Patent ID: 7753037

Claim:
A homogeneous charge compression ignition engine comprising: a first cylinder and a second cylinder having mutually different ignition timings and in which an EGR gas is introduced into said second cylinder at least in an early stage of a compression stroke of said second cylinder, using a pressure in a combustion chamber at a part of a power stroke of said first cylinder, thereby making the pressure in the combustion chamber in the early stage of the compression stroke of said second cylinder higher than a pressure of an intake port, wherein an exhaust valve of said first cylinder is opened in a latter half of the power stroke to generate a pressure wave by a blowdown gas of said first cylinder, wherein an exhaust valve of said second cylinder starts to open before a bottom dead center of an intake stroke and is closed after an intake valve of said second cylinder is closed in the early stage of the compression stroke, and wherein an exhaust pipe length from said first cylinder to said second cylinder is set so as to cause the pressure wave by the blowdown gas of said first cylinder to reach an exhaust port of said second cylinder after the intake valve of said second cylinder is closed in the early stage of the compression stroke of said second cylinder.