JPH079237A - End mill for processing of tapered groove - Google Patents

Abstract

PURPOSE:To enhance the machining efficiency without impairing the rigidity of a tool by forming polygonal the section perpendicular to the tool axis and providing a channel-form cutter groove along the ridge of a cutting edge, wherein a superhard alloy is used to the tool material. CONSTITUTION:The tool material of an end mill concerned consists of a superhard alloy, and its section perpendicular to the tool axis is formed polygonal. A channel-form cutter groove 3 is provided having a size less than one half of the length of one edge member of the polygon along the ridge of the cutting edge so that the rigidities of the cutting edge 2 and tool are maintained, and small splash generated at machining is accommodated temporarily. To suppress burrs generated at the oversurface of a work to be processed at machining, the twist of an outside circumferential cutting edge 2 is oriented leftwise, and the twist angle is ranged between 5-20 deg., preferably between 10-15 deg., where the influences upon the machining resistance and the accuracy of the surface to be processed are taken into consideration.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a taper groove processing end mill for processing a rib groove of a resin product, an aluminum die cast product or the like or a groove having a tapered cross section of a cavity portion.

[0002]

2. Description of the Related Art Generally, when a resin, a taper-shaped groove for forming a rib of a die for aluminum die casting (abbreviated as a rib groove), etc. is processed, it is performed by electric discharge machining or cutting.

Further, as end mills having the same purpose as that of the present invention and capable of performing cutting processing with higher efficiency, there are Fukukai 62-54654 and Fukukai 2-33317 devised by the same applicant as the present invention. These have a regular polygonal shape in the cross section perpendicular to the tool axis, have excellent tool rigidity, and enable long-time machining without breaking the machining of thin and deep rib grooves, etc., which is highly efficient and highly accurate. This is an end mill that can be processed.

[0004]

However, in the end mills described above, the tip pocket is required to obtain the tool rigidity, while the demand for more efficient and highly accurate machining of narrower and longer rib grooves is increasing. When a very narrow, narrower, longer rib groove or the like is machined, there is a problem that the chip discharge performance deteriorates, the cutting resistance increases, the tool is easily broken, and the machining accuracy cannot be obtained.

Further, in the processing method using the above-mentioned end mill, the end blade is mainly used, and 0.03 to 0.1 m per time is used.
Grooves were machined to a final depth of about 10 to 15 mm by repeating a very slight cutting in the axial direction of the tool of about m.

For this reason, the number of times of cutting is large, and the method of increasing the feed rate in order to improve the efficiency has been adopted, but there is a limit in terms of machining accuracy and tool life, and further cutting in the axial direction of the tool is required. However, there is a problem in that the increase in the number is not possible because it causes chip clogging and is due to breakage of the tool.

[0007]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and provides an end mill for taper groove machining which can improve the cutting efficiency without impairing the tool rigidity.

[0008]

In order to achieve the above object, the present invention has a polygonal cross-sectional shape perpendicular to the tool axis, and the length of one side of the polygon along the cutting edge line. 1 / of
A concave blade groove of 2 or less is provided, and a super hard alloy is used as a tool material.

Further, the twist of the outer peripheral cutting edge is left twist, and the twist angle is in the range of 5 ° to 20 °.

[0010]

In order to achieve the same purpose as the present invention, the application of the same applicant is made in Japanese Utility Model Laid-Open No. 62-54654 and Japanese Utility Model Laid-Open No. 2-3.
There is 317, but the main part of this is further improved and clarified.

By applying the present invention, it has become possible to process finer and longer rib grooves and the like with higher efficiency and accuracy.

[0012] Here, if the cutting groove is a concave groove having a length equal to or less than 1/2 of the length of one side of the polygon along the cutting edge ridge, the rigidity of the cutting edge and the tool can be maintained, and it is generated during cutting. It was possible to temporarily store the small chips that were produced, to prevent clogging of chips and to improve the dischargeability. Therefore, the breakage of the tool was suppressed and the tool life was improved. Further, since the sharpness is good, the cutting resistance is reduced, the machining accuracy is improved, and the cutting amount in the axial direction of the tool can be increased. Furthermore, by setting the concave blade groove to ⅓ or less of the length of one side of the polygon, in addition to the above-mentioned action, it is possible to obtain further cutting edge and tool rigidity.

Further, in order to suppress the burrs generated on the upper surface of the workpiece during cutting, the twist of the outer peripheral cutting edge is set to the left twist, and the twist angle is taken into consideration in consideration of the influence on the cutting resistance and the precision of the machined surface. Was set in the range of 5 ° to 20 °, but it is desirable to set it in the range of 10 ° to 15 ° in order to obtain further effects.

TiN, TiCN and TiAlN
It goes without saying that the tool life can be further extended by coating a hard film such as.

[0015]

1 and 2 show an embodiment of the present invention. Ultra fine particle cemented carbide is used as a tool material, and TiC is used as a hard film.
This is an end mill for N-coating with a tool tip blade diameter of 1 mm, a taper angle of 1 °, a right blade left twist, a helix angle of 12 °, and a cross section perpendicular to the tool blade axis that is substantially regular hexagonal.

Further, the core thickness of the blade portion is set to 86.6% of the tool blade diameter equivalent to that of the conventional product shown in FIGS. 3 to 4, and further, one side of the hexagon in the cross section perpendicular to the tool shaft blade portion axis. 1/3 of the length
The concave blade groove is added.

The product of the present invention has the same tool rigidity as that of the conventional product, can suppress clogging of chips, prevent breakage of the tool, and have a long life.

[0018]

As described above, according to the present invention, it is possible to improve the cutting efficiency without deteriorating the tool rigidity, and to perform the taper groove machining with high accuracy and high efficiency.

[Brief description of drawings]

FIG. 1 is a side view showing an embodiment of the present invention.

FIG. 2 is a sectional view of the blade portion of FIG.

FIG. 3 is a side view showing an example of a conventional product.

4 is a sectional view of the blade of FIG.

[Explanation of symbols]

 1 main body 2 outer peripheral cutting edge 3 blade groove 4 core thickness 5 chip pocket θ helix angle

Claims (2)

[Claims] 1. A tapered groove machining end mill used for machining a groove having a tapered shape on both side surfaces, wherein a cross section of the tool at right angles forms a polygon, and a length of one side of the polygon along a cutting edge line. An end mill for taper groove processing, characterized by having a concave blade groove of ½ or less of the height and using a super hard alloy as a tool material. 2. The twist of the outer peripheral cutting edge is left twist,
The end mill for taper groove machining according to claim 1, wherein the twist angle is in the range of 5 ° to 20 °.