Automation of Pneumatic Throttle Check Valves by Using Novel Multi-Stable Solenoids

Abstract

Multi-stable solenoids are novel energy-efficient actuator structures, which can hold any armature position powerless. Power is only required to change the armature position. They combine the continuous adjustability of proportional solenoids with the energy efficiency of polarised magnetic circuits. Thus, they are well suited for automating pneumatic throttle check valves, in order to set the throttle cross section and thus the cylinder piston velocity to a specific value and hold it for a certain time. This is useful in industry 4.0 context to produce on demand with various required piston velocities or for gradual compensation for increasing frictional forces during cylinder lifetime. The focus of this paper is the application of novel multi-stable solenoids for replacing the todays widely used manual adjustment of throttle check valves. Therefore, two different throttle valves are designed: a spool valve and a poppet valve. They are based on the transfer characteristic of a conventional throttle check valve. The flow behaviour of both valves is investigated to show the principal transfer behaviour and disturbances. The valves are equipped with a multi-stable solenoid for demonstrating the adjustability of the throttle's volume flow rate and on that basis the adjustability of the piston velocity in a pneumatic cylinder drive.