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 carried 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 result of which the cutting disc heats up intensively. When heated to a temperature of 500–600 °C, 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 °C. The operating time of the diamond cutting disc is the time during which it is heated during continuous operation to a temperature of 600 °C. 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 develop a rational cooling system. The purpose of the study is to determine the conditions of transportation of cooling media, ensuring their guaranteed entry into the cutting zone to create the maximum cooling effect. This work defines the speeds of flowing air in the near-wall area and in the area tangential to the disk with the help of mathematical modeling. 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 “boundary 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, inevitably displaced from the cutting zone. In order for the cooling medium to penetrate into the cutting zone, it must be fed under a pressure that exceeds the air pressure in the cutting zone.