JPH0760527A - End mill for rough finishing - Google Patents

Abstract

PURPOSE:To improve the machining efficiency and machining precision by forming an edge diameter of an outer circumferential cutting edge for rough finishing on the end tip side to be smaller than an edge diameter of an outer circumferential cutting edge for finishing on the shank side. CONSTITUTION:An end mill is provided with an outer circumferential cutting edge 4 of a wavy form for rough finishing on the end tip side inside an effective edge length, and an outer circumferential cutting edge 5 for finishing as a normal helical edge on the shank 3 side. An edge diameter of the outer circumferential cutting edge 4 for rough finishing on the end tip side is set to be smaller than an edge diameter of the outer circumferential cutting edge 5 for finishing in a range of 0mm to 1mm, or by 0.2mm preferably. Contact distance of the outer circumferential cutting edge 4 with a work at the time of rough finishing is thus decreased to reduce cutting resistance. In addition, in a finishing process, the process can be performed with the outer circumferential cutting edge 5 or finishing in a similar program to that for rough finishing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an end mill that efficiently processes from roughing to finishing with one end mill.

[0002]

2. Description of the Related Art As an end mill that processes from roughing to finishing with a single end mill, the actual machine is 57-1.
3113. This is one in which an outer peripheral cutting edge for rough machining and an outer peripheral cutting edge for finish machining, each having the same diameter, are provided on the same shaft by ½ of the effective blade length, thus improving the efficiency. Further, in general, when performing long hole machining or notch machining on a plate-shaped work material, a two-blade or four-blade end mill having a normal twist was used. Especially in the processing of the drain hole of the aluminum sash,
A dedicated 1- or 2-flute end mill, commonly referred to as aluminum, was used.

[0003]

However, although the time required for tool exchange is not necessary in the end mill of the actual open cutting machine 57-13113, the outer peripheral cutting edge for roughing and the outer peripheral cutting edge for finishing are of the same diameter. However, due to the runout of the tool at the time of cutting, when the operation of the end mill at the time of roughing is the same as that at the time of finishing, the uncut portion of the roughened surface was left. Therefore, when the NC machine is used, there is a problem that the operation itself of the end mill has to be changed, for example, the program has to be changed. In particular, in the case of plunging, rough cutting requires linear cutting in the axial direction of the tool, whereas arc cutting is inevitable in finishing, which causes problems in processing time and time required for programming.

In general, when cutting a soft metal such as aluminum, since the chips are elongated and curl large, the end mill to be used has a small number of blades and a large chip pocket. , That is, using a dedicated end mill. Since the single-blade end mill naturally has a small number of blades and a small tool cross-sectional area, a tool having an elongated shape such as an end mill has a limit in feed rate because vibration during cutting becomes too large. On the other hand, the two-blade end mill for aluminum has
This is advantageous in that the cross-sectional area of the tool is large, and although the feed rate can be increased, the feed rate cannot be proportionally increased because the chip pocket is smaller than one blade.

Regarding the vibration at the time of cutting, it is 1
The discontinuity is reduced and vibration is reduced compared to a single-blade blade, but in the processing of thin-walled materials such as aluminum sashes, if it is a simple end mill with a twisting blade, the stronger the helix angle of the outer peripheral blade is, the stronger the work material becomes. The longer the contact cutting edge length and the stronger the helix angle, the greater the force for lifting the thin material and the greater the vibration. Along with this, the cutting noise became loud and there was a problem in the work environment. With an end mill with 3 or more flutes, the chip pocket becomes smaller than with 2 flutes, and there is a problem of early life due to clogging of chips, and at the time of grooving, the number of simultaneous cutting blades increases, so the cutting resistance also increases, On the contrary, the vibration will be larger in the thin material.
Therefore, there was a problem that the feed could not be raised. The present invention has been made to solve the above problems, and an object of the present invention is to provide an end mill capable of efficiently cutting a plate-shaped work material from roughing to finishing with one end mill. .

[0007]

In order to achieve the above object, the present invention provides an outer peripheral cutting edge for rough machining on the end edge side of the effective blade length, and an outer peripheral cutting edge for finishing on the shank side, and The outer peripheral cutting edge for rough machining on the end edge side has a diameter smaller than the outer peripheral cutting edge for finishing on the shank side within a range of more than 0 mm and 1 mm or less. Also,
The number of peripheral cutting edges for finishing is equal to or greater than the number of peripheral cutting edges for roughing. Furthermore, the twist angle of the outer peripheral cutting edge with respect to the tool axis is 15 ° to 50 °,
And the diameter of the inscribed circle at the bottom of the blade groove (hereinafter referred to as the core thickness)
Is 30% to 65% of the blade diameter, and has a rake-shaped rake face in which the rake angle of the outer peripheral cutting edge in the cross section perpendicular to the tool axis is in the range of 10 ° to 25 °. The number of blades is two. Furthermore, depending on the purpose of use, the end cutting edge of the tool tip is convex or 1 ° to 3 °
The outer peripheral cutting edge for roughing may be wavy or trapezoidal in the range of 0 °.

[0008]

The present invention is applied to Japanese Patent Application No. Hei.
This is a further expansion of the application field of -174981. By applying the present invention, it is possible to reduce the contact distance between the outer peripheral cutting edge for rough machining and the work material during rough machining and reduce the cutting resistance. In other words, the feed speed was greatly increased compared to the conventional end mill, and in finishing, the tool could be machined in the same program as rough machining simply by shifting the tool in the tool axial direction, improving machining efficiency and machining accuracy. Further, the outer peripheral cutting edge for roughing and the outer peripheral cutting edge for finishing can be made continuous or not, and the shape and the number of each outer peripheral cutting edge can be freely set and can be adapted according to the purpose. It became so. Here, it is possible to provide a cutting edge that works in the same way as a normal end blade on the end edge side of the outer peripheral cutting edge for finishing, but the outer peripheral cutting edge for roughing and the outer peripheral cutting edge for finishing Diameter difference exceeds 0 and 1
Since it is less than or equal to mm, it is not particularly required except in special cases.

Further, since the machining allowance in finishing is minute, it is possible to further increase the feed rate by increasing the number of outer peripheral cutting edges for finishing. Still further, according to the present invention, a large chip pocket can be secured by setting a helix angle, a core thickness, and a rake angle, the chip is not clogged even when groove cutting is performed, sharpness is improved, and a soft material such as aluminum is used. It became suitable for the material.

[0010]

1 to 3 show an embodiment of the present invention, in which a blade diameter is 10 mm, a peripheral blade has a helix angle of 45 ° and a core thickness of 5
0%, the rake angle of the outer peripheral blade is 20 °.
In addition, a corrugated outer peripheral cutting edge for rough machining is provided on the end cutting edge side within the effective blade length, and an outer peripheral cutting edge for finishing processing, which is a normal twisting blade, is provided on the shank side, and an outer peripheral cutting edge for rough machining on the end cutting edge side. The blade diameter of is smaller than that of the outer peripheral cutting edge for finishing on the shank side by 0.2 mm. In addition, Table 1 shows a comparison of cutting performance when processing an aluminum plate into a long hole having a width of 10 mm. When machining with a conventional 2-flute end mill for aluminum only, the cutting resistance is large and the vibration during machining is large. The maximum feed rate is 120 mm / min, and it took 2 minutes to machine one long hole. . In addition, the cutting noise was too loud to withstand.

Next, when the roughing end mill and the two-blade end mill are used together, including the time for automatic tool change, 2.
It took a minute. Here, the roughing end mill has a blade diameter of 9
The thing of mm was used. Furthermore, the actual development Sho 57-13113
The end mill shown in Fig. 3 is a result of a trial cutting with a blade diameter of 10 mm and 2 blades and a cutting test. The required time is 1.
Although it was able to be shortened to 6 minutes, there was some uncut portion on the rough surface and the surface roughness was extremely inferior at 18 μm. If the cutting surface roughness is emphasized, an end mill with a blade diameter of less than 10 mm is required, and even if an end mill with a blade diameter of less than 10 mm is used,
The programming time and processing time increase, and the problem that the required time is longer than when using two end mills together occurs.

Finally, when the product of the present invention is used, the required time can be shortened to 1.6 minutes and the cutting surface roughness is 3.1.
It was as good as μm and the processing accuracy was satisfactory. Here, as a machining method, after rough machining with the outer peripheral cutting edge for rough machining on the end blade side, the tool was further fed in the tool axial direction, and finish machining was performed with the cutting edge for finish machining on the shank side.

[0013]

As described above, according to the present invention, the working efficiency and the working accuracy can be improved, and the roughing and the finishing can be carried out by one end mill, and the tool cost can be reduced.

[Brief description of drawings]

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

FIG. 2 is a side view of FIG.

FIG. 3 is a detailed view of the outer peripheral cutting edge of FIG. 1 developed.

[Explanation of symbols]

 1 Main body 2 End blade 3 Shank 4 Outer peripheral cutting edge for roughing 5 Outer peripheral cutting edge for finishing θ Helix angle α Rake angle

[Table 1]

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[Procedure amendment]

[Submission date] May 27, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be amended] Title of invention

[Correction method] Change

[Correction content]

[Title of the Invention] End mill for roughing and finishing

Claims (3)

[Claims] 1. An end mill having a plurality of twisted outer cutting edges on the outer circumference of a tool body, wherein an outer cutting edge for roughing is provided on the end cutting edge side of the effective cutting length, and an outer cutting edge for finishing is provided on the shank side. Also, the end mill for roughing / finishing is characterized in that the diameter of the outer peripheral cutting edge for roughing on the end edge side is smaller than the blade diameter of the outer peripheral cutting edge for finishing on the shank side within a range of more than 0 mm and 1 mm or less. 2. The roughing / finishing end mill according to claim 1, wherein the number of peripheral cutting edges for finishing is equal to or greater than the number of peripheral cutting edges for roughing. 3. The twist angle of the outer peripheral cutting edge with respect to the tool axis is 15 ° to 50 °, and the diameter of the inscribed circle of the blade bottom of the blade groove is 30% to 65% of the blade diameter. The outer peripheral cutting edge in the cross section has a rake face having a rake angle in the range of 10 ° to 25 °, and the outer peripheral cutting edge for rough machining has two blades. An end mill for roughing and finishing as described in 1 to 2.