Abstract: An object of the present invention is to provide a combustion chamber shape of a direct injection type diesel engine in which a black smoke generation amount can be suppressed during no-load operation while suppressing NOx and fuel consumption. The combustion chamber 5 is formed in a recessed shape in a piston top wall 3 and injecting fuel at a predetermined nozzle hole angle ? into the combustion chamber 5 from a nozzle hole 20 of a fuel injection valve having a nozzle hole center O1 substantially on a cylinder center line.

Abstract: An object of the present invention is to provide a combustion chamber shape of a direct injection type diesel engine in which a black smoke generation amount can be suppressed during no-load operation while suppressing NOx and fuel consumption. The combustion chamber 5 is formed in a recessed shape in a piston top wall 3 and injecting fuel at a predetermined nozzle hole angle ? into the combustion chamber 5 from a nozzle hole 20 of a fuel injection valve having a nozzle hole center O1 substantially on a cylinder center line.

Abstract: The present invention relates to an exhaust manifold for a supercharger-equipped internal combustion engine having multiple cylinders capable of preventing an increase in the fuel consumption and of reducing load application time. The engine satisfies at least one of the following expressions, where D is the diameter of a main tube of the exhaust manifold, d is the diameter of a branch tube, D1 is the diameter of a passage of a connection connecting the branch tube to the main tube, R is the radius in the outer peripheral side of the connection smoothly connecting the branch tube to the main tube of the exhaust manifold, and r is the radius in the inner circumference side. 1.2?(D/d)2 ?2.5, 0.8?(d/de)2?1.2, 0.7?(D/D1)2?1.4, 1.7?R/r?2.1.

Abstract: A diesel engine including a shallow-dish type combustion chamber on the top face of a piston. A fuel injection valve projects toward the combustion chamber, where a plurality of first nozzle holes are arranged in the same circumference of the fuel injection valve. A plurality of second nozzle holes having a diameter smaller than that of the first nozzle holes are provided in a circular side wall of the fuel injection valve, the circular side wall locating opposite to the tip part of the valve with respect to the first nozzle holes. The first nozzle holes and the second nozzle holes are staggered so that the sprays of the fuel ejected from the first nozzle holes and the second nozzle holes do no cross one another.

Abstract: A combustion system for direct injection diesel engines, having a fuel injection nozzle provided with upper and lower rows of nozzle holes and disposed so as to be opposed to a deep dish combustion chamber of a small opening ratio. The directions of the upper nozzle holes (1) in the upper row and those of the lower nozzle holes (2) in the lower row are set so that fuel injected from the upper nozzle holes (1) reaches a side wall of the combustion chamber and fuel injected from the lower nozzle holes (2) impinges upon a bottom surface (4) of the combustion chamber. A ratio of a fuel spray travel from the upper nozzle holes (1) to a diameter of each of the upper nozzle holes is set to 150-250. The number of said upper nozzle holes (1) is set twice as large as that of said lower nozzle holes (2).