Abstract: An internal combustion engine has a plurality of cylinders and intake passages leading to the cylinders respectively. A plurality of intake control valves block and unblock the intake passages respectively. Drive devices open and close the intake control valves mutually-independently. A detecting device serves to detect a predetermined condition of the engine under which a speed of the engine is required to vary. A control device performs a control of closing the intake control valves mutually-independently by use of the drive devices after the detecting device detects the predetermined condition of the engine.

Abstract: An intake apparatus for an internal combustion engine that has a first intake passage communicating with a combustion chamber of the internal combustion engine; a second intake passage which communicates with the combustion chamber of the internal combustion engine and whose length is greater than a length of the first intake passage; a valve for selectively changing over the communication/shutting off of the combustion chamber of the internal combustion engine with/from between the first or/and second intake passages; and a drive circuit for driving the valve to effect the changing over operation. A controller controls the drive circuit, and an air cleaner device introduces clean air into the combustion chamber of the internal combustion engine.

Abstract: An intake control system includes an intake control valve disposed in a common intake pipe connected to engine cylinders or a plurality of intake control valves disposed in intake pipes connected respectively to the engine cylinders. The intake control valves are openable and closable under the control of an electronic control unit directly or through respective actuators, based on an electric signal indicative of an operating condition of intake valves on engine cylinders.

Abstract: The flow rate of intake air in an engine, engine speed, and automobile speed are detected. The speed-change ratio of a transmission is determined and adjusted in response to a signal which is proportional to the detected intake air flow rate and inversely proportional to the detected engine speed, and in response to the detected automobile speed.

Abstract: A filter for an air cleaner is produced by impregnating a fiber web composed of one or more layers with a liquid binder in the form of solution, suspension, or emulsion. The impregnated fiber web is dried such that the solvent or dispersing medium on one side evaporates faster then that on the other side. As the result, more binder is deposited on one side than on the other side; in other words, a gradient of binder distribution is formed. The thus-produced filter has such a structure that the voids among fibers continuously change across the thickness, while fibers are bonded together by the binder. The filter thus produced can collect more dust than a conventional one.

Abstract: A gas-flow measuring apparatus including a semiconductor chip and a sensing circuit. The semiconductor chip includes an electric heater and two temperature-detecting elements. One of the temperature-detecting elements is located closer to the heater than the other. The sensing circuit generates voltage in response to the flow rate of gas flowing through a gas passage.

Abstract: In an internal combustion engine, a plurality of engine rotational speeds are detected at predetermined timings for every firing stroke in one cylinder of the engine, and an engine speed variation is calculated as a variation between the square of one of the engine rotational speed and the square of another of the engine rotational speed. A process is performed upon the sequence of the engine speed variations, thus determining an engine combustion state by the processed result.

Abstract: A semiconductor type flow rate detecting apparatus having first and second control units arranged at upstream and downstream positions respectively in a flow stream to be measured and an operation circuit. The first control unit includes a first temperature detecting element and a first temperature control heater. The second control unit includes a second temperature detecting element, a second temperature control heater and a preliminary heater. The operation circuit controls the second and preliminary heaters and generates a signal indicative of flow rate. The operation circuit has a constant power consumption circuit to control heat from the preliminary heater to a constant level.

Abstract: In a semiconductor-type flow rate detecting apparatus, a casing arranged in the fluid path includes first and second semiconductor chips. The first semiconductor chip has a first temperature detector. The second semiconductor chip arranged in proximity to the first semiconductor chip has a heater and a second temperature detector.

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: 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: 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: 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: A torque detector for detecting a torque applied to a torque transmission shaft which is connected to a load such as a wheel of an automobile. A first rotating body is connected to one end of a driving shaft of an engine coaxially, and an annular second rotating body is disposed around a boss which projects from the center of the first rotating body so as to be coaxial and parallel with the first rotating body. An elastic member connects the inner peripheral portion of the second rotating body to the boss in the radial direction. The angular phase difference between the first and the second rotating bodies which occurs due to the deformation of the elastic member is detected, and torque is calculated from the obtained angular phase difference.

Abstract: A gas-flow measuring apparatus including a plurality of thermocouples formed in series on a substrate. Every other thermojunction of the thermocouples is located upstream of an electric heater, while the remaining thermojunctions of the thermocouples are located downstream of the electric heater.

Abstract: In an internal combustion engine, a standard deviation of combustion variations generated for every firing stroke of at least one cylinder is calculated. The misfire limit of the engine is detected by determining whether or not the calculated standard deviation is greater than a reference value. When the calculated standard deviation is greater than the reference value, the controlled air-fuel ratio is decreased, while when the calculated standard deviation is not greater than the reference value, the controlled air-fuel ratio is increased, thereby attaining a lean burn system without a lean mixture sensor.

Abstract: A torque detector, particularly a torque detector for detecting a torque applied to a torque transmission shaft which is connected to a load such as a wheel of an automobile, has a driving member connected to an engine, a driven member connected to a load and driven by the driving member to be rotated, an elastic member for connecting the driving member to the driven member, a transmission for varying the rotating speed ration of the engine to the load, which is provided in the driving member or the driven member, electromagnetic pickups for detecting the angular phase difference between the driving member and the driven member which is produced due to the deformation of the elastic member, a rotating speed ratio counting circuit for detecting the rotating speed ratio of the engine to the load, which is controlled by the transmission, and a microcomputer for calculating engine torque and load driving torque from the rotating speed ratio detected by the rotating speed ratio counting circuit and the angular pha

Abstract: A signal converting apparatus for converting voltage into a pulse signal with a corresponding pulse-width comprises a switching circuit for selecting either one of an input voltage to be converted or a constant voltage depending upon a binary switching signal. The selected voltage is integrated with respect to time by an integrating circuit. When the output from the integrating circuit has reached an upper limit voltage or a lower limit voltage, the above-mentioned binary switching signal which is an output signal of this signal converting apparatus is inverted by a comparator/inverter circuit.

Abstract: In a fuel supply control apparatus for an internal-combustion engine, liquid fuel is vaporized and is supplied to a fuel gas passage leading to an intake air passage. The flow rate of the vaporized fuel flowing through the fuel gas passage is detected, and the flow rate of the fuel is calculated in accordance with the load of the engine. As a result, feedback control of the fuel to be supplied to the engine is carried out so that the detected flow rate of the vaporized fuel is close to the calculated flow rate of the fuel.

Abstract: In a method for measuring variations in the output of an internal combustion engine, at least one of signals respectively representing an engine speed, torque, and internal cylinder pressure of the internal combustion engine during the firing strokes of the engine is obtained. A periodical and pulsating change in the obtained signal is detected. A differential value at a portion of the change of the signal having a maximum gradient is then detected. Another method provides measuring variations in the output of the internal combustion engine by calculating the difference between the maximum and minimum values of the change of the obtained signal. Still another method provides measuring variations in the output of the internal combustion engine by correcting the obtained value in accordance with the engine speed. Still another method provides measuring variations in the output of the internal combustion engine by calculating the difference between consecutive changes.