CZ307395B6 - A grinding disc - Google Patents

Abstract

The invention relates to a grinding disc provided, on its periphery, with a 3 to 20 mm thick layer of an abrasive bonded with a binder, wherein the abrasive layer (2) is based on AlOand/or SiC and the binder is selected from the group of ceramic, glass-ceramic and synthetic resin.

Description

Technical field

BACKGROUND OF THE INVENTION The present invention relates to the construction of a grinding wheel provided with a thin layer of binder bonded abrasive, which serves to grind and precisely finish the surface while being able to be refurbished after use of the thin abrasive layer.

BACKGROUND OF THE INVENTION

At present, thin-film wheels with abrasive grains of cubic boron nitride (CBN) and polycrystalline diamond (D) bonded primarily with resin binder are used. The thin layer is used in this case because of the high cost of the abrasive material. These tools wear relatively slowly, but despite the thin layer of abrasive - 3 to 12 mm, they have a high price in tens of thousands of CZK. After the grain has been worn, the tools are dressed with diamond or a dressing block made of abrasive. Metal disks, primarily made of aluminum alloys, are used as carriers. On these discs, the abrasive binder is applied to the space provided. Another solution is a metal binder that has a long service life and a long grinding time of the same properties. This binder can only be used for high-hard abrasive materials such as CBN and D. This process can be repeated until the bearing capacity of the thin layer of abrasive and metal binder is exhausted.

The second group of grinding tools consists of monolithic tools. These consist of abrasive grain and binder. The abrasive grain used in these cases is an inexpensive version of the grain, namely corundum and silicon carbide. Due to the lower hardness of the grain, it is worn out and therefore these tools are sharpened by so-called dressing. The disturbed grains and the surface layer are removed with the diamond grain of the dressing tool. In this way the tool can be dressed and used to the desired cutting speed and diameter.

In recent years, a group of new abrasive materials has been created using a new technology based on Al ₂ O ₃ - artificial corundum, also called microcrystalline corundum. These grains are constantly developing, compared to conventional artificial corundum and have a 20 times longer life and on the market there are grains for high stock removal and other modifications.

All these abrasive grains are used for monolithic tools simply because their price is at least 10 to 20 times lower than the price of CBN and D grains. and providing the desired cutting speed that varies with diameter, and it is necessary to use machines with a continuous change in tool speed.

The disadvantage is that the cost of the CBN or D abrasive thin-layer tool is high and that the tool cannot be used for smaller production runs or for single-piece production. It depends on classic monolithic instruments. After wear of the thin layer, the tool disc is unusable and is discharged into the metallurgical plant because its recovery for the costly layer of high-hard abrasive is inefficient.

Monolithic wheels with grain of the new production technology - microcrystalline corundum with various improved properties including special types of binder eg hollow glass-ceramic balls, do not fully utilize the whole tool volume and the user unnecessarily purchases the whole volume of abrasive material. The tool is no longer usable after the working volume has been exhausted. Also problematic is the production of a large volume tool, which is produced by pressing or casting the mixture into a mold. Inhomogeneous shaping of the shape of the tool occurs and the tool shows away from the surface

Different properties of the ground surface when using the tool. This is highly dependent on the quality of the production technology

SUMMARY OF THE INVENTION

The above drawbacks are largely overcome by a grinding wheel provided with a 3 to 20 mm thick abrasive bonded layer of the present invention on its circumference. It is based on the fact that the abrasive layer is renewable and is based on Al ₂ O ₃ and / or SiC and the binder is selected from the group of ceramic, glass-ceramic and synthetic resins.

The bonding abrasive layer is preferably attached to the periphery of the disc disk body by molding or casting.

Preferably, the abrasive layer with the binder is discontinuous for supplying liquid through the disc body through the layer to the grinding site. The peripheral surface of the disc body may have a roughened and / or smooth surface on its periphery.

The grinding wheel is in the form of a disc with a low layer of abrasive material bonded thereon. This layer can normally be dressed with a diamond dresser, and after removing the layer, the surface can be cleaned and a new layer applied, i.e. tool renovation. This will significantly reduce costs while increasing the use of abrasive material. Abrasive grains are preferably grains of higher hardness and durability bonded, for example, with ceramic, resin or glass -earm binder. The abrasive layer may have a height of 3 to 20 mm, or be interrupted by grooves to increase the effect of air or liquid flow during the grinding process. These grooves can also serve to supply fluid through the tool disc.

The tool disc can be used from conventional production of thin-film CBN or D tools. For example, it can be of aluminum alloys.

The solution is designed primarily for precision grinding and finishing of surfaces, for finishing it is possible to use a grain size lower than 0.15 mm.

This solution has these advantages. New high abrasion abrasive materials can be widely used for grinding. The tools can be used not only in piece and small-lot production, but also in large-scale production. The tool can be refurbished by cleaning the surface and applying a new layer of abrasive with binder. Abrasive usability will increase and monolithic tool waste will be reduced. The cost of a tool with a new type of abrasive is reduced.

Clarification of the drawing

The grinding wheel of the present invention will be described in more detail with reference to the accompanying drawing, in which: FIG. 1 shows an exemplary wheel in front view and FIG. 2 in a side view.

Examples of technical solutions

An exemplary thin film-type grinding wheel with the possibility of restoration comprises a metal disc 1 with the chuck opening 3 to clamp the flange and the layer 2 abrasives A1 ₂ O ₃ with a binder deposited on the circumference of the disc first

An exemplary solution can be accomplished by pressing and curing a mixture of abrasive grains of microcrystalline corundum and white corundum with a ceramic binder, a glass ceramic binder or a binder synthetic resin with a layer height of 12 mm.

-2GB 307395 B6

In other cases, similar grains including silicon carbide grains, new types of SiC-based abrasive grains can be used. The size of the disc is not limited, it is based on the type of grinding machine used.

The bonding abrasive layer is attached to the periphery of the disc disk body by molding or casting.

The binder layer with the binder is discontinuous for supplying liquid through the disc body through the layer to the grinding site. The peripheral surface of the disc body 1 has a roughened and / or smooth surface on its periphery.

Industrial applicability

Thin-layer refinable grinding wheel can be used in all types of production from piece to mass. It will enable to introduce cheaper new types of abrasive grains for wider use. The grinding wheel can be used both for precision grinding and for finishing surfaces while achieving high quality parameters. To some extent, a cheaper and more economical alternative to the CBN and D grain grinding wheels will be produced.

Claims (5)

PATENT CLAIMS A grinding wheel provided with a 3 to 20 mm thick abrasive bonded layer on its circumference, characterized in that the abrasive layer (2) is renewable and is based on Al ₂ O ₃ and / or SiC, wherein the binder is selected from Ceramic, glass-ceramic and synthetic resins. Grinding wheel according to claim 1, characterized in that the abrasive layer (2) with a binder is attached to the periphery of the disk body (1) by pressing in the mold. Grinding wheel according to claim 1, characterized in that the abrasive layer (2) with a binder is attached to the periphery of the disk body (1) by casting into the mold. Grinding wheel according to any one of the preceding claims, characterized in that the abrasive layer (2) with the binder is discontinuous for supplying liquid through the disc body (1) through the layer (2) to the grinding point. Grinding wheel according to any one of the preceding claims, characterized in that the peripheral surface of the disc body (1) is provided on its circumference with a roughened and / or smooth surface.