Caterpillar Inc.
Engine and gas exchange valve with under-head fillet contoured for chordal stress mitigation

Abstract:

A gas exchange valve in an internal combustion engine includes a valve head having a sealing face structured to contact a valve seat and defining a face angle. The valve head further includes an under-head fillet transitioning from the inner sealing face to a valve stem, and defining a chordal stress zone within the under-head fillet. The under-head fillet is formed by a material distributed according to a stress-diffusing contour within the chordal stress zone, and is blended with the inner sealing face at a blend angle that is less than the face angle and is in a range of about 18.degree. to about 35.degree.. The valve head contour is associated with resistance to chordal stress-induced fatigue failure.