Abstract
Power tools play a large role in the construction industry. From power nailers to circular saws, these tools provide an enormous and relatively untapped opportunity in the field of dynamic analysis. The intent of this paper is to analyze a unique power construction tool and then develop a computer model to simulate its dynamics. The study model used in this investigation is a nailer which utilizes a linear internal combustion engine to drive nails into wood and is completely cordless and portable. Analytical expressions for the forces acting on the system are developed and the obtained analytical results are verified experimentally. The computer model is then used to parametrically study the performance of this nailer under varying conditions. The parameters varied are the piston mass, by choosing materials with different densities, and the bumper material on which the piston impacts, to vary the coefficient of restitution between the bumper and piston. The jump discontinuity in the system velocities is predicted using a momentum balance and the restitution conditions. The coefficient of restitutions used in this study are determined experimentally using a simple impact test. It is found that there is an ideal piston mass that will provide the highest kinetic energy at the end of the stroke. It is also shown that the lower the coefficient of restitution between the piston and bumper, the lower the piston rebound height and velocity. The material chosen as having the lowest coefficient of restitution was not acceptable as an alternative material due to its low durometer, or hardness. In addition, the high elastic-energy-absorption capacity of this material may also result in increased heating of the bumper resulting in premature failure.
