Spark timing control system for an internal combustion engine

A spark timing control system for an internal combustion engine having a combustion chamber and engine coolant, comprising:

• (a) first means for sensing engine knocking and generating a knock signal indicative thereof;
• (b) second means for sensing an increase in the power output required of the engine and generating a power-increase signal indicative thereof;
• (c) third means for producing a spark in the combustion chamber at adjustable timing in terms of crank angle of the engine, the third means responsive to the knock signal for retarding the spark timing when knock occurs and advancing the spark timing when no knock occurs, the third means also responsive to the power-increase signal for retarding the spark timing when the increase in the power output is required of the engine;
• (d) fourth means for sensing the temperature of the engine coolant and generating a temperature signal indicative thereof;
• and
• (e) fifth means responsive to the temperature signal for selectively enabling and disabling the retardation of the spark timing due to the power increase in accordance with the temperature of the engine coolant.

A spark timing control system for an internal combustion engine having a combustion chamber, a throttle valve, and engine coolant, the system comprising:

• (a) an ignition device for producing a spark in the combustion chamber;
• (b) a power increase detector for sensing an increase in the power output required of the engine and generating an electrical pulse indicative thereof;
• (c) a control device connected to the ignition device for controlling timing of the production of the spark, the control device also connected to the power increase detector to receive the electrical pulse therefrom for retarding the spark timing in terms of crank angle of the engine when the increase in the power output is required of the engine;
• (d) a temperature switch responsive to the temperature of the engine coolant and disposed in the connection of the power increase detector to the control device for interrupting the feed of the electrical pulse from the power increase detector to the control device to suspend the retardation of the spark timing in accordance with the temperature of the engine coolant;
• and
• (e) said power increase detector including a throttle sensor for sensing an opening movement of the throttle valve and outputting a pulse train when the throttle valve is opened, an integrating circuit connected to the throttle sensor for integrating the pulse train therefrom and outputting a voltage signal, the level of which depends on the integrated value of the pulse train, and a comparator, connected at its first input terminal to the integrating circuit and supplied at its second input terminal with a reference voltage for comparing the voltage signal from the integrating circuit to the reference voltage, the integrating circuit operative to reduce the magnitude of the output signal thereof at a preset rate when receiving no pulse from the throttle sensor, the output terminal of the comparator connected to the control device through the temperature switch, whereby the comparator outputs a pulse when the throttle valve is moved in the valve opening direction to increase the engine power output.