Piston for controlling ignition combustion of hydrocarbon fuel in internal combustion engine by controlling generation of nuclei of fuel particles and method therefor

摘要

A piston for a reciprocating piston internal combustion engine is provided with a reaction chamber (44, 144) communicating with a recessed area (42, 142) of the piston through a restricted continuous slot orifice (46, 146) that is configured to create a choked fluid flow condition between the combustion chamber (30, 130) and the reaction chamber at all engine operating speeds. Fuel is supplied to the reaction chamber and undergoes a controlled, cold frame reaction process while in intimate contact with the crown portion (54) of the piston (14). The reaction produces fuel radicals in sufficient quantity to seed subsequent fuel charges to properly condition the charge for predetermined desired ignition and combustion characteristics. The choking orifice (46, 146) ensures that outward flow of radicals from the reaction chamber is controlled to the extent that they will be maintained in the combustion chamber following an exhaust event of the combustion cycle so they will be available during a subsequent compression stroke of the piston for seeding the subsequent charge. The radical population in the subsequent charge conditions the charge to obtain dependable and predictable ignition in a compression ignition engine as well as knock free combustion at relatively lean air to fuel ratios in a spark ignited engine.