Abstract: An electromagnetically-actuated fuel injector of the type having a spring-biased flat armature and a ball valve element is provided with an improved arrangement for preventing wobble or flutter of the armature, particularly during operation. The armature and ball valve are urged to the closed position by a helical coil spring coaxially aligned with and acting in compression against the armature. The end of the spring in engagement with the armature is modified or formed such that it includes a portion which is inclined axially from a plane normal to the axis of the armature so as to concentrate most of the axial spring force at the location where it engages the armature. As that location is to one side of the axis of the armature, the remote, or opposite, edge of the armature forms a pivot with a stationary part of the injector and reduces or eliminates armature wobble.

Abstract: Information relating to relative fuel pump camshaft advance angle is compared with a SOC signal indicative of the start of combustion in a reference cylinder to generate an adaptive trim table which is used, in a first control scheme to calculate an actual combustion angle for closed loop control over combustion timing only in the event of a loss of the SOC signal. In an alternate control scheme, the values from the adaptive trim table are always used to calculate the actual combustion angle for closed loop control.

Abstract: An electromagnetically-actuated fuel injector of the type having a spring-biased flat armature and a ball valve element is provided with an improved arrangement for preventing wobble or flutter of the armature, particularly during operation. The substantially-circular armature includes a portion contoured to define a pivot axis for the armature as it engages a stationary part of the injector. This pivot axis is conveniently provided by a chordal edge on the armature. This arrangement aids in reducing wobble by the armature and is further enhanced by concentrating the spring force on the armature remote from the pivot axis. This concentrated spring force is obtained by providing a spring seat on the armature which is inclined such that the spring experiences greater compression where the spring force is required.

Abstract: According to the invention, the time for start of combustion in an engine cylinder is provided by disposing a sensor in the combustion chamber of the cylinder, said sensor providing a signal indicative of the amplitude/time of the combustion event within the cylinder. Two signal levels are measured, a first level which is above the noise in the signal and a second level which is below the maximum amplitude of the signal which may be attenuated by carbon buildup on the sensor. By extrapolating backwards from these two sensed levels, a reference time for start of combustion is calculated.

Abstract: A method and apparatus are provided for controlling the torque or fuel quantity limit to an internal combustion engine such as a diesel engine, at least partly as a function of the sensed level of smoke in the exhaust gas stream of the engine. An open-loop preliminary fuel quantity limit signal is provided as a function of engine speed. The actual smoke level is compared with a smoke limit value for the particular operating condition, and an error signal indicates the sense and possibly the magnitude of any difference. The error signal is the basis of a compensating signal which is added to the open-loop preliminary fuel quantity limit signal such that the resulting fuel quantity limit signal provides for maximum torque without exceeding the smoke limit. The smoke level is obtained by a direct measurement of the particulate level or the like in the exhaust gas stream. An alarm may be provided for indicating when the actual smoke level exceeds some threshold relative to the smoke limit.

Abstract: A normally-open, solenoid-controlled valve rapidly controls the flow of liquid between a high pressure supply and a relatively lower pressure drain. The valve includes a stationary valve-seat spindle and a cylindrical valve sleeve encircling and slidable along part of the valve-seat spindle. The valve-seat spindle is provided with an annular control edge and the valve sleeve includes a frustoconical pressure-responsive contact surface which is moved into and out of valve-closing contact with the control edge by means of axial reciprocation of the valve sleeve between valve-closed and valve-open positions. The valve-seat spindle includes a flow passage therein which is in continuous fluid communication with a high pressure fluid inlet in a valve housing and which extends to and discharges into a plenum region formed between the spindle and the sleeve adjacent to the control edge and relatively toward that part of the seat spindle along which the valve sleeve slides.

Abstract: A normally-open, solenoid-controlled valve includes a stationary valve-seat spindle and a cylindrical valve sleeve encircling and slideable along part of the valve-seat spindle. The valve-seat spindle has an annular control edge and the valve sleeve includes a pressure-responsive surface which is reciprocably moved into and out of valve-closing contact with the control edge. The valve-seat spindle includes a flow passage therein extending to and discharging into a plenum region formed radially inward of the control edge between the spindle and the sleeve. The pressure-responsive surface of the valve sleeve is a substantially continuous frustrum of a cone whose apex extends in the direction of the valve opening and which extends radially outward from a sleeve inner diameter A to an outer diameter C (point C) of discontinuity in that surface.

Abstract: A method and apparatus for controlling the recirculation of exhaust gas in a diesel engine includes an EGR valve responsive to an EGR control signal for relatively opening and closing a recirculation duct to the passage of exhaust gas therethrough. A sensor provides a signal indicative of the level of particulates in the exhaust gas stream. Control circuitry responsive to various signals indicative of engine operating conditions, including the signal indicative of exhaust gas particulate level, provides an EGR control signal for regulating the EGR valve at least partly as a function of the sensed level of particulates in the exhaust gas stream. The engine operating condition signals typically are indicative of the speed of the engine or fuel injection pump, the engine load, and engine operating temperature.