Methodical instructions for independent work "Calculations of dangerous zones, protective fences and safety devices"

Abstract

Each dangerous production factor has two main characteristics - the zone of action, which is called dangerous, and the time of action. A dangerous zone is a space in which a dangerous and (or) harmful production factor is likely to affect an employee. During work at height, the area located below the work platform is considered a dangerous zone; during the operation of lifting machines (electric hoist, crane beam), the dangerous zone is determined by the distance of the possible departure of the load in the event of a break in one of the slings. Permanent danger zones exist or arise in chain, belt or gear transmissions, when processing parts on lathes, circular saws and sharpening machines, near cutting tools, working bodies of many machines, near presses, pneumatic and hydraulic hammers, stamping machines, under machines and platforms , lifted using a hydraulic or other lifting system. The dimensions of the dangerous zone in space can be constant (the zone between the rollers, the belt and the pulley) and variable (the cutting zone when changing the mode and nature of processing, changing the cutting tool, etc.). The presence of a dangerous zone can be caused by the danger of electric shock, as well as the impact of thermal, electromagnetic and ionizing radiation, noise, vibration, ultrasound, harmful vapors and gases, dust, the possibility of injury by flying particles of the material, tool, the flight of the processed part, etc. 5 When designing and operating technological equipment, it is necessary to provide for the use of devices that either exclude the possibility of human contact with the dangerous zone, or reduce this danger.