Profiled cover plate for a piston

An internal combustion engine piston, comprising:

• a crown having a piston axis and defining an annular cavity between an inner wall, an outer wall, and a top wall that extends between the inner and outer walls, the annular cavity including an opening opposite the top wall arranged such that the opening extends between a first end of the outer wall and a second end of the inner wall, wherein the inner wall, the outer wall, the top wall, and the annular cavity at least partially define a cooling gallery, wherein the inner wall, the outer wall, and the top wall form an upper boundary of the cooling gallery, the upper boundary has a convex shape relative to the piston axis that extends between the first end of the outer wall and the second end of the inner wall;
• and
• a cover plate is assembled with the first end of the outer wall and the second end of the inner wall in the opening to form a lower boundary of the cooling gallery thereby enclosing the cooling gallery within the piston crown, wherein the cover plate includes a plurality of crests separated by a plurality of troughs wherein the crests and troughs are arranged in a sinusoidal wave profile perpendicular to the piston axis to form a variable volume profile of the cooling gallery, wherein the plurality of troughs extend to the first and second ends of the outer and inner walls to increase the volume profile of the cooling gallery, wherein the plurality of troughs extend below the first and second ends of the outer and inner walls, wherein each of the plurality of crests has a convex shape and each of the plurality of troughs has a concave shape.