WO1997012713A1

WO1997012713A1 - Diamond tool for cutting reinforced structure and method of cutting reinforced structure

Info

Publication number: WO1997012713A1
Application number: PCT/JP1996/002842
Authority: WO
Inventors: Akifumi Hoshino; Taku Murakami
Original assignee: Komatsu Ltd.
Priority date: 1995-10-03
Filing date: 1996-09-30
Publication date: 1997-04-10
Also published as: JPH09103916A

Abstract

A diamond tool for cutting a reinforced structure and a method of cutting a reinforced structure, wherein the consumption of diamond abrasive is reduced, so that a life of the diamond tool is extended. An abrasive layer (1) of a diamond tool (10) for cutting a reinforced structure comprises diamond particles (2) and graphite particles (3) which are bonded together with binder (4). A preferable graphite content in the abrasive layer is 20 to 30 volume percentage. Also, a method of cutting a reinforced structure comprises cutting a reinforced structure (70) while feeding a cutting liquid containing graphite particles near the contact area between the reinforced structure (70) and a diamond tool (20). A preferable graphite content in the cutting liquid is 2 to 20 percent by weight.

Description

Description Diamond drill tool for cutting reinforced structures and cutting method

The present invention relates to a diamond drill for cutting a reinforced structure suitable for cutting a composite structure of an iron-based member and a hard member such as a concrete, and a cutting method. Background technology

Conventionally, diamond tools have been used for cutting and grinding high-hardness inorganic members such as concrete and glass. Also, when cutting a composite structure of an iron-based member and a high-hardness member, such as a reinforced concrete, a diamond tool is frequently used due to its highest hardness.

As a diamond tool, as shown in FIG. 6, beads 53 embedded diamond abrasive grains 51 with a binder 52 such as nickel or cobalt are fixed to the outer periphery of a metal sleeve 55 and a metal There is known a wire saw 150 in which a number of sleeves 55 pass through the outer periphery of the wire 57 at predetermined intervals. The wire saw 50 has a groove 59 formed between the bead 53 and the capacitance sensor 56. When cutting a reinforcing bar structure using the wire saw 50, a cutting fluid, which is also a coolant, is supplied to cut the reinforcing bar and the concrete.

However, the diamond abrasive grains 51 in contact with the non-cut body become hot due to the cutting resistance and friction during cutting. In particular, when the exothermic temperature is equal to or higher than the A, transformation point of the steel as the reinforcing steel, carbon from the diamond abrasive grains 51 diffuses into the steel, and the amount of diffusion rapidly increases as the exothermic temperature rises. For this reason, there is a problem that the consumption of the diamond abrasive grains 51 is increased and the life of the gasoline 50 is shortened. In order to suppress the heat generation temperature, it is necessary to reduce the cutting speed, but there is a problem that the cutting time is significantly increased. As another diamond tool, as shown in FIG. 7, beads 53 and cutting tools 61 are used. Alternately provided wire-to-60 are known (for example, Japanese Utility Model No. 1-11019). The cutting tool 61 embeds ceramics-based hard particles 63 such as tungsten carbide or boron nitride using a synthetic resin as a binder 65. As shown in FIG. 8, the wire saw 60 is wound around the outer periphery of a reinforced structure 70 that is a non-cut body, and is rotated by a driving device 69 while being cooled by the cutting fluid from the nozzle 67. Then cut. At the time of this cutting, tension is generated in the wire saw 60 by pulling the driving device 69 with the tension wire 71 fixing one end to the anchor 73. As described above, since the beads 53 mainly cut the concrete and the carbide particles 65 mainly cut the reinforcing bar, the consumption of the diamond abrasive grains 51 is reduced.

However, in the case of cutting with a wire saw 60 including the beads 53 and the cutting tool 61, unsuitable cutting, that is, cutting of reinforcing steel by diamond abrasive grains 51 and ceramic-based carbide particles 65. Cutting concrete is inevitable. Therefore, since the wear and breakage due to these unsuitable cuttings are not small, the life of the wire saw 60 is insufficient. Also, the wear of the diamond abrasive grains 51 and the carbide particles 65 differs depending on the difference in the reinforcement ratio (the ratio of the reinforcing bars in the reinforcing bar structure 70), so that the life of the wire saw 60 is reduced by beads. Depends on the shorter wear time of 5 3 or cutting tool 6 1.

Also, a tool for forming an amorphous carbon layer on the surface of diamond abrasive grains is known (for example, Japanese Patent Application Laid-Open No. Hei 4-190001, and Japanese Patent Application Laid-Open No. Hei 6-163606). . According to this tool, good wear resistance is achieved in steel cutting by reducing the thickness of the high-hardness amorphous carbon layer from the submicron to several tens of meters.

However, when the amorphous carbon layer is thin, the consumption of carbon is generated at an early stage, and diamond rebar cutting is mainly used, and the tool life is insufficient. On the other hand, when the amorphous carbon layer is thick, the carbon layer is likely to be separated due to cutting and cutting of the reinforcing bar and the concrete, so that the life is similarly insufficient. Disclosure of the invention

The present invention has been made to solve the problems of the related art, It is an object of the present invention to provide a diamond tool for cutting a reinforced structure and a cutting method capable of improving the service life and obtaining appropriate workability when cutting a composite structure made of a material and a hard member such as a concrete. Aim.

The diamond drill for cutting a reinforced structure according to the present invention is a diamond drill for cutting a reinforced structure having an abrasive layer formed by bonding diamond abrasive grains with a binder, wherein the abrasive layer has a diamond abrasive. It is an abrasive layer formed by bonding particles and graphite particles with a binder. In addition, the graphite particles contain fi in the abrasive layer.

It is preferably from 2 to 30% by volume.

According to such a configuration, the diamond abrasive grains react with the rebar, and solid-dissolve and diffuse into the rebar, because the surface temperature of the diamond abrasive grains increases by cutting the non-cutting rebar structure. And However, at the time of cutting, the graphite particles fall off, chip, or become abrasion powder from the abrasive grain layer, and are supplied to the contact portion between the reinforced structure and the diamond abrasive grains being cut. The graphite particles having low hardness form a thin film at the contact portion, thereby reducing direct contact between the diamond abrasive grains and the reinforcing steel. Therefore, the reaction between the diamond abrasive grains and the reinforcing steel is reduced due to the presence of the graphite thin film which is hardly chemically reacted with the reinforcing steel, so that the consumption of the diamond abrasive grains is reduced. This reduction in wear makes it possible to extend the life of diamond tools. In addition, by setting the graphite particle content to a predetermined amount, the life can be improved and the strength of the abrasive layer can be appropriately adjusted, so that work can be performed at a useful cutting speed.

Next, a method for cutting a reinforcing bar structure according to the present invention is a method for cutting a reinforcing bar structure that cuts a reinforcing bar structure by supplying a cutting fluid near a contact portion between the reinforcing bar structure and the diamond tool. It is characterized in that the supplied cutting fluid contains graphite particles. Further, it is preferable that the content of the graphite particles is 2 to 20 times S% with respect to the supplied cutting fluid.

According to such a configuration, the graphite particles in the cutting fluid are supplied to the contact portion between the reinforced structure and the diamond abrasive grains. By this supply, an effect similar to that of the above-described diamond tool is obtained. By setting the content of graphite in the cutting fluid to a predetermined amount, It is possible to work at an appropriate cutting speed. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a sectional view of a wire saw according to a first embodiment of the present invention,

FIG. 2 is an explanatory diagram of the cutting device according to the first embodiment,

FIG. 3 is a sectional view of a jack according to a second embodiment of the present invention,

FIG.4A is a front view of a blade according to a fourth embodiment of the present invention,

FIG. 4B is a view taken along arrow 4 B— 4 B in FIG. 4A.

Fig. 5 is an explanatory diagram of the cutting test situation of the blade according to the fourth embodiment,

Figure 6 is a cross-sectional view of a conventional wire saw.

Fig. 7 is a sectional view of another conventional wire saw.

FIG. 8 is an explanatory view of a conventional cutting apparatus.

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 shows a wire saw 10 which is an example of the diamond dressing tool of the first embodiment. In the wire saw 10, a large number of beads 8 are inserted at predetermined intervals around the outer periphery of the wire 57, and a rubber spacer 6 is fixed between the metal sleeves 5, 5. The beads 8 are composed of a metal sleeve 5 and an abrasive layer 1 fixed to the outer periphery of the metal sleeve 5. The abrasive layer 1 is embedded with a binder 4 in which diamond abrasive particles 2 and graphite particles 3 are dispersed. The groove 7 formed between the abrasive grains 1 and 1 serves as a passage for supplying the cutting fluid and also serves as a passage for discharging the cutting powder.

The S content of the graphite particles 3 in the abrasive layer 1 may be 2 to 30% by volume. However, from the viewpoints of more appropriate strength of the abrasive layer 1 and reduction of consumption of the diamond abrasive particles 2, 5-1 5% by volume is preferred. Further, the graphite particles 3 are mixed with the diamond abrasive grains 2 and the mixing agent 4 and the like and dispersed in the binder 4 before the formation of the abrasive layer 1. Therefore, the starting material of the graphite particles 3 has a different degree of crushing depending on the mixing conditions, and has a general size. Graphite powder can be used. The graphite powder size is preferably about submicron to about 100 m, and more preferably about 1 to 40 m in consideration of the dispersibility, the strength of the abrasive layer 1 and the like. The binder 4 may be a general cobalt-based binder, and a carbide such as tungsten carbide and a metal powder such as copper and nickel may be added as necessary.

FIG. 2 shows a cutting device 11 to which a wire saw 10 is applied. The cutting device 11 includes a driving device 12, a tension holding device 14, a guide pulley 15, and a cutting fluid supply device 16. I have. The wire saw 10 is mounted on the drive device 1 2 and the tension holding device

The drive unit 12 is pulled through the tension wire 13 by 14 force. As a result, the wire saw 10 wound around the outer periphery of the reinforced structure 70 is driven to rotate by the driving device 12 under a predetermined tension, and performs a cutting operation of the reinforced structure 70. During this cutting operation, a general water-soluble cutting fluid is supplied from the nozzle 17 of the cutting fluid supply device 16 to the vicinity of the contact portion between the reinforcing bar structure 70 and the wire saw 10 to cool the wire saw 10. are doing.

In addition, as the cutting operation progresses, the uncut portion 70a shrinks, but the guide pulley 15 supports stable cutting of the wire saw 10 and the wire saw 10 is opened at the end of cutting. Unstable deformation due to is suppressed. When the tension of the tension wire 13 becomes lower than the set value, such as at the end of cutting, the tension holding device 14

The tension automatically? It has a safety circuit for T.

A first cutting example according to the configuration of the first embodiment will be described. The main specifications of the abrasive layer 1 are as follows: the particle size of the diamond abrasive particles 2: 40/50, the concentration: 20, the average particle size of the graphite particles 3: about 3 / m, the content of the graphite particles 3: 6% by volume, Mixture 4: Cobalt-based binder. The wire saw 10 has a bead 8 outer diameter: 10 mm, a bead 8 length: 6 mm, and a bead 8 pitch: 25 mm. The main cutting conditions are a speed of the wire saw 10: 25 mZ sec, a tension of the tension wire 13: 70 kgf, and a cutting fluid supply amount: 10 liter / min. The non-cutting reinforced structure 70 is a reinforced concrete block with a reinforcement ratio of 3%. Cutting result, wire saw 10 per 1 m The cutting life was about 0.7 m ² m, assuming the cutting area as the cutting area of the reinforcing steel structure 70 to be cut.

Next, a second embodiment according to the present invention will be described.

FIG. 3 shows a wire saw 20 of the present embodiment. The abrasive 1a of the wire saw 20 has a configuration in which diamond abrasive grains are dispersed and embedded in a binder 4 and does not contain graphite particles 3 (see FIG. 1). And different. The cutting device to which the wire saw 20 is applied is almost the same as the cutting device 11 of the first embodiment shown in FIG. 2, but the grinding fluid supplied from the cutting fluid supply device 16 is different.

That is, the grinding fluid of this embodiment contains graphite particles in the water-soluble cutting fluid. The content of graphite particles in the cutting fluid and the supply of the graphite particle-containing cutting fluid vary depending on cutting conditions and the like. For example, when the graphite particle content is 2 to 20% by weight and the supply amount is 5 to 30% Little / min. At the time of cutting, the graphite-containing cutting fluid is supplied from the nozzle 17 of the cutting fluid supply device 16 to the vicinity of a contact portion between the reinforced structure 70 and the wire saw 10. The graphite particles have the same function as the graphite particles 3 of the first embodiment when cut, and the graphite powder having the above size is used.

A second cutting example in the second embodiment will be described. The main specifications of the abrasive layer 1a are the same as those of the abrasive layer 1 of the first cutting example except that the graphite layer 3 is not contained. The outer diameter of the beads 8 of the wire saw 20 is the same as that of the wire saw 10 of the first cutting example. The main cutting conditions and the non-cutting body are the same as in the first cutting example, except that the cutting fluid contains 10% by weight of graphite particles having an average particle size of 3 m. As a result of the above cutting, the cutting life of the wire saw 20 was about 0.8 m ² / m.

The first and second embodiments are examples in which the wire saw 10 or the cutting fluid contains the graphite particles 3, but as comparative examples, cutting examples in which neither of them contains the graphite particles will be described. That is, the cutting life of the wire saw 20 was about 0.3 m ² Zm as a result of cutting it using a grinding fluid and a wire saw 20 containing no graphite particles in the same manner as in the first cutting example. It has been found that the present invention containing particles has excellent properties. Next, a third embodiment according to the present invention will be described. The present embodiment is an example in which the wire saw 10 of the first embodiment containing graphite particles 3 is combined with the cutting fluid of the second embodiment containing graphite particles. In the third cutting example having such a configuration, the specifications, cutting conditions and cutting conditions of the first cutting example are the same except that the cutting fluid contains 10% by weight of graphite particles having an average particle diameter of 3 m (same as the second cutting example). Same as the uncut body. As a result of the cutting, the cutting life of the wire saw 110 was about 0.9 m ² Zm.

FIG. 4A shows a blade 30 serving as a diamond tool of the fourth embodiment. A large number of segments 8 a are fixed to the outer periphery of a disk-shaped metal base 31. In this segment 8a, as shown in FIG. 4B, an abrasive layer 1 in which diamond abrasive particles 2 and graphite particles 3 are bonded with a binder 4 is fixed on a metal member 32. . The content of the graphite particles 3 in the abrasive layer 1 is the same as that of the wire saw 10 of the first embodiment.

FIG. 5 shows a cutting test condition using a grinder 35, in which a blade 30 having an outer diameter of 14 inches is used. The main specifications of the abrasive layer 1 are as follows: the particle size of the diamond abrasive particles 2: 50 to 50, the degree of concentration: 30, the average particle size of the graphite particles 3: about 3 m, the content of the graphite particles 3: 8 Fertility, Binder 4: Cobalt-based binder. The main cutting conditions are: peripheral speed of blade 30: 40 m / sec, feed speed: 1.5 mZmin, depth of cut: 10 cm / path, cutting fluid: general water-soluble cutting fluid, cutting Liquid supply amount: 15 liter min. The reinforcement arrangement ratio of the non-cutting body 70 is 2%. As a comparative example, a blade similar to blade 30 was used except that graphite particles 3 were not contained.

Cutting test results, the blade 3 0, the cutting area of the reinforcement structure 7 0 in the thickness direction 1 mm consumable per abrasive grain layer 1, i.e., the cutting life, though was about teeth 2 m ² ZMM On the other hand, in the blade of the comparative example, it was about 0.5 m ² / mm, and also in this example, the excellent action of the graphite particles was recognized. In addition, the wear of the abrasive layer 1 of each segment 8a is almost the same, which indicates that the blade 30 performance is effectively utilized. Industrial applicability The present invention reduces the consumption of diamond abrasive grains, improves the tool life, and enables a work at a useful cutting speed to obtain a suitable workability. It is useful as a cutting method.

Claims

The scope of the claims

1. In a diamond drill for cutting a reinforced structure having an abrasive layer formed by bonding diamond abrasive grains with a binder,

The reinforcing grain structure is characterized in that the abrasive grain layer is an abrasive grain layer (1) obtained by binding the diamond abrasive grains (2) and the graphite particles (3) with the binder (4). Diamond cutting tool for cutting.

2. The diamond door for cutting a reinforced structure according to claim 1, wherein the content of the graphite particles (3) is 2 to 30% by volume with respect to the abrasive layer (1). Utensils.

3. In the method of cutting a reinforcing bar structure for cutting the reinforcing bar structure by supplying a cutting fluid near a contact portion between the reinforcing bar structure and the diamond tool,

The method for cutting a reinforcing steel structure, wherein the cutting fluid supplied includes graphite particles.

4. The method for cutting a reinforced structure according to claim 3, wherein the content of the graphite particles is 2 to 20% by weight with respect to the supplied cutting fluid.