JPH079236A - Roughing end mill - Google Patents

Abstract

PURPOSE:To provide an end mill which can perform high efficiency processing of a soft material such as aluminum and can reduce vibratory noises. CONSTITUTION:A roughing end mill having an undulately twisted outside circumferential cutting edge at the periphery of the tool body has a rake face, wherein the twist angle theta of the outside circumferential cutting edge to the tool axis ranges between 15-50 deg. while the diameter of the inscribing circle to the cutter groove bottom ranges 30-60% of the cutter diameter, and the rake angle alphaof the outside circumferential cutting edge on the section perpendicular to the tool axis ranges 10-25 deg. The end mill is equipped with two of such cutting edges.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an end mill for efficiently cutting a soft material such as aluminum.

[0002]

2. Description of the Related Art Generally, when a soft material such as aluminum is cut, the chips are elongated and curl greatly. Therefore, the end mill used has a small number of blades and a large chip pocket. Was essential. Therefore, for the notch processing of the long hole for draining the aluminum sash or the combined portion, a dedicated one- or two-blade end mill generally called for aluminum has been used.

However, even with a dedicated end mill, since the aluminum sash itself is thin and the cross-sectional shape is complicated, the gripping strength of the work material is weakened, so that vibration during cutting increases and feed rate increases. There was a limit.

In addition, since the single-blade end mill naturally has a small number of blades and a small cross-sectional area of the tool, an elongated tool such as an end mill has a limit in feed rate because vibration during cutting becomes too large. On the other hand, a two-blade end mill for aluminum is advantageous in that the number of flutes and the cross-sectional area of the tool are increased, and the feed rate can be increased, but conversely the chip pocket is smaller than that of a single-blade, so the feed rate is proportionally increased. I couldn't.

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 the working environment was deteriorated.

In an end mill having three or more flutes, the chip pocket becomes smaller than that of the two-flute, and there is a problem of early life due to clogging of chips. In addition, when grooving, the number of simultaneous cutting blades increases, so that the cutting resistance also increases. The vibration becomes larger on the contrary with a thin material. Therefore, there was a problem that the feed could not be raised.

[0007]

An object of the present invention is to solve the above problems, and an object of the present invention is to provide an end mill capable of processing a soft material such as aluminum with high efficiency and reducing vibration noise. .

[0008]

In order to achieve the above object, the present invention has a corrugated outer peripheral helix blade of a two-blade end mill, and has a helix angle of the outer periphery of 15 ° to 50 ° and inscribed in the blade bottom. The circle (core thickness) is 30% to 60% of the blade diameter, and the rake angle of the outer peripheral cutting edge is 10 ° to 25 °. Further, depending on the purpose of use, the end cutting edge at the tip of the tool may be convex or concave in the range of 1 ° to 30 °. Furthermore, the wavy shape of the twisted outer peripheral cutting edge may be trapezoidal.

[0009]

[Function] By making the outer peripheral helical blade wavy, the contact distance between the cutting edge and the work material can be reduced and cutting resistance can be reduced. That is, the feed rate can be significantly increased as compared with the conventional end mill. Further, the effect of reducing the cutting resistance does not change even if the twist angle of the outer peripheral blade is increased to improve the sharpness.

The core thickness of an end mill for steel is usually 60% to 70% of the blade diameter, while the core thickness of the present invention is 3%.
By making it as small as 0% to 60%, a large chip pocket can be secured, chips do not become clogged even when performing groove cutting, and the cutting resistance at the outer peripheral cutting edge is reduced, so the tool cross-sectional area is for steel. Even if the number is reduced, high feed is possible with no problem in tool rigidity.

Further, by setting the rake angle of the outer peripheral blade to be larger than the rake angle of 5 ° to 15 ° for normal steel, the cutting edge is sharpened and the sharpness is improved, so that it is suitable for soft materials such as aluminum. Furthermore, by selecting the end cutting edge shape and the corrugated shape of the outer peripheral cutting edge, it is possible to perform machining that suits various purposes, such as when roundness is required when drilling or when the condition of the machined surface is a problem. I can do it efficiently.

[0012]

1 to 4 show an embodiment of the present invention, in which the blade diameter is 10 mm, the outer 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 °.
5 to 7 show an example of a conventional product, which is a single-blade end mill for aluminum with a blade diameter of 10 mm, in which the peripheral blade has a helix angle of 30 ° and a rake angle of 20 °. Further, FIGS. 8 to 10 show examples of other conventional products, in which a blade diameter of 2 mm
This is a single-blade end mill for aluminum, and the peripheral blade has a helix angle of 45 °, a rake angle of 20 °, and a core thickness of 50%.

FIG. 11 shows the cutting performance when grooving the aluminum sash. With the conventional product (single blade), the vibration noise is large as a whole, and the rattling noise of the tool becomes extremely loud at the feed of 600 mm / min, and the limit becomes large. Became. In addition, conventional products (2-flute)
Then, the cutting noise is lower than that of a single blade, but the feed is 800 m
The machine became overloaded and stopped due to clogging of chips at m / min.

Since the product of the present invention has a small cutting resistance, it can be cut even under the condition that the feed rate is 1000 mm / min, and the chips are divided by the effect of the corrugated edge, so that the chips are not clogged. Furthermore, since the cutting resistance is low, there is almost no change in the cutting vibration noise even if the feed is increased,
In a stable state, there is no problem in the working environment.

[0015]

As described above, according to the present invention, it is possible to perform high-efficiency processing and suppress cutting vibration even when processing a soft metal such as an aluminum sash and having a weak work material strength. Became.

[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 sectional view of the blade portion of FIG.

FIG. 4 is a detailed view of the outer peripheral cutting edge of FIG. 1 developed.

FIG. 5 is a front view showing an example of a conventional product.

FIG. 6 is a side view of FIG.

7 is a sectional view of the blade of FIG. 5 at a right angle to the axis.

FIG. 8 is a front view of an example of another conventional product.

FIG. 9 is a side view of FIG.

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

FIG. 11 is an explanatory diagram showing cutting effects of the product of the present invention and the conventional product.

FIG. 12 is a front view of another embodiment of the present invention.

FIG. 13 is a detailed view showing the outer peripheral cutting edge of FIG. 12 in a developed state.

FIG. 14 is a front view of another embodiment of the present invention.

FIG. 15 is a front view of another embodiment of the present invention.

[Explanation of symbols]

 1 Main body 2 Outer peripheral cutting edge 3 Core thickness θ Helix angle α Rake angle

Claims (4)

[Claims] 1. A roughing end mill having a twisted outer peripheral cutting edge on the outer periphery of a tool body, wherein the cutting edge has a wavy shape, and the twist angle (θ) of the outer peripheral cutting edge with respect to the tool axis is 1.
5 ° to 50 °, the diameter of the inscribed circle of the blade groove bottom is 30% to 60% of the blade diameter, and the rake angle (α) of the outer peripheral cutting edge in the cross section perpendicular to the tool axis is 10 ° to Roughing end mill having a rake rake face in the range of 25 ° and two blades. 2. The roughing end mill according to claim 1, wherein the end cutting edge at the tip of the tool has a convex shape. 3. The roughing end mill according to claim 1, wherein the end cutting edge at the tip of the tool is concave in the range of 1 ° to 30 °. 4. The roughing end mill according to claim 1, wherein the twisted outer peripheral cutting edge has a trapezoidal wavy shape.