Electro-Pneumatic Control Valve for EGR/ATC Actuation

The dual solenoid control valve was Initially designed as a low cost interface element between digital electronics and an automotive vacuum-spring motor such as the one found on Exhaust Gas Recirculation (EGR) valves. By using two coaxially located normally closed solenoids continuous air bleed is not required from the vacuum source. The direct acting solenoids have a large 0.5 SCFM flow capacity and a quick six millisecond opening and two millisecond closing time. The unit is well suited for pulse width modulation control. Ambient tests were conducted from -40°F to +250°F without any significant change in the performance characteristics of the unit. Possible applications for this electro-vacuum interface are in EGR valve control, Automatic Temperature Control (ATC), and as a remote throttle actuator on diesel engines.