JPH09177580A - Fuel supply controller of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To highly accurately perform fuel supply control during warming up so as to improve exhaust performance, fuel efficiency and the like by correcting a temperature correction value for correcting a fuel supply amount according to an engine temperature to a fuel amount increase side according to an increase in an engine revolution speed. SOLUTION: In a control unit 10 to which signals are inputted from an air flow meter 11, a crank angle sensor 12, a throttle sensor 13, a water temperature sensor 14 and the like, a basic fuel injection amount is calculated, a target air-fuel ratio is calculated and thereby an effective fuel injection amount is calculated. When a key switch 16 is turned ON, determination is made as to whether a start time increase amount is 0 or not and if the determination is YES, an idling determination time is determined. At the time other than the idling determination time, the addition of a non-burnt increase amount is determined. On the other hand, during the idling determination time, determination is made as to whether a neutral switch 17 is ON or not and if NO, the addition of a non-burnt increase amount is determined. Then, in order to compensate for leaning of an actual in-cylinder air-fuel ratio, a non-burnt increase amount is added to the calculation of the target air-fuel ratio and the amount of fuel is increased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel supply control device for an internal combustion engine, and more particularly to improvement of a fuel supply control technique during warm-up.

[0002]

2. Description of the Related Art A conventional fuel supply control device of this type is disclosed in, for example, Japanese Patent Laid-Open No. 50-106033. JP-A-50-10603
In the one disclosed in Japanese Patent Publication No. 3, the temperature increase characteristic that depends on the engine water temperature during warm-up is continuously changed according to the engine rotation speed to correct the fuel supply amount, and stall, rough idle, etc. occur. Is to suppress.

[0003]

By the way, during a warm-up, for example, when there is a load fluctuation (for example, air conditioner operation / non-operation switching), a load fluctuation equivalent to that during normal time (after warm-up) is obtained. Even if the amount of fuel is increased or decreased,
The device disclosed in Japanese Patent Application Laid-Open No. 0-106033 has a fear that the stall, the rough idle and the like cannot be sufficiently suppressed.

There is also a system in which the fuel increase correction coefficient immediately after starting is adjusted according to the changing speed (rotational fluctuation) of the engine rotation speed to suppress the occurrence of stall, rough idle, and the like. (See Japanese Unexamined Patent Publication No. 5-141291, etc.), however, since the fuel correction is started after the rotation fluctuation due to the load fluctuation is detected, the followability is poor and the stall or rough idle immediately after the load fluctuation occurs. Can not be suppressed.

Then, the applicants of the present application have obtained the following new findings as a result of various analyzes based on the above points. That is, during warm-up (during cold), as shown in FIG. 13, even if the air-fuel mixture controlled to a constant air-fuel ratio (A / F) is supplied to the engine, the rotation speed and load increase. Accordingly, it was experimentally confirmed that the exhaust air-fuel ratio tends to be lean (lean).

[0006] This means that, during warm-up (when cold), as the rotational speed and load increase, the amount of fuel (unburned fuel) that is not actually used for combustion in the fuel supplied to the engine increases. , The in-cylinder air-fuel ratio becomes lean (for example, when the temperature is low, the vaporization / atomization characteristics of the fuel are poor, so it is likely that the fuel easily adheres to the cylinder wall and the amount that dissolves in the oil increases). It is thought to occur.

That is, during warm-up (when cold), it is necessary to further increase the amount of fuel supplied to the engine in accordance with an increase in rotation speed and load, as compared with after warm-up. However, in the past, regarding the fluctuation of the rotation speed even during the warm-up, it is assumed that the engine rotation is stabilized with the increase of the rotation speed, as shown in FIG. Was corrected to the weight loss side.
Therefore, it does not pose a problem in the conventional case where the air-fuel ratio is controlled to a relatively rich side during warm-up, but as in recent years, the air-fuel ratio is made lean during warm-up, and harmful exhaust gas components (particularly, HC, When attempting to reduce CO), if the fuel amount is corrected to the decreasing side as the rotation speed increases, stall or rough idle may occur as in the conventional case.

As described above, the stall, rough idle, etc., which are caused by the actual leaning of the in-cylinder air-fuel ratio, which is caused by the increase in load during warm-up, have not been considered in the past. The present invention has been made in view of the above circumstances, and during warming up, the fuel supply amount can be optimally corrected according to the engine temperature, the engine rotation speed, and the engine load, so that the operation during warming up is performed. It is an object of the present invention to provide a fuel supply control device for an internal combustion engine, which is capable of improving fuel efficiency, exhaust performance, fuel efficiency, and the like.

[0009]

For this reason, the fuel supply control apparatus for an internal combustion engine according to the invention described in claim 1 is as follows.
In order to correct the fuel supply amount setting means for setting the fuel supply amount according to the operating state, the engine temperature detecting means for detecting the engine temperature, and the set fuel supply amount according to the engine temperature as shown in FIG. Temperature correction value setting means for setting the temperature correction value, and temperature correction value rotation correction means for correcting the temperature correction value set by the temperature correction value setting means to the fuel increase side in accordance with the increase of the engine speed. , Based on the temperature correction value set by the temperature correction value setting means or the temperature correction value corrected by the temperature correction value rotation correction means,
Fuel supply amount correcting means for correcting the fuel supply amount set by the fuel supply amount setting means, and fuel supply amount set by the fuel supply amount setting means or fuel supply amount corrected by the fuel supply amount correcting means And a fuel supply control means for supplying the engine to the engine via the fuel supply device.

With such a configuration, a temperature fuel correction value (a fuel correction coefficient or a fuel correction amount, for example, a water temperature increase rate KTW which will be described later) corresponding to the engine temperature is increased as the engine speed is increased. Correct to the fuel increase side. Therefore, for example, during warm-up, as the engine speed increases, the amount of fuel not supplied for actual combustion (unburned fuel) in the fuel supplied to the engine increases, and the actual in-cylinder air-fuel ratio becomes lean. It is possible to control the fuel supply during warm-up with high accuracy, and to improve drivability, exhaust performance, fuel efficiency, etc. Will be possible.

A fuel supply control device for an internal combustion engine according to a second aspect of the present invention, as shown in FIG. 2, detects a fuel supply amount setting means for setting a fuel supply amount according to an operating state and an engine temperature. Engine temperature detecting means, a temperature correction value setting means for setting a temperature correction value for correcting the set fuel supply amount according to the engine temperature, and a temperature correction value set by the temperature correction value setting means. Is corrected to a fuel increase side in accordance with an increase in engine load, and a temperature correction value set by the temperature correction value setting means or a temperature correction value corrected by the temperature correction value load correction means. Fuel supply amount correcting means for correcting the fuel supply amount set by the fuel supply amount setting means based on the value, and the fuel supply amount set by the fuel supply amount setting means or the fuel supply The fuel supply amount corrected by the correction means, and fuel supply control means for supplying the engine via a fuel supply device, and configured to include.

With this configuration, the temperature fuel correction value according to the engine temperature is corrected to the fuel increase side as the engine load increases. Therefore, for example, during warm-up,
As the engine load increases, it is possible to prevent the amount of fuel not supplied for actual combustion (unburned fuel) of the fuel supplied to the engine from increasing and the actual in-cylinder air-fuel ratio from becoming lean. As a result, the fuel supply control during warm-up can be made highly accurate, which in turn can improve drivability, exhaust performance, fuel efficiency, and the like.

A fuel supply control device for an internal combustion engine according to a third aspect of the present invention, as shown in FIG. 3, detects a fuel supply amount setting means for setting a fuel supply amount according to an operating state and an engine temperature. Engine temperature detecting means, a temperature correction value setting means for setting a temperature correction value for correcting the set fuel supply amount according to the engine temperature, and a temperature correction value set by the temperature correction value setting means. Is a temperature correction value rotation / load correction means for correcting to the fuel increase side according to an increase in engine load and an increase in engine rotation, and a temperature correction value set by the temperature correction value setting means or the temperature correction value rotation.・
Based on the temperature correction value corrected by the load correction means,
Fuel supply amount correcting means for correcting the fuel supply amount set by the fuel supply amount setting means, and fuel supply amount set by the fuel supply amount setting means or fuel supply amount corrected by the fuel supply amount correcting means And a fuel supply control means for supplying the engine to the engine via the fuel supply device.

With such a configuration, the temperature fuel correction value corresponding to the engine temperature is corrected to the fuel increase side as the engine speed increases and the engine load increases. Therefore, for example, during warm-up, as the engine speed and engine load increase, the amount of fuel not supplied for actual combustion (unburned fuel) in the fuel supplied to the engine increases and the actual in-cylinder air-fuel ratio increases. It is possible to control the fuel supply control during warming up with high accuracy, and thus to improve drivability, exhaust performance, fuel efficiency performance, etc. It can be improved.

According to the fourth aspect of the present invention, when the fuel amount increase correction is performed at the time of starting the engine or after starting the engine,
The temperature correction value setting means is configured to include a prohibiting means for prohibiting correction of the temperature correction value set by the temperature correction value setting means. That is, since a relatively rich air-fuel mixture is supplied to improve ignitability and combustion stability at the time of engine startup or after engine startup, the engine rotation speed and load increase during warm-up according to the present invention ( (To compensate for the increase in unburned fuel)
Since the demand for increasing correction is small, in such a case, the prohibiting means prohibits the increasing correction according to the present invention. As a result, it becomes possible to reliably suppress deterioration of fuel efficiency, exhaust performance, and drivability due to overrich.

According to the fifth aspect of the invention, when the air-fuel ratio of the engine intake air-fuel mixture is set leaner than the stoichiometric air-fuel ratio, the temperature correction value set by the temperature correction value setting means is corrected. Configured to allow that. As a result, when the air-fuel ratio is controlled to a relatively rich side during warm-up, it is prevented from being further corrected to the rich side. It is possible to reliably suppress the deterioration of the sex.

[0017]

According to the first aspect of the present invention, the temperature fuel correction value according to the engine temperature is corrected to the fuel increase side as the engine speed increases, so during warming up. ,
Suppressing the fact that as the engine speed increases, the amount of fuel not supplied to actual combustion (unburned fuel) in the fuel supplied to the engine increases and the actual cylinder air-fuel ratio becomes lean. As a result, the fuel supply control during warm-up can be made highly accurate, which in turn can improve drivability, exhaust performance, fuel efficiency, and the like.

According to the second aspect of the present invention, the temperature fuel correction value according to the engine temperature is corrected to the fuel increase side as the engine load increases. Therefore, during warm-up, the engine load is increased. It is possible to suppress that the fuel amount (unburned fuel) that is not used for actual combustion increases and the actual in-cylinder air-fuel ratio becomes lean as the fuel supply to the engine increases. As a result, the fuel supply control during warm-up can be made highly accurate, which in turn can improve drivability, exhaust performance, fuel efficiency, and the like.

According to the third aspect of the present invention, the temperature fuel correction value corresponding to the engine temperature is corrected to the fuel increase side as the engine speed increases and the engine load increases. During engine warm-up, as the engine speed and engine load increase, the amount of fuel (unburned fuel) that is not used for actual combustion increases, and the actual in-cylinder air-fuel ratio becomes lean. Since it is possible to suppress such things,
As a result, the fuel supply control during warm-up can be made highly accurate, which in turn can improve drivability, exhaust performance, fuel efficiency, and the like.

According to the fourth aspect of the present invention, it is possible to reliably suppress deterioration of fuel efficiency and exhaust performance, and deterioration of drivability due to overrich. According to the invention described in claim 5, for example, when the air-fuel ratio is controlled to a relatively rich side during warm-up, it is prevented from being further corrected to the rich side. It is possible to reliably suppress deterioration of drivability due to deterioration of performance and overrich.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the accompanying drawings. In FIG. 4 showing the overall configuration of the embodiment, the intake passage 4 of the engine 1 is
An air flow meter 11 that detects an intake air flow rate Q that is sucked in through the air cleaner 2 and a throttle valve 3 that controls the intake air flow rate Q in conjunction with an accelerator pedal are installed, and a manifold portion on the downstream side includes: An electromagnetic fuel injection valve 5 as a fuel supply device which is energized by a drive pulse signal transmitted from a control unit 10 which will be described later at a predetermined timing according to an operating state and the like to be opened and which injects fuel into each cylinder Is provided.

An ignition plug 6 is provided in each combustion chamber of the engine 1, and the ignition plug 6 is driven to fire at a predetermined ignition timing set by the control unit 10 in accordance with an operating state and the like. Thus, the air-fuel mixture drawn into the combustion chamber is ignited by spark ignition and combustion.
It should be noted that the engine exhaust is discharged through the exhaust manifold 7 to a catalytic converter 8 (for example, a three-way catalyst, an oxidation catalyst, a lean NO).
x may be a x-catalyst), but the purifying action of the catalytic converter 8 purifies harmful components in the exhaust gas.

The control unit 10 includes a CPU, R
It is composed of a microcomputer equipped with OM, RAM, input / output I / F, A / D converter, etc., and receives signals from various sensors. As various sensors, in addition to the air flow meter 11 described above, a crank angle sensor 12 and a throttle sensor 13 that detects the opening TVO of the throttle valve 3 (an "idle switch that generates an ON signal when the throttle valve 3 is fully closed") are used. IDLE S
W) may be incorporated). For example, in the case of a 4-cylinder engine, the crank angle sensor 12 uses the reference signal REF for each crank angle of 180 ° and the crank angle of 1 to 2 °.
The unit angle signal POS for each is output. The control unit 10 can detect the engine speed N by counting the crank unit angle signal POS input from the crank angle sensor 12 for a certain period of time or by measuring the cycle of the reference signal REF. It has become.

Further, a water temperature sensor 14 is provided as an engine temperature detecting means for detecting the engine water temperature (not limited to the water temperature, the engine temperature of other parts may be detected) TW facing the water jacket of the engine 1. Has been. Further, an air-fuel ratio sensor 15 is provided facing the exhaust manifold 7, and this air-fuel ratio sensor 15 detects the concentration of a specific component (for example, oxygen) in the exhaust gas, and the control unit 10 uses this to detect the air-fuel ratio (or It is possible to detect rich / lean for a predetermined air-fuel ratio.

Further, from the key switch 16, a starter ON signal as a signal for detecting the start of cranking (start of start) and the end of cranking (that is, completion of start).
A starter OFF signal is input to the control unit 10 as a signal for detecting the. Further, when an A / T transmission (not shown) is adopted, a neutral switch (NEUT SW) 17 for detecting whether or not the shift position is in the neutral position.
Is provided, and this signal is also input to the control unit 10.

An air conditioner switch (A / C SW) 18 for detecting the operation / non-operation of an air conditioner (not shown)
And signals from a power steering switch (PWST SW) 19 that detects the operation / non-operation of a power steering pump (not shown) and an electric load switch (LOAD SW) 20 that detects the operation / non-operation of other electric loads. Is also input to the control unit 10.

By the way, the control unit 10 receives signals from various sensors, and supplies fuel (injection) from the fuel injection valve 5 (driving pulse width) as follows.
Is set. That is, based on the intake air flow rate Q detected by the air flow meter 11 and the engine rotation speed N detected by the crank angle sensor 12, the basic fuel injection amount (pulse width) Tp (= K × Q / N,
N is the engine speed, K is a constant), the target fuel-air ratio (increase rate) TFBYA is calculated according to the operating state, and the effective fuel injection amount TIPS is calculated based on the Tp and the target fuel-air ratio TFBYA. Ask.

The target fuel-air ratio (increase rate) TFBY
In this embodiment, A is calculated by the following equation. TFBYA = Kas + KTW + KUB + K _MR + K _HOT + ... where Kas: start-up and post-starting increase rate KTW; water temperature increase rate (= KTW1 × KTW2) KUB; unburned amount increase rate (characteristic part of the present invention [additional part])
K _MR ; high load / high speed increase rate K _HOT ; increase rate at high water temperature, etc.

By the way, the water temperature increase rate KTW is determined by the water temperature increase amount KTW1 (see the table in FIG. 6) and the rotation correction amount K.
TW2 (see the table of FIG. 7)]. On the other hand, the unburned amount increase rate KU
B is for correcting the change in the unburned component (actual air-fuel ratio) due to the change in rotation and load (during warm-up) that is adopted for the first time in the present invention. The KUB
Details of the setting will be described later.

The effective fuel injection amount TIPS is
It is obtained by the following equation. TIPS = (Tp + KATHOS) × TFBYA × (α
+ KBLRC-1) + Ts where KATHOS; acceleration / deceleration wall flow correction amount according to throttle valve opening change α; air-fuel ratio feedback correction coefficient KBLRC; air-fuel ratio learning correction coefficient Ts; voltage correction amount (invalid injection pulse width) Is.

Next, regarding the warm-up fuel increase control routine executed by the control unit 10 in the present embodiment, specifically, the unburned fuel amount increase rate KUB is added to the calculation of the target fuel-air ratio (increase rate) TFBYA. The control for determining whether or not to perform the setting and the control for setting the unburned amount increase rate KUB when it is determined to add the unburned amount increase rate KUB will be described with reference to the flowchart of FIG. By the way, the fuel supply amount setting means, the temperature correction value setting means, the temperature correction value rotation correction means, the temperature correction value load correction means, the temperature correction value rotation / load correction means, the fuel supply amount correction means, and the fuel supply control according to the present invention. As shown in the flowchart of FIG. 5, the function as means is provided in the control unit 10 by software.

The routine is performed by the key switch 16
When the starter ON signal is input from (IGN K
Execution is started (by EY ON). That is, in step (denoted as S in the figure, the same applies hereinafter) 1, the starter (ST
SW) ON → OFF, that is, whether cranking (starting) is completed is determined. If YES, the process proceeds to step 2, and if NO, the process waits until YES. At this time, the fuel increase correction by Kas or KTW is performed as in the conventional case.

In step 2, it is determined whether or not the amount of increase at the time of starting, that is, the amount of increase Kas at the time of starting and after starting (the amount of increase correction that is gradually reduced from the elapsed time from the start of starting) becomes zero. If YES, the process proceeds to step 3 to determine whether or not the unburned fuel amount increase rate KUB needs to be added to the calculation of the target fuel-air ratio (increase rate) TFBYA. On the other hand, if NO, since a relatively rich air-fuel mixture is supplied to improve engine stability by Kas correction or the like, it is not necessary to add the unburned component increase rate KUB, and Kas is 0.
Wait until

The steps 1 and 2 correspond to the prohibition means according to the present invention. In step 3,
It is determined whether or not the idle determination is being performed. For example, the idle determination can be made based on the engine speed N, the throttle valve opening TVO (idle switch “IDLE SW”), and the like. If the answer is NO, it is determined that it is not during the idle determination, there is a high possibility that the rotation speed and the load will change, and the unburned amount increase rate KUB should be added, and the routine proceeds to step 4. On the other hand, if YES, it is determined that the idle determination is being performed, and the process proceeds to step 6 to determine whether to add the unburned amount increase rate KUB under other conditions.

In step 6, it is determined whether or not the neutral switch (NEUT SW) 17 is ON. If NO, it is determined that the engine 1 and the transmission (not shown) are connected, and there is a high possibility of occurrence of rotation fluctuation and load fluctuation, and it is determined that the unburned amount increase rate KUB should be added. Go to step 4. On the other hand, if YES, the process proceeds to step 7 in order to determine whether to add the unburned amount increase rate KUB under other conditions.

In step 7, the air conditioner switch (A /
C SW 18 and power steering switch (PWST S
W) 19 and electric load switch (LOAD SW) 20
It is determined whether or not a signal such as Any one
If two are input and a YES determination is made, it is determined that there is a rotation / load fluctuation, and it is determined that the unburned component increase rate KUB should be added, and the routine proceeds to step 4. On the other hand, if NO, it means that the engine is in a steady idle operation (during warm-up), and therefore, in order to maintain the fuel amount increase by the conventional water temperature increase rate KTW, step 3
Return to

Incidentally, the case where the process proceeds to step 4 is the case where the rotation / load fluctuation occurs, so that the unburned fuel content increases when the engine load or the engine rotation speed increases during warm-up, that is, the actual in-cylinder In order to supplement the lean air-fuel ratio, the unburned fuel amount increase rate KUB is calculated by the following equation in order to add the unburned fuel amount increase rate KUB to the calculation of the target fuel air ratio (increase rate) TFBYA.

KUB = KUBTW × KUBTP × KUBN KUBTW; basic water temperature increase rate (obtained by searching with reference to the solid line of the basic water temperature table TKUBTW in FIG. 8) KUBTP; load correction amount (table TKUBTP in FIG. 9)
KUBN; Rotation correction amount (obtained by search or the like by referring to the table TKUBN in FIG. 10) Note that the load correction amount KUBTP and the rotation correction amount KUBN are obtained.
9 and 10 are for compensating for an increase in the unburned fuel content when the engine load or the engine speed increases during warm-up, that is, for making the actual lean in-cylinder air-fuel ratio lean, and therefore are shown in FIG. As described above, the fuel amount is increased and corrected as the engine load Tp increases, and the fuel amount is increased and corrected as the engine rotational speed N increases as shown in FIG.

The basic water temperature correction factor KUBTW is shown in FIG.
As shown by the solid line in FIG.
The increase correction based on the unburned amount increase rate KUB is set so as not to overlap. And the unburned component increase rate KUB
Is added, the target fuel air-fuel ratio TFBYA (= Kas + KT
W + KUB + K _MR + K _HOT + ...) is calculated.

Next, in step 5, the final effective fuel injection amount (driving pulse width) TIPS is calculated according to the above-mentioned formula.
Is calculated. Then, a drive pulse corresponding to the effective fuel injection amount TIPS is sent to the fuel injection valve 5, and the fuel adjusted to a predetermined amount for each cylinder is injected and supplied to the engine 1. In addition, when Step 4 and Step 5 are not passed, the target fuel air-fuel ratio TFBYA (= Ka
s + KTW + K _MR + K based on _{HO T} + · · ·), the calculated effective fuel injection quantity TIPS is, the fuel injection valve 5 will be driven on the basis of this.

Here, FIG. 11 shows a functional block diagram showing the flow of FIG. 5 described above. In addition, an example of a time chart (when the idle switch is OFF) when the flowchart of FIG. 5 is executed is shown in FIG.
Will be shown. As described above, according to the present embodiment, the fuel increase characteristic (during warm-up) is set according to the engine water temperature based on the engine water temperature TW, the rotation speed N, and the engine load Tp. When there is an increase in rotation, an increase in load, etc. in the machine, the amount of fuel not supplied for actual combustion (unburned fuel) in the fuel supplied to the engine 1 increases, and the actual in-cylinder air-fuel ratio becomes lean. It is possible to control the fuel supply during warm-up with high accuracy, and thus improve drivability, exhaust performance, fuel efficiency, etc. be able to.

In this embodiment, the engine speed N
It is described that the correction amount according to the engine water temperature is set based on both the engine load Tp and the engine load Tp. However, in some cases, one of the engine rotation speed N and the engine load Tp is set. The fuel increase characteristic during warming up may be set (in the direction of increasing the increase rate as the rotation speed or the load increases).

Further, in the present embodiment, the KTW similar to the conventional one is used.
Has been described as being always added to the target fuel air-fuel ratio TFBYA. However, for example, the basic water temperature table TKUBTW
The target fuel air-fuel ratio TFBYA is set according to the engine temperature, the engine load, and the engine rotation speed only with the unburned fuel content increase rate KUB by changing the contents (settings and characteristics) of FIG. To be able to do so, that is, the target fuel air-fuel ratio TFB
YA (= Kas + KUB + K _MR + K _HOT + ..., That is, KTW is abolished). In addition,
In this case, it is not necessary to determine whether or not the unburned amount increase rate KUB as described in the flowchart of FIG. 5 should be added to the target fuel air-fuel ratio TFBYA, so that the configuration can be simplified. It will be possible. However, according to the present embodiment, the existing control unit 10 and the like can be used without being significantly modified, which leads to cost reduction and the like.

In the present embodiment, the case where the A / T transmission device is provided has been described, but when the M / T transmission device is provided, step 6 of the flowchart of FIG. 5 may be omitted. Is. By the way, when the air-fuel ratio of the engine intake air-fuel mixture is set to be leaner than the stoichiometric air-fuel ratio, correction is performed by the unburned component increase rate KUB in the present embodiment, and the air-fuel ratio of the engine intake air-fuel mixture is changed to the theoretical air-fuel ratio. When the fuel ratio is set to the rich side, the normal KTW correction may be performed as in the conventional case. As a result, when the air-fuel ratio is controlled to a relatively rich side during warm-up, it can be suppressed that the fuel amount is further corrected to the rich side. On the other hand, if the air-fuel ratio of the engine intake air-fuel mixture is set leaner than the stoichiometric air-fuel ratio, it is possible to increase the rotation speed, increase the load, etc. during warm-up. Since it is possible to prevent the amount of fuel (unburned fuel) that is not actually used for combustion in the fuel supplied to the engine 1 from increasing and the actual in-cylinder air-fuel ratio from becoming lean, Therefore, the fuel supply control during warm-up can be made highly accurate, and in turn, drivability, exhaust performance, fuel efficiency performance, etc. can be improved.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration according to a first aspect of the invention.

FIG. 2 is a block diagram showing a configuration according to a second aspect of the invention.

FIG. 3 is a block diagram showing a configuration according to a third aspect of the invention.

FIG. 4 is a diagram showing an overall configuration according to an embodiment of the present invention.

FIG. 5 is a flowchart of a warm-up fuel increase control routine according to the embodiment.

FIG. 6 is a diagram showing an example of a search table of KTW1 according to the embodiment.

FIG. 7 is a diagram showing an example of a search table of KTW2 according to the embodiment.

FIG. 8: Basic water temperature increase rate KUB according to the embodiment
The figure which shows an example of the search table of TB.

FIG. 9 is a load correction amount KUBTP according to the embodiment.
Showing an example of the search table of FIG.

FIG. 10 is a rotation correction amount KUBN according to the embodiment.
Showing an example of the search table of FIG.

FIG. 11 is a functional block diagram of the flow of FIG.

FIG. 12 is a time chart when the flow of FIG. 5 is executed.

FIG. 13 is a diagram for explaining the influence of the engine speed and engine load during warm-up on the exhaust air-fuel ratio (actual in-cylinder air-fuel ratio).

[Explanation of symbols]

 1 Engine 5 Fuel Injection Valve 10 Control Unit 11 Air Flow Meter 12 Crank Angle Sensor 13 Throttle Sensor 14 Water Temperature Sensor 15 Air-Fuel Ratio Sensor 16 Key Switch 17 Neutral Switch 18 Air Conditioner Switch 19 Power Steering Switch 20 Electric Load Switch

Claims (5)

[Claims] 1. A fuel supply amount setting means for setting a fuel supply amount according to an operating condition, an engine temperature detecting means for detecting an engine temperature, and a correction means for correcting the set fuel supply amount according to the engine temperature. Temperature correction value setting means for setting the temperature correction value, and temperature correction value rotation correction means for correcting the temperature correction value set by the temperature correction value setting means to the fuel increase side in accordance with the increase of the engine speed. A fuel for correcting the fuel supply amount set by the fuel supply amount setting means based on the temperature correction value set by the temperature correction value setting means or the temperature correction value corrected by the temperature correction value rotation correction means The supply amount correction means and the fuel supply amount set by the fuel supply amount setting means or the fuel supply amount corrected by the fuel supply amount correction means are supplied to the engine through the fuel supply device. Fuel supply control apparatus for an internal combustion engine to a fuel supply control means for, characterized in that it is configured to include. 2. A fuel supply amount setting means for setting a fuel supply amount according to an operating condition, an engine temperature detecting means for detecting an engine temperature, and a correction means for correcting the set fuel supply amount according to the engine temperature. Temperature correction value setting means for setting the temperature correction value, and temperature correction value load correction means for correcting the temperature correction value set by the temperature correction value setting means to the fuel increase side in accordance with an increase in engine load, Fuel supply for correcting the fuel supply amount set by the fuel supply amount setting means based on the temperature correction value set by the temperature correction value setting means or the temperature correction value corrected by the temperature correction value load correction means A fuel supply amount set by the fuel supply amount setting device or a fuel supply amount corrected by the fuel supply amount correction device is supplied to the engine through a fuel supply device. Fuel supply control apparatus for an internal combustion engine, characterized in that configured to include a fuel supply control means. 3. A fuel supply amount setting means for setting a fuel supply amount according to an operating state, an engine temperature detecting means for detecting an engine temperature, and a correction means for correcting the set fuel supply amount according to the engine temperature. Temperature correction value setting means for setting the temperature correction value of the temperature correction value, and temperature correction value for correcting the temperature correction value set by the temperature correction value setting means to the fuel increase side in accordance with the increase of the engine load and the increase of the engine speed. Set by the fuel supply amount setting means based on the value rotation / load correction means and the temperature correction value set by the temperature correction value setting means or the temperature correction value corrected by the temperature correction value rotation / load correction means. The fuel supply amount correcting means for correcting the fuel supply amount, and the fuel supply amount set by the fuel supply amount setting means or the fuel supply amount corrected by the fuel supply amount correcting means. Fuel supply control apparatus for an internal combustion engine, characterized in that configured to include a fuel supply control means for supplying the engine via a supply device. 4. When the engine is started or after the fuel amount increase correction is started, a prohibiting means for prohibiting the correction of the temperature correction value set by the temperature correction value setting means is included. The fuel supply control device for an internal combustion engine according to any one of claims 1 to 3, characterized in that. 5. When the air-fuel ratio of the engine intake air-fuel mixture is set leaner than the stoichiometric air-fuel ratio, correction of the temperature correction value set by the temperature correction value setting means is permitted. The fuel supply control device for an internal combustion engine according to any one of claims 1 to 4.