Internal combustion engine with initial ignition suppression during cranking
AssigneeGeneral Motors Corporation
InventorEarl H. Buetemeister
Life of this patent
Estimating the term…
Abstract
A spark ignited internal combustion engine includes a counter which counts a predetermined number of the initial ignition signals during engine start and suppresses those ignition signals to prevent reverse torque due to excessive cylinder pressure before top dead center at the extra-low engine speed of initial start and thus assist engine start, especially in a warm engine. The counter is reset by detection of the closure of the ignition switch through the electric power supply line so that no separate wire from the start switch or motor is required.
Claims3
In a multi-cylinder internal combustion engine having a rotating crankshaft, a piston in each of the cylinders coupled to the crankshaft in rotational driving relationship, means effective to deliver fuel charges to the respective cylinders at predetermined times, means effective to normally ignite the fuel charges in the respective cylinders in response to ignition signals at predetermined times in advance of top dead center in the respective cylinders and means effective to start the engine by independent rotation of the crankshaft, the improvement comprising:
- counting means effective during initial actuation of the engine start means to count a predetermined number of said ignition signals;
- means effective, while the counting means is counting, to prevent ignition in the respective cylinders, whereby crankshaft rotational speed is allowed to increase without reverse torque due to ignition cylinder pressure buildup before top dead center;
- and
- means responsive to the counting means reaching the predetermined count to restore ignition in the respective cylinders, whereby the pistons are enabled to drive the crankshaft after crankshaft rotational speed is sufficient to maintain engine operation with ignition events before top dead center.
In a multi-cylinder internal combustion engine having a rotating crankshaft, a piston in each of the cylinders coupled to the crankshaft in rotational driving relationship, means effective to deliver fuel charges to the respective cylinders at predetermined times, means effective to normally ignite the fuel charges in the respective cylinders in response to ignition signals at predetermined times in advance of top dead center in the respective cylinders, electric power means including an ignition switch and means effective to start the engine by independent rotation of the crankshaft, the improvement comprising:
- counting means effective when reset to count an initial predetermined number of said ignition signals during initial activation of the engine start means after said reset;
- means responsive to initial closure of the ignition switch to reset the counting means;
- means effective, while the counting means is counting, to prevent ignition in the respective cylinders, whereby crankshaft rotational speed is allowed to increase without reverse torque due to ignition cylinder pressure buildup before top dead center;
- and
- means responsive to the counting means reaching the predetermined count to restore ignition in the respective cylinders, whereby the pistons are enabled to drive the crankshaft after crankshaft rotational speed is sufficient to maintain engine operation with ignition events before top dead center.
In a multi-cylinder internal combustion engine having a rotating crankshaft, a piston in each of the cylinders coupled to the crankshaft in rotational driving relationship, means effective to deliver fuel charges to the respective cylinders at predetermined times, means effective to normally ignite the fuel charges in the respective cylinders in response to ignition signals at predetermined times in advance of top dead center in the respective cylinders, electric power means including an ignition switch and means effective to start the engine by independent rotation of the crankshaft, the improvement comprising:
- an RC differentiator circuit effective to generate a reset signal upon closure of the ignition switch;
- a counter responsive to said reset signal to generate a first output and count ignition signals upon initial activation of the engine start means after said closure of the ignition switch, said counter being effective to generate a second output upon counting a predetermined number of said ignition signals;
- logic means effective to receive the ignition signals and counter output and suppress the ignition signals when the first counter output is present and pass the ignition signals when the second counter output signal is present;
- and
- means effective to provide the ignition signals, when not suppressed, from the logic means to the ignition means to ignite the fuel charges.
Dependencies are inferred from the claim text.