摘要:
An engine cooling system and method that will allow an engine cooling fan to be driven independently of the engine speed. The engine cooling fan is driven by the engine crankshaft, but includes an electronically controllable fan clutch between the fan and the crankshaft. A control module electronically controls the engagement of the fan clutch based upon engine and vehicle operating conditions. A water pump for pumping coolant through the engine cooling system may also be driven by the crankshaft of the engine, but with an electronically controlled pump clutch between the engine crankshaft and the water pump.
摘要:
An engine cooling system and method that will allow an engine water pump to be driven independently of the engine speed. The engine water pump is driven by the engine crankshaft, but includes an electronically controllable pump clutch between the water pump and the crankshaft. A control module electronically controls the engagement of the pump clutch based upon engine and vehicle operating conditions.
摘要:
A rotary valve provides single point flow control of coolant within the cooling system of an internal combustion engine. The valve distributes coolant flow from the engine in predetermined flow modes to either 1) the radiator and heater simultaneously, 2) a bypass circuit only, 3) the heater only, or 4) the radiator and bypass simultaneously. The single-point coolant control results in advantages of shorter warm-up times, a lower pressure drop (reducing power consumption by the pump), reduced engine emissions and fuel consumption, improved cabin heater performance, and improved engine durability due to reduced thermal shocks to the engine components by virtue of more precise control of engine operating temperature.
摘要:
A method and a speed control system for controlling a speed of a vehicle utilizes a speed sensor for sensing a speed of the vehicle and generating a corresponding speed signal. A control unit determines one of a quick or slow acceleration status of the vehicle based on the speed signal. The control unit also determines a mode of operation of the speed control system and filters the speed signal based on the acceleration status and the mode of operation of the speed control system. The speed of the vehicle is then controlled based on the filtered speed signal.
摘要:
A method and system for accurately controlling a position of a servo motor in a vehicle speed control system for various operation conditions includes predetermined parameters of a polynomial which define desired positions of a servo motor for various vehicle speeds under normal operation conditions. A sensor senses a speed of the vehicle and generates a corresponding speed signal. A controller determines an initial desired position of servo motor based on the speed signal. The controller also determines whether the operation condition of the vehicle has deviated from the normal operation condition, and if so, determines a revised desired position of the servo motor based on the actual position of the servo motor and the initial desired position of the servo motor. Finally, the controller controls the servo motor based on the revised desired position of the servo motor.
摘要:
A fuel delivery system is provided with a fuel solenoid valve to minimize fuel leakage and evaporative emissions during diurnal cycles by preventing pressure buildup as the temperature of the fuel system rises. The fuel solenoid valve is located between a pressurized side of the delivery system and a fuel tank. In one embodiment, the fuel solenoid valve is closed when the engine is running or when the engine is off and the rail is hot. When the fuel rail cools down, the solenoid valve opens to bleed a desired amount of fuel thereby creating a fuel vapor space. Thereafter, during hot soak conditions of the diurnal cycles when the fuel rail is hot again while the engine is off, the pressure will rise due to the thermal expansion of the fuel and the created fuel vapor space minimizes further rising of the fuel pressure. Further, by adjusting the solenoid valve opening time, the pressure rising limit may be set at a desired pressure to minimize injector leakage.
摘要:
A system for controlling idle air flow for an engine. The system includes an idle air control valve, a stepper motor, and a controller. The idle air control valve has a first hard stop and a second hard stop. The stepper motor is coupled to the idle air control valve and configured to manipulate the position of the idle air control valve. The controller is in communication with the stepper motor to provide a driving signal. Further, the controller is configured to drive the idle air control valve to the first hard stop and then drive the idle air control valve to the second hard stop after receiving an engine shutdown command.