Candidate: Mauro Damián Hené
Program: UFSC / POSMEC
Date: December, 2010
Advisor: Victor Juliano De Negri
Abstract: In the last years, many studies have been published in order to improve the performance of the pneumatic positioning systems, mainly about new techniques of control, friction behavior in actuators and the influence of the directional proportional valve in the system performance. The valves and the cylinders have intrinsic behavior limitations due to air compressibility, non-linearities associated with the air flow in the valve and mechanical friction on the cylinder. These factors make systems difficult to control pneumatic. However, it seems to be possible to improve the pneumatic positioning systems when it is reached a correct sizing of the valve and the cylinder and when the operational condition of the system is totally understood. In positioning systems, the operational condition that determines the minimum size required for the valve is established in the middle point of the stroke between the two positions in steady state where the high speed occurs. In on-off pneumatic systems, the steady state condition with constant speed is the operating system requirement. In this scenario, this dissertation studies the influence of values obtained from manufacturer catalogs valves compared to values obtained by experimental tests according to ISO 6358 in the determination of the operating point of pneumatic systems. The study also involves the analysis of temperature changes in the different work ports of the pneumatic circuit during the actuator displacement. With the reached results, valid for both on-off systems and positioning systems, it is proposed a calculation method that helps the design engineer in the choice of pneumatic components, presenting an alternative concept against the traditional methods of sizing.
HENÉ, M. D.. Estudo Teórico-Experimental do Ponto de Operação e Proposição de Método de Dimensionamento para Sistemas Pneumáticos. 2010. Dissertação (Programa de Pós Graduação em Engenharia Mecânica), 129 p. Universidade Federal de Santa Catarina.