JPH0929530A - Roughing end mill - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent chipping in a cutting blade in a heavy cutting by specifying the rake angle of a corrugated outer circumferential blade, and achieving the honing on the flank along the corrugated contour. SOLUTION: A tool body 1 is made of the powder high-speed tool steel of high hardness type, and a plurality of twisted corrugated outer circumferential blades 2 are provided on its outer circumference. The rake angle of the corrugated outer circumferential blade 2 is 8-20 deg., and the honing is achieved by the brush honing method on the flank along the projected contour of the corrugated cutting blade with the width of 0.02-0.03mm. The position necessary for the honing is only the part related to the cutting, and the feed per blade of the roughing end mill is at most about 2-3% of the diameter, and the part of the length of 5% of the blade diameter may be honed in the radial direction from the top of the corrugated cutting blade.

Description

Detailed Description of the Invention

[0001]

2. Description of the Related Art In a solid roughing end mill, a cutting edge is usually formed in a wavy shape having irregularities as shown in FIG. 1, and when used, cutting is started by starting from one point on the convex portion of the wavy cutting edge 3. By concentrating the force, the cutting resistance at the time of biting is reduced, and at the same time, the concave portions between the wavy cutting edges 3 serve as chip breakers to facilitate the removal of chips and, as the name implies, enable rough cutting. .

[0002] As an example, there is a roughing end mill (hereinafter referred to as a conventional product) of No. 4-128115, which has different amounts on a rake face side and a flank face side after grinding a cutting edge. Horning
Then, it is coated with a hard wear resistant material.

[0003]

However, the roughing end mill has a structure in which only the vicinity of the apex of the wavy cutting edge is involved in cutting, and the cutting force is concentrated near the apex, resulting in microscopic impact fracture. It has been a cause for causing a limitation and limits the tool material for producing the same. In the conventional product, this is improved and the cutting edge is reinforced by honing and hard film coating. Further, it is extremely difficult to perform uniform honing on the entire surface of the wavy cutting edge itself, and there is a problem in that unevenness in the finished product is likely to occur and variation in performance is caused.

[0004]

SUMMARY OF THE INVENTION The present invention has been made based on the above-mentioned background, and in particular, even if heavy cutting with a large cutting load is performed, the cutting property and the cutting edge strength are maintained and chipping or chipping occurs. It is an object of the present invention to provide a roughing end mill that suppresses the above-mentioned problems and has little performance variation and is excellent for rough cutting.

[0005]

In order to achieve the above object, the present invention provides a roughing end mill having a plurality of twisted corrugated outer peripheral cutting edges on the outer periphery of a tool body,
The rake angle of the corrugated outer peripheral blade is 8 to 20 °, and horning having a width of 0.02 to 0.05 mm is provided on the flank along the corrugated contour. In addition, honing is performed along the wavy contour from the apex of the wavy outer peripheral edge in the tool radial direction at least 0.05 times the blade diameter.

[0006]

By applying the present invention, it is possible to maintain a sufficient cutting edge angle without damaging the machinability even if honing is performed on the flank, and the effect of honing causes chipping during cutting. It has become possible to cut for a long time without causing chipping or chipping. Also, as the honing method, if the brush honing method is adopted, it is possible to perform honing while keeping the cutting edge sharp, and since only the vicinity of the top of the wavy cutting edge is honed, Since it is not necessary to apply an excessive honing force, a roughing end mill with good performance can be obtained uniformly and in a short time.

Here, the reason why the rake angle is limited to 8 ° to 20 ° will be described. As described above, in the roughing end mill, since the top of the wavy cutting edge intermittently participates in the cutting, the cutting force acts intensively. The rake angle is smaller than that of a general end mill so that the cutting edge does not chip or damage against the cutting force, and is usually set to about 8 ° or less. In such a configuration,
When applied, the cutting edge angle at the top of the wavy cutting edge is 82
Although the cutting edge strength is excellent when it is at least 0 °, the sharpness is poor. As a means for improving this, the rake angle is increased to 8 ° or more. However, if the rake angle exceeds 20 °, the cutting edge angle becomes 70 ° or less, so that the strength is no longer satisfactory. This is consistent with the fact that the cutting edge angle of a general end mill that is not subjected to honing is 70 ° to 80 °.

In the roughing end mill, the cutting is performed in the vicinity of the top of the wavy cutting edge, and the entire corrugated contour does not participate in the cutting as shown in the explanatory view of FIG.
Therefore, the position where honing is required is only the part related to cutting, and it varies depending on the cutting conditions, but the feed per blade of the roughing end mill is large even if the feed is 2-3
%, It is sufficient to horn a distance of 5% of the blade diameter from the top of the wavy cutting edge in the radial direction. In the roughing end mill, the wear of the cutting edge at the time of exchanging tools can be tolerated more than that in the general end mill, so the upper limit of honing is limited to 0.1 mm. If it exceeds this value, the initial wear is large and the tool life is shortened. On the other hand, if it is less than 0.02 mm, it does not act as honing and the effect is not exhibited.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings showing embodiments thereof. FIG. 3 is a side view of a roughing end mill according to the present invention, and 1 is a tool body. The tool main body 1 is made of a high hardness type powder high speed tool steel, and has a plurality of twisted corrugated outer peripheral blades 2 on the outer periphery thereof. The roughing end mill has four blades and has a diameter of 20 mm and a blade length of 40 m.
m, total length 140 mm, shank diameter 20 mm. The rake angle of the corrugated outer peripheral blade 2 is 10 °, and as shown in FIG. 4, 0.02 is formed on the flank along the convex contour of the corrugated cutting blade.
Honing is performed by a brush honing method with a width of about 0.03 mm.

FIG. 5 shows a comparative example of the product of the present invention, an untreated product not subjected to honing, and a comparative product subjected to honing by the glass honing method. The other specifications of the roughing end mill are the same as those of the above-described embodiment of the invention product. In the comparative test, cutting was performed at a cutting speed of 30 m / min, a cutting depth of 20 × 20 mm, and the feed at constant intervals. The structural carbon steel S50C is used as the work material for cutting, but the flank wear width is ¼ for the untreated product and ½ for the comparative product for the same length cutting. It became clear that it could be reduced.

[0011]

As described above, according to the present invention, even in heavy cutting with a large cutting load, chipping and chipping are unlikely to occur in the cutting edge and a long life can be obtained, and hard-to-cut materials such as hard materials and tough materials Even in, heavy cutting has become easy.

[Brief description of drawings]

FIG. 1 shows a cutting position of a cutting edge of a roughing end mill.

FIG. 2 shows cutting edge involvement during cutting of a roughing end mill.

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

4 is an enlarged view of a cutting edge portion of FIG.

FIG. 5 shows the results of a cutting test.

[Explanation of symbols]

 1 Tool body 2 Wavy peripheral edge 3 Wavy cutting edge 4 Cutting edge angle

Claims (2)

[Claims] 1. A roughing end mill having a plurality of twisted corrugated peripheral blades on the outer periphery of a solid tool body, wherein the corrugated peripheral blades have a rake angle of 8 to 20 °,
A roughing end mill, characterized in that a flank is horned to have a width of 0.02 to 0.1 mm along a wavy contour. 2. The roughing end mill according to claim 1, wherein honing is performed along the wavy contour from the apex of the wavy outer peripheral blade to the tool radius direction at least 0.05 times the blade diameter. Roughing end mill.