Abstract: An upper-limit threshold value and a lower-limit threshold value of a fore-and-aft differential pressure of an EGR control valve is calculated based on an intake-air quantity detected by an airflow meter. An actual fore-and-aft differential pressure of the EGR control valve is calculated from detected values of an upstream-side pressure sensor and a downstream-side pressure sensor. Then, these threshold values are compared with the actual fore-and-aft differential pressure, and when the actual fore-and-aft differential pressure exceeds the upper-limit threshold value or when the actual fore-and-aft differential pressure is less than the lower-limit threshold value, it is determined that the pressure loss of an intake and exhaust system has changed. If it is determined that the pressure loss of an intake and exhaust system has changed, EGR is inhibited, and if not so, EGR is permitted to be performed. These threshold values are varied depending on a target EGR rate.

Abstract: There is provided a control device of an engine that includes a turbo-supercharger and a variable valve mechanism, the control device including: a valve timing change means; an ignition timing change means; a fuel injection amount change means; an acceleration request detection means; a supercharging pressure detection means; and an acceleration control means that corrects, when the acceleration request is detected, retarding of ignition timing in a low supercharging region where the supercharging pressure is lower than a predetermined value, that completes the correction of the retarding of the ignition timing in a high supercharging region where the supercharging pressure is equal to or higher than the predetermined value to provide a valve overlap and that changes the fuel injection amount such that an air-fuel ratio at which a mixture air of a scavenging gas and an exhaust gas is easily burned within an exhaust passage is provided.

Abstract: Provided is a control device for a multi-cylinder internal combustion engine, including: a supercharger to be driven by exhaust gas energy; and a fuel injection control unit, in which the fuel injection control unit sets a fuel injection amount for one cylinder so that an air/fuel ratio in the one cylinder is richer than a theoretical air/fuel ratio, and exhaust gas exhausted when the one cylinder is in an exhaust stroke and scavenging gas scavenged during a valve overlap period from another cylinder which is in an intake stroke when the one cylinder is in the exhaust stroke are mixed in an exhaust pipe so as to attain an air/fuel ratio facilitating combustion.

Abstract: A control device for an internal combustion engine with a turbo-supercharger including a variable valve mechanism at least at either one of an intake side and an exhaust side includes a scavenging amount setting means for determining an upper limit value of a scavenging amount moving from an intake passage to an exhaust passage across the interior of a cylinder during a valve overlap period to satisfy a performance requirement for the internal combustion engine, and a variable valve control means for controlling the duration of the valve overlap period according to the scavenging amount.

Abstract: An upper-limit threshold value and a lower-limit threshold value of a fore-and-aft differential pressure of an EGR control valve is calculated based on an intake-air quantity detected by an airflow meter. An actual fore-and-aft differential pressure of the EGR control valve is calculated from detected values of an upstream-side pressure sensor and a downstream-side pressure sensor. Then, these threshold values are compared with the actual fore-and-aft differential pressure, and when the actual fore-and-aft differential pressure exceeds the upper-limit threshold value or when the actual fore-and-aft differential pressure is less than the lower-limit threshold value, it is determined that the pressure loss of an intake and exhaust system has changed. If it is determined that the pressure loss of an intake and exhaust system has changed, EGR is inhibited, and if not so, EGR is permitted to be performed. These threshold values are varied depending on a target EGR rate.

Abstract: An exhaust gas recirculation device for an internal combustion engine having a supercharger has an intake air passage that intakes intake air for the internal combustion engine, an exhaust passage that carries away exhaust air from the internal combustion engine, an exhaust gas recirculation passage connected to the intake air passage, and an exhaust gas recirculation valve interposed within the exhaust gas recirculation passage. The exhaust gas recirculation passage recirculates a part of the exhaust gas based on an openness of the exhaust gas recirculation valve to control an amount of exhaust recirculation introduced into the intake air passage. A first end of the exhaust gas recirculation passage is connected to the intake air passage upstream of a compressor of the supercharger. A second end of the exhaust gas recirculation passage is connected to the exhaust passage downstream of a turbine of the supercharger.

Abstract: Provided is a control device for an internal combustion engine equipped with a supercharger, including: operation state detection means for detecting an operation state of the internal combustion engine; overlap read means for reading a valve overlap period; collector pressure detection means for detecting a collector pressure; exhaust gas pressure estimation means for estimating an exhaust gas pressure on an upstream side of the supercharger; and scavenging amount estimation means for estimating a scavenging amount based on the operation state, the valve overlap period, the collector pressure, and the exhaust gas pressure.

Abstract: A control system for a direct-injection four-stroke internal combustion engine having at least one cylinder, an intake passage supplying air to the cylinder, and an exhaust passage removing exhaust gas from the cylinder, the control system including a mass air flow meter configured to detect a mass air flow upstream of the cylinder and a control unit. The control unit is configured to detect an intake air density in the cylinder, calculate an in-cylinder trapped intake air amount based on a cylinder volume and the detected intake air density, and estimate a difference between the intake air amount detected by the mass air flow meter and the in-cylinder trapped intake air amount, the estimated difference being an estimated scavenging amount representing a fresh air blowby amount passing from the intake passage into the exhaust passage.

Abstract: Provided is a control device for a multi-cylinder internal combustion engine, including: a supercharger to be driven by exhaust gas energy; and a fuel injection control unit, in which the fuel injection control unit sets a fuel injection amount for one cylinder so that an air/fuel ratio in the one cylinder is richer than a theoretical air/fuel ratio, and exhaust gas exhausted when the one cylinder is in an exhaust stroke and scavenging gas scavenged during a valve overlap period from another cylinder which is in an intake stroke when the one cylinder is in the exhaust stroke are mixed in an exhaust pipe so as to attain an air/fuel ratio facilitating combustion.

Abstract: Provided is a control device for an internal combustion engine equipped with a supercharger, including: operation state detection means for detecting an operation state of the internal combustion engine; overlap read means for reading a valve overlap period; collector pressure detection means for detecting a collector pressure; exhaust gas pressure estimation means for estimating an exhaust gas pressure on an upstream side of the supercharger; and scavenging amount estimation means for estimating a scavenging amount based on the operation state, the valve overlap period, the collector pressure, and the exhaust gas pressure.

Abstract: There is provided a control device of an engine that includes a turbo-supercharger and a variable valve mechanism, the control device including: a valve timing change means; an ignition timing change means; a fuel injection amount change means; an acceleration request detection means; a supercharging pressure detection means; and an acceleration control means that corrects, when the acceleration request is detected, retarding of ignition timing in a low supercharging region where the supercharging pressure is lower than a predetermined value, that completes the correction of the retarding of the ignition timing in a high supercharging region where the supercharging pressure is equal to or higher than the predetermined value to provide a valve overlap and that changes the fuel injection amount such that an air-fuel ratio at which a mixture air of a scavenging gas and an exhaust gas is easily burned within an exhaust passage is provided.

Abstract: A control device for an internal combustion engine with a turbo-supercharger including a variable valve mechanism at least at either one of an intake side and an exhaust side includes a scavenging amount setting means for determining an upper limit value of a scavenging amount moving from an intake passage to an exhaust passage across the interior of a cylinder during a valve overlap period to satisfy a performance requirement for the internal combustion engine, and a variable valve control means for controlling the duration of the valve overlap period according to the scavenging amount.

Abstract: A control system for a direct-injection four-stroke internal combustion engine having at least one cylinder, an intake passage supplying air to the cylinder, and an exhaust passage removing exhaust gas from the cylinder, the control system including a mass air flow meter configured to detect a mass air flow upstream of the cylinder and a control unit. The control unit is configured to detect an intake air density in the cylinder, calculate an in-cylinder trapped intake air amount based on a cylinder volume and the detected intake air density, and estimate a difference between the intake air amount detected by the mass air flow meter and the in-cylinder trapped intake air amount, the estimated difference being an estimated scavenging amount representing a fresh air blowby amount passing from the intake passage into the exhaust passage.

Abstract: An exhaust gas recirculation device for an internal combustion engine having a supercharger has an intake air passage that intakes intake air for the internal combustion engine, an exhaust passage that carries away exhaust air from the internal combustion engine, an exhaust gas recirculation passage connected to the intake air passage, and an exhaust gas recirculation valve interposed within the exhaust gas recirculation passage. The exhaust gas recirculation passage recirculates a part of the exhaust gas based on an openness of the exhaust gas recirculation valve to control an amount of exhaust recirculation introduced into the intake air passage. A first end of the exhaust gas recirculation passage is connected to the intake air passage upstream of a compressor of the supercharger. A second end of the exhaust gas recirculation passage is connected to the exhaust passage downstream of a turbine of the supercharger.

Abstract: A leak diagnostic apparatus for a vaporized fuel processing system that purges vaporized fuel in a fuel tank of a vehicle is disclosed. The leak diagnostic apparatus comprises a leak diagnostic device, a fuel tank condition detection device and a determining device. The leak diagnostic device carries out a leak diagnosis of the vaporized fuel processing system while the engine is operating. The fuel tank condition detection device detects the conditions in the fuel tank. The determining device determines whether the leak diagnosis should be carried out based on predetermined conditions in the fuel tank.

Abstract: A fuel vapor purge system is configured to execute a highly accurate leak diagnosis with respect to a fuel vapor leak. After the engine is stopped, the temperature of the fuel vapor rises temporarily and then decreases until it reaches the outside ambient temperature. During this period, the purge line is closed off and a purge line pressure decreasing rate is detected when the purge line pressure is slightly above atmospheric pressure. The detected purge line pressure decreasing rate is then compared to a threshold value. The purge system is diagnosed as “normal” if the purge line pressure decreasing rate is equal to or larger than the threshold value and as “leaking” if the purge line pressure decreasing rate is less than the threshold value.

Abstract: A fuel vapor purge system is configured to execute a highly accurate leak diagnosis with respect to a fuel vapor leak. After the engine is stopped, the temperature of the fuel vapor rises temporarily and then decreases until it reaches the outside ambient temperature. During this period, the purge line is closed off and a minimum value reached by the purge line pressure is detected. The difference between the minimum value of the purge line pressure and the atmospheric pressure is compared to a threshold value. The purge system is diagnosed as “normal” if the difference is equal to or larger than the threshold value and a “leaking” if the difference is less than the threshold value.

Abstract: Disclosed is a leak detecting device for a fuel vapor treatment unit that purges a vapor gas generated through evaporation of fuel in a fuel tank (2) into an intake system (22) of an engine (21). The leak detecting device includes a valve (5) that can selectively seal the fuel vapor treatment unit; a pressure detecting sensor (8) that detects a pressure in the fuel vapor treatment unit; and a controller (10). The controller (10) is programmed to: issue a command to close the valve (5) with a view to sealing the fuel vapor treatment unit during stoppage of the engine (21); calculate deviation amounts (P?P0) of the detected pressures during stoppage of the engine (21) after the fuel vapor treatment unit has been sealed; integrate absolute values (|P?P0|) of the deviation amounts, and determine, based on an integrated value (s), whether or not there is a leak occurring in the fuel vapor treatment unit.

Abstract: A leak diagnostic apparatus for a vaporized fuel processing system that purges vaporized fuel in a fuel tank of a vehicle is disclosed. The leak diagnostic apparatus comprises a leak diagnostic device, a fuel tank condition detection device and a determining device. The leak diagnostic device carries out a leak diagnosis of the vaporized fuel processing system while the engine is operating. The fuel tank condition detection device detects the conditions in the fuel tank. The determining device determines whether the leak diagnosis should be carried out based on predetermined conditions in the fuel tank.

Abstract: A fuel vapor purge system is configured to execute a highly accurate leak diagnosis with respect to a fuel vapor leak. After the engine is stopped, the temperature of the fuel vapor rises temporarily and then decreases until it reaches the outside ambient temperature. During this period, the purge line is closed off and a purge line pressure decreasing rate is detected when the purge line pressure is slightly above atmospheric pressure. The detected purge line pressure decreasing rate is then compared to a threshold value. The purge system is diagnosed as “normal” if the purge line pressure decreasing rate is equal to or larger than the threshold value and as “leaking” if the purge line pressure decreasing rate is less than the threshold value.