Abstract: An output correction method for an exhaust gas ingredient-concentration sensor for internal combustion engines. The sensor has two sensor elements having output characteristics different from each other. The sensor elements each produce an output proportional to the concentration of an ingredient in exhaust gases emitted from the engine. The sensor controls the air-fuel ratio of a mixture supplied to the engine to a desired air-fuel ratio by the use of an output from at least one of the sensor elements. First, it is determined whether or not the difference between the desired air-fuel ratio and an actual air-fuel ratio represented by the output of at least one of the sensor elements is smaller than a predetermined value. Then, an output value of one of the sensor elements is corrrected based on an output value of the other of the sensor elements when it is determined that the difference is smaller than the predetermined value.

Abstract: An air-fuel ratio feedback control method for an internal combustion engine in which when the engine is operating in a feedback control region, the concentration of an ingredient in exhaust gases from the engine is detected by an exhaust gas ingredient concentration sensor arranged in the exhaust system of the engine and compared with a reference value, and the air-fuel ratio of an air-fuel mixture to be supplied to the engine is controlled to a desired value in a feedback manner responsive to the result of the comparison. Atmospheric pressure is detected, and the reference value is set to a value depending on the detected value of atmospheric pressure. The reference value is set to a higher value as the detected value of atmospheric pressure is lower. The reference value is set to a lower value when the engine is operating in an idling region than when the engine is operating in a region other than the idling region.

Abstract: A vehicle cruise control system, comprising a control circuit for producing a control signal for maintaining a speed of a vehicle at a fixed level according to a difference between an actual vehicle speed and a target vehicle speed, and a drive circuit for producing a drive signal for selectively driving an actuator in a direction either to accelerate the vehicle or to decelerate the vehicle according to the control signal from the control circuit. The drive circuit is provided with a transistor bridge circuit comprising four drive transistors for producing the drive signal. The control circuit is provided with a detection means for detecting an abnormal state of the system and an inhibiting means which brings at least one of the drive transistors into an non-conductive state when any abnormal state is detected by the detecting means. The control circuit may be programmed to perform a certain diagnostic procedure for testing the soundness of the drive transistors.

Abstract: A method of determining the activation of an exhaust gas ingredient-concentration sensor for use in an internal combustion engine. The air-fuel ratio of a mixture is controlled in a feedback manner by the use of a coefficient varying with an output of the sensor during engine operation in an air-fuel ratio feedback control region. The activation of the sensor is determined based on the output of the sensor. When the engine has shifted from the air-fuel ratio feedback control region to a predetermined decelerating region, calculated is an average value of values of the coefficient obtained by the feedback control immediately before the shifting. The air-fuel ratio of the mixture is leaned by the use of the average value thus calculated. It is determined whether or not the sensor is activated when the air-fuel ratio has thus been leaned.

Abstract: An air-fuel ratio feedback control method for an internal combustion engine, in which when the engine is operating in a feedback control region, the air-fuel ratio of an air-fuel mixture being supplied to the engine is controlled by the use of a correction coefficient varying in response to the output of an exhaust gas ingredient concentration sensor arranged in the exhaust system of the engine. When the engine has shifted to a predetermined high load region within the feedback control region, in which the rate of change in values of an engine operating parameter is larger than a predetermined value, the air-fuel ratio feedback control is effected by the use of a first average value of the correction coefficient, calculated when the engine is in the predetermined high load region.

Abstract: A method of controlling supercharging pressure in an internal combustion engine having a supercharger with an increase rate-varying device for varying the rate of increase of the supercharging pressure. The supercharging pressure is controlled to a desired value in response to the difference between the actual value of the supercharging pressure and the desired value. The increase rate-varying device is held in a position for obtaining the maximum rate of increase of the supercharging pressure while the actual value of the supercharging pressure is below a predetermined value which is lower than the desired value. The predetermined value is set to a lower value as the rate of increase of the supercharging pressure increases, or when a transmission of the engine is in a lower of two or more speed positions of the transmission. Also, the predetermined value of the supercharging pressure is set to a lower value as the actual intake air temperature decreases.

Abstract: A roller clamp type wheel examining apparatus includes a support for supporting thereon a wheel of a vehicle to be examined, a plurality of rollers for clamping the wheel supported on the support from both sides thereof and an angle detector for detecting the angle of orientation of the wheel when clamped by the plurality of rollers. The wheel of a vehicle clamped by the rollers on both sides thereof may be driven to rotate around its own rotating axis to thereby examine dynamic characteristics of the wheel. In this case, the support structure should, for example, include a pair of support rollers for supporting thereon the wheel to be examined in a rotatable manner. The support may include a floating table having a flat top support surface and movable in a horizontal plane translationally as well as rotationally, in which case only the dynamic characteristics of the wheel may be examined since the wheel is not rotatable around its rotating axis.

Abstract: A valve actuating mechanism for an internal combustion engine in which a rotatable cam has its camming surface disposed to slide on a cam slipper surface of a rocker arm to thereby open and close an intake valve (or exhaust valve) of the engine by rocking motion of the rocker arm. The dimensions, shapes, and relative positions of the rotatable cam and the rocker arm are so designed as to satisfy a condition of V.sub.C +V.sub.F >0, where V.sub.C represents the velocity of movement of a contact point on the camming surface at which the camming surface slides on the cam slipper surface, and V.sub.F the velocity of movement of the contact point on the cam slipper surface at which the cam slipper surface slides on the camming surface.

Abstract: An exhaust gas circulation control method for an internal combustion engine in which an exhaust gas recirculating valve is arranged across an exhaust gas recirculating passage extending between the exhaust and intake passages. The opening of the valve is controlled in response to operating conditions of the engine. The exhaust gas circulation is inhibited when the engine load exceeds a predetermined value set in response to the engine temperature such that it is set to a smaller value as the engine temperature is lower.

Abstract: A method of controlling in a feedback manner the air-fuel ratio of an air-fuel mixture supplied to an internal combustion engine having a first fuel injection valve and a second fuel injection valve each operating in a different operating region, during operation of the engine in an air-fuel ratio feedback control region, by the use of a coefficient which varies with the output of an exhaust gas ingredient concentration sensor. In a first and a second operating regions within the air-fuel ratio feedback control region in which the first and second fuel injection valves operate, respectively, a first average value and a second average value of values of said coefficient obtained in the respective regions are calculated, and stored, respectively. When the engine has shifted to the first or and second operating regions, a value based on the corresponding first or second average value is used as an initial value of the coefficient to therely start the feedback control.

Abstract: In a sunroof structure having an opening provided in a roof panel of an automobile, a sunroof panel which can move between a first position for closing the opening and a second position for exposing the opening, a sunroof base panel supporting a mechanism for achieving the motion of the sunroof panel, and a water drain trough defined along a peripheral region of the opening, the water drain trough is defined by a trough member having a substantially U-shaped cross section extending along the peripheral region of the opening and resting upon an inner surface of an outer wall of the sunroof base panel and an outer surface of a guide rail for the sunroof panel. Preferably, the trough member consists of an extension of a seal member which is interposed between a lower surface of the roof panel and an upper most edge of the outer wall of the sunroof base panel. Thus, the trough member is not required to be rigid and the assembly work is simplified.

Abstract: A method of controlling supercharging pressure in an internal combustion engine, wherein the supercharging pressure is controlled by controlling a control amount for operating a supercharging pressure control device. The control amount is controlled in feedback control mode responsive to the difference between the actual value of the supercharging pressure and a desired value thereof when the supercharging pressure is in a steady state, and at the same time a learned value of the correction value is obtained by calculating values of same applied during the feedback control. The control amount is controlled in open loop control mode based upon the learned value when the supercharging pressure is in a transient state. The calculation of the learned value is inhibited when a predetermined condition is satisfied during the steady state. The predetermined condition is satisfied when the desired value of the supercharging pressure is set to a different value than a normal value set during the steady state.

Abstract: In an electrical connector, a male connector body and a female connector body are coupled and locked together to effect the mechanical connection of electrical terminals housed in the respective connector bodies. To prevent incomplete coupling of the relevant connector bodies, a path is formed in the male connector body in such a manner as to correspond to the shape and dimension of a bracket for fixing the electrical connector to the body of an automotive vehicle or components thereof, and a rib is provided on the female connector body in such a manner as to traverse the path. This rib blocks a part of the path when the two connector bodies are improperly coupled with each other, thus making it possible to detect incomplete coupling. An electrical connector of another type has another configuration for the same purpose.

Abstract: Nodular cast iron having favorable mechanical properties, in particular a high impact strength at low temperatures, comprising: from 3.0 to 4.0% of carbon; from 1.5 to 2.3% of silicon; less than 0.3% of manganese; not more than 0.03% of phosphorus; less than 0.10% of chromium; from 0.02 to 0.06% of magnesium; and from 0.0015 to 0.0150 weight % of bismuth with the balance consisting of iron and inevitable impurities and the CE (carbon equivalent) value being from 3.9 to 4.6%. This material is characterized by a low silicon content. Adding from 0.5 to 2.0% of nickel thereto improves its tensile strength and yield strength. Preferably, from 0.005 to 0.03% of bismuth is added to this nodular cast iron in molten state so as to produce more than 300 graphite nodules per mm.sup.2. The remaining bismuth content is preferably from 0.0015 to 0.015%, more preferably from 0.0015 to 0.004%.

Abstract: To the end of eliminating the problems arising from substantially rigid connection between a front wheel set and a rear wheel set in a four-wheel drive vehicle, there is provided a power transmission system in which a speed-dependent power transmission device is provided between the front wheel set and the rear wheel set so that both the wheel sets are substantially rigidly connected to each other in a low speed range and rotational power is transmitted only from the front wheel set to the rear wheel set in a high speed range.

Abstract: Conventionally, heat treatment was necessary in the final stage of producing nodular cast iron products to give the nodular cast iron with desired mechanical properties. This was necessary because of the loss of graphitization capability of the molten metal when it is being formed into nodular cast iron during the process of spheroidization, and the heat treatment is therefore required to decompose cementite formation and thereby promote graphitization. The process of producing nodular cast iron according to the present invention can achieve the promotion of graphitization and the increase in the number of graphite nodules, which are both important for the production of high-quality thin-shell cast iron products, through the synergetic effect of processing the molten metal with a graphitization agent such as SiC or CaC.sub.2 and of adding a graphite atomization agent such as Bi.

Abstract: A vehicle cruise control system having an electric actuator for acting upon a throttle valve of a vehicle, a clutch for disconnecting the actuator from the throttle valve, a spring or the like for returning the output end of the clutch to a neutral state and a limit switch for detecting the limit of the motion of the output end of the clutch and discontinuing the supply of electric current to the actuator upon detection of the limit. Since the detection of the lower limit of the stroke of the actuator for decelerating the vehicle is necessary for preventing unnecessary supply of electric current to the actuator and overloading of the actuator, the closed state of the limit switch is tested by supplying an electric current to the actuator so as to decelerate the vehicle prior to starting the normal operation of the vehicle cruise control and determining if the electric current is indeed conducted through the actuator or not.

Abstract: A method of controlling the air-fuel ratio of a mixture being supplied to an internal combustion engine, in a feedback manner responsive to an output signal from an O.sub.2 sensor arranged in the engine exhaust system for sensing the concentration of a component in exhaust gases from the engine to produce as the output signal a normally fluctuating output signal indicative of the concentration. The air-fuel ratio is controlled to a desired value by means of at least one of proportional control applying a first correction value to correct the air-fuel ratio when the output signal changes from a rich side to a lean side or vice versa with respect to a predetermined reference value, and integral control applying a second correction value to correct the air-fuel ratio whenever a predetermined period of time elapses so long as the output signal remains on the lean side or on the rich side with respect to the predetermined reference value.

Abstract: A method of controlling the air-fuel ratio of a mixture of fuel supplied to an internal combustion engine. Feedback control is effected to response to an output from an exhaust-gas concentration sensor to bring the air-fuel ratio to a predetermined value when the engine is in a predetermined medium-load operating region. It is determined whether or not the engine is in a predetermined high-load operating region in which the feedback control is interrupted for bringing the air-fuel ratio to a value smaller than the predetermined value, and whether or not the engine is in a predetermined low-load operating region in which the feedback control is interrupted for bringing the air-fuel ratio to a value larger than the predetermined value.

Abstract: An operation control system for an internal combustion engine includes a first current detector for detecting a value of electric current flowing in a field winding of an AC generator of the engine, and an ECU responsive to the detected value of electric current for determining a control amount by which the operation of the engine is to be controlled, and for changing output torque of the engine in response to the determined control amount. A second current detector, preferably, a Hall element, detects a value of electric current flowing from the AC generator to electrical loads on the engine. The ECU detects a transient state of the electrical loads, based upon the detected value of electric current from the second current detector. The ECU is operable when the transient state is detected, for determining a transient correction amount of the determined control amount, in response to the detected value of electric current from the first current detector.