Design Process for Resin Transfer Molded, Fiber Reinforced Poppet Valves for Internal Combustion Engines

Abstract

A project has been undertaken to design, build and test internal combustion engine poppet valves made from resin transfer molded (RTM) Fiber Reinforced Composites (FRCs). For poppet-valve engines, the valve train mass and stiffness is of particular importance because valve train natural frequency and the onset of valve float and bounce typically limit the engine operating speed. This in turn limits engine power and performance. FRC poppet valves offer the potential for substantial mass reduction as well as increased component stiffness. This enables reduced power consumption by the valve train, and increased overall engine efficiency. Resin transfer molding was chosen because of potential for high-volume production and near-net shape products. Valve design details include; identification of valve operating requirements, fiber orientations, material selection, and evaluation of potential solutions using computerized structural analysis. Mold design includes; mold configuration requirements, fiber placement strategies evaluated, intermediate validation testing done and initial prototype configuration. Results include the final valve design for an exhaust valve, fiber and matrix material selection, fiber placement strategy, and mold configuration. Plans for additional validation testing are presented.

Inorganic Polymer Matrix Composite Strength Related to Interface Condition

“…These polymers have been tailored for resin transfer molding (RTM) and resin infusion molding. Fiber reinforced polyimide engine intake valves have been under investigation for a number of years, and successful prototypes have been produced using RTM [1,2,3]. While the potential exists to survive the temperatures of the intake valve using these high temperature polymers, the roughly 800 °C requirement for an exhaust valve is clearly out of reach for these polyimides.…”