Abstract: A combustion chamber structure for an internal combustion engine includes a recessed portion formed in a pent roof of a cylinder head on an upstream side of a tumble flow with respect to a spark plug.

Abstract: A combustion chamber structure for an internal combustion engine includes a recessed portion formed in a pent roof of a cylinder head on an upstream side of a tumble flow with respect to a spark plug.

Abstract: In determining an in-cylinder pressure by analyzing a secondary current detected by a secondary current detection resistor, an engine controller is configured to detect an engine revolution speed and a discharge duration during which the secondary current flows. The discharge duration is correlated with a gas pressure between electrodes of a spark plug at ignition timing, that is, an in-cylinder pressure, and is different depending on the engine revolution speed. The engine controller is further configured to estimate the in-cylinder pressure at ignition timing based on the engine revolution speed and the discharge duration. An amount of time-dependent change in mechanical compression ratio, caused by accumulation of deposits, is detected based on the estimated in-cylinder pressure at ignition timing.

Abstract: An ignition device for an internal combustion engine (1) includes a superpose voltage generation circuit (47) that, after the initiation of a discharge with the application of a discharge voltage by a secondary coil, applies a superpose voltage between electrodes of an ignition plug (29) in the same direction as the discharge voltage to continue a discharge current, and performs a superposed discharge in a superposed discharge activation range of high exhaust recirculation rate. Upon shift from the superposed discharge activation range of high exhaust recirculation rate to a superposed discharge deactivation range of low exhaust recirculation rate, the deactivation of the superposed discharge is delayed by a delay time ?T. Although the exhaust gas recirculation rate becomes temporarily increased with decrease in intake air after the closing of an exhaust gas recirculation control valve, the superposed discharge is continued for the delay time ?T so as to avoid misfiring.

Abstract: When an operating condition including load and speed of an internal combustion engine is in a prescribed low-speed high-load region, i.e., an energy suppression region, having a possibility causing pre-ignition, energization time TDWLMIN for the energy suppression region is selected as a primary coil energization time. In other normal regions, normal energization time TDWL is selected. Normal energization time TDWL has a characteristic such that the normal energization time shortens, as the engine speed increases. In a low speed region, a given energization time that can fulfill a discharge energy required in a high exhaust gas recirculation region is provided. Energization time TDWLMIN for the energy suppression region is constant regardless of engine speeds and relatively short, and is set to a level such that a coil generated maximum voltage does not exceed a withstand voltage of a spark plug even when no-discharge occurs due to pre-ignition.

Abstract: In order to prevent an abnormal combustion due to oil, a restriction region (B) is designated on a low-speed and high-load side of an internal combustion engine (1), and an opening of throttle valve (12) is restricted so that an engine operating condition is not observed within the restriction region (B). A predetermined designated inspection region (A) is set so as to include the restriction region (B), and it is judged whether or not the abnormal combustion actually occurred when the internal combustion engine (1) is running within the designated inspection region (A). If the abnormal combustion was detected, the restriction region (B) is expanded, meanwhile, if the abnormal combustion was not detected, the expanded restriction region (B) is gradually decreased. If the abnormal combustion occurred at a shorter interval than a threshold value, the restriction region (B) is expanded at once to a predetermined size.

Abstract: In an ignition device of an internal combustion engine which carries out ignition of an air-fuel mixture by repeatedly applying a voltage across electrodes of an ignition plug thereby producing a plurality of discharges, an improvement is proposed in which in the presence of gas flow of which direction is perpendicular to a direction that connects the electrodes with a shortest distance, a time interval between n-th time discharge and (n?1)-th time discharge is so set that a discharge channel caused or proposed by the n-th time discharge is more extended in the gas flow direction than a discharge channel caused by the (n?1)-th time discharge.

Abstract: An ignition unit of an internal combustion engine is equipped with an ignition coil including a primary coil and a secondary coil, an igniter, and a secondary current detection resistor. By means of the secondary current detection resistor, an engine controller detects a current value of the secondary current immediately after completion of capacitive discharge. The current value of the secondary current is correlated with a gas pressure between electrodes of a spark plug at ignition timing, and thus an in-cylinder pressure at the ignition timing can be estimated from the current value. An amount of time-dependent change in compression ratio, caused by accumulation of deposits, is calculated based on the in-cylinder pressure at the ignition timing.

Abstract: An ignition device for an internal combustion engine (1) includes a superpose voltage generation circuit (47) that, after the initiation of a discharge with the application of a discharge voltage by a secondary coil, applies a superpose voltage between electrodes of an ignition plug (29) in the same direction as the discharge voltage to continue a discharge current, and performs a superposed discharge in a superposed discharge activation range of high exhaust recirculation rate. Upon shift from the superposed discharge activation range of high exhaust recirculation rate to a superposed discharge deactivation range of low exhaust recirculation rate, the deactivation of the superposed discharge is delayed by a delay time ?T. Although the exhaust gas recirculation rate becomes temporarily increased with decrease in intake air after the closing of an exhaust gas recirculation control valve, the superposed discharge is continued for the delay time ?T so as to avoid misfiring.

Abstract: An ignition unit (11) has a superimposed voltage generation circuit (17) that feeds, between electrodes of an ignition plug (9), a superimposed voltage of the same direction as a discharge voltage, and in an operation range wherein an engine rotation speed is equal to or lower than a given speed and an engine load is equal to or lower than a given load, feeding of the superimposed voltage is carried out. Although the energization time for a primary coil (15a) is basically set in accordance with the engine rotation speed, the energization time TDWLON for the superimposed voltage feeding is set shorter than the energization time TDWLOFF for the superimposed voltage non-feeding. With this, temperature increase of the ignition unit (11) caused by the feeding of the superimposed voltage is suppressed.

Abstract: In order to prevent an abnormal combustion due to oil, a restriction region (B) is designated on a low-speed and high-load side of an internal combustion engine (1), and an opening of throttle valve (12) is restricted so that an engine operating condition is not observed within the restriction region (B). A predetermined designated inspection region (A) is set so as to include the restriction region (B), and it is judged whether or not the abnormal combustion actually occurred when the internal combustion engine (1) is running within the designated inspection region (A). If the abnormal combustion was detected, the restriction region (B) is expanded, meanwhile, if the abnormal combustion was not detected, the expanded restriction region (B) is gradually decreased. If the abnormal combustion occurred at a shorter interval than a threshold value, the restriction region (B) is expanded at once to a predetermined size.

Abstract: When an operating condition including load and speed of an internal combustion engine is in a prescribed low-speed high-load region, i.e., an energy suppression region, having a possibility causing pre-ignition, energization time TDWLMIN for the energy suppression region is selected as a primary coil energization time. In other normal regions, normal energization time TDWL is selected. Normal energization time TDWL has a characteristic such that the normal energization time shortens, as the engine speed increases. In a low speed region, a given energization time that can fulfil a discharge energy required in a high exhaust gas recirculation region is provided. Energization time TDWLMIN for the energy suppression region is constant regardless of engine speeds and relatively short, and is set to a level such that a coil generated maximum voltage does not exceed a withstand voltage of a spark plug even when no-discharge occurs due to pre-ignition.

Abstract: An ignition unit (11) has a superimposed voltage generation circuit (17) that feeds, between electrodes of an ignition plug (9), a superimposed voltage of the same direction as a discharge voltage, and in an operation range wherein an engine rotation speed is equal to or lower than a given speed and an engine load is equal to or lower than a given load, feeding of the superimposed voltage is carried out. Although the energization time for a primary coil (15a) is basically set in accordance with the engine rotation speed, the energization time TDWLON for the superimposed voltage feeding is set shorter than the energization time TDWLOFF for the superimposed voltage non-feeding. With this, temperature increase of the ignition unit (11) caused by the feeding of the superimposed voltage is suppressed.

Abstract: An engine control apparatus has an electric discharge device, a voltage application device, a fuel supplying device, and a control unit. The electric discharge device includes a first electrode and a second electrode. The second electrode is arranged opposite the first electrode to produce radicals within a combustion chamber of an internal combustion engine by a non-equilibrium plasma discharge that is generated between the electrodes before autoignition of the air-fuel mixture occurs. The voltage application device is operatively coupled to the first electrode for applying a voltage between the first and second electrodes to generate the non-equilibrium plasma between the first and second electrodes. The fuel supplying device forms an air-fuel mixture inside the combustion chamber. The control unit is operatively coupled to the electric discharge device to set a discharge start timing of the electric discharge device to occur during an intake stroke of the internal combustion engine.

Abstract: In an ignition device of an internal combustion engine which carries out ignition of an air-fuel mixture by repeatedly applying a voltage across electrodes of an ignition plug thereby producing a plurality of discharges, an improvement is proposed in which in the presence of gas flow of which direction is perpendicular to a direction that connects the electrodes with a shortest distance, a time interval between n-th time discharge and (n?1)-th time discharge is so set that a discharge channel caused or proposed by the n-th time discharge is more extended in the gas flow direction than a discharge channel caused by the (n?1)-th time discharge.

Abstract: An internal combustion engine (100) comprises an intake valve (31) which opens and closes an intake port (30), a valve timing adjustment device (200) which adjusts a valve timing of the intake valve (31), a discharge portion (50) including a first electrode (51), a dielectric (53) covering the first electrode (51), a second electrode (52) disposed at a position facing the dielectric (53), and a discharge chamber (55) that is formed between the second electrode (52) and the dielectric (53) so as to face the combustion chamber (13), a voltage impressing mechanism (60) which impresses a voltage to the discharge portion (50) such that the radicals are produced in the discharge chamber (55) by a non-equilibrium plasma discharge, and a controller (70) which controls the valve timing control device (200) to close the intake valve (31) in an intake valve close period in which a piston lowers from an exhaust top dead center to an intake bottom dead center so as to diffuse the radicals in the discharge chamber (55) int

Abstract: An ignition device performs spark ignition to a fuel mixture in a combustion chamber (13) of an internal combustion engine (100, 101) by using a spark plug (50). The spark plug (50) includes a first electrode (51), a second electrode (52, 11a, 11b, 21), and an insulating member (53, 11c) which is formed from dielectric substance and interposed between the first electrode (51) and the second electrode (52, 11a, 21). By impressing an alternating current between the first electrode (51) and the second electrode (52, 11a, 21), non-equilibrium plasma discharge between the insulating member (53, 11c) and one of the first electrode (51) and the second electrode (52, 11a, 21) is promoted. Igniting the fuel mixture by the non-equilibrium plasma discharge achieves a high ignition performance is achieved with low energy consumption.

Abstract: An engine control apparatus has an electric discharge device, a voltage application device, a fuel supplying device, and a control unit. The electric discharge device includes a first electrode and a second electrode. The second electrode is arranged opposite the first electrode to produce radicals within a combustion chamber of an internal combustion engine by a non-equilibrium plasma discharge that is generated between the electrodes before autoignition of the air-fuel mixture occurs. The voltage application device is operatively coupled to the first electrode for applying a voltage between the first and second electrodes to generate the non-equilibrium plasma between the first and second electrodes. The fuel supplying device forms an air-fuel mixture inside the combustion chamber. The control unit is operatively coupled to the electric discharge device to set a discharge start timing of the electric discharge device to occur during an intake stroke of the internal combustion engine.

Abstract: An internal combustion engine electric discharge structure is provided which comprises a first electrode and a dielectric material. The first electrode includes a first voltage receiving end and a second engine attachment end with a long thin conductive material that discharges non-equilibrium plasma. The dielectric material covers the first electrode.

Abstract: An ignition device performs spark ignition to a fuel mixture in a combustion chamber (13) of an internal combustion engine (100, 101) by using a spark plug (50). The spark plug (50) comprises a first electrode (51), a second electrode (52, 11a, 11b, 21), and an insulating member (53, 11c) which is formed from dielectric substance and interposed between the first electrode (51) and the second electrode (52, 11a, 21). By impressing an alternating current between the first electrode (51) and the second electrode (52, 11a, 21), non-equilibrium plasma discharge between the insulating member (53, 11e) and one of the first electrode (51) and the second electrode (52, 11a, 21) is promoted. Igniting the fuel mixture by the non-equilibrium plasma discharge achieves a high ignition performance is achieved with low energy consumption.