Modelling, Simulation and Validation of the Pneumatic End-Position Cylinder Cushioning
Keywords:pneumatic cylinder, end cushioning, thermocouple, friction, pneumatics, Stribeck curve, throttle
In this paper a model of the pneumatic cylinder with an integrated pneumatic end cushioning is presented. This model is needed to simulate and analyze the thermodynamical possesses in the pneumatic end cushioning and to elaborate a novel design strategy for damping systems with a higher capability on kinetic energy absorption and robust performance even with fluctuating operational conditions, such as supply pressure, inertial load or travel speed. To validate this model, the results of the experimentally based parametrization of the friction force in the cylinder sealings are compared for a Stribeck friction model and its modifications. A new approach suitable for an accurate approximation of the measured friction data within a wide range of pressure (2…8 barrel) and piston speed (0…0.8 m/s) is proposed. In the next step a flow rate characteristic of the integrated end cushioning throttle is experimentally obtained and analyzed. These data are used to parametrize the lumped parameters model of the cylinder with an end cushioning. Pressure and temperature in the cushioning volume and piston displacement are measured for different openings of the cushioning throttle to prove the validity of the model. The model will be used further for sensitivity analysis and robust optimization of the cushioning system design.