FEA Based Methodology to Optimize Sealing Performance in Fuel Vapor Emission Valves

As per current global trends, low tailpipe and evaporative emissions is a major focus area in automotive development. This has led to imposition of stringent emission limits on both tailpipe and evaporative emission norms. In the field of evaporative emissions, the fuel valves must meet zero-leak of fuel to canister requirement under different operating conditions. Corresponding sealing design iterations and evaluating the performance through lab testing is time and cost consuming. Present study considers FEA based sealing analysis considering elastomeric-plastic interface using ANSYS®. The designs are evaluated by comparing surface contact of seal with valve orifice. In present study, different combinations of shape, size of plastic and elastomeric parts, material stiffness, axis position of elastomeric & plastic parts and use of supporting structure for elastomeric parts were evaluated. A methodology is provided to optimize seal design to meet zero-leak (<0.05 ccm) of fuel requirement by using right combinations of all above parameters. The results of the methodology were validated with actual prototype build and testing.