A method for engine drivability robustness includes: dividing, by an engine controller, an engine state into a starting condition, a stop condition, and a deceleration condition; dividing an injection mode index of a fuel injection into a suction compression injection of the starting condition, a suction split injection of the stop condition, and a suction compression split injection of the deceleration condition, respectively, depending on a low volatile fuel condition; and performing a variable indexing mode to prevent an engine off by applying a lambda control factor for a rich lambda control by an increase in fuel amount to the deceleration condition.

A variable flow valve assembly is disclosed, and includes a main body, a piston, a position sensor, a controller, a solenoid, and a cover. The main body defines a chamber, an inlet port, an outlet port, and a wall located between the inlet port and the outlet port. The wall defines a metering orifice for selectively allowing a medium to flow from the inlet port to the outlet port. The chamber of the main body includes a pressurized chamber. The piston is moveable within the chamber of the main body in a plurality of partially open positions to vary the amount of medium flowing through the modulation orifice. The piston separates the pressurized chamber from the inlet port. The position sensor determines the position of the piston within the chamber of the main body, and the controller is in signal communication with the position sensor.

A variable flow valve assembly is disclosed, and includes a main body, a piston, a position sensor, a controller, a solenoid, and a cover. The main body defines a chamber, an inlet port, an outlet port, and a wall located between the inlet port and the outlet port. The wall defines a metering orifice for selectively allowing a medium to flow from the inlet port to the outlet port. The chamber of the main body includes a pressurized chamber. The piston is moveable within the chamber of the main body in a plurality of partially open positions to vary the amount of medium flowing through the modulation orifice. The piston separates the pressurized chamber from the inlet port. The position sensor determines the position of the piston within the chamber of the main body, and the controller is in signal communication with the position sensor.

A gas mixer for mixing gaseous fuel and air for an internal combustion engine is disclosed. The gas mixer may have a housing defining an air path for mixing the gaseous fuel and the air within the air path. The housing may have a narrowed portion. The gas mixer may also have a displacement body axially displaceable and coaxially arranged within the air path. The displacement body and the housing may define an air passage disposed at the narrowed portion. The gas mixer may further have a fuel inlet fluidly connected to the air passage. The fuel inlet may be configured to supply gaseous fuel to the air passage. Further, the gas mixer may have an adjusting unit disposed at least partially within the air path. The adjusting unit may be connected to the displacement body and may be configured to axially displace the displacement body.

A composite intake system and method of operating a rotary engine with variable intake manifold is provided. The system includes two switching valves in a secondary intake switching tube to change the intake method. When the rotary engine works under low speed conditions, it adopts the long intake manifold and the side-intake mode. When the rotary engine works under medium and high speed conditions, it uses the short intake manifold and the composite-intake mode. When the rotary engine works under ultra high speed conditions, it takes the short intake manifold and the peripheral-intake mode.

A composite intake system and method of operating a rotary engine with variable intake manifold is provided. The system includes two switching valves in a secondary intake switching tube to change the intake method. When the rotary engine works under low speed conditions, it adopts the long intake manifold and the side-intake mode. When the rotary engine works under medium and high speed conditions, it uses the short intake manifold and the composite-intake mode. When the rotary engine works under ultra high speed conditions, it takes the short intake manifold and the peripheral-intake mode.

A multiple throttle device 100 includes: a throttle body 12 having a plurality of intake passages 10; a plurality of throttle valves 20; a plurality of secondary passages 102 respectively bypassing the plurality of throttle valves 20; and an air amount adjustment valve 30 for adjusting an amount of air flowing through the plurality of secondary passages 102. The air amount adjustment valve 30 includes a valve plug 40, and a guide part 50 for guiding the valve plug 40 in the axial direction. Opening into the inner peripheral surface 51 of the guide part 50 are: a plurality of first communication holes 52 respectively communicating with downstream sides of the throttle valves 20 in the plurality of intake passages 10; and a second communication hole 54 communicating with a canister 9 for collecting fuel vapor. The actuator 60 adjusts a position of the valve plug 40 in the axial direction such that a first effective opening area of each of the first communication holes 52 which is not blocked by the valve plug 40 and a second effective opening area of the second communication hole 54 which is not blocked by the valve plug 40 change.

A multiple throttle device 100 includes: a throttle body 12 having a plurality of intake passages 10; a plurality of throttle valves 20; a plurality of secondary passages 102 respectively bypassing the plurality of throttle valves 20; and an air amount adjustment valve 30 for adjusting an amount of air flowing through the plurality of secondary passages 102. The air amount adjustment valve 30 includes a valve plug 40, and a guide part 50 for guiding the valve plug 40 in the axial direction. Opening into the inner peripheral surface 51 of the guide part 50 are: a plurality of first communication holes 52 respectively communicating with downstream sides of the throttle valves 20 in the plurality of intake passages 10; and a second communication hole 54 communicating with a canister 9 for collecting fuel vapor. The actuator 60 adjusts a position of the valve plug 40 in the axial direction such that a first effective opening area of each of the first communication holes 52 which is not blocked by the valve plug 40 and a second effective opening area of the second communication hole 54 which is not blocked by the valve plug 40 change.

A method for engine drivability robustness includes: dividing, by an engine controller, an engine state into a starting condition, a stop condition, and a deceleration condition; dividing an injection mode index of a fuel injection into a suction compression injection of the starting condition, a suction split injection of the stop condition, and a suction compression split injection of the deceleration condition, respectively, depending on a low volatile fuel condition; and performing a variable indexing mode to prevent an engine off by applying a lambda control factor for a rich lambda control by an increase in fuel amount to the deceleration condition.

An exhaust gas pressure regulator for a combustion engine includes a regulator housing and an inner diffuser assembly arranged inside the regulator housing so that an exhaust gas flow duct is formed between an inner surface of the regulator housing and an outer surface of the inner diffuser assembly. The inner diffuser assembly includes a front portion and a regulating piston that is moveable relative to the front portion and the regulator housing between an idle position in which the exhaust gas flow duct is open, and a pressurized position in which the regulating piston at least partly closes the exhaust gas flow duct. The inner diffuser assembly includes at least one throttled flow passage between the gas flow duct and an exhaust gas pressure chamber defined by the regulating piston and an interior surface of the front portion.