Method and apparatus for making a two piece unitary piston

摘要

Past pistons have been susceptible to reduced longevity due to increased forces of combustion thereon during operating cycles of an engine. The present two piece unitary piston increases the longevity of pistons used with increased forces of combustion. For example, a head member has a crown portion defining a ring band portion having a bottom surface and a support portion. And, a skirt member defines a ring band support surface and a mating portion. The head member and the skirt member have a preestablished material strength being generally the same. The head member and the skirt member are joined at an interface of the support portion and the mating portion by an interference fit and are joined at the interface of the bottom surface and the ring band support surface by a weld. The force of combustion acting on the crown portion is resisted by the ring band support surface being in contacting relationship with the bottom surface. Thus, the skirt member structure supports and resists the bending moment of the combustion forces on the head member.