DYNAMIC CORRECTION OF EXCITATION IN HAND-HELD ELECTRO-PNEUMATIC PERCUSSION MACHINES

Vibration levels experienced by operators of hand-held percussion machines are high, causing injuries when operated for the durations common in industry, which is why the design of low-vibration percussion machines is a significant problem. One of the main sources of hazardous vibration of electro-pneumatic percussion machines is an impulsive pressure force developed within an air cushion and applied directly to the machine casing. This paper shows that an additional flexible element added to the exciting piston of the electro-pneumatic hammer improves excitation performance, leading to an extension of acceleration time and a reduction in the intensity of impulses of pneumatic impacts thereby relieving load on the operator. The concept proposed is substantiated by wide simulation of the machine dynamics.