JPH09158754A - Intake control device of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent worsening of the driveability in moving to the stationary or accelerated condition after deceleration of a vehicle in an intake control device of an internal combustion engine having an intake control valve. SOLUTION: An intake control valve 19 to be opened/closed by an actuator 20 is provided in an intake passage 2 between a surge tank 9 on the downstream side of a throttle valve 8 and an injector 4. An electronic control unit (ECU) 41 controls the intake control valve 19 so as to be closed in a relatively early stage in decelerating a vehicle, and closed in a relatively later stage in accelerating the vehicle. When the vehicle is decelerated, the ECU 41 opens an ISCV 11 after closing the intake valve 5, and feed the air into the intake passage 2 through a bypass intake passage 10. Thus, the pressure in the surge tank 9 is not dropped much, it does not take long before the air volume in the intake passage 2 reaches the desired value, and the intake air volume is not insufficient.

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 an internal combustion engine, and more particularly, to an intake control for an internal combustion engine having an intake control valve provided in an intake passage of the internal combustion engine, separately from a throttle valve. It relates to the device.

[0002]

2. Description of the Related Art Conventionally, various techniques have been proposed for an intake control device for an internal combustion engine, which has an intake control valve provided in an intake passage corresponding to each cylinder of the internal combustion engine, separately from the throttle valve. ing.

For example, in the technique disclosed in Japanese Patent Laid-Open No. 5-288059, the throttle valve is opened in conjunction with the accelerator pedal, and the intake control valve is controlled in closing timing by the load and the rotational speed of the engine. Then, during steady running of the vehicle, the intake control valve is closed at the target closing timing determined by the load and the rotational speed (FIG. 9).
(A)). The target closing timing is determined based on the estimated pressure in the surge tank according to the operating state at that time.

Further, when the vehicle accelerates, a predetermined delay occurs in the pressure tracking, so that the actual pressure in the surge tank becomes smaller than the estimated pressure. In this case, the intake control valve is closed with the intake control valve delayed from the target closing timing (see FIG. 9B). In this way, by delaying the target closing timing, the lack of intake air can be resolved. On the other hand, even during deceleration of the vehicle, there is a predetermined delay in following the pressure, and in this case, the actual pressure in the surge tank becomes larger than the estimated pressure. In this case, the intake control valve is closed earlier than the target closing timing (see FIG. 9C). In this way, by advancing the target closing timing, excessive intake can be suppressed.

[0005]

However, although the above technique can prevent the deterioration of drivability to some extent, it sufficiently prevents the deterioration of drivability in an engine equipped with a large-capacity surge tank, for example. Could not be achieved. That is, in the case where a large capacity surge tank is mounted, for example, when the vehicle is decelerated, the pressure in the surge tank decreases. In this case, the running state from deceleration to steady,
Alternatively, when shifting from deceleration to acceleration, in the above technique, the closing timing of the intake control valve is delayed than before. However, at this point, the air density in the surge tank is low, and the capacity of the tank is large, so it takes a considerable amount of time to reach the desired air quantity in the intake passage. . Therefore, as in the above technique, there is a possibility that the problem that a delay in tracking the amount of air in the intake passage may occur cannot be solved by merely delaying the closing timing of the intake control valve. As a result, drivability may still be deteriorated.

The present invention has been made in view of the above circumstances, and an object thereof is to intake an internal combustion engine having an intake control valve provided in an intake passage downstream of a surge tank, separately from a throttle valve. It is an object of the present invention to provide an intake control device for an internal combustion engine, which can prevent deterioration of drivability due to insufficient intake air amount when the vehicle shifts to a steady state or an accelerated state after deceleration of the vehicle.

[0007]

In order to achieve the above object, the present invention, as shown in FIG. 1, is driven at a predetermined timing in synchronization with the rotation of an internal combustion engine M1 mounted on a vehicle, An intake valve M4 for opening and closing an intake passage M3 communicating with the combustion chamber M2, a throttle valve M6 provided on the upstream side of a surge tank M5 located in the middle of the intake passage M3, and a downstream side of the surge tank M5.
An intake control valve M7 provided in the intake passage M3 and an actuator M8 for opening and closing the intake control valve M7.
And an intake state control means M9 for detecting the operating state of the internal combustion engine M1, and an intake control means M10 for controlling the actuator M8 based on the detection result of the operating state detection means M9. A device,
A target closing timing of the intake control valve M7 is calculated based on the detection result of the operating state detecting means M9, and the target closing timing of the intake control valve M7 is calculated at least when the vehicle is decelerated. The intake control valve M7 is closed based on the target valve closing timing calculation means M11 that is set to be earlier than the steady state and acceleration of the vehicle, and the target closing timing calculated by the target valve closing timing calculation means M11. A valve closing control means M12 for controlling the actuator M8 so that the intake air at least between the downstream of the throttle valve M6 and the intake control valve M7 after the intake valve M4 is closed when the vehicle is decelerated. Intake amount increasing means M1 for supplying air into the passage M3
The main point is that 3 and 3 are provided.

According to the above structure, the intake valve M4 is
It is driven at a predetermined timing in synchronization with the rotation of the internal combustion engine M1, and opens and closes the intake passage M3 leading to the combustion chamber M2. Further, by opening and closing a throttle valve M6 provided in the intake passage M3 upstream of the surge tank M5,
Basically, the amount of intake air supplied to the internal combustion engine M1 can be adjusted. Further, on the downstream side of the surge tank M5, the intake control valve M7 provided in the intake passage M3 is opened / closed by the operation of the actuator M8. By this opening / closing, intake control can be executed separately from opening / closing of the throttle valve M6. That is, generally, the operating state detecting means M9 detects the operating state of the internal combustion engine M1, and the intake control means M10 controls the actuator M8 based on the detection result.

In the present invention, the target valve closing timing calculating means M11 calculates the target closing timing of the intake control valve M7 based on the detection result of the operating state detecting means M9. Particularly, at least when the vehicle is decelerated, the target closing timing of the intake control valve M7 is set to be earlier than when the vehicle is stationary and when the vehicle is accelerating. Then, in the valve closing control means M12, the actuator M8 is controlled and the intake control valve M7 is closed based on the target closing timing calculated by the target valve closing timing calculation means M11. Therefore, during deceleration of the vehicle, the intake control valve is closed relatively early, so that excessive intake can be suppressed and the intake air amount can be optimized. Further, when shifting from the deceleration to the steady state or the acceleration, the valve closing timing is delayed as compared with the deceleration, and the intake shortage is resolved.

By the way, for example, a large capacity surge tank M
When the vehicle is decelerated in the case where the vehicle No. 5 is mounted, the pressure in the surge tank M5 may decrease. In this case, the running state from the deceleration state to the steady state,
Alternatively, when the deceleration state shifts to the acceleration state, conventionally, the air density in the surge tank is low and its capacity is large, so that the air amount in the intake passage reaches the desired air amount. It took a lot of time. But,
In the present invention, when the vehicle is decelerated, after the intake valve M4 is closed, the intake amount increasing means M13 supplies air into the intake passage M3 at least between the downstream side of the throttle valve M6 and the intake control valve M7. It For this reason,
The pressure in the surge tank M5 does not drop so much. Therefore, even if the air conditioner enters the steady state or the acceleration state thereafter, it does not take much time until the air amount in the intake passage reaches the desired air amount, and the insufficiency of the intake air amount itself can be avoided. .

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) A first embodiment in which the intake control device for an internal combustion engine according to the present invention is embodied in a gasoline engine will be described in detail below with reference to FIGS.

FIG. 2 is a schematic configuration diagram showing an intake control device for an engine mounted on a vehicle in this embodiment. As shown in the figure, the engine 1 as an internal combustion engine
The outside air is taken in from the air cleaner 3 through the intake passage 2. Further, the engine 1 takes in the fuel injected from the injector 4 provided for each cylinder in the vicinity of the intake port 2a at the same time as taking in the outside air. Then, a mixture of the taken-in fuel and the outside air is introduced into the combustion chamber 1a through the intake valve 5 provided for each cylinder, and exploded and burned in the combustion chamber 1a to obtain a driving force. Further, the exhaust gas after the explosion and combustion is led out of the combustion chamber 1a via the exhaust valve 6 to the exhaust passage 7 where the exhaust manifold for each cylinder is gathered, and is discharged to the outside.

A throttle valve 8 which is opened / closed in association with the operation of an accelerator pedal (not shown) is provided in the intake passage 2. And this throttle valve 8
Is opened and closed, the amount of air taken into the intake passage 2 is adjusted. On the downstream side of the throttle valve 8,
A surge tank 9 for smoothing the pulsation of the intake air is provided. However, the surge tank 9 according to the present embodiment
Has a relatively large capacity.

In the middle of the intake passage 2, the bypass intake passage 1 that bypasses the throttle valve 8, that is, connects the upstream side and the downstream side of the throttle valve 8 with each other.
0 is provided. And this bypass intake passage 1
In the middle of 0, a linear solenoid type idle speed control valve (ISCV) 11 for adjusting the flow rate of air flowing through the passage 10 is provided. This I
In the SCV 11, the solenoid 11a is basically duty-controlled when the throttle valve 8 is closed and the engine 1 is in the idle state. The duty ratio is controlled to open and close (drive) the ISCV 11 as appropriate. By this opening and closing, the air flow rate (intake air amount) of the bypass intake passage 10 is adjusted. The adjustment of the intake air amount controls the engine speed NE during idling.

In the intake passage 2, the throttle valve 8
A throttle sensor 22 for detecting the opening degree (throttle opening degree) TA is provided in the vicinity of, and an idle switch 23 for detecting an idle state by "turning on" when the throttle valve 8 is fully closed. It is provided.

Further, the surge tank 9 has the same tank 9
An intake pressure sensor 24 that communicates with the intake air pressure (intake pressure) PiM to detect the intake air pressure (intake pressure) PiM is provided. An intake air temperature sensor 21 is provided in the surge tank 9, and the intake air temperature THA is detected by the intake air temperature sensor 21.

On the other hand, an oxygen sensor 25 for detecting the oxygen concentration OX in the exhaust gas is provided in the exhaust passage 7. Further, the engine 1 is provided with a water temperature sensor 26 for detecting the temperature (cooling water temperature) THW of the cooling water.

An ignition signal distributed by a distributor 13 is applied to an ignition plug 12 provided for each cylinder of the engine 1. The distributor 13 distributes the high voltage output from the igniter 14 to each of the ignition plugs 12 in synchronization with the crank angle of the engine 1. The ignition timing of each of the ignition plugs 12 is the high voltage output timing from the igniter 14. Is determined by

The distributor 13 is provided with a rotation speed sensor 27 for detecting the rotation speed (engine speed) NE of the engine 1 from the rotation of a rotor (not shown) built in the distributor 13. The distributor 13 is also provided with a crank angle sensor 28 for detecting a change in the crank angle of the engine 1 at a predetermined rate according to the rotation of the rotor.

In addition, the automatic transmission 15 drivingly connected to the engine 1 is provided with a vehicle speed sensor 29. The vehicle speed sensor 29 is capable of detecting the vehicle speed (vehicle speed) SPD at that time and outputting a signal indicating the value.

In addition, inside the automatic transmission 15,
A neutral start switch 30 is provided.
The neutral start switch 30 detects that the current shift position ShP is in a neutral range [N range (including P range)]. That is, it is possible to detect whether the current shift position ShP is in the N range or the drive range (D range).

Furthermore, in the present embodiment, a known exhaust gas circulation (EGR) device 16 is provided. The EGR device 16 includes an EGR passage 17 and an EGR valve 18 provided in the passage 17. EG
The R passage 17 is provided so as to connect the intake passage 2 on the downstream side of the throttle valve 8 and the exhaust passage 7. Further, the EGR valve 18 has a valve seat, a valve body, and a step motor (all not shown) built therein. EGR
The opening degree of the valve 18 is changed by the step motor intermittently displacing the valve body with respect to the valve seat. Then, when the EGR valve 18 is opened, a part of the exhaust gas discharged into the exhaust passage 7 flows into the EGR passage 17. The exhaust gas flows into the intake passage 2 via the EGR valve 18. That is, a part of the exhaust gas is generated by the EGR device 1
6 to recirculate into the intake mixture. At this time, EG
The recirculation amount of the exhaust gas is adjusted by adjusting the opening degree of the R valve 18.

In the present embodiment, an intake control valve 19 is provided in the intake passage 2 downstream of the throttle valve 8 between the surge tank 9 and the injector 4 so as to be openable and closable. The intake control valve 19 is provided for each cylinder. Further, the intake control valve 19 can be continuously opened and closed by an actuator 20 (electromagnetic oscillating device, rotary device, etc.) driven by duty control.

Further, in the present embodiment, the exhaust passage 7
A NOx absorption decomposition catalyst 31 is provided midway. The NOx absorption / decomposition catalyst 31 absorbs NOx in the air-fuel ratio lean exhaust gas and releases NOx in the air-fuel ratio rich or stoichiometric exhaust gas.

Then, each of the sensors 21, 22, 24 ...
The operating state and the like of the engine 1 are appropriately detected by the engine 29, the idle switch 23, the neutral start switch 30, and the like, and these constitute an operating state detecting means.

Further, each injector 4, solenoid 11a for ISCV 11, igniter 14, EGR valve 1
8 and the actuator 20 of the intake control valve 19 are electrically connected to an electronic control unit (hereinafter, simply referred to as “ECU”) 41, and their drive timing is controlled by the operation of the ECU 41. The ECU 41 constitutes intake control means, target valve opening timing calculation means, valve closing control means, and intake amount increasing means.

The ECU 41 includes the intake air temperature sensor 21, the throttle sensor 22, and the idle switch 2 described above.
3, intake pressure sensor 24, oxygen sensor 25, water temperature sensor 2
6, a rotation speed sensor 27, a crank angle sensor 28, a vehicle speed sensor 29, and a neutral start switch 30 are connected to each other. Therefore, the ECU 41 controls the sensors 21, 22, 24 to 29 and the idle switch 2
3 and the output signal from the neutral start switch 30, etc., the injector 4 and the solenoid 11a.
(ISCV11), igniter 14, EGR valve 18
The actuator 20 (the intake control valve 19) and the like are preferably controlled.

Next, the configuration of the ECU 41 will be described with reference to the block diagram of FIG. The ECU 41 includes a central processing unit (CPU) 42, a read-only memory (ROM) 43 in which a predetermined control program, a map, and the like are stored in advance, a CPU 42
A random access memory (RAM) 44 for temporarily storing the calculation results of the above, a backup RAM 45 for storing previously stored data, and the like. The ECU 41
Are the external input circuit 46 and the external output circuit 47
And the like are connected by a bus 48 to constitute a logical operation circuit.

The external input circuit 46 includes the intake air temperature sensor 21, the throttle sensor 22, and the idle switch 2 described above.
3, intake pressure sensor 24, oxygen sensor 25, water temperature sensor 2
6, a rotation speed sensor 27, a crank angle sensor 28, a vehicle speed sensor 29, a neutral start switch 30, and the like are connected to each other. Then, the CPU 42 reads output signals from the sensors 21, 22, 24 to 29, the idle switch 23 and the neutral start switch 30 via the external input circuit 46 as input values. Then, the CPU 42 based on these input values, the injector 4, the solenoid 11a, which is connected to the external output circuit 47,
The igniter 14, the EGR valve 18, the actuator 20 (the intake control valve 19), etc. are suitably controlled. The learning values and flags in this embodiment are stored in the backup RAM 45 described above.

Next, of the processing executed by the ECU 41, the processing contents centering on the opening / closing control of the intake control valve 19 and the opening / closing control of the ISCV 11 will be described. First,
The process for controlling the intake control valve 19 will be described with reference to FIG.
The flowchart of FIG. 6 will be described with reference to the timing chart of FIG. FIG. 4 is a flowchart showing an “intake control valve control routine” executed by the ECU 41 to control the actuator 20 and the closing timing of the intake control valve 19 after the engine 1 is started. It is executed by interruption at a predetermined crank angle.

When the processing shifts to this routine, first, at step 101, the ECU 41 causes the sensors 21
The detection signals from 30 to 30 (for example, throttle opening TA, engine speed NE, etc.) are read.

Then, in the following step 102,
The basic target valve closing timing Tc is calculated based on the engine speed NE and the throttle opening TA read this time. Here, the basic target valve closing timing Tc is the engine speed NE and the throttle opening TA
Is set by referring to the two-dimensional map that defines the basic target valve closing timing Tc for

Next, at step 103, the smoothed value TACRT of the throttle opening TA is calculated. The smoothed value TACRT is calculated based on, for example, the amount of change in the throttle opening TA at that time.

Subsequently, at step 104, a value obtained by subtracting the smoothed value TACRT calculated this time from the throttle opening TA read this time is set as the load fluctuation amount ΔTA1.

Further, in step 105, a predetermined value a1 previously set for the load fluctuation amount ΔTA1 calculated this time.
The value multiplied by is set as the correction term α1. For this reason,
When the throttle opening TA decreases from the previous opening, the vehicle is decelerating, and in this case, the load variation ΔTA1 and the correction term α1 have negative values. on the other hand,
When the throttle opening TA increases from the previous opening, the vehicle is accelerating, and in this case, the load fluctuation amount ΔTA
1 and the correction term α1 are positive values.

Then, in step 106, the timing obtained by adding the correction term α1 calculated this time to the basic target valve closing timing Tc calculated this time is set as a new target valve closing timing Tc1. And the ECU 41
Terminates the subsequent processing once.

As described above, in the "intake control valve control routine", the target valve closing timing Tc1 is set according to the operating state (engine speed NE and throttle opening TA) at that time. In particular, during deceleration of the vehicle, the target valve closing timing Tc1 is set to an earlier timing than that during steady state. Further, when the vehicle is accelerating, the target valve closing timing Tc1 is set to a timing later than that in the steady state.

Therefore, during deceleration of the vehicle, the intake control valve 1
Since the valve 9 is closed relatively early, excessive intake can be suppressed, and the intake air amount can be optimized. Also,
At the time of acceleration, the intake control valve 19 is closed relatively late, and the valve closing timing is relatively delayed, so that the intake shortage can be resolved.

By the way, in the case where the surge tank 9 having a large capacity is mounted as in this embodiment, when the vehicle is decelerated, the pressure in the surge tank 9 decreases. In this case, when the traveling state transitions from the deceleration state to the steady state, or from the deceleration state to the acceleration state, the air density in the surge tank has been reduced in the past and the capacity is large. It took a considerable time for the air amount to reach the desired air amount.

On the other hand, in the present embodiment, the above-mentioned problems are solved by performing the following control. That is, FIG. 6 shows that after the engine 1 is started, the ISCV 11 (the solenoid 11
It is a flowchart which shows the "ISCV control routine" performed by ECU41 in order to control a) and control an intake air quantity, and is performed by interruption at a predetermined crank angle.

When the processing shifts to this routine, first, at step 201, the ECU 41 causes the sensors 21
Detection signals from, for example, throttle opening TA, engine speed NE, idle switch signal, intake pressure Pi
M)) is read.

Then, in the following step 202,
It is determined whether or not the idle switch signal read this time is "off". If the idle switch signal is on, the throttle opening TA is currently "0", and in order to perform the idle speed control thereafter, in step 203, for the time being, ISCV
The target opening degree ISCT1 of 11 is set to the fully open value ISCMAX, and the subsequent processing is once ended. And then
In a separate routine, the solenoid 11a is duty-controlled and the duty ratio is controlled so that the ISCV 11 is appropriately opened / closed (driven). That is,
Idle speed control is executed. However, the description of the control contents of the idle speed control is omitted here.

On the other hand, when the idle switch signal is off in step 202, the process proceeds to step 204 to control the pressure in the intake passage 2 including the surge tank 9 thereafter.

In step 204, the target opening ISCT1 of ISCV11 is set based on the engine speed NE and the throttle opening TA read this time. Here, the target opening ISCT1 is set by referring to a two-dimensional map that defines the target opening ISCT1 with respect to the engine speed NE and the throttle opening TA at that time.

Next, at step 205, it is judged whether or not the intake pressure PiM read this time is equal to or greater than a predetermined value (for example, "650 mmHg" in this embodiment). When the intake pressure PiM is equal to or higher than the predetermined value, it is determined that the pressure in the intake passage 2 including the surge tank 9 has not dropped so much, and the subsequent processing is temporarily terminated. Further, when the intake pressure PiM is less than the predetermined value, it is determined that the above-described trouble may occur, and the target opening ISCT1 of the ISCV11 calculated and set this time is multiplied by “1 + β” (where β is “0 , Which is a constant larger than 0, preferably 0 <β <0.2) is newly set as the target opening ISCT1 of the ISCV11.

After that, the ECU 41 shifts the processing to step 205 again and determines whether the intake pressure PiM is equal to or higher than a predetermined value. Then, the processes of steps 205 and 206 are repeated until the process is determined in step 205.

As described above, in the "ISCV control routine", when the throttle valve 8 is opened, the throttle valve 8 and the intake control valve 19 are opened.
The pressure in the intake passage 2 (including the surge tank 9) between and is controlled to be maintained at a predetermined value or more by the control of the ISCV 11. Then, in a separate routine, when the vehicle is decelerated, control is performed so that the opening degree of the ISCV 11 becomes the target opening degree ISCT1 set in this routine after the intake valve 5 is closed. .

As described above, according to the present embodiment, as shown in FIG. 5, during deceleration of the vehicle, the intake control valve 19 is closed relatively early to suppress excessive intake. Further, during acceleration, the intake control valve 19 is closed relatively late, so that insufficient intake can be resolved.

By the way, in the case where, for example, a large capacity surge tank 9 is mounted as in the present embodiment, as described above, when the vehicle is decelerated, the pressure in the surge tank 9 decreases, And since its capacity is large, when it shifts to the steady state or the acceleration state thereafter,
It may take time until the amount of air in the intake passage 2 reaches the desired amount of air (the portion shown by the broken line in FIG. 5).

However, in this embodiment, when the vehicle is decelerated, after the intake valve 5 is closed, the ISCV1
When 1 is opened, air is supplied through the bypass intake passage 10 into at least the intake passage 2 between the downstream side of the throttle valve 8 and the intake control valve 19. Therefore, as shown by the solid line in FIG. 5, the pressure in the surge tank 9 does not drop so much (in the present embodiment, the pressure in the surge tank 9 is held at a value of “650 mmHg”, which is relatively close to the standby state. ). Therefore, after deceleration,
Even if the air flow amount in the intake passage 2 reaches the desired air amount even if the steady state or the acceleration state is entered, it does not take much time and the insufficient intake amount itself can be avoided. As a result, it is possible to prevent deterioration of drivability due to a shortage of the intake air amount.

Further, in the present embodiment, unlike the prior art in which the correction term is calculated based on the difference between the intake pressure PiM and the estimated pressure and the valve closing timing is set based on the correction term, the throttle opening is opened. The correction term α1 is calculated based on the variation amount of the degree TA and the valve closing timing is corrected.
Therefore, when the pressure change in the surge tank 9 is small, the control can be executed without performing complicated calculation and estimation.

(Second Embodiment) Next, a second embodiment of the present invention will be described with reference to FIG. However, since the configuration and the like of the present embodiment are almost the same as those of the above-described first embodiment, the same members and the like are denoted by the same reference numerals and description thereof is omitted. Then, in the following, differences from the second embodiment will be mainly described.

The present embodiment is different from the first embodiment in the control for calculating the target valve closing timing Tc. Then, next, the content of the control will be described with reference to the flowchart of FIG. 7. FIG.
4 is a flowchart showing an "intake control valve control routine" executed by the ECU 41, which is executed by interruption at a predetermined crank angle.

When the processing shifts to this routine, first, at step 301, the ECU 41 causes the sensors 21
30 to 30 (for example, throttle opening TA, engine speed NE, etc.) are read, and the subsequent step 302
In, the basic target valve closing timing Tc is calculated based on the engine speed NE and the throttle opening TA read this time. Here, the basic target valve closing timing Tc is set by referring to a two-dimensional map that defines the basic target valve closing timing Tc for the engine speed NE and the throttle opening TA at that time. Up to this point, the same processing as in the first embodiment is executed.

Next, in step 303, a value obtained by subtracting the throttle opening TA _i-1 read last from the currently read throttle opening TA _i as opening deviation DerutaTA2.

Further, in step 304, the opening deviation ΔTA2 calculated and set this time is set to a predetermined value a.
A value obtained by multiplying by 2 is set as the correction term α2. Therefore, when the throttle opening TA decreases from the predetermined opening, the vehicle is decelerating, and in this case, the opening deviation Δ
TA2 and the correction term α2 have negative values. On the other hand, when the throttle opening TA increases from the predetermined opening, the vehicle is in acceleration, and in this case, the opening deviation ΔTA2 and the correction term α2 are positive values.

Then, in step 305, a timing obtained by adding the correction term α2 calculated this time to the basic target valve closing timing Tc calculated this time is set as a new target valve closing timing Tc2. And the ECU 41
Terminates the subsequent processing once.

As described above, also in this "intake control valve control routine", the target valve closing timing Tc2 is set according to the operating state (engine speed NE and throttle opening TA) at that time (FIG. 5). See the bottom).
Then, even when the target valve closing timing Tc2 is set in this manner, the same operational effects as those of the above-described first embodiment are achieved.

(Third Embodiment) Next, a third embodiment of the present invention will be described with reference to FIG. However, in the configuration and the like of the present embodiment, the same members and the like as those in the above-described first and second embodiments will be denoted by the same reference numerals, and the description thereof will be omitted. The differences from the first and second embodiments will be mainly described.

As shown in FIG. 8, in the present embodiment, from the intake passage 2 on the downstream side of the intake control valve 19 provided corresponding to each cylinder and on the upstream side of the intake valve 5,
A branch passage 33 is provided, and the branch passages 33 join each other and finally communicate with a vacuum tank 34 for braking. In addition, each branch passage 33
A check valve 35 is provided at the boundary between the intake passage 2 and the intake passage 2.

The above-mentioned configuration is such that, when the configurations of the first and second embodiments are adopted, the degree of decrease in the negative pressure in the surge tank 9 is relatively small.
Therefore, the purpose is to separately secure a negative pressure for braking.

That is, in the present embodiment, for example, after a predetermined time elapses after the brake pedal is depressed,
Alternatively, if a fuel cut is required, the ECU
By 41, the control for fixing the intake control valve 19 to the fully closed state for a fixed time is executed. By this full closing control, a negative pressure is secured on the downstream side of the intake control valve 19, in which case the check valve 35 is opened, and the negative pressure is secured in the vacuum tank 34. . Therefore, as in the first and second embodiments described above,
Even if the degree of decrease in the negative pressure in the surge tank 9 becomes relatively small, it is possible to sufficiently secure the negative pressure required for braking by adopting the configuration of the present embodiment.

The present invention is not limited to the above-mentioned embodiments, but may be configured as follows, for example. (1) In each of the above-mentioned embodiments, particularly the first embodiment,
Although the intake air amount is secured by controlling the opening of the ISCV 11, the control valve 8 is constituted by, for example, an electronically controlled throttle valve, and the throttle valve is momentarily fully opened during deceleration. ,
You may make it ensure an air volume. Further, a separate bypass passage and relief valve may be provided.

(2) In each of the above embodiments, particularly the first embodiment, the pressure in the surge tank 9 is set to, for example, "650".
Although the control so as to be “mmHg” or more is adopted, the control content may be opened to the atmosphere. Further, the above numerical values are not limited at all.

(3) In each of the above embodiments, the gasoline engine 1 is embodied as the internal combustion engine, but a vehicle equipped with a diesel engine may be embodied.

(4) In the third embodiment, the branch passage 33 is provided so as to correspond to all the cylinders. However, it is not always necessary to provide the branch passages 33 so as to correspond to all the cylinders. The negative pressure may be ensured. In such a case, cost increase can be suppressed.

(5) In the third embodiment, the intake control valve 19 is fixed in the fully closed state when the predetermined condition is satisfied, but it is not always required to be fully closed.
What is not stated in the claims of the claims,
The technical ideas that can be understood from the above-described embodiment will be described below along with their effects.

(A) In the intake control device for an internal combustion engine according to claim 1, means for ensuring a negative pressure for braking is provided in the intake passage between the intake control valve and the intake valve. It is characterized by that.

With such a structure, even if the degree of decrease in the negative pressure in the surge tank is relatively small in order to exert the effect of the present invention, a sufficient negative pressure required for braking is secured. It becomes possible to do.

(B) In the intake control device for an internal combustion engine according to claim 1 and the supplementary note (a), air is introduced into the intake passage between the downstream side of the throttle valve and the intake control valve by the intake amount increasing means. At least one of a bypass intake passage bypassing the throttle valve and an idle speed control valve provided in the passage is used to supply the electric power, and an electronically controlled throttle valve is used as the throttle valve. Is characterized by.

With such a structure, the function and effect of the present invention can be exhibited even in the existing device, and thus the increase in cost can be suppressed.

[0072]

As described in detail above, according to the present invention,
In an intake control device for an internal combustion engine that has an intake control valve provided in the intake passage downstream of the surge tank, separately from the throttle valve, when the vehicle decelerates and enters a steady state or an accelerated state, the intake air amount is insufficient. This has an excellent effect that it is possible to prevent deterioration of drivability due to.

[Brief description of the drawings]

FIG. 1 is a conceptual configuration diagram illustrating a basic conceptual configuration of the present invention.

FIG. 2 is a schematic configuration diagram showing an intake control device for an engine according to the first embodiment.

FIG. 3 is a block diagram showing an electrical configuration of an ECU and the like.

FIG. 4 is a flowchart showing an “intake control valve control routine” executed by the ECU.

FIG. 5 is a timing chart explaining the operation of the first and second embodiments.

FIG. 6 is a flowchart showing an “ISCV control routine” executed by the ECU.

FIG. 7 is a flowchart showing an “intake control valve control routine” executed by an ECU in the second embodiment.

FIG. 8 is a schematic diagram showing a configuration of an intake passage and the like according to a third embodiment.

FIG. 9 is a graph showing the opening characteristics of the intake valve and the intake control valve in the prior art, where
(B) is a timing chart showing acceleration and (c) is deceleration.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Engine as an internal combustion engine, 1a ... Combustion chamber, 2 ... Intake passage, 5 ... Intake valve, 8 ... Throttle valve, 19
... Intake control valve, 20 ... Actuator, 21 ... Intake temperature sensor that constitutes operating state detecting means, 22 ... Throttle sensor that constitutes operating state detecting means, 23 ... Idle switch that constitutes operating state detecting means, 24 ... Operating state Intake pressure sensor constituting detecting means 25 ... Oxygen sensor constituting operating state detecting means 26 ... Water temperature sensor constituting operating state detecting means 27 ... Rotation speed sensor constituting operating state detecting means 28 ... Operating state Crank angle sensor constituting detection means 29 ... Vehicle speed sensor constituting operation state detection means 30 ... Neutral start switch constituting operation state detection means 41 ... Intake control means, target valve opening timing calculation means, valve closing control An ECU that constitutes the means and the intake amount increasing means.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location F02D 41/14 320 F02D 41/14 320C

Claims (1)

[Claims] 1. An intake valve, which is driven at a predetermined timing in synchronism with rotation of an internal combustion engine mounted on a vehicle to open and close an intake passage communicating with a combustion chamber, and an upstream of a surge tank located in the middle of the intake passage. Side throttle valve, an intake control valve provided in the intake passage downstream of the surge tank, an actuator for opening and closing the intake control valve, and an operating state of the internal combustion engine is detected. An operating state detection means, based on the detection result of the operating state detection means, an intake control device of an internal combustion engine comprising an intake control means for controlling the actuator, based on the detection result of the operating state detection means, A target closing timing of the intake control valve is calculated, the target closing timing of the intake control valve being determined at least when the vehicle is decelerated. The intake valve is closed based on the target valve closing timing calculation unit that sets the engine speed to be earlier than the steady state and acceleration of the vehicle, and the target closing timing calculated by the target valve closing timing calculation unit. A valve closing control means for controlling the actuator, and when the vehicle is decelerated, air is supplied into the intake passage at least between the downstream side of the throttle valve and the intake control valve after the closing of the intake valve. An intake control device for an internal combustion engine, comprising: