Fuel injection strategies in opposed-piston engines with multiple fuel injectors
View Patent ↗In an opposed-piston engine, two or more fuel injectors are mounted to a cylinder for direct side injection into the cylinder. The injectors are controlled so as to inject either a single fuel pulse or a plurality of fuel pulses per cycle of engine operation in order to initiate combustion during varying engine speeds and operating conditions.
1. A fuel injection means for injecting fuel into a cylinder of an opposed-piston engine, including:
two fuel injectors disposed for direct side injection of fuel into a combustion chamber defined between end surfaces of a pair of opposed pistons as the pair of opposed pistons approach top dead center locations in the cylinder;
engine control means responsive to engine operating conditions for generating output control signals; and,
an injector driver responsive to the output control signals for generating first fuel injector actuation signals operative to cause a first fuel injector of the two fuel injectors to emit a first split injection including a pilot injection followed by a main injection and second fuel injector actuation signals operative to cause a second fuel injector of the two fuel injectors to emit a second split injection including a pilot injection followed by a main injection independently of the first fuel injector;
wherein the first fuel injector actuation signals are constrained by a minimum time interval occurring between successive first fuel injector actuation signals;
wherein the second fuel injector actuation signals are constrained by the minimum time interval occurring between successive second fuel injector actuation signals;
wherein the fuel injector actuation signals impose a time interval separating each pilot injection from its following main injection.
2. The fuel injection means of claim 1 , wherein the first and second split injections overlap.
3. The fuel injection means of claim 1 , wherein the injector driver is further responsive to the output control signals to cause each of the first and second fuel injectors to emit a single injection.
4. A fuel injection system for an opposed-piston engine, comprising:
a first fuel injector and a second fuel injector, each disposed for direct side injection of fuel through a sidewall of a cylinder of the opposed-piston engine into a combustion chamber defined in the cylinder between end surfaces of a pair of opposed pistons as the pair of opposed pistons approach top dead center locations in the cylinder;
an engine control unit responsive to engine operating conditions for generating output control signals; and,
an injector driver responsive to the output control signals for generating fuel injector actuation signals operative to cause the first fuel injector to emit a first split injection and to cause the second fuel injector to emit a second split injection independently of the first fuel injector;
wherein each of the first and second split injections comprises a pilot injection followed by a main injection;
wherein the fuel injector actuation signals impose a minimum time interval separating each pilot injection from its following main injection.
5. The fuel injection system of claim 4 , wherein the first and second split injections overlap.
6. The fuel injection system of claim 4 , wherein the pilot injection of the first split injection is offset from the pilot injection of the second split injection by an amount of time less than the minimum time interval.
7. The fuel injection system of claim 4 , wherein the injector driver is further responsive to the output control signals to cause each of the first and second fuel injectors to emit a single injection.