Abstract: A Roots blower driven by a direct-current motor provided to a recirculation duct for connecting an exhaust duct and an intake duct to extract a part of exhaust gas of a diesel engine to recirculate to an intake side. Accordingly, even when a differential pressure between an exhaust side and the intake side, or even when a pressure on the intake side is higher than the exhaust side fluctuates, the exhaust gas flowing to the recirculation duct can be forcibly pumped by the Roots blower while appropriately controlling flow rate thereof, so that an optimum recirculation amount of exhaust gas in accordance with operation condition of the diesel engine can be recirculated to the intake side.

Abstract: A fuel blended with alcohol for use in a diesel engine, which comprises a petroleum fuel, methanol, and a higher alcohol having 10 to 16 carbon atoms as a mutual solvent for said petroleum fuel and methanol.

Abstract: A fuel blended with alcohol for use in a diesel engine, which comprises a petroleum fuel, ethanol, and gasoline as a mutual solvent for said petroleum fuel and ethanol.

Abstract: A fuel injection control system for an internal combustion engine, comprising an injection pump connected to the engine and driven thereby, a fuel injection valve connected to the injection pump, the fuel injection valve having a piston chamber and a plunger chamber defined therein, a solenoid-operated spool valve connected to the injection pump on its input side and the piston chamber of the fuel injection valve on its output side, a solenoid-operated metering valve connected to the injection pump on its input side and the plunger chamber of the fuel injection valve on its output side, and a controller connected to the spool valve and the metering valve for controlling the same.

Abstract: A combustion chamber for an internal combustion engine of the direct injection type defined by a cylinder head, a cylinder liner and a piston head, the piston head having formed therein a cavity in which air swirl can be produced by a known means.A fuel injection valve having a plurality of fuel injection nozzles is disposed above the cavity for injecting jets of fuel radially against the cavity wall.The cavity comprises an equilateral polygonal cavity formed in the upper part of the piston head and a toroidal cavity formed continuously to the polygonal cavity in the lower part of the piston head. The equilateral polygonal cavity has rounded corners formed therein, the ratio of the radius of the rounded corners to that of a inscribed circle of the equilateral polygonal cavity being from about 0.05 to about 0.8.

Abstract: A combustion chamber for an internal combustion engine of the direct injection type formed by a cylinder head, a cylinder liner and a piston head, the piston head having formed therein a cavity in which air swirl can be produced by a known device. Fuel injection nozzles are disposed substantially in the central part of said cavity for injecting jets of fuel radially against the cavity wall. Said cavity comprises a generally toroidal cavity formed in said piston head and a plurality of corner cavities formed continuously to said toroidal cavity, each of said corner cavities being defined by a generally linear wall tangent to the inner peripheral wall of said toroidal cavity and a generally semi-circular wall interconnecting said linear wall and the inner peripheral wall of said toroidal cavity, said linear wall being formed upstream side of said air swirl.

Abstract: A combustion chamber for an internal combustion engine of the direct injection type formed by a cylinder head, a cylinder liner and a piston head, the piston head having formed therein a cavity in which the air swirl can be produced by known means.A fuel injection nozzle is disposed substantially in the central part of said cavity for injecting jets of fuel radially against the cavity wall.Said cavity comprises an equilateral polygonal cavity formed in the upper part of said piston head and a toroidal cavity formed continuously to said polygonal cavity in the lower part of said piston head.