Abstract: A fuel vapor treating mechanism includes a canister for adsorbing fuel vapor produced in a fuel feed system. The treating mechanism purges the fuel vapor adsorbed by the canister, along with air, to an intake system of the engine. An ECU computes a value representing the flow rate of the purged gas as a value that represents the capability of the treating apparatus. The ECU sets a decision value in accordance with the amount of the fuel vapor produced in the fuel feed system. The decision value represents a required capability of the treating mechanism. When the value representing the capability is less than the decision value, the ECU prohibits stratified charge combustion and causes the engine to perform homogeneous charge combustion. Therefore, as many opportunities as possible are provided to perform stratified charge combustion, which improves fuel efficiency.

Abstract: An engine output for bringing the drive power of a motor vehicle to a requested value is determined as a target output. One of the lean burn and the stoichiometric burn is selected as a combustion form that achieves a best fuel consumption performance in terms of the control of the actual engine output to the target output. That is, an output value that serves as a criterion for determining whether to switch the combustion force is determined based on the minimum fuel consumption rate during the stoichiometric-burn operation and the minimum fuel consumption rate during the lean-burn operation in which the fuel consumption involved in the rich spike control is taken into account. If the target output is less than the output value, the lean-burn operation is performed. If the target output is greater than the output value, the stoichiometric-burn operation is performed.

Abstract: A speed change control system for a continuously variable transmission, for controlling a gear ratio by deciding an abrupt acceleration demand of a driver, to effect an abrupt speed change when it is decided that the driver demands an abrupt acceleration. The speed change control system comprises: a drive state decider for deciding that the vehicle has changed from a driven state to a drive state, when said abrupt acceleration is demanded at the driven state; and a speed change controller for controlling said continuously variable transmission to effect said abrupt speed change, after said drive state decider decides that the vehicle has changed from the driven state to the drive state.

Abstract: An engine has an improved fuel injection control apparatus the pressure boosting and method that prevents misfire and prevents unburned fuel from entering the exhaust system. The fuel injection system has two pumps, a primary pump and a booster pump. When an abnormality occurs in the booster pump, it is stopped, and fuel injection is performed by the primary pump. When the booster pump is stopped, a fuel injection valve or an air intake device is regulated such that the air/fuel mixture formed in the combustion chambers will not misfire, and unburned fuel will not remain and enter the exhaust system.

Abstract: A vehicle drive power control apparatus and method control the speed ratio of a transmission based on a speed shift line that is set so that, within a practical region, the speed shift line is in a low revolution speed side of an optimal fuel consumption line determined based on the efficiency of the engine and the efficiency of the transmission. Therefore, the width of increase in revolution speed from the speed occurring at the beginning of the practical region is curbed. Hence, the fuel consumption resulting from inertia torques caused by fluctuations in engine revolution speed, that is, fluctuations in the revolution speed of the input shaft of the transmission and a fluidic power transfer mechanism, is reduced, so that the efficiency as a whole increases and the fuel economy improves in comparison with the case where the optimal fuel consumption line is used as a control basis.

Abstract: A target driving force is calculated by an ECU on the basis of an accelerator opening and a vehicle speed, and a rounded target driving force value (or a corrected target driving force), as gradually changed from the driving force, is determined in the course to reach the target driving force. On the other hand, a rounded target power value (or a corrected target power) is determined on the basis of the rounded target driving force value. Moreover, the gear ratio of a CVT is controlled according to a target power calculated on the basis of the target driving force, and the load on an engine is controlled on the basis of the rounded target power value, so that the reduction in the power characteristics or the physical discomfort, as might otherwise be caused by the difference in the response between the engine and the CVT, is loosened.

Abstract: A fuel injection controller of a cylinder injection engine selects an injection mode from various fuel injection modes including an intake stroke injection mode, in which fuel is injected during an intake stroke, and a compression stroke injection mode, in which fuel is injected during a compression stroke. The controller includes a selector for selecting the compression stroke injection mode when the engine is cool if the temperature of the engine when the engine is started is within a predetermined temperature range and for selecting the intake stroke injection mode when the engine is cool if the temperature of the engine when the engine is started is higher than the predetermined temperature range.

Abstract: A fuel supply amount control apparatus for an internal combustion engine uses an idling control amount QISC obtained by reducing an idling control amount Qa by an idling control amount correction value KQISC, when determining the amount of fuel injected for the lean combustion when the vehicle is running. Therefore, during the lean combustion with the D range is selected, there is substantially no difference between the road load amount of fuel injected during the idling state and the road load amount of fuel injected during a low-speed running of the vehicle. Hence, an increase in the amount of fuel injection during the low-speed running of the vehicle based on the lean combustion achieved upon a fuel increase request does not result in an excessively great output torque of the engine, so that the low-speed running of the vehicle becomes stable and good drivability can be maintained.

Abstract: A vehicle drive power control apparatus and method control the speed ratio of a transmission based on a speed shift line that is set so that, within a practical region, the speed shift line is in a low revolution speed side of an optimal fuel consumption line determined based on the efficiency of the engine and the efficiency of the transmission. Therefore, the width of increase in revolution speed from the speed occurring at the beginning of the practical region is curbed. Hence, the fuel consumption resulting from inertia torques caused by fluctuations in engine revolution speed, that is, fluctuations in the revolution speed of the input shaft of the transmission and a fluidic power transfer mechanism, is reduced, so that the efficiency as a whole increases and the fuel economy improves in comparison with the case where the optimal fuel consumption line is used as a control basis.

Abstract: A method and apparatus control an emission of an internal combustion engine. The emission control of the internal combustion engine has a three-way catalyst and a NOx storage-reduction catalyst in an exhaust passage. The emission control reduces NOx stored in the catalyst to recover its NOx storing capability by performing a rich spike control during a lean burn operation. The emission control apparatus has an electronic control unit that limits the execution time of the rich spike control and, after the elapse of the limited execution time, performs a stoichiometric burn operation. The emission control prevents prolongation of the rich spike control and thereby prevents deterioration of HC and CO emissions. By performing the stoichiometric burn operation after the elapse of the limited time of the rich spike control, the emission control apparatus recovers the NOx storing capability while avoiding deterioration of HC and CO emissions.

Abstract: An apparatus for detecting a concentration of a vapor fuel in a lean-burn internal combustion engine includes a module for performing purge concentration learning when in a lean-burn where an air/fuel ratio sensor does not sufficiently work. When detecting the concentration of the vapor fuel during a lean-burn operation of the internal combustion engine, the internal combustion engine is switched over to a homogeneous combustion operation from a lean-burn operation, and the concentration of the vapor fuel is detected under the homogeneous combustion operation. Alternatively, the combustion is switched over to the homogeneous combustion when in a rich spike and when ensuring a brake negative pressure, and hence the concentration of the vapor fuel is detected by utilizing this timing. The thus detected and learned concentration of the vapor fuel is utilized for the purge control when in the lean-burn.

Abstract: An apparatus for detecting a concentration of a vapor fuel in a lean-burn internal combustion engine includes a module for performing purge concentration learning when in a lean-burn where an air/fuel ratio sensor does not sufficiently work. When detecting the concentration of the vapor fuel during a lean-burn operation of the internal combustion engine, the internal combustion engine is switched over to a homogeneous combustion operation from a lean-burn operation, and the concentration of the vapor fuel is detected under the homogeneous combustion operation. Alternatively, the combustion is switched over to the homogeneous combustion when in a rich spike and when ensuring a brake negative pressure, and hence the concentration of the vapor fuel is detected by utilizing this timing. The thus detected and learned concentration of the vapor fuel is utilized for the purge control when in the lean-burn.

Abstract: A fuel supply amount control apparatus for an internal combustion engine uses an idling control amount QISC obtained by reducing an idling control amount Qa by an idling control amount correction value KQISC, when determining the amount of fuel injected for the lean combustion when the vehicle is running. Therefore, during the lean combustion with the D range is selected, there is substantially no difference between the road load amount of fuel injected during the idling state and the road load amount of fuel injected during a low-speed running of the vehicle. Hence, an increase in the amount of fuel injection during the low-speed running of the vehicle based on the lean combustion achieved upon a fuel increase request does not result in an excessively great output torque of the engine, so that the low-speed running of the vehicle becomes stable and good drivability can be maintained.

Abstract: A brake booster is actuated based on negative pressure in an intake passage. When an engine is operating in the stratified charge combustion, an ECU decreases the throttle opening size to lower the pressure in the intake passage if the pressure in the brake booster, or a booster working pressure, is higher than a demanded value. When the booster working pressure is lower than the demanded value, the ECU increases the throttle opening size as the difference between the booster working pressure and the demanded value increases. Therefore, when the difference between the booster working pressure and the demanded value is small, the booster working pressure is rapidly lowered if the booster working pressure increases above the demanded value. When the difference between the booster working pressure and the demanded value is great, the pumping loss of the engine is decreased.

Abstract: A speed change control system for a continuously variable transmission, for controlling a gear ratio by deciding an abrupt acceleration demand of a driver, to effect an abrupt speed change when it is decided that the driver demands an abrupt acceleration. The speed change control system comprises: a drive state decider for deciding that the vehicle has changed from a driven state to a drive state, when said abrupt acceleration is demanded at the driven state; and a speed change controller for controlling said continuously variable transmission to effect said abrupt speed change, after said drive state decider decides that the vehicle has changed from the driven state to the drive state.

Abstract: An engine output for bringing the drive power of a motor vehicle to a requested value is determined as a target output. One of the lean burn and the stoichiometric burn is selected as a combustion form that achieves a best fuel consumption performance in terms of the control of the actual engine output to the target output. That is, an output value that serves as a criterion for determining whether to switch the combustion force is determined based on the minimum fuel consumption rate during the stoichiometric-burn operation and the minimum fuel consumption rate during the lean-burn operation in which the fuel consumption involved in the rich spike control is taken into account. If the target output is less than the output value, the lean-burn operation is performed. If the target output is greater than the output value, the stoichiometric-burn operation is performed.

Abstract: An engine has an improved fuel injection control apparatus the pressure boosting and method that prevents misfire and prevents unburned fuel from entering the exhaust system. The fuel injection system has two pumps, a primary pump and a booster pump. When an abnormality occurs in the booster pump, it is stopped, and fuel injection is performed by the primary pump. When the booster pump is stopped, a fuel injection valve or an air intake device is regulated such that the air/fuel mixture formed in the combustion chambers will not misfire, and unburned fuel will not remain and enter the exhaust system.

Abstract: An apparatus for detecting a concentration of a vapor fuel in a lean-burn internal combustion engine includes a module for performing purge concentration learning when in a lean-burn where an air/fuel ratio sensor does not sufficiently work. When detecting the concentration of the vapor fuel during a lean-burn operation of the internal combustion engine, the internal combustion engine is switched over to a homogeneous combustion operation from a lean-burn operation, and the concentration of the vapor fuel is detected under the homogeneous combustion operation. Alternatively, the combustion is switched over to the homogeneous combustion when in a rich spike and when ensuring a brake negative pressure, and hence the concentration of the vapor fuel is detected by utilizing this timing. The thus detected and learned concentration of the vapor fuel is utilized for the purge control when in the lean-burn.

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 engine 1 is provided with a fuel injection valve 11 for injecting fuel to be supplied to each of cylinders #1 to #4. An electrical control unit (ECU) 30 increases or decreases both a fuel injection amount and an exhaust gas recirculation (EGR) amount so as to quickly approximate torque variation of the engine 1 to a target value. By increasing or decreasing the fuel injection amount so that the target value of the torque variation is in an area of the EGR amount in which the torque variation does not excessively change with the change of the EGR amount, the torque variation is prevented from being largely displaced from the target value on the increase side.