JPS6017939B2 - Electronically controlled fuel injection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electronically controlled fuel injection system for an engine, and more particularly to an acceleration fuel injection system during engine acceleration.

Conventionally, this type of device supplies the fuel injection solenoid valve with a main injection pulse that determines the amount of fuel commensurate with the amount of intake air required by the engine, in synchronization with engine rotation, and injects the fuel. When accelerating the engine, an acceleration pulse is supplied to the electromagnetic valve independently of the main pulse, without being synchronized with the engine rotation, thereby increasing the amount of acceleration. That is, a pulse resulting from the logical sum of the main pulse and the acceleration pulse is supplied to the fuel injection solenoid valve.
For this reason, there is a possibility that the main pulse and the acceleration pulse overlap in time, and if they overlap, the effect of the acceleration pulse will be substantially weakened or eliminated, resulting in undesirable disadvantages in terms of engine operation such as deterioration of driving performance. have. In order to solve the above-mentioned drawbacks, the present invention provides an adder circuit section that separately opens the fuel injection solenoid valve for the overlapped time when the main pulse and the acceleration pulse overlap in time. The object of the present invention is to provide an electronically controlled fuel injection device capable of appropriately increasing the amount of acceleration without regard to the problem of temporal overlap of acceleration pulses.

The invention will now be explained by way of example, which is illustrated in the drawings.

In the block diagram of FIG. 1, 1 is an engine, and 2 is a signal generator that generates a rotational speed signal synchronized with engine rotation, such as an ignition signal generator. 3 is a known main pulse generation circuit which calculates the pulse width of a main pulse that determines the amount of fuel required by the engine, that is, the amount of intake air; the main pulse is output in synchronization with the engine rotation.

4 is an acceleration sensor that uses, for example, a throttle switch that is linked to a throttle valve of the engine.

5 is an acceleration pulse generation circuit which receives an acceleration signal from the acceleration sensor 4 and outputs an acceleration pulse, and 6 is an OR circuit which takes the OR of the main pulse and the acceleration pulse.

Reference numeral 7 denotes a solenoid valve drive circuit for amplifying the pulse output from the OR circuit 6, and 8 denotes a fuel injection solenoid valve opened and closed by the drive circuit 7, which is provided near each intake boat of the intake manifold of the engine.

9 is a fuel system.

FIG. 2 shows the acceleration pulse generating circuit 5, which is a main part of the present invention, and FIG. 3 shows the output waveforms of each block in FIG. 1. The operation will be explained below using both figures.

Signal A is an engine ignition signal output from the signal generator 2, and signal B is a main pulse output in synchronization with signal A for determining the fuel injection amount. Signal C is acceleration sensor 4
The output signal D is the acceleration pulse output from the acceleration pulse generation circuit 5, and the signal E is the output signal from the OR circuit 6. The set-reset flip-flop (hereinafter referred to as SR/FF) 2a is set by the acceleration signal C from the acceleration sensor 4 applied to the terminal 2N of the acceleration pulse generation circuit 5 shown in FIG. 2, and the output Q of the SR/FF 2a is set at a high level. becomes PNP
Transistor 2P is turned off. Therefore, capacitor 2
d begins to be charged through the resistor 2e and the NPN transistor 2f. 2L' comparator, the division ratio of resistors 2i and 2k, the comparison voltage determined by the power supply voltage +B, and the capacitor 2d.
, the voltage at the connection point F of the resistor 2e is compared, and as the capacitor 2d is charged, the potential at point F changes as shown in FIG. , and resets SR/FF2a.

During this time, the output terminal Q of the SR/FF 2a is at a high level, and this becomes an acceleration pulse, which is output as a signal D from the output terminal 2M. Here, when the main pulse B is output during the period when the capacitor 2d is being charged, that is, when the acceleration pulse c is being input, the main pulse input terminal 20 becomes high level and is passed through the adder circuit through the resistor 2i. Turn on the NPN transistor 2h forming the . Therefore, NPN transistor 2f is turned off, so capacitor 2
Charging of d is temporarily stopped. Since this stopped state continues while the main pulse B is output, the acceleration pulse becomes longer by the pulse time of the main pulse, and the two pulses are temporally added. The pulse outputs D and B from the main pulse generation circuit 3 and the acceleration pulse generation circuit 5 are logically summed by an OR circuit 6 and output as a signal E, which is then sent to the solenoid valve drive circuit 7.
is amplified and drives the solenoid valve 8 to open. In the above embodiment, the adder circuit section is configured to add the main pulse to the acceleration pulse when overlapped, but conversely, it is also possible to add the acceleration pulse to the main pulse in the same manner as above. Various other configurations are also possible. In short, when the main pulse and acceleration pulse overlap in time,
Any configuration is sufficient as long as the pulse time of this overlapping time is separately supplied to the solenoid valve 8. As described above, the electronically controlled fuel injection device of the present invention is equipped with an adder circuit section that outputs a pulse at a time when the main pulse and the acceleration pulse overlap in time, and when the two pulses overlap, The fuel injection solenoid valve can be opened separately during the overlap period, and an appropriate acceleration increase can always be achieved during acceleration, which has the advantage of not causing deterioration of engine operating performance.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is an electric circuit diagram of the acceleration pulse generation circuit shown in FIG. 1, and FIG. 3 is an output signal waveform diagram of each block in FIG. 1. . 1...Engine, 3...Main pulse generation circuit, 5...Acceleration pulse generation circuit, 8...Fuel injection solenoid valve, 2h, 2f...Addition circuit Each transistor forms a part. Figure 1 Figure 2 Figure 3

Claims (1)

[Scope of Claims] 1. Main pulse generation means that outputs a main pulse that determines the amount of fuel according to the engine demand in synchronization with the engine rotation, and an increase pulse that determines the amount of fuel to be increased during engine acceleration etc. when the engine rotates. In an electronically controlled fuel injection device equipped with an increase pulse generation means that outputs an increase pulse without synchronization with the main pulse, when the main pulse and the increase pulse are outputted temporally overlappingly, a pulse that is the sum of the overlapping time widths is used. An electronically controlled fuel injection device characterized in that it is provided with means for outputting a pulse of a certain width. 2 Main pulse generation means that outputs a main pulse that determines the fuel amount according to the engine demand amount in synchronization with the engine rotation, and outputs an increase pulse that determines the acceleration increase fuel amount during engine acceleration etc. without synchronizing with the engine rotation. In an electronically controlled fuel injection device, if the main pulse and the increase pulse overlap in time, one of the pulse output means is interrupted and restarted when the other pulse ends. What is claimed is: 1. An electronically controlled fuel injection device comprising means for outputting a pulse having an added time width as a result of the above steps.