Ignition timing control for marine engine
First Claim
1. A method of controlling ignition firing timing of an ignition element associated with an engine, the engine including an intake system having at least one throttle valve and a cooling system containing coolant, the method involving sensing coolant temperature and an opening degree of the throttle valve, determining engine speed, determining ignition timing based upon the determined engine speed and the sensed throttle valve opening degree, detecting a low-temperature idle state of the engine based upon the sensed coolant temperature, and compensating the ignition timing by advancing or delaying the determined ignition timing while the engine is in the low temperature idle state such that the sensed engine speed generally matches a preset target engine speed corresponding to the sensed coolant temperature.
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Abstract
The present invention is an ignition control system controlling ignition firing timing of an ignition element associated with an engine. The engine includes an output shaft powering a water propulsion device, an intake system including a throttle valve, and a sensor providing an output signal corresponding to each revolution of the output shaft. The ignition control system calculates a base ignition firing timing from a time between successive previous output signals, and determines if a low-temperature idle condition of engine exists from the sensed throttle angle and coolant temperature. If such condition exists, the ignition control system also determines a compensation value to compensate ignition timing to either the advance or delay side to generally match a target engine speed for a given coolant temperature, and modifies the basic ignition firing timing by the compensation value.
26 Citations
21 Claims
- 1. A method of controlling ignition firing timing of an ignition element associated with an engine, the engine including an intake system having at least one throttle valve and a cooling system containing coolant, the method involving sensing coolant temperature and an opening degree of the throttle valve, determining engine speed, determining ignition timing based upon the determined engine speed and the sensed throttle valve opening degree, detecting a low-temperature idle state of the engine based upon the sensed coolant temperature, and compensating the ignition timing by advancing or delaying the determined ignition timing while the engine is in the low temperature idle state such that the sensed engine speed generally matches a preset target engine speed corresponding to the sensed coolant temperature.
- 9. A control system for controlling ignition firing of an engine ignition element, the engine including an air intake system having at least one throttle valve and a cooling system containing coolant, said control system comprising an engine speed detector, a crankshaft angle detector, a coolant temperature sensor, an ignition timing controller connected to the crankshaft angle detector and the engine speed detector so as to receive signals therefore indicative of a crankshaft angle of the engine and engine rotational speed, respectively, said ignition timing controller outputting an ignition timing signal, and an ignition timing compensation controller connected to the coolant temperature sensor and to the engine speed detector to receive signals therefrom indicative of the coolant temperature and the engine speed, the ignition timing compensation controller outputting a warm-up ignition timing compensation signal that selectively combines with the timing signal output from the ignition timing controller to produce an adjusted timing signal.
- 16. An control system for controlling ignition firing of an engine ignition element, the engine including an air intake system having at least one throttle valve and a cooling system containing coolant, said control system comprising an engine state detection means for detecting whether the engine is accelerating, an ignition control means for determining a basic ignition timing based upon a determined operational state of the engine as detected by the engine state detection means, a low-temperature idle condition detection means for detecting a low temperature idle condition based upon coolant temperature and the operational state of the engine as detected by the engine state detection means, and compensation means for compensating the basic ignition timing to an advance or delay side while the engine is in the low-temperature idle condition so as to approximate a preset target engine speed that corresponds to coolant temperature.
- 19. A method of controlling ignition firing timing of an ignition element associated with an engine, the engine including an intake system having at least one throttle valve and a cooling system containing coolant, the method involving sensing coolant temperature and an opening degree of the throttle valve, determining engine speed, determining ignition timing based upon the determined engine speed and the sensed throttle valve opening degree, detecting a low-temperature idle state of the engine based upon the sensed coolant temperature, and determining a target engine speed based on the sensed coolant temperature, comparing the target engine speed with the sensed engine speed to determine a required change in engine speed to match the target engine speed, determining a warm-up control compensation value for ignition timing based upon the determined required change in engine speed, and adjusting the determined ignition timing by the warm-up control compensation value for ignition timing such that the ignition timing is compensated to an advance or delay side while the engine is in the low-temperature idle state so as to adjust engine speed to generally match a preset target engine speed corresponding to the sensed coolant temperature.
Specification