JPH08121209A - Intake control device for engine - Google Patents

Abstract

PURPOSE: To prevent deterioration of operability and exhaust gas in a system where an intake control valve is varied in its opening based on a valve opening map set according to an engine operation condition by properly correcting a fuel injection rate irrespective of changeover speed, and suppressing fluctuation of an air-fuel ratio. CONSTITUTION: A tumble control valve 24 is arranged in an intake system of each cylinder of an engine main body 1, which valve is closed according to an engine operation condition for generating tumble flow, or opened for performing full open intake. An injector 26 is arranged on a downstream side of the tumble control valve 24 for injecting fuel to each cylinder. A valve opening is determined with reference to a map according to an engine operation condition. An opening/closing control means C1 controls the tumble control valve 24 based on the valve opening. A correction rate calculation means C2 calculates a primary delay correction rate at the time of opening/closing the valve with a value prepared by subracting a primary delay value from the valve opening of the tumble control valve 24. A fuel control means C3 corrects a fuel injection rate of the injector 26 based on the primary delay correction rate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intake control device for opening and closing an intake control valve (swirl control valve, tumble control valve) provided in an intake passage of a vehicle engine. For suppressing fluctuations in the air-fuel ratio in Japan.

[0002]

2. Description of the Related Art The following methods are known as measures for improving the combustion of a vehicle engine. That is, an intake control valve such as a swirl control valve or a tumble control valve is provided for each cylinder in the intake passage downstream of the throttle valve. In the low-to-medium load region of the engine operating condition, the intake control valve is closed to change the intake flow state to generate a swirl flow swirling in the cylinder in the circumferential direction or a tumble flow swirling in the cylinder in the axial direction. To do. This promotes the mixing of fuel and air to improve combustion and improve fuel efficiency. Further, in the high load region, the intake control valve is opened and the intake air is fully opened so that a large amount of air is taken in to improve the engine output.

Therefore, in this type of engine, when the engine operating state changes from the low to medium load region to the high load region, the intake control valve is controlled from closed to open, and conversely from the high load region to the low to medium load region. The intake control valve is controlled from open to closed when it changes to. By the way, if the intake control valve is opened / closed instantaneously, the intake air amount and the air-fuel ratio are suddenly increased / decreased to deteriorate the operability and the exhaust gas. Therefore, when opening and closing the intake control valve, it is necessary to consider so as to suppress fluctuations in the air-fuel ratio.

As a method of suppressing the variation of the air-fuel ratio when the intake control valve is opened / closed, an intermediate opening is set between full closing and full opening of the intake control valve to variably control the valve opening in three or more stages. Is proposed. According to this method, the opening degree of the intake control valve changes little by little and the fluctuation range can be reduced, but the number of times the intake air amount is measured by the air flow meter and the fuel injection amount is calculated increases. Also in this case, the opening of the intake control valve may be changed suddenly or slowly depending on the driving and running conditions. In particular, when the switching speed is high, the measurement of the intake air amount by the air flow meter may be delayed and the calculation of the fuel injection amount may not be in time, resulting in a change in the air-fuel ratio. Therefore, in the method of changing the opening degree of the intake control valve in small increments, it is required that the fuel injection amount be appropriately corrected in consideration of the delay in the measurement of the intake air amount due to the switching speed.

Conventionally, regarding the opening / closing control of the intake control valve such as the swirl control valve, for example, Japanese Patent Laid-Open No. 6-101484.
There is a first prior art of Japanese Patent Publication, and it is shown that the swirl control valve is controlled to a fully closed, intermediate opening and fully open opening based on an opening / closing control map preset by an engine load and an engine speed. Has been done. Further, in the second prior art of Japanese Patent Laid-Open No. 4-112932, the amount of fuel adhering to the wall surface changes as the intake state changes depending on the operating position of the swirl control valve,
Considering that there is a delay in the opening and closing of the swirl control valve,
It is shown that the fuel injection amount is corrected using a transient correction amount according to the state of adhesion of fuel after a lapse of a predetermined time from the start of operation of the swirl control valve. Furthermore, JP-A-4-1214
In the third prior art of Japanese Patent Publication No. 8 publication, a predetermined delay time is set when calculating the air amount when calculating the fuel injection amount, and the predicted value of the delay time ahead is set with respect to the throttle opening and the engine speed. It is shown that the cylinder inflow air amount is calculated based on these predicted values.

[0006]

By the way, in the first prior art described above, since the swirl control valve is only changed in three stages of full closing, full opening and intermediate opening, the switching speed is particularly high. When is fast, the variation of the air-fuel ratio cannot be suppressed due to the delay of the measurement of the intake air amount and the calculation of the fuel injection amount. In the second prior art, since it is premised that the swirl control valve is fully closed and fully opened, it is difficult to suppress the fluctuation of the air-fuel ratio. Further, since it is a method of delaying the calculation of the fuel injection amount with respect to the operation delay of the swirl control valve, it is not possible to cope with the delay in the measurement of the intake air amount when the switching speed is fast. The third prior art is not directly related to the opening / closing control of the intake control valve. Further, since a constant delay time is set when calculating the air amount, it is not possible to deal with a case where the switching speed changes and various delays in the measurement of the intake air amount change.

In view of the above points, the present invention is a system in which the intake control valve changes its opening based on a valve opening map set according to the engine operating state. The purpose of this is to properly correct and suppress fluctuations in the air-fuel ratio and prevent deterioration of drivability and exhaust gas.

[0008]

In order to achieve this object, an engine intake control device according to claim 1 of the present invention is provided in an intake system of an engine body 1 as shown in FIG. In an engine in which an intake control valve 24 that closes depending on the state to generate a swirl flow or a tumble flow, or opens and opens for full intake, and an injector 26 that injects fuel downstream of the intake control valve 24 are arranged according to the engine operating state. The opening degree of the intake control valve 24 is determined by the opening / closing control means C1 for controlling the opening / closing of the intake control valve 24 based on the valve opening degree, and the value obtained by subtracting the primary delay value of the intake air from the opening degree of the intake control valve 24. Correction amount calculation means C2 for calculating the primary delay correction amount when the valve is opened and closed, and fuel control means C3 for correcting and controlling the fuel injection amount of the injector 26 based on the primary delay correction amount. And wherein the door.

[0009]

Therefore, according to the first aspect of the present invention, the intake state is changed by opening and closing the intake control valve 24 depending on the engine operating state. At this time, fuel is injected by the injector 26. Then, for example, in the low load region, the intake control valve 2
When 4 is closed, a swirl flow or the like is generated in the cylinder by the intake air flow, which promotes the mixing of fuel and air and improves combustion. When the intake control valve 24 opens in the high load region, the intake air is fully opened to improve the engine output.

On the other hand, for example, when the engine load increases from a low load to a high load, the opening / closing control means C1 controls the intake control valve 24 to increase the valve opening degree. At this time, when the intake control valve 24 suddenly opens and the primary delay of the intake air amount measurement becomes large, the correction amount calculation means C2 subtracts the primary delay value of the intake air from the valve opening of the intake control valve 24. The first-order lag correction amount at the time of opening / closing the valve is a positive value and calculated in an inverse relationship to the first-order lag, and the fuel control amount C3 increases and corrects the fuel injection amount of the injector 26. Therefore, the delay of the measurement of the intake air amount is compensated by the increase of the fuel injection amount, so that the fluctuation of the air-fuel ratio is effectively suppressed. Even when the engine load decreases, when the intake control valve 24 is closed abruptly, the primary delay correction amount at the time of opening / closing the valve becomes a negative value, and the fuel injection amount is reduced and corrected. Therefore, also in this case, the delay amount of the measurement of the intake air amount is compensated by the reduction of the fuel injection amount, and thus the fluctuation of the air-fuel ratio is effectively suppressed.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 2, the overall configuration of the engine for tumble control will be described. Reference numeral 1 denotes an engine body, a piston 3 is movably inserted into a cylinder 2, and an intake port 6 having an intake valve 5 and an exhaust port 8 having an exhaust valve 7 are provided in the combustion chamber 4. The exhaust port 8 communicates with an exhaust pipe 9, and the exhaust pipe 9 is provided with a catalyst 10 for purifying exhaust gas.

In the intake system, the air cleaner 15 is connected to the surge tank 17 via the throttle valve 16, and the surge tank 17 is connected to the intake port 6 via the intake pipe 18. Further, the throttle valve 16 includes an idle control valve 1
1, the passage 12 having a bypass passage 1 is communicated with the intake pipe 1
The tumble generating means 20 is provided in the intake port 6 and the intake port 6.

The tumble generating means 20 has a partition wall 2 inside the region extending from the intake pipe 18 to the vicinity of the intake valve 5 of the intake port 6.
1 is provided. The partition wall 21 is installed so as to divide the inside of the port into an upper passage 22 and a lower passage 23 for intake air flowing in the axial direction of the cylinder center. And the lower passage 2
3, a tumble control valve 24 is provided with an electromagnetic actuator 25 so as to be opened and closed, and by closing and sucking only from the upper passage 22, a tumble flow swirling in the axial direction in the cylinder is generated by the intake flow. , It is possible to open and take a large amount of air. Further, due to the presence of the partition wall 21, the upper passage 22 which is always in communication with the intake pipe 18
An injector 26 is installed on the side of the so as to inject fuel into the intake port 6.

The electronic control system includes a crank angle sensor 30 for detecting the engine speed N, an air flow meter 31 for detecting the intake air amount Q, a throttle opening sensor 32 for detecting the throttle opening θ, and an air-fuel ratio state. O to detect
It has two sensors 33 and the like. These sensor signals are input to the control unit 40 and processed, and an opening / closing signal is output to the actuator 25 and an injection signal is output to the injector 26.

A functional block diagram of the control unit 40 will be described with reference to FIG. The tumble control valve opening / closing control system 41 will be described. The tumble control valve opening / closing control system 41 has an operating region detecting means 42 for inputting the engine speed N and the throttle opening θ, and determines the operating region based on the relationship between the two. Opening / closing control means 4 via map setting means 44
Enter in 3. The opening / closing control means 43 is the map setting means 4
By referring to the valve opening map of No. 4 with interpolation calculation, the valve opening according to the operating region is set. Then, the valve opening signal is output to the actuator 25 by the driving means 45 to control the opening and closing of the tumble control valve 24.

In the valve opening map, as shown in FIG. 4, the low load area in which the throttle opening θ is small is fully closed with the valve opening of 0% and the tumble mode is in the high load area in which the throttle opening θ is large. The fully open intake mode is set with the valve opening being 100%. The tumble mode is wide on the low speed side of the engine speed N, and the full open intake mode is wide on the high speed side. In addition, a merged mode, which is an intermediate state between the tumble mode and the fully open intake mode, is set in the middle load range with an intermediate valve opening.
And an increasing function with respect to the engine speed N.
As a result, when the throttle opening θ and the engine speed N increase / decrease depending on the driving and running conditions, it is possible to change the state of the intake air flow even when the opening changes and the merge mode is in effect.

An air-fuel ratio correction control system 46 is provided in order to prevent the air-fuel ratio from changing due to the switching speed even when the mode is switched by changing the opening of the tumble control valve 24. Here, the fuel injection amount Ti is the intake air amount Q and the engine speed N measured by the air flow meter 31.
Although the air flow meter 31 and the tumble control valve 24 are apart from each other, the intake air amount Q is measured in a first-order lag state, and when the switching speed is fast, the intake air amount Q is measured and the fuel injection amount is calculated. The calculation of Ti will not be in time. Therefore, when the valve opening changes, an air-fuel ratio fluctuation model is created to compensate for the primary delay of the measurement of the intake air amount Q,
The fuel injection amount Ti may be corrected based on this air-fuel ratio variation model.

Therefore, the air-fuel ratio correction control system 46 has an air-fuel ratio variation model creating means 47 for inputting the valve opening according to a map according to the operating region. Then, the first-order lag value VSN of the valve opening is calculated as follows from the valve-opening degree VS, the previous value VSNo of the first-order lag, and the idle constant a. VSN = | (a-1) .VSNo + VS | / a Here, the air-fuel ratio variation model Hv that compensates for the first-order lag may be calculated as follows because the first-order lag value VSN may be subtracted from the valve opening degree VS. Hv = VS-VSN

The signal in the operating region is used as the correction coefficient setting means 4
8 to determine the correction coefficient Kv according to the operating region by referring to the map, and the correction coefficient Kv and the air-fuel ratio variation model H
v is input to the correction amount calculation means 49, and the correction amount HTCV when the valve is opened and closed is calculated as follows. HTCV = Kv · Hv (-1.0 <HTCV <1.
0) As a result, as the valve opens faster at the time of switching from tumble to full-open intake air and the primary delay in measuring the intake air amount Q increases, the correction amount H increases.
TCV has a large positive value. On the contrary, the correction amount HTCV becomes a larger negative value as the valve closes faster at the time of full open intake → tumble switching and the delay similarly increases.

Explaining the fuel injection control system 50,
The intake air amount Q and the engine speed N measured by the air flow meter 31 are input to the basic injection amount calculation means 51 to calculate the basic injection amount Tp (K · Q / N). The signal from the O2 sensor 33 is input to the feedback coefficient setting means 52 to detect the state of the air-fuel ratio and set the feedback coefficient LAMBDA according to lean or rich. The signal from the throttle opening sensor 32 is the fuel correction coefficient setting means 5
Input to 3 and correct coefficient COEF for acceleration, deceleration, etc.
Set. These basic injection amount Tp, coefficient LAMBD
A, COEF, and the correction amount HTCV at the time of opening and closing the valve are input to the fuel injection amount calculation means 54, and the fuel injection amount Ti is calculated as follows. Ti = Tp (1 + HTCV) / COEF / LAMBDA

As a result, as the valve opens faster and the primary delay in measuring the intake air amount Q increases during the above-described tumble → fully open intake switching, the fuel injection amount Ti is increased and corrected by the term of the correction amount HTCV having a larger positive value. It On the contrary, as the valve closes faster at the time of full-open intake-> tumble switching and the delay similarly increases, the fuel injection amount Ti is reduced and corrected by the term of the correction amount HTCV having a larger negative value. Then, the injection signal of the fuel injection amount Ti is configured to be output to the injector 26 by the drive unit 55.

Next, the operation of this embodiment will be described. First, air corresponding to the opening of the throttle valve 16 flows into the surge tank 17 from the air cleaner 15 when the engine is operating. Further, fuel is injected by the injector 26 through the upper passage 22 which is always in communication with the intake port 6, and the air and the fuel are supplied to the cylinder 2 of the engine body 1 when the intake valve 5 is opened in the intake stroke. Then, the air-fuel mixture burns in the explosion stroke, and this combustion gas is discharged to the exhaust pipe 9 via the exhaust port 8 when the exhaust valve 7 opens in the exhaust stroke, and the exhaust gas passes through the catalyst 10. Then, harmful components are removed and purified.

During this engine operation, the control unit 40
The operating range detection means 42 determines the operating range based on the throttle opening θ and the engine speed N, and the opening / closing control means 43.
Then, the valve opening is selected with reference to the valve opening map of FIG.
Therefore, in the low load tumble mode, a fully closed signal with a valve opening of 0% is output to the actuator 25 and the tumble control valve 2
4 is closed and the lower passage 23 of the partition wall 21 is shut off. Therefore, air is sucked from only the upper passage 22 in the axial direction of the cylinder center, and a tumble flow swirling in the axial direction in the cylinder is generated by this intake flow. Then, the tumble flow promotes the mixing of air and fuel, and burns well to improve drivability, fuel efficiency, and the like.

In this tumble mode, the tumble control valve 24 remains fully closed, and the intake air amount Q changes gently so that there is almost no delay in its measurement. So VS = VSN
Therefore, even if HTCV = 0, it does not matter. Therefore, the fuel injection amount Ti calculated by the fuel injection amount calculation means 54 of the control unit 40 is the basic injection amount Tp based on the intake air amount Q and the engine speed N, the feedback coefficient LAMBDA based on the air-fuel ratio of the O2 sensor 33, the throttle opening θ, etc. The correction coefficient COEF is calculated according to the operating state and the like. Further, the air-fuel ratio of the air-fuel mixture is feedback-controlled to near the stoichiometric air-fuel ratio, so that the catalyst 10 effectively purifies the exhaust gas.

In the medium load merging mode, the valve opening degree map is set in the valve opening degree map shown in FIG. 4 according to the operating range by the throttle opening degree θ and the engine speed N, and this opening degree signal is output to the actuator 25. The tumble control valve 24 opens at a predetermined opening. Therefore, a predetermined intake air amount Q is surely introduced into the cylinder 2 by appropriately intake from the lower passage 23 of the intake port 6, and a tumble flow is generated by the intake flow from the upper passage 22. Therefore, both drivability and engine output are improved. In this case, when the engine speed N changes, the valve opening of the tumble control valve 24 also changes according to the valve opening map, but since it changes gently, the valve opening VS and the primary delay value V
Since the difference in SN is small, the air-fuel ratio fluctuation model HV also becomes small and the correction amount HTCV also approaches 0. For this reason, the fuel injection amount Ti is slightly corrected, but the influence on the air-fuel ratio is negligible, and the exhaust gas can be purified well.

In the high load full-open intake mode, the valve opening 10
A 0% full open signal is output to the actuator 25 to open the tumble control valve 24. Therefore, a large amount of air is taken into the intake port 6, and the fuel corresponding to the intake air intake amount is burned well in a state where the air utilization rate is high, and the engine output and the like are improved.
Even in this fully open intake mode, there is no change in the valve opening and the HT
Since CV = 0, the fuel injection amount Ti is calculated as in the tumble mode, and the exhaust gas can be purified.

Next, the control at the time of mode switching will be described with reference to the flowchart of FIG. 5 and the time charts of FIGS. 6 and 7. First, the throttle opening θ and the engine speed N are read in step S1 of the flowchart, and the tumble control valve 2 is read in step S2 with reference to the valve opening map of FIG.
The valve opening VS of 4 is determined. Therefore, the valve opening VS is set in an increasing function when the tumble → full-open intake air switching is performed in which the throttle opening θ increases.

In this case, when the throttle opening θ suddenly opens and the intake air amount Q also rapidly increases at time t1 in the time chart,
The valve opening VS rapidly increases and the tumble control valve 24 immediately opens to switch to the full-open intake mode side at a high switching speed. On the other hand, the intake air amount Q measured by the air flow meter 31 at this time increases with a first-order delay as indicated by the broken line in FIG.

After that, in step S3, the primary delay value VSN is
Is calculated by a function of the valve opening degree VS, the previous value VSNo of the first-order lag value, and the lean constant a, the first-order lag value VSN corresponding to the intake air amount measurement state is set as shown in FIG. 6B. It Then, in step S4, the air-fuel ratio variation model Hv
Is calculated by subtracting the first-order lag value VSN from the valve opening degree VS, and in step S5, the correction amount HTCV at the time of opening / closing the valve is calculated by multiplying the correction coefficient Kv and the air-fuel ratio variation model Hv.
Therefore, as shown in FIG. 6C, the correction amount HTCV has a positive value and is inversely related to the first-order lag value VSN, and becomes large at first and then gradually decreases. Thereafter, in step S6, the fuel injection amount Ti is calculated using the correction amount HTCV, and the fuel injection amount Ti is increased and corrected.

Therefore, the first-order lag amount of the intake air amount Q measured as shown by the broken line in FIG. 6 (a) is compensated by the increase in the fuel injection amount Ti by the correction amount HTCV in FIG. 6 (c). The fuel injection amount Ti increases stepwise corresponding to the actual intake air amount Q as shown in FIG. 6 (d). Therefore, the air-fuel ratio is suppressed from changing to the lean side as indicated by the alternate long and short dash line in FIG. 6 (e), and is almost constant as indicated by the solid line, and combustion and exhaust gas purification are improved.

When the switching speed is slow, the tumble control valve 2
4 gradually opens based on the map valve opening degree VS as shown in the time chart of FIG. 7. Therefore, the fluctuation range of the intake air amount Q becomes small, and the smooth switching is performed in the state where the torque shock is small. At this time, there is little delay in the measurement of the intake air amount Q, and the correction amount HTCV at the time of valve opening and closing becomes correspondingly small, and the fluctuation of the air-fuel ratio is suppressed by slightly correcting the fuel injection amount Ti. .

Next, a description will be given of the case where the full-open intake air → tumble is changed when the throttle opening θ decreases. In this case, when the throttle opening θ is suddenly closed at time t2 in the time chart of FIG. 6, the valve opening VS is rapidly reduced, the tumble control valve 24 is immediately closed, and the tumble mode side is switched at a high switching speed. Also at this time, the intake air amount Q measured by the air flow meter 31 decreases with a first-order lag as shown by the broken line in FIG. The first-order lag value VSN is shown in FIG.
As shown in FIG. 6C, the correction amount HTCV at the time of opening / closing the valve is a negative value and is calculated in the inverse relationship with the primary delay value VSN. The fuel injection amount Ti is reduced and corrected using the correction amount HTCV.

Therefore, the primary delay amount of the intake air amount Q measured as shown by the broken line in FIG. 6 (a) is similarly compensated by the reduction of the fuel injection amount Ti by the correction amount HTCV in FIG. 6 (c),
As a result, the fuel injection amount Ti decreases stepwise corresponding to the actual intake air amount Q as shown in FIG. Therefore, the air-fuel ratio is suppressed from fluctuating toward the rich side as indicated by the alternate long and short dash line in FIG. 6 (e), and combustion and exhaust gas purification are improved.

Also in this case, when the switching speed is slow, the tumble control valve 24 is gradually closed and smoothly switched based on the map valve opening VS as shown in the time chart of FIG. At this time, there is little delay in the measurement of the intake air amount Q, and the correction amount HTCV at the time of valve opening and closing becomes correspondingly small, and the fluctuation of the air-fuel ratio is suppressed by slightly correcting the fuel injection amount Ti. .

Although the embodiment of the present invention has been described above, the invention can be similarly applied to the case of a swirl control valve that generates a swirl flow as an intake control valve. Equipped with intake control valve,
Any engine can be applied as long as it measures the amount of intake air with an air flow meter and injects fuel.

In the embodiment, the case where the intake control valve is opened / closed on the basis of the valve opening map set according to the engine operating state has been described, but the intake control valve is also fully closed / opened by the switching line. Can be adapted. The correction amount at the time of opening / closing the valve can be directly determined by the air-fuel ratio fluctuation model.

[0037]

As described above, in the engine intake control device according to claim 1 of the present invention, in the system in which the intake control valve is opened / closed to generate a swirl flow, a tumble flow, or a fully open intake, The opening degree of the intake air is determined by referring to the valve opening map of the intake control valve according to the engine operating state, and the opening and closing control means for controlling the opening and closing of the intake control valve by this valve opening degree and the primary opening of the intake air from the opening degree of the intake control valve. Since the configuration is provided with the correction amount calculation means for calculating the primary delay correction amount at the time of opening / closing the valve with the value obtained by subtracting the delay value, and the fuel control means for correcting and controlling the fuel injection amount of the injector based on the primary delay correction amount. , The value obtained by subtracting the first-order lag value from the valve opening of the intake control valve is used to calculate the first-order lag correction amount at the time of valve opening / closing corresponding to the air-fuel ratio fluctuation model to correct the fuel injection amount. Change The variation of the air-fuel ratio due to the delay in the measurement of the intake air amount when the air control valve is suddenly opened and closed, can be effectively suppressed. Therefore, it is possible to ensure good drivability and purification of exhaust gas.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an engine intake control device according to the present invention.

FIG. 2 is an explanatory diagram showing an overall configuration of an engine that performs tumble control as an embodiment of the present invention.

FIG. 3 is a functional block diagram of an electronic control system.

FIG. 4 is a diagram showing a valve opening map of a tumble control valve.

FIG. 5 is a flowchart showing control at the time of mode switching.

FIG. 6 is a time chart showing an operating state when the tumble control valve is opened and closed rapidly.

FIG. 7 is a time chart showing an operating state when the tumble control valve is gently opened and closed.

[Explanation of symbols]

 1 Engine Main Body 24 Tumble Control Valve (Intake Control Valve) 26 Injector C1 Open / Close Control Means C2 Correction Amount Calculation Means C3 Fuel Control Means

Claims (1)

[Claims] 1. An intake control valve, which is provided in an intake system of an engine body, is closed to generate a swirl flow or a tumble flow, or is opened to fully open the intake air, and an injector for injecting fuel downstream of the intake control valve. In the engine where and are arranged, the valve opening degree of the intake control valve is determined according to the engine operating state,
An opening / closing control means for controlling the opening / closing of the intake control valve according to the valve opening degree, and a correction amount calculation for calculating the primary delay correction amount during valve opening / closing with a value obtained by subtracting the primary delay value of the intake air intake from the valve opening degree of the intake control valve. An intake control device for an engine, comprising: a fuel injection amount control means for controlling the fuel injection amount of the injector based on the first-order delay correction amount.