摘要:
A circuit arrangement for obtaining an interference-free trigger signal such as for a fuel apportionment device from the ignition signal of an internal combustion engine, particularly one having a current-regulated final ignition stage. The output of the circuit arrangement begins when a signal derived from the final ignition stage exceeds a first, high threshold value and is terminated when, after falling below a second, low threshold value, a predetermined time lag period has ended. In this manner, a desired interference-free trigger signal is obtained which can be used to trigger various rpm-dependent circuit arrangements, such as electronic fuel apportionment and gear control.
摘要:
A fuel injection system of an internal combustion engine generates valve-actuating pulses for actuating electromagnetic fuel injection valves. The length, or duration, of these valve actuating pulses is a function of various engine conditions and they are generated by a pulse-length multiplying circuit from preliminary control pulses derived from two basic engine variables, e.g. engine speed and air flow rate. In order to compensate for the decreasing pressure drop across the injection valve orifice at high engine load due to increasing manifold pressure, the invention describes methods for lengthening the fuel valve-actuating pulses by engaging the pulse-length multiplying circuit, in order to change the charging or discharging times of the timing capacitor therein. Another method proposed is to engage the battery-voltage compensation circuit in the system to lengthen the valve-actuating pulses. Electronic circuitry to perform these corrections is also described.
摘要:
The cyclic control pulses for actuating the fuel injection valves of an internal combustion engine are extended during engine starting at low temperatures. The degree of pulse extension, i.e. of fuel enrichment, is made dependent on engine temperature and decreases as a function of cranking time. In addition, a repeated starting attempt will be accompanied by reduced pulse extension to prevent excessive enrichment of the mixture. The pulse extension may also be retained for a period of time after engine cranking to insure smooth running.
摘要:
To provide an undistorted square wave output signal under control of a switch subject to contact chatter so that the square wave will accurately reflect the operating instant of the switch, as commanded, regardless of contact chatter, a timing circuit is provided having a timing capacitor and a charge and discharge circuit therefor, connected to a threshold circuit, the threshold circuit response level and the charge circuit of the timing capacitor being dimensioned to cause the capacitor to charge to a level such that the threshold circuit responds only when the switch has changed state, typically closed after interrupting an inductive load, such as the primary of a spark plug, for a predetermined time period as determined by the switch contact chatter characteristics of the switch itself, for example about 0.6 to 1 millisecond in the case of automotive ignition breaker switches; a feedback connection is provided between the threshold circuit and the input stage to the circuit to disable transfer of a signal representative of change of the switch through the circuit unless the threshold level of the threshold circuit has been exceeded so that the threshold circuit could respond.
摘要:
To prevent bucking of a fuel injection operated automotive engine, under transient dynamic conditions, due to resilient suspension thereof, a timing capacitor in the fuel injection system has an auxiliary capacitor connected in parallel thereto over a diode, the auxiliary capacitor having its own charge circuit, and the diode and charge circuit being so arranged that the diode becomes conductive when the voltage across the main capacitor exceeds the voltage across the auxiliary capacitor, thus delaying and flattening the charge rate to the main capacitor without, however, detracting from total charge being placed on both capacitors to prevent excessive changes in fuel valve injection timing under transient engine operating conditions.
摘要:
An electrically controlled fuel metering system having an air flow rate meter device in the air intake tube and a subsequent linearizing circuit layout is proposed. The linearizing circuit layout functions in accordance with the point-slope method and is embodied as a voltage-to-current converter. A first exemplary embodiment of the linearizing circuit layout has transistors coupled with one another respectively at the base and collector sides, the emitters of which are connected with different potentials and are triggered on the base side. In a second exemplary embodiment, individual transistors or transistors which are combined into groups receive their trigger signal via separate amplifiers, while the collectors in turn are carried to a common output point and the emitters likewise have different signal levels. Because of its relatively simple design, the proposed embodiments are particularly well suited to the purposes of integration.
摘要:
A fuel injection control system generates control pulses which open the fuel injection valves of the engine. The pulse duration is proportional to the injected fuel quantity and can be altered in dependence on air temperature by a circuit which includes a temperature-sensitive resistor. The voltage at this resistor controls a transistor which supplies a supplementary charging current for a timing capacitor.
摘要:
A fuel injection control circuit includes a monostable multivibrator for generating injection valve control pulses. The circuit includes a trigger sub-circuit which controls the switching characteristics of the monostable multivibrator in a well-defined manner which is immune to electrical noise and to voltage fluctuation in the supply lines of the vehicle.
摘要:
A fuel mixture control apparatus for an electronic fuel injection system for internal combustion engines. In a warm-up controller, the fuel injection control pulses are lengthened for enrichment of the fuel-air mixture during engine warm-up on the basis of signals supplied by a temperature transducer. In order to make the warm-up enrichment dependent on prevailing engine states, for example on the conditions of idling and partial or full load, circuitry is provided to sense these conditions and to suitably alter the enrichment factor. A further circuit suppresses the dependence or enrichment on engine status during engine starting. Various embodiments are presented.
摘要:
A device is proposed for regulating the fuel-air ratio in the operating mixture of an internal combustion engine and for monitoring the operational readiness of a .lambda. sensor controlling the regulating device and functioning by the principle of ion conduction in solid electrolytes. The .lambda. sensor has an adjustable, constant reference voltage switched opposite to it. The reference voltage approximately equals the average sensor output voltage. The level of the resultant voltage, which is established with the aid of the resultant current and has values located symmetrically with respect to the reference voltage, is monitored by comparator devices. The output signal of the comparator devices is logically processed and furnishes a signal as to the operational readiness of the sensor. In order to generate the reference voltage, a voltage divider branch having high resistance is disposed parallel to a voltage divider branch of relatively low resistance; the latter voltage divider branch further serves to establish the threshold values of the comparator devices. Because it is independent of the current draw of the comparator devices, the desired reference voltage can be adhered to very precisely, and thus the desired regulating point at which closed-loop control or regulation begins of the regulating device can also be adhered to very precisely.