Abstract: A control device for an internal combustion engine keeping down an increase in combustion noise at the time of a cold state, provided with a combustion control part successively performing at least pre-fuel injection, first main fuel injection, and second main fuel injection to perform premix charged compressive ignition so that heat is generated inside the combustion chamber in stages a plurality of times, the combustion control part comprising a target value setting part setting target injection amounts and target injection timings of the pre-fuel injection, first main fuel injection, and second main fuel injection and a correction part performing correction to make the target injection amount of the pre-fuel injection increase and make the target injection amount of the second main injection decrease when the temperature of the engine body or the temperature of a parameter with a correlative relationship with the temperature of the engine body becomes a predetermined temperature or less.

Abstract: A control device for an internal combustion engine includes an electronic control unit. The electronic control unit controls a fuel injection valve to inject at least primary fuel and secondary fuel in this order such that a pattern of a pressure increase rate in the combustion chamber includes a first peak and a second peak, controls an injection timing and an injection amount of each of the primary fuel and the secondary fuel such that a second peak value becomes higher than a first peak value, controls an intake device such that oxygen density is increased along with an increase in a load, and controls the injection timing and the injection amount of each of the primary fuel and the secondary fuel such that a peak difference acquired by subtracting the first peak value from the second peak value is increased as the load is increased.

Abstract: A control device for an internal combustion engine keeping down an increase in combustion noise at the time of a cold state, provided with a combustion control part successively performing at least pre-fuel injection, first main fuel injection, and second main fuel injection to perform premix charged compressive ignition so that heat is generated inside the combustion chamber in stages a plurality of times, the combustion control part comprising a target value setting part setting target injection amounts and target injection timings of the pre-fuel injection, first main fuel injection, and second main fuel injection and a correction part performing correction to make the target injection amount of the pre-fuel injection increase and make the target injection amount of the second main injection decrease when the temperature of the engine body or the temperature of a parameter with a correlative relationship with the temperature of the engine body becomes a predetermined temperature or less.

Abstract: A control device for an internal combustion engine includes an electronic control unit. The electronic control unit controls a fuel injection valve to inject at least primary fuel and secondary fuel in this order such that a pattern of a pressure increase rate in the combustion chamber includes a first peak and a second peak, controls an injection timing and an injection amount of each of the primary fuel and the secondary fuel such that a second peak value becomes higher than a first peak value, controls an intake device such that oxygen density is increased along with an increase in a load, and controls the injection timing and the injection amount of each of the primary fuel and the secondary fuel such that a peak difference acquired by subtracting the first peak value from the second peak value is increased as the load is increased.

Abstract: A fuel injection control apparatus of a compression ignition type internal combustion engine includes a controller adapted to control an injector so that pre-stage injection and post-stage injection are performed as fuel injection during one cycle. The controller controls an interval between the timing of the pre-stage injection and the timing of the post-stage injection so that an interval ?t1 between the timing of the pre-stage peak and the timing of the post-stage peak approximately satisfies a condition. The condition is that the interval ?t1 is 0.5 times an inverse number of the frequency f0 at which a combustion noise level becomes the maximum.

Abstract: A fuel injection device is provided with a fuel injection valve to inject fuel into a combustion chamber of an engine, and an electronic control unit to operate the fuel injection valve to inject the fuel in multiple separate injections. The electronic control unit controls a timing of a first fuel injection by the fuel injection valve to carry out the first fuel injection on the retard side with respect to a timing when a premix duration immediately after the first fuel injection is minimum, and controls a timing of a second fuel injection by the fuel injection valve in such a manner that a heat release rate waveform produced by the first fuel injection and the second fuel injection carried out thereafter has a double-peaked shape.

Abstract: For providing a combustion control device capable of decreasing unburned HC caused by a fuel attaching to a bore wall of a cylinder and unburned HC/CO produced by excessive diffusion of the fuel in premixed charge compression ignition combustion, an injector control unit controls an injector so as to start an initial fuel injection when a crank angle corresponds to an initial fuel injection start time when a piston arrives at such a position that the fuel injected from the injector reaches a lip but falls short of reaching a bore wall face of a cylinder, and terminate a final injection when the crank angle corresponds to a final fuel injection end time, when the piston arrives at such a position that the fuel injected from the injector reaches the lip but falls short of reaching a region below the lip in a cavity.

Abstract: A fuel injection control apparatus of a compression ignition type internal combustion engine includes a controller adapted to control an injector so that pre-stage injection and post-stage injection are performed as fuel injection during one cycle. The controller controls an interval between the timing of the pre-stage injection and the timing of the post-stage injection so that an interval ?t1 between the timing of the pre-stage peak and the timing of the post-stage peak approximately satisfies a condition. The condition is that the interval ?t1 is 0.5 times an inverse number of the frequency f0 at which a combustion noise level becomes the maximum.

Abstract: An internal combustion engine, in which intake air flows through an intake passage into a combustion chamber and exhaust gas resulting from the combustion in the combustion chamber flows through an exhaust passage, includes an exhaust gas purifier provided in the exhaust passage and having an oxidation catalyst, an LPL-EGR passage connecting between the intake passage and the exhaust passage at a position downstream of the exhaust gas purifier as seen in exhaust gas flow direction, a first estimating device for estimating exhaust gas composition at a position upstream of the exhaust gas purifier, a second estimating device for estimating exhaust gas composition at a position downstream of the exhaust gas purifier, a cylinder temperature adjusting device for adjusting temperature in the combustion chamber, and a controller for controlling the cylinder temperature adjusting device based on the difference in the exhaust gas composition between the first and second estimating devices.

Abstract: A fuel injection device is provided with a fuel injection valve to inject fuel into a combustion chamber of an engine, and an electronic control unit to operate the fuel injection valve to inject the fuel in multiple separate injections. The electronic control unit controls a timing of a first fuel injection by the fuel injection valve to carry out the first fuel injection on the retard side with respect to a timing when a premix duration immediately after the first fuel injection is minimum, and controls a timing of a second fuel injection by the fuel injection valve in such a manner that a heat release rate waveform produced by the first fuel injection and the second fuel injection carried out thereafter has a double-peaked shape.

Abstract: A controller sets a negative valve overlap period, during which both of an intake valve and an exhaust valve are closed, such that not all the burned gas is discharged from the combustion chamber. When switching the combustion mode from the spark ignition combustion to the HCCI combustion, the controller executes following operations a), b), and c): a): switching the intake lift amount from a first intake lift amount to a second intake lift amount, such that intake opening timing is delayed relative to an exhaust top dead center; b): switching the exhaust lift amount from a first exhaust lift amount to a second exhaust lift amount after the operation a); and c) delaying the exhaust closing timing relative to a reference exhaust closing timing, such that the internal EGR amount is generated.

Abstract: For providing a combustion control device capable of decreasing unburned HC caused by a fuel attaching to a bore wall of a cylinder and unburned HC/CO produced by excessive diffusion of the fuel in premixed charge compression ignition combustion, an injector control unit controls an injector so as to start an initial fuel injection when a crank angle corresponds to an initial fuel injection start time when a piston arrives at such a position that the fuel injected from the injector reaches a lip but falls short of reaching a bore wall face of a cylinder, and terminate a final injection when the crank angle corresponds to a final fuel injection end time, when the piston arrives at such a position that the fuel injected from the injector reaches the lip but falls short of reaching a region below the lip in a cavity.

Abstract: An internal combustion engine, in which intake air flows through an intake passage into a combustion chamber and exhaust gas resulting from the combustion in the combustion chamber flows through an exhaust passage, includes an exhaust gas purifier provided in the exhaust passage and having an oxidation catalyst, an LPL-EGR passage connecting between the intake passage and the exhaust passage at a position downstream of the exhaust gas purifier as seen in exhaust gas flow direction, a first estimating device for estimating exhaust gas composition at a position upstream of the exhaust gas purifier, a second estimating device for estimating exhaust gas composition at a position downstream of the exhaust gas purifier, a cylinder temperature adjusting device for adjusting temperature in the combustion chamber, and a controller for controlling the cylinder temperature adjusting device based on the difference in the exhaust gas composition between the first and second estimating devices.

Abstract: A premixed compression ignition type engine is operated while change over between spark ignition combustion and compression ignition combustion. This engine has a negative overlap period during steady operation under compression ignition combustion. In the same cylinder, a valve-closing timing of an exhaust valve during steady operation under spark ignition combustion is retarded with respect to the valve-closing timing thereof after the change over. In a case where an intake valve is first changed over after start of the change over from spark ignition combustion to compression ignition combustion, the valve-opening timing of the intake valve during a change over period from spark ignition combustion to compression ignition combustion is in an advanced state with respect to the valve-opening timing thereof during steady operation under spark ignition combustion.

Abstract: A failure diagnosis apparatus for a homogeneous charge compression ignition engine having combustion modes switchable between HCCI combustion, performed together with internal EGR, and SI combustion. The engine includes an intake variable valve mechanism and an exhaust variable valve mechanism. The apparatus includes an airflow meter detecting an intake amount of mixture drawn into a combustion chamber of the engine and a control computer determining whether a failure has occurred in the intake variable valve mechanism and the exhaust variable valve mechanism from intake amount change information.

Abstract: An intake passage (10) communicating with a combustion chamber (3) comprises a first branch intake passage (16) having an intake port (4) at one end thereof and also having an intake manifold including a surge tank (13), a second branch intake passage (17) having an intake port (14) at one end thereof and also having an intake manifold including a surge tank (23), and a common intake passage (19) communicating with the ends of the first branch intake passage (16) and the second branch intake passage (17). The common intake passage (19) is provided with a mixer (11) for producing a mixture. The intake passage (10) is provided with a switching valve (18) for bringing the common intake passage (19) into communication with at least one of the first branch intake passage (16) and the second branch intake passage (17).

Abstract: An HCCI engine provides a negative overlap period in an operation during HCCI combustion. During the negative overlap period, an intake valve and an exhaust valve are both closed when a piston is in the vicinity of the top dead center in an exhaust stroke, so that burned gas remains inside a combustion chamber. The engine is provided with a throttle, a fuel valve and an ECU. The ECU controls the throttle during a switching period in which SI combustion is switched to the HCCI combustion so that the opening degree of the throttle increases to the opening degree at the time of steady HCCI operation from the opening degree at the time of steady SI operation, and at the same time, controls the fuel valve such that the amount of fuel supplied to the intake passage becomes greater than the amount at the time of the steady SI operation.

Abstract: An HCCI engine operated in HCCI and SI combustion modes. The engine includes an external EGR apparatus for performing external EGR. A control unit executes combustion control by specifying either one of HCCI and SI combustion ranges based on the driving state of the engine and a combustion range map for specifying the combustion range in accordance with the driving state. The map includes the HCCI and SI combustion ranges and a switch preparation combustion range, which is included in the SI combustion range and extends along a boundary between the SI combustion range and the HCCI combustion range. The control unit lowers the temperature in the combustion chamber when the switch preparation combustion range is specified by reducing the amount of internal EGR or performing the external EGR.

Abstract: An HCCI engine capable of switching combustion mode between SI combustion and HCCI combustion is disclosed. At least one swirl port and at least one tumble port communicate with a combustion chamber of the HCCI engine. In a first switching period in which the SI combustion is switched to the HCCI combustion, intake air is supplied to the combustion chamber solely through the swirl port. In a second switching period in which the HCCI combustion is switched to the SI combustion, the intake air is supplied to the combustion chamber through at least the tumble port.

Abstract: At high temperature, namely, when the temperature of intake air is higher than a predetermined normal temperature range, an ECU (25) controls a variable valve timing mechanism (24) such that the timing for closing an exhaust valve (9) is adjusted to a retard side, thereby reducing the amount of high-temperature internal EGR gas to avoid the occurrence of pre-ignition. At intermediate load and high load, the ECU (25) makes the retard amount of the timing for closing the exhaust valve (9) larger than that at low load, thereby reducing the amount of internal EGR gas. At intermediate load and in an intermediate-revolution range or a high-revolution range, the rotating speed of an electric motor (16) is increased to raise a supercharging pressure exerted by a supercharger (17).