JPH0192073A - Cutting wheel for cutting casted iron article - Google Patents

Abstract

PURPOSE:To reduce the deformation of a base metal in the high speed cutting and prevent the breakage of the base metal by drastically reducing the thermal expansion coefficient of the base metal by preparing the disc-shaped base metal for a cutting wheel from the Fe-Ni alloy containing Ni in 30-50vol.%. CONSTITUTION:A disc-shaped base metal 2 is formed from the Fe-Ni group alloy having a Ni content of 30-50%. Therefore, the thermal expansion coefficient of the base metal 2 is reduced drastically. Therefore, even if the temperature is raised by the friction heat of a cutter and the side surface of a cutting wheel 1 in the high speed cutting, the base metal 2 is hardly deformed. Therefore, the cut width is not increased, and the cutting performance is not deteriorated, and the friction resistance is hardly increased, and the base metal 2 is not applied with a large stress, and the base metal 2 is protected from being broken, and the durability of the base metal 2 is increased.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a cutting wheel for cutting cast iron castings, and in particular, to a cutting wheel for cutting cast iron castings, and in particular to a disc made of an Fe-Ni alloy that contains appropriate amounts of nickel and iron and has low thermal expansion. This is an alloy that prevents damage to the cutting wheel and improves its durability.

[Conventional technology]

2. Description of the Related Art Conventionally, high-speed cutting machines have been used as devices for mechanically cutting metal materials, for example, cutting and removing sprues, feeders, etc. of cast products, or cutting steel pipes. This high-speed cutting machine is generally rotatably equipped with a cutting wheel that is provided with cutting edges in the circumferential direction of the outer peripheral surface of a disc-shaped alloy.

As such a cutting wheel, there is one described in Japanese Patent Laid-Open No. 62-48465, which was previously proposed by the present applicant. The cutting edge on the outer circumferential surface is made of an alloy mixed with fine-grained diamonds, so it can easily cut cast iron and greatly extend its service life. be.

Further, in this cutting wheel, there is a tendency that the higher the circumferential speed of the cutting wheel is, the more the energy used for cutting is saved.

[Problem that the invention seeks to solve]

However, the material used for the alloy of conventional cutting wheels is 5KS-5 (JIS G 4
404, alloy tool steel) subjected to the 11 award treatment is common, and this material has the problem of large expansion due to heat.

The thermal expansion coefficient (linear expansion coefficient) β of 5KS-5 is approximately 12 to
13 (X 10-'), and due to the frictional resistance of the cutting blade during cutting or the frictional heat due to the frictional resistance between the cut object and the side surface of the cutting wheel during cutting, for example, the temperature of the alloy near the cutting blade increases. When raised from 20°C to 500°C, the outer circumference of an 8 inch diameter alloy is (8X25.4)xπX (500-20) xβ=
3.68 to 3.98n+ The dimension will increase. In addition, since the temperature rise decreases as the distance from the cutting edge decreases, the elongation rate differs between the outer and inner periphery of the alloy, causing distortion in the alloy.
As a result, the cutting width increases or the frictional resistance on the side surface of the cutting wheel further increases, resulting in poor cutting quality and the need to increase the propulsive force.

Therefore, the frictional resistance of the cutting edge and the side surface of the cutting wheel increases, and if the stress applied to the base metal exceeds the durability of the material, the alloy may crack or break. there were.

This invention was made by focusing on the problems of the prior art, and has developed a cutting wheel for cutting cast iron and castings that has excellent durability by being equipped with an alloy that does not deform even during high-speed cutting. The purpose is to provide.

[Means for solving problems]

Therefore, in the present invention, in a cutting wheel comprising a disc-shaped alloy and a cutting edge provided on the outer peripheral surface of this alloy, the disc-shaped alloy is mixed with 30 to 30% nickel.
It was molded from an Fe--Ni alloy containing 50% by volume and the remainder being entirely or mostly iron.

[Effect]

The Fe-Ni alloy used in the present invention can be made into an alloy with a very small coefficient of thermal expansion by controlling the content of nickel to an appropriate amount. Then, even if the temperature rises due to frictional heat from the cutting edge or the side surface of the cutting wheel during high-speed cutting, the alloy will hardly deform.

Therefore, the cutting width does not increase, so the sharpness does not deteriorate (and the frictional resistance does not further increase, so damage to the alloy can be prevented).

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a front view of a cutting wheel in a first embodiment of the present invention.

That is, cutting is performed using a disk-shaped base metal 2 and a plurality of arc-shaped cutting blades 3 that are continuous at intervals in the circumferential direction on the outer peripheral surface of this base metal 2 and are provided by brazing. A wheel 1 is constructed.

In addition, a plurality of slots 4 penetrating the front and back surfaces are arranged radially at equal intervals in the circumferential direction on the outer periphery of the disc-shaped base metal 2 and are opened on the outer periphery. .

The material constituting the cutting blade 3 is, for example, disclosed in Japanese Patent Application Laid-Open No. 62-4846.
An alloy in which fine grained diamond is mixed, as described in Japanese Patent No. 5, or other known materials can be used.

Amber is used as the Fe-Ni alloy for the base metal 2 in this embodiment, and its components include approximately 35% by volume of nickel, approximately 0.1% by volume of carbon, and approximately 0.0% of manganese. 5% by volume, the balance being iron.

On the other hand, FIG. 2 is a diagram showing the relationship between the coefficient of thermal expansion and the content of nickel. According to this, the thermal expansion coefficient (linear expansion coefficient) β of the amber used in this example is approximately 1 to 2.
(X 10-'), and assuming that the temperature near the cutting edge of an 8-inch diameter alloy increases from, say, 20°C to 500°C due to frictional heat during cutting, its outer circumference is (8x25.4 )xπX (500-20)Xβ-0
, 3 to 0.6 f1 The size only increases.

This degree of dimensional elongation can be sufficiently absorbed by the slot 4 provided on the outer periphery of the base metal 2, so that no distortion or the like occurs in the base metal 2. Therefore, the cutting width does not increase, so the sharpness does not deteriorate, and unless distortion occurs, the frictional resistance does not increase extremely, so the temperature does not rise excessively.

According to experiments conducted by the applicant, when a feeder made of spheroidal graphite cast iron is finished with a cutting wheel equipped with an alloy using 5KS-5, the base metal breaks after 120 tons. However, in the case of the one using amber, there was no damage even after 120 ton finishing treatment, and it was possible to continue using it. Note that the temperature near the cutting edge at that time was about 500°C for 5KS-5 and about 200°C for Amber, based on the coloring of the alloys used.

That is, when the present invention is implemented, the temperature does not rise as much as shown in the above calculation example, and the temperature rises from 20°C to 20°C.
When the temperature rises to 0° C., the outer circumference of the base metal only extends by 0.1 to 0.2 fi under the same conditions as in the above calculation example.

In this example, an Fe-Ni alloy containing about 35% by volume of nickel, so-called Amber, was used, but as shown in Fig. 2, even if the content is about 30 to 50% by volume, The coefficient of thermal expansion remains low. In addition, as shown in the above experimental results, if the thermal expansion coefficient is small, the temperature will not rise much even when used at high speed rotation, so a nickel content of 30 to 50% by volume is sufficient for practical use. .

On the other hand, if a Fe-Ni alloy with a nickel content that is far outside this range is used, the coefficient of thermal expansion will increase as shown in Figure 2, resulting in distortion due to frictional heat during use. occurs, frictional resistance increases, and the alloy becomes easily damaged (resulting in a significant decrease in durability).

FIG. 3 is a front view of a cutting wheel in a second embodiment of the invention.

In this embodiment, the cutting edges provided on the outer peripheral surface of the base metal 2 are continuous in a ring shape in the circumferential direction and are connected by brazing. As mentioned above, since the base metal 2 has small distortion, it is possible to make the cutting edge continuous in a ring shape, and
When the cutting wheel is continuous in a ring shape as in this embodiment, the stress during rotation of the cutting wheel is constant.

〔Effect of the invention〕

As explained above, according to the present invention, the disc-shaped alloy of the cutting wheel is made of an Fe-Ni alloy that has a small coefficient of thermal expansion and contains 30 to 50% by volume of nickel. Almost no distortion occurs.

Therefore, the cutting width does not increase and the frictional resistance does not increase significantly, so large stress is not applied to the alloy, making it difficult for breakage accidents to occur.

Therefore, a cutting wheel using this alloy does not deteriorate in sharpness even when used at high speed, and has the advantage of improved durability.

[Brief explanation of the drawing]

Fig. 1 is a front view of a cutting wheel according to the first embodiment of the present invention, Fig. 2 is a diagram showing the relationship between the coefficient of thermal expansion and the nickel content, and Fig. 3 is a diagram showing the relationship between the coefficient of thermal expansion and the nickel content. FIG. 3 is a front view of the cutting wheel of FIG. 1... Cutting wheel, 2... Base metal, 3...
・Cutting blade.

Claims (2)

[Claims] (1) A cutting wheel comprising a disc-shaped base metal and a cutting blade provided on the outer peripheral surface of the base metal, wherein the disc-shaped base metal contains 30 to 50% by volume of nickel, and Fe in which all or most of the remainder is iron
- A cutting wheel for cutting cast iron castings, characterized in that it is molded from a Ni-based alloy. (2) The cutting wheel for cutting cast iron castings according to claim 1, wherein the Fe-Ni alloy is amber.