JP2545209Y2 - Cutting tools for soft materials - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a cutting tool for processing a soft material such as styrene foam.

[0002]

2. Description of the Related Art Conventionally, a casting method such as a full molding method in which a mold such as a press die is manufactured by using a foam block which can be lost has been known. That is, in this method, a foam block is cut to produce a vanishing model having the same shape as the mold, and the periphery of the vanishing model is solidified with sand such as resin sand, and then the molten metal is poured into the model portion to cast the model. It is to cast a mold of the same shape as the model. Therefore,
As a cutting process for processing such a foamed block, for example, as shown in Japanese Utility Model Application Laid-Open No. 187421/1984, an indented cutting blade is formed at equal pitch intervals on the rotation direction side of a twist groove provided on the outer periphery. Tools are known. In addition, the applicant of the present invention has proposed a cutting tool such as a foam block as described in Japanese Utility Model Application
No. 4,073,986. This tool has an appropriate combination of the torsion angle of the outer peripheral blade provided on the outer peripheral surface of the tool body, the rake angle with respect to the cross section orthogonal to the axis, and the clearance angle with the cut surface, and smoothes the cut surface and slices chips. Therefore, the casting quality and environmental hygiene are improved.

[0003]

However, in the case of the cutting tool as described above, it is effective to rotate the tool, for example, while feeding it in a direction perpendicular to the tool axis. It cannot be applied to the case of machining while feeding in the tool axis direction like machining. Further, when such a processing is performed by using a conventional general cutting tool, there is a problem that chips become powdery and scatter in a work space, thereby deteriorating the environment.

[0004]

According to the present invention, a torsion angle of an outer peripheral blade provided on an outer peripheral surface of a tool body with respect to a tool axis is at least 40 degrees or more, and a rake angle with respect to a cross section orthogonal to an axis is 40 or more. A cutting tool having a clearance of not more than 20 degrees and a clearance angle of not more than 20 degrees with respect to the cut surface, and having a tip pocket inside the cutting edge portion, a curvature not more than the radius of the tool axis from the outer periphery to the tip of the tool body. An outer radius portion curved inward at a radius and a central flat portion connected to the inside of the outer radius portion are provided, and the straight end portion of the outer peripheral blade parallel to the axial direction and the central flat portion are spirally formed on the outer radius portion. A helical blade to tie is provided. The rake angle of the spiral blade with respect to each radial surface of the outer radius is 40
The temperature was kept constant within the range of degrees to 60 degrees.
In addition, the number of the outer peripheral blade and the spiral blade connected thereto is at least two or more.

[0005]

[Function] The combination of the torsion angle, rake angle, and clearance angle of the outer peripheral blade provided on the outer periphery of the tool main body can be used to smooth the cutting surface and cut off chips when machining while feeding the tool mainly in the direction perpendicular to the tool axis. The rake angle of the spiral blade provided on the outer radius of the tool tip is effective for slicing, and is effective for slicing chips when machining while mainly feeding the tool in the axial direction. Therefore, even in the case of the window cutting process and the through process, the powdery chips are not scattered in the working space, and the environmental health is not deteriorated.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a cutting tool for soft material according to the present invention will be described with reference to the accompanying drawings. FIG. 1 is a perspective view of the tip of the present cutting tool, FIG. 2 is a plan view of the same, and FIG.

[0007] The cutting tool of the present invention is proposed as a tool for producing a disappearing model such as styrene foam, for example.
As shown in FIG. 3, the tool main body 1 includes a body portion 2 having a blade portion and a shank portion 3.

The body portion 2 is provided with two peripheral blades 4 on the outer peripheral surface parallel to the tool axis OO, and the body portion 2 is provided with two spiral blades 5 at the tip end thereof. The outer peripheral blade 4 and the spiral blade 5 are continuous.

The outer peripheral blade 4 has a torsion angle φ of 40 degrees or more with respect to the tool axis OO, and as shown in FIG. The rake angle γ with respect to Q is in the range of 40 to 60 degrees. In addition, the clearance angle α with respect to the cut finish surface PP is within 20 degrees.
In the case of the embodiment, the rake angle γ is 50 degrees and the clearance angle α is 20 degrees. That is, the thickness angle δ of the cutting edge where the rake face 6 and the flank 10 intersect is set to 20 degrees.

A chip pocket 7 is formed inside the rake face 6 to facilitate chip discharge.

When the tool body 1 is rotated and fed in a direction perpendicular to the tool axis OO, the outer peripheral blade 4 cuts the cut surface PP. By giving such a strong torsion angle φ, a so-called pulling effect is exhibited, and the cut surface can be finely finished.

Further, the rake angle γ with respect to the section orthogonal to the axis QQ
If the rake angle γ is as large as about 50 degrees, the cutting edge will be in a state where the cutting edge is set up and the chip will be peeled off. It is in a state where it is cut in a posture where it is laid down, and it does not become scooped.

Then, the twist angle φ, the rake angle γ,
Experiments show that, depending on the combination of clearance angle α, if the tool is sent in the direction perpendicular to the tool axis OO, chips can be processed into slices, and not only can the cutting surface be finished beautifully, but also the cutting efficiency can be increased. Has been confirmed.

Incidentally, in the case of the present invention, the rake angle γ50 degrees, the clearance angle α20 degrees, and the thickness angle δ20 degrees of the cutting edge are also kept constant at the spiral blade 5 on the tip side of the body 2.

That is, as shown in FIG.
An outer radius portion 8 that bends from the outer periphery toward the inside is provided at the tip end of the, and the radius of curvature r of the outer radius portion 8 from the center of curvature x is equal to or smaller than the radius of the tool axis. The inside of the outer radius part 8 is a central flat part 9,
The front is flat.

That is, as shown in FIG.
The inside of a circle (broken line) centered on is a central flat portion 9 and the outside thereof is configured as an outer radius portion 8.

The tool shaft (OO) of the outer peripheral blade 4 is used.
A helical blade 5 is provided at the end of the tip end (straight end portion e) parallel to the straight line), and the helical blade 5 is helically provided along the outer circumferential radius portion 8 and extends from the straight end portion e. It is connected to the central flat part 9 when it is turned about 180 degrees. In the case of the embodiment, the two spiral blades 5 connected to the central flat portion 9 are joined at a position where they face each other.
Note that the turning angle of the spiral blade 5 does not necessarily need to be 180 degrees, and may be, for example, 270 degrees.

Next, the shape of the spiral blade 5 will be described with reference to FIG. FIG. 5 is an axial sectional view of the spiral blade,
(A) is a cross-sectional view taken along the line AA of FIG. 2, and (B) is an OB of FIG.
FIG. 3C is a sectional view taken along line OC of FIG. 2, and FIG. 3D is a sectional view taken along line DD of FIG. 2.

As described above, the rake angle γ50 °, the clearance angle α20 °, and the thickness angle δ20 ° of the cutting edge are maintained in all the portions of the spiral blade 5. That is, as shown in (b) to (d) of FIG. 5, the rake angle γ of the outer radius part 8 with respect to the radial surface xR about the center of curvature x is constant at 50 degrees, and the cutting finish Clearance angle α to plane PP
Is constant at 20 degrees. The spiral blade 5 is also provided with a chip pocket connected to the rake face, similarly to the outer peripheral blade 4.

The turning angle of the spiral blade 5 corresponds to the torsion angle φ of the outer peripheral blade 4, and the turning angle of the spiral is 18 as in the embodiment.
In the case of 0 degree, when the tool diameter is 30 mm and the radius of curvature r of the outer radius part 8 is 10 mm, it corresponds to a torsion angle φ of 78.8 degrees. By the way, when the spiral turning angle is set to 270 degrees,
This corresponds to a twist angle of φ82 degrees.

Then, by the configuration of the spiral blade 5,
Even if the rotating tool body 1 is fed in the axial direction, the cutting surface can be finished finely and the chips can be sliced. In other words, there is no problem that the window cutting process, the through process, and the like are finely finished and the chips are scattered.

The number of the spiral blade 5 and the outer peripheral blade 4 is not limited to two as in the embodiment, and may be more. The cutting tool of the present invention is not limited to the soft material shown in the embodiment but may be, for example, It goes without saying that the present invention can be applied to other resin materials, wood, and the like.

[0023]

[Effects of the Invention] As described above, the cutting tool for soft material of the present invention slices chips even when cutting while feeding the tool in the axial direction, such as through-hole processing or through processing of a foam block. Shape, and the finished surface can be finely finished. For this reason, it is possible to prevent the problem that chips are scattered to the surroundings to impair environmental hygiene, and that the cut surface becomes rough, for example, causing a bite in the sand when used as a mold disappearing model.

[Brief description of the drawings]

FIG. 1 is a perspective view of a tip of the present cutting tool.

FIG. 2 is a plan view of the same.

FIG. 3 is a front view in which a tip is partially sectioned.

FIG. 4 is a partially enlarged sectional view of an outer peripheral blade.

5 is an axial sectional view of the spiral blade, (A) is a sectional view taken along line AA of FIG. 2, (B) is a sectional view taken along line OB of FIG. 2,
(C) is a cross-sectional view taken along the line OC of FIG.
Line cross section

[Explanation of symbols]

 Reference Signs List 1 tool main body 4 outer peripheral blade 5 spiral blade 8 outer peripheral round part 9 central flat part α relief angle γ rake angle φ torsion angle e straight end part r radius of curvature

Claims (2)

(57) [Scope of request for utility model registration] 1. A torsion angle of an outer peripheral blade provided on an outer peripheral surface of a tool body with respect to a tool axis is at least 40 degrees or more, a rake angle with respect to a cross section orthogonal to the axis is 40 to 60 degrees, and a clearance angle with respect to a cut surface is 20 degrees. A cutting tool having a tip pocket within the inside of a cutting edge portion, and a tip portion of the tool body, an outer radius portion curved inward from the outer periphery with a radius of curvature equal to or less than a radius of a tool axis, and the outer radius portion. A central flat portion is provided continuously inside the portion, and the outer radius portion is provided with a helical blade that spirally connects the straight end portion of the outer peripheral blade parallel to the axial direction and the central flat portion in a spiral, and each of the outer radius portions is provided. A cutting tool for a soft material, wherein a rake angle of a spiral blade with respect to a radial surface is kept constant within a range of 40 degrees to 60 degrees. 2. The soft material cutting tool according to claim 1, wherein the number of the outer peripheral blade and the helical blade connected thereto is at least two.