JPS62203942A - Controller for internal combustion engine - Google Patents

Abstract

PURPOSE:To prevent the drop of fuel consumption and stabilize the output of an engine, by varying fuel injection timing or a prescribed air-fuel ratio set for a leaner side than a theory air-fuel ratio with a varying means corresponding to humidity detected by a humidity detecting means. CONSTITUTION:A control means M3 which determines and outputs fuel injection timing and fuel making an air-fuel ratio for a leaner prescribed air-fuel ratio than a theory air-fuel ratio corresponding to the operation condition of an internal combustion engine M1 detected by an operation condition detecting means M2 is provided. And in such a controller, a humidity detecting M4 which detects the humidity of intake air is provided, and at least one of the fuel injection timing and the prescribed air-fuel ratio is varied by a varying means M5 corresponding to the detected humidity. For example, the fuel injection timing is retarded in accordance with the increase of humidity, and the fuel injection timing is advanced in accordance with the decrease of humidity. Or, the prescribed air-fuel ratio is varied for a richer side in accordance with the increase of humidity, and the prescribed air-fuel ratio is varied for a leaner side in accordance with the decrease of humidity.

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention [Field of Industrial Application] The present invention relates to a control device for an internal combustion engine that is effective when the humidity of intake air of an internal combustion engine that performs lean combustion changes.

[Prior Art] Conventionally, methods for controlling ignition timing have been known in order to prevent abnormal combustion in internal combustion engines caused by changes in the humidity of outside air. For example, (1) an "ignition timing control device" that advances the ignition timing in accordance with an increase in outside air humidity detected by a humidity detection means (Japanese Patent Publication No. 59-41021); (2) detects the humidity of intake air; A ``method for controlling ignition timing of an internal combustion engine'' (Japanese Unexamined Patent Publication No. 105555/1983) has been proposed in which ignition timing is controlled in accordance with the detected intake air humidity.

These are designed to correct fluctuations in the knock margin advance angle that occur due to a decrease in combustion temperature due to changes in humidity, and to prevent the occurrence of knocking even if the knock margin advance angle is reduced.

Incidentally, in recent years, for the purpose of improving fuel efficiency and exhaust characteristics, internal combustion engines have been developed that perform so-called lean combustion control in which combustion is performed in an internal combustion engine at a lean air-fuel ratio that is thinner than the stoichiometric air-fuel ratio.

[Problems to be Solved by the Invention] The following problems arose in this prior art. In other words, (1) In general, there is a relationship between humidity, fuel efficiency, torque fluctuation, and NOx emissions as shown in Figure 14.As shown in the figure, as humidity increases, fuel efficiency and torque fluctuation increase; When the humidity is high, the amount of NOx emitted is large. This tendency is particularly noticeable during the lean combustion control described above.

By the way, in lean burn control, the setting of fuel injection timing and lean air-fuel ratio are closely related to its effectiveness.

Therefore, both of the above set values have been set to constant values based on the low humidity conditions so as not to deteriorate the exhaust characteristics even in low humidity conditions when the amount of NOx emissions is large, as described above. Therefore, a problem arises in that the set values of the fuel injection timing and lean air-fuel ratio are not corrected in accordance with changes in humidity.

(2) For example, as shown in Figure 15, for the purpose of reducing NOx emissions during low humidity, the fuel injection timing is set to a constant value around 20 [°C] after intake top dead center (TDC). Then, as shown by the broken line in the same figure, there was a problem in that fuel consumption and torque fluctuations increased due to the increase in humidity, and driving performance deteriorated.

(3) For example, as shown in Figure 16, if the air-fuel ratio is set to a value around 22 for the purpose of reducing NOx emissions at low humidity, the same result will occur as in case (2) above. As shown by the broken line in the figure, there was also the problem that fuel consumption and torque fluctuations increased as humidity increased.

An object of the present invention is to provide a control device for an internal combustion engine that performs lean combustion control by correcting at least one of the fuel injection timing and the air-fuel ratio set value when the humidity of intake air changes.

Structure of the Invention [Means for Solving the Problems] The present invention, which has been made to solve the above problems, as illustrated in FIG.
2, and a control means M3 for determining and outputting a fuel injection timing and an amount of fuel to make the air-fuel ratio of the internal combustion engine a predetermined air-fuel ratio leaner than the stoichiometric air-fuel ratio, according to the detected operating state. The internal combustion engine control device further includes a humidity detection means M4 for detecting the humidity of intake air of the internal combustion engine M1, and a change for changing at least one of the fuel injection timing or the predetermined air-fuel ratio in accordance with the detected humidity. The gist of the present invention is a control device for an internal combustion engine, comprising: means M5;

The operating state detection means M2 is for detecting the operating state of the internal combustion engine M1. For example, it can be realized by various sensors that detect the amount or pressure of intake air, the rotational state of Ml of the internal combustion engine, the cooling water temperature, the intake air temperature, the residual oxygen concentration in the exhaust gas, and the like.

The control means M3 determines and outputs fuel injection timing and fuel cylinders that achieve combustion at a predetermined air-fuel ratio leaner than the stoichiometric air-fuel ratio, depending on the operating state. For example, the above-mentioned fuel injection timing and basic fuel amount are determined based on the amount or pressure of intake air and the rotational speed, and the above-mentioned basic fuel amount is further corrected according to intake air temperature, cooling water temperature, oxygen concentration, etc. It can be configured to define a tube.

The humidity detection means M4 is for detecting the humidity of intake air. For example, the humidity in the intake pipe of the internal combustion engine M1 may be detected, or the humidity of the intake air may be detected by measuring the outside air humidity of the internal combustion engine M1. The detector can be realized by, for example, a thermistor humidity sensor with good response, a ceramic humidity sensor with high durability and reliability, or a ceramic humidity sensing element that outputs an analog signal depending on humidity.

The changing means M5 changes at least one of the fuel injection timing and the predetermined air-fuel ratio depending on the humidity. For example, this can be achieved by delaying the fuel injection timing in response to an increase in humidity, and advancing the fuel injection timing in response to a decrease in humidity.

Further, for example, the predetermined air-fuel ratio may be changed to a richer side in response to an increase in humidity, and the predetermined air-fuel ratio may be changed to a leaner side in response to a fall in humidity. For example, both the fuel injection timing and the predetermined air-fuel ratio may be changed depending on the humidity as described above.

The control means M3 and the change means M5 can be realized, for example, by independent disk sort logic circuits. Alternatively, for example, it may be configured as a logic operation circuit together with a well-known CPU, ROM, RAM, and other peripheral circuit elements, and may realize both of the above means according to a predetermined processing procedure.

[Operation] As illustrated in FIG. 1, the internal combustion engine control device of the present invention determines the fuel injection timing and the stoichiometric air-fuel ratio according to the operating state of the internal combustion engine M1 detected by the operating state detecting means M2. When the control means M3 determines and outputs the amount of fuel that achieves a lean predetermined air-fuel ratio, the changing means M5 changes at least one of the fuel injection timing or the predetermined air-fuel ratio according to the humidity detected by the humidity detection means M4. It works like that.

That is, during lean combustion control, at least one of the fuel injection timing and the predetermined air-fuel ratio is changed in accordance with changes in the humidity of intake air.

Therefore, the internal combustion engine control device of the present invention operates to suitably control the combustion state of the internal combustion engine M1 even if the humidity of the intake air changes during lean combustion control. The technical problems of the present invention are solved by each component of the present invention acting as described above.

[Example] Next, a preferred example of the present invention will be described in detail based on the drawings. A system configuration of an embodiment of the present invention is not shown in FIG.

The engine 1 has four cylinders that are formed of a cylinder 2, a piston 3, and a cylinder head 4 and each cylinder is provided with a combustion chamber 6 having an ignition plug 5.

The intake system of the engine 1 is composed of an intake pipe 7 that communicates with the combustion chamber 6, a surge tank 8 that absorbs pulsation of intake air, a throttle valve 9 that adjusts the amount of intake air, and an air cleaner 10 that purifies the intake air. There is.

On the other hand, the exhaust system of the engine 1 includes an exhaust pipe 11 that communicates with the combustion chamber 6, and a three-way catalyst 1 that purifies harmful components in the exhaust gas.
2.

The fuel system of the engine 1 includes a fuel tank and a fuel pump (not shown), and supplies fuel to a fuel injection valve 13 disposed for each cylinder near the intake port of each cylinder. The fuel injection valve 13 injects fuel corresponding to the intake stroke of each cylinder.

The ignition system of the engine 1 includes an igniter 14 that outputs the high voltage necessary for ignition, and a distributor 15 that distributes the high voltage generated by the igniter 14 to the spark plugs 5 of each cylinder in conjunction with a crankshaft (not shown). configured.

The engine 1 is installed in the intake pipe 7 as a detector.

an intake pipe pressure sensor 21 for detecting intake air pressure;
An intake air temperature sensor 22 is disposed inside the air cleaner 10 to detect the intake air temperature, a humidity sensor 23 is disposed in the intake pipe 7 to measure the humidity of the intake air, and the humidity is detected in conjunction with the throttle valve 9. A throttle position sensor 24, a water temperature sensor 25 installed in the cooling water system of the cylinder block to detect the cooling water temperature, and an oxygen concentration installed in the exhaust pipe 11 to detect the residual oxygen concentration in the exhaust and output it as an analog signal. A sensor 26 and an exhaust temperature sensor 27 for detecting exhaust temperature are provided.

Further, inside the distributor 15, there is a rotation angle sensor 28 which also serves as a rotation speed sensor that outputs a rotation angle signal every 1/24 revolution of the camshaft, that is, every integer multiple of the crank angle ○° to 30°. A cylinder discrimination sensor 29 is provided that outputs a reference signal once for each rotation of the camshaft of the distributor 15, that is, for every two rotations of the crankshaft (not shown).

The detection signals of each of the above sensors are transmitted by the electronic control unit (hereinafter simply EC).
U! ;o) is input to 30, and the ECU 3O controls the engine 1.

Next, the configuration of the ECU 3O will be explained based on FIG. 3. ECU3O is CPU30a, ROM30b, RAM
30c and a backup RAM 30d as a central logic operation circuit, and are connected to input/output ports 1 to 30f and 3 (E and output port 30h) via a common bus 30e to perform input/output with the outside.

The ECtJ30 has buffers 30i, 30J, 30 for the output signals of the sensors 30m, 30n, 3
0p, a multiplexer 30q that selectively outputs the output signal of each sensor to the CPU 30a, and an A/D converter 30r that converts an analog signal into a digital signal, and these signals are input to the CPU 30a via an input/output port 30f. Ru.

In addition, the ECU 3O is a buffer '30S for the output signal of the exhaust temperature sensor 27, a cylinder discrimination sensor 29, and a rotation angle sensor 2.
A waveform shaping circuit 301 is provided to shape the waveform of the output signal from the input/output port 30C.
It is input to PU30a.

In general, the ECU 3O controls each fuel injection QJ valve 13a, 13b, 13c, 13d of the first to fourth cylinders and the igniter 14.
Drive circuit 30u, 30V, 30W that applies drive current to
, 30X, and 30y, and the CPU 30a is the output port 3.
The respective drive circuits 30u, 30v, 30w,
Control signals are output to 30x and 30y. Also, ECU3
O has a timer 302 for timing, and output port 30
A conveyor register that outputs an interrupt signal to the CPU 30a when a preset time coincides with the word time of the timer 302 is also disposed within h.

Next, the processing executed by the ECU 3Q is shown in FIG.
This will be explained based on the flowcharts shown in FIGS. 6, 9, and 10. Fig. 4 shows the ignition timing calculation process, Fig. 6 shows the fuel injection control amount calculation process, Fig. 9 shows the fuel injection start process, and Fig. 10 shows the fuel injection end process, which will be explained in this order below. .

First, the ignition timing calculation process will be explained based on flowchart 1 to FIG. 4. In step 100, the intake pipe internal pressure P
A process is performed to calculate the basic ignition timing θBSE according to a map based on M and the rotational speed Ne. In the following step 110, the humidity sensor 23 detects the humidity PW of the intake air. Next, the process proceeds to step 120, where a process of calculating an ignition timing correction value θPW based on the humidity PW is performed. Here, there is a relationship as shown in FIG. 5 between the humidity PW and the ignition timing correction value θPW.

That is, the ignition timing is corrected to the advanced side as the humidity increases. The ECU3O has prepared the RO map as shown in Fig. 5 in advance.
It is stored in M30b, and the humidity PW is determined according to the map.
The ignition timing correction value θPW is calculated from Next step 1
At step 30, it is determined whether or not the intake pipe internal pressure PM is 700 [mmHQ] or more. If the determination is affirmative, the process proceeds to step 140 as a high load state, and the ignition timing correction value θPW is set to prevent knocking. After setting the value O to the value O, the process proceeds to step 150. On the other hand, if it is determined in step 130 that the intake pipe internal pressure PM is less than 700 [mrTIHC], the process proceeds to step 150. In step 150, the ignition timing θ is calculated by adding and correcting the ignition timing correction value θPW to the basic ignition timing θBSE, and then it can be handled to rNEXTJ. Thereafter, this ignition timing calculation process is repeatedly executed in accordance with the ignition of each cylinder. In addition, the intake pipe internal pressure PM, rotational speed Ne, and humidity PW
Based on the three-dimensional map that defines the ignition timing θ,
The ignition timing θ may be calculated directly. When calculating in this way, the ejection accuracy is improved.

Next, the fuel injection control amount calculation process will be explained based on the flowchart of FIG. This fuel injection control amount calculation process is as follows:
This process is repeated every 60 ['CA] before the intake top dead center of each cylinder. In step 200, a process is performed to calculate the basic fuel injection time TP according to a map based on the intake pipe internal pressure PM and the rotational speed Ne. Next step 21
0, a process is performed to calculate the lean air-fuel ratio correction coefficient KLEAN according to a map based on the intake pipe internal pressure PM, rotational speed Ne, and cooling water temperature THW. For example, if the lean air-fuel ratio correction coefficient KLEAN is found to be 0.8, the stoichiometric air-fuel ratio value 14.8 is converted to the 8 lean air-fuel ratio correction coefficient KLEAN.
The value 18.5 divided by LEAN becomes the basic target air-fuel ratio.

Next, the process proceeds to step 220, where a process of detecting the humidity PW of the intake air from the humidity sensor 23 is performed. In the following step 230, a process of calculating an air-fuel ratio correction value K from the humidity PW is performed. Here, there is a relationship between the humidity PW and the air-fuel ratio correction value as shown in FIG.

In other words, the air-fuel ratio correction value increases as the humidity increases.

The ECU3O has a map shown in Fig. 7 stored in the ROM in advance.
30b, and calculates the air-fuel ratio correction value K from the humidity PW according to the map.

Here, for example, if the air-fuel ratio correction value K is found to be 1.1,
The value 16.8 obtained by dividing the above-mentioned basic target air-fuel ratio value 18.5 by the above-mentioned air-fuel ratio correction value becomes the target air-fuel ratio. Next, proceed to step 240, and calculate the actual fuel injection time TAU using the following formula (1).
The calculation process is performed as follows.

TAU=TPxKLEANxKXC...(1) However,
The correction coefficient C is based on the cooling water temperature THW and the intake air temperature THA.
, the air-fuel ratio feedback correction coefficient FAF, etc.

In the subsequent step 250, the basic fuel injection timing is determined as a crank angle according to the map from the intake pipe internal pressure PM and the rotational speed Ne, and the basic fuel injection timing TINJ is calculated by roughly converting the crank angle into time. . Next, the process proceeds to step 260, where a process of calculating a fuel injection timing correction value Δt from the humidity PM is performed. Here, there is a relationship as shown in FIG. 8 between the humidity PM and the crank angle display value ΔA of the fuel injection timing correction value. That is,
As the humidity increases, the fuel injection timing is corrected to the retarded side. E
CU3O stores a map as shown in Fig. 8 in advance in ROM30.
According to the above map according to the humidity PW, first calculate the crank angle display value ΔA of the fuel injection timing correction value, and roughly convert this value into the fuel injection timing correction value ΔT. Convert. In the following step 270, a process is performed to calculate the fuel injection start time INJON according to the following equation (2>).

I NJON=TIMER 10 TI NJ+Δ1...(
2) However, the value TIMER is the current time measured by the timer 3oz.

Next, the process proceeds to step 280, where the fuel injection start time INJO is determined.
After setting N in the conveyor register of output port 30h, it can be handled to rNEXTJ. Thereafter, this fuel injection control amount calculation process is repeatedly executed every time the above-described execution condition is satisfied.

Next, the fuel injection start process will be explained based on the flowchart of FIG. As described above, this fuel injection start process is interrupted and executed when the fuel injection start time set in the conveyor register and the timed value of the timer 30z match. In step 300, a process is performed to open the fuel injection valve 13 corresponding to the cylinder that has reached the intake stroke. In the following step 310, the fuel injection end time INJOFF is determined.
A process is performed to calculate as shown in the following equation (3).

INJOFF=TIMER+TAU...(3)
However, the value TIMER is the current time measured by the timer 30z.

Next, the process proceeds to step 320, where the fuel injection end time INJO
After setting the FF to the conveyor register of the output port 30h, the - amount water fuel injection start process is completed. Thereafter, the present fuel injection start process is interrupted and executed when the above-mentioned starting condition is satisfied.

Next, the fuel injection termination process will be explained based on the flowchart of FIG. 10. This fuel injection termination process was set in the conveyor register as described above. The process is interrupted and executed when the fuel injection end time and the timed value of the timer 302 match. In step 400, after a process is performed to close the fuel injection valve 13 that was opened in the above-described fuel injection start process, the -amount water fuel injection end process is ended. From then on,
This fuel injection termination process is interrupted and executed every time the above-mentioned starting condition is satisfied.

Note that in this embodiment, the engine 1 is replaced by the internal combustion engine M1,
The intake pipe pressure sensor 21, the intake air temperature sensor 22, the water temperature sensor 25, the oxygen concentration sensor 26, the rotation angle sensor 28, and the cylinder discrimination sensor 29 correspond to the operating state detection means M2.

Further, the ECU 3O and the processes executed by the ECU 3O (steps 200.210, 250.280> function as the control means M3. Furthermore, the humidity sensor 23 corresponds to the humidity detection means M4, and the processes executed by the ECU 3O and the processes executed by the ECU 3O function as the control means M3. processing (steps 230, 240, 260,
270> functions as the changing means M5.

As explained above, in this embodiment, as the humidity of intake air increases, the ignition timing is advanced, and the basic target air-fuel ratio, which is set on the leaner side than the stoichiometric air-fuel ratio, is corrected to the richer side, thereby roughly increasing the fuel consumption. It is configured to delay the injection timing. Therefore, it is possible to prevent a decrease in fuel efficiency due to an increase in humidity, and to stabilize the amount of NOx emissions. That is, as shown in FIG. 11, when the humidity is PW1, the ignition timing is set according to the humidity PWI, so the fuel consumption is a value a1, and the NOx emission amount is a value C1. Eventually, due to a change in the outside air condition, the humidity increases from the humidity PW1 to the humidity PW2. In this case, if the ignition timing is set at the same 8 times, the fuel consumption changes as shown by the solid line in the figure, and the NOx emission amount changes as shown by the two-dot chain line.

Therefore, as the humidity increases, the fuel consumption increases from the value a1 to the value a2. However, in this embodiment, the ignition timing is advanced as the humidity increases. As a result, the fuel consumption changes as shown by the broken line in the figure, and the NOx emission amount changes as shown by the dashed line. Therefore, even if the humidity increases from humidity PW1 to humidity PW2, the fuel efficiency decreases from value a1 to value a3;
The NOx emission amount is maintained at the value C1. In addition, at high load (intake pipe pressure PM is 700 Cmmhg
1 or more), the ignition timing is not advanced, so knocking can be prevented.

Further, as shown in FIG. 12, when the humidity is low, the fuel consumption, torque fluctuation, and NOx emission amount change as shown by solid lines according to the air-fuel ratio. At such low humidity times, the air-fuel ratio is set to a value around 22 for the purpose of reducing NOx emissions. Therefore, the fuel consumption is the value a11, and the torque fluctuation is the value b11.
, the NOx emission amount becomes the value C11. On the other hand, when the humidity is high,
Fuel consumption, torque fluctuation, and NOx emissions change as shown by the broken line depending on the air-fuel ratio. Therefore, even in high humidity, if the air-fuel ratio is set around 22, the fuel consumption will be around the value a.
12, the torque fluctuation increases to the value b12.

However, in this embodiment, as the humidity increases, the air-fuel ratio is corrected from a value around 22 to, for example, a value around 20 on the rich side. Therefore, even if the humidity increases, the fuel consumption will be a value a13 and the torque fluctuation will be a value b13, which will be the same level or lower than when the humidity is low. Further, the NOx emission amount becomes a value C13, which can be maintained at the same value as when the humidity is low. Further, as shown in FIG. 13, when the humidity is low, the fuel consumption, torque fluctuation, and NOx emission amount change as shown by solid lines depending on the fuel injection timing. At times of such low humidity, the fuel injection timing is set to a value close to intake top dead center (TDC>(TDC>15 ['CA]) for the purpose of reducing NOx emissions.
The fuel consumption is a value a21, the torque fluctuation is a value b21, and the NOx emission amount is a value C21. On the other hand, when humidity is high, fuel efficiency, torque fluctuations, and NOx emissions change as shown by the broken line depending on the fuel injection timing. Therefore, even in high humidity conditions, if the fuel injection timing is set to a value close to 15 ["CA] after intake top dead center, the fuel consumption will reach the value a22, and the torque fluctuation will decrease to 1ia.
It increases to b22.

However, in this embodiment, as the humidity increases, the fuel injection timing is delayed, for example, to a value near 30 ['CA] after intake top dead center. Therefore, even if the humidity increases, the fuel consumption will remain at the value a23,
The torque fluctuation becomes a value b23, which is about the same value as when the humidity is low. Further, the NOx emission amount becomes a value of 023, which can be maintained at the same value as when the humidity is low.

Above) Due to the effects mentioned above, even if the humidity fluctuates, fuel efficiency does not decrease and driving performance is maintained in good condition.
Lean burn control can be performed without increasing the amount of X emissions.

In addition, in the fuel injection control amount calculation process of this embodiment, the air-fuel ratio correction value K is calculated regardless of the value of the lean air-fuel ratio correction coefficient KLEAN. However, for example, by the fuel injection control amount calculation process shown in FIG.
If the value of LEAN is 1.0 or more, the air-fuel ratio correction value K
may be constant (1, 0) (steps 522, 52
5>. Here, the value of the lean air-fuel ratio correction coefficient KLEAN is:
As shown in FIG. 18, it becomes 1.0 or more in a high load state. In such a combustion state with a relatively rich air-fuel ratio, both the NOx emission amount and the torque fluctuation are small, as described above. Therefore, the air-fuel ratio correction value K is set to 1.0.
By not increasing the fuel injection amount, the fuel consumption rate can be improved.

Furthermore, in the fuel injection control amount calculation process of this embodiment, the air-fuel ratio correction value K was calculated based on the humidity PW.

However, for example, if the air-fuel ratio correction value K is
, rotational speed Ne, and humidity PW, the accuracy is further improved.

Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments in any way, and it goes without saying that it can be implemented in various forms without departing from the gist of the present invention. .

Effects of the Invention As detailed above, the control device for an internal combustion engine of the present invention has a means for changing the fuel injection timing or a predetermined air-fuel ratio set to the leaner side than the stoichiometric air-fuel ratio in accordance with the humidity detected by the humidity detecting means. configured to change. Therefore, even if the humidity of the intake air changes during lean combustion control, it is possible to prevent a decrease in fuel efficiency and to stabilize the engine output, which is an excellent effect.

Furthermore, it is possible to suppress deterioration of exhaust characteristics due to changes in the humidity of intake air.

Furthermore, along with the above effects, the combustion state of the internal combustion engine that performs lean combustion can be optimally controlled depending on the outside air state.

[Brief explanation of drawings]

FIG. 1 is a basic configuration diagram conceptually illustrating the contents of the present invention, FIG. 2 is a system configuration diagram of an embodiment of the present invention, and FIG. 3 is a diagram for explaining the configuration of the electronic control device. 4 is a flowchart showing the control, FIG. 5 is a graph showing the map, FIG. 6 is a flowchart showing the control, and FIGS. 7 and 8 are graphs showing the map. , FIGS. 9 and 10 are flowcharts showing the same control, and FIGS. 11 to 13.
The figure is a graph similarly showing the effect, Figures 14 to 16 are graphs showing changes in various characteristic quantities corresponding to changes in humidity, Figure 17 is a flowchart showing other examples, and Figure 18 is a graph showing the effect.
The figure is also a graph showing the map. Ml... Internal combustion engine M2... Operating state detection means M3... Control means M4... Humidity detection means M5... Changing means 1... Engine 21... Intake pipe internal pressure sensor 23... Humidity sensor 28...Rotation angle sensor 30...Electronic control unit (ECU) 30 a ・CPU

Claims (1)

[Scope of Claims] 1. Operating state detection means for detecting the operating state of the internal combustion engine; and, in accordance with the detected operating state, adjusting the fuel injection timing and the air-fuel ratio of the internal combustion engine to a predetermined air-fuel ratio leaner than the stoichiometric air-fuel ratio. A control device for an internal combustion engine, comprising: a control device that determines and outputs a fuel amount as a fuel ratio; and a humidity detection device that detects humidity of intake air of the internal combustion engine; A control device for an internal combustion engine, comprising: changing means for changing at least one of the fuel injection timing or the predetermined air-fuel ratio. 2. The control device for an internal combustion engine according to claim 1, wherein the changing means delays the fuel injection timing in response to an increase in humidity, and advances the fuel injection timing in response to a decrease in humidity. 3. Claim 1, wherein the changing means changes the predetermined air-fuel ratio to a richer side in response to an increase in humidity, and changes the predetermined air-fuel ratio to a leaner side in response to a decrease in humidity. Control equipment for internal combustion engines.