Abstract: A NOx reduction catalyst is provided which reduces NOx in processing gas. The NOx reduction catalyst includes a catalyst substrate containing an oxide, a NOx absorption component, and a NOx purification component.

Abstract: An internal combustion engine, wherein fuel vapor adsorbed in a canister (22) is purged into a surge tank (13) through a purge control valve (28). A target value of the fuel vapor rate showing the ratio of the amount of fuel vapor in the purge gas to the amount of fuel injection is stored in advance. At least one of the amount of purge gas or the amount of fuel injection is controlled so that the fuel vapor rate becomes the target value.

Abstract: An engine comprising a spark plug and a fuel injector in a combustion chamber and a temperature sensor used to judge if the gas temperature in the combustion chamber is a temperature at which self-ignition occurs when a spark is generated. Based on this judgement, a valve timing device is used to control the opening timing of the intake valve and maintain the gas temperature at a temperature at which self-ignition occurs when a spark is generated.

Abstract: A fuel vapor feed controlling apparatus of a lean burn internal combustion engine suppresses either one of a rich misfire or a surge when fuel vapor is fed into the engine. A purge controlling unit controls an amount of fuel vapor fed from a fuel reservoir to the engine in response to an operational condition of the engine. A first compensation unit compensates the amount of fuel vapor such that an engine revolution speed of the engine may be identical with a target revolution speed. The purge controlling unit performs a purge control based on a compensation value compensated by the first compensation unit.

Abstract: A fuel vapor control apparatus determines whether the concentration of fuel vapor in a space above the surface of liquid fuel in the fuel tank is less than a predetermined concentration. When the concentration of fuel vapor is less than the predetermined concentration, the concentration of fuel vapor in the fuel tank is increased and, when the concentration of fuel vapor exceeds the predetermined concentration, the increase of the concentration of fuel vapor is stopped. Therefore, an amount of fuel flowing out of the fuel tank can be reduced while using a reduced amount of energy.

Abstract: An exhaust gas purifying apparatus of a lean-burn internal combustion engine surely purifies nitrogen oxide occluded by a nitrogen oxide occluding/reducing catalyst without making a combustion of an air-fuel mixture unstable while utilizing a vapor fuel generated in a fuel tank. The exhaust gas purifying apparatus includes a gas state judging unit for judging a state of a vapor fuel gas supplied to an intake system of the lean-burn internal combustion engine, and an exhaust state control unit for setting, to a desired state, a state of the exhaust gas flowing to the nitrogen oxide occluding/reducing catalyst by selectively controlling the fuel injection valve and the gas supply unit in accordance with a state of the vapor fuel gas at the time when the nitrogen oxide occluded by the nitrogen oxide occluding/reducing catalyst provided in an exhaust system of the lean-burn internal combustion engine should be desorbed and purified.

Abstract: A fuel vapor concentration detecting apparatus in a lean-burn internal combustion engine detects a fuel vapor concentration and executes purge control. The apparatus includes an output fluctuation detecting module for detecting, on such an occasion that the fuel vapor is purged into an intake system of the internal combustion engine, an output fluctuation just when the fuel vapor is purged, and a concentration detecting module for calculating the fuel vapor concentration in accordance with a magnitude of the output fluctuation detected by the output fluctuation detecting module. The fuel vapor concentration in the lean-burn internal combustion engine is thus detected. A purge quantity or a state of the fuel injection is changed corresponding to the detected concentration of the fuel vapor.

Abstract: A fuel vapor feed controlling apparatus of a lean burn internal combustion engine suppresses either one of a rich misfire or a surge when fuel vapor is fed into the engine. A purge controlling unit controls an amount of fuel vapor fed from a fuel reservoir to the engine in response to an operational condition of the engine. A first compensation unit compensates the amount of fuel vapor such that an engine revolution speed of the engine may be identical with a target revolution speed. The purge controlling unit performs a purge control based on a compensation value compensated by the first compensation unit.

Abstract: An air-fuel ratio control system for an internal combustion engine. Excessive fuel supplying at fuel cut reset time is avoided, by interrupting the fuel supply when a fuel cut control signal is being output. An amount of fuel cut time during which the fuel cut control signal is output is determined, and a hold time is also determined. This hold time corresponds to an amount of time necessary for combustion gas to reach a feedback sensor, and be included in the feedback control signal, after termination of the fuel cut. A feedback or closed loop system is used during normal operations. An open loop control signal is used during fuel cut time, and for a period of time equivalent to the value of the hold time after the end of this fuel cut time. Therefore, open loop control is used until exhaust gases have again reached the feedback sensor so that feedback or closed loop control can thereafter be used.

Abstract: An air-fuel ratio control apparatus in which air-fuel ratio detecting signal represents air-fuel ratio in a combustion chamber and an integrated amount increased or decreased in relation to the air-fuel ratio detecting signal is calculated from the air-fuel ratio detecting signal on the basis of parameters to correct fuel amount supplied to an intake system on the basis of the integrated amount. The frequency of the air-fuel ratio detecting signal when the air-fuel ratio in the combustion chamber reaches a predetermined value is defined as the basic frequency. To compensate for change with the passage of time in the output characteristics of an air-fuel ratio detecting sensor, said parameter value is corrected so that the frequency of the air-fuel ratio detecting signal becomes the basic frequency.