Abstract: The invention relates to an exhaust gas purifier and a catalytic method of purifying exhaust gas, in which exhaust gas led into a combustion chamber (5) of the exhaust gas purifier, the exhaust gas is brought to centrifugal rotational motion, by which the exhaust gas flow is divided into a particle flow (9) and an actual gas flow (10). The particle flow (9) separated from the actual gas flow is retarded in relation to the actual gas flow (10). The direction of propagation of the particle flow is turned to be essentially opposite and the particle flow is rejoined to the actual gas flow and the rejoined exhaust gas flow is directed through a catalyst element (6).

Abstract: This invention is concerned with a fuel-vapor treatment method and apparatus for an internal combustion engine that do not introduce perturbations in the air/fuel ratio during purge-on or purge-off operations. According to the method and apparatus disclosed herein, a sensor output voltage .alpha. (for example, 4.5 V) is set that indicates a catalyst atmosphere neither rich nor lean, or in other words, at stoichiometry. When the present output voltage of a sub O.sub.2 sensor is greater than .alpha., indicating a rich atmosphere, a purge-off operation which entails enrichment is prohibited and a purge-on operation which entails making the atmosphere lean is allowed. Conversely, when the present output voltage of the sub O.sub.2 sensor is not greater than .alpha., indicating a lean atmosphere, a purge-on operation which entails making the atmosphere lean is prohibited and a purge-off operation which entails enrichment is allowed.

Abstract: An exhaust system for an internal combustion engine having an exhaust port and an exhaust chamber communicating between the ports includes a variable dimension element in the exhaust chamber adapted to vary an effective dimension of the exhaust chamber during operation of the engine.

Abstract: An air-fuel ratio control system for an internal combustion engine has a catalytic converter arranged in an exhaust passage. A maximum oxygen storage amount indicative of the maximum amount of oxygen that can be stored in the catalytic converter is calculated. The air-fuel ratio of a mixture supplied to the engine is forcibly oscillated at a predetermined frequency and a predetermined amplitude. At least one of the predetermined frequency and the predetermined amplitude is changed at a predetermined rate of change. A predetermined rate of change of the at least one of the predetermined frequency and the predetermined amplitude is set in dependence on the maximum oxygen storage amount to thereby secure the maximum purification rate of the catalytic converter.

Abstract: An adsorption apparatus provided with a means for physically separating and removing moisture, such as a cyclone type separating means or metal honeycomb or other cooling and condensing means, at the upstream side of a hydrocarbon adsorbent so as to enable the hydrocarbons exhausted at the time of engine start-up to be efficiently adsorbed by eliminating the decline in the adsorption power caused by the moisture in the exhaust gas.

Abstract: A secondary air control apparatus constituted by an exhaust gas purifier 32 of an engine 21, a feed quantity control valve 29 for feeding secondary air, a secondary air heating device 31, and a controller 35 for controlling the feed quantity of secondary air and the secondary air heating device 31. The quantity of secondary air to be fed is set in accordance with the operation conditions of an engine, and the secondary air to be fed is modulated in quantity and heated, so that it is possible to utilize the purifying effect of a catalyst efficiently.

Abstract: The invention is directed to a method for evaluating the operability of a catalytic converter operated in the exhaust-gas channel of an internal combustion engine. The invention utilizes the recognition that the conversion-begin temperature of the catalytic converter is that much higher the more the catalytic converter has deteriorated. In improved embodiments, the realization is utilized that the more a catalytic converter has deteriorated, the less heat is converted by combusting oxidizable exhaust gas components per unit of time. In a first embodiment of the method, a check is made as to when a catalytic converter starts converting and then evaluating the converter as being operable when the determined temperature is less than a comparison temperature. A second embodiment provides that the catalytic converter is operated at precisely pregiven operating conditions and a check is made as to how long is required until the converter begins to convert.

Abstract: A method is provided for checking the efficiency of a catalytic converter with an oxygen probe upstream of the catalytic converter and of an oxygen probe downstream of the catalytic converter. A ratio of times in which the oxygen probe downstream of the catalytic converter and the oxygen probe upstream of the catalytic converter indicate a rich or a lean mixture value is formed. The catalytic converter has a sufficient efficiency if the value of the smaller amount of the ratio values is lower than a predeterminable limit value.

Abstract: A method and device for monitoring a heating device of a sensor mounted in the exhaust system of an internal combustion engine. In assessing the working order of the heating device, use is made of the fact that a sensor heated by a heating element heats up more strongly than an unheated sensor, and that it is possible to establish, with the aid of the signals output by the sensor, whether the sensor has exceeded its minimum operating temperature. The temperature of the sensor is simulated as a function of internal combustion engine operating characteristics. The working order of the heating device can be assessed with the aid of the simulated temperature and the information as to whether the minimum operating temperature is exceeded.

Abstract: A secondary air supplying apparatus for an internal combustion engine and a gas heating apparatus are provided to enable high-performance exhaust gas purification in a catalytic apparatus of the internal combustion engine, in particular, even at a low-temperature starting time. A secondary air supplying apparatus supplies secondary air to the catalytic apparatus through a secondary air introducing path for communicating the intake side of the internal combustion engine with an exhaust manifold. In the apparatus, a gas heating apparatus having an exothermic body is provided for the secondary air introducing path.

Abstract: An emission control system for internal-combustion engines has a purifying insert which is arranged in a housing by way of an intermediate layer and whose inflow-side front side is subjected to a diagonal flow by way of an inflow pipe, to achieve a simple connection of the inflow pipe and the housing, the inflow pipe has a section which represents a boundary around the insert downstream of its front side and is used as a connection with the housing.

Abstract: A soot filtration device (1) in the exhaust gas section of a diesel internal-combustion engine comprises a housing with an exhaust gas inlet (2) and an outlet (3) for the filtered exhaust gas, a plurality of soot filter cartridges (4) arranged in the housing, and at least one regeneration apparatus (5). The soot filter cartridges (4) are arranged in at least two separate chambers (6), and each of these chambers (6) has a closable inlet opening (7).

Abstract: A gasketless connector for connecting a first tubular member having a flared end portion to a second tubular member. The connector member is provided with a substantially domical body portion having inner and outer surfaces and first and second side portions, a first tubular portion extending in a first direction from the first side of the domical portion and a second tubular portion extending in a second direction from the second side of the substantially domical portion. The first tubular portion is disposed for extending into the first tubular member for abutting relation of the flared surface of the first tubular member with the outer surface of the first side of the domical portion. The second tubular portion is disposed for secured relation with the second tubular member.

Abstract: An air-fuel ratio control system for an internal combustion engine having a catalytic converter arranged in the exhaust system, has an upstream oxygen sensor and a downstream oxygen sensor arranged in the exhaust system at locations upstream and downstream of the catalytic converter, respectively. An ECU determines a feedback control constant, based on an output from the downstream oxygen sensor, and determines an air-fuel ratio control amount, based on the determined feedback control constant and an output from the upstream oxygen sensor. The ECU carries out feedback-control of the air-fuel ratio of a mixture supplied to the engine by means of the determined air-fuel ratio control amount. The updating rate of the feedback control constant is set based on the temperature of the catalyst of the catalytic converter.

Abstract: A motorcycle having a secondary air supply for delivering air to the exhaust ports of the engine for assisting in exhaust treatment of the exhaust gases. Air is supplied through reed-type check valves which are positioned in a concealed portion of the motorcycle body for silencing noise. The conduit which connects the check valves to the exhaust ports extends vertically downwardly substantially throughout its length so that condensed liquids in the conduit will pass back to the exhaust port rather than accumulate in the conduit.

Abstract: The present invention is directed to an in-line engine exhaust system. In general, the exhaust system is comprised of the following: (1) a honeycomb structure having an inlet and outlet end disposed in a housing and located in an exhaust gas stream downstream from an engine and possessing a first substantially unobstructed flow region, a second more obstructed flow region adjacent the first region; and, (2) a fluidics apparatus disposed in the exhaust stream proximate to the first region for creating a negative flow zone within the first region, which in turn results in diverting a portion of the exhaust gases away from the first region. More specifically, the fluidics apparatus includes a source diversion fluid, typically air, a conduit for delivering the diversion fluid and a diverter body for diverting the diversion fluid.

Abstract: There is disclosed a diesel particulate filter for filtering exhaust gasses of a diesel engine while collecting particulates and burning them by electric heat. The diesel particulate filter includes at least one filter body disposed in a filter case with filtering passages characterized as coarseness or mesh which gradually changes density of the exhaust flow as it moves from an upstream side toward a downstream side.

Abstract: A control system (14) is described for an internal combustion engine having a catalytic converter and a heater (12) for raising the temperature of the catalyst in the catalytic converter. The control system comprising an electrical circuit (16) for estimating, rather than measuring, the temperature of the catalyst and means for controlling the heater (12) of the catalytic converter based on the estimated catalyst temperature.

Abstract: Selectively operable first and second exhaust valves are provided for every combustion chamber in an engine. Branch pipes of a first intake manifold are connected to first exhaust ports opened and closed by the first exhaust valves, and branch pipes of a second exhaust manifold are connected to second exhaust ports opened and closed by the second exhaust valves. An adsorbing trap is provided in an aggregated pipe of the first exhaust manifold and a catalytic converter is provided in a common exhaust pipe connected to the aggregated pipes of the first and second exhaust manifolds. Only the first exhaust valves are operated to open and close at a low temperature of the adsorbing trap to permit the exhaust gas to flow into the first exhaust manifold. Thus, hydrocarbons (HCs) in the exhaust gas are adsorbed into the adsorbing trap at the low temperature and the heat of the exhaust gas is effectively utilized to promote the activation of the catalytic converter.

Abstract: An inlet or exhaust line for a reciprocating machine attenuates the sound level of the machine while being simple and economical to produce. A sensor measures the instantaneous flow rate of gases passing through the line while a restriction device variably restricts the cross-section of the line as a function of the instantaneous flow rate measured by the sensor. Material for absorbing acoustic energy covers the internal wall of the line.