The Bendix Corporation

Other

Ex-cell-o Gmbh

Alvin D Toelle

Gene Y Wen

Melvin A Rode

Thomas W Hartford

Jack R Phipps

John D Camp

John J Schira

Allan Lee Oberstadt

For application in controlling fuel flow to a gas turbine engine, the control valve includes one or more fuel inlet manifolds, a fuel outlet manifold and a fuel drain manifold in fuel flow relation with a longitudinal bore in a valve sleeve. A hollow spool valve is slidably disposed in the sleeve bore and includes a metering valve thereon movable past a fuel inlet aperture to meter fuel flow from the fuel inlet manifold to the fuel outlet manifold. The spool valve also includes a shut-off valve thereon for terminating fuel flow to the fuel outlet manifold under certain conditions. The hollow spool valve includes a longitudinal bore in fuel flow relation with the fuel outlet manifold and fuel drain manifold and a drain valve in the spool bore openable when fuel flow to the fuel outlet manifold is interrupted by the shut-off valve so that fuel can drain from the fuel outlet manifold to the drain manifold and closeable during metered fuel flow to the fluid outlet manifold. The drain valve preferably includes a drain valve assembly in the spool bore movable with the spool valve and an unseating member in the spool bore in fixed position engageable with the valve member of the drain valve assembly to unseat same when the shut-off valve is closed by sliding movement of the spool valve.

Fluid control valve

An ignition advance timing system for generating the ignition signal or the injection signal in an engine utilizes both the advantages of an angular-based system and a time-based system. A tooth wheel (10) operatively connected to the crankshaft of the engine (26) having groups (14) of teeth (16, 22, 24) positioned thereon. Each group represents the angular range of ignition or injection for a particular cylinder. The angular space (29) between each group of teeth allows a microprocessor (12) to begin a computing period (36) free of any interrupt signals generated by the teeth in the wheel. The microprocessor determines the desired angle which is synchronized with the teeth in the wheel to find the closest advance angle and by means of a timer the desired angle is generated.

Ignition advance timing system

An apparatus and method for supplying a predetermined volume of liquid fuel (20) to a cylinder of a diesel engine (10) is provided. A storage tank (22) stores a column of the liquid fuel (20) in a storage area (24). A position sensor (36) transmits an analog signal proportional to the height of the fuel (20) in the tank (22). A pressure transducer (32) disposed at the bottom of the storage area (24) transmits an analog signal corresponding to the static fluid pressure at the bottom of the storage area (24). A temperature transducer (56) disposed along a fuel rail (16) transmits an analog temperature signal to an electronic fuel injection computer (14). The computer (14) converts the analog height signal, the analog temperature signal and the analog pressure signal into digital values and mathematically divides the resulting digital values of height and pressure to obtain a digital value for the fuel density. A programmed ROM (72) of the computer (14) produces an output binary signal representative of a predetermined viscosity based on the instantaneous values of the temperature and the density of the fuel (20) over a range of values of the density and the temperature. The ROM (72) generates a three-dimensional surface representing values of viscosity based upon the temperature and the density. The output binary signal of the ROM (72) is used by the computer (14) through a diesel output control (11) to control a metering solenoid (13) of a fuel injector (12) which injects fuel into a cylinder of the engine (10).

Viscosity compensated fuel injection system

A closed loop fuel management system is disclosed in which an improved dual integral controller provides both transient and gross correction for an electronic fuel injection system operating at a predetermined air/fuel ratio. The controller has cascaded dual integrators including a primary integrator with a relatively fast integration rate utilized for transient control and a secondary integrator with a relatively slow integration rate utilized for gross control such as ageing effects and altitude compensation. The controller responds to several engine operating conditions and to rich fuel power demands to switch from closed loop to open loop control while maintaining the gross system correction provided by the operating point of the secondary integrator.

Open loop compensation circuit

A closed loop exhaust gas recirculation system for an internal combustion engine having an intake system, an exhaust manifold, a throttle disposed within the intake system for controlling air flow therein, a conduit coupling the exhaust manifold to the intake system for supplying exhaust gases back to the intake system for controlling the generation and emission of oxides of nitrogen and for improving driveability. The system includes a first memory pre-programmed with a look-up table of optimal values of absolute manifold pressure (MAP.sub.0) as a function of engine speed (RPM) and throttle position (.theta.). The actual operating parameters of absolute manifold pressure (MAP), engine speed (RPM) and throttle position (.theta.), or alternatively air flow (AF), are accurately sensed. The actual values of throttle position or air flow and RPM are used to address the first memory which outputs the pre-programmed optimal value of MAP. The actual value of throttle angle or air flow may be compensated for ambient barometric pressure and/or altitude, if desired. The actual value of MAP is compared with the optimal value of MAP.sub.0. The output of the comparator is used to close the loop and control the position of a valve positioned at least partially within the conduit such that the amount of recirculated exhaust gas (EGR) supplied to the input system is increased if MAP&lt;MAP.sub.0 and the amount of EGR is decreased if MAP&gt;MAP.sub.0.

Closed loop exhaust gas recirculation system

A dual mode control system for operating an electronic fuel injection system for an internal combustion engine so as to achieve an optimal compromise between engine emissions, fuel economy and driveability. A closed loop control circuit is provided which senses the amount of oxygen in the engine exhaust and normally drives an integrator in a closed loop mode of operation to operate the electronic fuel injection system at the stoichiometric air/fuel ratio at which the best conversion efficiency of hydrocarbons, carbon monoxide and nitrous oxides occur. An open loop control circuit senses high speed operation where hydrocarbons and carbon monoxide conversion are normally high and where nitrous oxide emission is not critical and clamps the output of the integrator to a predetermined value which operates the electronic fuel injection system at a nonstoichiometric, relatively lean, air/fuel ratio for improved fuel economy. Further open loop control circuitry may be provided to sense very low speed, low engine load operation where nitrous oxide emission is negligible for similarly switching to an open loop mode of operation with the integrator output clamped. An override circuit may be provided which senses engine acceleration which normally requires a relatively rich air/fuel ratio for good driveability and overrides the clamped integrator output to restore the closed loop mode of operation regardless of the engine speed thereby achieving an optimal compromise between engine emissions, fuel economy and drivability.

Dual mode hybrid control for electronic fuel injection system

A closed loop programmable EGR control system is disclosed. The EGR control system comprises a first read only memory having a look up table of base EGR pulse widths as a function of engine speed and absolute manifold pressure. This base EGR pulse width is corrected to a total desired pulse width by adding a correction pulse width obtained from a second read only memory. The second ROM stores values of the correction pulse width in a look up table as a function of engine speed and engine coolant temperature. This desired value of EGR pulse width is then compared to the actual EGR flow as sensed directly by a differential pressure transducer located in the exhaust gas recirculation conduit and an error signal is generated therefrom. The error signal is subsequently used to operate a solenoid pilot valve that alternately applies either a vacuum or atmospheric vent at a controllable rate to an EGR valve regulating the amount of exhaust gas recirculated to thereby reduce the error between the actual and desired EGR values.

Closed loop programmable EGR with coolant temperature sensitivity

A closed loop exhaust gas recirculation (EGR) control system for an internal combustion engine having an intake system, an exhaust system, a throttle disposed within the intake system for controlling air flow therein, a conduit coupling the exhaust system to the intake system for supplying exhaust gas back to the intake system for controlling the generation and emission of oxides of nitrogen and for improving drivability and avoiding engine roughness. The EGR control system of the present invention includes a first memory pre-programmed with a look-up table of optimal EGR values indicative of EGR valve position or the like determined as a function of engine speed and throttle position and a second memory pre-programmed with the look-up table of optimal EGR values determined as a function of engine speed and absolute manifold pressure. The actual operating parameters of engine speed, throttle position and absolute manifold pressure are accurately sensed and stored as multi-bit binary numbers or words indicative thereof. The most significant bits (MSB) of the words are used to address the first and second memory while the least significant bits (LSB) of the words are used to perform a double linear interpolation of the accessed values to compute accurate first and second EGR values. The second EGR value is substracted from the first EGR value to determine a difference indicative of the current EGR valve error. A previously computed and stored EGR error value used to determine the last valve position adjustment is then substracted from the current EGR error value to determine the total change in error value required to correct the EGR valve position at the next adjustment. A fractional portion of the total change in EGR error value is then applied to the previously stored EGR error value to update same so as to avoid rapid or abrupt adjustments in the valve position so as to avoid engine roughness etc. The updated EGR error value is converted into a control signal which is used to adjust the position of the EGR valve at the next scheduled valve adjustment time so as to regulate EGR flow as desired.

Closed loop exhaust gas recirculation control system

In a closed loop fuel injection system for an internal combustion engine, a control system responding to several engine operating conditions and to rich fuel power demands operates to normalize the air/fuel ratio to a fixed air/fuel ratio. In the preferred embodiment the system responds to the operating temperature of a gas sensor to effectively remove the influence of the sensor control signals at nonoperational temperature upon the air/fuel ratio developed by the electronic control unit. In addition transducers responding to engine speed, wide open throttle, and coolant temperatures generate control signals to the control system indicating a requirement for engine operation of normalized air/fuel ratio.

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Fenton, MI, United States of America

Alvin D Toelle