In exemplary embodiments, methods and systems are provided for controlling emissions for a drive system for a vehicle. In one embodiment, the system includes: one or more first sensors configured to measure an engine temperature pertaining to an engine of the vehicle; one or more second sensors configured to measure an ambient temperature surrounding the vehicle; one or more third sensors configured to detect an amount of running time in which the engine has been running; and a processor coupled to the one or more first sensors, the one or more second sensors, and the one or more third sensors and configured to at least facilitate controlling emissions for the drive system based on the engine temperature, the ambient temperature, and the amount of running time in which the engine has been running.

An ignition device capable of more reliably protecting a primary winding of an ignition coil from high temperature is provided. The ignition device includes an ignition coil, a switching element, a temperature sensor, and a thermal cutout circuit. A primary winding of the ignition coil is connected to a DC power supply and the switching element. The temperature sensor is provided to measure the temperature of the switching element. The thermal cutout circuit forcibly turns off the switching element when the temperature of the switching element becomes higher than a predetermined forcible turn-off temperature Toff. The thermal cutout circuit is configured to lower the forcible turn-off temperature Toff when the power supply voltage Vb of the DC power supply decreases.

An apparatus for igniting a combustible mixture. In one example, the apparatus can include a coaxial cavity resonator assembly in a combustion environment. The apparatus can also include an operational feedback system and a controller. The operational feedback system can measure at least one of a voltage value and a current value of the coaxial cavity resonator assembly in the combustion environment. The controller can be configured to determine a condition of the coaxial cavity resonator assembly and modulate operation of the coaxial cavity resonator assembly based at least in part on the determined condition.

An ignition system has an ignition plug and an ignition control unit that controls the ignition plug. When an engine is in a predetermined operating state, the ignition control unit performs ignition control after top dead center to perform ignition after the compression top dead center. The ignition system has an airflow support structure that facilitates the flow of airflow through a discharge gap at least after the compression top dead center. The ignition system is configured such that due to the airflow support structure and the timing of the ignition, airflow at a flow rate of 5 m/s or more flows through the discharge gap during a spark period after top dead center, which is the generation period of the discharge spark in the ignition control after top dead center.

Systems and methods for starting and restarting an engine of a vehicle are disclosed. Power systems for an engine are disclosed.

An internal combustion engine includes an engine body defining a combustion chamber, an ignition device configured to ignite mixture in the combustion chamber, an operation device configured to receive a stop operation to stop the internal combustion engine, a controller configured to stop the ignition device from igniting the mixture in response to reception of the stop operation by the operation device, a carburetor configured to supply fuel to an intake passage that communicates with the combustion chamber, a switching valve provided in the intake passage, and an adjustment device configured to adjust an opening degree of the switching valve, wherein the adjustment device is configured to close the switching valve in conjunction with the reception of the stop operation by the operation device.

An internal combustion engine includes an engine body defining a combustion chamber, an ignition device configured to ignite mixture in the combustion chamber, an operation device configured to receive a stop operation to stop the internal combustion engine, a controller configured to stop the ignition device from igniting the mixture in response to reception of the stop operation by the operation device, a carburetor configured to supply fuel to an intake passage that communicates with the combustion chamber, a switching valve provided in the intake passage, and an adjustment device configured to adjust an opening degree of the switching valve, wherein the adjustment device is configured to close the switching valve in conjunction with the reception of the stop operation by the operation device.

Systems and methods are provided for cooling an overheated engine using a combination of variable displacement engine (VDE) technology and direct injection technology. In one example, a method may include deactivating a subset of engine cylinders based on an engine temperature and directly injecting liquid fuel into the deactivated cylinders. In this way, an increased thermal conductivity of the liquid fuel compared to air decreases the engine temperature at a faster rate than when air-based engine cooling methods are used, thereby preventing overheating-related engine degradation.

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 ignition circuit and a method of operating an igniter (preferably a traveling spark igniter) in an internal combustion engine, including a high pressure engine. A high voltage is applied to electrodes of the igniter, sufficient to cause breakdown to occur between the electrodes, resulting in a high current electrical discharge in the igniter, over a surface of an isolator between the electrodes, and formation of a plasma kernel in a fuel-air mixture adjacent said surface. Following breakdown, a sequence of one or more lower voltage and lower current pulses is applied to said electrodes, with a low “simmer” current being sustained through the plasma between pulses, preventing total plasma recombination and allowing the plasma kernel to move toward a free end of the electrodes with each pulse.