In a method for creating a spark across a spark gap, in particular for igniting a flammable liquid to measure its flash point, by means of a spark generator which comprises an ignition transformer, wherein the spark generator, on the primary side of the ignition transformer, comprises at least one DC voltage source and, on the secondary side of the ignition transformer, comprises two electrodes delimiting the spark gap to be formed, wherein voltage pulses from the DC voltage source are applied to the ignition transformer on the primary side thereof, which voltage pulses generate ignition voltage pulses on the secondary side, the ignition transformer is operated in a first phase according to the flyback converter principle and in a subsequent, second phase according to the forward converter principle.

Methods, systems, and devices for managing motor torque smoothing for internal combustion engine cylinder recharging events are described herein. An engine controller in a vehicle for managing motor torque smoothing for internal combustion engine cylinder recharging events may be configured to operate the internal combustion engine at a firing fraction that is less than a value of 1.0, wherein one or more cylinders are not designated to be fired, determine a recharge event time period where a particular one of the cylinders that have not been designated to be fired is recharged, identify a disruption quantity of torque during the recharging event time period, and actuate an additional motor to initiate a supplemental quantity of torque during the recharge event time period based on the disruption quantity of torque.

An engine control apparatus includes an ignition control section and an injection control section. When partial compression ignition combustion is carried out, the ignition control section causes an ignition plug to carry out: main ignition in which a spark is generated in a late period of a compression stroke or an initial period of an expansion stroke to initiate the SI combustion; and preceding ignition in which the spark is generated at earlier timing than the main ignition. Also, when the partial compression ignition combustion is carried out, the injection control section causes the injector to inject fuel at such timing that the fuel exists in a cylinder at an earlier time point than the preceding ignition. Energy of the preceding ignition is set to be higher when an engine speed is high than when the engine speed is low.

Methods and systems are provided for operating a variable displacement engine that includes a knock control system. Engine background noise levels for detecting engine knock may be the basis for determining whether or not the engine is operating in a cylinder deactivation mode. Further, select variable engine displacement modes may be avoided so that engine background noise level changes may be reduced to improve engine knock detection.

A spark plug includes a ground electrode, an insulator, and a center electrode. In a case where a first position of a surface of the ground electrode exposed to a side of an inner wall surface of a cylinder head is a most downstream position in an air flow direction between the center electrode and the ground electrode, and a second position of the inner wall surface of the cylinder head is a position closest to the center electrode on a downstream side of the center electrode in an air flow direction, the spark plug is installed at a position where the first position and the second position are on a same air flow line, or at a position where the first position is recessed to a side where the first position recedes from the inner wall surface than the second position.

Provided is an ignition system including: a main primary coil; a sub primary coil; a secondary coil; a control unit configured to: drive a main IC to switch a main primary coil mode from a de-energization mode to an energization mode; stop the drive of the main IC to switch the main primary coil mode from the energization mode to the de-energization mode; drive the sub IC to switch a sub primary coil mode from a de-energization mode to an energization mode; and stop the drive of the sub IC to switch the sub primary coil mode from the energization mode to the de-energization mode; and a detection circuit configured to detect a state of the secondary coil. The ignition system is configured such that the drive of the sub IC is stopped when the state of the secondary coil detected by the detection circuit is a no-current supply state.

An engine control apparatus includes an ignition control section and an injection control section. When the partial compression ignition combustion is carried out, the ignition control section causes an ignition plug to carry out: main ignition in which a spark is generated in a late period of a compression stroke or an initial period of a expansion stroke to initiate the SI combustion; and preceding ignition in which the spark is generated at earlier timing than the main ignition. Also, when the partial compression ignition combustion is carried out, the injection control section causes the injector to inject fuel at such timing that the fuel exists in a cylinder at an earlier time point than the preceding ignition. The energy of the preceding ignition is set to be higher when the in-cylinder pressure specified by the in-cylinder pressure specification section is high than when the in-cylinder pressure is low.

Methods, systems, and devices for managing motor torque smoothing for internal combustion engine cylinder recharging events are described herein. An engine controller in a vehicle for managing motor torque smoothing for internal combustion engine cylinder recharging events may be configured to operate the internal combustion engine at a firing fraction that is less than a value of 1.0, wherein one or more cylinders are not designated to be fired, determine a recharge event time period where a particular one of the cylinders that have not been designated to be fired is recharged, identify a disruption quantity of torque during the recharging event time period, and actuate an additional motor to initiate a supplemental quantity of torque during the recharge event time period based on the disruption quantity of torque.

An engine system provided to a vehicle having an accelerator pedal is provided. When an engine operation range is determined to shift to a first range (where an electromagnetic clutch is disengaged) from a second range (where the clutch is engaged) after an opening of the accelerator pedal increases at a rate below a given reference rate, the clutch is switched from ON to OFF after a given basic stand-by period passes from the shift. When the engine operation range is determined to shift from the second range to the first range after the accelerator pedal opening increases at the given reference rate or above, the clutch is switched from ON to OFF after a given acceleration stand-by period (longer than the basic stand-by period by a given added period) passes from the shift.

An internal combustion engine control device includes an ignition control unit which executes an ignition control for controlling an ignition plug which discharges electricity in a cylinder of an internal combustion engine to ignite fuel. The ignition control unit executes the ignition control such that a predetermined ignition electric energy is supplied to the ignition plug when the ignition plug performs ignition, and a predetermined pre-heating electric energy smaller than the ignition electric energy is supplied to the ignition plug before the ignition plug performs ignition.