JPH0737515U - Throw-away tip - Google Patents

Abstract

(57) [Summary] [Purpose] To improve the fracture resistance of the secondary cutting edge of the corner. [Structure] The corner portion of the upper surface 3b of the throw-away tip 10 having a rectangular plate shape, which is located between the main cutting edges 4 and 4, is an arc-shaped ridge line, and the central portion thereof is cut into a straight line to form a sub cutting edge 11. The arc-shaped ridgelines on both sides of the arc-shaped cutting edges 12, 12
And Seating surface 3a from the side of the corner to the arc-shaped ridgeline
The curved side surface 13 has an arcuate cross-section up to and is cut out in a triangular shape from the auxiliary cutting edge 11 to the middle of the seating surface to form a cut surface 14. Secondary cutting edge 11 on upper surface 3b and arcuate cutting edges 1 on both sides thereof
Honing consisting of the inclined surface 15 is applied to the portions 2 and 12.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a throw-away tip suitable for use in a cutting tool such as a face mill.

[0002]

[Prior art]

 Conventionally, as an example of this type of cutting tool, there is a face mill as shown in FIG. In this face milling cutter, grooves 2 for insert of a throw-away tip are provided on the outer periphery of the tip of a tool body 1 in a circumferentially dispersed manner. A mounting surface 2a is formed in each groove 2 and faces forward in the rotational direction of the tool body 1. The seating surface of the throw-away tip 3 is seated and positioned on the mounting surface 2a, and a wedge member (not shown) is formed. Alternatively, the throw-away tip 3 is fixed by screwing a screw into a screw hole formed in the chip 3.

The throw-away tip 3 has, for example, a rectangular plate shape as shown in FIGS. 5 (A) and 5 (B), and has a surface facing the seating surface 3 a seated on the mounting surface 2 a of the tool body 1. As the upper surface 3b, planar side surfaces 3c inclined outward from the seating surface 3a toward the upper surface 3b are formed on the four circumferences between the seating surfaces 3a and 3b. The ridgeline forming each side of the upper surface 3b constitutes the main cutting edge 4, and the corner portion between the adjacent main cutting edges 4 is cut out to form the sub cutting edge 5 to form the finishing blade. The part is cut out from the sub cutting edge 5 of the upper surface 3b to the seating surface 3a, and a rectangular corner surface 6 is provided. Further, as shown in FIG. 6, a chamfer 7 (constituting a cutting edge) is applied to a corner portion where the auxiliary cutting edge 5 and the main cutting edge 4 intersect, and this chamfer 7 portion extends from the upper surface 3b to the seating surface 3a. The chamfered surface 8 having a rectangular shape is formed by extending. With such a throw-away tip 3 attached to the tool main body 1 shown in FIG. 4, the auxiliary cutting edge 5 projects toward the tip side of the tool main body 1, and the main cutting edge 4 adjacent to the auxiliary cutting edge 5 inclines to the outside thereof. Will be located.

[0004]

[Problems to be solved by the device]

 However, when the work material is laterally feed cut, for example, by the milling cutter having such a configuration, as shown in FIG. 6, the corner a forming the intersection of the auxiliary cutting edge 5 and the chamfer 7 and the chamfer 7 and the main cutting 7 are formed. There is a problem that the corner portion b that forms a boundary with the blade 4 is easily chipped, which adversely affects the machining accuracy of the work material. Further, since the corners a, b and the like are easily damaged, it is necessary to frequently change the corners during cutting, which complicates the attachment / detachment work and has a drawback that the throw-away tip 3 has a short life.

In view of the above problems, an object of the present invention is to provide a throw-away tip in which a cutting edge at a corner portion, an intersection thereof, and the like are less likely to be chipped.

[0006]

[Means for Solving the Problems]

 The throw-away tip according to the present invention is a throw-away tip in which the ridge line forming each side of the surface facing the seating surface is the main cutting edge, and the ridge line of the corner between the adjacent main cutting edges is the sub cutting edge. In, the corner of the surface facing the seating surface forms an arcuate ridgeline and the center part is cut linearly to form a sub-cutting edge, and the arcuate ridgeline between this sub-cutting edge and the main cutting edge is It is characterized by being an arc-shaped cutting edge.

Further, it is characterized in that the side surface of the corner portion forms a curved side surface having an arcuate cross section and is cut in a substantially triangular shape from the auxiliary cutting edge toward the seating surface direction. Further, it is characterized in that the auxiliary cutting edge and the arcuate cutting edges on both sides thereof are provided with honing on the surface facing the seating surface.

[0008]

[Action]

 Therefore, at the corner of the throw-away tip, the connection from the main cutting edge to the arcuate cutting edge is smooth, and the connection from the arcuate cutting edge to the sub-cutting edge has a large obtuse angle and a curved line. Due to the structure in which and are connected, most of the corners are not formed and are less likely to be lost. Moreover, since the side surface of the connecting portion between the arcuate cutting edge and the main cutting edge is formed by the curved side surface, the strength is higher than that of the side surface having a prismatic shape. Also, the honing results in a higher cutting edge strength.

[0009]

【Example】

 A preferred embodiment of the present invention will be described below with reference to FIGS. 1 to 3, but the same parts or members as those of the above-described conventional art will be designated by the same reference numerals and the description thereof will be omitted. 1A is a plan view of a throw-away tip according to an embodiment, FIG. 1B is a side view of the same, FIG. 2 is an enlarged plan view of a corner portion of FIG. 1, and FIG. 3 is a sectional view taken along line XX of FIG. is there. In the throw-away tip 10 shown in FIGS. 1 and 2, each corner portion between the adjacent main cutting edges 4 and 4 on the upper surface 3b is formed into an arc-shaped ridge line, and the central portion thereof is cut straight. And constitutes the sub cutting edge 11. The arc-shaped ridge lines connected to the main cutting edges 4 on both sides of the sub-cutting edge 11 respectively form arc-shaped cutting edges 12, 12.

Further, the side surface of the corner portion of the throw-away tip 10 is formed as a curved side surface 13 having an arcuate cross section which extends obliquely from the arcuate ridgeline including the arcuate cutting edges 12, 12 of the upper surface 3b to the seating surface 3a. In addition, the central portion near the upper surface 3b is cut by a substantially triangular flat cutting surface 14 extending from the auxiliary cutting edge 11 to a midpoint in the seating surface 3a direction of the curved side surface 13 (Fig. 1 (B) and See FIG. 2). In addition, the regions of the arcuate cutting edges 12, 12 and the sub-cutting edge 11 between them at each corner of the upper surface 3b are subjected to honing, so that the arcuate cutting edges 12, 12 and the sub-cutting edge 11 are attached to the upper surface 3b. The honing inclined surface 15 (see FIG. 3) and the curved side surface 13 and the cut surface 14 are formed at the ridge line portion intersecting with each other.

Since the throw-away tip 10 according to the present embodiment is configured as described above, it will be mounted on the tool body 1 of the face milling cutter as shown in FIG. 4, for example, for cutting. In the throw-away tip 10 according to the present embodiment, from the main cutting edge 4 to the arcuate cutting edge 12 at each corner, the cutting edge is smoothly connected from a straight line to an arcuate curve, and then from this arcuate cutting edge 12 to the sub-cutting edge. Since the blade 11 has a large obtuse angle and one of the cutting edges 12 has a circular arc shape, it is smoothly taken over from an arc-shaped curve to a straight line, and a corner portion that is apt to be damaged is hardly formed. Moreover, on the side surface of the corner portion of the chip 10, the crossing ridge portion between the cut surface 14 and the curved side surface 13 is arranged in a direction that gradually approaches a substantially triangular shape from the upper surface 3b toward the seating surface 3a. As for each connecting portion between the sub cutting edge 11 and the two arcuate cutting edges 12, the curved side surface 13 is thicker than the prismatic portion in the side surface direction, and the strength thereof is increased. Moreover, since the secondary cutting edge 11 at the corner and the arcuate cutting edges 12 and 12 connected to both sides thereof are subjected to honing, the strength of the cutting edge of each of the cutting edges 11 and 12 is also improved by this. By strengthening, it becomes more difficult to cause a defect in the sub cutting edge portion.

As described above, according to this embodiment, almost no corners are formed at the connecting portions of the sub cutting edge 11 at the corner and the arcuate cutting edges 12, 12 on both sides thereof, and the sub cutting edge 11 is formed. Since the side surface of the connecting portion between the arc-shaped cutting edge 12 and the arc-shaped cutting edge 12 is formed by the thicker curved side surface 13, the strength of the sub-cutting edge 11 portion is extremely high, and a defect is less likely to occur. Therefore, there is an advantage that the life of the throw-away tip 10 can be extended. Moreover, by providing honing to the sub cutting edge 11 and the arcuate cutting edges 12 and 12, the cutting edge strength is further increased.

Here, an example of the shape and size of the throw-away tip 10 according to the present embodiment is as follows, but it is needless to say that other size and shape can be set without being limited to this. Nor. The throw-away tip 10 has a substantially square plate shape, and one side of the upper surface 3b is about 12. In the case of 70 mm, the width of the sub cutting edge 11 in plan view is about 1.6 mm, the angle of inclination of the cut surface 14 in the side view with respect to the vertical direction is about 25 degrees, and the angle of inclination of the curved side surface 13 with respect to the vertical direction is 20 mm. Degree, the radius of the circular arc including the pair of arcuate cutting edges 12, 12 is about 2.4 mm, the width of the honing inclined surface in plan view is about 0.18 mm, and the inclination angle with respect to the upper surface 3b is about 25 degrees. .

In the above numerical example, the length (chord) of the sub cutting edge 11 is set to 1.6 mm with respect to the radius of the arc-shaped ridgeline of the corner portion of 2.4 mm, but the ratio of the two may be other appropriate. Needless to say, it can be set to the size of. Further, the shape of the throw-away tip 10 is not limited to a rectangle as in the embodiment, and may be a triangle or a polygon. In the above-mentioned embodiment, the throw-away tip for mounting the face milling cutter has been described, but the throw-away tip according to the present invention can be attached to other appropriate cutting tools without being limited to this embodiment.

[0015]

[Effect of device]

 As described above, in the throw-away tip according to the present invention, the corner portion forms an arcuate ridge line and the central portion is linearly cut to form a sub-cutting edge, and the sub-cutting edge and the main cutting edge are separated from each other. Since the arcuate ridgeline between them is an arcuate cutting edge, almost no corners are formed at the connecting part of the sub-cutting edge and the arcuate cutting edges on both sides of it, and the strength of the sub-cutting edge is extremely high, and there is no damage. Unlikely to occur. Therefore, there is an advantage that the life of the throw-away tip can be extended. In addition, the side surface of the corner portion is a curved side surface with an arcuate cross section, and is cut into a substantially triangular shape from the auxiliary cutting edge toward the seating surface, so the side surface of the connecting portion between the auxiliary cutting edge and the arcuate cutting edge. Is formed by a thicker curved side surface, so that the cutting edge strength is further increased. Moreover, by providing honing to the sub cutting edge and the arcuate cutting edge, the cutting edge strength is further increased.

[Brief description of drawings]

FIG. 1A is a plan view of a throw-away tip according to an embodiment of the present invention, and FIG. 1B is a side view of the same.

FIG. 2 is an enlarged plan view of a corner portion of FIG.

3 is a cross-sectional view taken along line XX of FIG.

FIG. 4 is a cross-sectional view of a tool body showing a general state in which a throw-away tip is attached to a front milling cutter.

5A is a plan view of a conventional throw-away tip, and FIG. 5B is a side view of the same.

FIG. 6 is an enlarged plan view of a corner portion of FIG.

[Explanation of symbols]

 4 Main cutting edge 3a Seating surface 10 Throwaway tip 11 Sub cutting edge 12 Arcuate cutting edge 13 Curved side surface 14 Cutting surface

Claims (3)

[Scope of utility model registration request] 1. A throw-away tip in which a ridge line forming each side of a surface facing a seating surface is a main cutting edge, and a ridge line of a corner portion between adjacent main cutting edges is a sub cutting edge. The corner portion of the surface facing the surface forms an arc-shaped ridgeline and the central portion is cut linearly to form a sub-cutting edge,
A throw-away tip, wherein the arcuate ridgeline between the sub cutting edge and the main cutting edge is an arcuate cutting edge. 2. The side surface of the corner portion is a curved side surface having an arcuate cross section, and is cut in a substantially triangular shape from the auxiliary cutting edge toward the seating surface direction. Throw-away tip. 3. The throw-away tip according to claim 1, wherein a honing is provided on a portion of the sub-cutting edge and the arc-shaped cutting edges on both sides of the sub-cutting edge of the surface facing the seating surface.