公开(公告)号：US20190178203A1

公开(公告)日：2019-06-13

申请号：US15838648

申请日：2017-12-12

Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC

Inventor： Ramachandra Diwakar ,  Vicente Domenech-Llopis ,  Richard C Peterson ,  Alberto Lorenzo Vassallo

IPC: F02F3/02 ,  F02B23/06

Abstract: A piston for a diesel engine includes a piston body having a skirt and crown. The piston body has portions defining an outer combustion bowl and an inner combustion bowl within the piston body through the crown. The outer combustion bowl has a curved annular side wall extending from the crown surface and an annular flat shelf extending from the curved annular side wall. The new stepped bowl design integrates a bottom profile with smoothly varying curvature and a sharp step at the top. The annular flat shelf is recessed a distance in the range of 2.5-4.5 millimeters from a line coplanar with the crown surface. The piston body defines an outer convex curved surface connecting the curved annular side wall to the crown surface. The outer convex curved surface has a radius of curvature in the range of 0.25-0.75 millimeter.

公开(公告)号：US20210087997A1

公开(公告)日：2021-03-25

申请号：US16580800

申请日：2019-09-24

Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC

Inventor： Vicent Domenech-Llopis ,  Ramachandra Diwakar

IPC: F02F3/26 ,  F02B23/06 ,  F02F3/28

Abstract: A piston for an internal combustion engine includes a piston wall defining an outer perimeter of the piston, and a piston face located at an end of the piston wall. The piston face includes a radially-extending outer face, and a combustion bowl formed therein and recessed from the outer face. The combustion bowl includes an upper bowl including a flat upper bowl radial surface recessed from the outer face a distance in the range from 3.5 to 4.5 millimeters, and a lower bowl including a lower bowl surface recessed to a maximum bowl depth from the flat upper bowl axial surface in the range from 10.4 to 13.4 millimeters. The piston face is axisymmetric about a piston central axis.