Abstract: A fuel injection device includes a fuel injection valve at a position corresponding to a portion between intake ports in an internal combustion engine. The fuel injection valve includes a body and a needle inside the body. The fuel injection valve is disposed closer to a piston of the internal combustion engine than the intake ports are to the piston. A single fuel injection passage for conducting gaseous fuel is present between a valve seat of the fuel injection valve and a combustion chamber of the internal combustion engine. The flow cross section of the gaseous fuel in the fuel injection passage is larger on a side closer to the piston of the internal combustion engine than on a side closer to an ignition plug of the internal combustion engine over a specified length in an extending direction of the fuel injection passage.

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 internal combustion engine includes: a main combustion chamber; an intake port connected to the main combustion chamber; an exhaust port connected to the main combustion chamber; a sub-chamber; and a spark plug in the sub-chamber. The sub-chamber is provided between the intake opening portion and the exhaust opening portion and connected to the main combustion chamber through a plurality of communication holes. The communication holes include a first communication hole provided on the intake opening portion side, and a second communication hole provided on the exhaust opening portion side. The first communication hole is closer to a piston than the second communication hole is. The first communication hole is inclined to be closer to the piston as the first communication hole is positioned toward the inside from the outside of the sub-chamber.

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: a main combustion chamber; an intake port connected to the main combustion chamber; an exhaust port connected to the main combustion chamber; a sub-chamber; and a spark plug in the sub-chamber. The sub-chamber is provided between the intake opening portion and the exhaust opening portion and connected to the main combustion chamber through a plurality of communication holes. The communication holes include a first communication hole provided on the intake opening portion side, and a second communication hole provided on the exhaust opening portion side. The first communication hole is closer to a piston than the second communication hole is. The first communication hole is inclined to be closer to the piston as the first communication hole is positioned toward the inside from the outside of the sub-chamber.

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: Where performing a main injection, and a sub-injection that injects a minute amount of fuel in a short region of driving time, a check is conducted to determine whether or not the minute amount of fuel is injected accurately. In a specific cycle at a time of cold starting when catalyst warm-up control is performed, the main injection is omitted and a checking injection corresponding to a sub-injection is performed. Injection conditions of an in-cylinder injection valve are made uniform between the checking injection and the sub-injection. A fuel amount that is actually injected from the in-cylinder injection valve in the specific cycle is calculated based on an air-fuel ratio of exhaust gas discharged from an engine and an in-cylinder air amount, and is compared with a fuel amount that theoretically should be injected from the in-cylinder injection valve.

Abstract: A control device for an internal combustion engine includes first and second intake ports (16a, 16b) independent of each other, and first and second fuel injection valves (30a, 30b) provided for the first and second intake ports (16a, 16b), respectively, in each cylinder. Under a situation where an exhaust variable valve mechanism (38) is controlled such that a first exhaust valve (32a) is opened earlier than a second exhaust valve (32b), first and second air-fuel ratios A/F1, A/F2 are respectively obtained in a first half and a second half of an exhaust stroke. When the obtained first air-fuel ratio A/F1 (or the second air-fuel ratio A/F2) is lean, a fuel injection amount in a next cycle by the first or second fuel injection valve (30a, 30b) corresponding to the first air-fuel ratio A/F1 (or the second air-fuel ratio A/F2) that is lean is reduced.

Abstract: Where performing a main injection, and a sub-injection that injects a minute amount of fuel in a short region of driving time, a check is conducted to determine whether or not the minute amount of fuel is injected accurately. In a specific cycle at a time of cold starting when catalyst warm-up control is performed, the main injection is omitted and a checking injection corresponding to a sub-injection is performed. Injection conditions of an in-cylinder injection valve are made uniform between the checking injection and the sub-injection. A fuel amount that is actually injected from the in-cylinder injection valve in the specific cycle is calculated based on an air-fuel ratio of exhaust gas discharged from an engine and an in-cylinder air amount, and is compared with a fuel amount that theoretically should be injected from the in-cylinder injection valve.

Abstract: Test liquid (3) including thermosetting resin is injected from an injection valve (2). Light (L) is irradiated to a spray (6) of the test liquid (3) injected from the injection valve (2) as a treatment for producing a hardening effect to the thermosetting resin. Liquid drops in the spray (6) are hardened and collected as particles. Spray characteristics such as a particle size distribution of the injection valve or the like are analyzed by using the collected particles.

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 device is applied to an engine configured to generate one or more discharges within an ignition period. Regarding the device, a discharge voltage within first period or an amount of fuel included in the gas is referred to as a first parameter, which first period is from a discharge start timing to an intermediate timing after and near the discharge start timing, a discharge voltage within second period or a flow rate of the gas near the discharge is referred to as a second parameter, which second period is from the intermediate timing to a discharge end timing, and it is determined whether to start another discharge following the discharge within the ignition period based on at least the second parameter among the first and second parameters. Furthermore, the another discharge is started with an ignition unit when being determined to start the another discharge.

Abstract: Test liquid (3) including thermosetting resin is injected from an injection valve (2). Light (L) is irradiated to a spray (6) of the test liquid (3) injected from the injection valve (2) as a treatment for producing a hardening effect to the thermosetting resin. Liquid drops in the spray (6) are hardened and collected as particles. Spray characteristics such as a particle size distribution of the injection valve or the like are analyzed by using the collected particles.

Abstract: An internal combustion engine can form, in a combustion chamber, a fuel-air mixture region located on the first intake port side and containing mainly a fuel-air mixture, and a burned gas region located on the second intake port side and containing burned gas. When the fuel-air mixture region and a burned gas region are formed, the internal combustion engine determines injection rates of a first fuel injection valve and a second fuel injection valve so that fuel is injected from the first fuel injection valve and second fuel injection valve respectively, depending on an EGR rate. The injection rates are determined such that the injection rate of the first fuel injection valve is increased in accordance with the rise of the EGR rate.

Abstract: A control device for an internal combustion engine includes first and second intake ports (16a, 16b) independent of each other, and first and second fuel injection valves (30a, 30b) provided for the first and second intake ports (16a, 16b), respectively, in each cylinder. Under a situation where an exhaust variable valve mechanism (38) is controlled such that a first exhaust valve (32a) is opened earlier than a second exhaust valve (32b), first and second air-fuel ratios A/F1, A/F2 are respectively obtained in a first half and a second half of an exhaust stroke. When the obtained first air-fuel ratio A/F1 (or the second air-fuel ratio A/F2) is lean, a fuel injection amount in a next cycle by the first or second fuel injection valve (30a, 30b) corresponding to the first air-fuel ratio A/F1 (or the second air-fuel ratio A/F2) that is lean is reduced.

Abstract: An ignition control device is applied to an engine configured to generate one or more discharges within an ignition period. Regarding the device, a discharge voltage within first period or an amount of fuel included in the gas is referred to as a first parameter, which first period is from a discharge start timing to an intermediate timing after and near the discharge start timing, a discharge voltage within second period or a flow rate of the gas near the discharge is referred to as a second parameter, which second period is from the intermediate timing to a discharge end timing, and it is determined whether to start another discharge following the discharge within the ignition period based on at least the second parameter among the first and second parameters. Furthermore, the another discharge is started with an ignition unit when being determined to start the another discharge.

Abstract: In a direct injection spark ignition internal combustion engine that includes a fuel injection valve, and closes an intake valve after gas in the combustion chamber begins to flow back into an intake passageway after the compression stroke begins. The required fuel injection amount is injected a first fuel injection and a second fuel injection in a single combustion cycle, and the first fuel injection is performed while the intake valve is open during the compression stroke, and the second fuel injection is performed after the intake valve closes. The timing of the first fuel injection is set such that the injected fuel is deflected upwards in the top of the combustion chamber by the gas flowing toward the intake valve.

Abstract: Test liquid (3) including thermosetting resin is injected from an injection valve (2). Light (L) is irradiated to a spray (6) of the test liquid (3) injected from the injection valve (2) as a treatment for producing a hardening effect to the thermosetting resin. Liquid drops in the spray (6) are hardened and collected as particles. Spray characteristics such as a particle size distribution of the injection valve or the like are analyzed by using the collected particles.