Patent Number: 6,167,859

Title: Fiber reinforced ceramic matrix composite internal combustion engine intake/exhaust valves

Abstract: A fracture-resistant, thermally stable intake or exhaust valve for an internal combustion (IC) engine. The valve has a stem portion and a head portion, both of which are formed of fiber reinforced ceramic matrix composite (FRCMC) material. This FRCMC material generally includes a polymer-derived ceramic resin in its ceramic state, fibers, and filler materials. Employing FRCMC material to form the valve is advantageous as FRCMC material is highly temperature resistant and temperature stable, thereby allowing for increased engine operating temperatures. FRCMC material is also ductile, thus making the valve fracture resistant. The FRCMC material is also flaw-insensitive in that any flaw within the structure of the valve will not result in cracking and failure. In addition, FRCMC valves are considerably lighter than the existing metal valves. This provides an opportunity to reduce the weight of the overall valve train, thereby increasing engine performance. The addition of certain filler materials allows the FRCMC material to be tailored to exhibit a desired degree of harness and/or a desired coefficient of friction. Increasing the hardness of the head of the valve allows it to better withstand the violent environment of the engine cylinder, and lowering the coefficient of friction facilitates the valve movement within the engine.

Inventors: Strasser; Thomas Edward (Corona, CA), Atmur; Steven Donald (Riverside, CA)

Assignee: Northrop Grumman Corporation

International Classification: C04B 35/80 (20060101); F01L 3/02 (20060101); F01L 003/02 ()

Expiration Date: 01/02/2018