Abstract: A novel bicyclo derivative represented by the following general formula (1), or a pharmaceutically acceptable salt thereof, acts as an effective DPP-IV inhibitor: One example is (2S,4S)-1-[[N-(4-methylbicyclo[2.2.2]oct-1-yl)amino]acetyl]-4-fluoropyrrolidine-2-carbonitrile).

Abstract: There is provided a method of starting a spark ignition engine having multiple cylinders. The method comprises supplying air and fuel for restart into a first cylinder before the engine completely stops, and igniting the mixture of the air and the fuel in the first cylinder in response to an engine start request. In accordance with the method, by supplying air and fuel into the first cylinder before the engine completely stops, the mixture of air and fuel in the first cylinder may be homogeneous at the time of the engine start request. Also, there may be less mixture turbulence and combustion may propagate better within the cylinder. These conditions may reduce the rate of combustion in the first cylinder after a start request is initiated. The slower combustion rate may decrease temperature of the combusted gas while the cylinder wall temperature is relatively low because the engine has stopped.

Abstract: An exhaust gas purifying apparatus comprises a control unit (29) operative to estimate an amount of NOx absorbed by a NOx trap material (17) disposed in an exhaust passage (10) and to make an air-fuel ratio richer so as thereby to cause the NOx trap material to release sulfur when the estimated amount of NOx absorption exceeds a specified amount. Further, the control unit (29) operative to estimate an amount of sulfur absorbed by the NOx trap material (17) and to make an air-fuel ratio richer and rising a temperature of exhaust gas so as thereby to cause the NOx trap material to release sulfur when the estimated amount of sulfur absorption exceeds a specified amount. The control unit restricts an air-fuel ratio from being made richer when the NOx trap material is not expected to absorb NOx due to progress of sulfur absorption resulting from conditionally the sulfur releasing.

Abstract: An exhaust gas purifying apparatus comprises a control unit (29) operative to estimate an amount of NOx absorbed by a NOx trap material (17) disposed in an exhaust passage (10) and to make an air-fuel ratio richer so as thereby to cause the NOx trap material to release sulfur when the estimated amount of NOx absorption exceeds a specified amount. Further, the control unit (29) operative to estimate an amount of sulfur absorbed by the NOx trap material (17) and to make an air-fuel ratio richer and rising a temperature of exhaust gas so as thereby to cause the NOx trap material to release sulfur when the estimated amount of sulfur absorption exceeds a specified amount. The control means restricts an air-fuel ratio from being made richer when the NOx trap material is not expected to absorb NOx due to progress of sulfur absorption resulting from conditionally the sulfur releasing.

Abstract: In steps S25 to S42, in order to activate an inactive catalyst earlier, the air-fuel ratio in a combustion chamber is set to be &lgr;≈1 during a period T1 after engine start until catalyst light-off at around 50% HC purifying ratio immediately after the HC purifying ratio begins to rapidly rise, before the catalyst warms up, divisional injection is made at least during the period T1 required until light-off is reached, and a swirl is weakened during the period T1 compared to a latter period which follows this period T1. The divisional injection is made and the swirl is strengthened even during the latter period.

Abstract: An exhaust-gas cleaning device comprises an absorption quantity detector (22) for determining the first and second amounts of NOx and oxygen absorbed by a NOx-absorbing material and an oxygen-absorbing material during first and second reference times based on sensing signals fed from an oxygen concentration detector (11), a NOx quantity estimator (23) for obtaining first and second estimated values of the amount of NOx absorbed by the NOx-absorbing material during the first and second reference times in accordance with engine operating condition, and a deterioration detector (24) for making a judgment on deterioration of the NOx-absorbing material based on the first and second amounts of absorption of NOx and oxygen determined by the absorption quantity detector (22) and the first and second estimated values of the amount of NOx obtained by the NOx quantity estimator (23).

Abstract: In steps S25 to S42, in order to activate an inactive catalyst earlier, the air-fuel ratio in a combustion chamber is set to be &lgr;≈1 during a period T1 after engine start until catalyst light-off at around 50% HC purifying ratio immediately after the HC purifying ratio begins to rapidly rise, before the catalyst warms up, divisional injection is made at least during the period T1 required until light-off is reached, and a swirl is weakened during the period T1 compared to a latter period which follows this period T1. The divisional injection is made and the swirl is strengthened even during the latter period.

Abstract: An exhaust-gas cleaning device comprises an absorption quantity detector (22) for determining the first and second amounts of NOx and oxygen absorbed by a NOx-absorbing material and an oxygen-absorbing material during first and second reference times based on sensing signals fed from an oxygen concentration detector (11), a NOx quantity estimator (23) for obtaining first and second estimated values of the amount of NOx absorbed by the NOx-absorbing material during the first and second reference times in accordance with engine operating condition, and a deterioration detector (24) for making a judgment on deterioration of the NOx-absorbing material based on the first and second amounts of absorption of NOx and oxygen determined by the absorption quantity detector (22) and the first and second estimated values of the amount of NOx obtained by the NOx quantity estimator (23).

Abstract: An engine control device, which is adapted for an engine provided with an NOx-absorbing material arranged in an exhaust passage for absorbing NOx in an oxygen-rich atmosphere, and releasing NOx and absorbing sulfur content when the oxygen concentration drops, includes a discriminator for judging whether the amount of sulfur absorbed by the NOx-absorbing material has reached a prescribed quantity, and a reductant concentration controller which increases the temperature of the NOx-absorbing material by decreasing a quantity related to EGR ratio for desulfurizing the NOx-absorbing material based on the result of judgment made by the discriminator. When the quantity related to the EGR ratio is decreased, the temperature of exhaust gas increases. Consequently, the temperature of the NOx-absorbing material increases and the sulfur in the NOx-absorbing material is freed and released.