Alliedsignal Inc.

Precision Engine Controls Corporation

Stephen H Nussbaum

Jeffrey E Folts

Bradford A Lessard

Apparatus, and a corresponding method for its operation, for controlling the air/fuel ratio in a large engine having one or more banks of cylinders with separate intake and exhaust manifolds. Oxygen sensors in the manifolds are sampled periodically to provide the apparatus with an indication of the level of oxygen, and therefore an indication of the level of various pollutants, in exhaust gases discharged from the engine. The apparatus, preferably in microprocessor form, computes a fuel control correction based on the difference between the sensed oxygen level and a desired oxygen level in each exhaust manifold. The correction is applied in the form of a change to the pulse width of a binary control signal applied to a solenoid valve. In the illustrative embodiment, the solenoid valve is coupled to a fuel pressure regulator and functions to vent an air chamber in the regulator when the solenoid is actuated. Changing the pulse width of the control signal varies the average fuel pressure and thereby controls the air/fuel ratio, which in turn corrects the oxygen level in the exhaust manifold. The controller also monitors various temperatures in the engine and selectively disables control of the air/fuel ratio when selected temperatures fall outside assigned limits.

Air/fuel ratio controller for larger internal combustion engines

A method of and apparatus for enabling at least one spark plug of a internal combustion engine to provide a fuel igniting spark at a selectable time in the engine cycle is disclosed. Sensors provide a first engine rotation determined pulse train the repetition rate of which is the same as the number of revolutions per second of the engine and a second engine rotation determined pulse train the repetition rate of which is an integral multiple of that of the first pulse train. The reference pulse initiates a count of pulses in the second pulse train and, upon reaching a preselected count, initiates a count of pulses in a third independent pulse train having a much greater repetition rate. The spark plug is enabled when the third pulse train count reaches a preselected count. In the event the engine is a multi-cylinder engine having at least one spark plug for each cylinder, the pulses in the second pulse train are counted up to different preselected counts for different cylinders and a different spark plug is enabled for each different preselected count.

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Temecula, CA, United States of America

Stephen H Nussbaum