| 主权项 |
1. A piston for an internal combustion engine, the piston comprising:
a piston body including
an outer cylindrical surface defining a longitudinal piston axis;a combustion face defining a compound combustion bowl; anda compound rim extending radially outward from the compound combustion bowl to the outer cylindrical surface, the compound combustion bowl including a convex inner bowl surface defining a conical projection and a concave outer bowl surface, the compound rim including a flat outer rim surface adjoining the outer cylindrical surface, and a convex inner rim surface adjoining the compound combustion bowl, a cone angle of the conical projection is less than or equal to about 135 degrees, the concave outer bowl surface has a first radius of curvature ranging from 7 mm to 20 mm, and the convex inner bowl surface transitions smoothly to the concave outer bowl surface, and the convex inner rim surface transitions abruptly to the concave outer bowl surface at an edge of the compound combustion bowl, and the convex inner rim surface has a second radius of curvature ranging from 40 mm to 70 mm, such that the edge of the compound combustion bowl is recessed from a plane defined by the flat outer rim surface along the longitudinal piston axis. |
