Connecting rod for internal combustion engine

Abstract

According to the present invention a connecting rod constructed of a rigid, primary material is defined by a longitudinally extending beam having, at a first end, a piston pin bearing boss and, at a second end, a crankpin bearing boss. The longitudinally extending beam includes an opening extending from a location near the piston pin bearing boss to a location near the crankpin bearing boss to define opposing webs or legs. A secondary material having stiffness properties different from said primary material is disposed within the opening in the longitudinally extending beam. Under loads imposed on the connecting rod during the combustion event, the opposing legs exhibit a resiliency which allows inward movement, towards the beam axis thereby compressing the secondary material in the opening. The inward movement of the opposing legs, and resulting compression of the secondary material therebetween, absorbs a portion of the applied load to reduce or modify the amplitude of the force transferred to the crankpin. As the force of the combustion event diminishes through downward movement of the piston in the engine cylinder, the opposing legs move outwardly, away from the beam axis, returning to their original relationship and relieving the compressive forces imposed on the secondary material in the opening. As the webs return to the starting position, a substantial portion of the previously absorbed load, applied to the connecting rod by the combustion event, is transferred to the crankpin such that the total transmitted force is substantially the same as that of a typical connecting rod while the peak force amplitude is reduced.