JPS6123842A - Fuel injection device for engine - Google Patents

Abstract

PURPOSE:To improve a response and an accelerating feeling either, by performing engine control in discriminating an accelerating increment at actual running from that at idle running. CONSTITUTION:At a microcomputer 9, an engine speed is found by a detection signal out of a crank angle sensor 5, while a throttle opening and a throttle variation both are found by a detection signal out of a throttle sensor 4, and an air quantity is found by a detection signal out of an air flow meter 2 and that water temperature is found by a detection signal out of a water temperature sensor 3, respectively. On top of that, whether or not an engine is in time of actual running or at idle running is judged by a neutral switch 6, and when a fuel injection quantity is controlled with detection signals out of these sensors, such different accelerating compensation that an accelerating increment and an interstitial injection quantity are altered is carried out.

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD 1 The present invention relates to a fuel injection device for an automobile engine. [Prior Art] In an EGI system, the injection amount of a fuel injection valve (injector) is determined by engine operating status input signals from various sensors, switches, etc., and the basic injection m is the intake amount detected by an air 70-meter. It is determined by the amount of air and the rotational speed signal detected from the primary signal of the ignition coil. There is a delay in the detection of the air 70-meter (when the throttle valve is opened instantaneously during acceleration or when the engine is racing), and there is a difference between the amount of air that actually enters the engine and the amount of air detected by the air 70-meter, resulting in a change in the air-fuel ratio. (A'/F) becomes thin and lean). As a result, the acceleration feeling worsens, and especially in single point injection (SPI), the air-fuel ratio becomes even leaner due to the addition of the delay until the fuel injected by the injector is taken into the engine. Therefore, conventionally, a throttle sensor detects the throttle latch opening and clutch change amount, and based on this detection signal, the basic injection amount is multiplied by a coefficient corresponding to the above-mentioned delay to perform acceleration increase fl correction to prevent the air-fuel ratio from becoming lean. I am doing it. In addition, to improve the startup of engine speed,
Interrupt injection is performed in which a fixed amount of fuel is injected when the throttle is opened, regardless of the normal injection timing. These acceleration increase corrections and interrupt injections are carried out in 1. The correction and injection amount are determined using coefficients according to the throttle opening before acceleration (or dry cooking), throttle change amount, engine water temperature, engine speed before acceleration, and air amount before acceleration. This coefficient is determined in advance from experimental data and the like and is stored as data in the control unit. For example, Japanese Unexamined Patent Publication No. 55-46060 discloses a system that detects a change in the amount of incoming air during acceleration and supplies fuel corresponding to this amount of change to an injector. Also, JP-A-5
Japanese Patent Application No. 5-153830 discloses an apparatus in which the injection amount is determined based on a maximum value signal of the amount of incoming air.

[Problems to be solved by the invention]

Conventional acceleration correction of the basic injection amount does not allow appropriate injection amount control in the case of sudden changes in intake air amount during dry cooking and slow changes in intake air amount during acceleration during actual driving under load. . In other words, if the engine speed does not suddenly change, such as when driving under load, the delay between the actual air amount and the air amount calculated by the air flow meter will be small, and the acceleration increase correction coefficient and interrupt injection amount will be smaller. can be made smaller, but in dry cooking with no load, the engine speed changes suddenly, so the metering delay of the airflow meter increases, and the acceleration increase correction coefficient and interrupt injection amount must also be increased. It is extremely difficult to control them separately. In addition, it is better to increase the interrupt to improve response during dry cooking, and to decrease the acceleration increase and interrupt while driving due to exhaust gas regulations, but it is very difficult to control these separately.

[Means and actions to solve the problem]

The present invention provides injection control using various engine operating state detection signals obtained from an air flow meter, throttle sensor, water temperature sensor, engine rotation speed sensor, etc.
The present invention is characterized in that it determines whether the acceleration is idle or not based on the detection signal from the clutch switch or the neutral switch and the detection signal from the throttle sensor, and determines an appropriate acceleration increase correction coefficient ' and interrupt injection m in accordance with this determination. do.

【Example】

FIG. 1 is a configuration diagram of a fuel injection device showing one embodiment of the present invention. In the figure, an engine 1 injects fuel using a single point injection method, and an air meter 70-meter 2. Water temperature sensor 3. Throttle sensor 4. Crank angle sensor 5. A neutral switch 6 and a clutch sensor 1G are provided. Additionally, an 01 sensor 8 is provided for feedback control of the air-fuel ratio. The microcomputer 9 determines a fuel injection amount appropriate for the operating condition of the engine 1 according to the detection signals from these sensors and the SWIN≠, and controls the opening time of the injector 10. Also, the idle rotation control valve 11. EGR valve 7
, controls the fuel pump 12. In the figure, reference numeral 13 is a fuel tank, 14 is a pressure regulator, and 15 is an air cleaner. The microcomputer 9 determines the engine speed based on the detection signal of the crank angle sensor 5, the throttle opening and throttle change amount based on the detection signal of the throttle sensor 4, the air amount based on the detection signal of the air flow meter 2, and the water temperature sensor. The water temperature is determined based on the detection signal in step 3. In addition, a different acceleration correction is performed in which the neutral switch 6 determines whether the vehicle is running or if the vehicle is idle-cooked, and the acceleration increase amount J5 and the interrupt injection amount are changed when the injection amount is controlled based on the detection signal of the sensor. This correction will be explained according to the flowchart in FIG. The microcomputer 9 receives the detection signal from the neutral switch 6 (step 81) and determines whether or not the vehicle is running based on the detection signal (step 82). If you are driving, check the air flow meter 2. From the detection signals of sensors 3 to 5, the throttle opening before acceleration, the amount of change in the throttle angle,
Engine water temperature. Each data of the engine speed before acceleration and the amount of air before acceleration is obtained (step S3), and based on these data, the acceleration increase correction coefficient and interrupt injection amount during driving are determined from the table data of the acceleration correction machine (step S3). S4), multiply this coefficient by the basic injection amount to obtain the acceleration increase m value (step S5),
Further, the interrupt injection amount is determined (step S6), and the injector 10 is
control the injection amount. On the other hand, when determining dry cooking (step 82), the microcomputer 9 controls the air flow meter 2. The acceleration increase correction coefficient and the interrupt injection coefficient are calculated from the table data of the acceleration correction (■) in dry cooking for the detection signals from each sensor 3 to 5 (step 88).
Step 39) Using this coefficient, the acceleration increase value and the interruption injection interval are determined in steps 85 to S7 to control the injection [t] of the injector. Here, acceleration correction 1 and acceleration correction ■ have different coefficients,
Acceleration correction (■) reduces the acceleration increase correction and interrupt injection amount to prevent the air-fuel ratio from becoming lean during driving when the engine speed does not change rapidly. On the other hand, the acceleration correction (3) increases the acceleration amount correction and the split injection amount to prevent the air-fuel ratio from becoming lean during dry cooking where the engine speed changes rapidly. Note that determining whether the vehicle is running or not is achieved by using a clutch switch that detects the opening and closing of the clutch in cars that have a clutch. [Effects of the Invention] According to the present invention, since the acceleration increase m or interrupt injection amount m during driving is controlled in a manner that distinguishes between the acceleration increase m or interrupt injection amount m during running and the acceleration increase m or interrupt injection amount m during dry cooking, the It has the effect of increasing the amount to improve response, and reducing the amount of increase during driving to improve acceleration feeling. In addition, since the correction is carried out by distinguishing between dry cooking and driving, the control reduces harmful exhaust gas emissions (1) by appropriately increasing the amount due to dry heating and driving.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram showing one embodiment of the present invention, and FIG.
It is an acceleration correction flowchart of the microcomputer shown in the figure. 1... Engine, 2... Air 70-meter, 3...
・Water wetness sensor, 4... Throttle sensor, 5... Crank angle sensor, 6... Neutral switch, 7.
... EGR valve, 8... O2 sensor, '9... Microcomputer, 10... Injector, 11.
... Idle speed control pulp, 12... Fuel pump, 13... Fuel tank, 14... Pressure regulator, 15... Air cleaner.

Claims (1)

[Claims] A fuel injection device that controls the amount of injection from a fuel injection valve based on an engine operating state detection signal, and determines whether it is accelerating or idling based on a detection signal from a clutch switch or neutral switch and a detection signal from a throttle sensor. A fuel injection device for an engine, comprising control means for reducing the acceleration increase correction of the injection amount and the interrupt injection amount, and for increasing the acceleration increase correction and the interruption injection amount in case of a dry blow.