JPS61123729A - Fuel injection quantity controller for internal-combustion engine - Google Patents

Abstract

PURPOSE:To prevent an air-fuel ratio from becoming too much overrich as well as to keep off a misfire and a drip in engine output, by constituting a compensation value for compensating a fundamental fuel injection quantity for increment in time of high load running of an engine, so as to be set according to a warming state of the engine. CONSTITUTION:An output signal of a sunning state detecting device M2 detecting those of suction pipe pressure, engine speed, air-fuel ratio, etc., is inputted and a fundamental fuel injection quantity Tp is calculated by a fundamental fuel injection quantity calculating device M3 according to the detected running state. This fundamental fuel injection quantity Tp is made so as to perform output increment compensation when high load running is detected by a high load running detecting device M4 and also to perform warming-up increment compensation when warming up is detected by a warming-up state detecting device M5 at an actual fuel injection quantity calculating device M6 each. In this case, an output increment compensation value to be used in time of high load running of an internal-combustion engine M1 is constituted so as to be set according to a warming-up state of the said engine M1 by an output increment compensation value setting device M7.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a fuel injection amount control device for an internal combustion engine, and more specifically, the present invention relates to a fuel injection amount control device for an internal combustion engine. Internal combustion engine fuel injection ffi $
11 all device.

[Prior Art] Conventionally, there has been an electronically controlled fuel injection If ffi 11 till device that detects the operating state of an internal combustion engine and determines the fuel injection amount of the internal combustion engine according to the operating state. In this type of fuel injection amount control device, the basic fuel injection amount is determined based on the engine's intake pipe pressure, engine speed, intake air amount, etc., and during high load operation of the internal combustion engine such as during acceleration, Its basic twist jet! )1m output increase correction to increase the line-to-line output, or when the engine is cold or cold, so-called warm-up operation of the internal combustion engine, the basic fuel injection amount is corrected to increase the warm-up amount to increase the line-to-line output during warm-up operation. In order to improve drivability, the basic fuel injection amount is increased or decreased depending on various driving conditions.

[Problems to be Solved by the Invention] However, as described above, when correcting the basic fuel injection amount and calculating the actual fuel injection amount actually supplied to the internal combustion engine, the correction for increasing or decreasing the amount of fuel is necessary. The coefficients are determined in accordance with each operating state, and are determined by multiplying the basic fuel injection amount J by each correction coefficient, so if high-load operation is performed during warm-up, the The basic fuel injection amount is multiplied by the warm-up increase correction coefficient that is set and the output increase correction coefficient that is set based on the opening degree of the throttle valve, and the actual fuel injection amount becomes too large relative to the intake air amount. There are problems in that the air-fuel ratio becomes too rich, causing the spark plug to smolder and cause a misfire, or even if this does not occur, the output decreases and drivability deteriorates. That is, the above problem occurs because the output increase correction coefficient and the warm-up increase correction coefficient are independently determined in accordance with each operating condition. In the past, for example, Japanese Patent Application Laid-Open No. 57-135
As disclosed in Publication No. 234, although there is a method to limit the amount of warm-up twisting material injection, no measures have been taken to solve the above problem, and such measures are desired. Ta.

The present invention was developed in view of the above problem, and by setting the output increase correction coefficient according to the warm-up state of the internal combustion engine, the air-fuel ratio is prevented from becoming excessively rich even when performing high-load operation during warm-up. It is an object of the present invention to provide a fuel injection fill III device for an internal combustion engine that allows good drivability to be obtained without causing problems.

[Means for Solving the Problems] As shown in FIG. 1, the configuration of the present invention for achieving the above object includes an operating state detection means M for detecting the operating state of the internal combustion engine M1.
2, basic fuel injection maximum calculation means M3 that calculates the basic fuel injection amount according to the detected operating state, and detecting high load operation of the engine M1 from the detection result of the operating state H detection means M2. From the detection results of the high-load operation detection means M4 and the operation state detection means M2, the engine M
Warm-up state detection means M5 detects the warm-up state of the engine [! an internal combustion ill-related fuel injection ffi comprising: an actual fuel injection amount calculation means M6 that corrects the basic fuel injection amount to increase the warming up amount during warm-up operation of the IMI and calculates an actual fuel injection amount supplied to the engine; 1bIJ I
I! In the device, the output increase correction value used by the actual fuel injection amount calculation means M6 during high-load operation of the engine M1 is set to the engine M1.
output increase correction value setting means M that is set according to the warm-up state of the
Fuel injection ffi of an internal combustion engine characterized by providing 7
f, II crime device is the gist.

[Function] Here, the operating state detection means M2 refers to various sensors conventionally installed in electronically controlled internal combustion engines, such as a rotation speed sensor that detects the engine rotation speed, and a rotation speed sensor that detects the cooling water temperature. There are various sensors such as a water temperature sensor that detects the throttle valve opening, a throttle sensor that detects the opening of the throttle valve, an intake pipe pressure sensor that detects the intake pipe pressure, and an air-fuel ratio sensor that detects the air-fuel ratio based on the oxygen concentration in the exhaust gas. It will be done.

The basic fuel injection calculation means M3 calculates the fuel injection amount during steady engine operation based on the operating state of the internal combustion engine, such as intake pipe pressure or intake air amount, and is calculated from a microcomputer or the like. Naru electronic falJi1
This is executed as one of the processing operations of one circuit.

Next, high load operation detection means M4 and warm-up state detection means M5
This is to detect the high load operation of the internal combustion engine or the rM engine state from the detection result by the driving state detection means M2. It is determined that the engine is in high-load operation when the opening of the throttle valve exceeds a predetermined value or when the amount of depression of the accelerator pedal exceeds a predetermined value.
5, it may be determined that the engine is being warmed up when the engine temperature obtained from, for example, the cooling water temperature is below a predetermined value fIi.

In the actual fuel injection calculation means M6, the basic fuel injection amount determined by the peak means M3 for the basic fuel injection 1111 is corrected by increasing or decreasing according to the predetermined operating conditions of the engine,
This method calculates the actual amount of fuel injection actually supplied to the internal combustion engine, and at least when the internal combustion engine is operating under high load, the basic fuel injection amount is corrected to increase the engine output in order to increase the engine output, and when the engine is warmed up, the engine is cold or cold. This function corrects the basic fuel injection amount by increasing the warm-up amount in order to improve the drivability at the time of operation, and similarly to the basic fuel injection fJ4m calculation means M3, it is executed as one of the control processes in the electronic control circuit. .

Finally, the output increase correction value setting means M7 is a main part of the present invention, and determines the increase correction amount when the actual fuel injection amount calculation means M6 performs the output increase correction according to the warm-up state of the engine. , that is, set according to the temperature of the cooling water etc.
This is to prevent the air-fuel ratio from becoming too rich due to the □ increase correction when performing high-load operation during warm-up, resulting in a decrease in drivability.

[Example] An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 is a schematic configuration diagram showing an internal combustion engine and its peripheral equipment in which the internal combustion engine fuel injection all-system of this embodiment is mounted. In the figure, 1 is an internal combustion engine (hereinafter simply referred to as the engine), 2 is an intake pipe pressure sensor that detects the internal pressure of the intake manifold 3, and 4 is a sensor installed near each cylinder intake boat of the intake manifold 3 of the engine 1. The fuel injection valve 4 is an electromagnetically actuated fuel injection valve, and fuel whose pressure is adjusted to be constant is fed under pressure to the fuel injection valve 4. 5 is an ignition coil forming a part of the engine ignition system, and 6 is a distributor that distributes ignition and energy from the ignition coil 5 to spark plugs 5a provided in each cylinder. As is well known, the distributor 6 rotates once for every two revolutions of the crankshaft of the engine 1, and is provided with a rotation angle sensor 7 therein for detecting the engine rotation angle. 8
is an electronic control circuit consisting of a microcomputer,
This will be discussed later.

9 is the throttle valve of the engine 1, 10 is the throttle valve 9
A throttle sensor 11 having a full open contact 10a (not shown) that is turned ON when the throttle valve 9 is fully open or almost fully closed, and a full open contact 10b (not shown) that is turned ON when the throttle valve 9 is closed to an opening of 50' or more. 12 is a water temperature sensor that detects the cooling water temperature of the engine 1 to detect the warm-up state of the engine 1; 12 is an intake air temperature sensor that detects the intake air temperature;
An air-fuel ratio sensor 13 is provided in the exhaust manifold 14 and detects the air-fuel ratio from the oxygen concentration in the exhaust gas.

Next, FIG. 3 shows a block diagram of the electronic control circuit 8,
Its configuration will be explained.

As shown in the figure, the electronic control circuit 8 is a central processing unit that inputs and calculates the data output from each of the above-mentioned sensors according to a control program, and performs processing to control the operation of various devices such as the fuel injection valve 4 and the ignition coil 5. The unit (CPU) 20 stores data such as the control program and maps used when executing arithmetic processing, and the on-chip memory (ROM), where data necessary for executing arithmetic processing is temporarily read. A that converts analog signals from the intake pipe pressure sensor 2, cooling water temperature sensor 11, intake air temperature sensor 12, air-fuel ratio sensor 13, etc. into digital signals; An analog input boat 22 equipped with a /D converter and a multiplexer that selectively outputs each of these signals to the CPU 20, and similar to the analog input boat 22, a rotation angle sensor 7 and a throttle sensor 1.
a digital input port 23 that receives digital signals output from the fully closed contact 10a and fully open contact 10b, etc., and selectively outputs each signal to the CPU 20; a fuel injection valve 4 according to a control signal calculated by the CPU 20; Ignition coil 5
an output boat 24 that outputs drive signals to the CPU, etc.;
20, a storage unit 21, an analog input port 22, a digital input port 23, and a path line 25 connecting the output port 24 and through which each data is sent.

Then, this electronic control circuit 8 calculates the fuel injection amount, ignition timing, etc. according to the operating state of the engine 1 based on the detection signals from each of the above-mentioned sensors, and drives and controls the fuel injection valve 4 and the ignition coil 5. Next, the fuel injection amount calculation process, which is the main process according to the present invention, will be explained with reference to the flowchart shown in FIG. 4. still,
In this process, the fuel injection amount is calculated as the valve opening time of the fuel injection valve 4.

FIG. 4 shows a control program executed as one of the so-called main routines, which is a series of conventional control processes for controlling the fuel injection amount and ignition timing.

When the process starts, step 101 is first executed, detection signals from each of the above sensors are read, and then step 1 is executed.
Move to 02. In step 102, among the detection signals from the sensors read in step 101, the basic fuel injection is performed using a map or calculation formula (not shown) with the intake pipe pressure detected by the intake pipe pressure sensor 2 as a parameter. m is the basic valve opening time TP of the fuel injection valve 4
Calculated as

Next, in step 103, according to the cooling water temperature of the engine 1 detected by the water temperature sensor 11, the machine increase correction coefficient THW for the basic valve opening time TP obtained in step 102 is determined as shown in FIG. It is determined using a map or an arithmetic expression as shown, and the process moves to the following step 104.

Then, in step 104, the intake air temperature sensor 12
An intake air temperature correction coefficient THA is determined using a map or an arithmetic expression (not shown) according to the temperature of the air taken into the engine 1 detected in the step. Furthermore, this intake temperature correction coefficient THA
When the intake temperature is low, the air density is high, and when the intake temperature is high, the air density is low. Therefore, the fuel injection amount is increased or decreased depending on the temperature, and the air-fuel ratio is controlled at a constant level. It is a correction coefficient, similar to the warm-up increase correction coefficient THW, which is based on the basic fuel injection amount, that is, the basic valve opening time T.
This is used to correct P.

Next, in step 105, it is determined whether the fully closed contact 10a of the throttle sensor 10 is in the OFF state, that is, whether the engine 1 is in idle operation, and the fully open contact 10a is in the OFF state, and the engine 1 is in the idling state. If it is not inside, the process moves to the next step 106.

In step 106, the throttle sensor 1
It is determined whether or not all contact points 10b of 0 are in the ON state, that is, whether or not the engine 1 is operating under high load with the throttle valve 9 wide open. If it is in high load operation, the process moves to the following step 107.

Then, in step 107, the basic valve opening time TP is determined using a map or arithmetic expression as shown in FIG.
The output increase correction coefficient TVL is calculated for the output increase correction coefficient TVL, and the process moves to the next step 108.

On the other hand, the fully open contact 10b is turned OFF in step 106 above.
If it is determined that the engine 1 is not operating under high load, the process proceeds to step 109, where the output increase correction coefficient TVL is set to "1", and the process proceeds to the next step 108.

In step 108, a feedback correction coefficient TAF is calculated according to the air-fuel ratio of the air-fuel mixture supplied to the engine 1, which is detected by the air-fuel ratio sensor 13. Here, the feedback correction system aTA F is a system that reduces the fuel injection amount when the detected air-fuel ratio is on the rich side with respect to the target air-fuel ratio, and increases the fuel injection amount when it is on the lean side. This is a correction coefficient for correcting and controlling the air-fuel ratio to the target air-fuel ratio.

In this way, steps 103, 104,
Step 107 (or Step 109) and Step 1
Warm-up increase correction staff @THW in 08.

The intake temperature correction coefficient THA, the output increase correction coefficient TVL, and the feedback correction coefficient TAF are determined, and when the process moves to step 110, each of the determined correction coefficients and the step 102 are calculated.
The basic valve opening time TP, that is, the basic fuel injection amount, is corrected using the following formula % formula, which uses the basic valve opening time TP of the fuel injection valve 4 obtained as a parameter, and is equivalent to the actual fuel injection amount. When the fuel injection valve 4 is actually opened, 1iWTAU is numbed, and the processing of this routine is ended.

On the other hand, if it is determined in step 105 that the fully open contact 10a of the throttle sensor For example, if the engine speed NE determined based on the output signal is 1300
It is determined whether it is greater than or equal to [r,+)J,]. If NE≧1300, the process moves to the following step 112, sets the actual valve opening time TALI to rOJ, and finishes the processing of this routine.On the other hand, if NE<1300, the process moves to step 106. , executes a series of processes from step 106 to step 110 described above. Note that the processing in steps 105, 111, and 112 is performed when the engine rotational speed NE
When the number of rotations is higher than a predetermined number of revolutions, the fuel supply is temporarily stopped to prevent overheating of the catalyst and improve fuel efficiency.

As described above, in this embodiment, the output increase correction coefficient TVL for the fuel injection amount (valve opening time) used during high-load operation of the engine 1 is set in accordance with the cooling water temperature of the engine 1.

Therefore, when performing high-load operation during warm-up operation, such as when the engine 1 is cold, as is clear from the map in Fig. 6,
Since the output increase correction coefficient TVL is set to a smaller value as the cooling water temperature is lower, the increase correction does not make the air-fuel ratio too rich and reduce drivability, as in the conventional case.

In the above embodiment, in order to detect high-load operation of the engine 1, the opening degree of the throttle valve 4 is detected, and the time when the opening degree reaches a predetermined value (50') or more is defined as high-load operation. However, in addition to this, it is also possible to detect the accelerator opening and determine that high-load operation is occurring when the accelerator opening exceeds a predetermined value (or the intake air It can also be determined by the pipe pressure.However, if it is determined by the intake pipe pressure, the detection ability is poor because the responsiveness to changes in the accelerator opening and the throttle valve 4 is poor.

Further, in the above embodiment, the warm-up state of the engine 1 is detected based on the cooling water temperature, and the warm-up increase correction coefficient THW and the output! ja
The n correction coefficient TVL is set according to the cooling water temperature, but since it is sufficient to know the temperature of engine 1 to detect the engine status of engine 1, for example, the temperature of lubricating oil or the temperature at startup is It is also possible to detect the WJ111I state of the engine 1 from the cooling water temperature and the elapsed operating time after starting, and set the above correction coefficient. Therefore, for example, when setting the output increase correction coefficient based on the water temperature at startup and the elapsed operating time after startup, it is sufficient to use a map as shown in FIG. 7, for example. Further, in this case, the intake air temperature at the time of startup can be used instead of the cooling water temperature at the time of startup.

Furthermore, in the above embodiment, when the output increase is corrected during high load operation of the engine 1, the output increase correction coefficient THW is used as in the conventional case.
is used to multiply the basic fuel injection I (basic valve opening time), but in addition to this, the increase correction 11 (correction time) of the fuel injection m (valve opening time) corresponding to the increase correction coefficient THW is used. may be added to the basic fuel injection m (basic valve opening time).

[Effects of the Invention] As detailed above, in the fuel injection control device of the present invention, the output increase correction value for increasing the basic fuel injection amount during high-load operation of the internal combustion engine is Since the air-fuel ratio of the air-fuel mixture supplied to the internal combustion engine is configured to be set according to the engine condition, even if high-load operation such as sudden acceleration is performed during warm-up of the internal combustion engine, the air-fuel ratio of the mixture supplied to the internal combustion engine remains unchanged. It does not become too rich, and it is possible to prevent misfires and decreases in 1llffi output as in the conventional case, and it is possible to obtain good drivability. Furthermore, since the air-fuel mixture is well combusted, exhaust emissions can also be improved.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of the present invention, FIGS. 2 to 6 show an embodiment of the present invention, and FIG. 2 is a schematic configuration diagram showing the internal combustion engine and its peripheral equipment of the present embodiment. FIG. 3 is a block diagram showing the configuration of the electronic control circuit 8, FIG. 4 is a flowchart showing the fuel injection I [II output process executed by the electronic control circuit 20, and FIG. 5 is a warm-up addition correction section @
A diagram representing the map used when determining THW, Figure 6 is a miniature diagram representing the map used when determining the output increase correction coefficient TVL, and Figure 7 is a diagram representing the map used when determining the output increase correction coefficient TVL.
FIG. 12 is a diagram showing a map of another example for determining . Ml... Internal combustion engine M2... Operating state detection means M3... Basic fuel injection mis output means M4... High load operation detection means M5... Warm up state detection means M6... Actual fuel injection amount Calculation means M7...Output increase correction amount setting means 8...Electronic III m1 circuit 10...Throttle sensor 10b...All questions contact 11...Water temperature sensor

Claims (1)

[Scope of Claims] Operating state detection means for detecting the operating state of the internal combustion engine; basic fuel injection calculation means for calculating the basic fuel injection amount according to the detected operating state; A high-load operation detection means for detecting high-load operation of the engine based on the detection result; a warm-up state detection means for detecting the warm-up state of the engine from the detection result of the operating state detection means; During high-load operation, the basic fuel injection amount is corrected to increase the output in order to increase the engine output, and when the engine is warmed up, the basic fuel injection amount is corrected to increase the warm-up amount to increase the actual fuel supplied to the engine. In a fuel injection amount control device for an internal combustion engine, comprising an actual fuel injection amount calculation means for calculating an injection amount, an output increase correction value used by the actual fuel injection amount calculation means during high load operation of the engine, A fuel injection amount control device for an internal combustion engine, comprising an output increase correction value setting means that is set according to a warm-up state of the engine.