Patent ID: 6470852
Filing Date: 2002-10-29
Classification: F02B,F02D

Abstract:
An internal combustion engine comprising a cylinder body defining at least one cylinder bore in which a piston reciprocates to rotate a crankshaft, a cylinder head affixed to an end of the cylinder body and defining a combustion chamber with the cylinder bore and the piston, an air induction system arranged to introduce air to the combustion chamber, the air induction system including a main passage, a throttle valve movable within the main passage between an open position and a closed position to regulate air flow through the main passage, an idle passage bypassing the throttle valve, and an idle valve movable within the idle passage between an open position and a closed position to regulate air flow through the idle passage, a fuel supply system arranged to supply fuel to the combustion chamber, an ignition system arranged to fire an air/fuel charge within the combustion chamber, a throttle valve position sensor arranged to sense that the throttle valve is generally placed in the closed position, an engine speed sensor arranged to sense a rotational speed of the crankshaft, and a control device connected with the sensors, the idle valve and the ignition system, the control device being configured to practice one of slow down controls comprising bringing the idle valve to the closed position, retarding ignitions by the ignition system and thinning out a certain number of ignitions by the ignition system to slow down the rotational speed of the crankshaft based upon a throttle position signal from the throttle valve position sensor and an engine speed signal from the engine speed sensor when the throttle position signal indicates that the throttle valve is generally placed in the closed position and the speed signal indicates that the rotational speed of the crankshaft exceeds a preset speed, and the control device being further configured to practice one of the remaining slow down controls when the speed signal still indicates that the rotational speed of the crankshaft exceeds the preset speed.