Method of injecting fuel into the combustion chambers of an internal combustion engine, and fuel injection system for said engine

Fuel injection system for an internal-combustion engine, including a diesel engine, which contains a number of fuel injectors each comprising an injection valve and a common feed and storage line which supplies the individual fuel injectors with highly pressurized fuel and itself is acted upon by highly pressurized fuel by way of a high-pressure pump, as well as two high-pressure reservoirs which are, in each case, provided in the high-pressure lines leading to the fuel injectors and have a defined fuel storage volume, the beginning and end of the injection of the fuel into the combustion chambers being controlled by opening and closing the injection valves of the fuel injectors,

• wherein the fuel storage volume of the high-pressure reservoirs and the flow resistance of the high-pressure lines leading from the common feed and storage line to the high-pressure reservoirs, while taking into account the maximal injection quantity and duration, are dimensioned such that, during the injection, a lowering of the fuel pressure existing in the fuel injector takes place from an initial pressure p1, which is slightly lower than the system pressure, to a fuel pressure p2 at a second point in time when the closing of the injection valve starts, so that the pressure, which rises as a result of the ram pressure during the closing of the injection valve at the end of the injection in the fuel injector, does not exceed a defined value.

A fuel injection system assembly for an internal combustion engine comprising:

• a plurality of fuel injection valves,
• a common feed line operable to supply highly pressurized fuel at a system pressure, and
• high pressure lines leading from the common feed line to respective ones of the fuel injection valves,
• wherein the fuel storage volume and flow resistance of the system intermediate the common feed line and the fuel injection valves are configured such that, during injection, a lowering of the fuel pressure in the fuel injector from an initial pressure which is slightly lower than the system pressure to a second fuel pressure at a later point in time when closing of the injector valve starts, such that the injector valve pressure which rises as a result of ram pressure during the closing of the injection valve at the end of injection does not exceed a predetermined value.

A method of supplying fuel to an internal combustion engine using a fuel injection system assembly comprising:

• a plurality of fuel injection valves,
• a common feed line operable to supply highly pressurized fuel at a system pressure, and
• high pressure lines leading from the common feed line to respective ones of the fuel injection valves,
• said method comprising
• controlling the fuel pressure at the injection valves such that during injection, a lowering of the fuel pressure in the fuel injector from an initial pressure which is slightly lower than the system pressure to a second fuel pressure at a later point in time when closing of the injector valve starts, such that the injector valve pressure which rises as a result of ram pressure during the closing of the injection valve at the end of injection does not exceed a predetermined value.