Abstract: An exhaust gas purifying apparatus for an internal combustion engine having an exhaust system. The exhaust gas purifying apparatus includes a NOx purifying device provided in the exhaust system for purifying NOx in exhaust gases, and a temperature sensor for detecting a temperature of the NOx purifying device. The NOx purifying device has NOx adsorbing capacity and generates ammonia and retains the generated ammonia when the air-fuel ratio is set to a value on the rich side with respect to the stoichiometric ratio. The NOx purifying device purifies NOx with the retained ammonia when the air-fuel ratio is set to a value on a lean side with respect to the stoichiometric ratio. The air-fuel ratio is enriched to a value on the rich side with respect to the stoichiometric ratio so as to increase an amount of reducing components in the exhaust gases flowing into the NOx purifying device.

Abstract: A NOx removing device 4 having NOx absorbing capacity and ammonia retaining capacity is provided in an exhaust pipe 2 of an internal combustion engine 1. A reforming catalyst 3 is disposed upstream of the NOx removing device 4. The reforming catalyst 3 generates hydrogen and carbon monoxide by the steam reforming reaction, when the exhaust gases are in the reducing state. Hydrogen and carbon monoxide generated by the reforming catalyst 3 are supplied to the NOx removing device 4, and contribute to generation of ammonia. The generated ammonia is retained in the NOx removing device 4 and reduces NOx in exhaust gases when the exhaust gases are in the oxidizing state.

Abstract: An exhaust gas purifying apparatus for an internal combustion engine including an ammonia generating device and a NOx removing device. The ammonia generating device is provided in an exhaust system of the engine, and generates ammonia by a reaction of NOx and reducing components in exhaust gases when the exhaust gases are in a reducing state. The NOx removing device is provided downstream of the ammonia generating device, and adsorbs NOx in the exhaust gases when the exhaust gases are in an oxidizing state. The NOx removing device reduces the adsorbed NOx to generate ammonia and retains the generated ammonia when the exhaust gases are in the reducing state.

Abstract: There is provided a valve timing control system for an internal combustion engine, which makes it possible to secure a right amount of combustion gases in a combustion chamber, irrespective of whether an EGR device is in operation or not, thereby obtaining a sufficient effect of reduced exhaust emissions by reduction of NOx. A crank angle position sensor and an intake pipe absolute pressure sensor detect operating conditions of the engine. An ECU determines whether the EGR device is in operation or not. A target cam phase is set in dependence on the detected operating conditions of the engine and a result of the determination as to whether the EGR device is in operation or not, and the cam phase is controlled to the target cam phase.

Abstract: An exhaust gas purifying apparatus for an internal combustion engine having an exhaust system. The apparatus includes a NOx purifying device provided in the exhaust system. This device removes NOx from exhaust gases when a concentration of oxygen in the exhaust gases is higher than a concentration of reducing components in the exhaust gases; generates ammonia and retains the generated ammonia when the concentration of reducing components in the inflowing exhaust gases is higher than the concentration of oxygen; and purifies NOx with the retained ammonia when the concentration of reducing components in the inflowing exhaust gases is lower than the concentration of oxygen. A residual amount of ammonia retained in the NOx purifying device is estimated. The concentration of reducing components in the exhaust gases is switched with respect to the concentration of oxygen according to the estimated residual amount.

Abstract: An exhaust gas purifying apparatus for an internal combustion engine having an exhaust system. The exhaust gas purifying apparatus includes a NOx purifying device provided in the exhaust system for purifying NOx in exhaust gases, and a temperature sensor for detecting a temperature of the NOx purifying device. The NOx purifying device has NOx absorbing capacity and generates ammonia and retains the generated ammonia when the air-fuel ratio is set to a value on the rich side with respect to the stoichiometric ratio. The NOx purifying device purifies NOx with the retained ammonia when the air-fuel ratio is set to a value on a lean side with respect to the stoichiometric ratio. The air-fuel ratio is enriched to a value on the rich side with respect to the stoichiometric ratio so as to increase an amount of reducing components in the exhaust gases flowing into the NOx purifying device.

Abstract: In a system for controlling opening of a throttle valve installed at an air intake system of an internal combustion engine mounted on a vehicle, a fully-closed value of the opening of a throttle valve is learning-controlled based on a detected opening of the throttle valve to update the learned fully-closed value, when operating state of the vehicle is under a prescribed operating state such as the operator rides the accelerator pedal; and the updating of the learned fully-closed value is inhibited in valve opening direction until the operating state of the vehicle moves outside the prescribed operating state and then again returns to the operating state. In addition, an amount for updating in the opening direction is set smaller than that in the closing direction. With this, it becomes possible to avoid engine speed destabilization and other various problems even if the learned value in effect during pedal riding is used for engine idling speed control.

Abstract: There is provided a valve timing control system for an internal combustion engine, which makes it possible to secure a right amount of combustion gases in a combustion chamber, irrespective of whether an EGR device is in operation or not, thereby obtaining a sufficient effect of reduced exhaust emissions by reduction of NOx. A crank angle position sensor and an intake pipe absolute pressure sensor detect operating conditions of the engine. An ECU determines whether the EGR device is in operation or not. A target cam phase is set in dependence on the detected operating conditions of the engine and a result of the determination as to whether the EGR device is in operation or not, and the cam phase is controlled to the target cam phase.

Abstract: In a system for controlling opening of a throttle valve installed at an air intake system of an internal combustion engine mounted on a vehicle, a fully-closed value of the opening of a throttle valve is learning-controlled based on a detected opening of the throttle valve to update the learned fully-closed value, when operating state of the vehicle is under a prescribed operating state such as the operator rides the accelerator pedal; and the updating of the learned fully-closed value is inhibited in valve opening direction until the operating state of the vehicle moves outside the prescribed operating state and then again returns to the operating state. In addition, an amount for updating in the opening direction is set smaller than that in the closing direction. With this, it becomes possible to avoid engine speed destabilization and other various problems even if the learned value in effect during pedal riding is used for engine idling speed control.