Abstract: A system for controlling the air-fuel ratio in an internal combustion engine provided with a fuel injector. The system has an O.sub.2 sensor for issuing signals on two levels, one corresponding to a high air-fuel ratio, the other to a low air-fuel ratio, and a feedback control device responsive to the signal from the sensor. The feedback control calculates a correction factor for maintaining the air-fuel ratio to a desired value during steady operation and for indicating the deviation in the ratio from the desired value during transient conditions. This deviation is employed to generate a transient correction value which is selected to minimize the deviation during transient conditions.

Abstract: Air-fuel ratio control of an internal combustion engine is performed using sensors for detecting operating conditions of the engine, such as the intake air amount, engine rotational speed, or air-fuel ratio; a fuel injection valve driven by an electrical signal to inject fuel; and a control circuit for receiving signals from the operating condition sensors, performing predetermined operations and generating an electrical signal for driving the fuel injection valve. The control circuit performs a step of calculating an air-fuel ratio variation D(A/F) with respect to an optimum air-fuel ratio based on the ratio of a change .DELTA.F, of an air-fuel ratio correction signal F during acceleration under air-fuel ratio feedback control based on a signal from the air-fuel ratio sensor, to an acceleration amount A, and a step of controlling a transient fuel correction ratio f(AEW) based on the obtained air-fuel ratio variation D(A/F).

Abstract: In an internal combustion engine, a base fuel amount is calculated, and an air-fuel ratio deviation for each region is determined by a predetermined engine operating parameter when the engine is in a transient state such as an acceleration state or a deceleration state. A transient fuel correction amount is calculated in accordance with the calculated air-fuel ratio deviation for each region determined by the predetermined engine operating parameter. A fuel amount to be supplied to the engine is calculated by correcting said base fuel amount in accordance with the transient fuel correction amount.

Abstract: In an internal combustion engine having a plurality of cylinders, an air-fuel ratio signal is sampled and held for a selected cylinder, and an air-fuel ratio feedback amount is calculated in accordance with the sampled and held air-fuel ratio signal. During a learning control, a cylinder on the leanest side is determined by changing the selected cylinder. During a feedback control without the learning control, the selected cylinder is fixed as the cylinder on the leanest side.

Abstract: A method for controlling the air-fuel ratio in an internal combustion engine in which the correction value of a transient fuel injection amount is decided, at a predetermined interval, in accordance with the acceleration or deceleration state of the engine, and the amount of fuel injection supplied to the engine is corrected by the decided correction value. In the process of the correction, the deviation of the air-fuel ratio from a reference air-fuel ratio in acceleration or deceleration of the engine is detected, and the correction value of the fuel injection amount correction in the transient state of the engine in accordance with the detected air-fuel ratio deviation is determined. In the correction of amount of fuel injection in the transient state of the engine, the correction value is decided on the basis of a factor for deciding the correction value and the blunted value of the factor for deciding the correction value.

Abstract: In a method for controlling an internal combustion engine, a control signal is calculated according to a signal output from a rotational angle sensor in accordance with intervals of a predetermined crank angle .theta..sub.o within a range from a reference position to a position which does not exceed a retard angle .theta. and the deviation from the retard angle .theta. does not exceed the crank angle .theta..sub.o. An angle deviation .theta..sub.s obtained as a remainder of a dividing operation is converted into a corresponding time period in accordance with a current average rotational speed of the engine. The time is counted in accordance with clock signals having a predetermined period. An internal combustion engine control signal is produced in accordance with this time counting operation. At least two instantaneous rotational speed data obtained for each angular signal from a rotational angle sensor are stored. The angle deviation .theta..sub.

Abstract: A system for controlling the air-fuel ratio of an internal combustion engine includes a transient fuel amount increasing device for regulating the supply fuel amount in the transient state of the engine on the basis of the detection of the transient state of the engine, an air-fuel ratio deviation detecting device for detecting the air-fuel ratio deviation from the optimum air-fuel ratio, and a transient fuel increase amount correcting device for correcting the fuel increase amount in the transient state of the engine in accordance with the air-fuel ratio deviation detected by the air-fuel ratio deviation detecting device. The air-fuel deviation from the optimum air-fuel ratio of the air-fuel mixture upon deposition of a deposit on the back surface of the intake valve is prevented, and the drivability of an automobile is improved.

Abstract: The number of working cylinders of the internal combustion engine is controlled so that the load of the internal combustion engine is relatively increased thereby to keep the combustion effect within an expected range. By controlling the number of working cylinders of the internal combustion engine also to other than integral numbers, the torque control of large freedom is continuously effected. Thus the torque characteristic is smoothed, thus improving the fuel efficiency and driveability at the same time.

Abstract: An apparatus for measuring the flow rate of a gas wherein resistance wires whose resistance value changes in accordance with temperature are arranged in a flow rate measuring tube providing a path of a gas to be measured, a voltage is applied to the resistance wires to detect the change in resistance value of the resistance wires due to the change in temperature thereof in accordance with the gas flow rate, and the flow rate of the gas is measured. In order to support the resistance wires in the flow rate measuring tube, the support members for supporting the resistance wires have respectively two support rods provided with grooves at positions corresponding to the turning points of the resistance wires wound thereon so that the resistance wires are supported stably lying in the grooves.

Abstract: In a differential amplifier circuit, there are provided a chopper circuit for converting an input signal into an AC signal intermittently, an amplifier circuit for amplifying the output of the chopper circuit, a sample hold circuit for taking out a signal corresponding to the input signal out of the output of the amplifier circuit and an oscillator circuit for generating a pulse signal for controlling the chopper circuit and the sample hold circuit. The amplifier circuit includes an operational amplifier having an input terminal connected with a grounding resistor to which selected one of the potentials of said two input terminals is applied.

Abstract: A gas flow measuring device has a measuring circuit for measuring the flow of gas based on the output signals of an electric heater and a first and a second temperature dependent resistor. In the measuring circuit, the first and the second temperature dependent resistors, together with first and second reference resistors, form a bridge and a constant voltage is applied to a voltage at one diametrical point of the bridge. The difference between the other voltage of the diametrical point of the bridge and the output of the constant voltage adding circuit is amplified, and the output voltage of the amplifier circuit is further amplified so that the voltage applied to the electric heater and the bridge is feed-back controlled.

Abstract: In the range where the fuel efficiency may be improved by relatively increasing the load of working cylinders at the time of partial loading of a multicylinder internal combustion engine, the intake pressure of the engine is maintained at a fixed optimum value. Also, the number of working cylinders is controlled, so that a torque actually required by the driver is obtained, and under any load, the maximum improvement of fuel efficiency may be attained at a saving of fuel consumption.

Abstract: In a fluid flow rate measuring apparatus having a sensor including an electric heater resistance wire and first and second temperature dependent resistance wires and a measuring circuit, each of the resistance wires is wound to be held firmly in place on a supporting member made of an electrical insulating material, and the electric heater resistance wire and the first temperature dependent resistance wire, which is responsive to the temperature of the fluid under measurement heated by the electric heater resistance wire, are wound on the same supporting member alternately and close to each other so that the winding direction thereof makes an angle from 60.degree. to 120.degree. to the direction of the flow of the fluid under measurement. Further, each of the supporting members is constructed and arranged so as to minimize the influence of the heat capacity thereof and also to avoid the occurrence of turbulence in the flow of the fluid which is detrimental to the flow rate measurement.

Abstract: A first temperature dependent resistor and a second temperature dependent resistor are disposed within a single gas passage defined by a branch pipe extending into a conduit for a gas whose flow rate is to be measured. An electric heater is located between these temperature dependent resistors and is heated for the purpose of measurement of the flow rate of the gas. A first reference resistor and a second reference resistor constitute a bridge circuit together with the first and second temperature dependent resistors, and the difference between the potentials at the terminals of the bridge circuit is amplified by a first differential amplifier circuit. The difference between the output voltage of the first differential amplifier circuit and a predetermined reference voltage is then amplified by a second differential amplifier circuit.

Abstract: A gas flow rate measuring apparatus for measuring the intake air flow rate of an automobile engine or the like is disclosed, which comprises a flow rate measuring tube containing an electric heater resistance wire and two temperature-dependent resistance wires, one subject to the effect of heat of the electric heater and the other free from the effect. An output signal of a voltage divider circuit including the series-connected temperature-dependent resistance wires is used to measure the gas flow rate. The electric heater resistance wire and the temperature-dependent resistance wire thermally affected thereby are wound side by side but avoiding occurrence of any short-circuit therebetween on a single support member of an electrically insulating material.

Abstract: An electric heater connected between first and second temperature dependent resistors provided inside a pipe through which the gas the flow of which is to be measured is heated for the measurement of the gas flow. A voltage control circuit controls the voltage applied to or current through the electric heater such as to maintain a constant potential difference between diagonal points of a bridge circuit which is formed by the first and second temperature dependent resistors and first and second reference resistors. An output computing circuit which receives a signal proportional to the voltage across the electric heater and also to the current therethrough produces an output signal representing the rate of flow of gas being measured.

Abstract: A gas flow measuring apparatus for measuring intake air flow for an automobile engine having an electrical heater resistive member, and first and second temperature dependent resistive members. The first resistive member is located so as to be well influenced by heat from the heater resistive member, while the second resistive member is located so as to be little influenced by the same. The measuring apparatus measures a gas flow rate by using an output signal from a voltage dividing circuit as a series circuit of the first and second resistive members. In the gas flow measuring apparatus, a heater film resistive member is deposited on a first support member by an evaporation depositing or printing process, and is further covered with electric insulating material such as glass.

Abstract: A first temperature dependent resistor, an electric heater and a second temperature dependent resistor are arranged in this order within and from the downstream to the upstream of a pipe in which flows a gas whose flow rate is to be measured. A bridge circuit is formed by the first and second temperature dependent resistors along with first and second reference resistors. In response to the output of the bridge circuit, a measuring circuit regulates the supply of power to the electric heater and generates a signal indicative of the flow rate of the gas. Each of the first and second reference resistors is in the form of a film resistor formed on an insulating base. The insulating base having the film resistors formed thereon is placed for example in the flow of the gas to be measured.

Abstract: A gas flow measuring apparatus includes first and second temperature dependent resistors located in a gas tube respectively downstream and upstream of an electric heater which is also located in the gas tube. The first and second temperature dependent resistors are connected to form a bridge circuit together with first and second reference resistors. Between a pair of diagonal junctions of the bridge circuit, a potential difference is produced depending on the flow rate of the gas and the power supplied to the electric heater, and a measuring circuit controls the power supplied to the electric heater so that the potential difference is maintained at a predetermined value irrespective of a change in flow rate of the gas.

Abstract: A first temperature dependent resistor and a second temperature dependent resistor are disposed within a pipe for flowing a gas whose flow rate is to be measured. An electric heater is located between these temperature dependent resistors and is heated for the purpose of measurement of the flow rate of the gas. A first reference resistor and a second reference resistor constitute a bridge circuit together with the first and second temperature dependent resistors. A measuring circuit controls the current or voltage applied to the electric heater in accordance with the voltage between the terminals of the bridge circuit, so as to generate an output signal representing the flow rate of the gas. The temperature coefficient resistance of the electric heater is smaller than that of the temperature dependent resistors.