Pneumatic system

To actuate the door panels, two pneumatic cylinders are used, one on each panel. The pneumatic cylinders used are pivot-mount, double acting, with a stroke length of 12" (McMaster-Carr part number 6498K642). The cylinders are controlled using 2-position, 5-way solenoid valves producted by Amico, part number 4V210-08. The solenoid valve requires a DC 12-22V power supply, and has a working pressure of 0.15~0.8Mpa. A single pressure regulation provides a constant 22Psi (0.15Mpa) of compressed air to the pneumatic system. Since the pneumatic cylinders have a small overall dimension, they require little air flow, and the minimum pressure of the solenoid valves turned out to be too high, and resulted in unnecessarily high speeds for the door panels. To alleviate this problem four needle valves were placed between the solenoid valves and the pneumatic cylinders to regulate the air flow to and from the cylinders. The complete pneumatic circuit diagram is shown below.