JP2846023B2 - Electronically controlled fuel injection device for internal combustion engine - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronically controlled fuel injection device for an internal combustion engine, and more particularly to an electronically controlled fuel that performs optimal air-fuel ratio control at the time of engine acceleration and improves operability of the engine. It relates to an injection device.

[Conventional technology]

As described in Japanese Patent Application Laid-Open No. 62-182453, the conventional apparatus sets the fuel increase at the time of engine acceleration by detecting the acceleration state of the engine based on the change amount of the operating state parameter and increasing the fuel amount according to the change amount. Was set.

[Problems to be solved by the invention]

The above prior art does not take into account the factors of the operating state before the start of acceleration of the engine, and particularly in the early stage of acceleration, an insufficient amount of fuel corresponding to the acceleration state of the engine is insufficient, and the air-fuel ratio becomes over lean. There was a problem that led to misfire.

It is an object of the present invention to prevent the air-fuel ratio from being over-lean by setting the fuel increase in consideration of the element of the operating state before the start of the acceleration during the acceleration operation of the engine, and to provide a favorable fuel supply system corresponding to the acceleration operation state of the engine. The purpose is to increase the amount of fuel.

[Means for solving the problem]

The object is to provide a fuel injection amount setting means for setting a fuel injection amount based on an operation state of an engine, an acceleration state detection means for detecting an acceleration state of the engine, and to set a fuel increase based on the detected acceleration state. Means for setting the fuel increase to be performed, calculating means for calculating the fuel injection amount based on the set fuel increase and the fuel injection amount, and driving for outputting an injection pulse signal corresponding to the calculated fuel injection amount to the fuel injection valve. An electronically controlled fuel injection device for an internal combustion engine provided with a pulse output means, comprising: an operating state storage means for storing at least a throttle valve opening; and a predetermined specific time before the acceleration is detected by the acceleration state detection means. Means for determining the initial value of the fuel increase based on the operating state before the specific time before the actual start of acceleration, and an acceleration state when the acceleration is detected. State and engine water temperature,
This is achieved by an electronically controlled fuel injection device for an internal combustion engine, comprising a correction means for correcting the initial value.

[Action]

Normally, the acceleration state of the engine is detected by detecting the parameters of the operating state, such as the throttle valve opening and the amount of change in the amount of air, and comparing the amount of change per unit time with a preset judgment level. I have. As for the parameters of the operating state, the dispersion from the latest value to a specific time before is always stored.

When the acceleration state is detected, the stored value before the specific time is determined to be the value at the start of acceleration, and the operating state parameters at that time, such as the engine speed, the throttle valve opening, the air amount, From the intake pipe pressure injection pulse signal and the like, a basic value for a preset fuel increase is searched and calculated. In addition, by detecting the acceleration, by calculating the increase amount of the acceleration increase according to the acceleration state or a coefficient of the increase amount,
The result calculated together with the basic value of the fuel increase is set as an initial value of the fuel increase. As a result, the amount of fuel injected can supply an appropriate air-fuel ratio during acceleration, so that the acceleration operation performance of the engine can be improved.

〔Example〕

 Hereinafter, an embodiment of the present invention will be described.

FIG. 1 is a system diagram of a fuel injection device embodying the present invention. The intake air amount of the engine is controlled by a throttle valve 2 and is input to a control unit 3. The opening of the throttle valve 2 is detected by a throttle sensor 5 and input to the control unit 3. A pulse corresponding to the crank angle detected by the crank angle sensor 7 is input to the control unit 3 and the engine speed is calculated based on the cycle of the pulse. Fuel is pumped from a fuel tank 8 by a fuel pump 9, and is supplied to an injection valve 10.
Injected from. FIG. 2 shows the control unit 3
Which comprises an arithmetic unit including a CPU, a RAM, a ROM, an A / D converter, and an input / output circuit.
Crank angle sensor 7, water temperature sensor 11, throttle sensor 5
A predetermined calculation is performed based on the input signal of (i), and the opening / closing pulse signal and timing of the injection valve 10 are controlled.

Next, a control method of the fuel injection valve according to the present invention will be described. FIG. 3 shows a means for detecting the acceleration state and the acceleration start state of the engine, which is performed by detecting a change amount ΔTH of the throttle valve per unit time of the throttle valve, for example, every 10 ms. Several setting determination levels corresponding to a sudden acceleration to a sudden acceleration for determining the acceleration state are provided in advance, and this is compared with ΔTH. At this time, when ΔTH first exceeds the setting determination level from the state of ΔTH = 0, the acceleration is detected. Further, the value of the throttle valve opening TH is always stored from the latest value to a value before a specific time, for example, 40 ms before, and the detection at the start of acceleration stores the value before the specific time from the detection of the acceleration. This is done by reading from the values that are present, and not only the throttle valve opening degree, but also the operating state parameters such as the engine speed, the air amount, the intake pipe pressure, and the injection valve pulse are stored and used as values before the start of acceleration. . FIG. 4 shows a method for obtaining a basic value TACI for the increased fuel amount from the operating state parameters before the start of acceleration. Among the parameters of the operating state, TACO is calculated by searching for an appropriate value from an appropriate amount configured in a map format by using a preset element, for example, the engine speed and the throttle opening TH, and calculating the TACO. At the same time the acceleration start before the injector pulse T _i, if T _i is the fuel Katsutoparusu obtains a correction coefficient T _FC had it occurred set to the engine coolant temperature. This is an element that compensates for an increase in the required correction amount in the case of acceleration from the middle of the fuel cut, in which the amount of wall flow adhering, etc., which is slightly present in the normal injection state, is eliminated. Calculated as above
Determine the basic amount of TACI from TACO and T _FC.

Next, FIG. 5 shows a method of obtaining an increase correction according to the acceleration state from the relaxation speed to the rapid acceleration detected by the acceleration detection. The correction amount corresponding to the acceleration state and the engine coolant temperature is retrieved from the table is set as a coefficient, computed as K _AC. From the results obtained as described above, TACC is finally calculated as an initial value for the fuel increase during acceleration.

FIG. 6 shows a state of the increase correction during the actual acceleration, in which the previously calculated TACC is controlled as an injection valve pulse signal. As for the injection timing, the fuel can be increased by any of an interrupt injection method in which the injection is performed at the time of detecting the acceleration and an increase injection method in which the injection is added to the normal injection timing. Thick even accelerated early in the time of engine acceleration for example rapid acceleration, no lack of conventional such fuel quantity, occurrence of misfire due to over-lean air-fuel ratio, is possible to prevent a drop in indicated mean effective pressure P _i it can.

Next, a block diagram of the present invention is shown in FIG. 7 and a flowchart is shown in FIG. At step 100 by Figure 8, enter the operating state parameters of the engine, the engine speed N, the air amount Q _a, the injection pulse T _i, updates the stored value until before a specific time from the respective latest values at step 101 I do. When acceleration is detected based on the throttle opening change amount ΔTH in step 103, the stored value obtained by the calculation in step 101 is read, and step 1 is executed.
Perform TACO calculations up to 06. Moreover, calculating the T _FC if preceding injection pulse T _i is the fuel Katsutoparusu by step 107, and finally calculates the TAC of step 109.

The injection pulse T _i calculated from Q _a and N is calculated in step 110 to be the latest value. In contrast another routine, has the operation of the injection timing, calculated in the routine, TAC, by T _i, at step 51, whether the interrupt injection, to determine the normal injection, the step 54 Te, the former case is when TAC + TS, the latter sets the T _i as the injection output pulse injection is started at the set point of the injection timing.

〔The invention's effect〕

According to the present invention, the fuel increase correction at the time of acceleration of the engine can be further added with an element in consideration of the operation state before the start of acceleration in addition to the element of the operation state in the acceleration state. Can prevent misfires caused by becoming over-lean.

Furthermore, when the engine is accelerated, the optimal fuel increase can be performed, and more precise air-fuel ratio control can be performed, so that acceleration performance and drivability can be improved.

[Brief description of the drawings]

FIG. 1 is a system diagram of the present invention, FIG. 2 is an input / output diagram of a control system, FIGS. 3 to 6 are explanatory diagrams of an embodiment of the present invention, FIG. 7 is a block diagram, and FIG. The figure is a flow chart. TH: Throttle valve opening, ΔTH: Throttle valve opening change, TACI: Increase basic amount, TAC: Increase initial value, Q _a
... air volume, N ... engine speed.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-61-1844 (JP, A) JP-A-62-87636 (JP, A) JP-A-59-93935 (JP, A) JP-A-62-1876 182453 (JP, A) JP-A-57-137631 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) F02D 41/00-41/40

Claims (1)

(57) [Claims] A fuel injection amount setting means for setting a fuel injection amount based on an operation state of the engine; an acceleration state detection means for detecting an acceleration state of the engine; and an increase amount of fuel based on the detected acceleration state. Setting means for setting a fuel increase to be set; calculating means for calculating a fuel injection amount based on the set fuel increase and the fuel injection amount; and outputting an injection pulse signal corresponding to the calculated fuel injection amount to the fuel injection valve. An electronically controlled fuel injection device for an internal combustion engine, comprising: a driving pulse output unit that performs at least an operation state storage unit that stores at least a throttle valve opening; and a predetermined identification that is performed when acceleration is detected by the acceleration state detection unit. Means for determining the initial value of the fuel increase based on the operating state before the specific time before the actual start of acceleration, and an acceleration state at the time of detecting the acceleration. An electronically controlled fuel injection device for an internal combustion engine, comprising: a correction unit that corrects the initial value based on a state and an engine coolant temperature.