CS248372B1 - Grinding wheel - Google Patents

Abstract

A significant reduction in the formation of cutting fluid aerosol during grinding is achieved by surface-treating the non-functional parts of the wheel and covering or filling the pores with a material with a surface roughness at least one class lower than the roughness of the functional part of the wheel. The filling material can be, for example, a plastic substance or varnish, preferably with an admixture of sulfur, or a metal with a lower melting point.

Description

The present invention relates to grinding wheels used in grinding in the presence of cutting fluids, oils or emulsions causing aerosol formation.

The grinding wheels, made predominantly of corundum and silicon carbide, or mixtures thereof, have a relatively high surface roughness and porosity, depending on the abrasive used.

During grinding, in the presence of cutting fluids, oil or emulsion, a large amount of aerosol of the cutting fluid used is generated by the rotation of the wheel and the pores present in the wheel. The conditions for aerosol formation are more favorable, the greater the porosity and peripheral speed of the disc.

Aerosol significantly worsens not only the working environment for the grinding machine operator, but often the whole workshop. For this reason it is necessary to mount the disc covers, eventually, the covers of the whole grinder and efficient exhaustion.

This way of protecting workers from negative aerosol exposure is often costly and often imperfect. In some cases, the machine cover or disc cover cannot be installed for business reasons. The suction device is noisy and leads to heat loss.

It is known to treat the disks by hydrophilization, thereby increasing the wettability and water absorption of the disks. This treatment permits the penetration of the alkali silicate solution into the entire mass of the disc, but the surface roughness of the functional and non-functional surfaces does not change, so that the possibility of aerosol formation is not positively influenced. The hydrophilization of the wheels is only performed when grinding water-based liquids.

The abovementioned deficiencies are substantially eliminated by the grinding wheel according to the invention, which is based on the fact that the non-functional parts of the wheel are covered by a filler material with a surface roughness of at least a class less than the roughness of the functional part of the wheel. For example, the filler may be a plastics material or lacquer, preferably with an admixture of sulfur, or a metal with a lower melting point.

An advantage of the measures according to the invention is, in particular, the protection of the worker from the negative action of aerosol, qualitatively at a higher level. The surface-treated grinding wheel produces considerably less aerosol than the surface-treated wheel, i.e., prevents a negative effect.

Due to the treatment of the non-functional parts of the side of the grinding wheel, by removing the pores which act as a fan when the wheel is rotating, a substantially smaller amount of aerosol is generated.

Using a suitable wheel guard and side grinding wheel, the BUA 16A round grinder reduced the amount of oil aerosol produced to 6.6% compared to the original condition, untreated (100%).

The treatment of the non-functional part of the wheel, i.e. by circumferential grinding of the sides of the grinding wheel and the removal of the pores, can be accomplished in various ways, eg varnish, plastic, metal with lower melting point.

Example 1

The grinding wheel A99 3K 8V adjusted so that a broken part of the disc is filled with a filler based on epoxy resins and has a roughness R _a »1.6 mm, while the untreated discs functional part has a roughness R _g · 12.5 mm.

Example 2

Corundum wheel A96 25L 9V, 0 250/76 x 20. The wheel is used for round grinding by circumference. The pores on both sides of the disc (0 250) were filled with a phenol-formaldehyde resin, preferably containing sulfur, by means of a spatula, and sprayed with nitroemail after the material had hardened.

C 2002. The roughness of the disc flanks smaller R _and S of 3.6 mm was achieved.

Example 3

Silicon carbide wheel C49 25L 9V, 0 250/76 x 20, designed for round grinding. A plastic foil (novodur) was steamed on both sides of the disk. In this way, the pores have been covered in which the cutting fluid can no longer penetrate.

The use of surface-treated grinding wheels is possible for all wheels, but is particularly suitable for grinding wheels with high porosity, higher peripheral speeds and when using cutting oils in emulsion.

Sulfur additive is similar to conventional disk sulphurization and is intended to increase durability in the most stressed parts of the disk, i.e. the functional and non-functional edges of the disk at the edges.

Claims (4)

1. A grinding wheel used in the presence of cutting fluids, oils or emulsions, characterized by the fact that its non-functional parts are covered by a filler to a surface roughness R _{g of} at least 1 class less than that of the functional part of the wheel. Grinding wheel according to Claim 1, characterized in that the filler is a plastic material, preferably containing sulfur. Grinding wheel according to claim 1 or 2, characterized in that the filler is a lacquer, preferably containing sulfur. 4. The grinding wheel of claim 1 wherein the filler is a metal with a melting point of less than 350 [deg.] C.