JPS59194056A - Fuel control device for engine - Google Patents

Abstract

PURPOSE:To prevent the lowering of output and the increasing of fuel cost at the time of acceleration for sure by memorizing the increased amount of fuel and rewriting and correcting the increased amount of fuel in accordance with the turbulence of the air-fuel ratio at the time of acceleration for obtaining a proper increased amount of fuel constantly. CONSTITUTION:In a control part 21 to control fuel for supplying to an engine 1 from a fuel supply means such as a fuel injection valve 5 and the like, a fuel increasing means 22 to increase the amount of fuel in accordance with the output of an acceleration detection means 23 is provided. For obtaining a proper increased amount of fuel at the time of acceleration by this increasing means 23, a memory means 24 to memorize the increased amount of fuel, an air-fuel ratio change detection means 25, and a rewriting means 26 for the increased amount of fuel are provided. The air-fuel ratio change detection means 25 is constructed to compare the fuel lean time for acceleration obtained on the basis of the output of an O2 sensor with the fuel lean time of stationary operation for detecting the turbulence of the air-fuel ratio at the time of acceleration. The increased amount of fuel in the memory means 24 is rewrited and corrected in the rewriting means 26 for reducing this turbulence.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a fuel control device for an engine, and particularly to a device for appropriately controlling fuel during acceleration.

(Prior Art) Conventionally, as seen in Japanese Patent Publication No. 4.7-38665, the amount of fuel injection ffJ is controlled according to intake pipe negative pressure, engine speed, etc. 1lII'? In addition to basic fuel control, a control device is known that increases the amount of fuel during acceleration. This device aims to improve acceleration performance, and since there is an inherent tendency for fuel shortage to occur due to a sudden increase in the amount of intake air during acceleration, it is necessary to supplement the fuel in this case. This is what I did. However, this conventional device only experimentally determines the fuel increase value during acceleration, so if there are variations in performance between engines or changes over time, the above fuel increase value may not always be accurate. There have been cases in which the engine has not achieved an appropriate engine speed, and the increase value has been too large, resulting in poor fuel efficiency, or the increase value has been too small, resulting in insufficient acceleration.

(Object of the invention) The object of the present invention is to eliminate the drawbacks of such conventional devices,
It is an object of the present invention to provide a device capable of appropriately maintaining a fuel increase value during acceleration even if there are variations in performance among engines or changes over time.

(Drawing of the invention) As shown in the overall configuration diagram of FIG.
'? There is a vaporizer. ) includes a type increasing means 22 for increasing the amount of fuel according to a detection signal from an acceleration detecting means 23. In order to optimize the fuel increase m value during acceleration by the increase means 2.2, a storage means 24 for storing the fuel increase RFI value, an air-fuel ratio fluctuation detection means 25, and a fuel increase G1 value rewriting means 26 are provided. is established.

The air-fuel ratio fluctuation detecting means 25 compares the fuel lean time during acceleration determined based on the detection signal from the 02t sensor with the fuel lean time during steady operation, or compares the fuel lean time during acceleration with the fuel lean time during acceleration.
A drop in the air-fuel ratio during acceleration is detected by detecting engine vibration vJ (acceleration hesitation). 71 (The switching means 26 is an output of the detecting means 25)J
In response to this, the fuel increase value stored in the storage means 24 is rewritten and corrected so as to reduce the droop in the air-fuel ratio.

(Example) In FIG. 2, 1 is an engine, 2 is an intake passage, and 3 is an exhaust passage. The intake passage 2 is provided with a throttle valve 4 and a fuel injection valve 5 downstream thereof. This fuel injection valve 5 is controlled by a control unit 20 using a microcomputer.

11 is an air flow meter that detects the amount of intake air, 12 is a pressure sensor that detects the pressure in the intake manifold, 13 is an engine rotation speed sensor, 14 is a throttle opening sensor,
15 indicates the richness of the mixture depending on the amount of 02 in the exhaust gas,
This is the 02 sensor that detects the lean state. These detection signals are input to the control unit 20.

The control unit 20 is composed of a microprocessor (not shown), memory, interface, etc., and has a ROM map of fuel injection amount corresponding to the engine speed and intake manifold pressure in the memory, and the operating state can be determined from this ROM map. A corresponding fuel standard control value is determined. The fuel control during steady operation is 0.
The above fuel standard control value is corrected by feedback control according to the signal from the second sensor 1/15, and the amount of fuel is increased when the engine is in a rich state, and decreased when the engine is in a lean state. , the rich state and lean state are repeated at appropriate intervals. Roughly speaking, the above memory stores a correction coefficient that determines the fuel increase value during acceleration in accordance with the rate of change in the J slot which indicates the degree of acceleration and the pulse width for fuel injection depending on the operating condition. A map for correction coefficient learning values that is stored, and a tool 211 that stores the lean time (duration of lean state) during steady operation and operation in correspondence with the engine speed and load (intake manifold pressure). The memory 1a of these maps can be changed. Also, the acceleration operation state can be detected using the detection signal from the throttle opening sensor 14. Based on (the change is 1l)
This is done by going to iJ. Based on this detection, during acceleration, if the condition is lean, the fuel injection amount is increased according to the correction coefficient read from the map.Meanwhile, the lean time at this time is compared with the lean time during steady operation, and the difference is calculated. The above correction coefficient is rewritten accordingly. In this way, each means is substantially included in the control unit 20 in accordance with the above-mentioned overall M4 diagram.

Flowcharts for controlling this device are shown in FIGS. 3 to 6.

In the main routine shown in FIG. 3, after initialization in step 31, the manifold pressure detection signal from the pressure sensor 12 is A/D converted in step 32. Next, subroutine (I) for acceleration determination
After passing through the leave routine (I) for correcting the roundness of J:i and the acceleration correction coefficient, the process returns to step 32 and repeats the flow.

For acceleration determination (in I>, the fourth
As shown in the figure, in step 33, the signals from the throwers 1 to 14 are subjected to Δ/D conversion, and in step 34
is the difference in throttle opening between the current detection and the previous detection (θ−
θh−θn−1) is obtained. Next, this thrower opening degree difference θ is compared with a predetermined reference value θ1, etc., and an accelerated operation state and a steady operation state are distinguished depending on θ2, θ1, or a cup (step 35). If the condition is d, the discrimination value A is set to 1, and if the operation is in steady state, the discrimination value is set to O, and the value is recorded in the register (step 36).
．． 37>.

In the routine (It) for rewriting the acceleration correction coefficient, as shown in FIG. 5, it is determined in step 38 whether or not the operation is steady (Δ-0). If the steady operation is in step 1'), step 3 is
4 from 2 Senri 15. The lean state changes from the lean state to the rich state based on the current state. Inside memory 1 (step 40, when fi is changed).

*If the operation is being performed, it is determined in step 41 whether or not the lean state has changed from the rich state.
If there is no change, it is further determined whether or not the lean state is reached (step 42), and if the lean state is determined, the lean time measurement value K is incremented by +1 (step 43). In other words, the lean time during acceleration is detected by increasing the measured value K of the lean time bar 1 at regular intervals from the lean state to the rich state. When the state changes to a rich state, the lean time during acceleration is compared with the lean time during steady operation determined from the lean time map, and it is determined whether ≧t (step 44).
, if ≧1, the correction coefficient learning value cA in the correction coefficient learning value map corresponding to the condition at this time is changed to IITj, which is added by mΔCΔ, and is stored (step 45). Here, m is the difference between the two lean times (K-
The value corresponding to t), 80A, is the set value. On the other hand, 1((
If t, the correction coefficient learning value CA is ΔC8 (P is subtracted, and if this subtracted value is larger than 1, the correction coefficient learning value in the map is rewritten to this value, memorized, and subtracted. If the value is smaller than 1J, CA is stored as 1 (steps 47 to 49).In step 48, OA is
This is to prevent fuel from being reduced during acceleration.

After rewriting in this way, the lean time measurement value 1
is set to O (step 50).

FIG. 6 shows an interrupt processing routine, which starts, for example, at BTDC60' and first begins at step 51.
In step 52, the engine rotational speed is determined by periodic measurement 81, and the operating state is detected from the engine rotational speed JJ and the manifold pressure.

Next, in step 533, Mδ stone injection I? The fuel fuel base 1 (j control value T1) corresponding to the operating condition is calculated from the ROM block of i, and further feedback correction is performed based on the signal from step 54t" The fuel control λ11-11' is determined. Then, in step 55C, it is determined whether or not the engine is in acceleration operation (A=1), and if it is in acceleration operation, it is roughly determined whether or not it is in a lean state (step 56). , in the lean state, the learned value OA corresponding to the throttle opening change rate etc. found from the correction coefficient learning value map is the fuel control value z.
'I got rid of this and increased the amount of fuel I got FJ ffi
T is calculated (step 57). And in this case, the increased amount of fuel III'! Fuel injection is performed when a predetermined injection timing is reached, using the fuel control value -l i / when the engine is in steady operation or not in a lean state even during acceleration (steps 58 and 59).

By controlling the control according to the above flowchart A.--T, the amount of fuel is increased when the fuel is in a lean state during acceleration, and even if this increased amount (correction coefficient learning value cA> is initially inappropriate), It is rewritten and corrected in steps 45 and 46, and the corrected increase value is given the next time acceleration under the same conditions is performed.After this operation is repeated to a certain extent, the learning value stored in the map is The value CΔ is corrected with high precision, and the increased fuel is immediately supplied to the appropriate value in response to the acceleration operation.

In addition, as a means for rewriting and correcting the fuel increase value according to the deterioration of the air-fuel ratio, in the G and I of the above embodiment, for example, vibration caused by the acceleration control is detected, and the correction coefficient learning value CA is adjusted accordingly. Rewrite and fix U
'b Good. Further, the amount of fuel in addition 'r''<'411i) may be increased by narrowing the pulse width of the regular injection q.1 pulse, or by outputting an extraordinary injection pulse. Furthermore, only those that supply fuel with a fuel in valve are ``0'', which uses a carburetor.

(Effects of the Invention) As described above, the present invention stores the fuel increase value at the time of acceleration, and changes the amount of fuel C fuel jl',
Since the i digit value is rewritten and corrected, there are variations in performance between engines and changes over time, so b1 learning increases the above fuel Δ'jl and optimizes the t value, reducing the output drop during acceleration and the fuel efficiency. This can actually prevent 1ift.

[BRIEF DESCRIPTION OF THE DRAWINGS] Fig. 1 shows the entire device of the present invention 4':'i or Fig. 2 shows an embodiment (■Schematic diagram, Fig. 9'!3 to Fig. 6+a, flowchart). 1~. 1... Engine, 5... Gaso'301f'1 River valve,
22... Fuel 1 increasing means, 23... Acceleration detection means,
24... Storage means, 25... Air-fuel ratio fluctuation detection stage 1,
26...@Replacement means. Patent applicant Toyo Kogyo Co., Ltd. Figure 1-3, Figure 2 Figure 3 Figure 3 Figure 4 Figure 5 Figure 6

Claims (1)

[Claims] 1.] In a fuel control device for an engine equipped with a fuel increasing means for increasing the amount of fuel 1 in response to a detection signal from an acceleration detecting means when the carrot is accelerated, the fuel increasing value by the fuel increasing means is stored. Means and when accelerating? 11! an air-fuel ratio fluctuation detection means for detecting a drop in the fuel ratio; and a rewriting means for rewriting and correcting the fuel increase value stored in the storage means, which reduces the drop in the air-fuel ratio in response to the output of the detection means. The engine is characterized by having: δ tilt control g straight.