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US 5,329,908 AGranted
Compressed natural gas injection system for gaseous fueled engines
AssigneeCummins Engine Company, Inc.
InventorsYul J. Tarr, Julius P. Perr
Life of this patent
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AssigneeCummins Engine Company, Inc.
InventorsYul J. Tarr, Julius P. Perr
Estimating the term…
In accordance with preferred embodiments, a fuel injector has a gas accumulator of a volume that is at least ten times the maximum amount of fuel which would have to be injectable thereby, and a solenoid operated poppet valve with an end face that opens into the combustion cylinder and is shaped to deflect a portion of the fuel injected into direct contact with the ignition plug. In a first embodiment, using a variable fuel supply, an electronic control unit (ECU) controls the injection timing to inject the compressed gas into the cylinders as each's piston nears its top dead center (TDC) position to obtain diesel engine-like efficiencies (.eta.=45%) so long as the compressed gas supply pressure is sufficiently high (at least approximately 2,000 psi), and when the compressed gas supply pressure becomes too low for high efficiency operation (i.e., below 2,000 psi), the ECU changes the manner of operation so that fuel is injected into the engine when piston is near its bottom dead center position (BDC) so that it can be premixed with air prior to ignition to produce gasoline engine-like efficiencies (.eta.=35%).
Compressed gas injection system for gaseous fueled engines, comprising a gas supply containing a compressed fuel gas in a gaseous state, at least one fuel injector for injecting a variable quantity of gaseous fuel into an engine cylinder, a supply line means for enabling the compressed fuel gas to flow said supply of compressed fuel gas to said at least one fuel injector, said fuel gas being at a pressure above at least approximately 2,000 psi for at least a portion of the total contents of the gas supply, and an electronic control means for controlling both the quantity fuel gas injected into the engine cylinder by said fuel injector and the time at which it is injected relative to a cycle of operation of the engine cylinder as a function of monitored gas pressure and engine operating parameters, said time being from between about 20.degree. before to about 10.degree. after said piston reaches a top dead center position whenever said fuel gas pressure is above at least approximately 2,000 psi.
Dependencies are inferred from the claim text.