Fuel injection system for an internal combustion engine

Abstract

In a fuel injection system, as an engine crankshaft rotates twice, a working chamber contracts and expands a number of times equal to twice the number of engine combustion chambers. Each time the working chamber expands, fuel is conducted to the working chamber. During alternate contractions of the working chamber, fuel is directed from the working chamber toward each of the combustion chambers in sequence to be injected thereinto at a first timing. During the intervening contractions of the working chamber, fuel is directed from the working chamber toward each of the combustion chambers in sequence to be injected thereinto at a second timing. The second timing follows the first timing by a fraction of at least one operating stroke of the engine. In another fuel injection system of this invention, fuel is periodically injected into an engine combustion chamber at a first timing with respect to rotation of the engine crankshaft. Fuel is also periodically injected into the combustion chamber at a second timing with respect to rotation of the crankshaft. The quantity of fuel injected at the first timing increases to a preset maximum level as the quantity of fuel injected at the second timing increases to a predetermined level. The first timing fuel quantity remains at the preset maximum level as the second timing fuel quantity increases from the predetermined level.