SU466344A1 - Fuel injection system for internal combustion engine - Google Patents

Description

one

FIELD: engine building.

The fuel injection systems for an internal combustion engine with spark ignition are known, which contain at least one electromagnetic injector located on the intake manifold with a shut-off element located in the fuel supply channel, an electronic control device having a pulse generator, to the input of which the transducers of operating mode sensors are connected, and to the outlet - a nozzle winding, and a fuel dispenser, equipped with a sensing element connected to the outlet pipe cavity, and controlled schtokom them.

The proposed system differs from the known ones in that the fuel metering device is mounted on the injector and the control rod is connected to the injector valve body.

In addition, the output pulses of the pulse generator have a sawtooth shape with a gentle forward and steep trailing edges, and the time constant for the recovery of the injector winding current is longer than the maximum pulse duration of the pulse generator.

This embodiment of the fuel injection system provides improved metering accuracy and reduced power consumption.

FIG. 1 shows a diagram of the proposed fuel injection system for an engine.

spark ignition internal combustion; in fig. 2 is a graph of the change in cyclic feed versus change in vacuum in the intake manifold (engine load) and at various voltages.

stabilization; in fig. 3 - graph of change

feed cycle depending on the change

rarefaction and at various durations

pulses.

Fuel injection system (see fig. 1) in

spark-ignition internal combustion engine contains an electromagnetic nozzle located on the intake manifold (not shown), in the housing 1 of which the magnetic circuit 2 is placed

winding 3 and measles 4, which performs the function of a locking member and provides, when landing on the saddle 5, the fuel supply channel 6 overlaps, an electronic control device having a voltage regulator 7 and a pulse generator 8, to the input of which are connected transducers of sensors 9 engine operating modes, For example, engine thermal state, acceleration and others, and winding 3 to the input

nozzles.

Anchor 4 is pressed against the saddle 5 by means of a leaf spring 10.

A fuel dispenser with a diaphragm 11 and a control rod 12 passing through the separation membrane 13 and in contact with the core 4 is mounted on the nozzle body 1 of the nozzle. Submembrane chamber 14 of the dispenser is connected to the inlet pipe cavity through the throttle valve by means of a pipeline 15. Pipeline 16 supplies fuel to the injector at a constant pressure.

The system works as follows. When the starting pulse is applied by the chopper 17, the pulse generator 8 generates a pulse applied to the winding 3 of the nozzles. The impulse from the generator 8 should be sawtooth with a gentle forward and steep rear fronts. With rectangular pulses of the generator 8, the winding 3 of the nozzles must have a large number of turns, so that the constant recovery time of the current of the winding 3 exceeds the maximum pulse duration. In this case, the current in the winding 3 will have a sawtooth shape with a gentle forward and steep rear fronts. With a smooth increase in the current in the winding 3, the magnetic flux increases gradually. If there is no vacuum in the submembrane chamber 14, the bore 4 begins to move to the open position of the fuel supply channel 6 after the force of attraction of the magnetic core 2 exceeds the force of the spring 10. As soon as the measles 4 moves away from the saddle 5 through the fuel supply channel 6, the fuel starts to inject into the intake engine tract. In the absence of vacuum in chamber 14, the delay in opening channel 6 with respect to the beginning of the pulse from generator 8 is small, and therefore the duration of fuel injection almost corresponds to the pulse from generator 8. When the pulse from the generator 8 ends, the measles with spring 10 will overdeal to close position of channel 6.

In partial load modes, an underpressure from the exhaust pipe is transmitted to chamber 14, and a force is generated on the membrane 11, which is transmitted through the rod 12 to measles 4. In this case, the rise of the core 4 begins with a delay relative to the beginning of the pulse. This delay is the greater, the greater the vacuum in chamber 14, since the force from the magnetic circuit 2 must overcome the force of the spring 10 and the rod 12. The lowering of the core 4 to the saddle 5 and the end of the fuel supply in this case also occurs when the pulse from the generator 8 ends .

FIG. 2 shows a graph of the change in cyclic feeds as a function of the vacuum in the intake manifold, where, along the axis

the abscissa shows the negative pressure change in the LR pipeline (kg / cm), and the ordinate-cycle axis AV (mm / cycle). Curve 1 shows the change in cyclic feed at a stabilization voltage of 7.8 volts, and curve II shows a voltage of 10.6 volts. As can be seen from this graph, an increase in the stabilization voltage can provide an increase in cyclic feeds

high vacuum values in the intake manifold.

FIG. 3 shows a graph of the change in cyclic nodach as a function of the vacuum in the intake manifold, but with the axis

the abscissa is the delay of the AR (kg / cm), and on the ordinate-cycle the feed is D1 / (cycl). Curve P1 shows the change in cyclic feed at a pulse duration of nm equal to 10.4X10 sec, and curve IV -

at 12.4 x 10 sec.

With an increase in the pulse duration by almost the same value, the cyclic nodach changes at the same vacuum values.

By varying the pulse width and duration from the generator 8, an accurate pre-tuning of the injection system is achieved, and the dispenser, together with the nozzle, increases the accuracy of the fuel supply due to the generation of pulses of almost constant duration by the generator 8.

Subject invention

Claims (3)

1. Fuel injection system for a spark ignition internal combustion engine containing at least one placed on the inlet pipe of an electromagnetic nozzle with a shut-off element located in the fuel supply channel, an electronic control device having a pulse generator, to the input of which transducers of operating mode sensors are connected, and an output winding of the injector and a fuel metering unit equipped with a sensing element connected to the output to the cavity of the exhaust pipe, and the control rod, characterized in that, in order to improve the accuracy of the fuel metering, the metering device is installed on the nozzle, and ravl yuschy rod coupled to the injector locking body. 2. The system according to claim 1, characterized in that the output pulses of the pulse generator have a saw-tooth shape with a gentle forward and steep trailing edges. 3. The system of claim 1, wherein that, in order to reduce the consumed energy, the time constant of the recovery of the injector winding current is longer than the maximum pulse duration of the pulse generator. W f w  I / 2 13 12. ,15 .j .sixteen .sL-e ten dV pp cycle 80 About 0.2 0, tfО, and 0.8 cn Ф111 / 1 iV mp cycle 0.20.60.8 tpui 3