JPS58155241A - Air-fuel ratio control device for internal-combustion engine - Google Patents

Abstract

PURPOSE:To prevent the excessive enrichment of air-fuel ratio at the time of deceleration by providing an air valve to be opened and closed in accordance with the extent of load in a bypass passage around a throttle valve in a system provided with a fuel regulating means in the upper stream of a branched part of a suction pipe connected to each cylinder. CONSTITUTION:The captioned device controls an injection valve 4 as a fuel- regulating means by a computation control device 3 in accordance with outputs of a suction amount detecting means 2 and a revolution number detecting means 11, while at the same time, controls the negative feedback of the injection valve 4 on the basis of the output of an air-fuel ratio detecting means 13. At this stage, a bypass passage around a throttle valve 5 in a suction pipe 9 is connected to the suction pipe 9, and an air valve 7 is provided in this bypass passage. This air valve 7 is opened by the computation control device 3 when the suction air amount is increased to surpass a fixed value at the time of acceleration, and controlled to close when the suction air amount is decreased to surpass another fixed value by deceleration and then a fixed time passes.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electric air-fuel ratio control device for an internal combustion engine, which is intelligently controlled and has an air supply means that supplies air during deceleration of the engine. As an electric air-fuel ratio control device, it is electrically driven, and all injection cells that open according to the driving time are arranged for each cylinder, and control is performed for 6 hours of driving according to the output of the intake air amount detection means. A device w is known.

However, in the conventional system, even though there is a difference in the fuel discharge amount % @VC machine with respect to the driving time of the "M injector" provided for each cylinder, this machine difference causes variations in the air-fuel ratio between the cylinders, resulting in poor engine operation. Moreover, it will cause exhaust gas pollution.

Further (rc, L is applied to the output of the fuel-fuel ratio detection means installed in the exhaust pipe)
9 Negative Feedback Control Even in the case of negative feedback control, it is not possible to fully perform the sophisticated negative feedback control unless there is individual fuel-fuel ratio detection means before the exhaust pipe of each cylinder.
The injection valve is required to have highly accurate characteristics, and the electric nitrous-fuel ratio control device for the knee engine has to have a curved cylinder, since the injector is placed in each cylinder. Ta.

In order to eliminate the above drawbacks, ^11 Injector valve, each air of the engine, mixture to the cylinder? An electric nitrous fuel ratio control device for a piston combustion engine is known, which is installed upstream of the branching part of the intake pipe for distribution. Moreover, since a part of the injected fuel is supplied in an adult state at a moving speed T which is slower than air, the amount of air sucked into each jaw and the amount of air are regulated according to the amount of air. As a result, when the engine is operated dynamically, the air-fuel ratio of the air-fuel mixture sucked into the cylinder increases. In particular, when the engine decelerates, for example when the throttle is returned to full throttle, the intake air changes suddenly, but the fuel that has already been injected remains in the intake pipe, and the accumulated amount of fuel The mixture in the cylinder became overrich and misfired, and when the influence of the retention amount decreased, it ignited and generated all the torque, so the engine generated torque suddenly changed, resulting in an abnormal collision 's'.

In addition, a problem occurred in that a large amount of unburned exhaust gas special VC hydrocarbons was emitted.

Therefore, an object of the present invention is to supply air according to the amount of fuel remaining in the intake pipe when the engine decelerates, in order to eliminate the drawbacks of the conventional device as described in the paper. An object of the present invention is to provide a fuel ratio control device for an internal combustion engine that does not cause misfire due to richness.

Hereinafter, we will discuss an embodiment of the present invention based on Figure 1 below.
A heart to explain. FIG. 1 is a block diagram showing the main parts of the internal combustion type nitride-fuel ratio control device according to the present invention.ωf
The computer control device 3 determines whether the air-fuel mixture supplied to the engine is H [ The air-fuel ratio of the legs is different from that of the engine.
Has f40 control tray. Furthermore, the control device 3 receives all the outputs of the air-fuel ratio detection means 13 provided in a part of the exhaust pipe 12 of the engine, the Ai+ suction amount detection stage 2 and the rotation speed detection means 11.
Detection error and metering error of the injection valve 4, the devilish state in which the engine is placed, etc.
I will do it.

As shown on paper, the threshold 9 control device 3 controls the nitrogen-fuel ratio, so when the engine is operating in a steady state, the amount of live air sucked into each cylinder 10 and the 1114 injection adjustment ratio are adjusted according to the amount of air. Since there is a constant time difference between the fuel and the fuel that has been adjusted, the air-fuel ratio is controlled to be constant at FQr. In other words, the amount of fuel retained is determined by the engine speed, intake air amount, and air-fuel ratio. Next, when the throttle valve 5 is rapidly changed from fully open to half open in order to decelerate the engine, the behavior of the air-fuel ratio is shown in Figure 2.
2, the intake and exhaust gases detected sharply decrease, but each cylinder has 10
As shown in FIG. 2, the fuel sucked in is heard for td seconds, and the air-fuel ratio in the valley cylinder 10 becomes rich for ta seconds as shown in FIG. In particular, when the richness is low, the overrich vCL will cause a misfire and the torque generated by the engine will be low, and when the rich history becomes small, the ignition will cause the elytorque to return, and because it is rich, the torque will be large. This will have a huge impact on the organization.

However, in the present invention, as shown in the 11th section I, a plane 7 is installed in the passage where the throttle well 5 is connected.
is provided, and by opening this vacant ff7, the bypass 1 is constructed without passing through the scale plane or the throttle box 5, thereby eliminating all the drawbacks mentioned above.

Next, the operation of the nitrous fuel ratio control device of the present invention will be explained with reference to the 31st meeting.

The intake air pressure of the engine increases as the engine accelerates, resulting in QA,
When the value exceeds the value, the arithmetic and control unit 3 opens the air valve 7. The air flow amount QA+ is set to correspond to the air flow when the engine load is sufficiently large, and there is almost no jump in the air flow caused by the opening of the air valve 7. . Next, due to the deceleration of the engine, the amount of air decreases and exceeds a value QA2, and after a time period T has elapsed, the arithmetic and control device 3 closes the nitrogen chamber 7. Therefore, during the time T, the engine is inhaling the nitrogen intake amount QAVI, which is determined by the throttle box 5 and the pipe whistle box 7. At this time, the richness of the air-fuel ratio is alleviated because the fuel that had accumulated in the intake pipe is inhaled as excess fuel, or because the decrease in the amount of air is suppressed. Figure 3 V (- indicates that the air should not be activated in 5P7' (the pattern when the air volume is reduced in 8 is broken and assimilated).

Next, when time T has elapsed and the 7 cylinders are closed, a fuel oil residue corresponding to the air amount QAy is discharged, and a rich phenomenon occurs, but the stable where the air amount decreases is small, and therefore Since the amount of excess fuel generated is not small, the impact on the engine is negligible. In this way, the enrichment phenomenon caused by the deceleration e is greatly alleviated, but the following points need to be kept in mind. In other words, the amount of air that becomes QAV+ has to be made large enough to prevent misfires from occurring due to excess fuel being discharged, and if jk is made too large, the engine will not be decelerated sufficiently even though deceleration operation is performed, resulting in poor driving performance. It is to thwart. Therefore, the effective diameter of the air valve 7 and the time T should be determined in consideration of the operating performance of the engine.

What about figure 4? An example is shown in which the opening of the air cell 7 is completely reduced and the circuit is closed. As shown in FIG. 4, when the opening is gradually reduced, the degree of change is less severe than when the seven air valves are suddenly closed, so it is possible to eliminate most of the sound sequences on both sides when the circuit is closed.

Figure 5 shows how to reduce the opening/closing time of 9'P7. An example of the case where 4 + lil f is carried out is shown (7).
1 opens and closes the box 7, and the closing time is 'I+'2+t3・
It is possible to obtain the same effect as the embodiment shown in FIG. 4 yc by gradually increasing T2ta-1 and then decreasing it gradually.

In the embodiments described above, a method has been described in which the deceleration detection sound of the engine is evaluated based on the intake air pressure condition, but other parameters representing the load state of the engine, such as suction pipe negative pressure,
A similar effect can be obtained by opening the throttle valve 11L.

As is clear from the above explanation, according to the present invention, in the accelerating state VC of the engine, the throttle valve is opened beforehand. Since this air is given to the engine, it temporarily alleviates the decrease in air pressure when the engine suddenly decelerates, thereby gradually slowing down the enrichment of the air-fuel ratio and reducing engine impact noise. Furthermore, it has the excellent effect of minimizing deterioration of deceleration performance due to a decrease in air amount.

4. Simple drawings at 81°C. Figure 1 is a block diagram showing the main parts of an air-fuel ratio control device for an internal combustion engine, which shows one embodiment of the invention, Figure 2 is a diagram showing the behavior of the air-fuel ratio, and Figures 3 to 4 are diagrams showing the behavior of the air-fuel ratio. FIG. 5 is an explanatory diagram showing the operation of FIG. 1.

1...Air cleaner, 2...Intake air amount detection means, 3.
... Arithmetic control device, 4... Fuel metering means, 5... Throttle square, 6... Throttle valve opening detection means, 7.
...Air valve, 8,9...Intake pipe, 1()...Cylinder,
11... N rotation speed detection means, 12... Exhaust pipe, 13.
...Air-fuel ratio detection means.

Note that the same reference numerals in the figures indicate the same or corresponding parts.

Agent Kuzu Nobuo - Figure 1 Figure 2

Claims (1)

[Claims] (1) At least one fuel metering means that is electrically driven and adjusts the amount of fuel according to the operating parameters of the engine is provided upstream of the branch of the intake pipe that distributes the entire air-fuel mixture to each cylinder of the engine. In an air-fuel ratio control device that performs all air-fuel ratio control of an engine, there is an air valve installed in a passage where air passes from upstream to downstream of the throttle valve, and when the engine load increases beyond a predetermined value, An air-fuel ratio control device for an internal combustion engine, comprising: a control device for opening an air tank and closing the air valve when the engine load decreases beyond a predetermined value and a predetermined time elapses; (2. In the air-fuel ratio control device for an internal combustion engine according to claim 1, when the engine load decreases by exceeding a predetermined value, after a predetermined period of time including A nitrogen-fuel ratio control device for an internal combustion engine, characterized in that the opening degree of the air valve is gradually reduced.