Abstract: A fuel injection device that injects a liquefied gas fuel from an injection port to a combustion chamber of the internal combustion engine includes a passage forming member configured to define a fuel passage through which the liquefied gas fuel flows to the injection port, a temperature regulating unit configured to adjust a temperature of the liquefied gas fuel flowing through the fuel passage according to an operation state of the internal combustion engine, and a pressure regulating unit configured to adjust a pressure of the liquefied gas fuel flowing through the fuel passage according to the operation state of the internal combustion engine.

Abstract: A fuel injection device that injects a liquefied gas fuel from an injection port to a combustion chamber of the internal combustion engine includes a passage forming member configured to define a fuel passage through which the liquefied gas fuel flows to the injection port, a temperature regulating unit configured to adjust a temperature of the liquefied gas fuel flowing through the fuel passage according to an operation state of the internal combustion engine, and a pressure regulating unit configured to adjust a pressure of the liquefied gas fuel flowing through the fuel passage according to the operation state of the internal combustion engine.

Abstract: A variable-valve-mechanism controlling portion controls a variable valve mechanism in such a manner that an exhaust valve is opened not only in an exhaust stroke but also in an intake stroke. In the intake stroke, a part of the exhaust gas discharged from the combustion chamber is returned to the combustion chamber along with an intake air flowing through the intake passage. A fluid injector injects a non-combustible fluid including water into the exhaust gas discharged from the combustion chamber. In the intake stroke, the exhaust gas introduced into the combustion chamber from the exhaust passage contains a water vapor evaporated from the non-combustible fluid. The exhaust gas discharged from the combustion chamber in the exhaust stroke includes the non-combustible fluid and is returned to the combustion chamber in a successive intake stroke.

Abstract: A control system for a combustion system is applied to a combustion system which has a fuel injector injecting a fuel directly into a combustion chamber and a water injector injecting water (non-combustible fluid) into the combustion chamber. When a combustion engine operates at high load, the water collides with a fuel spray which the fuel injector injects. When a combustion engine operates at low-load, the water injection starts before the fuel injection and the water injection terminates before the fuel injection starts. Thus, the misfire can be avoided and NOx can be decreased by water injection at low-load operation of a combustion engine.

Abstract: A combustion system of an internal combustion engine has a fuel injector injecting a fuel directly into a combustion chamber and a water injector injecting a water (non-combustible fluid) into the combustion chamber. The water collides with a fuel spray which the fuel injector injects. A penetrating force of the fuel spray is decreased and the fuel spray hardly reaches a cylinder wall surface. The injected fuel is combusted at a position away from the cylinder wall surface, so that the combustion heat transferred to the cylinder wall surface is reduced and the heat loss of the combustion can be decreased.