Abstract: Fuel injection accuracy of gaseous fuel injectors is important for efficient engine operation. However, the performance of the injectors varies from part to part and across their lifetime, and when an injector is under performing according to its specification it is often unknown what is causing the problem. An apparatus for operating a gaseous fuel injector in an engine comprises a mass flow sensor that generates a signal representative of the mass flow rate of the gaseous fuel in a supply conduit in the engine.

Abstract: Fuel injection accuracy of gaseous fuel injectors is important for efficient engine operation. However, the performance of the injectors varies from part to part and across their lifetime, and when an injector is under performing according to its specification it is often unknown what is causing the problem. An apparatus for operating a gaseous fuel injector in an engine comprises a mass flow sensor that generates a signal representative of the mass flow rate of the gaseous fuel in a supply conduit in the engine.

Abstract: A flexible-fuel internal combustion engine apparatus comprises a combustion chamber, an intake valve, a first fuel injector, a second fuel injector, and a computer. The intake valve is operable to admit an intake charge into the combustion chamber. The first fuel injector injects a gaseous fuel directly into the combustion chamber. The second fuel injector injects a liquid fuel into the intake charge upstream of the intake valve. The computer is operatively connected with the first fuel injector and the second fuel injector to actuate injection of fuel respectively therefrom. The computer is programmed to command a gaseous-to-liquid fuel ratio as a function of at least one operating parameter from a group comprising gaseous fuel pressure, gaseous fuel mass, engine speed, engine torque, inlet air temperature, inlet air humidity, knock detection, operating history, torque command, and emissions.

Abstract: A method and apparatus are disclosed for introducing a gaseous fuel into a combustion chamber of an internal combustion engine. The method includes dividing the engine map into three distinct operating regions, with different operating modes in each region. When the engine is operating in a low load region, gaseous fuel is introduced to the combustion chamber during an intake stroke before an intake valve associated with the combustion chamber closes. When the engine is operating in a high load low-speed region, gaseous fuel is directly injected into the combustion chamber during a compression stroke after the intake valve is closed. When the engine is operating in a high load high-speed region, a split injection strategy is employed with a first portion of the gaseous fuel introduced into the charge before the intake valve closes and a second portion being injected after the intake valve is closed.

Abstract: A method and apparatus are disclosed for introducing a gaseous fuel into a combustion chamber of an internal combustion engine. The method includes dividing the engine map into three distinct operating regions, with different operating modes in each region. When the engine is operating in a low load region, gaseous fuel is introduced to the combustion chamber during an intake stroke before an intake valve associated with the combustion chamber closes. When the engine is operating in a high load low-speed region, gaseous fuel is directly injected into the combustion chamber during a compression stroke after the intake valve is closed. When the engine is operating in a high load high-speed region, a split injection strategy is employed with a first portion of the gaseous fuel introduced into the charge before the intake valve closes and a second portion being injected after the intake valve is closed.

Abstract: A flexible-fuel internal combustion engine apparatus comprises a combustion chamber, an intake valve, a first fuel injector, a second fuel injector, and a computer. The intake valve is operable to admit an intake charge into the combustion chamber. The first fuel injector injects a gaseous fuel directly into the combustion chamber. The second fuel injector injects a liquid fuel into the intake charge upstream of the intake valve. The computer is operatively connected with the first fuel injector and the second fuel injector to actuate injection of fuel respectively therefrom. The computer is programmed to command a gaseous-to-liquid fuel ratio as a function of at least one operating parameter from a group comprising gaseous fuel pressure, gaseous fuel mass, engine speed, engine torque, inlet air temperature, inlet air humidity, knock detection, operating history, torque command, and emissions.

Abstract: In a gaseous-fuelled stoichiometric compression ignition internal combustion engine, a pilot fuel is injected directly into the combustion chamber to help initiate a multi-point ignition. The engine provides performance improvements approaching those of high pressure direct injection engines but with less complexity because the gaseous fuel is introduced into the intake air subsystem at relatively low pressure and as a result of the stoichiometric combustion, the low oxygen content in the combustion products exiting the combustion chamber allows the use of a three-way catalyst instead of other after treatment arrangements normally associated with conventional compression ignition engines that require the addition of a reductant.

Abstract: A glow member, preferably in the shape of a ring, assists ignition and combustion of a fuel used in an internal combustion engine. A fuel injection valve injects a plurality of fuel jets directly into a combustion chamber during operation of the engine so that the fuel jets are aimed to the proximity of the glow member such that ignition of fuel in each fuel jet is assisted by the glow member. The glow member is made from high temperature materials and can include catalytic materials to further promote combustion. The glow member can be actively heated, for example by an electric current, in addition to being passively heated by the heat generated within the combustion chamber by the combustion of the fuel therein.

Abstract: A directly actuated injection valve comprises a hollow valve housing, a valve member disposed within the hollow interior, a biasing mechanism, an actuator assembly and a passive hydraulic link assembly. The valve member is movable between a closed position and an open position for governing the flow of fuel into the combustion chamber of an internal combustion engine. The biasing mechanism, preferably a spring, biases the valve member in the closed position. The actuator assembly generates an opening force that acts against the valve spring to open the valve. The hydraulic link assembly is interposed between the valve member and the valve spring and the actuator assembly. The hydraulic link assembly transmits respective closing and opening forces to the valve member. The hydraulic link preferably comprises a piston disposed within a cylinder that is filled with a hydraulic fluid.

Abstract: A directly actuated injection valve comprises a hollow valve housing, a valve member disposed within the hollow interior, a biasing mechanism, an actuator assembly and a hydraulic link assembly. The valve member is movable between a closed position and an open position for governing the flow of fuel into the combustion chamber of an internal combustion engine. The biasing mechanism, preferably a spring, biases the valve member in the closed position. The actuator assembly generates an opening force that acts against the valve spring to open the valve. The hydraulic link assembly is interposed between the valve member and the valve spring and the actuator assembly. The hydraulic link assembly transmits respective closing and opening forces to the valve member. The hydraulic link preferably comprises a piston disposed within a cylinder that is filled with a hydraulic fluid.

Abstract: A directly actuated injection valve comprises a hollow valve housing, a valve needle disposed within the hollow interior, a needle spring, an actuator assembly, and a hydraulic link assembly. The valve needle is movable between a closed position and an open position for governing the flow of fuel into the combustion chamber of an internal combustion engine. The displacement of the valve needle from the closed position is defined as the lift. The a needle spring biases the valve needle in the closed position. The actuator assembly generates an opening force that acts against the needle spring to open the valve. The hydraulic link assembly is interposed between the valve needle and the needle spring and the actuator assembly. The hydraulic link assembly transmits respective closing and opening forces to the valve needle. The hydraulic link preferably comprises a piston disposed within a cylinder that is filled with a hydraulic fluid.

Abstract: A dual fuel, natural gas/diesel two-stroke engine includes a cylinder and a piston in the cylinder, and inlet ports around the cylinder which are uncovered by downward movement of the piston. A blower forces air through the inlet ports when the latter is uncovered, and the engine includes an exhaust port and valve for exhausting combustion gases once each cycle. Diesel injection takes place near top dead center to ignite the gaseous mixture. An injector is provided for injecting natural gas into the cylinder once each cycle, including a delivery conduit which opens into the cylinder at a location above the inlet ports for air, such that the piston when descending completely uncovers the conduit before beginning to uncover the air inlet ports.