JPS5915643A - Electronic fuel injector for 4-cycle v-type multiple cylinder internal combustion engine - Google Patents

Abstract

PURPOSE:To uniformalize injection amount between cylinders by injecting fuel near the upper dead point of every cylinder in an electronic fuel injector for a 4 cycle V-type multiple cylinder internal combustion engine. CONSTITUTION:Intake air which has passed through a hot wire system air flow meter 3 built in an air cleaner 12 is sucked into an internal combustion engine 1 to be distributed to each cylinder. Signals of said air flow meter 3, a throttle valve opening sensor 10 and an ignition coil 4 are supplied to the input of a control unit 5 to control a fuel injection valve 2. Fuel is injected near the upper dead point of every cylinder. Namely, there is no difference of injection amount between the respective cylinders since fuel is injected under the same intake pressure in all cylinders.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electronic fuel injection device for a 4-stroke V-type multi-cylinder internal combustion engine that injects fuel into all cylinders at least once during one revolution of the crankshaft, and particularly relates to an electronic fuel injection device for a 4-cycle V-type multi-cylinder internal combustion engine. The present invention relates to an electronic fuel injection device for a four-stroke type multi-cylinder internal combustion engine that employs a good individual injection method that injects each cylinder individually.

Generally, in a 4-cycle V-type 4-cylinder engine for two-wheeled vehicles equipped with this fuel injection device, the pulp of the intake valve and m-air valve overlap, so in order to prevent intake interference, each cylinder is throttled. , the intake pressure downstream of the throttle valve constantly changes within a range of 14 F for approximately -500 m, and there is a phase between the troughs. On the other hand, the engine is 180
#With the crank mechanism, the firing order is 1→3→4→2. The sequence of steps in the trough cylinder is as shown in Figure 1, and 6 degrees.With this configuration, if one injection of fuel is simultaneously applied to all cylinders at position A in Figure 1, the intake pressure of each cylinder will be The relationship between the fuel injection timing and the injection timing is shown in FIG. 2, and it is clear that all the cylinders inject at different timings, that is, at different intake pressures. Therefore, even if the injection lid characteristics of all fuel injectors are the same, when assembled into an engine, there will be no difference in fuel injection amount depending on the intake pressure, the exhaust gas performance will be worse (r), and the rotation at idle will be lower. The range of fluctuation was large. Figure 3 shows the partial load test results, a-
1 silk 1 cylinder, b the 2nd cylinder, CVi 3rd cylinder, d
indicates the m4 cylinders, and the exhaust gas concentration varies across all cylinders. In addition, the 4th cylinder is divided into 2 parts each with 2 cylinders.
When group injection is performed at positions φA and B in the figure, the relationship between the intake pressure and injection timing of each cylinder is as shown in Figure 5. It is possible to perform two minutes t/y of bottom dead center injection. As is clear from FIG. 5, the first and fourth cylinders inject at a location close to atmospheric pressure, and the second and third cylinders inject at a location where the intake pressure is relatively high.

Therefore, problems similar to simultaneous injection arise.

Figure 6 shows the partial load test results, where a indicates the first cylinder, b
indicates the second cylinder, C indicates the third cylinder, and d indicates the fourth cylinder, and the exhaust gas harshness varies between the 1st and 4th cylinders and the 2nd and 3rd cylinders.

An object of the present invention is to provide an electronic fuel injection system for a 4-cycle V-type multi-cylinder internal combustion engine that can improve exhaust gas performance and idle stability.

The gist of the present invention is as follows. In other words, the intake pressure downstream of the throttle valve constantly changes by about -500 mm from atmospheric pressure, and since there is a phase between each cylinder in a type 3 multi-cylinder internal combustion engine, the intake pressure downstream of the throttle valve changes by 11 times per crankshaft rotation. Whether it is simultaneous injection in which all cylinders are injected during turning or group injection, fuel is injected at different intake pressures. therefore,
Is there a difference in the injection amount of each cylinder, causing exhaust gas between the cylinders? #
It has been confirmed through experiments that the degree varies. Therefore, the present invention aims to improve exhaust gas performance and idle stability by injecting fuel into each cylinder individually, so-called individual injection, and by injecting fuel at the same timing in all cylinders, for example, near top dead center. It is.

Examples of the present invention will be described below.

FIG. 7 shows an embodiment of the present invention.

In the figure, wall air escapes a true wire type air flow meter 3 built into an air cleaner 12, and electricity corresponding to the opening degree of the throttle valve is sucked into the internal combustion engine 1.

The nitrogen gas that has completely passed through the air flow meter 3 flows into the tank and is distributed to the 6 intake cylinders. On the other hand, fuel is sucked from the fuel tank 6 (by the fuel pump 7) and pressurized.
Fuel filter8. Damper 9. The fuel is fed under pressure to the fuel system to which the fuel injection valve 2 is connected.

In the fuel injection lid, the signal from the air flow meter is processed by the control unit 5, and the fuel injection valve 2 is opened in response to the output signal from the control unit 5, and the required amount of fuel is injected into each intake cylinder.

Next, the control system includes sensors that detect the operating state of the internal combustion engine and a control unit 5 that inputs these signals, performs arithmetic processing, and determines the opening time of the fuel injection valve 2. The sensors include a hot wire set air flow meter 3 that detects the amount of intake air, a throttle valve opening switch 1O1 that detects the opening of the throttle valve, and a rotation speed of the internal combustion engine.
Igeun Yong Coil 4 determines fuel injection timing
It consists of The control unit 5 inputs these signals, performs predetermined processing, and turns the fuel pump ON-.
It determines the OFF time and the opening time of the fuel injection valve 2, and outputs the signal.

Next, the operation of this embodiment will be explained. Figure 8 shows a block diagram of the control unit 5.

FIG. 9 is a timing chart of various operation waveforms. Figures 9(a) to 9(d) each show the ignition coil 4.
No. 15 from 1, 42, 43.44. Figure 9 (f
) is determined by the reference pulse waveform shaping circuit 15 as shown in FIG. 9(a).
The waveform obtained by converting to (d) +4fxO is inputted to the input/output interface 13 via the line 16. FIG. 9(e) has the same waveform as FIG. 9(a) and is a reference signal υ, which is input to the input/output interface 13 via the line 17. In addition, analog signals and digital signals for detecting the entire operating state of the internal combustion engine are input to the human output interface 13 through the distortion circuits 14 and 16, respectively. These input signals are processed and the fuel bongua is turned on → off.
Perform F and also determine the opening time of the fuel injection valve.

The calculated valve opening time is output in the following manner and moves the fuel injection valve.

When the pulses f-1 and f-3 are input δ, the waveform of the line 18 becomes high level for the above-mentioned valve opening time as shown in FIG. 9 (?) at that timing. When the pulses of ma/ko, f-2, and f-4 are input, the waveform as shown in Fig. 9 (h) is #j.
! 19 is output. The waveform in FIG. 9(i) is the signal output to line 20, and the pulse of f-1 is...irrepel! 7. The quality level is reached by the f-3 pulse. FIG. 9(j) is an inverted waveform of FIG. 9(i) and is output to i21. The waveform shown in Figure 9(k) is the signal output to ffM22, which goes high at the f-2 pulse, and f-4.
It becomes low level with the pulse of . Figure 9 (1) is shown in Figure 9 (
k) is output on line 23 with a waveform inverted. Waveform (f)
The waveform (m) obtained by ANDing (+) and (+) is output to the fuel 1@injector 21 of the first cylinder. The fuel injection valves 22, 23, and 24 of the 2nd, 3rd, and 4th cylinders have (h) and (k), respectively.
Waveform (P) obtained by ANDing (f) and (j), (h) and (1)
), (n), and (o) are output. Therefore, the injection timing of the aroma site? J1, as shown in Fig. 10, and both the trough cylinders are injected near top dead center as shown in Fig. 10 A, H, C, and D, and the relationship between the intake pressure and injection position in the trough cylinder is shown in Fig. 11. This results in the tumor shown in . As is clear from FIG. 11, fuel is injected at the same intake pressure for all the air. Therefore, if the injection amount characteristics of the injector are moderated on paper, variations in the exhaust gas TIk degree can be eliminated.

In order to confirm this, a partial load test was carried out on the engine, and Fig. 12 shows the measurement results of exhaust gas concentration, where a is the first cylinder, b is the second cylinder, C is the third cylinder, d
indicates the fourth cylinder. As is clear from the figure, the range of variation in exhaust gas concentration has become smaller.

However, it is not possible to perform individual injections like Uememi's in the entire operating range. In other words, in a region such as when the load is high, the calculated valve opening time of the fuel injection valve is
/2 rotation time pulses f-1 to f- in Figure 9
It gets louder over the course of 3 hours. Therefore, as shown in FIG. 4, the injection is performed in groups. The conditions for switching between group injection and individual injection are as follows.

Switching condition from individual injection to group injection '1' +,
, +t, >TN/2
... (Switching condition from 1 group injection to individual injection 1゛鵞+tb<'1'N/2
... (2) (1), (2), 1゛I: Fuel 1
@ Injection valve opening time (calculation result) TN: Time for the engine to rotate once, lb D Fixed time t, (t b This deviation means that in the group injection operating range, the throttle valve is fully open. Since the regions are close to each other, there is almost no difference in intake pressure, so there is no variation in exhaust gas concentration.Furthermore, since hysteresis is provided in switching even in the switching operation region, good operating performance can be obtained.

As described above, according to one embodiment of the present invention, fuel is injected near the top dead center of all cylinders. In other words, since fuel is injected at the same intake pressure in all cylinders, there is no difference in the injection amount and variations in exhaust gas concentration can be reduced, improving stability at idle and exhaust gas performance. effective. In addition, according to the embodiment of the present invention,
Individual injection can be performed as long as the reference cylinder discrimination signal is provided. In addition, by switching between individual injection and group injection and providing hysteresis in the switching conditions, good operating performance can be achieved in all areas.

As described above, according to the present invention, it is possible to improve the stability of the exhaust gas exhaust gas idler.

[Brief explanation of drawings]

Figure 1 is a diagram showing the relationship between single injection position and engine operating process when all cylinders are injected simultaneously, Figure 2 is a diagram showing the relationship between intake pressure and injection timing for simultaneous injection, and Figure 3 is a diagram showing the relationship between simultaneous injection and injection timing. Figure 4 is a diagram showing the relationship between the injection position and engine operating process during group injection, and Figure 5 is a diagram showing the relationship between the injection position and engine operating process during group injection.
Figure 6 shows the relationship between intake pressure and injection timing during group injection, Figure 6 shows the measurement results of exhaust gas configuration during group injection, and Figure 7 shows the relationship between 4-stroke V-type multi-cylinder internal combustion. A system diagram of an electronic fuel injection device, Fig. 8 is a pronk diagram of the control unit 7 adopted in the present invention, Fig. 9 is an operating waveform, and Fig. 10 is an injection position and engine operation when the present invention is implemented. FIG. 11 is a diagram showing the relationship between the processes, FIG. 11 is a diagram showing the relationship between intake pressure and injection timing during individual injection, and FIG. l...Internal combustion engine, 2...Fuel injection valve, 3...Hot wire type air flow meter, and...Control unit. $5 Figure '1 (6 and 7 CP>

Claims (1)

[Claims] 1. An intake system having independent intake passages each communicating with a plurality of cylinders, and in which a throttle valve is disposed in each intake passage to prevent intake interference due to overramp of the intake valve and exhaust valve of the internal combustion engine. In an electronic fuel injection device for a four-stroke V-type multi-cylinder internal combustion engine that injects fuel to all cylinders at least once during one rotation of the crankshaft, fuel is injected to each cylinder individually and to all cylinders in the same process. An electronic fuel injection system for a 4-cycle V-type multi-cylinder internal combustion engine featuring: