C.a.v. Limited

Lucas Industries Limited

The Lucas Electrical Company Limited

Malcolm Williams

Christopher Robin Jones

John P Southgate

Richard G Woodhouse

Anthony John Adey

Richard William Crookes

Albert R Tingey

Steven J Russell

Geoffrey Albert Brunt

Adrian Walter Melady

Geoffrey Richard French

Gordon Harris Leonard

Nicholas John Bard

An i.c. engine fuel control includes a main fuel control which controls fuel flow to the engine in accordance with one or more engine operating parameters. A roughness sensor provides an electrical signal varying with the magnitude of fluctuations in the engine speed and an integrator integrates the error between this signal and a reference signal. Two active clamp circuits operate to limit the excursion of the integrator output which provides a limited authority trim input to the fuel control.

Fuel control system for an internal combustion engine

An electronic fuel injection control includes a main fuel control circuit, a transient enrichment control circuit temporarily increasing fuel flow as a result of increasing of a demand signal, and temperature compensation means non-linearly varying the effect of the enrichment control with engine temperature. The temperature compensation means preferably includes a temperature 'window' detector which acts to increase the effect of the enrichment control whenever the engine temperature is between prescribed limits.

Internal combustion engine

An i.c. engine fuel control system includes a closed loop roughness control, utilizing a roughness sensor circuit, an integrator which integrates the error between the roughness signal and a reference signal and modifies the fuel flow to the engine via a main fuel control with a variable frequency clock. During acceleration and deceleration the closed loop is interrupted by means of a circuit including two differentiators which are sensitive to throttle opening (speed demand) and actual speed respectively, and switches controlled by these differentiators.

An i.e. engine fuel control system includes a main fuel control which controls fuel flow to the engine in accordance with one or more engine operating parameters. The operation of the fuel control can be modified by a roughness sensing circuit which produces a roughness signal output dependent on the magnitude of fluctuations of engine speed. This output is applied to an integrator which provides a limited authority trim signal to the fuel control in accordance with the time integral of the error between the roughness signal and a speed-dependent reference signal generated by a speed-shaping circuit.

A solenoid drive circuit includes two output transistors in parallel paths of relatively high and low resistance respectively. The low resistance path transistor is controlled by a voltage comparator arranged to compare the voltage across a common current sensing resistor with a reference voltage. When the input to the circuit is low, the high resistance path transistor is biased on, but where the current is below a set level, only the low resistance path transistor conducts. Only when the comparator changes state as the solenoid current exceeds its set level does switching off of the low resistance path transistor permit the other transistor to turn on. A delay circuit is included which operates to prevent the low resistance path transistor turning on if there is a short circuit across the solenoid.

Solenoid drive circuits

An electronic fuel injection control includes a main fuel control circuit which operates to control fuel flow to the engine by controlling the duration of engine-synchronized fuel valve opening pulses in accordance with at least one engine parameter. An auxiliary pulse source is arranged to provide extra unsynchronized pulses to improve the acceleration characteristics of the control, such pulses being produced when the throttle is opened. A muting circuit is provided which operates for a fixed period following closing movement of the throttle, to prevent the auxiliary pulse source responding to throttle opening during said period. The muting circuit prevents excess fuelling during gear changes etc.

Fuel injection systems

An electronic fuel injection control includes a main control circuit which controls fuel flow to the engine by controlling the duration of pulses applied to fuel valves. In addition there is a transient fuel varying control including a differentiating circuit which differentiates the signal from a throttle position transducer. This differentiator controls a variable frequency clock which forms part of the main fuel control so that the pulse duration is lengthened or shortened for a given value of the engine parameter which controls the main fuel control according to the rate of increase or decrease of the throttle position signal.

Electronic fuel injection control for an internal combustion engine

A fuel injection system for a V- or flat-type internal combustion engine with split intake/exhaust systems, includes injectors respectively associated with the intake systems and a pair of transducers associated with either the intake systems or the exhaust systems. A control unit alternately energizes the injectors in known manner and the outputs from the control unit to the injectors are used to operate a multiplex circuit whereby the transducers are alternately connected to the control unit, to control the pulse length of the output pulses therefrom.

Fuel injection system for an internal combustion engine

A fuel injection system for a compression ignition engine includes pulse length control means which determines the instant and duration of opening of a series of injector valves in accordance with the output of a digital memory unit, empirically programmed to match the specific engine. The memory is addressed by two inputs, one derived from an engine speed transducer and the other derived by combining analogue signals from the speed transducer and from a demand transducer. The system operates without any feedback representing the quantity of fuel injected so that no fuel flow transducers are required.

Fuel injection systems for compression ignition engines

In an engine control system, particularly for fuel injection, the frequency of a variable frequency clock is compared with an output signal from a memory device and the difference used to control an engine function. The frequency of the clock is determined by the collector current of the transistor having two variable resistors controlling its emitter and base currents respectively. This invention relates to engine control systems and is particularly, but not exclusively, intended for use in fuel injection systems for engines.

Engine control system

An engine exhaust recirculating valve is operated by a solenoid. The valve is normally open, but has an electronic control circuit, including an engine speed transducer, which energizes the solenoid to close the valve when the engine speed is above a predetermined level.

Pollution control arrangements for engines

A process control apparatus, for example for internal combustion engine fuel injection control, includes a digital memory which produces an n-bit digital output in accordance with two independently variable input signals. The m most significant bits are transferred to a counter which is clocked to give a pulse length output. The n-m least significant bits control a logic circuit which is used to program another counter which is used to introduce an added delay to each output pulse. This arrangement enables higher resolution to be obtained using a limited size main counter.

Process control apparatus

A fuel supply system for an internal combustion engine includes a pump having a control member movable by an actuator. The actuator is powered by an amplifier which receives a control signal from an operational amplifier. One input of the opertional amplifier is connected to a summing junction to which signals representing speed demand, actual speed and control rod position are supplied by three transducers. The signal from the transducer which indicates the control rod position passes by way a circuit means which ensures that a derivative of the signal is applied to the summing junction.

Fuel systems for internal combustion engines

A Fuel System for an engine includes an actuator for controlling the output of a pump and a pair of d.c. supply lines the voltage across which is determined by a voltage regulator. A series circuit including a resistor, a relay coil and a transistor is connected across the supply lines and first means is provided for turning transistor off if the current flow through the actuator exceeds a predetermined value. Second means including a resistor is provided to maintain transistor de-energised when it has been turned off to prevent further operation of the actuator. In addition switch means is provided to short circuit the resistor if the potential between the supply lines falls below a second predetermined value.

Fuel supply systems for diesel engines

A fuel system for an engine has a first summing amplifier to which are fed signals representing demanded and actual values of the output of a pump supplying fuel to the engine, together with a signal representing engine speed. The summing amplifier compares the signals it receives and produces an output controlling the output of the pump, and there is also a second summing amplifier to which are fed electrical signals representing engine speed and a reference, a discriminator coupling the two summing amplifiers to a means for controlling the pump, so that the output from the discriminator at any instant is the output from the amplifier demanding the least fuel.

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Solihull, United Kingdom

Malcolm Williams