| 主权项 |
1. A combustion chamber structure for an internal combustion engine including at least one cylinder with longitudinally-separated exhaust and intake ports and a pair of pistons disposed in opposition to one another in a bore of the cylinder, the combustion chamber structure including a squish zone defined between complementary squish surfaces on opposing end surfaces of the pistons, an elongated cavity defined between the opposing end surfaces, and a pair of diametrically opposed injection ports that extend through peripheral areas of the end surfaces into the cavity, in which:
the end surface of each piston defines the combustion chamber with the end surface of the opposing piston, and the end surface has a circumferential area centered on a longitudinal axis of the piston to define a periphery of the end surface, and a bowl within the periphery, the bowl defining a concave surface with a first portion curving inwardly from a plane containing the circumferential area toward the interior of the piston and a second portion curving outwardly from the interior of the piston through the plane; further in which, as the pair of pistons approach top dead center in the cylinder, compressed air flows from the periphery of the end surface of each piston, through two or more squish channels defined by the squish surfaces, the squish channels skewed in different directions with respect to a diametrical direction of the cylinder, into the combustion chamber; the concave surface of each end surface deflects the compressed air into a tumble motion; and the compressed air swirls about a major axis of the combustion chamber, in which the pair of injection ports are positioned on the major axis of the combustion chamber. |
