JPH06346770A - Fuel injection control device - Google Patents

Abstract

PURPOSE:To improve a fuel consumption rate and exhausted harmful component value by correcting the invalid injection time of a fuel injection valve according to the sharing condition of an electric load in an internal combustion engine, when the fuel injection amount of an internal combustion engine is controlled in a fuel injection time calculated on the basis of a prescribed element. CONSTITUTION:In an internal combustion engine 2, at least a fuel injection valve 14 is arranged while directing toward a combustion chamber 10. The fuel injection valve 14 is controlled by a control unit 40. Namely, in the control unit 40, an air amount, an engine rotational speed, and the like picked up by several kinds of sensors 26 to 38 for detecting respectively operating condition in the internal combustion engine 2 are detected as fuel injection timing calculating elements. In this case, in the control unit 40, the invalid injection timing of the fuel injection valve 14 is corrected according to sharing condition of an electric load generated by operation of an electric load apparatus 46 in the internal combustion engine 2. It is thus possible to correct the invalid injection timing of the fuel injection valve 14 properly to supply a required fuel injection amount so as to ensure a proper air-fuel ratio.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel injection control device, and more particularly, it can appropriately correct an invalid injection time of a fuel injection valve to supply a required fuel injection amount to secure an appropriate air-fuel ratio. The present invention relates to a fuel injection control device capable of improving a fuel consumption rate and a harmful exhaust gas component value.

[0002]

2. Description of the Related Art Some internal combustion engines mounted on vehicles or the like are equipped with a fuel injection control device for supplying fuel from a fuel injection valve. The fuel injection control device detects the intake air amount of the internal combustion engine, the engine speed, etc. as a fuel injection time calculation element, and drives the fuel injection valve by the fuel injection time calculated from the fuel injection time calculation element to drive the internal combustion engine. Control the injection amount of the fuel supplied to.

The fuel injection valve of the fuel injection control device behaves as shown in FIG. The fuel injection valve has a fuel injection time t
When the injection pulse of i is input, the valve opening delay time to until the valve is completely opened, the valve closing delay time tc until the valve is completely closed, and the valve opening bounce time Tb and the valve closing when the valve is opened. A behavior with a valve closing bounce time Tb ′ of time occurs.

Further, the fuel injection time ti of the injection pulse supplied to the fuel injection valve and the fuel injection amount Q have a relationship as shown in FIG. Since the fuel injection valve has the valve opening delay time to until the valve is completely opened with respect to the injection pulse of the fuel injection time ti that is input, the fuel injection valve is delayed by tv from the start of input of the injection pulse. Inject. This delay tv is the invalid injection time. The total injection amount of the fuel injection valve is determined by this invalid injection time tv.

The invalid injection time tv changes depending on the battery voltage. The solid line in FIG. 9 is the invalid injection time tv when the battery voltage is normal. The broken line in FIG. 9 is the invalid injection time tv ′ when the battery voltage drops. Therefore, the invalid injection time tv is changed and set by the voltage as shown in FIG.

[0006]

By the way, as shown in FIG. 11, when an electric load is applied to the internal combustion engine, the voltage drops. In this case, the alternator operates at the moment when the electric load is applied, and power is supplied from the battery until the voltage reaches a normal value, so that the voltage drops abnormally. In particular, when the radiator fan operates as an electric load, the initial voltage drop becomes large.

Therefore, the fuel injection valve has a disadvantage that the ineffective injection time becomes longer due to the voltage drop due to the load of the electric load, the required fuel injection amount cannot be supplied, and the air-fuel ratio becomes thin. Further, the fuel injection valve has a disadvantage that the fuel injection amount is greatly reduced and an overshoot occurs when another electric load is additionally added while the electric load is added.

As a fuel injection control device for coping with such an inconvenience, there are those disclosed in JP-A-58-28537 and JP-A-61-190145. The fuel injection control device disclosed in Japanese Patent Application Laid-Open No. 58-28537 corrects the fuel injection time when the internal combustion engine is started according to the intake air amount and the battery voltage. JP-A-6
The fuel injection control device disclosed in Japanese Patent Laid-Open No. 1-190145 corrects the invalid injection time according to the time from the start time of energization of the ignition coil to the start time of energization of the fuel injection valve.

However, the fuel injection control devices disclosed in these publications have a disadvantage that the fluctuation of the invalid injection time due to the state of the load of the electric load cannot be sufficiently corrected. Also,
The invalid injection time is affected not only by the electric load but also by the change in the engine speed. In consideration of these factors, it is desired to realize a fuel injection control device capable of appropriately correcting the invalid injection time.

[0010]

SUMMARY OF THE INVENTION In order to solve such inconvenience, the present invention drives a fuel injection valve by the fuel injection time calculated from a fuel injection time calculation element to supply the fuel to an internal combustion engine. In the fuel injection control device for controlling the injection amount of fuel, the control means is provided for controlling to correct the invalid injection time of the fuel injection valve according to the electric load bearing state of the internal combustion engine. Further, the present invention is a fuel injection control device for controlling the injection amount of fuel supplied to an internal combustion engine by driving a fuel injection valve according to a fuel injection time calculated from a fuel injection time calculation element,
It is characterized in that a control means is provided for controlling to correct the invalid injection time of the fuel injection valve according to the electric load bearing state of the internal combustion engine and the engine speed.

[0011]

According to the structure of the present invention, the fuel injection control device controls the electric load by the control means so as to correct the invalid injection time of the fuel injection valve according to the electric load bearing state of the internal combustion engine. It is possible to appropriately correct the invalid injection time of the fuel injection valve according to the supporting state of Also,
The present invention controls the fuel injection valve so as to correct the invalid injection time in accordance with the electric load bearing state and the engine speed change state of the internal combustion engine, so that the fuel is fed depending on the electric load bearing state and the engine speed. The invalid injection time of the injection valve can be corrected more appropriately.

[0012]

Embodiments of the present invention will now be described in detail with reference to the drawings.

1 to 4 show an embodiment of the present invention. In FIG. 4, 2 is an internal combustion engine, 4 is an intake passage, and 6 is an exhaust passage. The internal combustion engine 2 is provided with an air cleaner 8 at the upstream end of the intake passage 4 and communicates the downstream end with a combustion chamber 10 of the internal combustion engine 2. A throttle valve 12 is provided in the middle of the intake passage 4. Further, the internal combustion engine 2 has an exhaust passage 6 communicating with the combustion chamber 10.
The internal combustion engine 2 is provided with a fuel injection valve 14 facing the combustion chamber 10. The fuel injection valve 14 injects fuel supplied from a fuel tank (not shown).

The internal combustion engine 2 includes a throttle valve 1
A bypass passage 16 that bypasses 2 and communicates with the intake passage 4 is provided. The bypass passage 16 is provided with an idle speed control valve 18 that is feedback-controlled so that the engine speed becomes a target speed during idle operation of the internal combustion engine 2.

Further, the internal combustion engine 2 is provided with an air valve 20 which is operated by the cooling water temperature and supplies air to the intake passage 4 on the downstream side of the throttle valve 12. The air valve 20 increases the amount of air supplied to the internal combustion engine 2 at the time of cold start, and raises the engine speed higher than the idle speed to bring the engine into the first idle operation state.

Further, the internal combustion engine 2 is provided with an ignition coil 22 for causing an ignition plug (not shown) to fly, and a distributor 24 for distributing to the ignition plug of each combustion chamber.

The internal combustion engine 2 includes a throttle valve 1
2, an idle switch 26 for detecting the fully closed state, an intake air temperature sensor 28 for detecting the intake air temperature, a pressure sensor 30 for detecting the intake pressure, a water temperature sensor 32 for detecting the cooling water temperature, and a rotation angle sensor 34. A speedometer 36 and an O2 sensor 38 are provided to input a vehicle speed signal. The rotation angle sensor 34 is provided in the distributor 24.

These various sensors 26 to 38 are connected to the input side of a control section 40 which is a control means constituting the fuel injection control device. Further, on the input side of the control unit 40, CO
A CO adjustment resistor 42 for inputting an adjustment signal, and an air conditioning switch 44 for inputting a drive signal of an air conditioner (not shown).
The electric load device 46 and the battery 48 are connected to input an electric load signal due to the operation of a radiator fan, a headlight, a stop lamp, or the like.

At the output side of the control unit 40, the fuel injection valve 14, the idle speed control valve 18, and the ignition coil 22 are provided.
And are connected.

The control unit 40 detects the air amount, the engine speed, etc. as a fuel injection time calculation element by the various sensors 26 to 38, calculates the fuel injection time from this fuel injection time calculation element, and outputs the fuel injection time to the fuel injection valve 14. The drive signal is output to cause the internal combustion engine 2 to inject fuel. Further, the control unit 40 outputs an ignition command signal to the ignition coil 18 to cause a spark plug (not shown) to fire, and the idle speed control valve 18 is controlled so that the engine speed during idle operation becomes the target speed. Is feedback-controlled to adjust the amount of bypass air in the bypass passage 16.

In such a fuel injection control device, the control unit 40 controls to correct the invalid injection time Tv of the fuel injection valve 14 in accordance with the state of load of the electric load due to the operation of the electric load device 46. Is.

Next, the operation will be described.

The internal combustion engine 2 has a throttle valve 12
The fuel injected by the fuel injection valve 14 is supplied together with the air adjusted by, and is ignited by a spark plug (not shown) and burned. The fuel injection amount of the fuel injection valve 14 is appropriately controlled by the control unit 40.

The control unit 40 uses signals input from the various sensors 26 to 38 as fuel injection time calculation elements, calculates the fuel injection time ti from the fuel injection time calculation elements, and outputs a drive signal to the fuel injection valve 14. To inject fuel. Further, the control unit 40 outputs an ignition command signal to the ignition coil 18 to cause a spark plug (not shown) to fire, and the idle speed control valve 18 is controlled so that the engine speed during idle operation becomes the target speed. Feedback control.

The control unit 40 controls the fuel injection valve 14 according to the state of load of the electric load caused by the operation of the electric load device 46.
The invalid injection time Tv is controlled to be corrected.

More specifically, the control unit 4 of the fuel injection control device.
0 starts control as shown in FIG. 1 (step 10
Then, it is judged whether or not the electric load signal is ON by the operation of the electric load device 46 (step 102).

The electric load is supported by the operation of the electric load device 46 (step 102: YE).
In the case of S), the invalid injection time correction value TVEL is set to a minus value (TVEL = -a) of the correction coefficient a, and the invalid injection time return coefficient b is added to this TVEL every time the invalid injection time correction return time t elapses ( TVEL = TVEL + b), and the invalid injection time correction value TVEL becomes "0" by this addition (TVEL = 0)
The process up to (step 104) is performed.

That is, in step 104, the initial value of the invalid injection time correction value TVEL is set to TVEL = -a, and the invalid injection time return coefficient b is set every time the invalid injection time correction return time t elapses at this TVEL = -a. Every time the invalid injection time correction recovery time t elapses, new TVEL = TVEL
The invalid injection time correction value TVEL is set to "0" in the processing for obtaining + b.
Until (TVEL = 0).

Then, the current invalid injection time Tv is added to the invalid injection time correction value TVEL obtained by the gradual update in step 104 to obtain a new invalid injection time Tv (step 106), and the end (Step 1
08) (see FIG. 3).

In step 102, when the electric load is not loaded because the electric load device 46 is not operated (step 102: NO), the invalid injection time correction value TVEL is TVEL = 0 (step 11).
0), the invalid injection time correction value TVEL set to "0" is added to the current invalid injection time Tv to obtain a new invalid injection time Tv (step 106), and the process ends (step 108). .

Ineffective injection time Tv obtained by the above process
Is used to calculate the fuel injection time ti. The fuel injection time ti includes the invalid injection time Tv that is corrected according to the load bearing state of the electric load, so that the required fuel injection amount can be supplied.

That is, in this fuel injection control device, on condition that the electric load device 46 such as a radiator fan is operated and the electric load is added, as shown by the solid line in FIG. Since the setting of the invalid injection time becomes large due to the large decrease, the electric load device 4
The load of the electric load due to the operation of the electric load device 46 is detected by using the operation switch of No. 6 or the like, and the invalid injection time is corrected.

As a result, from the time when the electric load is applied until the time when the alternator (not shown) operates and the voltage returns to the normal value, as shown by the broken line in FIG. Can be set.

Therefore, even if an electric load is added as shown in FIG. 3 by setting an appropriate invalid injection time,
The required fuel injection amount can be supplied. As a result, it is possible to prevent the air-fuel ratio from becoming thin, to ensure an appropriate air-fuel ratio, and to improve the fuel consumption rate and the exhaust gas harmful component value by ensuring this appropriate air-fuel ratio. Further, this fuel injection control device can be dealt with only by changing the program of the control unit 40 without requiring addition / addition of parts, and can be implemented cost effectively.

As shown in FIG. 3, the invalid injection time is corrected only after the electric load is applied until the alternator (not shown) operates and the voltage returns to the normal value. That is, as shown in steps 104 and 106, the initial value for setting an appropriate invalid injection time by correction is TVEL =
−a, and the invalid injection time correction recovery time b is added to this TVEL = −a every time the invalid injection time correction recovery time t elapses, and new TVEL = TVEL + b is added each time the invalid injection time correction recovery time t elapses. Is performed until the invalid injection time correction value TVEL becomes “0” (TVEL = 0), and the invalid injection time correction value TVEL obtained by gradually updating the invalid injection time Tv is added to obtain a new invalid value. By performing the process of obtaining the injection time Tv, the invalid injection time is made to approach the basic setting from "-a" only until the alternator operates and the voltage returns to the normal value after the electric load is added. By gradually correcting, the invalid effect injection time can be appropriately corrected.

FIG. 5 shows another embodiment of the present invention. In this embodiment, the invalid injection time is corrected according to the state of load of the electric load.

In this alternative embodiment, a radiator fan, a headlight and a stop lamp are provided as the types of electric load equipment, and the electric load signal S1 of the radiator fan is provided.
The correction coefficient a1, the electric load signal S2 of the headlight and the correction coefficient a2, the electric load signal S3 of the stop lamp and the correction coefficient a3 are set. Each correction coefficient is a1>
The relationship of a2> a3 is set.

In this alternative embodiment, the control unit 40 allows
Control is performed so as to correct the invalid injection time Tv of the fuel injection valve 14 according to the load states of various electric loads.

More specifically, the control unit 4 of the fuel injection control device.
0, control starts as shown in FIG. 5 (step 20
Then, it is judged whether the electric load signal S1 is ON (step 202).

The electric load is supported by the operation of the radiator fan (step 202: YE).
S), the correction coefficient a is a = a1 (step 204)
And Next, the invalid injection time correction value TVEL is set to a negative value of the correction coefficient a1 (TVEL = -a1), and this TVEL
Each time the invalid injection time correction return time t elapses, the invalid injection time return coefficient b is added (TVEL = TVEL + b), and this addition causes the invalid injection time correction value TVEL to become “0” (TVE
Processing (step 206) is performed until L = 0).

That is, in step 206, the initial value of the invalid injection time correction value TVEL is set to TVEL = -a1,
The invalid injection time correction coefficient b is added to this TVEL = -a1 every time the invalid injection time correction recovery time t elapses, and a new TVEL = T is obtained each time the invalid injection time correction recovery time t elapses.
The process of obtaining VEL + b is performed until the invalid injection time correction value TVEL becomes "0" (TVEL = 0).

Next, a process (step 208) of adding the invalid injection time correction value TVEL obtained by the gradual updating in step 206 to the new invalid injection time Tv to obtain a new invalid injection time Tv is performed, and the process is ended. (Step 2
10).

When the step 202 is NO, it is judged whether or not the electric load signal S2 is ON (step 21).
2) Do.

Since the headlight is turned on, an electric load is added (step 212: YES).
In this case, the correction coefficient a is set to a = a2 (step 214), and the correction coefficient a2 is used to execute the step 20 as described above.
The processing from 6 to step 210 is performed.

When the step 212 is NO, it is judged whether or not the electric load signal S3 is ON (step 21).
6) Do.

Since the stop lamp is turned on, an electric load is added (step 216: YE).
S), the correction coefficient a is a = a3 (step 218)
Then, the correction coefficient a2 is used to perform the step 2
The processing from 06 to step 210 is performed.

When the step 216 is NO, since the electric load is not added, the invalid injection time correction value TVEL is set to TVEL = 0 (step 220), and the invalid injection time Tv is set to "0". Injection time correction value TVEL
Is added to obtain a new invalid injection time Tv (step 208), and the process ends (step 210).

Invalid injection time Tv obtained by the above process
Is used to calculate the fuel injection time ti. The fuel injection time ti includes the invalid injection time Tv that is corrected according to the load bearing state of the electric load, so that the required fuel injection amount can be supplied.

That is, in this other embodiment, the condition is that the radiator fan is actuated and the headlights / stop lamps are turned on to load the respective electric loads.
The invalid injection time is corrected according to the magnitude of the electric load.

As a result, according to this other embodiment, the same effect as that of the above-mentioned embodiment can be obtained, and more appropriate invalid injection time can be set according to the magnitude of the electric load.

Therefore, according to this embodiment, a more appropriate invalid injection time can be set according to the magnitude of the electric load, so that the required fuel injection amount can be more reliably supplied. A more appropriate air-fuel ratio can be secured, and the fuel consumption rate and the harmful exhaust gas component value can be improved.

The fuel injection control device is not limited to the above embodiment. As shown in FIG. 6, the correction coefficient a can be set according to the engine speed N. That is, in the engine speed N1 and the engine speed N2 in the relationship of N1 <N2, when an electric load such as a radiator fan is added, the engine speed is higher than that at the engine speed N1 as shown in FIG. The voltage drop is smaller when the number is N2.

Therefore, the correction coefficient a relating to the engine speed N can make the value of the engine speed N2 smaller than the value of the engine speed N1. Therefore, as shown in FIG. 6, the correction coefficient a can be set to decrease as the engine speed N increases.

The correction coefficient a set according to the engine speed N can be used in combination with the configuration shown in FIG. 5 for correcting the invalid injection time according to the magnitude of the electric load. That is, the correction coefficient a1 of the radiator fan, the correction coefficient a2 of the headlamp, and the correction coefficient a3 of the stop lamp are set according to not only the magnitude of the electric load but also the engine speed N, and the invalid injection time is set by these correction coefficients. By the correction, the invalid injection time can be corrected according to the electric load bearing state of the internal combustion engine 2 and the engine speed.

Therefore, the more appropriate invalid injection time can be set according to the magnitude of the electric load and the engine speed, so that the required fuel injection amount can be more reliably supplied, and a more appropriate empty space can be supplied. The fuel ratio can be secured, and the fuel consumption rate and the exhaust gas harmful component value can be improved.

[0056]

As described above, according to the present invention, the fuel injection control device can appropriately correct the ineffective injection time of the fuel injection valve according to the load bearing state of the electric load and the engine speed. Therefore, it is possible to supply the required fuel injection amount,
It is possible to secure an appropriate air-fuel ratio and improve the fuel consumption rate and the exhaust gas harmful component value. Further, the fuel injection control device of the present invention can be dealt with only by changing the program of the control means without requiring addition / addition of parts, and can be implemented cost effectively.

[Brief description of drawings]

FIG. 1 is a flowchart of correction of an invalid injection time by a fuel injection control device showing an embodiment of the present invention.

FIG. 2 is a diagram showing a relationship between a reactive injection time and a reactive injection time with and without an electric load.

FIG. 3 is a diagram showing a relationship among an electric load, a voltage, a reactive injection time correction value, a reactive injection time, and an air-fuel ratio.

FIG. 4 is a schematic configuration diagram of a fuel injection control device.

FIG. 5 is a flow chart of correction of an invalid injection time showing another embodiment of the present invention.

FIG. 6 is a diagram showing a relationship between an engine speed and a correction coefficient.

FIG. 7 is a diagram showing the relationship between the engine speed and the invalid injection time.

FIG. 8 is an explanatory diagram of invalid injection time.

FIG. 9 is a diagram showing a relationship between a fuel injection time and an invalid injection time with respect to a fuel injection amount.

FIG. 10 is a diagram showing a relationship between voltage and reactive injection time.

FIG. 11 is a diagram showing a relationship among an electric load, a voltage, a reactive injection time, and an air-fuel ratio.

[Explanation of symbols]

 2 Internal combustion engine 4 Intake passage 6 Exhaust passage 10 Combustion chamber 12 Throttle valve 14 Fuel injection valve 26 Idle switch 28 Intake temperature sensor 30 Pressure sensor 32 Water temperature sensor 34 Rotation angle sensor 36 Speed meter 38 O2 sensor 40 Control section 42 CO adjustment resistance 44 Air Conditioning Switch 46 Electric Load Equipment 48 Battery

Claims (2)

[Claims] 1. A fuel injection control device for controlling an injection amount of fuel supplied to an internal combustion engine by driving a fuel injection valve according to a fuel injection time calculated from a fuel injection time calculation element, wherein an electric load of the internal combustion engine is provided. A fuel injection control device comprising control means for controlling the invalid injection time of the fuel injection valve in accordance with the supporting state. 2. A fuel injection control device for controlling an injection amount of fuel supplied to an internal combustion engine by driving a fuel injection valve according to a fuel injection time calculated from a fuel injection time calculation element, wherein an electric load of the internal combustion engine is provided. A fuel injection control device comprising a control means for controlling to correct the invalid injection time of the fuel injection valve according to a supporting state and an engine speed.