Mathematical Modeling of the Process of the Interaction of the Cutting Diamond Disk with the Environment

Abstract

Cutting of solid construction materials during repair and restoration work is car-ried out with diamond discs and CBN discs on a metal bond with speeds up to 80 m / s. The cutting process is accompanied by significant heat generation, as a re-sult of which the cutting disc heats up intensively. When heated to a temperature of 500–600 ºС, the strength characteristics of the disk are halved, which can lead to rupture and seizure of the disk and loss of the diamond layer. Disk heating temperature should not exceed 600 ºС. The operating time of the diamond cutting disc is the time during which it is heated during continuous operation to a temper-ature of 600 ºС. The cooling media used in cutting are intensively discarded by the air flows of the boundary layer of air that circulate near the rotating circle. Knowing the speed and dimensional characteristics of these flows, we can devel-op a rational cooling system. The purpose of the study is to determine the condi-tions of transportation of cooling media, ensuring their guaranteed entry into the cutting zone to create the maximum cooling effect. In work with the help of math-ematical modeling defined the speeds of flowing air in the near-wall area and in the area tangential to the disk. The thickness of the air layer, which rotates at a speed of up to 0.5 circle speed was determined, taking this value as the “bounda-ry layer thickness”. The change in air pressure in the cutting zone between the cutting grains was determined too. It is established that air pressure can vary from 0.5 - 1.7 MPa. In this regard, the cooling medium supplied under the circle, inevi-tably displaced from the cutting zone. In order for the cooling medium to pene-trate into the cutting zone, it must be fed under a pressure that exceeds the air pressure in the cutting zone.