A closed loop air-to-fuel ratio control system having an oxygen responsive sensor and a feedback circuit is disclosed. The sensor is disposed in an exhaust passage to produce a voltage indicative of the oxygen concentration in the exhaust gas. This voltage is integrated in the feedback circuit to cause the mixture air-to-fuel ratio to be corrected in response thereto. During specific engine conditions such as engine idling and low temperature of the exhaust gas, the integration is stopped to thereby switch off the closed loop to an open loop. The engine, on this occasion, can be supplied with the air-fuel mixture of an arbitrary ratio irrespective of the oxygen concentration in the exhaust gas, resulting in the optimum air-to-fuel control well-matched to the engine conditions.

Method and system for controlling the mixture air-to-fuel ratio

A fuel injection rate control system for a fuel-injection internal combustion engine, wherein basic fuel injection rate signals are produced upon detection of the load on the engine and the engine output speed and are modified by the correction values read out from a collection of data indicating various correction values in terms of the engine output speed and the engine load. When the correction values selected are zeros or smaller than a predetermined value, the fuel injection rate may be controlled to achieve a predetermined air/fuel ratio in the engine through detection of the air/fuel ratio of the mixture produced in the engine.

Load dependent fuel injection control system

This disclosure relates to a system for analyzing the performance of a reciprocating piston, internal combustion engine such as a diesel engine. Sensors are connected to the engine, which respond to various operating parameters, and signals representing the parameters are transmitted to computer processing equipment. A speed sensor responds to the movement of an engine part such as the teeth of the engine fly-wheel ring gear, and the processor calculates a function representing the change in the instantaneous engine kinetic energy. The kinetic energy change data are accumulated during an engine acceleration run and again during a deceleration run. The signals from an engine cycle event sensor are processed to indicate the firing intervals of the cylinders and thereby to correlate the engine acceleration and deceleration data. The changes in kinetic energy during the cylinder firing intervals are measured during engine acceleration, and the kinetic energy changes are again measured during deceleration, the two sets of measurements being at substantially the same engine speed. For each cylinder, the measurement on deceleration is subtracted from the related measurement on acceleration, to obtain the net work produced by each cylinder. A similar procedure may be followed to obtain the work done over segments of each firing interval, to thereby check the compression balance of the cylinders.

Diagnosis of engine power and compression balance

An electronic engine control apparatus includes a digital computer which receives sensor signals indicative of various engine operating parameters and calculates corresponding settings of actuators used to control the energy conversion process of an internal combustion engine. The apparatus has a memory for storing and holding data independently of an ignition switch being turned off. The apparatus includes a data input for inputting data specifying a function to be performed, a memory location and a numeral. The computer is programmed to perform the function using the numeral and the memory location. The function to be performed may include modifying data in the memory location in accordance with the numeral.

Electronic engine control system for controlling the energy conversion process of an internal combustion engine

In a closed loop electronic fuel injection control unit having a basic fuel schedule in response to engine operating conditions, the amount of oxygen in the exhaust gases is detected and compared with a desired value to provide an error signal. The error signal is shaped to form a series of binary pulses of alternating voltages of constant amplitude in correspondence with the plus and minus deviation from the reference voltage which represents the desired oxygen quantity. The binary pulses are amplified by a variable gain amplifier to provide a signal which is used to adjust the basic fuel schedule. The time duration of each binary pulse is measured by a counter to provide an output when a pulse width reaches a predetermined interval. The counter output is coupled to the amplifier to increase the amplifier gain to change the rate of fuel supply.

Closed loop electronic fuel injection control unit

A thermo reactor is formed as an after-burner to receive the exhaust gases and burn CO and unburned hydrocarbons; connected in series therewith, downstream, is a catalytic reactor to reduce nitrogen oxides. An oxygen sensor is exposed to the exhaust gas stream between the thermo reactor and the catalytic reactor and supplies a control signal to an amplifier which, in turn, controls one or both of the components air and fuel of the fuelair mixture to the engine in such relative proportions of mass that the exhaust sensed by the sensor is just slightly below the stoichiometric ratio of air and fuel ( lambda 1.0).

Exhaust gas composition control with after-burner for use with internal combustion engines

The air flow rate and the speed of an internal combustion engine are sensed and translated into pulse trains of variable frequency. During a time interval defined by the rpm related signal, a digital counter receives and counts the air flow rate frequency. Subsequently, the contents of this counter are counted out by a pulse train whose frequency is adjustable depending on other engine conditions such as start-up, warm-up, idling, full-load and the like. The apparatus also includes circuitry for generating a control pulse of minimun length.

Method and apparatus for generating fuel injection valve control pulses

Verfahren und vorrichtung zur bestimmung der dauer von einspritz-steuerbefehlen bei einer brennkraftmaschine

Verbindungskabel zum Anschluß von Komponenten an einen Rundfunkempfänger mit integrierter Fernsprecheinrichtung

The cable (80) has a plug contact arrangement (55) to connect the components at a corresponding plug site (40) of the radio receiver (1). The connection cable (80) has several preferably multiple terminal connection lines (76,78) for connecting the components (15,20). At least one connection line (78) has a further plug site (70) on its end remote from the plug contact arrangement, for connecting a further connection cable (82). The data can be exchanged between the components and a control circuit (10), integrated in the radio receiver (1), over at least one of the connection lines. The data exchange serves to detect the components in the control circuit (10) and to control the components through the control circuit (10).

Bernd Peter

Papers

Exhaust gas composition control with after-burner for use with internal combustion engines

Method and apparatus for generating fuel injection valve control pulses

Verfahren und vorrichtung zur bestimmung der dauer von einspritz-steuerbefehlen bei einer brennkraftmaschine

Verbindungskabel zum Anschluß von Komponenten an einen Rundfunkempfänger mit integrierter Fernsprecheinrichtung

Cable for connecting external units to a combined broadcast receiver and telephone