JPS62165547A - Intake air quantity adjustment system in electronic type fuel injection device - Google Patents

Abstract

PURPOSE:To enable smooth acceleration without any shock by closing an air control valve within a bypass passage formed bypassing a throttle valve at the time of acceleration from an idling condition, and opening gradually said valve in the course of predetermined time. CONSTITUTION:An electronic type fuel injection device operates fuel injection pulse band in the control unit 14 thereof according to an intake air quantity obtainable from an air flow meter 5, the number of engine revolutions from the output signal of an ignition coil 13 and the like, and controls an injector 8 for each cylinder. Also, said device controls an air control valve 18 in way of a bypass passage bypassing a throttle valve 2, depending upon an engine operation condition, thereby regulating an air intake air quantity. In this case, when acceleration from an idling condition has been detected in the control unit 14, the valve 18 is made to close and then gradually open in the course of predetermined time, thereby restraining a drive power fluctuation and alleviating an acceleration shock.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to an intake air amount adjustment method in an electronic fuel injection device.

[Conventional technology]

For fuel injection engines, for example, Japanese Patent Application Laid-Open No. 54-7492
As shown in Publication No. 4, the fuel injection tWffi is determined by correcting the calculated values of the intake air l measured by an air flow meter and the engine speed. Therefore, when the vehicle is coasting, the amount of intake air is small when the opening is at idle, and when the accelerator is then pressed to accelerate again, the amount of intake air suddenly increases as the opening of the accelerator increases. It will increase. At this time, there was a problem in that the driving force suddenly changed as shown by the dotted line in Fig. 4, and the driver felt a shock. Conventionally, as a countermeasure against this problem, the depression stroke of the accelerator pedal is lengthened (or the shape of the throttle cam is specified to have unequal speed), and the opening operation of the throttle valve is adjusted to a certain degree in response to the movement of the accelerator pedal. certain section,
A method has been proposed in which the sensitivity is reduced to smooth changes in the driving force as well as the amount of intake air.

[Problem to be solved by the invention 1 However, increasing the stroke of the accelerator pedal
11iIi Due to mounting restrictions, and if the shape of the throttle cam is specified to be one that increases the unequal speed, the problem arises that the pedal depression force is too light at the beginning of pedal depression and too heavy at the end. Additionally, there are problems such as deterioration of durability due to swinging of the accelerator cable. The present invention has been made based on the above circumstances, and in this type of fuel injection amount control, a bypass path is provided to the throttle chamber, and the air amount is controlled via an air control valve in addition to the main intake air amount. This paper aims to provide an intake air 1t1411 method for an electronic fuel injection device that can reduce the shock in the transient state that occurs when reaccelerating during coasting with the accelerator released. . [Means for Solving the Problems] To this end, the present invention bypasses the amount of intake air supplied via the throttle chamber through an air control valve controlled by factors such as engine speed. The air control valve is supplied to the intake system together with the amount of air from the road, and the opening degree of the air control valve is controlled during acceleration from an idle state, and the amount of intake air is reduced in accordance with changes in the duty value. .

[For production]

According to such a system, by substantially closing and gradually opening the bypass path, the overall intake air amount is controlled to be reduced only when accelerating from an idle state, and the drive force in response to accelerator depression is controlled to be reduced. It suppresses the increase in force, eliminates shock, and provides smooth control characteristics.

【Example】

Hereinafter, one embodiment of the present invention will be specifically described with reference to the drawings. In FIG. 1, to explain the case where the present invention is applied to a horizontally opposed four-cylinder multi-point fuel injection engine, reference numeral 1 denotes a throttle body having a throttle valve 2. The intake pipe 3 communicates with an air flow meter 5 immediately downstream of the air cleaner 4. The downstream side of the throttle body 1 communicates with an engine main body 7 via an intake manifold 6, and an injector 8 is attached to each of the first to fourth cylinders in the engine main body 7. The fuel system leading to the injector includes a circulation path 12 that returns to the fuel tank 9 again via the fuel tank 9, the fuel pump 10, the injector 8, the intake manifold 60, and the pressure regulator 11 that opens and closes under negative pressure. The fuel pressure is always maintained at a constant value higher than the intake manifold internal pressure, and the fuel injection port is controlled by the injection time. Then, the amount of intake air measured by the airflow meter 5 and the ignition pulse signal from the ignition coil 13 according to the engine speed are input to the control unit 14 to calculate the injection time, etc. - The injector 8 is operated by the injection signal from the unit 14. In the figure, reference numeral 15 is a throttle switch, 16 is a water temperature sensor, 17 is a vehicle speed sensor, and 18 is an air control valve. And fuel injection IJ! Regarding ffi control 1 (l),
The intake air amount is calculated based on the air flow meter 5 and the engine rotation speed calculated in the control unit 14 based on the signal from the ignition coil 13. Then, the basic fuel injection pulse width is calculated. In addition, the warm-up state of the engine is detected by the water temperature sensor 16, and this is incorporated into the above-mentioned calculation result of the basic fuel injection pulse width as a signal of the correction element, and correction is performed to obtain the appropriate injection pulse width. . On the other hand, in the case of re-acceleration during coasting, calculations are performed within the control unit 14 using a control system as shown in FIG. That is, based on signals from the ignition coil 13, throttle switch 15, and vehicle speed sensor 17, the engine rotation speed calculation circuit 19 and the predetermined time setting circuit 2
0, a predetermined calculation is performed in the vehicle speed reading circuit 21, and these signals are read as 1 in the rscontr duty determining circuit 22.
combined into one control signal to drive the driving means 23;
Controls the air control valve 18. The arithmetic expression in the above-mentioned TSContr duty determination circuit 22 is as follows. l5OOn-[ISCtw+ l5Cac+ fscf
fac+l5Cfb (or TSCfb+1) ] −
l5Oontr... (1) Here, in equation (1), l5OOn is the output duty, ISCtw is the basic duty, l5CaC is a correction component during operation of the air conditioner (air conditioner), not shown.
l5Cffac is a correction component when starting the air conditioner, I
SCl OJ:'CF I 5Cfb+1 Each feedback correction component when the fly controller is OFF and ON, (3(:, ontr is the correction component when the throttle valve 2 changes from OFF to ON. The above-mentioned feedback correction component is a correction that should be fed back to the target rotational speed, and the only factor is the rotational speed, which is made different depending on when the air conditioner is turned on and when it is turned off. Feedback is provided only at the idle speed.Then, in the duty determining circuit 22, the above (1)
The basic condition of the formula, A-[ISCtw+ l5Cac+l
S Cffac+ I S Cl (or l5Cfb
+1 ) ], when the throttle valve 2 is activated (the accelerator pedal is depressed), the air amount is corrected based on factors such as the depression level of the throttle valve 2 and the depression change m1 water temperature. At this time, l 3 Contr is determined by whether or not acceleration control is performed from an idle state. Under this condition, the driving means 23 is driven, the air control valve 18 is closed by a predetermined opening, and then gradually opened. Become. Therefore, when accelerating from a start or when coasting, the amount of intake air from the bypass path is gradually reduced over a predetermined period of time, as shown in Figure 3, so that the amount of air intake from the bypass path decreases rapidly, even though the number of accelerator pedal fleas increases. As shown by the solid line in FIG. 4(b), the change in driving force becomes smaller, and the shock during acceleration becomes smaller. Next, the control of the air control valve 18 will be specifically explained with reference to the flowchart shown in FIG. First, in step S1, it is determined whether the idle switch (throttle switch) is OFF. If it is not OFF, it is in the idle state, so step S
If the OFF flag is set to -0 in step 2 and the vehicle is in a non-idle state, it is determined whether the OFF flag is -1 or not in step S3. OFF when accelerated from idle state
Since the flag is O, the determination result is No, and the process moves to step S4, where the OFF flag is set to -1. Next, in step S5, I S C0ntr is set to an initial value. Further, if the OFF flag is -1 in step S3, it is determined in step S6 whether or not 13CONtr-0,
If YES, skip step S7; if NO, proceed to step S7 and set l5Contr-I S Contr -1
Perform the calculation. In this way, when the above program is completed, normal control of the ISC is entered in step S8, and in steps 39 and 310, I S Con - I S Co
It executes the calculation of n-I S Contr and the output of l5OOn.

【Effect of the invention】

The present invention has been described in detail above, and the air control valve is closed when accelerating after idling, and then gradually opened during a predetermined period of time, so that when accelerating from northward or coasting, the air control valve is closed. Air supply control is performed to avoid shocks and achieve smooth acceleration without increasing the driving force suddenly in response to changes in throttle opening.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention, FIG. 2 is a control system diagram, and FIG. 3 is a diagram showing changes in intake air amount according to the present invention.
FIG. 4 is a diagram showing changes in driving force during acceleration from coasting corresponding to the same throttle opening, and FIG. 5 is a flowchart explaining the operation. 1... Throttle body, 2... Throttle valve, 3
... Intake pipe, 4... Air cleaner, 5... Air flow meter, 6... Intake manifold, 7... Engine body, 8... Injector, 9... Fuel tank,
10...Fuel pump, 11...Regulator, 12
...Circulation system path, 13...Ignition coil, 14...Control unit, 15...Throttle switch, 16...Water temperature sensor, 17...Vehicle speed sensor, 18
... Air control valve, 19... Engine rotation speed calculation circuit, 20... Predetermined time setting circuit, 21...
- Medium speed reading circuit, 22... ISC duty determining circuit, 23... Driving means. Figure 2 Figure 3 n~ Time Figure 4 Time

Claims (1)

[Claims] A system that supplies the amount of intake air supplied via a throttle chamber to the intake system together with the amount of air from a bypass path via an air control valve that is controlled by factors such as engine speed. An intake air amount adjustment method in an electronic fuel injection device, characterized in that an air control valve is closed to block air from a bypass path during acceleration from an idling state, and then gradually opened during a predetermined period of time.