JPS6144576A - Grinding wheel - Google Patents

Abstract

PURPOSE:To excellently and uniformly perform grinding finish on an object of grinding and reduce frequency of repairs such as reforming of the master body surface, dressing and the like for a wheel by forming ceramic material like alumina into spherical grains and distributing them homogeneously. CONSTITUTION:Ceramic material like alumina is formed into spherical grains, which are subsequently made into grinding grains through sintering. Through mixedly kneading these grinding grains, binding agent and additive agent, the surface of each grinding grain is covered by the binding agent and the additive agent. The grinding grains, covered as abovementioned, are filled in a metal mould and pressurized to be formed into an optional shape. A desired grinding wheel is obtained by binding this formed stuff through heating it at the sintering temperature for the binding agent.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a grindstone used for grinding metal materials, organic materials, inorganic materials, and the like.

[Prior art and its problems] Grinding wheels have conventionally been made of ceramic materials such as alumina,
It is manufactured by sintering abrasive grains made from crushed and classified natural or artificial minerals such as silicon carbide, using a binder. According to this.

Since the shape of each abrasive grain is irregularly shaped, the matrix of the grindstone is non-uniform, which causes defects such as scratches and uneven grinding to easily occur on the surface of the object to be ground. In addition, the abrasive grains contain microscopic cracks caused by the impact during mineral crushing, and these are destroyed during the grinding process of the workpiece, resulting in similar defects on the surface of the workpiece, and furthermore, the abrasiveness of the grindstone itself. It also had the disadvantage of accelerating damage.

[Object of the Invention] It is an object of the present invention to provide a grindstone that has a homogeneous internal structure that allows for a good grinding finish and that is long-lasting.

[Means for solving the problem] Abrasive grains made by granulating and sintering ceramic materials such as alumina into spherical shapes are kneaded with a binder and additives, and the surfaces of the abrasive grains are coated with the binder and additives. The molded product is filled into a mold, pressure-molded into an arbitrary shape, and the molded product is heated to the sintering temperature of the binder to bond it.

[Operation] Because the spherical abrasive grains are uniformly distributed, the object to be ground can be ground uniformly, and a good finished surface can be obtained. Furthermore, since the abrasive grains themselves are spherical granules, they do not break or fall off during grinding, thereby maintaining a good grinding finish. Moreover, the frequency of repairs such as reshaping and refinishing the surface of the base body of the whetstone can be reduced.

[Example] The abrasive grains are 1, for example, by the spraying method of molten alumina.

Alternatively, it is obtained by kneading alumina powder with a binder, extruding it under pressure, cutting it into chips, granulating it into spherical shapes with a granulator, and sintering it after granulation.
When using other hard ceramic materials as abrasive grains, they can be obtained by substantially the same method. The particle size of the abrasive grains is appropriately selected depending on the purpose, such as rough finishing or precision finishing. Next, the abrasive grains are kneaded with an appropriate amount of an inorganic or organic binder and a small amount of an inorganic or organic additive to coat the surface of each abrasive grain with the binder. Thereafter, this is filled into a predetermined mold and pressure-molded into any shape such as a disk, ring, arm, or rod (for example, the pressure density is about 2.25 g/Cm'
), and then heat the molded product to the sintering temperature of the binder (approximately 130
Heat to 0°C).

The binder is used to bond the contact points between the abrasive grains, and the additive increases the fluidity of the binder during heating so that the binder is concentrated at the contact points between the abrasive grains. Work.

The grinding wheel thus obtained is used by sharpening its surface with a diamond dresser, etc., but since the spherical abrasive grains with a substantially constant particle size are homogeneously distributed, The grain on the surface of the grinding wheel is uniform, so the surface of the object to be ground can be ground uniformly, and a good finished surface can be obtained. Since the abrasive grains themselves are atomized particles of molten alumina or agglomerated particles of alumina powder, they do not break or fall off during grinding, and maintain a good grinding finish. In addition, since appropriate ventilation gaps are formed between the abrasive grains, air and grinding oil, which are essential for grinding work, penetrate into the ventilation gaps, avoiding seizure and welding, and allowing healthy grinding work to continue. .

Next, in an experimental example, alumina grains with an average grain size of 0.25 mm were used as abrasive grains, and 15 parts of a non-staining binder and 5 parts of an organic additive were mixed with 85 parts of the abrasive grains, and the density was 2. 25g
/am3 and sintered.

As a result, the obtained grindstone had an abrasive grain volume ratio of approximately 50%, an inorganic binder volume ratio of approximately 12%, and a pore volume ratio of approximately 38%.

[Effects of the Invention] When a good polished surface is obtained, it is durable, and the frequency of repairs such as reshaping can be reduced, making it easy to handle. In addition, since the abrasive grains are spherical, there is no variation in quality, and furthermore, it can be kneaded and pressure molded during manufacturing.

It has many advantages in terms of quality, work efficiency, economy, etc., such as improved workability in firing, etc., and less wear and tear on the mold because the pressure during pressure molding is less.

Claims (1)

[Claims] Abrasive grains made by granulating and sintering a ceramic material such as alumina into a spherical shape are kneaded with a binder and additives to coat the surface of the abrasive grains with the binder and additives, and then filled into a mold. A grinding wheel, characterized in that it is formed by pressing and molding into an arbitrary shape, and heating the molded product to the sintering temperature of the binder to bond it.