Abstract: The combustion air-fuel ratio is made leaner than the stoichiometric air-fuel ratio at the time of engine startup and the combustion air-fuel ratio is made richer than the stoichiometric air-fuel ratio and the exhaust downstream part of the three-way catalyst apparatus is raised in temperature when it is judged that just the exhaust upstream part of the three-way catalyst apparatus arranged in the engine exhaust system has been raised to the catalyst activation temperature.

Abstract: A catalyst for purifying exhaust gases includes a support substrate, and a catalytic loading layer. The support substrate has an exhaust-gas flow passage. The catalytic loading layer is formed on a surface of the exhaust-gas flow passage, and is composed of a porous oxide support and a catalytic ingredient. The catalytic loading layer includes an Rh area, and an oxidizing area. On the Rh area, rhodium is loaded as the catalytic ingredient. The oxidizing area is formed on an exhaust-gas flow downstream side with respect to the Rh area. On the oxidizing area, a catalytic ingredient exhibiting an oxidizing activity at least is loaded. Also disclosed is an exhaust-gas purification controller using the same.

Abstract: A PM sensor for measuring particle matter in exhaust gas is disposed between a three-way catalyst and a muffler in an exhaust pipe, and has an oxidation catalyst and an electrical heater that are stacked together, and a temperature sensor that measures a temperature of the oxidation catalyst interposed between the oxidation catalyst and the electrical heater. The oxidation catalyst carries a ceria as an oxygen-storing agent that occludes oxygen in the exhaust gas, and a ECU calculates a sediment amount of the exhaust particulate matter based on an amount of temperature rise when the electrical heater heats the oxidation catalyst and an accumulated value of an intake air amount.

Abstract: A catalyst for purifying exhaust gases includes a carrier substrate and a catalyst layer which is carried on the carrier substrate and contains a noble metal, a porous oxide and an addition oxide containing at least one selected from the group consisting of Ni, Bi, Sn, Fe, Co, Cu and Zn. Only a downstream section of the carrier substrate, which is located on a downstream side of an exhaust gas stream contains the addition oxide, whereas an upstream section of the carrier substrate does not contain the addition oxide. With this arrangement, in the upstream section of the carrier substrate, the noble metal and the addition oxide do not exist together so that the noble metal is not deteriorated with the addition oxide. As a result, in the upstream section, the purification performance as a three-way catalyst is favorably achieved, thereby restraining the emission of H2S while maintaining the three-way performance.

Abstract: An air-fuel ratio control system maintaining constant an oxygen storage amount or oxygen release amount per unit time with respect to an exhaust purification catalyst having an oxygen storage capacity even if the intake air amount changes is provided.

Abstract: The exhaust gas purifying catalysts sometimes generate H2S which emits exhaust odor under reducing atmosphere. However, in the ordinary air-fuel ratio control, it takes much time to establish sufficient oxygen atmosphere for suppressing H2S emission when the maximum oxygen storage amount which the exhaust gas purifying catalyst can store is large. Thus, the fuel cut control apparatus of an internal combustion engine executes fuel cut to bring oxygen in the exhaust gas into an excessive state when the maximum oxygen storage amount is a predetermined amount or more. As a result, sufficient oxygen can be stored in the exhaust gas purifying catalyst. Even when the maximum oxygen storage amount of the exhaust gas purifying catalyst is smaller than the predetermined amount, if the temperature of the exhaust gas purifying catalyst is lower than predetermined temperature, fuel cut is executed.

Abstract: An air-fuel ratio control system maintaining constant an oxygen storage amount or oxygen release amount per unit time with respect to an exhaust purification catalyst having an oxygen storage capacity even if the intake air amount changes is provided.

Abstract: The output from an air-fuel ratio sensor is corrected using an integral term that is calculated by integrating values of deviation of the output from an oxygen sensor with respect to a reference output that would be obtained when the combustion air-fuel ratio is stoichiometric, when an engine operates with a target combustion air-fuel ratio set to the stoichiometric air-fuel ratio. A fuel-cutoff prohibition period in which fuel supply cutoff is prohibited is set so that the engine continues to operate with the target combustion air-fuel ratio set to the stoichiometric air-fuel ratio, until the integral term is updated at least once. The integral term may be updated when a predetermined updating condition is satisfied.

Abstract: During deterioration detection of a catalyst, exhaust gas of a lean air/fuel ratio and exhaust gas of a rich air/fuel ratio are alternately supplied to the catalyst, and decrease of the O2 storage function is detected by obtaining the oxygen occlusion amount in the catalyst, based upon the timing at which, after changeover of the air/fuel ratio of the exhaust gas flowing into the catalyst, the air/fuel ratio of the exhaust gas passed through the catalyst changes to track that air/fuel ratio of the exhaust gas flowing into the catalyst. At this time, the rich air/fuel ratio of the exhaust gas and the lean air/fuel ratio of the exhaust gas supplied to the catalyst are set closer to the stoichiometric air/fuel ratio, the larger is the exhaust flow amount.

Abstract: A catalyst is positioned in an exhaust path of an internal-combustion engine. A main air-fuel ratio sensor and sub-oxygen sensor are respectively positioned upstream and downstream of the catalyst. A main feedback operation is performed so that the output of the main air-fuel ratio sensor is fed back and reflected in the fuel injection quantity until the control A/F prevailing upstream of the catalyst coincides with the target A/F. A sub-feedback operation is performed so that the output of the sub-oxygen sensor is fed back and reflected in the fuel injection quantity until the air-fuel ratio of an exhaust gas flowing out of the catalyst agrees with a theoretical air-fuel ratio. Since a catalyst window varies in accordance with the intake air quantity, the fuel injection quantity is corrected so that the larger the intake air quantity becomes, the richer the control A/F is.

Abstract: A target air-fuel ratio of exhaust gas is changed back and forth between rich and lean in short periods, and it is determined that the catalyst is degraded when the air-fuel ratio of exhaust gas is lean by the time a predetermined period of time has passed from the time the target air-fuel ratio started to be changed.

Abstract: The exhaust gas purifying catalysts sometimes generate H2S which emits exhaust odor under reducing atmosphere. However, in the ordinary air-fuel ratio control, it takes much time to establish sufficient oxygen atmosphere for suppressing H2S emission when the maximum oxygen storage amount which the exhaust gas purifying catalyst can store is large. Thus, the fuel cut control apparatus of an internal combustion engine executes fuel cut to bring oxygen in the exhaust gas into an excessive state when the maximum oxygen storage amount is a predetermined amount or more. As a result, sufficient oxygen can be stored in the exhaust gas purifying catalyst. Even when the maximum oxygen storage amount of the exhaust gas purifying catalyst is smaller than the predetermined amount, if the temperature of the exhaust gas purifying catalyst is lower than predetermined temperature, fuel cut is executed.

Abstract: A catalyst is positioned in an exhaust path of an internal-combustion engine. A main air-fuel ratio sensor and sub-oxygen sensor are respectively positioned upstream and downstream of the catalyst. A main feedback operation is performed so that the output of the main air-fuel ratio sensor is fed back and reflected in the fuel injection quantity until the control A/F prevailing upstream of the catalyst coincides with the target A/F. A sub-feedback operation is performed so that the output of the sub-oxygen sensor is fed back and reflected in the fuel injection quantity until the air-fuel ratio of an exhaust gas flowing out of the catalyst agrees with a theoretical air-fuel ratio. Since a catalyst window varies in accordance with the intake air quantity, the fuel injection quantity is corrected so that the larger the intake air quantity becomes, the richer the control A/F is.

Abstract: An apparatus is for purifying exhaust gases, and includes an HC adsorption-purifying catalyst and a three-way catalyst. The HC adsorption-purifying catalyst includes an HC adsorbent, and an oxidizing catalyst. The three-way catalyst is disposed on an upstream side of the flow of exhaust gases with respect to the HC adsorption-purifying catalyst, wherein a noble metal is loaded higher on a high loading portion disposed on an upstream part of the three-way catalyst than on an ordinary part of the three-way catalyst. The apparatus shows the actions of the three-way catalyst and the actions of the HC adsorption-purifying catalyst synergistically, and accordingly can remarkably inhibit the HC emission even in low-temperature regions such as when engines are started.

Abstract: A cathode ray tube display in which a signal for detection of a cathode current is inserted into a part of the vertical blanking period of the video signal to be displayed, a cathode current corresponding to the signal for detection is detected, and a cathode voltage or a grid voltage is negative feedback controlled so that the detected cathode current becomes constant, thereby stabilizing the cathode current. The display has a local overscan circuit for executing a vertical scan on the screen with a width larger than a predetermined scan width only at a timing of the cathode current detecting signal inserted for a vertical blanking period, and even in the case where an underscan system to scan by a width smaller than a predetermined display screen width is used as a scan system of the screen display. The invention prevents a harmful visible display image by the cathode current detecting signal appears on the screen.

Abstract: A video output circuit of a wide bandwidth comprises a bridged-T-type circuit, a first inductor connected in series to the bridged-T-type circuit, and a shunt circuit connected in series to the bridged-T-type circuit and including a second inductor and a first resistor connected in parallel with each other. The bridged-T-type circuit, the first inductor and the shunt circuit cooperate to constitute together with a plurality of stray capacitors a low-pass filter whose order is at least 4 and whose merit index is at least 3.

Abstract: A video output circuit for driving a CRT of a grid-cathode differential drive type is disclosed, in which a collector potential of an output transistor in a horizontal blanking interval is detected by a diode arrangement; the potential thus detected is smoothed by a smoothing filtering arrangement output current of the output transistor is controlled by an output obtained by the smoothing filtering arrangement; and negative feedback control is effected so that the collector potential of the output transistor is made constant. In this way, a bias adjusting power supply, which was required heretofore, is made unnecessary.