US 4,962,738 A · Ignition control system for an internal combustion engine

Abstract

An ignition control system for an internal combustion engine adapted to control ignition timing based on the internal pressure in an engine cylinder. In one embodiment, ignition timing is determined based mainly on the rotational position (i.e., crank angle) of a crankshaft sensed by a crank angle sensor at the time or normal operation of the crank angle sensor, whereas it is determined based on the internal pressure in the engine cylinder sensed by a cylinder internal pressure sensor at the time of failure in the crank angle sensor. In the latter case, the output of cylinder internal pressure sensor is differentiated and then compared with a reference signal of a predetermined level so that ignition is effected when the differentiator output crosses the reference signal level for the second time per engine cycle. In another embodiment, a target ignition timing is determined based on the internal pressure in the engine cylinder and the intake pressure in an intake pipe. When the internal pressure in the engine cylinder as sensed by a cylinder internal pressure sensor becomes equal to the target ignition timing, ignition is effected.

Claims7

Dependent claims

An ignition control system for an internal combustion engine having an engine cylinder and a crankshaft comprising:

rotational position sensing means for sensing the rotational position of the crankshaft and generating an output representative of the sensed crankshaft rotational position;
engine load sensing means for sensing an engine load and generating an output representative of the sensed engine load;
cylinder internal pressure sensing means for sensing the pressure in the engine cylinder and generating an output representative of the sensed cylinder internal pressure;
ignition timing determining means connected to receive the outputs of said rotational position sensing means and said engine load sensing means for determining appropriate ignition timing based on the sensed rotational position of the crankshaft and the sensed engine load at the time of normal operation of said rotational position sensing means, said ignition timing determining means being further connected to receive the output of said cylinder internal pressure sensing means for determining appropriate ignition timing based on the sensed cylinder internal pressure at the time of failure in said rotational position sensing means;
and
igniting means connected to receive the output of said ignition timing determining means for igniting the engine at the ignition timing which is determined by said ignition timing determining means.

3 more elements

An ignition control system for an internal combustion engine having an engine cylinder and a crankshaft comprising:

cylinder internal pressure sensing means for sensing the pressure in the engine cylinder and generating an output representative of the sensed engine cylinder pressure;
ignition timing determining means for determining an appropriate target ignition timing based on sensed operating conditions of the engine;
reference signal generating means for calculating a specific pressure in the engine cylinder which corresponds to the target ignition timing determined by said ignition timing determining means, and for generating a reference signal representative of said specific pressure in the engine cylinder;
ignition signal generating means connected to receive the outputs of said cylinder internal pressure sensing means and said reference signal generating means for generating an ignition signal at the time when the output of said cylinder internal pressure sensing means becomes equal to the output of said reference signal generating means;
and
igniting means connected to receive the output of said ignition signal generating means for igniting the engine when it receives an ignition signal from said ignition signal generating means.

3 more elements

Dependencies are inferred from the claim text.

Ignition control system for an internal combustion engine

Life of this patent

Ignition control system for an internal combustion engine

Life of this patent

Abstract

Claims7