 intersect. The cutting edge 11 is used for cutting a work material in cutting. The insert 1 of the present embodiment has a configuration in which a cutting edge 11 is formed at a part of a ridge line where the upper surface 3 and the side surface 7 intersect, but the configuration of the cutting blade 11 is particularly limited to such a form. is not. For example, the cutting edge 11 may be formed on the entire ridge line where the upper surface 3 and the side surface 7 intersect.

  The upper surface 3 has a rake surface 13. The rake face 13 is provided along the cutting edge 11. The rake face 13 plays a role of scooping off chips cut by the cutting edge 11. Therefore, chips of the work material flow on the surface of the rake face 13. The rake face 13 is inclined so that the height from the lower face 5 decreases as the distance from the cutting edge 11 increases, in order to scoop the chips well. In other words, in the insert 1 of this embodiment, the rake face 13 is an inclined surface that is inclined so as to approach the lower surface 5 as it approaches the through hole 9. The rake face 13 is formed to have a linear shape in a cross section parallel to the central axis O1.

  In the insert 1 of this embodiment, although not shown, there is no problem even if the upper surface 3 has a configuration other than the rake surface 13. For example, a land surface (not shown) provided so as to surround the rake face 13, or located inside the rake face 13, and inclined so that the height from the lower face 5 increases as the distance from the rake face 13 increases. It may have a rising surface (not shown).

  The insert 1 of the present embodiment has a through hole 9 formed from the center of the upper surface 3 toward the center of the lower surface 5. The through hole 9 is provided for inserting a screw when the insert 1 is fixed to the holder of the cutting tool with a screw. The lower surface 5 in the present embodiment is a flat surface, and the direction in which the central axis O1 of the through hole 9 extends, in other words, the through direction is orthogonal to the lower surface 5.

As shown in FIGS. 2 and 3, the cutting edge 11 has a corner cutting edge 15 and a wiper cutting edge 17. The corner cutting edge 15 is formed at a position corresponding to the corner of the upper surface 3. The corners on the upper surface 3 in the present embodiment have a rounded shape. Therefore, corner cutting edge 15
Has an arc shape protruding outward when viewed from above. The corner cutting edge 15 functions as the main cutting edge 11 when cutting a workpiece. 2 is an enlarged top view of the region A in the cutting insert 1 shown in FIG. 1, and is an enlarged view of the vicinity of the corner portion of the upper surface 3.

  Further, the wiper cutting edge 17 is located adjacent to the corner cutting edge 15. The wiper cutting edge 17 is substantially linear when viewed from above. The wiper cutting edge 17 is a cutting edge 11 used to reduce the finished surface roughness of the work material, and is positioned so as to be substantially parallel to the finished surface of the work material in the cutting process.

  In the present embodiment, the pair of wiper cutting edges 17 are positioned so as to be adjacent to the corner cutting edges 15, respectively. In other words, the pair of wiper cutting edges 17 are positioned so as to sandwich the corner cutting edge 15 therebetween. Thus, when the cutting edge 11 has a pair of wiper cutting edges 17, the insert 1 can be used in both right-handed and left-handed cutting tools.

  In a region where the upper surface 3 and the side surface 7 intersect and where the cutting edge 11 is formed, so-called honing is performed. That is, the ridgeline where the upper surface 3 and the side surface 7 intersect is not a strict line shape due to the intersection of the two surfaces. If the ridgeline is linear, the strength of the cutting edge 11 is reduced. Therefore, R honing is applied to the region where the upper surface 3 and the side surface 7 intersect each other so that the region has a curved surface shape.

  In the insert 1 of this embodiment, the 1st honing surface 19 is formed in the area | region in which the corner cutting edge 15 is formed by the honing process. Specifically, the first honing surface 19 is formed in an area where the upper surface 3 and the side surface 7 intersect each other in a cross section passing through the corner cutting edge 15 while being orthogonal to the upper surface 3. The first honing surface 19 has a convex curve shape and is smoothly connected to the side surface 7. Further, the first honing surface 19 is smoothly connected to the rake surface 13.

  Moreover, the 2nd honing surface 21 is formed in the area | region in which the wiper cutting edge 17 is formed by the honing process. Specifically, the second honing surface 21 is formed in a region where the upper surface 3 and the side surface 7 intersect each other in a cross section passing through the wiper cutting edge 17 while being orthogonal to the upper surface 3. In a cross section perpendicular to the wiper cutting edge 17, at least a portion including the upper end continuous with the wiper cutting edge 17 on the side surface 7 has a linear shape, and the second honing surface 21 has a convex curve shape and intersects the side surface 7. ing. On the other hand, the second honing surface 21 is smoothly connected to the rake surface 13.

  In this embodiment, in the cross section orthogonal to the upper surface 3 and passing through the wiper cutting edge 17, the entire side surface 7 is linear from the upper end to the lower end. It is not limited. Since the second honing surface 21 intersects the side surface 7, at least a portion including the upper end continuous with the wiper cutting edge 17 on the side surface 7 may be a linear shape. That is, the side surface 7 including the lower end connected to the lower surface 5 has a curved shape, or the side surface 7 includes the upper end and the side surface 7 includes the lower end. May be.

In general, when honing is performed, the honing surface is formed such that the ridgeline of the cutting edge has the same convex curve shape in each region of the cutting edge. At this time, the curvature of the convex curve is set in consideration of the strength of the cutting edge and the machinability. However, when the curvature is reduced, the strength of the cutting edge is improved while the machinability is lowered. Further, when the curvature is increased, the cutting performance is improved while the strength of the cutting edge is reduced. Therefore, conventionally, it has been necessary to select which of the cutting edge strength and machinability is prioritized.

  In particular, in the case where the cutting edge has a wiper cutting edge, it is required to increase the curvature in order to improve the machinability of the wiper cutting edge, but the result is contrary to the demand to increase the strength of the corner cutting edge. .

  However, in the insert 1 of the present embodiment, the constant honing process is not simply performed on the cutting edge 11. As described above, in the region where the corner cutting edge 15 is formed, the first honing surface 19 has a convex curve shape in the region where the upper surface 3 and the side surface 7 intersect and is smoothly connected to the side surface 7. Is formed. Further, in the region where the wiper cutting edge 17 is formed, at least a portion including the upper end continuous with the wiper cutting blade 17 on the side surface 7 is a linear shape, and a convex curve shape is formed in a region where the upper surface 3 and the side surface 7 intersect. The second honing surface 21 is formed so as to intersect the side surface 7. As described above, no edge is formed between the first honing surface 19 and the side surface 7, while an edge is formed between the second honing surface 21 and the side surface 7.

Therefore, the strength of the corner cutting edge 15 can be improved by the first honing surface 19, and the machinability of the wiper cutting edge 17 can be improved by the second honing surface 21. As a result, even if the cutting edge 11 has the wiper cutting edge 17, it is possible to increase the strength of the cutting edge 11 and reduce the finished surface roughness of the work material. Incidentally, FIG. 4 is a cross-sectional view of a section through a corner cutting edge 15 as well as perpendicular to the upper surface 3, the cross section is parallel to the central axis of the through hole 9. 5 and 6 are cross-sectional views of a cross section orthogonal to the upper surface 3 and passing through the wiper cutting edge 17, and the cross section is parallel to the central axis of the through hole 9.

  Although the first honing surface 19 has a convex curve shape, specifically, for example, an arc shape, an elliptic arc shape, or a parabola shape can be used. Similarly, the second honing surface 21 has a convex curve shape. Specifically, for example, the second honing surface 21 may have an arc shape, an elliptic arc shape, or a parabolic shape. In the present embodiment, each of the first honing surface 19 and the second honing surface 21 has an arc shape.

  In the insert 1 of the present embodiment, the first honing surface 19 and the second honing surface 21 are different from each other in the configuration of the portion connected to the side surface 7, but when viewed from above, the first honing surface 19 and The honing width W of the second honing surface 21 is constant. The honing width means a distance between the outer edge and the inner edge of the first honing surface 19 and the second honing surface 21 when viewed from above. Therefore, in the cross section orthogonal to the cutting edge 11, the honing width can also be evaluated as the width in the direction orthogonal to the central axis O1 of the through hole 9 from the outer edge to the inner edge of the honing surface.

  As described above, when the honing width of the first honing surface 19 and the second honing surface 21 is constant, the thickness in the vertical direction at the portion located below the second honing surface 21 in the insert 1. Can be secured. Therefore, the edge strength of the wiper cutting edge 17 can be ensured well.

  When the honing width of the first honing surface 19 and the second honing surface 21 is constant, the distance from the corner cutting edge 15 and the wiper cutting edge 17 to the rake face 13 is constant. Therefore, chips cut by the corner cutting edge 15 and the wiper cutting edge 17 simultaneously flow to the rake face 13. Therefore, the flow of the chips cut by the corner cutting blade 15 and the flow of the chips cut by the wiper cutting blade 17 flow to the rake face 13 without interfering with each other, so that the flow of the chips becomes good.

  In the present embodiment, each of the first honing surface 19 and the second honing surface 21 has an arc shape. Thus, when the 1st honing surface 19 is circular arc shape, the intensity | strength of the 1st honing surface 19 can be raised, without enlarging the 1st honing surface 19 too much.

  Moreover, in this embodiment, as it is clear when FIG. 4 and FIG. 5 are compared, the curvature radius r2 of the second honing surface 21 having an arc shape is the curvature of the first honing surface 19 having an arc shape. It is larger than the radius r1. Further, as apparent from a comparison between FIG. 5 and FIG. 6, the radius of curvature r <b> 2 of the second honing surface 21 is set to increase as the distance from the first honing surface 19 increases. As described above, the second honing surface 21 has a portion where the radius of curvature r2 increases as the distance from the first honing surface 19 increases. As a result, the second honing surface 21 has an arc shape like the first honing surface 19 and the honing width of the first honing surface 19 and the second honing surface 21 can be made constant. Yes.

  Further, the wiper cutting edge 17 is perpendicular to the upper surface 3 and crosses the wiper cutting edge 17 so that the tangent L at the end connected to the side surface 7 of the second honing surface 21 intersects the side surface 7 at a right angle. It has a part. When the side surface 7 and the second honing surface 21 intersect at an acute angle, the cutting edge strength may be lowered while the sharpness is improved. Further, when the side surface 7 and the second honing surface 21 intersect at an obtuse angle, the cutting edge strength may be improved while the sharpness may be reduced. When the side surface 7 and the second honing surface 21 intersect at right angles, both the sharpness and the cutting edge strength can be improved.

<Cutting tools>
Next, a cutting tool 101 according to an embodiment of the present invention will be described with reference to the drawings.

  As shown in FIG. 7, the cutting tool 101 according to the present embodiment includes a holder 105 having an insert pocket 103 on the tip side, and the above-described insert pocket 103 mounted on the insert pocket 103 so that the cutting blade 11 protrudes from the tip of the holder 105. A cutting insert 1 is provided.

  The holder 105 has an elongated bar shape. One insert pocket 103 is provided on the tip side of the holder 105. The insert pocket 103 is a part to which the cutting insert 1 is attached, and is open to the front end surface of the holder 105. At this time, since the insert pocket 103 is also open to the side surface of the holder 105, the cutting insert 1 can be easily mounted. Specifically, the insert pocket 103 has a seating surface parallel to the lower surface of the holder 105 and a constraining side surface inclined with respect to the seating surface.

  The insert 1 is mounted in the insert pocket 103. The insert 1 is mounted such that the cutting edge 11 protrudes toward the tip side of the holder 105. In the present embodiment, the insert 1 is attached to the holder 105 with a fixing screw 107. That is, by inserting the fixing screw 107 into the through hole of the insert 1, inserting the tip of the fixing screw 107 into the screw hole formed in the insert pocket 103 and screwing the screw portions together, the insert 1 is inserted into the holder 105. It is attached to.

  As the holder 105, steel, cast iron, or the like can be used. In particular, it is preferable to use steel having high toughness among these members.

<Manufacturing method of cut product>
Next, the manufacturing method of the cut workpiece of one Embodiment of this invention is demonstrated using drawing.

The cut workpiece is produced by cutting the work material 201. The manufacturing method of the cut workpiece in the present embodiment includes the following steps. That is,
(1) rotating the work material 201;
(2) a step of bringing the cutting blade 11 in the cutting tool 101 represented by the above embodiment into contact with the rotating work material 201;
(3) a step of separating the cutting tool 101 from the work material 201;
It has.

  More specifically, first, as shown in FIG. 8A, the work material 201 is rotated around the axis O2, and the cutting tool 101 is relatively brought closer to the work material 201. Next, as shown in FIG. 8B, the cutting material 11 is cut by bringing the cutting edge 11 of the cutting tool 101 into contact with the work material 201. Then, as shown in FIG. 8C, the cutting tool 101 is moved away from the work material 201 relatively.

  In the present embodiment, the cutting tool 101 is moved in the X1 direction while the axis O2 is fixed and the work material 201 is rotated, thereby being brought closer to the work material 201. In FIG. 8B, the work material 201 is cut by bringing the cutting edge 11 of the cutting insert 1 into contact with the rotating work material 201. In FIG. 8C, the cutting tool 101 is moved away in the X2 direction while the work material 201 is rotated.

  In the cutting in the manufacturing method of the present embodiment, the cutting tool 101 is brought into contact with the work material 201 by moving the cutting tool 101 in each step, or the cutting tool 101 is separated from the work material 201. However, as a matter of course, it is not limited to such a form.

  For example, the work material 201 may be brought close to the cutting tool 101 in the step (1). Similarly, in the step (3), the work material 201 may be moved away from the cutting tool 101. In the case of continuing the cutting process, the state in which the workpiece 201 is rotated and the cutting blade 11 in the cutting insert 1 is brought into contact with different portions of the workpiece 201 may be repeated.

  Note that typical examples of the material of the work material 201 include carbon steel, alloy steel, stainless steel, cast iron, and non-ferrous metal.

1. Cutting insert (insert)
DESCRIPTION OF SYMBOLS 3 ... Upper surface 5 ... Lower surface 7 ... Side surface 9 ... Through-hole 11 ... Cutting blade 13 ... Rake surface 15 ... Corner cutting blade 17 ... Wiper cutting blade 19 ... First honing surface 21 ... second honing surface 101 ... cutting tool 103 ... insert pocket 105 ... holder 107 ... screw 201 ... work material

Claims (6)

A cutting insert comprising a polygonal upper surface, a lower surface, a side surface located between the upper surface and the lower surface, and a cutting edge provided on a ridge line intersecting the upper surface and the side surface,
The cutting edge has a corner cutting edge formed at a position corresponding to the corner of the upper surface, and a pair of wiper cutting edges located on both sides of the corner cutting edge,
In a cross section orthogonal to the upper surface and passing through the corner cutting edge, a region where the upper surface and the side surface intersect with each other has a convex curve shape and a first honing surface is formed so as to be smoothly connected to the side surface. And
In a cross section perpendicular to the upper surface and passing through the wiper cutting blade, at least a portion including the upper end continuous with the wiper cutting blade on the side surface is linear, and a convex curve is formed in a region where the upper surface and the side surface intersect A cutting insert having a shape and a second honing surface formed so as to intersect the side surface.   The cutting insert according to claim 1, wherein the honing width is constant when viewed from above.   2. The cutting insert according to claim 1, wherein the first honing surface has an arc shape in a cross section orthogonal to the upper surface and passing through the corner cutting edge.   In the cross section of the wiper cutting blade that is orthogonal to the upper surface and passes through the wiper cutting blade, the tangent of the end connected to the side surface of the second honing surface and the side surface intersect at a right angle. The cutting insert according to claim 1, wherein the cutting insert is characterized. A holder having an insert pocket on the tip side;
The cutting tool provided with the cutting insert as described in any one of Claims 1-4 with which the said cutting blade was mounted | worn with the said insert pocket so that it might protrude from the front-end | tip of the said holder. A step of rotating the work material;
Contacting the cutting blade of the cutting tool according to claim 5 with the rotating work material;
The manufacturing method of the cut workpiece provided with the process of separating the said cutting tool from the said workpiece.

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