JPH0556305U - Spheroidal graphite cast iron for holder - Google Patents

Abstract

(57) [Summary] [Objective] The present invention absorbs vibrations by using toughness spheroidal graphite cast iron for parts of the holder body, supporters, etc., improves vibration damping action, and enables highly efficient cutting. The purpose is to provide a tool. [Structure] The holder of the present invention absorbs vibration at the portion where the spheroidal graphite cast iron is applied, allows smooth and quiet cutting, reduces vibration and chipping, and provides a better cutting surface and prolongs the chip life. In addition, it can be used under cutting conditions equivalent to or better than conventional ones, improving efficiency.

Description

[Detailed description of the device]

[0001]

[Industrial application]

 The present invention mainly relates to various throw-away type holders used for cutting metal.

[0002]

[Prior Art]

 Conventional throw-away type cutting tools include end mills, face mills, and bites, which are used for each purpose. The throw-away type cutting tool is composed of a chip that corresponds to the cutting edge and a body that holds the chip, and is used by fastening it to the machine body via a holder. Here, the tip is the part that constitutes the cutting edge of the cutting tool, and various tool materials such as cemented carbide are selected and used according to the application. The main body has a structure that gives the chip suitable specifications for cutting, allows easy chip replacement, and grips firmly, but it is usually used for structures such as Cr-Mo steel because it requires strength to withstand the cutting load. Alloy steel is used. Further, the holder has a function of gripping the tool body and fastening it to the machine tool while maintaining an appropriate overhang, but like the tool body, it requires strength and rigidity, and structural alloy steel is also used.

The throw-away type cutting tool has an advantage that a new cutting edge can be repeatedly used only by replacing the tip, but since the shape of the tip is limited, it is not always possible to design a cutting edge with emphasis on machinability. . Therefore, due to the balance of cutting conditions such as depth of cut and mechanical strength, vibration during cutting is severe, cutting noise becomes loud, chipping life is shortened due to chipping, etc., resulting in poor accuracy of processed products. In order to avoid this, the method of lowering the depth of cut and other cutting conditions is adopted, and the original performance of the tool is not fully utilized.

[0003]

[Problems to be solved by the device]

 Especially when heavy cutting is performed, cutting resistance is increased, and vibration and cutting noise are large. Machines with low rigidity can no longer handle changes in cutting depth and other cutting conditions. Even if the machine has sufficient strength, lowering the cutting conditions caused problems in machining efficiency, and vibration and noise caused problems not only in terms of accuracy but also in terms of the environment. As described above, chattering and vibration due to load during cutting are remarkable, and if these can be reduced, the effect of the throw-away type cutting tool will be further enhanced. The present invention eliminates the above drawbacks, and provides a throw-away type holder capable of stable and quiet cutting with little vibration.

[0004]

[Means for solving the problem]

 In order to achieve the above object, the present invention uses austempered spheroidal graphite cast iron, which has a high vibration damping effect and is excellent in strength, for the body or parts of the throw-away tool. It is known that austempered spheroidal graphite cast iron generally absorbs and attenuates vibrations more than steel materials, that is, has a high vibration damping effect.If this is applied to the material of the main body, vibrations can be suppressed and Smooth and quiet cutting is possible. However, according to the conventional concept, spheroidal graphite cast iron was inferior in strength to steel and was not always able to withstand cutting resistance. In particular, the bending toughness is generally low, and there is a risk of damage during cutting, which is the most unfavorable cutting tool.

However, an austempered spheroidal graphite cast iron having a strength comparable to that of steel has been put into practical use, and the strength has also exceeded 900 N / mm ² , and if this austempered spheroidal graphite cast iron is used, the vibration damping effect is obtained. In addition to the excellent effect, it also suppresses vibration and chipping of the chip due to vibration, resulting in a better cutting surface, resulting in longer tool life. This kind of effect is noticeable when the distance between the machine tool body and the cutting tool, that is, when the overhang is long, is not only adopted in the tool body, but also enables stable cutting to a holder with a long overhang and improves the cutting quality. It will raise the work environment such as noise and improve the work environment. Furthermore, by subjecting the retained austenite to a surface hardening treatment such as shot peening, the hardness of the holder surface is increased and it is possible to sufficiently withstand contact with chips.

[0006]

【Example】

 FIG. 1 shows a bite holder, and FIG. 2 shows a front milling cutter. As a material for the main body 1 or 2, the supporter 3, and the wedge portion 4, a conventional Cr-Mo steel is applied again to the tough spheroidal graphite cast iron. Further, in the cutting of carbon steel by the throw away tool shown in FIG. 1, the product of the present invention and the conventional product were compared. The results are shown in FIG. 3. While the surface roughness of the conventional product deteriorated due to chipping, the product of the present invention did not show chipping, and a good cutting surface was obtained. Furthermore, by applying the spheroidal graphite cast iron, there is an effect that the portion where the spheroidal graphite cast iron is used can be easily formed and the material and processing cost can be reduced.

[0007]

[Effect of the device]

 As described above, according to the present invention, even in a machine having low rigidity, vibration is absorbed by the part to which the spheroidal graphite cast iron is applied, smooth and quiet cutting can be performed, and vibration and chipping are reduced, resulting in better cutting. The surface is obtained and the chip life is extended. In addition, it can be used under the same or higher cutting conditions as the conventional one, improving efficiency. Furthermore, the reduction of vibration due to cutting leads to stable machine accuracy and does not adversely affect other machines around.

[Brief description of drawings]

FIG. 1 is a side view of an application example of the present invention.

FIG. 2 is a side view of another application example of the present invention.

FIG. 3 is an explanatory view showing a comparison result between a throw-away type cutting tool to which the present invention is applied and a conventional throw-away type cutting tool.

[Explanation of symbols]

 1 Tool holder 2 Front milling cutter 3 Supporter 4 Wedge part 5 Throw-away tip

Claims (2)

[Scope of utility model registration request] 1. A spheroidal graphite cast iron for a holder, characterized in that spheroidal graphite cast iron excellent in strength and vibration damping property is used for a holder of a body or a part or a throw-away tip for holding the body. 2. A spheroidal graphite cast iron for a throw-away tip holder, which is obtained by subjecting the spheroidal graphite cast iron according to claim 1 to surface hardening treatment by shot peening.