A spark ignition type engine enabling engine startability to be favorable is provided. The spark ignition type engine includes a main intake-air passage; a throttle valve of the main intake-air passage; a bypass intake-air passage bypassing the throttle valve; an ISC valve of the bypass intake-air passage; and an electronic control device that controls an engine speed by adjusting an opening degree of the ISC valve, in which when the engine is started, cranking is performed at a cranking opening degree at which the ISC valve is narrowed by a predetermined amount from a fully opened state by control of the electronic control device, so that an intake-air negative pressure is generated on an intake-air downstream side of the ISC valve.

A variable valve timing assembly is provided for extending a duration of an intake valve opening. The variable valve timing assembly includes an intake rocker mounted on a pedestal and operable by a cam lobe to open and close the intake valve. The intake rocker includes a lever extension, and a holding member in the pedestal is lockable in position by a hydraulic circuit in the pedestal to contact the lever extension of the intake rocker and hold the intake valve in the open position. A reset pin in the pedestal is actuatable by the cam lobe to release the holding member to allow the intake valve to close.

A method for operating an internal combustion engine having a cylinder, an intake valve, an air pipe, and a valve element disposed in the air pipe, includes detecting a signal for causing a fuel supply of the cylinder to switch off. The valve element is moved out of a first position into a second position triggering a lower flow cross-section while the fuel supply is still activated, where a first cam for actuating the intake valve is allocated to the intake valve. While the fuel supply is still activated, switching from the first cam to a second cam and via the second cam the intake valve is actuated such that the intake valve causes a reduced air intake. An exhaust cam shaft for actuating an exhaust valve is set in an advance direction such that a valve intersection of the intake valve and of the exhaust valve ceases.

In certain embodiments, Lube Oil Controlled Ignition (LOCI) Engine Combustion overcomes the drawbacks of known combustion technologies. First, lubricating oil is already part of any combustion engine; hence, there is no need to carry a secondary fuel and to have to depend on an additional fuel system as in the case of dual-fuel technologies. Second, the ignition and the start of combustion rely on the controlled autoignition of the lubricating oil preventing the occurrence of abnormal combustion as experienced with the Spark Ignition technology. Third, LOCI combustion is characterized by the traveling of a premixed flame; hence, it has a controllable duration resulting in a wide engine load-speed window unlike the Homogeneous Charge Compression Ignition technology where the engine load-speed window is narrow. Adaptive Intake Valve Closure may be used to control in-cylinder compression temperature to be high enough to realize the consistent auto ignition of the lubricating oil mist.

The present invention relates to a method for increased exhaust gas temperature and emission reduction at partial loads in a diesel engine, wherein said engine comprises a cylinder with a reciprocating piston, a variable compression volume (VCR), and at least one exhaust valve and at least one inlet valve, the latter being equipped with variable valve timing (WT). According to the prevailing engine power requirement, an engine control system determines when to open and close said inlet valve, and the size of said compression volume in order to achieve a sufficiently elevated exhaust gas temperature so that correct exhaust gas purification can be achieved. The method is characterized in that the cylinder pressure during the expansion stroke is managed by the engine control system by means of the VCR and VVT functions, such that said pressure reaches atmospheric or sub atmospheric levels at or before bottom dead centre, at engine loads at or below 25% of the maximum engine load, whereby the inlet valve is opened to allow air to mix with the combustion gases. The invention also relates to a corresponding device and a diesel engine comprising said device.

Due to changes in a flow of an air-fuel mixture in a cylinder, reliable ignition due to spark discharge may not be possible. Therefore, an ignition control unit 24 includes a secondary voltage calculation unit 31 that calculates an average value of a secondary voltage generated on a secondary side of an ignition coil, an irregular flow ratio calculation unit 32 that calculates a ratio of cycles in which the average value of the secondary voltage is equal to or less than a set average value with respect to a cycle of the internal combustion engine in a predetermined period as an irregular flow ratio indicating that the flow of the air-fuel mixture in the cylinder is irregular, and an ignition operation amount correction unit 37 that corrects an ignition operation amount so that the irregular flow ratio is equal to or less than the set ratio value that is the target to be reached of the irregular flow ratio.

An internal combustion engine with an open-loop or closed-loop control device (2), wherein at least one combustion chamber (3) of the internal combustion engine (1) is designed to burn a fuel-air mixture using at least one combustion parameters that can be influenced by the open-loop or closed-loop control device (2), wherein the open-loop or closed-loop control device (2) has an emission control loop that is configured to actuate the at least one actuator that influences the at least one combustion parameter as a substitute parameter for NOx emissions by means of a functional relationship in such way that at last one combustion parameter can be set for each target or actual power rating of the internal combustion engine (1), wherein the functional relationship takes account of an influence of a change of the exhaust backpressure (p.sub.3’) affecting at least one combustion chamber (3).

A control system for controlling operation of an internal combustion engine is configured to: receive a first request signal indicative of first torque demand; determine a schedule defining an opening timing of the intake valve and a closing timing of the intake valve of a cylinder of the internal combustion engine in dependence on the first torque demand; and cause the intake valve to open in accordance with the schedule. The control system is also configured to, during a period in which the intake valve is open: receive a second torque request signal indicative of a second torque demand different to the first torque demand; determine an updated schedule defining an updated closing timing of the intake valve in dependence on the second torque demand; and cause the intake valve to close in accordance with the updated schedule.

An engine controlling method is provided, which includes, during motoring of the engine, outputting, by an in-cylinder pressure sensor, to a controller a signal indicative of a reference pressure corresponding to a pressure change after an intake valve of a cylinder of the engine is closed when not performing fuel injection, and then injecting, by an injector, fuel for analysis into the cylinder at a specific timing after the intake valve is closed. The method includes, by the controller, acquiring a crank angle period from the intake valve close timing, through the fuel injection, to a timing of the in-cylinder pressure reaching the reference pressure based on signals from the in-cylinder pressure sensor and a crank angle sensor, and determining a property of the injected fuel by comparing the acquired crank angle period with that of a standard fuel based on stored information on a property of the standard fuel.

The invention relates to an internal combustion engine comprising a crankshaft, one or more cylinders including a cylinder head, a piston, a combustion chamber, one or more intake valves, one or more exhaust valves, an intake system configured for feeding intake air to the engine, an exhaust system configured for conveying exhaust gas away from the engine, a pressure charging system connected to the intake system and an exhaust gas recirculation (EGR) system arranged to feed branched off exhaust gas from the exhaust system to the intake system via an EGR conduit wherein: * the internal combustion engine includes a valve actuation device configured to allow for late or early closing of the intake valves in accordance with late or early Miller-type valve timing, and wherein * the EGR system includes a gas feeding device configured to feed exhaust gas through the EGR conduit in modes of operation wherein the pressure in the intake system exceeds the pressure in the exhaust system, * wherein the gas feeding device is a displacement pump and wherein the gas feeding device is arranged so that exhaust gas recirculating in the EGR system during operation of the engine passes the gas feeding device before being mixed with intake air in the intake system. Additionally, a method of improving efficiency of an internal combustion engine is described.