Abstract: An exhaust gas purification device including three-way catalysts connected to engine cylinder groups and arranged in parallel, and a NOx trapping catalyst connected with the three-way catalysts downstream thereof. A controller controls fuel injection for making an A/F ratio of exhaust gas flowing into one of the three-way catalysts rich relative to a stoichiometric A/F ratio when it is required to reduce the NOx trapped by the NOx trapping catalyst.

Abstract: An exhaust gas purifying system for a cylinder direct internal combustion engine having a fuel injector valve for directly injecting fuel into a combustion chamber of the engine. The exhaust gas purifying system comprises an adsorbent catalytic converter disposed in an exhaust gas passageway of the engine. The adsorbent catalytic converter including a catalytic element having an adsorption layer. The adsorption layer contains an adsorbent for adsorbing HC (hydrocarbons) of exhaust gas in a first temperature range and to release the adsorbed HC in a second temperature range which is high relative to the first temperature range, and a catalyst component for promoting reaction for oxidizing HC which is released from the adsorbent.

Abstract: An upstream catalyst (12) which stores oxygen in exhaust gas and releases the stored oxygen for oxidizing a reducing agent component contained in the exhaust gas, and a downstream catalyst (13) which stores nitrogen oxides in the exhaust gas and releases the stored nitrogen oxides by reducing the stored nitrogen oxides by the reducing agent component contained in the exhaust gas, are provided in an exhaust passage (11) of an engine (2). When the storage amount of nitrogen oxides of the downstream catalyst (13) reaches a predetermined value, additional fuel is injected from a fuel injector (7) after combustion, and stored oxygen in the upstream catalyst (12) is released by the reducing agent components in the additional fuel. After release of oxygen, the supply of the additional fuel is stopped and the supply of the main fuel is increased.

Abstract: An exhaust gas purification apparatus and method is applied to an internal combustion engine. The internal combustion engine generates an exhaust gas to be introduced to an exhaust system thereof. There is provided a reformer and controller. The reformer introduces a fuel and a part of the exhaust gas and generates a reformed gas including at least hydrogen and the controller is programmed to control a fuel supply amount of the fuel introduced to the reformer and an exhaust gas introduction amount of the exhaust gas introduced to the reformer in accordance with a demanded hydrogen amount of the reformer and operating conditions of the internal combustion engine. The exhaust gas is purified while controlling the fuel supply amount and the exhaust gas introduction amount.

Abstract: In an exhaust path, a HC trapping material which traps HC contained in exhaust gas temporarily, a H2O trap which traps H2O contained in exhaust gas and a CO oxidation catalyst are arranged in this order from the upstream side, wherein the H2O trap is disposed just upstream of and close to the CO oxidation catalyst. H2O and HC which are components disturbing the activity of the CO oxidation catalyst can be removed efficiently and the adsorption heat and condensation heat of H2O can be efficiently utilized to raise the temperature of the CO oxidation catalyst so that early activation of the CO oxidation catalyst is accomplished just after an engine starts.

Abstract: In an automotive vehicle with at least one catalyst located in an exhaust passage for adsorbing oxygen contained within exhaust gases entering the catalyst, and an air/fuel ratio sensor located in the exhaust passage upstream of the catalyst for detecting an air/fuel ratio based on a percentage of oxygen contained within the exhaust gases flowing through the exhaust passage and entering the catalyst, an air/fuel ratio control system controls an air/fuel mixture ratio of the engine at as close to stoichiometric as possible, an air/fuel ratio control system calculates a quantity of oxygen stored in the catalyst on the basis of a deviation of the air/fuel ratio detected by the air/fuel ratio sensor from a stoichiometric air/fuel ratio to produce informational data indicative of a calculated value of the quantity of oxygen stored. The control system controls the air/fuel mixture ratio of the engine so that the calculated value of the quantity of oxygen stored is adjusted to a desired value.

Abstract: The invention relates to a zoom lens system of three-group construction, one lens for each group, which is less susceptible to aberration variations even upon zooming and can achieve entire-length reductions, large lens aperture and high zoom ratio. The zoom lens system comprises, in order from an object side thereof, a first lens group G1 consisting of one single lens formed of a homogeneous medium and having positive refracting power, a second lens group G2 consisting of one single lens formed of a homogeneous medium and having negative refracting power, and a third lens group G3 consisting of one single lens formed of a homogeneous medium and having positive refracting power. For zooming from a wide-angle end to a telephoto end of the zoom lens system, at least the second lens group G2 moves from the object side toward an image side of the zoom lens system.

Abstract: The invention relates to a zoom lens system of two-group construction, one lens for each group, which is less susceptible to aberration variations even upon zooming and can be much more increased in terms of lens aperture and zoom ratio. The zoom lens system of two-group construction comprises, in order from an object side thereof, a first lens group G1 having negative refracting power and a second lens group G2 having positive refracting power and in which a focal length thereof is varied by moving both the lenses while an optical axis separation therebetween is varied. The first lens group G1 consists of one concave lens having a strong concave surface directed toward an image plane side of the zoom lens system and formed of a homogeneous medium, and the second lens group G2 consists of one convex lens formed of a homogeneous medium. A stop S is located between the first lens group G1 and the second lens group G2.

Abstract: In an automotive vehicle with at least one catalyst located in an exhaust passage for adsorbing oxygen contained within exhaust gases entering the catalyst, and an air/fuel ratio sensor located in the exhaust passage upstream of the catalyst for detecting an air/fuel ratio based on a percentage of oxygen contained within the exhaust gases flowing through the exhaust passage and entering the catalyst, an air/fuel ratio control system controls an air/fuel mixture ratio of the engine at as close to stoichiometric as possible, an air/fuel ratio control system calculates a quantity of oxygen stored in the catalyst on the basis of a deviation of the air/fuel ratio detected by the air/fuel ratio sensor from a stoichiometric air/fuel ratio to produce informational data indicative of a calculated value of the quantity of oxygen stored. The control system controls the air/fuel mixture ratio of the engine so that the calculated value of the quantity of oxygen stored is adjusted to a desired value.

Abstract: An upstream catalyst (11) which stores oxygen in exhaust gas and releases the stored oxygen for oxidizing a reducing agent component contained in the exhaust gas, and a downstream catalyst (13) which stores nitrogen oxides in the exhaust gas and releases the stored nitrogen oxides by reducing the stored nitrogen oxides by the reducing agent component contained in the exhaust gas, are provided in an exhaust passage (11) of an engine (2). When the storage amount of nitrogen oxides of the downstream catalyst (13) increases, additional fuel is injected from a fuel injector (7) after combustion, and stored oxygen in the upstream catalyst (12) is released by the reducing agent components in the additional fuel. After release of oxygen, the supply of the additional fuel is stopped and the supply of the main fuel is increased.

Abstract: A set of lens systems consisting of a plurality of different kinds of lens systems each comprising a radial type gradient index lens element(s), wherein the radial type gradient index lens elements have a common refractive index distribution.

Abstract: An air-fuel ratio controller for an internal combustion engine with a catalytic converter in an exhaust passage has an air-fuel ratio sensor, an engine sensor, and a control unit. The air-fuel ratio sensor produces a signal indicative of an air-fuel ratio of an exhaust gas in the exhaust passage on an upstream side of the catalytic converter. The engine sensor produces a signal indicative of misfiring of the engine. The control unit is operatively coupled to the air-fuel ratio sensor and the engine sensor. The control unit computes an estimated quantity of oxygen to be stored in the catalytic converter based on the signal from the air-fuel ratio sensor, and determines if the engine is misfiring based on the signal from the engine sensor.

Abstract: A catalyst in an exhaust passage for an engine is capable of storing oxygen. A memory stores, as an oxygen storage capacity, an oxygen storage amount at the time of change of the downstream air-fuel ratio on the downstream side of the catalyst from stoichiometric to lean. A processor calculates the current oxygen storage amount accurately in due consideration of a fast oxygen absorbing rate in the case of the downstream air-fuel ratio being stoichiometric, and a slow oxygen absorbing rate in the case of the downstream air-fuel ratio being lean, and controls the air-fuel ratio of the exhaust gas mixture flowing into the catalyst so as to bring the oxygen storage amount in a region under the oxygen storage capacity.

Abstract: In an automotive vehicle with at least one catalyst located in an exhaust passage for adsorbing oxygen contained within exhaust gases entering the catalyst, and an air/fuel ratio sensor located in the exhaust passage upstream of the catalyst for detecting an air/fuel ratio based on a percentage of oxygen contained within the exhaust gases flowing through the exhaust passage and entering the catalyst, an air/fuel ratio control system controls an air/fuel mixture ratio of the engine at as close to stoichiometric as possible, an air/fuel ratio control system calculates a quantity of oxygen stored in the catalyst on the basis of a deviation of the air/fuel ratio detected by the air/fuel ratio sensor from a stoichiometric air/fuel ratio to produce informational data indicative of a calculated value of the quantity of oxygen stored. The control system controls the air/fuel mixture ratio of the engine so that the calculated value of the quantity of oxygen stored is adjusted to a desired value.

Abstract: An exhaust emission control system for an internal combustion engine is provided. The exhaust emission control system comprises a catalytic converter disposed in an exhaust passage of the engine, a wide-range A/F ratio sensor disposed in the exhaust passage at a location downstream of the catalytic converter for detecting an A/F ratio of a mixture supplied to the engine, and a control unit including a detecting section for detecting the degree of water gas reaction caused in the catalytic converter and a correcting section for correcting a detected value of the A/F ratio on the basis of the degree of water gas reaction.

Abstract: A lens system comprising, in order from the object side, a first lens unit having a positive refractive power and a second lens unit having a negative refractive power, configured to change a focal length thereof by varying an airspace reserved between the first and second lens units, and suited for use in electronic image pickup apparatus. The first lens unit is composed only of a single homogeneous lens element and the second lens unit is composed of a single radial type gradient index lens element which has a positive power of medium.

Abstract: An optical system comprising a radial type gradient index lens element which has a negative refractive power of medium and a negative refractive power as a whole, and a radial type gradient index lens element which has a negative refractive power of medium and a negative refractive power as a whole; the optical system having favorable imaging performance: and an optical module using the optical system which is suited for stereoscopic photography and automatic focusing.

Abstract: A gradient index lens component composed of a single radial type gradient index lens element which has planar surfaces on both side and a positive refractive power and comprising an aperture stop which is disposed in the vicinity of an object side surface of the radial gradient index lens element for restricting a light bundle. And an image pickup apparatus composed by integrating the gradient index lens component with an image pickup device.

Abstract: Acceleration corresponding to individual cylinders can be measured by an apparatus. The apparatus comprises a crankshaft position sensor providing position signals, and a device including a programmed control unit. The device measures a first time period of rotation through a first rotation interval defined by first selected position signals separated by a first angle of rotation. It measures a second time period of rotation through a second rotation interval defined by second selected position signals separated by a second angle of rotation. It also measures a third time period of rotation between the first and second rotation intervals. Each of the first and second rotation intervals includes a selected power stroke. The first instantaneous speed is calculated as a function of the first measured time period and the second instantaneous speed is calculated as a function of the second measured time period.

Abstract: An eyepiece system comprising a single radial type gradient index lens which has a refractive index varying dependently on distances from an optical axis in a radial direction and a negative power. This eyepiece system is composed of a small number of lenses, and has chromatic aberration, curvature of field, spherical aberration, etc. which are corrected favorably.