Abstract: In order to prevent a catalyst for an internal combustion engine from decreasing efficiency by deterioration after long time use of the catalyst, the decreased efficiency of the catalyst is determined, and the internal engine is controlled based on results of the determination so as to maintain high efficiency of the catalyst. The catalyst is installed in an exhaust pipe of the engine. Sensors for detecting conditions of exhaust gas both at upstream side and downstream side of the catalyst are provided, respectively. As for the sensor, for example, an oxygen sensor of which output varies stepwise at ?=1, or a sensor of which output varies in proportion to air-fuel ratio can be used. Detected values of the sensors are taken into a control unit, eliminating efficiency and deteriorating degree of the catalyst are estimated by comparison of the detected values, and the engine is controlled so that the eliminating efficiency becomes maximum.

Abstract: In order to prevent a catalyst for an internal combustion engine from decreasing efficiency by deterioration after long time use of the catalyst, the decreased efficiency of the catalyst is determined, and the internal engine is controlled based on results of the determination so as to maintain high efficiency of the catalyst. The catalyst is installed in an exhaust pipe of the engine. Sensors for detecting conditions of exhaust gas both at upstream side and downstream side of the catalyst are provided, respectively. As for the sensor, for example, an oxygen sensor of which output varies stepwise at &lgr;=1, or a sensor of which output varies in proportion to air-fuel ratio can be used. Detected values of the sensors are taken into a control unit, eliminating efficiency and deteriorating degree of the catalyst are estimated by comparison of the detected values, and the engine is controlled so that the eliminating efficiency becomes maximum.

Abstract: In order to prevent a catalyst for an internal combustion engine from decreasing efficiency by deterioration after long time use of the catalyst, the decreased efficiency of the catalyst is determined, and the internal engine is controlled based on results of the determination so as to maintain high efficiency of the catalyst. The catalyst is installed in an exhaust pipe of the engine. Sensors for detecting conditions of exhaust gas both at upstream side and downstream side of the catalyst are provided, respectively. As for the sensor, for example, an oxygen sensor of which output varies stepwise at &lgr;=1, or a sensor of which output varies in proportion to air-fuel ratio can be used. Detected values of the sensors are taken into a control unit, eliminating efficiency and deteriorating degree of the catalyst are estimated by comparison of the detected values, and the engine is controlled so that the eliminating efficiency becomes maximum.

Abstract: A combustion state is diagnoses by extracting specific rotation period component of a period synchronous with rotation from a combustion state parameter for at least two rotations. The combustion state is judged on the basis of the extracted specific rotation period component. The combustion state parameter may be the engine speed or the output torque of a multiple-cylinder engine which varies according to the combustion state of the engine.

Abstract: The object of this invention is that a suction device for an internal combustion engine is to be compact. The suction device comprising a casing having an air inlet and a plurality of outlets, a filter in the casing for filtering air from said air inlet, a collection chamber in the casing for receiving air from the filter, at least one throttle valve in the casing for controlling the flow of air from said filter to said collection chamber, and a plurality of suction pipes. According to the present invention, the suction device can be made compact to thereby effectively use an engine room of an automobile.

Abstract: The object of this invention is that a suction device for an internal combustion engine is to be compact. The suction device comprising a casing having an air inlet and a plurality of outlets, a filter in the casing for filtering air from said air inlet, a collection chamber in the casing for receiving air from the filter, at least one throttle valve in the casing for controlling the flow of air from said filter to said collection chamber, and a plurality of suction pipes. According to the present invention, the suction device can be made compact to thereby effectively use an engine room of an automobile.

Abstract: A one-piece suction device is provided for an internal combustion engine including a collector into which air flows through an electronically controlled throttle valve driven by an electric motor and individual suction pipes for distributing the air to respective cylinders of the internal combustion engine from the collector. A first bent-form air flow passage is formed which extend from an air intake inlet port of the suction device to an inlet port of the throttle valve and from an outlet port of the throttle valve to the collector. A second bent-form air flow passage is formed between an inlet port of the collector and an outlet port of one of the individual suction pipes. The air flow amount flowing through said first and second bent-form air flow passages is adjusted by said electronically controlled throttle valve.

Abstract: The object of this invention is that a suction device for an internal combustion engine is to be compact. The suction device comprising a casing having an air inlet and a plurality of outlets, a filter in the casing for filtering air from said air inlet, a collection chamber in the casing for receiving air from the filter, at least one throttle valve in the casing for controlling the flow of air from said filter to said collection chamber, and a plurality of suction pipes. According to the present invention, the suction device can be made compact to thereby effectively use an engine room of an automobile.

Abstract: A diagnosis apparatus for diagnosing a catalytic converter of a motor vehicle as to whether the catalyst suffers deterioration by estimating a temperature of the catalyst or that of the exhaust gas in the vicinity of the catalyst on the basis of a plurality of engine parameters to thereby decide deterioration of the catalyst by using as an index the estimated temperature. Diagnosing method and apparatus capable of diagnosing deterioration of the catalyst with a high reliability are realized.

Abstract: The object of this invention is that a suction device for an internal combustion engine is to be compact. The suction device comprising a casing having an air inlet and a plurality of outlets, a filter in the casing for filtering air from said air inlet, a collection chamber in the casing for receiving air from the filter, at least one throttle valve in the casing for controlling the flow of air from said filter to said collection chamber, and a plurality of suction pipes. According to the present invention, the suction device can be made compact to thereby effectively use an engine room of an automobile.

Abstract: A combustion control device for an internal combustion engine, establishes an optimum combustion condition by detecting the combustion pressure in the cylinder and controlling the exhaust gas reflux rate, the ignition timing and the fuel injection timing or the injection rate at the intake stroke in order to improve the fuel economy and the quality of the exhaust gas in the engine. The device is provided with an in-cylinder pressure detector for detecting the in-cylinder pressure in connection with the combustion in the engine, and apparatus for estimating the heat generation rate with respect to the angle of the crank shaft of the cylinder according to the output from the in-cylinder pressure detection means, the ignition timing and the fuel injection timing control the control variables such as EGR control parameters related to the combustion so that the in-cylinder combustion state pattern obtained by the heat generation rate estimation apparatus may be reshaped into a predefined waveform pattern.

Abstract: In order to prevent a catalyst for an internal combustion engine from decreasing efficiency by deterioration after long time use of the catalyst, the decreased efficiency of the catalyst is determined, and the internal engine is controlled based on results of the determination so as to maintain high efficiency of the catalyst. The catalyst is installed in an exhaust pipe of the engine. Sensors for detecting conditions of exhaust gas both at upstream side and downstream side of the catalyst are provided, respectively. As for the sensor, for example, an oxygen sensor of which output varies stepwise at &lgr;=1, or a sensor of which output varies in proportion to air-fuel ratio can be used. Detected values of the sensors are taken into a control unit, eliminating efficiency and deteriorating degree of the catalyst are estimated by comparison of the detected values, and the engine is controlled so that the eliminating efficiency becomes maximum.

Abstract: It is an object of the present invention to provide a low-cost combustion state diagnosing system and a combustion state diagnosing method capable of accurately detecting misfires which occur at a low frequency while a multiple-cylinder engine is operating at a high engine speed under a low load.

Abstract: The object of this invention is that a suction device for an internal combustion engine is to be compact. The suction device comprising a casing having an air inlet and a plurality of outlets, a filter in the casing for filtering air from said air inlet, a collection chamber in the casing for receiving air from the filter, at least one throttle valve in the casing for controlling the flow of air from said filter to said collection chamber, and a plurality of suction pipes. According to the present invention, the suction device can be made compact to thereby effectively use an engine room of an automobile.

Abstract: It is an object of the present invention to provide a low-cost combustion state diagnosing system and a combustion state diagnosing method capable of accurately detecting misfires which occur at a low frequency while a multiple-cylinder engine is operating at a high engine speed under a low load.

Abstract: There is disclosed a leakage diagnosis of an evaporative system in an internal combustion engine, and more particularly there is disclosed an evaporative system in which a more accurate leakage diagnosis can be effected using a change in the pressure in the evaporative system, and such a diagnosis method is also disclosed. The evaporative system includes a gauge line having a gauge valve, which gauge line branches off from an evaporative gas line or an evaporative gas purge line, and communicates with a point upstream of an engine throttle valve or with the ambient atmosphere, a pressure sensor for detecting the pressure in the evaporative system, and a purge valve. A leakage diagnosis of this system is effected based on detected values of the pressure sensor obtained by opening and closing the purge valve and the gauge valve. Therefore, accurate results of the diagnosis can be obtained.

Abstract: In order to prevent a catalyst for an internal combustion engine from decreasing efficiency by deterioration after long time use of the catalyst, the decreased efficiency of the catalyst is determined, and the internal engine is controlled based on results of the determination so as to maintain high efficiency of the catalyst. The catalyst is installed in an exhaust pipe of the engine. Sensors for detecting conditions of exhaust gas both at upstream side and downstream side of the catalyst are provided, respectively. As for the sensor, for example, an oxygen sensor of which output varies stepwise at &lgr;=1, or a sensor of which output varies in proportion to air-fuel ratio can be used. Detected values of the sensors are taken into a control unit, eliminating efficiency and deteriorating degree of the catalyst are estimated by comparison of the detected values, and the engine is controlled so that the eliminating efficiency becomes maximum.

Abstract: An air intake arrangement for an internal combustion engine comprising: a main air intake conduit leading to a gas intake valve (241) for respective engine cylinders (206) and including a main air intake passage (202), a main collector chamber (204) and independent branching air intake passages (205) for the respective engine cylinders (206) connected in series; a throttle valve (203) disposed in the main intake air passage (202) for controlling the flow rate of air passing therethrough; an auxiliary air intake passage (210) bypassing the main air intake conduit, wherein an inlet port of the auxiliary air intake passage (210) opens into the main air intake passage (202) at the upstream of the throttle valve (203), and an outlet port (213) of the auxiliary air intake passage (210) opens into the respective independent branching air intake passage (205) near the gas intake valve (241) for the respective engine cylinders (206) in such a manner that gas blown-out from the auxiliary air intake passage (210) induc

Abstract: An automatic transmission control system for an automobile, comprising a vehicle weight estimation unit which estimates a vehicle weight of the automobile a torque estimation unit which estimates an output torque, an acceleration input unit which accepts an acceleration signal; a load estimation unit (110) which estimates a running load from the estimated vehicle weight, the estimated output torque and the accepted acceleration; a memory which stores a plurality of shift schedules therein; and a gear position determination unit (109) which includes the memory, and which selects one of the shift schedules in accordance with the vehicle weight and the estimated running load, so as to determine a gear position of an automatic transmission of the automobile in conformity with the selected shift schedule. An exact shift operation conformed to the vehicle weight and the running load can be performed, and an enhanced fuel consumption can be attained.

Abstract: An automatic transmission control system for an automobile, comprising a vehicle weight estimation unit which estimates a vehicle weight of the automobile a torque estimation unit which estimates an output torque, an acceleration input unit which accepts an acceleration signal; a load estimation unit (110) which estimates a running load from the estimated vehicle weight, the estimated output torque and the accepted acceleration; a memory which stores a plurality of shift schedules therein; and a gear position determination unit (109) which includes the memory, and which selects one of the shift schedules in accordance with the vehicle weight and the estimated running load, so as to determine a gear position of an automatic transmission of the automobile in conformity with the selected shift schedule. An exact shift operation conformed to the vehicle weight and the running load can be performed, and an enhanced fuel consumption can be attained.