Modeling of the reciprocating, pneumatic impact hammer

The motion of the reciprocating, pneumatic impact tool, the air-driven piston inside the tool, the chisel mounted into the tool, and the specifically designed single degree-of-freedom spring-damper-mass test fixture were modeled with a MATLAB computer code. The three tools modeled and evaluated experimentally were the Ingersoll-Rand IR-121 impact tool, the Sears Craftsman Medium Duty impact tool, and the ATSCO No.2 impact tool; The computer model of the accelerations of the tool and the test fixture mass were compared to the experimental data obtained on the actual test fixture by the three tools modeled. The correlation between the experimental data and the modeled data is high in both the time domain and the frequency domain; The computer model is modified to include an air spring vibration attenuation mechanism. The model is used to tune the attenuation device as well as predict the force produced by the chisel into the work piece and the vibration through the tool into the hand-arm of the operator. The computer program allows other attenuation methods to be modeled and evaluated prior to actual construction