Abstract:
Embodiments for starting an engine are provided. In one embodiment, an engine control method comprises, during engine cranking, commencing fuel injection when intake manifold pressure drops below a threshold, the threshold based on fuel volatility. In this way, the stability of engine starts using low volatility fuels may be increased.
Abstract:
A compressor active surge control system that includes an air recirculation line that has a first end connected downstream of a compressor outlet and a second end connected upstream of a compressor inlet. The gas recirculation line recirculates compressed air from the compressor outlet to the compressor inlet. Also included in the system is a mixer positioned to receive both ambient air and recirculated air. Mixing of the air homogenizes the air prior to its introduction into the compressor. An air cooler may be included that cools the recirculated air prior to its introduction into the compressor. Cooling and mixing of the recirculated air expands the operating range of the compressor by reducing the incidence of surge. Various existing components, such as intercoolers and filters, may serve the additional duty of cooling or mixing the recirculated air.
Abstract:
Intake air is severely restricted during cold start of a diesel engine to provide high engine-out exhaust gas temperatures and quickly heat exhaust treatment devices. Cylinder pressures are maintained substantially below the pressure of the ambient atmosphere during a principal portion of the intake stroke of each combustion cycle to promote rapid fuel vaporization and higher combustion temperatures. The engine is operated in a premixed charge compression ignition combustion mode to provide a high engine-out exhaust temperature, stable combustion, and low emissions during the cold start period.
Abstract:
An engine, having an intake passage, a throttle valve arranged in the intake passage, and a fuel injector arranged in the intake passage for injecting fuel into the intake passage, comprises an air-flow control valve arranged in the intake passage between the fuel injector and the throttle valve. The air-flow control valve is controlled to close during the engine starting operation, and to open after the engine starting operation completes. The air-flow control valve has a valve element having an axis about which the element is rotatable when the valve is opened or closed. The rotational direction of the valve element is selected so that air flowing through the valve is guided by the valve toward the fuel injector when the air-flow control valve is controlled to an intermediate open position which is between the closed position and the full open position.
Abstract:
An engine system and method for improving engine starting are disclosed. In one example, engine port throttles are adjusted to improve fuel vaporization of a fuel that includes alcohol. The system and method may improve engine starting and emissions.
Abstract:
An engine system and method for improving engine starting are disclosed. In one example, engine port throttles are adjusted to improve fuel vaporization of a fuel that includes alcohol. The system and method may improve engine starting and emissions.
Abstract:
An internal combustion engine's start-up torsional disturbances are reduced by drawing down intake manifold pressure prior to engine cranking. In a preferred arrangement, a secondary air injection reaction pump is adapted for evacuating the intake manifold to effect the desired draw down of the intake manifold pressure.
Abstract:
An internal combustion engine's start-up torsional disturbances are reduced by drawing down intake manifold pressure prior to engine cranking. In a preferred arrangement, a secondary air injection reaction pump is adapted for evacuating the intake manifold to effect the desired draw down of the intake manifold pressure.
Abstract:
A apparatus and method for adjusting the amount of air introduced into a cylinder of an internal combustion engine. An intake passage is connected to the cylinder for introducing air. An intake valve is provided in the intake passage for cyclically opening and closing the cylinder. An injector is provided in the intake passage for injecting fuel. A throttle valve is positioned in the intake passage for adjusting an amount of air flow into the cylinder. An electronic control unit (ECU) controls the position of the throttle valve. The ECU closes the intake passage to decrease the pressure in the intake passage when cranking is started. The ECU moves the throttle valve to a first open position .theta.2 to increase the amount of air introduced into the cylinder after a predetermined time period elapses from the start of engine cranking. The ECU moves the throttle valve to an open position .theta.1 when the engine starts.
Abstract:
An engine, having an intake passage, a throttle valve arranged in the intake passage, and a fuel injector arranged in the intake passage for injecting fuel into the intake passage, comprises an air-flow control valve arranged in the intake passage between the fuel injector and the throttle valve. The air-flow control valve is controlled to close during the engine starting operation, and to open after the engine starting operation completes. The air-flow control valve has a valve element having an axis about which the element is rotatable when the valve is opened or closed. The rotational direction of the valve element is selected so that air flowing through the valve is guided by the valve toward the fuel injector when the air-flow control valve is controlled to an intermediate open position which is between the closed position and the full open position.