205 results about "Pilot injection" patented technology

In fuel injector including an accumulator and an intensifier, fuel is injected such that an injection control valve and a piston control valve are individually controlled, an operational phase difference therebetween is regulated, and at least one of a maximum injection pressure, a rate of increase of an injection pressure at the start of an increase of pressure, a rate of decrease of the injection pressure at the completion of injection, a pilot injection pressure, and an after injection pressure of fuel injected from a fuel injection nozzle is arbitrarily changed. Namely, a pressure during a movement from a base common rail pressure of the accumulator to a static maximum pressure statically determined by an operation of the intensifier is positively used as a control factor of injection, whereby a fuel injection pattern can be implemented with an extremely high degree of freedom.

What is disclosed is a micro-pilot injection ignition type gas engine, whereby an air fuel ratio control in starting the engine is executed with enhanced precision, by means of introducing skip-firing intermittent operations which reflect the engine operation conditions, while an idling time span can be shortened or omitted.

The engine includes: a gas valve that opens and closes a fuel-gas passage in front of each cylinder, so as to arbitrarily control the throat area as well as the opening-closing time span of the gas valve; an engine speed detecting unit to detect the engine speed; a combustion diagnosis unit to detect an engine combustion state through a cylinder pressure distribution along elapsed time, as to each cylinder; an opening-closing control unit as to the gas valve, so as to control the intermittent opening-closing of the gas valve according to the levels of the detected engine speed as well as the cylinder pressure distribution; whereby, in starting the engine, the intermittent opening-closing of the gas-valve enables at least one skip-firing mode that brings an enhanced fuel-supply pressure-pulsation with which a relatively large amount of fuel-gas is supplied per engine cycle with firing so that the air fuel-gas ratio of each cylinder reaches a prescribed target value.

A compression ignition engine is supplied with a first fuel in a flow of air and a second fuel is injected into the combustion chamber. The first fuel comprises a more volatile fuel than diesel such as ethanol, LPG or other combustible gas; the second fuel comprises diesel or biodiesel; and the second fuel is injected in multiple pulses in each ignition cycle with the first pulse acting as a pilot pulse to trigger ignition, and the timing of the second pulse being such as to modify the temperature through evaporation of the second fuel and thereby reduce the combustion temperature and mitigate knock susceptibility. Preferably the pilot pulse is followed by a single further pulse of the second fuel in the ignition cycle. The engine may be controlled to operate in two different modes, one mode for light and medium load conditions when there is only a pilot pulse injection of the second fuel which reduces NO_x and soot emissions, and the other mode for higher load conditions when there is a pilot pulse injection followed by a main pulse injection of the second fuel. The first fuel may comprise bioethanol and or one or more of the following: ethanol, butanol, propanol, lpg, natural gas, hydrogen.

In one embodiment, a total pilot injection amount is calculated from the difference between a compressed gas temperature in a cylinder and a fuel self-ignition temperature. As pilot injection, a plurality of instances of divided pilot injection are performed, and by setting the injection amount per one instance of divided pilot injection to an injector minimum limit injection amount, each divided pilot injection amount is suppressed, and the penetration of fuel is suppressed to a low level so that attachment of fuel to a wall face is avoided, and also, fuel is caused to accumulate in the center portion of the cylinder.

This system for controlling the combustion noise of a motor vehicle diesel engine of the type including means for feeding each of its cylinders with fuel by multiple injections of fuel, which means are adapted to trigger fuel feed into each cylinder in the form of at least one pilot injection and a main injection of fuel, comprises: means for determining pressure gradients in the engine cylinder while in operation, at least during the pilot and main injection stages; and means for determining the quantity of fuel to be injected into the cylinder during pilot injection for a predetermined quantity of fuel injected during main injection so as to optimize a criterion based on the ratio between the pressure gradients corresponding to the pilot and main injection stages, thereby optimizing the operating noise of the engine.

An internal combustion engine control device includes a NOx adsorber catalyst disposed in an exhaust passage, an EGR passage, a reducing agent adding device, a torque fluctuation reducing device, and a fuel injection device. The EGR passage draws a portion of exhaust gas from the exhaust passage downstream of the NOx adsorber catalyst and recirculates the exhaust gas into the intake passage. The reducing agent adding device adds a reducing agent to exhaust gas upstream of the NOx adsorber catalyst to reduce substances adsorbed by the NOx adsorber catalyst. When or after the reducing agent adding device adds the reducing agent, the torque fluctuation reducing device advances the timing of the fuel injection device or carries out a pilot injection to reduce a fluctuation in engine torque. The reducing agent adding device adds less reducing agent while the torque fluctuation reducing device is operating.

The invention relates to an oil control system of a diesel/natural gas dual-fuel internal combustion engine. The oil control system of the diesel/natural gas dual-fuel internal combustion engine can effectively solve the problem that control accuracy and refit effects are poor. According to the structure of the oil control system of the diesel/natural gas dual-fuel internal combustion engine, a microcontroller is connected with a programmable logic controller, a sensor is respectively connected with the input end of the microcontroller and the input end of the programmable logic controller, the output end of the microcontroller is connected with a switching circuit, the output end of the programmable logic controller is connected to an actuator, the switching circuit is respectively connected with diesel ECU driving signals, artificial loads and an oil atomizer, the oil atomizer is connected with the actuator and a sampling instrument, the sampling instrument is connected with a comparator, the comparator is connected to the programmable logic controller, and the artificial loads are connected with the sensor through a detector for detecting fuel injection pulse width. The oil control system of the diesel/natural gas dual-fuel internal combustion engine is simple, novel and unique in structure, and accurate and reliable in control, is effectively applied to dual-fuel diesel high pressure common rails, electronic controlled monoblock pumps and pump nozzle engines, can completely avoid influences of pilot injection, post injection and other multiple times oil injection signals of an original vehicle under a duel-fuel mode, reduces oil consumption of the system, and improves the substitution rate.

A crankshaft of an internal combustion engine is connected to an automatic transmission mechanism through a torque converter. A difference in a load applied to the crankshaft between a D range and a P range is sensed based on a difference in a command fuel injection amount during idling stabilization control between the D range and the P range. A difference between a fuel amount required by learning control of pilot fuel injection in the D range and a standard command fuel injection amount required for performing the learning control under the load corresponding to the p range is reduced by a fuel injection amount difference caused by the difference of the load. A learning value of the pilot injection is learned based on the reduced difference.

In a method for operating a spark-ignition internal combustion engine with direct fuel injection in the post-start phase at low temperatures, fuel is supplied to the combustion air in a pilot injection (M_H) of a first fuel quantity during an intake stroke of the internal combustion engine such that the pilot injection (M_H) forms a homogeneous, lean air/fuel mixture (λ>1) in substantially the entire combustion chamber, and a main injection (M_S) of a second fuel quantity is subsequently injected into the combustion chamber during a compression stroke directly before the ignition time (ZT), said main injection (M_S) forming in the region of the spark plug a stratified, rich air/fuel mixture (λ<1), which is then ignited by the spark plug.

The invention discloses a method for controlling diluent or lean mixed gas burning and ignition through high-flammability fuel micro ignition. The method comprises the steps that gasoline is ignited through spontaneous burning of a small amount of layered high-flammability fuel, and stable flame propagation is formed; the temperature inside a cylinder is increased through energy released by flame propagation and piston upward compression, meanwhile, multiple spontaneous burning points are formed in unburnt diluent or lean mixed gas under the assistance of a small amount of pilot injection high-flammability fuel, and then stable and rapid burning or multi-point spontaneous burning is formed. When an engine encounters knock or the largest explosion pressure exceeds limits, the burning process can be converted into rapid flame propagation type burning by introducing cooled burnt waste gas or excess air. When the heat state in the cylinder is not enough to form stable flame propagation or spontaneous burning heat release, the heat state in the cylinder is improved by introducing internal residual waste gas. The control problem in the ignition and burning process of premixed diluent or lean mixed gas can be solved.

In an electronic fuel injection apparatus comprising a control circuit of an electromagnetic spill valve for adjusting a fuel injection quantity in a distribution-type fuel injection pump for a diesel engine, and a computing unit for providing a command signal to the control circuit, a driving current flowing through a solenoid of an electromagnetic spill valve is detected, a state where a delay time interval from a transit point of a command signal provided to the control circuit to a delay point at which the driving current crosses a threshold value is equal to or more than a predetermined value is determined as a slightly abnormal state to invalidate the command signal for a pilot injection, or a state where the delay time interval exceeds an allowable value further larger than the predetermined value is determined as a seriously abnormal state to stop the engine.

Base station transmitter signals are combined more effectively through the use of anti-phase pilots between pairs of transmission paths. At the combiner, the pilots will cancel when the amplitude, phase, and delay of the two transmission paths entering the combiner are matched. As a result, the pilots will not appear at the output except when the alignment is incorrect. By detecting the residual pilot at the combiner output, the information is used to adjust the alignment of one of the transmission paths to match the other. The adjustments to the amplitude, phase, and delay are performed on the input signal, after the pilot injection.

A geometric compression ratio in an engine main body 1 is set to 15 or less. Injection control means (ECU 40) performs a main injection of injecting fuel near a compression top dead center, and a preceding injection prior to the main injection at a specific region of predetermined load within an operating region on a relatively low-speed side. The injection control means performs, as the preceding injection, a pilot injection of performing injection at a timing such that at least part of a fuel spray reaches outside a cavity 31 on a top face of a piston, and a pre-injection of injecting fuel at a predetermined timing after the pilot injection, to suppress thereby ignition of the fuel injected by the pilot injection and shorten an ignition delay of the fuel injected by the main injection.

Disclosed is a fuel injection amount compensating method that may include measuring a real pressure of a combustion chamber, calculating a real pressure level of the combustion chamber based on the real pressure, calculating a real combustion noise index based on the real pressure level of the combustion chamber, calculating a target combustion noise index based on a driving condition, calculating a difference between the real combustion noise index and the target combustion noise index, and increasing or reducing a pilot injection amount of a fuel injector in accordance with the difference. Also disclosed is a fuel injection amount compensating system.

A method of operating an internal combustion engine, wherein the engine is operated in an injector learning mode in which an injection parameter associated with a nominal fuel quantity of a pilot injection is learned, includes performing a learning pilot injection based on a candidate value for the injection parameter to influence injection of the nominal fuel quantity and determining a parameter indicative of the actually injected fuel quantity based on the in-cylinder pressure during combustion of the learning pilot injection. The learning pilot injection is operated at an early timing such that combustion thereof complete occurs within a learning window positioned before combustion TDC and before the next combustion starts. The pressure is measured over the learning window, so that the determination of the parameter indicative of the actually injected fuel quantity takes into account essentially the entire combustion event of the learning pilot injection.