Mathematical modeling of drives with tandem pneumatic cylinders
The article considers the issue of mathematical modeling of tandem pneumatic cylinders. Despite the fact that the mathematical description of the operation of drives with single-piston cylinders is considered in sufficient detail in the literature, the peculiarity of drives with tandem cylinders, namely the commutation of their working cavities with pneumatic discharge and exhaust lines through one pneumatic distributor, requires the formation of a certain approach to their mathematical description. The paper shows two developed versions of mathematical models that describe their work. The first option involves taking into account some conventional intermediate chambers behind the pneumatic distributor, where the division and combination of compressed air flows between the pneumatic distributor and the working cavities of the tandem pneumatic cylinder takes place. The second one (the simplified) considers the working cavities of the cylinder independently. Comparison of the results of mathematical modeling for two options showed a fairly significant difference in the time of movement of the piston of the cylinder. Moreover, it can be seen from the results that this difference is primarily associated with the distribution of air pressure between the intermediate chambers and the working cavities of the cylinder. According to the obtained results, it follows that when developing pneumatic drives and pneumatic actuators with tandem pneumatic cylinders, despite the complexity of the calculation, it is preferable to take into account in the mathematical model the intermediate chambers, where the division and combination of compressed air flows takes place. The developed model can be used in the design of pneumatic drives of various machines and mechanisms that use tandem pneumatic cylinders. This modeling approach can be used in the study of other multi-piston pneumatic engines or drives with several engines controlled by a single pneumatic switchgear.