Abstract: A frictionally engaging device for power transmission of a vehicle, has a first pressure chamber defined in part by one side of a piston urging frictionally engaging elements into engagement with each other, and a second pressure chamber defined in part by the other side of the piston for accommodating the frictionally engaging elements. A hydraulic pressure control arrangement controls operating fluid pressure supplied to the first pressure chamber at least to a value higher than a first predetermined value which causes engagement of the frictionally engaging elements and to a second predetermined value lower than the first predetermined value, which inhibits creeping of the frictionally engaging elements. When the operating fluid pressure is lower than the second predetermined value, a first valve opens to allow escape of the operating fluid from the second pressure chamber to the first pressure chamber.

Abstract: An ignition timing control method for an internal combustion engine wherein a plurality of correction values for ignition timing are stored in memory means beforehand as a function of an output voltage from a variable voltage creating means which is humanly adjustable and the rotational speed of the engine. The output voltage from the variable voltage creating means and the rotational speed of the engine are detected, and one of the correction values is read, which corresponds to the detected output voltage and the detected rotational speed of the engine. Then, the ignition timing is corrected by the use of the read one correction value. Further, a value of a parameter indicative of load on the engine is detected, and the ignition timing control is executed when the detected value of the parameter is above a predetermined value. Alternatively, in place of the correction values, address values are stored in memory means.

Abstract: A method of effecting feedback control of the air-fuel ratio of an air-fuel mixture being supplied to an internal combustion engine, by correcting a basic fuel supply quantity by the use of a correction coefficient variable in response to the output of an exhaust gas ingredient concentration sensor. An engine low-load operating region is defined by at least one parameter representing load on the engine. When the engine enters the low-load operating region, a value of the correction coefficient is determined in response to an output from the above sensor and also an average value of values of the correction coefficient thus determined is calculated for a predetermined time period after the engine enters the low-load operating region. A target value of the correction coefficient is calculated on the basis of the average value obtained, the target value yielding a predetermined air-fuel ratio higher than a stoichiometric mixture ratio.

Abstract: A vacuum-operated actuator controls opening and closing of a throttle valve in an intake passage of an internal combustion engine in response to pressure in a vacuum chamber thereof. A change-over control valve supplies the vacuum chamber, selectively, with first and second control pressures for opening and closing the throttle valve, respectively. An electronic control unit controls the engine idling rotational speed by generating an on-off control pulse signal having a period corresponding to the engine rotational speed, and supplying the change-over control valve with the on-off control pulse signal to cause same to supply the vacuum chamber with the first or second control pressure.

Abstract: A fuse circuit unit for combination with an electromagnetic switch has a first terminal having one end thereof adapted to be connected to one terminal of a main fuse of a load circuit, and another end adapted to be connected to of the input terminal of the electromagnetic switch. The fuse circuit unti also has a second terminal having one end thereof adapted to be connected to another terminal of the main fuse, and another end adapted to be connected to the load circuit, and a casing supporting the first and second terminals. The casing of the fuse circuit unit is engageable with the electromagnetic switch, and the first terminal of the fuse circuit unit is removably fastened to the input terminal of the electromagnetic switch to mechanically and electrically connect them together. The casing is molded from a resin in a one-piece body, together with the first and second terminals.

Abstract: An operation control system for an internal combustion engine includes a mechanically connecting device connecting between an accelerator pedal and a throttle valve and operable such that an amount of change in the valve opening of the throttle valve relative to a change in the stepping amount of the accelerator pedal is smaller in a smaller stepping amount region than in a larger stepping amount region. A throttle valve opening sensor is adapted to generate as actual throttle valve opening an output signal directly proportional in valve to a stepping amount of the accelerator pedal. A control unit is responsive to the output signal from the throttle valve opening sensor for controlling an operating amount of the operation control system.

Abstract: A supplementary light device for use with a motorcycle including a fairing covering at least front and front lower areas of a main frame structure thereof and having a bifurcated and depending part extending downwardly on either side of the main frame structure. The supplementary light device is adapted to be incorporated integrally in the bifurcated and depending part of the fairing.

Abstract: A hydraulic type starting clutch having an input rotating member rotatable in unison with an input shaft, an output rotating member rotatable in unison with an output shaft, and friction plates interposed between the input and output rotating members and adapted to transmit torque from the input rotating member to the output rotating member when engaged. An urging member urges the friction plates to cause transmission of torque from the input rotating member to the output rotating member, and a hydraulic pressure chamber is defined between the urging member and the output rotating member and supplied with a hydraulic fluid from a hydraulic fluid source. A control device controls a pressure regulating valve in a manner such that the pressure in the hydraulic pressure chamber is regulated to values dependent upon the rotational speed of the input shaft.

Abstract: A method of controlling an exhaust gas recirculating quantity in an internal combustion engine, which is adapted to detect, by a valve opening sensor, actual valve opening of an exhaust gas recirculating valve arranged across an exhaust gas recirculating passageway communicating the exhaust passage of the engine with the intake passage of same, calculate the difference between the detected actual valve opening value and a desired valve opening value set in response to operating conditions of the engine, and actuate the exhaust gas recirculating valve to close or open by operating a valve actuator so as to minimize the difference. When a time interval at which the sign of the difference between the actual valve opening value and the desired valve opening value has been inverted exceeds a predetermined period of time, it is determined that the exhaust gas recirculation control system including the valve opening sensor has developed an abnormality.

Abstract: A method of detecting abnormality in a reference crank angle position detection system of a control system for controlling an internal combustion engine, the control system using at least reference pulses generated, respectively, at predetermined crank angles of the crankshaft and detected by the detection system, and crank angle pulses generated, respectively, at predetermined angles of the crankshaft and with a pulse repetition period shorter than that of the reference pulses, for controlling the engine. Counting of crank angle pulses is started from the time each reference pulse is generated. It is determined whether or not one reference pulse has been generated between an immediately preceding crank angle pulse and a present one, when the counted value is equal to a predetermined value. If not, it is decided that abnormality exists in the occurrence of reference pulses.

Abstract: A creep-inhibiting device for use in an automotive vehicle equipped with a transmission mechanism coupled in series to a fluid coupling and having a frictionally engaging element. Control means interposed between the frictionally engaging element and an operating fluid source controls the power transmission capacity of the frictionally engaging element within a range from substantially zero to a predetermined value in dependence on a signal fluid pressure representative of engine load, to inhibit creeping of the vehicle when the vehicle engine is in a no-load state. The control means has a valve body selectively connecting and disconnecting an input fluid line to and from an output fluid line. A first pressure chamber defined by a first end face of the valve body is supplied with an operating fluid pressure in the output fluid line, while a second pressure chamber defined by a second end face of the valve body is supplied with the signal fluid pressure.

Abstract: In a transmission for an automotive vehicle, a control system for a direct-coupling mechanism for mechanically engaging input and output members of a hydraulic power transmission. An operating fluid pressure regulator controls operating fluid pressure applied to a hydraulically operating portion of the direct-coupling mechanism, and the direct-coupling mechanism applies an engaging force corresponding to the operating fluid pressure thus controlled to the input and output members. A vehicle speed sensor detects the speed of the vehicle, and a slip sensor detects the value of a predetermined parameter indicative of an amount of relative slip between the input and output members.

Abstract: An intake air quantity control method for an internal combustion engine at idle. A supplementary air quantity to be supplied to the engine through a first auxiliary air passage bypassing an engine throttle valve is controlled by a first control valve on the basis of a basic value of a control amount corresponding to the difference between actual engine speed and desired idling speed. A supplementary air quantity to be supplied to the engine through a second auxiliary air passage is controlled by a second control valve in response to engine temperature. A first correction value is calculated based upon detected atmospheric pressure encompassing the engine, and a second correction value based upon detected engine temperature and atmospheric pressure, respectively. The basic value of the control amount is corrected by means of the first and second correction values, and the first control valve is driven according to the corrected control amount basic value.

Abstract: A plurality of heat radiating passages are juxtaposed to each other. A fluid distributing chamber and a fluid collecting chamber are disposed at respective opposite ends of the radiating passages in communication therewith. The heat radiating passages each having a substantially U-shaped configuration and extending in the same directions with each other so that the fluid distributing chamber and the fluid collecting chamber are closely juxtaposed to each other.

Abstract: A theftproof device comprising a flexible tying member, an optical fiber extending through the flexible tying member, a light emission element arranged opposite an end of the optical fiber, a light receiving element arranged opposite the other end of the optical fiber, a fixture fixed to an object to be protected from theft, an electrical circuit arranged within the fixture, mechanical connector means for mechanically connecting the flexible tying member to the fixture, and electrical connector means for electrically connecting the light emission element and the light receiving element to the electrical circuit. The electrical circuit is responsive to a change in a photo signal generated by the light emission element and transmitted through the optical fiber, for performing a warning function.

Abstract: A method of detecting an abnormality in a system for detecting the concentration of an ingredient contained in exhaust gases emitted from an internal combustion engine, including a sensor for detecting the same concentration, wherein a correction value for the air-fuel ratio of a mixture being supplied to the engine is set in response to an output signal from the sensor, the correction value thus set being applied in detecting the abnormality. A first predetermined value and a second predetermined value smaller than the first predetermined value are set, which both lie within a first range defined by an upper limit value of the correction value and a lower limit value of same that can be assumed when the engine is in normal operating conditions.

Abstract: A fuel supply control system for an internal combustion engine, having fuel injection valves for supplying the engine with fuel having its pressure regulated to a predetermined value. A temperature sensor detects a temperature value representative of the temperature of fuel being supplied to the fuel injection valves. When the temperature value detected by the sensor is higher than a predetermined value at the start of the engine, an electronic control unit causes a solenoid-operated selector valve to operate to increase the pressure of fuel being supplied to the engine over a period of time dependent on the temperature value detected by the sensor from the time the engine is started.

Abstract: A method of controlling exhaust gas recirculation in an internal combustion engine, by means of an exhaust gas recirculation control system including an exhaust recirculating passage connected between the exhaust passage and the intake passage of the engine, an exhaust gas recirculating valve arranged across the exhaust gas recirculating passage, and differential pressure-operated actuator device for varying the opening of the exhaust gas recirculating valve. The differential pressure-operated actuator device has a pressure-responsive member displaceable in response to a pressure difference between atmospheric pressure applied to one side surface thereof and a synthetic pressure of pressure within the intake passage and atmospheric pressure, applied to the other side surface thereof. The differential pressure-operated actuator device is adapted to vary the synthetic pressure in response to at least one operating parameter of the engine to control the exhaust gas recirculating valve.

Abstract: Fuel injections are sequentially effected into cylinders of a multicylinder internal combustion engine in predetermined sequence in synchronism with pulses of a predetermined crank angle position signal from engine rotational angle sensing means. If no TDC signal pulse is generated between an immediately preceding pulse and a present pulse of a cylinder-discriminating signal, a simultaneous fuel injections are effected into all the engine cylinders upon generation of the present pulse of the cylinder-discriminating signal. Preferably, the engine rotational angle sensing means is determined to be abnormal when the simultaneous fuel injections have been effected consecutively a predetermined number of times.

Abstract: A control device for a hydraulic direct-coupling clutch of a hydraulic torque converter installed in an automotive vehicle, which is adapted to control the supply of operating fluid to the direct-coupling clutch by means of an electrically actuatable selector valve. Pilot fluid pressure generated by a pilot fluid pressure source acts upon one end face of a valve body of the selector valve to bias the valve body to a position for supplying the operating fluid to the direct-coupling clutch. A drain line communicates a pressure chamber of the selector valve defined by the one end face of the valve body with a zone under a low pressure, and an electromagnetic valve is arranged across the drain line, which is adapted to open the drain line when energized, to permit the pilot fluid pressure in the pressure chamber to escape to the zone under a lower pressure.