JP2000254811A - Formed cutter for rough finishing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively discharge the chips even in the cutting of the complex shape and to increase a feeding speed by reducing the resistance caused by chips by alternately arranging a waveform cutting edge at first and a nick cutting edge in the next as the cutting edges. SOLUTION: A cutting blade of a form-relieved milling cutter having a convex circular arc form, comprises a shallow and fine waveform cutting edge 3, and the side surfaces of a cutting edge 2 and the waveform cutting edge are smoothly connected by the convex circular arc. The difference of the concave and convex portions of the waveform cutting edge 3 is 0.01-0.8 times of a gap to an adjacent waveform cutting edge convex peak, and a radius of the convex circular arc connected to the cutting edge 2 is 0.2-5 times of the gap. The fine chips are remained even when a length of the cutting edge by the wafeform cutting edge 3 is long, so that the chips can be easily discharged, the partial abrasion of the cutting edge can be prevented, and the cutting condition can be improved. Further the generation of defects by biting, the burr and the like caused by the waveform cutting edge 3, on the shaped form can be prevented, and the smooth finished surface can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rough finish forming milling machine used for cutting a form including a curve having a variable curvature in a machine tool.

[0002]

2. Description of the Related Art Form milling machines conform to JIS (JIS) standards.
B0172, milling terminology)
This is a milling cutter for forming a foam with a special contour, and is called a milling cutter used for forming grooves in a turbine blade or a turbine disk. Conventional cutters and roughing end mills with a corrugated cutting edge, whose purpose is to create a constant curvature or a straight plane, do not fall under the general form of milling cutters using only these blade shapes. The form milling cutter is used in the form of a second-order milling cutter in which a flank is formed by a second-order cutting process or a contour milling cutter provided with a blade along a form. Therefore, the form milling machine has the feature that the original form can be easily regenerated by re-grinding even if it is used for a long time and wears out, but on the other hand, depending on the form, the chip width becomes long and cutting Impair the nature. In particular, in the case of having a complex form including a curve in which the curvature changes, the change in the chip thickness at each part of the form is large, the cutting property is not uniform, and the chip is jammed or jammed.
There was a problem in rough cutting with large depth of cut. As an improvement measure for cutting chips and facilitating chip discharge, for example, as shown in Japanese Patent Application Laid-Open No. 8-39323, a V-shaped or U-shaped nick-shaped cutting edge may be provided on a cutting edge. Also, as illustrated in FIGS. 1 and 2, there is a type in which a corrugated cutting edge is provided in a part of the form to improve the cutting property.

[0003]

However, since the conventional nicked form milling machine described in the prior art focuses on chip separation, the gap between the corrugated cutting edge and the corrugated cutting edge is smaller than the length of the cutting edge. However, there was no effect of improving the cutting resistance because of the wide range, and it was not expected that the cutting efficiency was improved for rough cutting to improve the machining efficiency. If V-shaped or U-shaped nicks are provided carelessly, wear may concentrate on the intersection of the cutting edge and the corrugated cutting edge and the cutting accuracy may be impaired. This is problematic in the case of a form having a large curvature, especially in the case of a form inclined at a large angle with respect to the rotation axis of the milling cutter.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned background. By improving the shape and arrangement of the corrugated cutting edges of a full-form milling cutter, the present invention can be applied to a complicated form. It is an object of the present invention to provide a rough finishing full-form milling machine which can obtain a good chip discharge property and can improve a machining efficiency capable of increasing a feed rate by reducing a cutting resistance.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention achieves the above-mentioned object by providing a forma containing a curve having a varying curvature.
A rough milling cutter comprising a plurality of cutting blades forming a cutting system, wherein one of the cutting blades is provided with a corrugated cutting blade and the next blade is provided with a nick-shaped cutting blade alternately. A general-purpose milling cutter.

[0006]

By applying the present invention, the chips can be made finer and the discharge can be facilitated even when the length of the cutting edge is long due to the corrugated cutting edge. Since the cutting edge is smoothly connected with the rounding edge, the cutting edge is not worn locally, and the cutting conditions can be increased. In addition, the cutting edge caused by the corrugated cutting edge on the formed form can be obtained. No burrs, etc.
A smooth finished surface can be obtained.

Conventionally, the corrugated cutting edge is usually cut perpendicularly to the cutting edge. However, if the form is complicated as in the present invention, the corrugated cutting edge may be provided on an inclined surface. In the cutting direction, that is, a part of the corrugated cutting edge acts as a cutting edge in the rotating direction of the tool. Therefore, a failure is likely to occur in this portion, but it can be improved by applying the present invention. The corrugated cutting edge may be provided alternately with one blade and the next blade, but three or more blades may be provided at different positions.

[0008] The corrugated cutting edge is formed in a continuous wave shape of a substantially circular convex arc and a substantially concave circular arc, and the difference between the concave and convex of the corrugated cutting edge is 0.01 times to 0 times the interval between the adjacent corrugated cutting edge convex portions. The reason for setting it to be 0.8 times is that if it is less than 0.01 times, the chips cannot be sufficiently divided, and if it exceeds 0.8 times, it becomes difficult to connect the chips smoothly. The distance from the cutting edge was set to 0.01 to 0.5 times. The reason why the radius of the convex arc connected to the cutting edge is set to 0.2 to 5 times the interval is that if the interval is less than 0.2, the arc is too small to be provided and there is no point in providing a large value exceeding 5 times. If provided, the cutting edge would be too long, so the radius of the convex substantially circular arc connected to the cutting edge was 0.2 to 5 times the interval. By setting these values, the interval between the waveform cutting edges can be reduced so that a rough cutting edge can be obtained in which the waveform cutting edge of one blade and the waveform cutting edge of the next blade are shifted and overlapped. Even if the contour of the cutting edge may deviate from the overall form due to the blade, the depth of the corrugated cutting edge may be shallow within the above range, so that the irregularity of the formed form can be minimized. it can. Also in the case of the V-shaped and U-shaped cutting edges, similar operations and effects can be obtained by smoothly connecting the main cutting edges with a large arc, like the waveform cutting edges.

Next, since the form of the cutting edge of the form milling machine is various, the mode thereof will be described. First, when the form of the cutting edge is at a small angle with respect to a plane orthogonal to the rotation axis of the milling cutter, the slope of the cutting edge acts so as to cut, the chip thickness becomes thin, and the scraping phenomenon occurs. In addition, since the direction in which the waveform cutting edge is cut does not match the cutting direction, the effect is diminished and the cutting resistance increases. Therefore, when the form of the cutting edge is inclined at an angle of 30 ° or less, a straight line portion inclined at an angle smaller than the angle is provided between the substantially circular arc and the substantially circular arc so that the apex of the convex portion of the corrugated cutting edge is provided. The effect of the original waveform cutting edge can be obtained by increasing the interval.

Next, when the curvature of the form of the cutting edge is large, particularly when the adjacent cutting edge is curved by 60 degrees or more, one of the two cutting edges is located on the above-mentioned inclined surface. In addition, since the curved portion is short, the cutting edge is offset by one portion and moved in and out with one blade and the next blade. That is, the effect of the corrugated cutting edge is obtained to enhance the machinability.

Further, in the present invention, a part of the form of the cutting edge is thinned alternately for each cutting edge. In particular, when the inclined surface is at a steep angle, since the rubbing phenomenon is large on the side surface, it can be alleviated by thinning a part of the cutting edge. If the diameter difference between the cutting blades is large depending on the position of the form, the interval between the first blade and the next blade is reduced at the small diameter portion, and the sharpness is reduced. Further, even at the outer peripheral portion, it may be thinned out due to the twist angle or the form. Further, when a coating is applied to the form milling cutter, the coating may be made of a transition metal of Group 4a, 5a, or 6a of the periodic table, a low melting point metal, a rare earth metal, or a carbide, nitride, or oxide of Al. , Boride, hard boron nitride, hard carbon, and one or more hard films selected from the group consisting of solid solutions and mixtures thereof and / or one lubricating film such as MoS Alternatively, coating with a multilayer of two or more layers at a thickness of 0.2 to 20 μ can improve abrasion resistance and further prolong the life. In addition, a high-speed steel, an ultra-fine-grain cemented carbide, a TiCN-based cermet, or the like can be used for the form milling machine. In particular, a molten high-speed steel and a powdered high-speed steel are excellent in terms of workability. Hereinafter, the present invention will be described with reference to the drawings showing the embodiments.

[0012]

FIG. 3 and FIG. 4 show an embodiment of the present invention, which is a second milling cutter having a convex arc-shaped form. This cutting edge is provided with a shallow and fine corrugated cutting edge as shown in FIG. 4, and the cutting edge and the side surface of the corrugated cutting edge are smoothly connected by a convex arc. In the conventional nicked type, although the influence is small at the top of the convex arc, since the cutting is performed with the contact between the cutting edge and the nick rising at both end portions, the wear of this portion tends to be severe. According to the present invention, local wear frequently occurring in the conventional product can be reduced, cutting accuracy can be maintained for a long time, and cutting conditions can be sped up.

FIG. 5 shows a milling cutter having a maximum diameter of 118 mm, a cutting edge width of 20 mm, and eight blades. As shown in an enlarged view in FIG. 6, the form of the overall shape is composed of a convex arc portion forming the outermost peripheral portion, a steep slope connected thereto, and a concave arc portion forming a small diameter portion. The corrugated cutting edges are provided at intervals of 0.2 mm in depth and 1 to 1.5 mm in width along the cutting edges. Here, the details of the corrugated cutting edge are as shown in FIGS. That is, FIG. 7 shows a wave-shaped cutting edge having a continuous wavy shape of a substantially convex arc and a substantially concave arc provided at the outermost convex arc portion, and FIG. A small angle linear portion is provided. FIG. 9 shows a bent portion which transitions from the outermost periphery to a steep slope portion. Since the curvature is large, the cutting edge is moved in and out to replace the corrugated cutting edge.

Using this, a flat plate of stainless steel SUS410 was formed and cut into the above-mentioned form. The cutting specifications are a cut of 15 mm in the axial direction of the tool, a cut of 10 mm in the radial direction of the tool, a rotational speed of the tool of 65 revolutions / min, and a feed speed of 65 mm / min. In the example of the present invention, one workpiece was completed in 45 minutes. For comparison, when the cutter described in the prior art for processing the same form was used, the number of rotations could not be increased, so that two cutters per workpiece were used.
It took 50 minutes.

FIG. 10 shows another embodiment of the present invention.
The dimensions are similar to those in Fig. 1 above, but they are not the second-cut blade type.
The flank has a contoured blade shape ground, and a cutting edge is also provided on the side surface from the outer periphery toward the axis. The side blades are thinned out from the vicinity of the outer periphery for each blade. Since the distance between the cutting edges becomes narrower as approaching the partial axis, cutting performance can be enhanced by thinning.

[0016]

As described above, according to the present invention, by improving the shape and arrangement of the corrugated cutting edge, it is possible to obtain a good chip discharge property, and to reduce the cutting resistance to increase the feed rate. The result is an improved form milling cutter for rough cutting.

[Brief description of the drawings]

FIG. 1 shows a front view of an example of a conventional product.

FIG. 2 shows a side view of FIG. 1;

FIG. 3 shows a front view of an embodiment of the present invention.

FIG. 4 is an enlarged view of a main part of FIG. 3;

FIG. 5 shows a front view of another embodiment of the present invention.

FIG. 6 shows an overall form formed according to FIG. 5;

FIG. 7 shows the configuration of a part of the corrugated cutting edge of FIG. 5;

FIG. 8 shows the configuration of another part of the corrugated cutting edge of FIG. 5;

FIG. 9 shows the configuration of still another part of the corrugated cutting edge of FIG. 5;

FIG. 10 shows a front view of another embodiment of the present invention.

FIG. 11 shows a front view of another embodiment of the present invention.

[Explanation of symbols]

 1 Body 2 Cutting Edge 3 Wave Cutting Edge 4 Depth of Wave Cutting Edge 5 Spacing between Wave Cutting Edges 6 Roundness Connecting Wave Cutting Edge and Cutting Edge 7 Overall Form α Inclination Angle of Overall Form θ Angle of inclination of the substantially straight part provided on the waveform cutting edge

Claims (5)

[Claims] 1. A form milling machine having a plurality of cutting edges forming a form including a curve of varying curvature.
A full-form milling machine for rough finishing characterized in that one of the cutting edges is provided with a corrugated cutting edge and the next is provided with alternating nick-shaped cutting edges. 2. The rough finishing milling cutter according to claim 1, wherein the corrugated cutting edge has a continuous wavy shape of a substantially circular arc of a convex and a substantially circular arc of a concave, and the difference between the irregularities of the corrugated cutting edge is adjacent. The feature is that the radius of the convex substantially circular arc connected to the cutting edge is provided at a value of 0.2 to 5 times the interval between the peaks of the corrugated cutting edge and / or 0.2 to 5 times the interval. A rough milling cutter for rough finishing. 3. The rough milling cutter according to claim 1, wherein the nick-shaped cutting edge is provided in a V-shape and / or a U-shape, and is connected to the main cutting edge by a large arc. A rough milling cutter for rough finishing. 4. The rough finishing milling cutter according to claim 1, wherein the form of the cutting edge is inclined at an angle of not more than 30 degrees with respect to a plane perpendicular to the rotation axis of the milling machine. A general finishing mill for rough finishing, wherein a straight portion inclined at an angle smaller than the angle is provided between a substantially arc of a convex and a substantially arc of a concave. 5. A rough finishing milling cutter according to claim 1, wherein the form of the cutting edge has a large curvature, and when the adjacent cutting edge is bent by 60 degrees or more,
A general-purpose mill for rough finishing characterized in that the cutting edge form is moved in and out of the first and second blades.