Study on Radial Drilling Machine Noise

Abstract

Noise is one of the physical environmental factors affecting our health in today’s world. Noise is a physical form of pollution and is not directly harmful to the life supporting systems namely air, soil and water. Increased noise level with the technological advancement becomes a serious problem in the industries and it has become a crucial occupational hazard to its workers. Therefore it is necessary to study the noise generated by the machines at the work place. The present work includes the study on a radial drilling machine noise. First the sound power of the machine is calculated by using an imaginary rectangular parallelepiped surface surrounded the source of noise. Equivalent continuous sound level (LAeq) is calculated at the different reference points of the parallelepiped. Sound power is calculated at two different feeds by varying five spindle speeds. It is found that sound power increases with increase in spindle speed. Sound pressure level measurement of a drilling operation at 1-1 octave band is carried out at different machining conditions to find out the parameters for optimum working conditions. Different parameters considered for the drilling operation are feed rate, spindle speed, diameter of drill bit and different workpiece materials. Sound level is recorded at each combination of the design parameters obtained by full factorial design. Frequency spectrum analysis has also been carried out to obtain the frequency range produces more sound level. It is found that the optimum parameters for less sound level are same for most of the cases and mid frequency sound waves are dominant for noise pollution at the work place. Environmental conditions and location of the machine also affects the sound pressure level generated by the machine.