JPH11156726A - Cutting tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cutting tool with sufficiently high strength, and excellent processability in a rotary tool using inorganic fibers. SOLUTION: In a cutting tool comprising inorganic fiber cloth impregnated with resin binding agent formed into a disc shape, the inorganic fiber cloth is formed of sieve opening cloth, and furthermore, a tool 1 contains abrasive grain. This inorganic fiber cloth is either of alumina fiber cloth, alumina silica fiber cloth, silica fiber cloth, silicon carbide fiber cloth, carbon fiber cloth or glass fiber cloth. Besides, abrasive grain is composed of diamond, silicon carbide, alumina, or of CBN.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a rotary tool suitable for cutting. More specifically, the present invention relates to a cutting tool excellent in smoothness of a cut surface of a workpiece, low in cutting resistance, low in heat generation, and excellent in safety without breakage of the tool during cutting work.

[0002]

2. Description of the Related Art Conventionally, as a tool of this type, as disclosed in Japanese Patent Publication No. 102504/1990, a plurality of fiber layers in which inorganic fibers such as alumina fibers are aligned in one direction are laminated, and A resin binder such as a thermosetting resin is impregnated and cured to form a dense disk body, and the fiber ends of the inorganic fibers are exposed as processing elements on the outer peripheral surface of the disk body,
There is known a tool capable of performing processing at the fiber end.

[0003]

In the case of the above-mentioned conventional tool, since it is necessary to form the entire tool densely, a fiber cloth cannot be used, and a plurality of fiber layers aligned in one direction are laminated. Needed. Therefore, there is a problem such as delamination between fiber layers, and there is a disadvantage that a rotary tool having sufficient strength cannot be formed, and this type of rotary tool using inorganic fibers as a processing element has not been put to practical use at present. is there. In addition, since the fiber end acting as a processing element appears only on the circumferential surface of the disk, there is an inconvenience that the production of the tool is simple, but only extremely insufficient processing can be performed in actual cutting and cutting. . That is, to explain this in detail, important factors in a so-called cutting grindstone for cutting include reduction in resistance at the time of cutting and reduction in surface roughness of the end face of the object to be cut. Both of these are related to the state of the side surface of the cutting grindstone. On the side surface of the cutting grindstone having no cutting ability, the cutting resistance increases due to friction with the object to be cut, and in extreme cases, the cutting direction shifts more and more. Will be. Further, the end face of the object to be cut is also burned by the frictional heat. To compensate for these shortcomings, for example,
In a diamond electrodeposition cutting whetstone or the like, electrodeposition is also performed on the side surface side of the cutting edge to make the cutting edge portion thicker than the metal portion. If this is not enough, diamond is also electrodeposited on the side surface at a constant width in the circumferential direction so that the side surface of the metal reaching the cutting edge has polishing properties.
Also, in the case of vitrified cutting grindstones that cannot make only the cutting edge thicker, the cutting surface and the side surface are made of the same material, so that the side surface can also be cut, reducing cutting resistance and improving the finish of the end surface of the object to be cut. I have. That is, in the cutting whetstone, the sharpness of the side surface greatly affects not only the cutting resistance but also the finish of the end surface of the object to be cut. Unfortunately, when the conventionally known unidirectionally aligned fiber layers are superimposed or the fiber cloth is simply laminated, when used as a grinding stone for cutting, the sides of the fibers are It was not possible to expect a cutting or polishing effect just by exposing. Therefore, an object of the present invention is to solve the above-mentioned disadvantages of the prior art, and to provide a rotary tool using inorganic fibers, which has a sufficient strength and is excellent in workability.

[0004]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies in order to achieve the above-mentioned object. We found that by using an inorganic fiber cloth with openings as the elements and including abrasive grains in the cutting tool thus porous, a cutting tool with extremely excellent strength and good workability can be obtained. did. The cutting tool of the present invention is based on such knowledge, and in a cutting tool formed by impregnating and hardening a resin binder into an inorganic fiber cloth to form a disk, the inorganic fiber cloth is constituted by an aperture cloth, In addition, the tool contains abrasive grains. The cutting tool according to claim 2 is characterized in that the opening ratio of the opening cloth is 10 to 50%. Further, the cutting tool according to claim 3 is characterized in that the opening ratio of the opening cloth is 20 to 40%. Further, in the cutting tool according to claim 4, the inorganic fiber cloth is any one of an alumina fiber cloth, an alumina-silica fiber cloth, a silica fiber cloth, a silicon carbide fiber cloth, a carbon fiber cloth, and a glass fiber cloth. It is characterized by the following. A cutting tool according to a fifth aspect is characterized in that the ceramic fiber cloth is a plain weave, a twill weave, or a triaxial weave. Also,
The cutting tool according to claim 6 is characterized in that the resin binder is a thermosetting resin such as an epoxy resin or a phenol resin. The cutting tool according to claim 7 is characterized in that the abrasive grains are diamond, silicon carbide, alumina, or CBN.

As described above, according to the present invention, an inorganic fiber cloth having a large opening ratio is used, and a cutting tool made porous by such an inorganic fiber cloth having a large opening ratio contains abrasive grains. The fiber cloth structure provides sufficient strength and excellent safety, as well as the cutting properties on the side of the disk body by the abrasive grains.In addition, both the cutting edge of the inorganic fiber and the abrasive grains on the circumferential surface of the disk body Work together to obtain a very good cut surface of the workpiece. In addition, the use of inorganic fiber cloth with a large opening ratio has a heat radiation effect,
Friction heat during processing can be suppressed. Due to these actions, the workability becomes very excellent.

As the inorganic fibers constituting the inorganic fiber cloth, alumina fibers, alumina / silica fibers, silica fibers, silicon carbide fibers, carbon fibers, glass fibers and the like are used.

[0007] The inorganic fiber cloth may be formed into a disk by impregnating and curing a resin binder containing abrasive grains after laminating one or more sheets as necessary, or may include abrasive grains one by one. A plurality of fibers impregnated with a resin binder may be laminated and cured to form a disc body on which a plurality of fiber cloths are laminated. Also, first impregnate the inorganic fiber cloth with a resin binder containing no abrasive grains,
Thereafter, abrasive grains may be attached to the outer surface thereof, and the prepreg may be laminated to form a cutting tool containing abrasive grains.

[0008] The weave of the cloth is plain weave, twill weave,
A biaxial weave cloth such as a satin weave or a triaxial weave cloth is optional.

The opening ratio of the inorganic fiber cloth should be about 10 to 50%, preferably about 20 to 40%, in consideration of the balance between the heat radiation effect and the mechanical strength, the content of abrasive grains, and the like. preferable.

It is preferable to use diamond, silicon carbide, alumina, CBN, or the like as the abrasive.

The resin binder impregnated in the inorganic fiber cloth is not particularly limited, but is preferably a thermosetting resin such as an epoxy resin and a phenol resin.
When heat resistance is required, use of a heat-resistant resin such as polyimide or polyamide resin is preferable.

The fiber content of the cutting tool is preferably in the range of 50% by weight to 80% by weight. If the amount is less than 50% by weight, the cutting ability is reduced. If the amount is more than 80% by weight, there is a risk of delamination between fiber cloths during cutting.
For safety, the range of 70-80% by weight is optimal. Further, the abrasive is desirably in the range of 5 to 30% by weight. this is,
If the abrasive is less than 5% by weight, the performance as a cutting tool drops,
If it exceeds 30% by weight, the adhesion rate to the inorganic fiber cloth is so poor that it cannot be practically used.

Next, an embodiment of the cutting tool of the present invention will be described with reference to the drawings. (Example 1) 72% by weight of alumina component, 28 of silica component
Alumina fiber strand having 10% by weight of gamma-alumina as a main crystal (10 μm, 1000 filaments)
Is cut into 28 cm ceramic fiber cloth (280 g / cm ² ) having an opening ratio of about 28%, and epoxy resin (Epicoat 828: 152)
= 3: 2, manufactured by Yuka Shell Epoxy Co., Ltd., using boron trifluoride monoethylamine as a curing agent and an accelerator in a resin amount of 3
%, And imidazole 0.7%, and methyl ethyl ketone was adjusted to 35% of the total resin amount. ) Was impregnated with a roller. Three impregnated cloths were prepared, and the prepreg of the triaxial woven cloth obtained by drying at 120 ° C. for 18 minutes with a hot air drier was transferred to a vessel containing alumina abrasive grains, 240th, and alumina abrasive grains were transferred. Was almost uniformly adhered to both surfaces of each prepreg. Three of these are laminated and hot pressed at 165 ° C., pressure 20 kgf / cm ² , time 9
Forming was performed under the condition of 0 minutes, and after gradually cooling to around room temperature, this was taken out to obtain a 0.8 mm thick FRP molded plate. The outer diameter of this molded plate is 120 mm and the inner diameter is 30 mm at the center.
Then, a cutting tool made of a reinforced resin of a triaxial weave cloth of alumina fiber containing abrasive grains was prepared by cutting into a donut shape having an opening.

Observation of the cutting tool of the present invention revealed that abrasive grains were interposed on voids on the cloth and on the surface, and the ratio of the abrasive grains in the cutting tool was about 20 wt.
%, And the porosity was about 12 vol%. FIG. 1 is a plan view schematically showing a cutting tool 1 according to the present embodiment, in which 1a is a ceramic fiber, 1b is an abrasive grain, 1c is a void, and the abrasive grain 1b is other than the void 1c. Was distributed evenly in the places.

Next, the obtained cutting tool is attached to a rotating part of an electric cutting machine, and a round bar (φ8 mm) of spheroidized graphite cast iron is cooled to 10 mm / at a rotation speed of 1750 rpm while cooling with water.
min. The cutting test was performed at the speed shown in Table 1.
It was shown to. As Comparative Example 1, the inorganic fiber cloth in Example 1 was replaced with a normal clogged alumina cloth (having a basis weight of 3).
50 g / m ² ) without abrasive grains and as Comparative Example 2, a commercially available diamond wheel (S
The same test was carried out using D230N75BW6 (manufactured by Noritake Company: 96 mm outside diameter, 30 mm inside diameter, 0.7 mm thickness), and the results are also shown in Table 1.

[0016]

[Table 1]

In Table 1, the condition of the cut surface was evaluated as follows. A: Good. The cross-sectional structure can be clearly confirmed. B: Almost good. The surface is slightly rough. C: The cross-sectional state is rough and the structure is unclear. In addition, the wear rate obtained by the following equation is shown. Wear rate (%) = {outer diameter before cutting (mm)-outer diameter after cutting (mm)} / outer diameter before cutting (mm) x 100

(Example 2) A cutting tool was obtained under the same conditions as in Example 1 except that the abrasive was changed to silicon carbide abrasive and 220 grit.

Observation of the obtained cutting tool revealed that the porosity was 12 vol% and the ratio of abrasive grains was about 18 wt%.

With this tool, as in the case of the first embodiment, SUS30
A cutting test was performed on the four pipes (φ80 mm, thickness 0.3 mm), and the results are shown in Table 2. Further, as Comparative Example 3, an ordinary alumina cloth (with a basis weight of 350 g) was used.
/ M ² ), a cutting tool containing silicon carbide-based abrasive grains (220 count) was prepared in the same manner as in Example 2, and the same cutting test was performed. The results are shown in Table 2. Was.
Table 2 also shows the results of a cutting test using the diamond disk of Comparative Example 2.

[0021]

[Table 2]

As is clear from Tables 1 and 2, it can be confirmed that the cutting tool of the embodiment has a smooth cut surface of the workpiece, a small maximum load current value and a small wear rate of the cutting tool. Was.

[0023]

As described above, according to the present invention, in a cutting tool using an inorganic fiber cloth, a cutting tool which has sufficient strength, is excellent in smoothness of a workpiece, and is extremely excellent in workability. Is obtained.

[Brief description of the drawings]

FIG. 1 is a plan view of a cutting tool according to the present invention.

FIG. 2 is an enlarged schematic view of a portion A in FIG.

[Explanation of symbols]

 1 cutting tool 1a ceramic fiber 1b abrasive grain 1c void

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Norihito Katsuoka 2, 3585 Minamiminowa-mura, Kamiina-gun, Nagano Prefecture

Claims (7)

[Claims] 1. A cutting tool formed by impregnating and hardening a resin binder into an inorganic fiber cloth to form a disk, wherein the inorganic fiber cloth is constituted by a mesh cloth, and the tool contains abrasive grains. A cutting tool characterized by being cut. 2. The aperture ratio of the aperture cloth is 10 to 5
The cutting tool according to claim 1, wherein the cutting tool is 0%. 3. The opening ratio of the opening cloth is 20-4.
The cutting tool according to claim 2, wherein the cutting tool is 0%. 4. An inorganic fiber cloth, an alumina fiber cloth, an alumina-silica fiber cloth, a silica fiber cloth,
The cutting tool according to any one of claims 1 to 3, wherein the cutting tool is any one of a silicon carbide fiber cloth, a carbon fiber cloth, and a glass fiber cloth. 5. The ceramic fiber cloth according to claim 1, wherein the cloth is plain weave, twill weave, or triaxial weave.
A cutting tool according to any one of claims 1 to 4. 6. The cutting tool according to claim 1, wherein the resin binder is a thermosetting resin such as an epoxy resin or a phenol resin. 7. The abrasive grains are diamond, silicon carbide,
The cutting tool according to any one of claims 1 to 6, wherein the cutting tool is alumina or CBN.