Abstract: A multi-cylinder internal combustion engine is provided with a group of constantly operated cylinders and a group of cylinders that can be switched off. An exhaust line having a catalytic converter is associated with each group of cylinders. A shutoff element is disposed downstream of the catalytic converter of the constantly operated cylinder subassembly. In addition, the two exhaust lines or the two catalytic converters are connected to each other via a bypass line. Maintaining the temperature of the second catalytic converter is made possible via the bypass line, even when the cylinders of the second group are not operated and when the exhaust line is closed.

Abstract: A engine exhaust system is disclosed for reducing the amount of hydrocarbons emitted during engine start-up (cold-start), before the catalytic converter has attained its effective operating temperature. The system includes a flow control device, in particular a bi-metallic flap, occupying a first position at the first temperature to direct substantially all of the engine exhaust through a molecular sieve structure to adsorb the hydrocarbons, and a second position at the second temperature, to direct the engine exhaust stream directly from the light-off catalyst to the burnoff catalyst, bypassing the molecular sieve structure.

Abstract: The double walled exhaust pipe of the present invention consists of an outer pipe which forms an outer wall of the exhaust pipe and an inner pipe which forms an inner wall of the exhaust pipe, the outer pipe and the inner pipe are fixed each other at an exhaust inlet portion which provides a reference point of the thermal expansion of the inner pipe and the outer pipe. The double walled exhaust pipe of the present invention has at least one bent portion. Further, the inner pipe of the double walled exhaust pipe is divided into longitudinal pipe sections, and at least one sliding connection, which connects the sections of the inner pipe permitting the relative longitudinal slide movements of the pipe sections, is provided between the exhaust inlet portion and the bent portion having the largest bending angle.

Abstract: An air-fuel ratio control apparatus for an engine for reliably converging an air-fuel ratio around a stoichiometric air-fuel ratio to prevent harmful exhaust components from being discharged into the air is described. The apparatus includes a CPU which determines an inversion direction of an output of an O.sub.2 sensor on the downstream side of a catalytic converter, corrects a target air-fuel ratio .lambda.TG in a step-like fashion in the opposite direction by a skip amount and calculates a fuel injection amount every injection timing on the basis of a difference between the corrected target air-fuel ratio .lambda.TG and an air-fuel ratio .lambda. detected by an O.sub.2 sensor on the upstream side of the exhaust flow. The target air-fuel ratio is reflected immediately in the fuel injection amount at an updating rate of every ilnjection timing, so that the fuel injection amount may be controlled with an excellent responsiveness to turbulence in the air-fuel ratio. Further, upper and lower limit guard values .

Abstract: An exhaust purification device which is capable of detecting the degree of deterioration of the NOx absorbent or the three-way catalyst arranged in the exhaust passage of an engine. An O.sub.2 sensor whose output current or output voltage is proportional to the air-fuel ratio is arranged inside the exhaust passage downstream of the NOx absorbent or three-way catalyst. The air-fuel ratio of the air-fuel mixture is temporarily changed from lean to rich or from rich to lean to enable the degree of deterioration of the NOx absorbent or three-way catalyst to be detected from the peak value of the output current or voltage of the O.sub.2 sensor during the time when the air-fuel ratio is changed.

Abstract: The pollution abatement incinerator system removes pollutants effectively, efficiently and economically from a flow of exhaust gases. The system will virtually eliminate compounds such as oxides of nitrogen, hydrocarbons, carbon monoxide, odors and organic and inorganic particulates from the exhaust gases of internal combustion engines or other sources of combustion. The resonant incinerator directly eliminates the undesirable and harmful pollution of the exhaust. A recuperator, preferably with two stages is incorporated into the system for efficiently capturing and reusing heat from the incinerator to simultaneously heat fresh air being forced through the recuperator and into the incinerator. A fuel converter is used to vaporize fuel of almost any type and inject the vaporized fuel into a ring injector within the incinerator. The ring injector disperses the vaporized fuel within incinerator. The vaporized fuel in the incinerator chamber is then ignited.

Abstract: A dual wall, air gap exhaust manifold with an integral inlet connecting flange defining an elongated, internal, air injection passageway enclosed by an L-shaped plate welded over an elongated slot in the flange to form the elongated passageway, the L-shaped plate also being welded over a series of short channels which extend between the elongated passageway and the manifold inlet openings. The elongated passageway has an air inlet connector. The spaced dual walls of the manifold runners are joined together at the flange openings, just downstream of the channels.

Abstract: A fuel delivery control apparatus for use with an internal combustion engine including an exhaust system having a catalytic converter containing catalysts operable at a temperature for purifying exhaust gases discharged through the exhaust system. A fuelcut control is performed to interrupt fuel delivery to the engine during engine deceleration. The fuelcut control is inhibited when the catalyst temperature exceeds a predetermined value.

Abstract: An air-fuel ratio control system for an internal combustion engine includes a pair of cylinder banks, a pair of exhaust passages connected to the cylinder banks, respectively, a common exhaust pipe where the exhaust passages join each other at their downstream ends, a pair of catalytic converters provided in the exhaust passages, respectively, a pair of main air-fuel ratio sensors provided in the exhaust passages upstream of the catalytic converters, respectively, a pair of auxiliary air-fuel ratio sensors provided in the exhaust passages downstream of the catalytic converters, respectively, and a catalytic converter provided in the common exhaust pipe. The system derives an air-fuel ratio feedback control correction value for each of the cylinder banks based on outputs of the auxiliary air-fuel ratio sensors.

Abstract: In an internal combustion engine with oxygen sensors provided respectively upstream and downstream of an exhaust purification catalytic converter, the air-fuel ratio is feedback controlled based on an output of the second oxygen sensor only. When in this control situation, an output period of the first oxygen sensor becomes longer than that of the second oxygen sensor, response deterioration of the first oxygen sensor is judged to have occurred. Once the occurrence of response deterioration is determined, a proportional operating amount used in a proportional control of an air-fuel ratio feedback correction coefficient LMD for air-fuel ratio feedback control using the first oxygen sensor, is corrected in proportion to the response deterioration to thereby correct a deviation of the air-fuel ratio control point.

Abstract: To provide an exhaust pipe structure capable of arranging a plurality of exhaust pipes in a restricted space inside a cover and suppressing the discoloring of the cover due to an increase in the temperature of the cover. Each of a plurality of exhaust pipes introduced from each cylinder of a multi-cylinder engine includes a double-pipe structure of an outer pipe and an inner pipe. The exhaust pipes pass inside the cover in such a manner that at least one exhaust pipe near the inner side surface of the cover is left as being of the double-pipe structure, and at least each of the remaining exhaust pipes has a portion of a single-pipe structure.

Abstract: The present invention is a method for obtaining an inferred soak time suitable for inferring exhaust system and other temperatures with sufficient accuracy to permit control of at least one feature of an internal combustion engine to be based thereon. In this way, soak time strategy can be inexpensively incorporated into an engine control system not based on soak time or soak timer hardware can be replaced in control systems with soak time strategy. The temperature of the engine and of the charging air supplied to the engine are measured at the time the engine is turned off and when the engine is restarted. The measured temperature of the engine and of the charging air at the time the engine is turned off is stored in a computer memory. The inferred soak time is obtained using the measured temperature of the engine and of the charging air stored at the time the engine is turned off and measured at the time the engine is restarted.

Abstract: An exhaust manifold joint includes a number of like exhaust manifold segments mounted to a corresponding number of cylinder heads of a large diesel engine. The exhaust manifold segments slip relative one another to accommodate thermal growth differentials between the exhaust manifold segments and the cylinder head. The exhaust manifold segments are further mounted to the cylinder head via fasteners that extend through a bolt hole of the exhaust. manifold. The bolt hole incorporates a reverse counterbore at the manifold to cylinder head attachment to move loading of the fastener away from the attachment, thereby resulting in elastic deformation rather than yielding of the fastener during loading of the fastener.

Abstract: In an apparatus for controlling the introduction of air into an exhaust pipe of an internal combustion engine in which air is introduced from the intake side to the exhaust side to improve the efficiency of purifying exhaust gases, to prevent a decline in the purification efficiency of a catalyst in a state in which the exhaust gas temperature immediately after starting is low. A control valve 11 is provided in an air introducing pipe 9 for introducing air from the intake side to the exhaust side, and the control valve 11 is set in a shut-off state during starting or during starting and a predetermined time duration immediately after starting.

Abstract: An exhaust gas-treating process by capturing particulates in exhaust gas discharged from an internal combustion engine with use of a honeycomb structural filter, the process including the steps of: (1) capturing the particulates contained in the exhaust gas by passing the exhaust gas through the filter; (2) stopping flow of the exhaust gas through the filter and transferring the captured particulates to a location remote from and outside an exhaust line by flowing the particulates captured by the filter in a direction reverse to a flowing direction of the exhaust gas; and (3) burning the particulates and discharging a burnt matter outside. The filter preferably has a honeycomb structural body and second sealed portions in first and second rows at opposite ends of the honeycomb structural body, respectively.

Abstract: In an exhaust emission control system in an internal combustion engine which includes a spark plug disposed to face a combustion chamber, an intake system having a fuel injection valve disposed therein, an exhaust system having a catalytic converter incorporated therein and filled with a catalyst for reducing nitrogen oxide (NO.sub.x) in the presence of hydrocarbons in an oxidizing atmosphere, and an exhaust gas circulation amount control means capable of measuring and controlling the amount of exhaust gas circulated from the exhaust system to the intake system. The amount of exhaust gas circulated by the exhaust gas circulation amount control means the amount and timing of fuel injected by the fuel injection valve and the timing of ignition of the spark plug are controlled by a control unit, so that the amount of NO.sub.x discharged, is detected by the NO.sub.x detector in the exhaust system at a location downstream from the catalytic converter, is equal to or less than an acceptable amount of NO.sub.

Abstract: A malfunction monitoring apparatus for a secondary air supply system of an internal combustion engine includes an air flow sensor for measuring the flow rate of an air flowing into an intake air path of the engine, a secondary air introducing path disposed in the intake air path on the downstream side of a measuring position of the air flow rate for taking in a part of the air through the intake air path as a secondary air, a secondary air supply device for supplying the secondary air to an exhaust gas path, and a control unit. The apparatus may further include a pressure sensor for detecting the internal pressure of an intake manifold.

Abstract: A catalytic converter has a carrier structure and a catalytically active coating adhering to the carrier structure, and is disposed downstream of an internal combustion engine of a motor vehicle for cleaning exhaust gas. A method for functional monitoring of the catalytic converter includes determining a temperature of the catalytically active coating and/or of the structure of the catalytic converter at least at one location. A temperature of the exhaust gas is determined upstream of the at least one location of the catalytic converter. At least first derivatives over time of both temperature values are formed. A difference of the derivatives over time is formed. An instant after a start of the engine at which the difference changes its sign is ascertained. An apparatus for functional monitoring of the catalytic converter includes at least one measuring sensor for measuring a temperature of the carrier structure and/or of the catalytically active coating.

Abstract: Exhaust gas cleaner system for an automotive internal combustion engine includes an air introduction pipe 8 for introducing secondary air, heated initially by a heater 23, to the catalytic converter unit 7 mounted on the exhaust pipe 3. The ignition timings of the engine is retarded at least during the time when the secondary air is heated by the heater 23. Preferably, the number of ignition timings are counted by a counter modulo 5, for example, in the case of a four-cylinder engine, and the ignition timings are retarded when the counter content is 3 or 4, such that the ignition timings of the cylinders are retarded intermittently. Alternatively, the retardation of the ignition timings may be terminated before the introduction of the heated secondary air is terminated.Where two first and second catalytic converter units 7a and 7b are provided, secondary air distributed by a change-over valve 10a is heated separately by heaters 23b and 23c.

Abstract: A system for purifying an exhaust gas for use in an automobile is disclosed which does not externally discharge unburnt hydrocarbons until a catalyst becomes active. An adsorbent is provided upstream of the catalyst. A heat exchanger is disposed between an upstream portion of the adsorbent and a portion between the adsorbent and the catalyst for controlling the elevation of the temperature of the adsorbent and for promoting the elevation of the temperature of the catalyst. The unburnt hydrocarbons are absorbed by the adsorbent in the initial period of time from starting of an engine until the catalyst becomes active. Temperature control is made in such a manner that the unburnt hydrocarbons which are adsorbed by the adsorbent begins to be desorbed therefrom substantially simultaneously with the time when the catalyst begins to function.