Two-cycle engine with electronic fuel injection

A fuel injection system for a two-stroke cycle engine of the type comprising at least one cylinder, a crankcase associated with said cylinder, a piston reciprocally mounted in said cylinder and crankcase;

• a reciprocally openable and closable crankcase inlet for enabling combustible fluid to be drawn into the crankcase, a reciprocally openable and closable transfer port for transferring combustible fluid compressed in said crankcase to said cylinder, an ignition system for igniting compressed combustible fluid in said cylinder, a reciprocally openable and closable exhaust port in said cylinder for enabling exhaust of burned combustible fluid from said cylinder, a crankshaft connected to said piston of transferring mechanical energy from said piston to a drive unit, and an electrical energy supply for operating the ignition system and other electrical components, comprising:
• a) a fuel injector for injecting fuel to a manifold for combustion within said cylinder;
• b) a fuel pump for supplying fuel to said fuel injector;
• c) an air temperature sensor for providing a signal indicative of ambient air temperature;
• d) an engine speed sensor for providing a signal indicative of a speed of revolution of said engine;
• e) a timing sensor for providing a signal indicative of engine timing;
• f) a barometric pressure sensor for providing a signal indicative of atmospheric air pressure;
• g) a throttle position sensor for providing a signal indicative of an amount of opening of an engine throttle valve;
• h) an engine temperature sensor for providing a signal indicative of engine temperature;
• i) a look-up table of experimentally determined base fuel injection values at predetermined standard operating conditions is stored according to engine revolution speed and throttle valve opening amount of operating characteristics of a particular two-stroke cycle engine to be fuel-injected;
• and
• j) a processor executing a program performing the following functions:
• 1) turning said fuel pump on and off,
• 2) receiving the engine revolution speed signal and the throttle valve opening amount signal, and retrieving a corresponding base fuel injection value from said experimentally determined look-up table,
• 3) receiving the ambient air temperature signal and calculating an air temperature modification value of the base fuel injection value,
• 4) receiving the atmospheric air pressure signal and calculating a barometric pressure modification value of the base fuel injection value,
• 5) receiving the engine temperature signal and calculating an engine temperature modification value to the base fuel injection value,
• 6) determining a total fuel injection value from the base fuel injection value, the air temperature modification value, the barometric pressure modification value, and the engine temperature modification value,
• 7) determining, an injector open duration interval based upon the total fuel injection value and a known fuel output rate capacity of said fuel injector, and
• 8) generating a control signal for opening said fuel injector for the determined injector open duration interval in response to the engine timing signal;
• wherein the predetermined standard operating conditions include ambient air temperature, atmospheric air pressure, and engine temperature at the time the base fuel injection values are experimentally determined.

A fuel injection system for a two-stroke cycle engine of the type comprising at least one cylinder, a crankcase associated with said cylinder, a piston reciprocally mounted in said cylinder and crankcase;

• a reciprocally openable and closable crankcase inlet for enabling combustible fluid to be drawn into the crankcase, a reciprocally openable and closable transfer port for transferring combustible fluid compressed in said crankcase to said cylinder, an ignition system for igniting compressed combustible fluid in said cylinder, a reciprocally openable and closable exhaust port in said cylinder for enabling exhaust to burned combustible fluid from said cylinder, a crankshaft to said cylinder, an ignition system for igniting compressed combustible fluid in said cylinder, a reciprocally openable and closable exhaust port in said cylinder for enabling exhaust of burned combustible fluid from said cylinder, a crankshaft connected to said piston for transferring mechanical energy from said piston to a drive unit, and an electrical energy supply source for operating the ignition system and other electrical components, comprising:
• a) fuel injector for injecting fuel to a manifold for combustion within said cylinder;
• b) a fuel pump for supplying fuel to said fuel injector;
• c) an air temperature sensor for providing a signal indicative of ambient air temperature;
• d) an engine speed sensor for providing a signal indicative of a speed of revolution of said engine;
• e) a timing sensor for providing a signal indicative of engine timing;
• f) a barometric pressure for providing a signal indicative of atmospheric air pressure;
• g) a throttle position sensor for providing a signal indicative of an amount of opening of an engine throttle valve;
• h) an engine temperature sensor for providing a signal indicative of engine temperature;
• i) a look-up table of experimentally determined base fuel injection values at predetermined standard operating conditions is stored according to engine revolution speed and throttle valve opening amount for operating characteristics of a particular two-stroke cycle to be fuel-injected;
• and
• j) a processor executing a program performing the following functions:
• 1) turning said fuel pump on and off,
• 2) receiving the engine revolution speed signal and the throttle valve opening amount signal, and retrieving a corresponding base fuel injection value from said experimentally determined look-up table,
• 3) receiving the ambient air temperature signal and calculating an air temperature modification value of the base fuel injection value,
• 4) receiving the atmospheric air pressure signal and calculating an engine barometric pressure modification value of the base fuel injection value,
• 5) receiving the engine temperature signal and calculating an engine temperature modification value to the base fuel injection value,
• 6) determining a total fuel injection value from the base fuel injection value, the air temperature modification value, the barometric pressure modification value, and the engine temperature modification value,
• 7) determining an injector open duration interval based upon the total fuel injection value and a known fuel output rate capacity of said fuel injector, and
• 8) generating a control signal for opening said fuel injector for the determined injector open duration interval in response to the engine timing signal;
• wherein said processor program generates a priming control signal in response to the engine revolution speed signal and the throttle valve open amount signal.

A fuel injection system for a two-stroke cycle engine of the type comprising at least one cylinder, a crankcase associated with said cylinder, a piston reciprocally mounted in said cylinder and crankcase;

• a reciprocally openable and closable crankcase inlet for enabling combustible fluid to be drawn into the crankcase, a reciprocally openable and closable transfer port for transferring combustible fluid compressed in said crankcase to said cylinder, an ignition system for igniting compressed combustible fluid in said cylinder, a reciprocally openable and closable exhaust port in said cylinder for enabling exhaust of burned combustible fluid from said cylinder, a crankshaft connected to said piston for transferring mechanical energy from said piston to a drive unit, and an electrical energy supply source for operating the ignition system and other electrical components, comprising:
• a) fuel injector for injecting fuel to a manifold for combustion within said cylinder;
• b) a fuel pump for supplying fuel to said fuel injector;
• c) an air temperature sensor for providing a signal indicative of ambient air temperature;
• d) an engine speed sensor for providing a signal indicative of engine timing;
• e) a timing sensor for providing a signal indicative of engine timing;
• f) a barometric pressure sensor for providing a signal indicative of atmospheric air pressure;
• g) a throttle position sensor for providing a signal indicative of an amount of opening of an engine throttle valve;
• h) an engine temperature sensor for providing a signal indicative of engine temperature;
• i) a look-up table of experimentally determined base fuel injection values at predetermined standard operating conditions is stored according to engine revolution speed and throttle valve opening amount for operating characteristics of a particular two-stroke cycle engine to be fuel-injected;
• and
• j) a processor executing a program performing the following functions:
• 1) turning said fuel pump on and off,
• 2) receiving the engine revolution speed signal and the throttle valve opening amount signal, and retrieving a corresponding base fuel injection value from said experimentally determined look-up table,
• 3) receiving the ambient air temperature signal and calculating an air temperature modification value of the base fuel injection value,
• 4) receiving the atmospheric air pressure signal and calculating a barometric pressure modification value of the base fuel injection value,
• 5) receiving the engine temperature signal and calculating an engine temperature modification value to the base fuel injection value,
• 6) determining a total fuel injection value from the base fuel injection value, the air temperature modification value, the barometric pressure modification value, and the engine temperature modification value,
• 7) determining an injector open duration interval based upon the total fuel injection value and a known fuel output rate capacity of said fuel injector, and
• 8) generating a control signal for opening said fuel injector for he determined injector open duration interval in response to the engine timing signal;
• wherein said engine temperature sensor is an engine block temperature sensor.

A fuel injection system for a two-stroke cycle engine of the type comprising at least one cylinder, a crankcase associated with said cylinder, a piston reciprocally mounted in said cylinder and crankcase;

• a reciprocally openable and closable crankcase inlet for enabling combustible fluid to be drawn into the crankcase, a reciprocally openable and closable transferring combustible fluid compressed combustible fluid in said cylinder, a reciprocally openable and closable exhaust port in said cylinder for enabling exhaust of burned combustible fluid from said cylinder, a crankshaft connected to said piston for transferring mechanical energy from said piston to a drive unit, and an electrical energy supply source for operating the ignition system and other electrical components, comprising:
• a) fuel injector for injecting fuel to a manifold for combustion within said cylinder;
• b) a fuel pump for supplying fuel to said fuel injector;
• c) an air temperature sensor for providing a signal indicative of ambient air temperature;
• d) an engine speed sensor for providing a signal indicative of a speed of revolution of said engine;
• e) a timing sensor for providing a signal indicative of engine timing;
• f) a barometric pressure sensor for providing a signal indicative of atmospheric air pressure;
• g) a throttle position sensor for providing a signal indicative of an amount of opening of an engine throttle valve;
• h) an engine temperature sensor for providing a signal indicative of engine temperature;
• i) a look-up table of experimentally determined base fuel injection values at predetermined standard operating conditions is stored according to engine revolution speed and throttle valve opening amount for operating characteristics of a particular two-stroke cycle engine to be fuel-injected;
• and
• j) a processor executing a program performing the following functions:
• 1) turning said fuel pump on and off,
• 2) receiving the engine revolution speed signal and the throttle valve opening amount signal, and retrieving a corresponding base fuel injection value from said experimentally determined look-up table,
• 3) receiving the ambient air temperature signal and calculating an air temperature modification value of the base fuel injection value,
• 4) receiving the atmospheric air pressure signal and calculating a barometric pressure modification value of the base fuel injection value,
• 5) receiving the engine temperature signal and calculating and engine temperature modification value to the base fuel injection value,
• 6) determining a total fuel injection value from the base fuel injection value, the air temperature modification value, the barometric pressure modification value, and the engine temperature modification value,
• 7) determining an injector open duration interval based upon the total fuel injection value and a known fuel output rate capacity of said fuel injector, and
• 8) generating a control signal for opening said fuel injector for the determined injector open duration interval in response to the engine timing signal;
• and
• k) a voltage sensor for providing a signal indicative of voltage, and wherein said processor receives the voltage signal.