JPH06155305A - Manufacture of abrasive grain layer for cutting ferro-concrete - Google Patents

Abstract

PURPOSE:To provide a manufacturing method of an abrasive grain layer for cutting ferro-concrete capable of manufacturing an abrasive grain layer with a long span of life suitable for ferro-concrete cutting. CONSTITUTION:Diamond abrasive grains 4 and cubic system boron nitride abrasive grains 12 are uniformly mixed into a binding material 13 at an inclusion rate respectively in correspondence with a ratio of a sectional area of concrete occupying in a sectional area of ferroconcrete to be a cutting object and in correspondence with a ratio of a sectional area of reinforcing bars occupying in the sectional area of the ferroconcrete, and thereafter, the binding material 13 mixed with the diamond abrasive grains 4 and the cubic system boron nitride abrasive grains 12 is moulded as an abrasive grain layer 8 by sintering or hot press under a powder metallurgy method.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an abrasive grain layer for cutting reinforced concrete.

[0002]

2. Description of the Related Art Conventionally, a grinding tool called a diamond wheel using diamond as an abrasive grain has been known,
It is usually used for cutting concrete, stone materials, asphalt, artificial building materials, etc.

FIGS. 5 to 7 show an example of the above diamond wheel. This type of diamond wheel 1
Is a disk-shaped base metal 3 having a plurality of slots 2 formed in the outer peripheral portion and cut in the radial direction, and abrasive grains formed by containing diamond abrasive grains 4 at the outer edge portion between the slots 2 of the base metal 3. Layer 5 is used, and concrete or the like can be cut by the abrasive grain layer 5 by being attached to a cutting machine (not shown) through a mounting hole 6 opened in the center of the base metal 3 and driven to rotate. It is like this.

[0004]

However, although the diamond wheel 1 as described above is conventionally used for cutting reinforced concrete, the abrasive grain layer 5 of the diamond wheel 1 is used for cutting the reinforcing bar portion. Since the cutting point (grinding point) becomes high in temperature and the diamond abrasive grains 4 are graphitized, the diamond abrasive grains 4 are heavily consumed in the reinforcing bar portion, the life of the abrasive grain layer 5 is shortened, and the cost is increased. was there.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a method for producing an abrasive grain layer for cutting reinforced concrete, which is capable of producing an abrasive grain layer having a long life and suitable for cutting reinforced concrete. I am trying.

[0006]

DISCLOSURE OF THE INVENTION According to the present invention, the ratio of the cross-sectional area of concrete occupying the cross-sectional area of reinforced concrete to be cut with diamond abrasive grains to the ratio of the cross-sectional area of cubic boron nitride abrasive grains to the cross-sectional area of reinforced concrete Uniformly mixed into the binder at a content ratio corresponding to the ratio of the cross-sectional area of each, then the binder mixed with the diamond abrasive grains and cubic boron nitride abrasive grains, sintered by powder metallurgy, or hot press The present invention relates to a method for manufacturing an abrasive grain layer for cutting reinforced concrete, characterized in that the abrasive grain layer is molded as an abrasive grain layer.

[0007]

When the reinforced concrete is cut using the abrasive grain layer produced according to the present invention, the concrete of the surface layer portion of the reinforced concrete is cut by the diamond abrasive grains and the cubic boron nitride abrasive grains of the abrasive grain layer. However, due to the difference in hardness during cutting, the cubic boron nitride abrasive grains wear out somewhat faster than the diamond abrasive grains, and the diamond abrasive grains that are advantageous in terms of hardness continue to wear relatively slightly. The remaining diamond abrasive grains continue to cut the concrete even after the cubic boron nitride abrasive grains are consumed.

[0008] Next, when it reaches the rebar portion inside the reinforced concrete, the cutting point (grinding point) becomes high in temperature and the diamond abrasive grains are graphitized to be consumed, but at this time, the binder of the abrasive grain layer is also scraped. As a result, new cubic boron nitride abrasive grains are consumed and the cubic boron nitride abrasive grains are projected, and the reinforcing rod is cut by the cubic boron nitride abrasive grains.

That is, although the cubic boron nitride abrasive grains are inferior in hardness to diamond abrasive grains, the degree of wear at high temperature is lower than that of diamond abrasive grains, so that the conventional abrasive grain layer containing only diamond abrasive grains is used. The cutting of the reinforcing bar is continued while the progress of wear is slower.

When the cutting of the reinforcing bar portion is completed and the concrete portion is reached again, new diamond abrasive grains are projected due to the consumption of the binder as described above, and the same concrete cutting as described above is performed.

[0011]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows one embodiment of the present invention, and illustrates the case of an abrasive grain layer 8 applied to a straight wheel 7 of the same type as the conventional example of FIGS. 5 to 7 described above. .

In manufacturing the abrasive grain layer 8, FIG.
The cross-sectional area As of the concrete 10 occupying the cross-sectional area of the reinforced concrete 9 to be cut and the cross-sectional area Ac of the rebar 11 occupying the cross-sectional area of the reinforced concrete 9 as shown in FIG.
And the cubic boron nitride abrasive grains 12 (CB) in proportion to the cross-sectional area As of the concrete.
N abrasive grains) are uniformly mixed in the binder 13 at a content ratio corresponding to the ratio of the cross-sectional area Ac of the reinforcing bar 11.

That is, when the total amount of the diamond abrasive grains 4 and the cubic boron nitride abrasive grains 12 is Q, the amount Qs of the diamond abrasive grains 4 is obtained by the following mathematical formula.

[0015]

[Equation 1]

Further, the amount Qc of the cubic boron nitride abrasive grains 12 is obtained by the following mathematical formula.

[0017]

[Equation 2]

The binder 13 is bronze,
The total amount Q of the diamond abrasive grains 4 and the cubic boron nitride abrasive grains 12 is determined by using a metal powder containing a metal such as cobalt or tungsten as a main component, and the diamond abrasive grains 4 and the cubic boron nitride abrasive grains 12 and the binder are The content rate is 25 vol% with respect to the total sum of.

Next, the bonding material 13 in which the diamond abrasive grains 4 and the cubic boron nitride abrasive grains 12 are mixed is formed into an abrasive grain layer 8 by sintering by powder metallurgy or hot pressing.

When the abrasive grain layer 8 formed as described above is joined to the outer edge portion of the base metal 3 by brazing or laser welding to cut the reinforced concrete 9, the reinforced concrete 9 is cut.
The concrete 10 of the surface layer portion is cut by the diamond abrasive grains 4 and the cubic boron nitride abrasive grains 12 of the abrasive grain layer 8.

Here, both the diamond abrasive grains 4 and the cubic boron nitride abrasive grains 12 are involved in the cutting of the concrete 10, but the cubic boron nitride abrasive grains due to the hardness difference as the cutting is continued. No. 12 wears out a little faster than the diamond abrasive grains 4, and the hardness-favorable diamond abrasive grains 4 remain while being relatively slightly consumed, and after the cubic boron nitride abrasive grains 12 are consumed. Also, the cutting of the concrete 10 is continued by the remaining diamond abrasive grains 4.

Next, when reaching the portion of the reinforcing bar 11 inside the reinforced concrete 9, the cutting point (grinding point) becomes high in temperature and the diamond abrasive grains 4 are graphitized to be consumed, but at this time, the abrasive grain layer 8 is bonded. The material 13 is also consumed by chips and the like, and new cubic boron nitride abrasive grains 12 are projected,
Reinforcing bars 11 are cut by the cubic boron nitride abrasive grains 12.

That is, although the cubic boron nitride abrasive grains 12 are inferior to the diamond abrasive grains 4 in hardness, the degree of wear at a high temperature is lower than that of the diamond abrasive grains 4, so that the conventional diamond abrasive grains containing only the diamond abrasive grains 4 are used. The cutting of the reinforcing bar 11 is continued in a state in which the progress of wear is slower than that of the abrasive grain layer 5.

Further, when the cutting of the reinforcing bar 11 is completed and the concrete 10 is reached again, new diamond abrasive grains 4 are projected due to the consumption of the binder 13 described above, and the cutting of the concrete 10 similar to the above is performed. Done.

As described above, according to the abrasive grain layer 8 manufactured according to this embodiment, as compared with the conventional abrasive grain layer 5 containing only the diamond abrasive grains 4, when the reinforced concrete 9 is cut. The life of the abrasive layer is significantly extended.

Therefore, according to this embodiment, the abrasive grain layer 8 having a long life and suitable for cutting the reinforced concrete 9 can be manufactured, and the cost can be significantly reduced as compared with the conventional case.

In the illustrated example, the abrasive grain layer 8 manufactured according to the present invention is applied to the straight wheel 7. However, as shown in FIG. 3, the abrasive grain layer 8 may be applied to the band saw 14 as well. Alternatively, as a matter of course, it may be applied as the abrasive grain layer 8 of the wire saw 15 as shown in FIG.

When the reinforcing bars 11 of the reinforced concrete 9 to be cut are unevenly arranged, for example, the reinforcing bars 11 are often arranged on the front side in the cutting direction and small on the rear side. In such a case, the reinforced concrete 9 is considered to be divided into two sections, the front side and the back side in the cutting direction, and the ratios of the respective cross-sectional areas of the concrete 10 and the rebar 11 occupying the cross-sectional area of the reinforced concrete 9 in each section are respectively calculated. Then, the diamond abrasive grains 4 and the cubic boron nitride abrasive grains 12 are uniformly mixed with the binder 13 according to the ratio of the respective compartments, and the mixture having different content ratios is layered and fired by the powder metallurgy method. The abrasive grain layer 8 is integrally formed by binding or hot pressing, and the content ratio of the cubic boron nitride abrasive grains 12 is relatively increased on the outer side of the abrasive grain layer 8 which is the cutting start side, and the cutting end side is formed. Inner content of the diamond abrasive grains 4 may be relatively increased in made.

The method for producing the abrasive grain layer for cutting reinforced concrete of the present invention is not limited to the above-mentioned embodiment, and various modifications can be made without departing from the scope of the present invention. Is.

[0030]

According to the method for producing an abrasive grain layer for cutting reinforced concrete of the present invention described above, it is possible to produce an abrasive grain layer having a long life, which is suitable for cutting reinforced concrete. The excellent effect of being able to reduce it can be produced.

[Brief description of drawings]

FIG. 1 is a schematic view showing an example of an abrasive grain layer produced according to an example of the present invention.

FIG. 2 is a cross-sectional view showing an example of reinforced concrete.

FIG. 3 is a schematic view showing an example in which an abrasive grain layer manufactured according to an embodiment of the present invention is applied to a band saw.

FIG. 4 is a schematic view showing an example in which an abrasive grain layer manufactured according to an embodiment of the present invention is applied to a wire saw.

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

6 is a view in the direction of arrow VI-VI of FIG.

FIG. 7 is an enlarged schematic view of a VII portion in FIG.

[Explanation of symbols]

 4 Diamond Abrasive Grain 8 Abrasive Grain Layer 9 Reinforced Concrete 10 Concrete 11 Reinforcing Bar 12 Cubic Boron Nitride Abrasive Grain 13 Binder

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Keinosuke Tokushige 3-15-1, Toyosu, Koto-ku, Tokyo Ishikawajima Harima Heavy Industries Co., Ltd. Toji Technical Center (72) Inventor Yoshikazu Awana Tamagawa Garden, Setagaya-ku, Tokyo Chofu 1-15-12 Nicotec Co., Ltd. (72) Inventor Masahide Fuchu 45 Tomoe Bessho-cho, Miki City, Hyogo Prefecture Nicotec Co., Ltd.

Claims (1)

[Claims] 1. Corresponding to the ratio of the cross-sectional area of concrete to the cross-sectional area of the reinforced concrete to be cut with diamond abrasive grains, and to the ratio of the cross-sectional area of the reinforcing bar to the cross-sectional area of the reinforced concrete with cubic boron nitride abrasive grains. The mixture is uniformly mixed with the binder in the content ratio, and then the binder mixed with the diamond abrasive grains and the cubic boron nitride abrasive grains is formed into an abrasive grain layer by sintering by powder metallurgy or by hot pressing. A method for producing an abrasive grain layer for cutting reinforced concrete, which comprises: