Method and means for reducing exhaust smoke in i.c.engines

Claim 2

Means for reducing exhaust smoke emission from an internalcombustion engine having a fuel control by which the quantity of fuel delivered to the engine for combustion is controlled, which means comprises a device for measuring the density of smoke in the gaseous exhaust discharged from the exhaust duct of the engine, the said device providing an output signal dependent upon the exhaust smoke density, said dEvice including an electrode supported by an electrically-insulating mounting adapted to locate the electrode in the path of the exhaust gases delivered through the exhaust duct, and an electrical measuring circuit to whose input the electrode is connected and which produces an electrical output signal corresponding to the electrical potential developed on the electrode by the impaction therewith of charged carbon particles in the exhaust gas, and control means responsive to the said output signal and arranged to adjust the fuel control automatically in response to the output signal in such a way as to adjust the fuel delivery in inverse dependence upon the measurement of exhaust smoke density.

Claim 3

Apparatus as claimed in claim 1 in which the control means responsive to the output signal comprises an electrohydraulic control circuit having a hydraulically-actuated output member coupled to the fuel control.

Claim 4

An internal combustion engine having a movable fuel control member, and having an exhaust duct and an electrode supported by an electrically-insulating mounting in the path of exhaust gas delivered through the said exhaust gas duct, as electrical measuring circuit to whose input the electrode is connected and which produces an electrical output signal corresponding to the electrical potential developed on the electrode by the impaction therewith of charged carbon particles in the exhaust gas, said output signal constituting a measurement of smoke density in the said exhaust gas, and control means responsive to the said output signal and operatively associated with the fuel control member, said control means automatically adjusting the travel of the fuel control member in the direction of increased delivery and thereby regulating the maximum fuel delivery in inverse dependence on the said measurement of smoke density.

Claim 5

An internal combustion engine having a movable fuel control member, and having an exhaust duct and an electrode supported by an electrically-insulating mounting in the path of exhaust gas delivered through the said exhaust gas duct, as electrical measuring circuit to whose input the electrode is connected and which produces an electrical output signal corresponding to the electrical potential developed on the electrode by the impaction therewith of charged carbon particles in the exhaust gas, said output signal constituting a measurement of smoke density in the said exhaust gas, and control means responsive to the said output signal and operatively associated with the fuel control member, said control means automatically adjusting the travel of the fuel control member in the direction of increased delivery and thereby regulating the maximum fuel delivery in inverse dependence on the said measurement of smoke density.

Claim 6

An internal combustion engine of the liquid-fuel-injection type having a fuel injection pump with a movable fuel delivery control member, and having an exhaust duct, and an electrode supported by an electrically-insulating mounting in the path of exhaust gas delivered through the said exhaust gas duct, an electrical measuring circuit to whose input the electrode is connected and which produces an electrical output signal corresponding to the electrical potential developed on the electrode by the impaction therewith of charged carbon particles in the exhaust gas, said output signal constituting a measurement of smoke density in the said exhaust gas, and control means responsive to the said output signal and operatively associated with the fuel control delivery member, said control means including an electrohydraulic control valve responsive to the output signal of the measuring circuit, and a hydraulic actuator controlled by said valve, the hydraulic actuator being mounted adjacent to the fuel injection pump so that its movable member constitutes a movable stop which limits the travel of the fuel control member in the direction of increased delivery in an adjustable manner, and thereby regulates the maximum fuel delivery in inverse dependence upon said measurement of smoke density.

Claim 7

An internal combustion engine of the liquid-fuel-injection type having a fuel injection pump with a movable fuel delivery control member, and having an exhaust duct, and an electrode supported by an electrically-insulating mounting in the path of exhaust gas delivered through the said exhaust gas duct, an electrical measuring circuit to whose input the electrode is connected and which produces an electrical output signal corresponding to the electrical potential developed on the electrode by the impaction therewith of charged carbon particles in the exhaust gas, said output signal constituting a measurement of smoke density in the said exhaust gas, and control means responsive to the said output signal and operatively associated with the fuel control delivery member, said control means including an electrohydraulic control valve responsive to the output signal of the measuring circuit, and a hydraulic actuator controlled by said valve, the hydraulic actuator being mounted adjacent to the fuel injection pump so that its movable member constitutes a movable stop which limits the travel of the fuel control member in the direction of increased delivery in an adjustable manner, and thereby regulates the maximum fuel delivery in inverse dependence upon said measurement of smoke density.

Claim 10

A method as claimed in claim 5 in which the said control signal supplied to the input of an electrohydraulic control circuit whose output is oPeratively associated with a fuel control of the engine.

Claim 11

A method as claimed in claim 6 in which the engine is of the liquid-fuel-injection type having a fuel injection pump with a movable delivery control member, and in which the electrohydraulic control circuit includes as its output member a hydraulic actuator whose movable member is utilised as an adjustable stop to limit the travel of the delivery control member in the direction of increased fuel delivery.