JP2005052911A - Throwaway tip - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a throwaway tip which is easy to manufacture, does not cause an increase in cutting resistance, and improves finished roughness of a worked surface of a workpiece. <P>SOLUTION: A cutting edge ridge 15 to be an intersecting ridge of a rake face 11 and a flank 13 of an approximately polygonal planar tip body 10 has an approximately arcuate cutting edge ridge 16 located at a nose 14 of the rake face 11 and a pair of approximately linear cutting edge ridges 17 and 17 located on sides of the rake face 11. In the top view from a direction opposite to the rake face 11, the ridge 16 is retreated inwardly toward the tip body 10 from an ideal arc 30 having the ridges 17 and 17 as tangents, and the ridge 16 and the ridges 17 and 17 are smoothly connected. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a throw-away tip (hereinafter referred to as a tip) that is detachably attached to a tool body of a throw-away type cutting tool, and in particular, an abbreviated position located in a nose portion of a substantially polygonal flat plate-shaped tip body. The present invention relates to a tip for performing a turning process such as an outer diameter process mainly using an arcuate cutting edge ridge line.
[0002]
[Prior art]
As this type of chip, as disclosed in Patent Document 1, a cutting edge ridge line that is a cross ridge line part of a rake face and a flank face of a chip body having a substantially polygonal flat plate shape is a nose part of the rake face. A substantially arcuate cutting edge ridgeline located at the edge of the rake face and a substantially linear cutting edge ridgeline located at the side of the rake face. The substantially arcuate cutting edge ridgeline and the substantially linear cutting edge ridgeline in the cutting edge ridgeline. What has formed the curved recessed part in the connection part is known.
When such a tip is mounted on the tool body, the cutting edge ridge line of the portion corresponding to the curved recess is retreated to the inner side of the tip body in a top view as viewed from the direction facing the rake face. Therefore, the projected curvature radius (apparent curvature radius) in plan view at the cutting edge ridgeline of the part corresponding to the curved concave portion is substantially larger than the design value of the standard product, and the work surface of the workpiece is It is possible to improve the finished surface roughness.
[0003]
[Patent Document 1]
Japanese Patent Laid-Open No. 2000-288803
[Problems to be solved by the invention]
By the way, recently, a chip made of a so-called cBN sintered body in which a part of a chip body including at least a cutting edge ridge line acting on cutting is formed of a high-hardness cBN (cubic boron nitride) sintered body seems to be frequently used. It is becoming.
However, such a chip made of a cBN sintered body is high in hardness, but has poor toughness and weakness compared to cemented carbide and the like, and tends to cause chipping and chipping. If you try to form a curved recess as described in the section of the cutting edge ridge line at the connection point between the substantially arcuate cutting edge ridge line and the substantially linear cutting edge ridge line, chipping and chipping are apt to occur, making it difficult to manufacture. Therefore, the current situation is that it cannot be an effective solution for improving the roughness of the finished surface.
[0005]
Further, in Patent Document 1, the connection portion between the substantially arcuate cutting edge ridge line and the substantially linear cutting edge ridge line in the cutting edge ridge line is intentionally projected with a large radius in a top view as viewed from the direction facing the rake face. Although a chip with R is also mentioned, in the case of such a chip, since the above-mentioned curved concave portion does not exist, even if it is a chip made of a cBN sintered body, its manufacture is not difficult. There is a problem that the contact area of the cutting edge ridge line with the workpiece becomes too large, leading to an increase in cutting resistance.
[0006]
The present invention has been made in view of the above problems, and provides a chip that is easy to manufacture and that can increase the finished surface roughness of the work surface of the workpiece without increasing the cutting resistance. The purpose is that.
[0007]
[Means for Solving the Problems]
In order to solve the above problems and achieve such an object, the present invention provides a cutting edge ridge line which is a cross ridge line portion between a rake face and a flank face of a chip body having a substantially polygonal flat plate shape. In a chip having a substantially arcuate cutting edge ridge line located at the nose portion of the rake face and a substantially linear cutting edge ridge line located at the side part of the rake face, the chip is viewed from the direction facing the rake face. When viewed from above, the substantially arcuate cutting edge ridge line is retracted inward of the chip body from an ideal arc with the substantially linear cutting edge ridgeline as a tangent line. The substantially straight cutting edge ridge line is smoothly connected.
[0008]
According to the present invention having such a configuration, since the substantially arcuate cutting edge ridge line is retracted as described above, the contact area of the cutting edge ridge line with the workpiece is reduced, and the cutting resistance is increased. Since the substantially arcuate cutting edge ridge line and the substantially linear cutting edge ridge line can be smoothly connected, the work surface of the workpiece machined by the cutting edge ridge line of such a tip can be suppressed. Finished surface roughness can be improved. Moreover, even if the chip according to the present invention is a chip made of a cBN sintered body, it is not necessary to form a curved concave portion as in the prior art, so that it is not difficult to manufacture the chip.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the accompanying drawings.
A chip body 10 of a chip according to an embodiment of the present invention has a substantially rhomboid plate shape (substantially polygonal plate shape) made of a hard material such as cemented carbide, as shown in FIG. The upper surface, which is one substantially rhombus surface (substantially polygonal surface), of the main body 10 is a rake surface 11, and the lower surface, which is the other approximately rhombus surface (substantially polygonal surface), of the chip body 10 is a seating surface 12. A side surface of the chip body 10 connecting the rake surface 11 and the seating surface 12 is a flank 13.
[0010]
As shown in FIG. 2, in the rake face 11, the vicinity of one nose portion 14 having an apex angle θ set to an acute angle of, for example, 80 ° when viewed from the top facing the rake face 11 is a flank 13. The intersecting ridge line portion formed by intersecting with the cutting edge is the cutting edge ridge line 15 formed on the chip body 10.
The cutting edge ridge line 15 is located at one nose portion 14 of the rake face 11 and is connected to a substantially arcuate cutting edge ridge line 16 having a substantially arc shape, and both ends of the substantially arcuate cutting edge ridge line 16, A pair of substantially straight cutting edge ridge lines 17, 17 which are located on the side of the rake face 11 and form a substantially straight line shape.
[0011]
Here, in a top view as viewed from the direction facing the rake face 11, the pair of substantially linear cutting edge ridge lines 17, 17 are tangent to the pair of substantially linear cutting edge ridge lines 17, 17. Consider an ideal arc 30 connected tangentially.
In the present embodiment, when comparing the ideal arc 30 and the substantially arcuate cutting edge ridge line connected to the pair of substantially linear cutting edge ridge lines 17 and 17 like the ideal arc 30, first, The radius R1 of the virtual circle S1 having the arcuate cutting edge ridge line 16 as an arc (the radius of curvature of the substantially arcuate cutting edge ridgeline 16) and the radius R2 of the virtual circle S2 having the arcuate arc 30 as the arc (the ideal arc 30) (Radius of curvature) is set to be substantially the same.
[0012]
However, the center P1 of the virtual circle S1 whose arc is the substantially arcuate cutting edge ridge line 16 is retreated toward the inner side of the chip body 10 from the center P2 of the virtual circle S2 whose arc is the ideal arc 30. Accordingly, the substantially arcuate cutting edge ridge line 16 itself is also retracted from the ideal arc S toward the inward side of the chip body 10.
The distance t between the center P1 of the virtual circle S1 whose arc is the substantially arcuate cutting edge ridge line 16 and the center P2 of the virtual circle S2 whose arc is the ideal arc 30 is, for example, 0.005 mm to The range is set to 0.020 mm.
[0013]
Thus, since the substantially arcuate cutting edge ridge line 16 is retreated to the inner side of the chip body 10 from the ideal arc 30 having the pair of substantially linear cutting edge ridgelines 17 and 17 as a tangent, The connecting portions 16A and 16A, which are both ends of the arcuate cutting edge ridge line 16 connected to the pair of substantially linear cutting edge ridge lines 17 and 17, are substantially arcuate (curved) or substantially linear and substantially arcuate. The cutting edge ridge line 16 and the pair of substantially linear cutting edge ridge lines 17 and 17 are smoothly connected to each other.
[0014]
In addition, a cutting edge chip obtained by integrally sintering a hard sintered body 18 such as cemented carbide and a cBN sintered body 19 in a layered manner with respect to the recess formed in the chip body 10 is a portion of the cBN sintered body 19. Is joined to the rake face 11 side by brazing or the like, so that the vicinity of one nose portion 14 on the rake face 11 of the chip body 10 is constituted by this cutting edge tip. Is formed on the cBN sintered body 19 in the cutting edge tip.
For this reason, the chip according to the present embodiment is a chip made of a so-called cBN sintered body in which at least a part of the chip body 10 including the cutting edge ridge line 15 is configured by the cBN sintered body 19 having high hardness.
[0015]
The cutting edge ridge line 15 formed of the cBN sintered body 19 has a cross-sectional ridge line portion between the rake face 11 and the flank face 13 as shown in FIG. 3 as viewed in a cross section orthogonal to the cutting edge ridge line 15. By performing chamfer honing that is chamfered in a straight line, a chamfered surface 20 having a substantially straight cross section that intersects the rake face 11 and the flank face 13 at an obtuse angle is formed.
Further, in this cutting edge ridge line 15, as shown in FIG. 3 as seen in a cross section orthogonal to the cutting edge ridge line 15, the cross ridge line portion between the chamfered surface 20 and the flank surface 13 by chamfer honing has a substantially curved cross section. The chamfered round honing is performed to form a chamfered surface 21 having a substantially curved cross section that intersects the chamfered surface 20 and the flank 13 by chamfer honing.
[0016]
The tip according to the present embodiment having such a configuration causes one nose portion 14 of the rake face 11 of the tip body 10 to protrude from the tip of the tool body, and a pair of substantially linear cutting edge ridge lines at the cutting edge ridge line 15. 17 and 17, positive side clearance angle (inclination angle of one substantially linear cutting edge ridge line 17 with respect to the direction parallel to the axis of the workpiece, for example, 5 °) and positive front clearance angle (the other substantially linear shape) The cutting edge ridge line 15 is attached to the tool body so as to give an inclination angle with respect to the direction perpendicular to the axis of the workpiece (for example, 5 °). Using the substantially arcuate cutting edge ridge line 16 and the substantially linear cutting edge ridgelines 17 and 17), a turning process such as an outer diameter process is performed on the workpiece rotated around the axis.
[0017]
Here, the tip according to the present embodiment shown in FIG. 1 is of a negative type in which the flank 13 connected to the cutting edge ridge line 15 is substantially orthogonal to the seating surface 12 and the rake face 11 of the tip body 10. However, even such a negative type tip is attached to the tool body so as to be inclined with respect to the reference plane of the tool body, the flank 13 connected to the cutting edge ridge line 15 has a predetermined surface. A relief angle is given. If the flank 13 that continues to the cutting edge ridge line 15 is a positive type tip that inclines toward the inner side of the tip body 10 as it goes toward the seating surface 12 side of the tip body 10, of course, A predetermined clearance angle is given to the flank 13 connected to the cutting edge ridge line 15.
The point is that the insert is mounted on the tool body such that a predetermined clearance angle is given to the clearance surface 13 connected to the cutting edge ridge line 15.
[0018]
In the chip according to the present embodiment as described above, first, the substantially arcuate cutting edge ridge line 16 is retreated toward the inner side of the chip body 10 with respect to the ideal arc 30, so that the cutting edge ridge line 15 is formed. It is possible to reduce the area in contact with the workpiece, and the cutting resistance is not increased unnecessarily.
[0019]
Since the substantially arcuate cutting edge ridge line 16 retracted with respect to the ideal arc 30 and the pair of substantially linear cutting edge ridgelines 17 and 17 are smoothly connected by the connecting portions 16A and 16A, In a state in which the tip according to the embodiment is mounted on the tool body, the projected curvature radius in the plan view in the vicinity of the connection portions 16A and 16A of the cutting edge ridge line 15 in the plan view viewed from the direction facing the reference plane of the tool body. It becomes substantially larger than the design value of the standard product.
Accordingly, when the work surface of the workpiece is cut by such a cutting edge ridge line 15, the finish is compared with the case where the substantially arcuate cutting edge ridge line 16 has a pair of substantially linear cutting edge ridge lines 17 and 17 as tangent lines. Surface roughness can be improved.
[0020]
Furthermore, although the chip according to the present embodiment is a chip made of a cBN sintered body, it is possible to improve the finished surface roughness of the work surface of the workpiece without forming the curved concave portion as described above. Therefore, it is not difficult to manufacture.
[0021]
In the present embodiment, the case where one nose portion 14 of the rake face 11 of the chip body 10 has an apex angle θ of 80 ° in a top view is not limited to this. For example, The nose portion 14 may have an apex angle θ of 35 °, 55 °, or 90 ° when viewed from above.
[0022]
【The invention's effect】
As described above, according to the present invention, the contact area of the cutting edge ridge line with respect to the workpiece is reduced by reducing the substantially arcuate cutting edge ridge line with respect to the ideal arc, and the cutting resistance is increased. The finished surface of the work surface of the workpiece machined by the cutting edge ridge line of such a chip by being able to suppress and smoothly connecting the substantially arcuate cutting edge ridge line and the substantially straight cutting edge ridge line. Roughness can be improved. Moreover, even when the chip according to the present invention is a chip made of a cBN sintered body, it is not necessary to form a curved concave portion as in the conventional case, so that it is not difficult to manufacture the chip.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a chip according to an embodiment of the present invention.
FIG. 2 is an enlarged top view of a main part showing a chip according to an embodiment of the present invention.
FIG. 3 is an enlarged cross-sectional view of a main part perpendicular to a cutting edge ridge line of a chip according to an embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Tip main body 11 Rake face 13 Flank 14 Nose part 15 Cutting edge ridge line 16 Substantially circular cutting edge ridge line 16A Connection part 17 to a substantially linear cutting edge ridge line in a substantially circular arc cutting edge ridge line 17 General linear cutting edge ridge line 19 cBN Sintered body 30 Ideal arc

Claims (1)

The cutting edge ridge line, which is the intersecting ridge line part of the rake face and flank face of the chip body having a substantially polygonal flat plate shape, is a substantially arcuate cutting edge ridge line located at the nose part of the rake face, and the side part of the rake face. In the throw-away tip having a substantially straight cutting edge ridge located at
In top view as seen from the direction facing the rake face,
The substantially arcuate cutting edge ridge line is retracted inward of the chip body from an ideal arc having the substantially linear cutting edge ridgeline as a tangent line. A throw-away tip that is smoothly connected to the edge of the blade.

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