Abstract: A control apparatus for an internal combustion engine carries out lean combustion to cause flame propagation to a homogeneous air-fuel mixture while drifting primary flames on a tumble flow by injecting fuel for ignition from a second fuel injection valve to a vicinity of an electrode portion and igniting an air-fuel mixture for ignition at a primary ignition timing, and to ignite an air-fuel mixture for accelerating combustion at a secondary ignition timing by injecting fuel for accelerating combustion in a squish area from the second fuel injection valve at a timing before an injection timing of the fuel for ignition and drifting the air-fuel mixture for accelerating combustion in a combustion chamber on the tumble flow. The secondary ignition timing is set as a timing allowing secondary flames produced by igniting the air-fuel mixture for accelerating combustion to be drawn into the squish area by a reverse squish flow.

Abstract: An internal combustion engine includes an ignition plug and an electronic control unit. The electronic control unit is configured to: (i) execute a lean-burn operation in a first operation region, (ii) execute an operation in a second operation region at an air-fuel ratio lower than an air-fuel ratio during the lean-burn operation, and (iii) control a gas flow in a cylinder so that a ratio of a change in a gas flow speed around the ignition plug during ignition to a change in an engine rotation speed in a first engine rotation speed region within the first operation region is smaller than the ratio in a second engine rotation speed region within the second operation region.

Abstract: An internal combustion engine includes an ignition plug and an electronic control unit. The electronic control unit is configured to: (i) execute a lean-burn operation in a first operation region, (ii) execute an operation in a second operation region at an air-fuel ratio lower than an air-fuel ratio during the lean-burn operation, and (iii) control a gas flow in a cylinder so that a ratio of a change in a gas flow speed around the ignition plug during ignition to a change in an engine rotation speed in a first engine rotation speed region within the first operation region is smaller than the ratio in a second engine rotation speed region within the second operation region.

Abstract: An object is to prevent hydrogen from burning before the time of ignition. An internal combustion engine is provided with a first intake port and a second intake port connected to a cylinder, a first fuel injection valve that injects fuel into the first intake port, and an ignition plug provided at a location at which the gas flowing into the cylinder from the second intake port impinges on the ignition plug in a larger quantity than the gas flowing into the cylinder from the second intake port during the intake stroke.

Abstract: An internal combustion engine includes an ignition plug and an electronic control unit. The electronic control unit is configured to: (i) execute a lean-burn operation in a first operation region, (ii) execute an operation in a second operation region at an air-fuel ratio lower than an air-fuel ratio during the lean-burn operation, and (iii) control a gas flow in a cylinder so that a ratio of a change in a gas flow speed around the ignition plug during ignition to a change in an engine rotation speed in a first engine rotation speed region within the first operation region is smaller than the ratio in a second engine rotation speed region within the second operation region.

Abstract: An object is to prevent hydrogen from burning before the time of ignition. An internal combustion engine is provided with a first intake port and a second intake port connected to a cylinder, a first fuel injection valve that injects fuel into the first intake port, and an ignition plug provided at a location at which the gas flowing into the cylinder from the second intake port impinges on the ignition plug in a larger quantity than the gas flowing into the cylinder from the second intake port during the intake stroke.

Abstract: Provided is an internal combustion engine including a sparkplug disposed in the vicinity of the center portion of an upper wall surface of a combustion chamber. Tumble flow generated during lean burn operation is controlled such that the tumble flow shape changes according to the engine rotation speed between a first tumble shape (usual tumble shape) in which the flow direction of a gas around the sparkplug at the time of ignition is direction from an intake valve side toward an exhaust valve side in a latter half of a compression stroke, and a second tumble shape (? tumble shape) in which the flow direction of the gas is reversed in the latter half of the compression stroke from the direction from the intake valve side toward the exhaust valve side to the direction from the exhaust valve side toward the intake valve side.

Abstract: A control system for a spark-ignition internal combustion engine configured to produce tumble flow in a cylinder is provided. The spark-ignition internal combustion engine includes an ignition plug configured to ignite an air-fuel mixture in the cylinder. The control system includes a tumble flow rate controller configured to change a position of a vortex center of the tumble flow as viewed in a direction of a center axis of the cylinder, so as to control a flow rate of the tumble flow around the ignition plug at the ignition timing of the ignition plug.

Abstract: A control system for a spark-ignition internal combustion engine configured to produce tumble flow in a cylinder is provided. The spark-ignition internal combustion engine includes an ignition plug configured to ignite an air-fuel mixture in the cylinder. The control system includes a tumble flow rate controller configured to change a position of a vortex center of the tumble flow as viewed in a direction of a center axis of the cylinder, so as to control a flow rate of the tumble flow around the ignition plug at the ignition timing of the ignition plug.

Abstract: An internal combustion engine where a tumble flow is generated inside a combustion chamber includes: a spark plug; an in-cylinder injection valve that injects fuel at a specific timing so that a fuel spray proceeds towards the vortex center of the tumble flow at the time of stratified charge combustion operation; a variable tumble flow device for making the strength of a tumble flow variable; and a control device configured, when the spray penetration force of fuel injected by the in-cylinder injection valve is increased due to a change over time of the internal combustion engine, to close the variable tumble flow device during the stratified charge combustion operation.

Abstract: An internal combustion engine where a tumble flow is generated inside a combustion chamber includes: a spark plug; an in-cylinder injection valve that injects fuel at a specific timing so that a fuel spray proceeds towards the vortex center of the tumble flow at the time of stratified charge combustion operation; and a control device that, in a case where the size of a combustion fluctuation during the stratified charge combustion operation is greater than a determination value, changes an in-cylinder injection ratio so that a plug-periphery air-fuel ratio becomes richer. The changing of the ratio is performed by, first, decreasing the ratio by a fixed amount, and when the plug-periphery air-fuel ratio becomes richer as a result thereof, continuing to decrease the ratio, while when the aforementioned result is that the plug-periphery air-fuel ratio becomes leaner, increasing the ratio.

Abstract: An internal combustion engine includes an ignition plug and an electronic control unit. The electronic control unit is configured to: (i) execute a lean-burn operation in a first operation region, (ii) execute an operation in a second operation region at an air-fuel ratio lower than an air-fuel ratio during the lean-burn operation, and (iii) control a gas flow in a cylinder so that a ratio of a change in a gas flow speed around the ignition plug during ignition to a change in an engine rotation speed in a first engine rotation speed region within the first operation region is smaller than the ratio in a second engine rotation speed region within the second operation region.

Abstract: Provided is an internal combustion engine including a sparkplug disposed in the vicinity of the center portion of an upper wall surface of a combustion chamber. Tumble flow generated during lean burn operation is controlled such that the tumble flow shape changes according to the engine rotation speed between a first tumble shape (usual tumble shape) in which the flow direction of a gas around the sparkplug at the time of ignition is direction from an intake valve side toward an exhaust valve side in a latter half of a compression stroke, and a second tumble shape (? tumble shape) in which the flow direction of the gas is reversed in the latter half of the compression stroke from the direction from the intake valve side toward the exhaust valve side to the direction from the exhaust valve side toward the intake valve side.

Abstract: An ignition control apparatus for an internal combustion engine of the present invention includes a spark plug (34) for igniting an air-fuel mixture in a cylinder, and is configured to be capable of measuring a discharge voltage and a discharge current of the spark plug (34). The ignition control apparatus determines the flow velocity of an in-cylinder gas based on a discharge energy integration value that is obtained by integrating a product of the discharge voltage and the discharge current over a predetermined period.

Abstract: A control apparatus for an internal combustion engine according to the present invention includes a spark plug (30) for igniting an air-fuel mixture in a cylinder, and is configured to be capable of measuring a discharge voltage of the spark plug (30). The control apparatus calculates a turbulence intensity index value that indicates the turbulence intensity of in-cylinder gas based on a predetermined frequency component extracted from a discharge voltage during at least a part of a discharge duration leading up to ignition and, in accordance with the turbulence intensity index value, adjusts the ignition energy that is supplied to the spark plug (30) during a combustion duration in a cycle in which the turbulence intensity index value is calculated.