Abstract: A mold casting process comprises, after pouring of a molten metal into a mold, rapidly cooling that surface layer of a cast product which is in contact with a mold, and releasing the resulting product from the mold when the surface layer thereof has been converted into a shell-like solidified layer. Such process is used for casting a mechanical part blank and apparatus for carrying out the process is provided.

Abstract: Deterioration of an exhaust gas concentration sensor for an internal combustion engine is detected by integrating a difference between an output from the exhaust gas concentration sensor and a predetermined reference value which is outside a range of the output which can be assumed during normal operation of the exhaust gas concentration sensor, comparing a thus obtained integral value with a predetermined deterioration-determining value, and determining from the result of the comparision whether the exhaust gas concentration sensor is deteriorated.

Abstract: An improved method of determining activation of an exhaust gas concentration sensor for detecting the concentration of an exhaust gas ingredient in exhaust gases from an internal combustion engine. The sensor comprises an exhaust gas ingredient-detecting element, and a heater for heating the element. An output signal from the sensor is used for air-fuel ratio feedback control of an air-fuel mixture supplied to the engine. It is determined that activation of the sensor has been completed when an output voltage from the sensor has become lower than a predetermined activation-determining reference voltage. The predetermined activation-determining reference voltage is changed depending on a time period over which the heater has been energized while the engine is in an operating condition under which the air-fuel ratio feedback control should be carried out.

Abstract: A method of controlling the air-fuel ratio of an air-fuel mixture supplied to an internal combustion engine including the step of interrupting the feedback control of the air-fuel ratio responsive to a detected value of the concentration of an exhaust gas ingredient after a high load operating condition of the engine in which a detected load on the engine is above a predetermined reference value has continued over a predetermined time period. Calculation is made of a value of a parameter dependent on a ratio of a time period over which the detected load on the engine continued to be above a predetermined value to a time period over which the detected load on the engine continued to be below the predetermined value. The predetermined time is set based on the calculated value of the parameter dependent on the ratio. The predetermined value may be equal to the predetermined reference value, or alternatively may be smaller than the predetermined reference value.

Abstract: An information display system for a vehicle includes: a plurality of sensors for detecting various conditions of the vehicle; a display unit for displaying a selected one of a plurality of items of information relating to the conditions of the vehicle as detected by the corresponding sensors; a pair of manual for sequentially shifting the item of information which is currently displayed on the display unit; and a control unit for producing one of the items of information on the display unit according to output from one of the sensors. The control unit is further adapted to change the item of information which is currently displayed to a display of a default item of information, when the current display was manually selected, upon elapsing of a certain time interval after the manual selection of the current item of information for display.

Abstract: A steering angle detecting system for a vehicle includes a sensor responsive to rotation of a steering wheel for generating angular pulses corresponding in number to the steering angle of the steering wheel. Another sensor generates a reference pulse at a predetermined angle of the steering wheel. The angular pulses are counted by a counter. The steering angle detecting system is determined to be abnormal if the counted value of the counter is not within a predetermined value range when the reference pulse is generated. Further, the rate of change of the counted value by the counter is detected, and the steering angle detecting system is determined to be abnormal if the detected rate of change of the counted value is greater than a predetermined value. Further, the steering angle detecting system is determined to be abnormal if the detected rate of change of the counted value has continued to be smaller than a predetermined value for a predetermined time period or longer.

Abstract: An operation control system for internal combustion engines at and after starting has an engine temperature sensor, a control valve for controlling the amount of intake air to be supplied to the engine, and a valve opening determining device responsive to an output from the engine temperature sensor for determining the opening of the control valve. The valve opening determining device sets the opening of the control valve at the start of the engine to a value such that the intake air amount is smaller as the engine temperature is lower. A fuel amount determining device is responsive to the output from the engine temperature sensor for determining the amount of fuel to be supplied to the engine at starting. A correction value determining device is responsive to the opening of a throttle valve of the engine for determining a correction value for the fuel amount in such a manner as to increase the fuel amount at a larger rate as the throttle opening is larger.

Abstract: An output correction method for a proportional-output type O.sub.2 sensor including an oxygen concentration detecting element formed by an oxygen-pumping element and a cell element, each of the oxygen-pumping element and the cell element being composed of a wall of a solid electrolytic material having oxygen ion-conductivity, and a pair of electrodes having the wall interposed therebetween. The oxgen-pumping element is supplied with an output voltage corresponding to a difference between a voltage developed between the electrodes of the cell element and a predetermined reference voltage, and current flowing in the oxygen-pumping element is detected. A correction resistance supplies information indicative of a deviation of an air-fuel ratio detected by the sensor with respect to a predetermined reference air-fuel ratio. A correction value is determined on the basis of the information and the direction of flow of the current. The detected current is corrected by the use of the determined corrected value.

Abstract: An output control system for an internal combustion engine for an automotive vehicle having a variable capacity type compressor installed therein and driven by the engine, in which the output torque of the engine is increased by means of an engine output incremental value in response to operation of the compressor. Load torque produced by the compressor is detected through the piston stroke and discharge pressure of the compressor, and the engine output incremental value is set depending on the detected load torque. The engine output incremental value is also set depending on the engine rotation speed.

Abstract: A fuel supply control system for an internal combustion engine in which an accelerating fuel increment of fuel supplied to the engine is set in response to the detected change rate in the opening degree of the throttle valve. Further, the accelerating fuel increment is set in such a manner that it is smaller as the detected reduction gear ratio of the transmission is larger. Advantageously, the accelerating fuel increment is set to increase at a smaller rate as the above detected change increases within a region within which the change rate is smaller than a region in which the change rate is larger.

Abstract: A method of controlling supercharging pressure in an internal combustion engine wherein the supercharging pressure created by a supercharger is controlled based on a basic control amount determined in dependance on operating conditions of the engine. The basic control amount is corrected in response to the difference between an actual value of the supercharging pressure and a desired value thereof when the engine is in a feedback control region. The basic control amount is corrected in accordance with the rate of change of the supercharging pressure when the engine is in an operating condition immediately before the feedback control region. The supercharging pressure is controlled based upon a second basic control amount other than the first-mentioned basic control amount when the supercharging pressure is below a predetermined value determined by the engine rotational speed and the rate of change of supercharging pressure in the above operating condition.

Abstract: A mold casting process comprises, after pouring of a molten metal into a mold, rapidly cooling that surface layer of a cast product which is in contact with a mold, and releasing the resulting product from the mold when the surface layer thereof has been converted into a shell-like solidified layer. Such process is used for casting a mechanical part blank and apparatus for carrying out the process is provided.

Abstract: A fuel supply control system for an internal combustion engine, wherein when the engine is at idle, a correction value is determined based on a difference between a desired idling engine rotational speed and an actual engine rotational speed, and an amount of fuel to be supplied to the engine is corrected by the determined correction value. Correction value-changing means sets a rate of change in the correction value relative to a change in the difference to a greater value when the detecting means detects that the engine means is not engaged with the transmission of an automotive vehicle, and to a smaller value when the detecting means detects that the engine is engaged with the transmisison.

Abstract: An air-fuel ratio control method for an internal combustion engine having an exhaust gas-ingredient concentration sensor provided in an exhaust system and generating an output proportional to the concentration of an ingredient in exhaust gases emitted from the engine. The air-fuel ratio of a mixture supplied to the engine is controlled to a desired air-fuel ratio corresponding to an operating condition in which the engine is operating, in a feedback manner responsive to the output of the sensor. Supply of fuel to the engine is interrupted while the engine is in a predetermined decelerating condition. The method comprises the steps of progressively decreasing the desired air-fuel ratio from a value larger than a value corresponding to the operating condition of the engine to the latter value after the engine leaves the predetermined decelerating condition, and controlling the air-fuel ratio of the mixture supplied to the engine to the progressively decreased air-fuel ratio in the feedback manner.

Abstract: A method of detecting failure of an exhaust gas component concentration sensor for detecting concentration of a component of exhaust gases from an internal combustion engine. The method comprises the steps of: (1) applying a predetermined voltage to the sensor, (2) determining whether or not a change in an output voltage from the sensor caused by the application of the predetermined voltage to the sensor is smaller than a predetermined value, and (3) deciding that the sensor is faulty when the change in the output voltage is smaller than the predetermined value. A device for sensing concentration of a component of exhaust gases from an internal combustion engine comprising an electric resistance member connected in series between an electric current supply source and one of a pair of electrodes provided on a solid electrolytic element.

Abstract: An electronically-controlled fuel injection system for internal combustion engines. When the engine is in an accelerating condition, an amount of fuel supplied to the engine is increased by means of an incremental value. It is discriminated whether or not a predetermined time period has elapsed from the time the rotational speed of the engine increased above a predetermined value, or from the time gear shifting was completed, while the engine is in the accelerating condition. The incremental value is limited to a predetermined upper limit if the former exceeds the latter before the lapse of the predetermined time period, whereby sudden increase in the engine rotational speed can be prevented.

Abstract: A method of determining the deterioration of an oxygen concentration sensor for an internal combustion engine. The oxygen concentration sensor includes at least one oxygen concentration sensor element having an oxygen-pumping element and a cell element each composed of a member of a solid electrolytic material having oxygen ion-conductivity, and a pair of electrodes having the member interposed therebetween, and a current-detecting resistance serially connected to the oxygen-pumping element to form a series circuit. A voltage having a magnitude corresponding to a difference between a voltage produced between the electrodes of the cell element and a predetermined reference voltage is applied to the series circuit, and pumping current is detected from a voltage developed across the current-detecting resistance.

Abstract: An air-fuel ratio control method for an internal combustion engine, wherein when the engine is in a feedback control region, a value of concentration of oxygen detected by the O.sub.2 sensor is compared with a predetermined reference value, and the air-fuel ratio of a mixture being supplied to the engine is controlled to a desired value in a feedback manner responsive to the comparison result. When the engine is in a predetermined high load operating region, the feedback control is interrrupted and an amount of fuel to be supplied to the engine is increased by a predetermined amount to thereby enrich the air-fuel ratio. The predetermined amount is increased when the engine is in the predetermined high load operating region and at the same time the detected oxygen concentration indicates that the air-fuel ratio is on a lean side with respect to the desired value.

Abstract: A method of controlling supercharging pressure in an internal combustion engine by means of a basic control amount dependent upon operating conditions of the engine. A change rate of the supercharging pressure is detected. When the supercharging pressure is in a transient state where it is increasing, the basic control means is corrected in response to the detected change rate of the supercharging pressure, in such a manner that the supercharging pressure increases at a predetermined rate.

Abstract: A method of controlling in a feedback manner the air-fuel ratio of an air-fuel mixture being supplied to an internal combustion engine of the type that vaporized fuel is supplied from a fuel supply system to an intake system thereof. The air-fuel ratio is controlled by the use of a correction value which varies in response to an output from an exhaust gas ingredient sensor, and the maximum or minimum value of which is limited to an upper or lower limit value. The pressure of the vaporized fuel in the fuel supply system is sensed, and at least one of the upper and lower limit values is set in accordance with the sensed pressure of the vaporized fuel. Further, the air-fuel ratio is controlled by the use of an average value of the correction value. The pressure of the vaporized fuel in the fuel supply system is sensed, and the calculation of the average value is inhibited when the sensed pressure of the vaporized fuel is higher than a predetermined value.