摘要:
In a fuel injection pump, an engine drives a rotary plunger having an axially extending bore connected to a compression chamber, plural fuel inlet ports alignable with an inlet passage for introducing fuel to the compression chamber, fuel distribution ports for distributing the compressed fuel through the bore to each one of the fuel delivery passages and plural spill ports. A spill-port timing control unit is provided comprising a stator core, a coil wound on thereon, a magnetized ring having a spill groove, and a spring for resiliently maintaining the ring in a reference angular position with respect to the stator core. The magnetized ring is mounted on the plunger so that it can rotate from the reference angular position to an angularly displaced position in proportion to the magnetic flux of the coil to align the spill groove of the ring with each spill port of the plunger to create a passageway through which the compressed fuel is allowed to escape at the termination of fuel injection.
摘要:
Fuel injection pump of the type arranged to inject fuel into engine cylinders with the fuel flow being controlled by an electromagnetic valve, comprises a rotor arranged to rotate in timed relation to engine rotation, and a shuttle movably received in an axial bore made in the rotor. Opposite sides of the shuttle define first and second chambers within the axial bore, where the first chamber is used as a compression chamber to pressurize fuel introduced therein via the electromagnetic valve to inject the same into engine cylinders, and the second chamber is communicable with a low pressure fuel reservoir. Fuel is fed into the first and second chambers during an intake stroke or mode, and then the second chamber fuel is pressurized by means of an inner cam mechanism so that the shuttle moves toward the first chamber to pressurize the fuel therein, thereby injecting the fuel during a compression stroke. When the shuttle has been moved toward the first chamber beyond a predetermined position, the second chamber communicates with the low pressure fuel reservoir via a by-pass, lowering fuel pressure in the second chamber to terminate injection. The amount of fuel injected into cylinders is controlled by the stroke of the shuttle toward the first chamber, which stroke is initially determined by the energizing interval of the electromagnetic valve.
摘要:
A distributor type fuel-injection pump according to the present invention is provided with a rotor which is rotated by an engine. The rotor has a pair of plungers slidable in the radial direction of the rotor, and a fuel pumping chamber is defined between the plungers. The rotor is surrounded by a cam ring which reciprocates the plungers as the rotor rotates, thereby sucking fuel into the fuel pumping chamber and pressurizing the fuel therein. The fuel pressurized in the fuel pumping chamber is distributed to individual cylinders of the engine. A plurality of spill holes are formed in the rotor, communicating with the fuel pumping chamber and opening to the outer peripheral surface of the rotor. A control sleeve to open and close the spill holes is axially slidably fitted on the rotor. First and second spill grooves capable of communicating with the spill holes are formed on the inner peripheral surface of the control sleeve. The first and second spill grooves open or close the spill holes to define the timing for the start of fuel delivery in the fuel pumping chamber and the timing for the end of fuel delivery, thereby determining the amount of fuel delivery.
摘要:
In a fuel injection control system for multi-cylinder internal combustion engines, the speed of the engine is monitored and sampled at predetermined angular intervals of engine revolution to detect instantaneous engine speed values identifiable by individual cylinders. From the successively detected instantaneous speeds is derived an average value which is used as a reference for the instantaneous speed values to detect their deviations therefrom. Cylinder-to-cylinder variations in engine speed are minimized by metering the fuel according to the individually derived engine speed deviations.
摘要:
The engine speed is periodically detected at every predetermined crankshaft angles for obtaining a plurality of engine speed data whose number equals an integral multiple of the number of cylinders of an internal combustion engine. Either maximum or minimum values among the plurality of engine speed data is determined, and such operations are repeated for a duration covering all power strokes within all the cylinders, thereby obtaining a plurality of sets of engine speed data. Then the order of engine speed data giving the maximum or minimum value within each set is obtained, and majority decision is effected to determine which order of data gives the maximum or minimum most frequently throughout all the sets. The difference between the maximum and minimum values is obtained for each set, and the amount of fuel to be supplied to the engine is controlled so that the difference becomes common to all the cylinders. The fuel amount control may be effected by means of an actuator which controls the position of a spill ring of a distributor injection pump.
摘要:
In a fuel injection system having a fuel injection pump of distribution type with an electromagnetic valve controlling the communication between a spill port and a lower pressure fuel chamber, the closing duration of the electromagnetic valve is controlled by a computer so that the closing duration is defined as the sum of prestroke time and actual injection time which are both prestored in one or more memories. The actual injection time is controlled in accordance with engine operating condition, while the prestroke time may also be controlled by manually setting the same or by way of a feedback control. The sum, which defines the closing duration of the electromagnetic valve, may be limited by a maximum value, which may be manually adjustable, so as to prevent excessive fuel flow. The prestroke time may be uniformly controlled through all the cylinders or may be independently controlled for respective cylinders.
摘要:
In a diesel engine control system, an intake air density compensation system is provided for compensating the control amounts of a diesel engine in accordance with the variations of intake air density. The variation amount of the intake air density is indicated by the difference between the control input amount obtained in accordance with an ignition timing closed loop control and the control amount obtained in accordance with an ignition open loop control. The various control amounts of the diesel engine is compensated on the basis of the difference so that the diesel engine is ensured to be optimally operated irrespective of the variations of intake air density.
摘要:
An internal combustion engine has a particulate filter for collecting exhaust particulate matters included in exhaust gas. An oxidization catalyst is supported on the particulate filter. A fuel injection control system for the engine has injection quantity setting means. The injection quantity setting means sets an injection quantity for a post-injection so that the injection quantity is increased toward a basic injection quantity corresponding to a heating value, which is suitable for eliminating exhaust particulate matters collected by a particulate filter. The injection quantity is gradually increased to the basic injection quantity while maintaining temperature of the particulate filter including the oxidization catalyst above a lower limit temperature for inhibiting generation of white smoke. The lower limit temperature is determined in accordance with the injection quantity.
摘要:
In a feedback control system for air/fuel ratio control of an internal combustion engine, in which an integration correcting amount is derived from the output signal of a gas sensor indicative of the concentration of an exhaust gas component, and an engine condition correcting amount read out from a memory is arranged to be renewed in accordance with the integration correcting amount so as to effect learning correction, fuel vapor evaporated in a fuel tank is selectively fed via a canister to the engine by controlling an electromagnetic valve. When the engine is in a predetermined operational condition, the electromagnetic valve is energized to disable a fuel vapor supply system. The learning correction is performed only when the fuel vapor supply system is disabled so that the value of the engine condition correcting amount is not affected by a rich mixture caused by the fuel vapor from the canister.
摘要:
An excessive volume of fuel discharged by a high-pressure supply pump to a common rail due to an opened state abnormality of an inlet metering valve of the pump may result in an abnormal increase in common rail pressure. In the event of such an abnormal increase, a target idle revolution speed is newly set at an abnormal value greater than a normal value as a measure taken to increase an idle revolution speed. Thus, a pressure limiter, which has been once put in an opened valve state by an actual common rail pressure higher than a limit setting pressure, can be prevented from again entering a closed valve state. As a result, it is possible to eliminate idle performance instability caused by repetition of opened valve and closed valve states of the pressure limiter and, hence, assure reliability of the pressure limiter.