JPH0914007A - Internal combustion engine air intake control device - Google Patents

Abstract

PURPOSE: To improve controlling accuracy and prevent occurrence of malfunction accompanying deterioration of accuracy of the air intake control device of an internal combustion engine incorporated with an air intake valve. CONSTITUTION: An air intake control valve 19 is provided between a surge tank 9 and an injector 4 inside the air intake passage of an engine 1 in an openable and closable manner. Intake-air temperature on the lower stream side of the air intake control valve 9, and on the upper stream side of the air intake valve 5 as well, is detected by an intake-air temperature sensor 21. An electronic control unit(ECU) 4 sets and regulates the opening and closing timing of the air intake control valve 19 based on the detected result. In addition, various controls such as fuel injection quantity are applied or the basis of the detected result and the like. Therefore, unlike conventional technique which provided the intake-air temperature sensor in the surge tank 9, temperature of the intake air conducted into an engine 1 combustion chamber 1a is accurately detected. Thus an actuator 20 and the like are given drive control on the basis of highly accurate intake-air temperature.

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 valve provided in an intake passage corresponding to each cylinder of the internal combustion engine, separately from the throttle valve. The present invention relates to an intake control device for an internal combustion engine.

[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 a racing engine or the like, the output torque in the high speed region is increased, but in the low and medium speed regions, the intake / exhaust efficiency decreases at the time of valve overlap. It is possible to increase the torque in the low-medium speed range by controlling the opening and closing of.

That is, as shown by the broken line in FIG. 17, the opening / closing behavior of the intake valve is normal (solid line in the figure).
Compared to, set a large working angle and a large lift amount, and open the intake valve early and close it late. Then, as shown by the chain double-dashed line in the figure, the opening / closing of the intake control valve is controlled. By executing such control, as shown by the chain double-dashed line in FIG. 18, the output torque in the high rotation speed region is significantly increased compared to the output torque in the normal state (solid line in the figure). At the same time, it is possible to improve the output torque and fuel efficiency in the middle and low rotation speed range at the same time.

A further known technique is Japanese Patent Laid-Open No. 4-3.
The thing disclosed by the 50324 gazette is mentioned. In this technique, the intake control valve is closed relatively early.
By performing such control, pumping loss can be reduced and fuel consumption can be improved.

In the above control, the intake air temperature in the surge tank is detected by the intake air temperature sensor, and the closing timing of the intake control valve is controlled based on the detection result and the like. More specifically, as the detected intake air temperature is lower, the degree of early valve closing is alleviated, and the valve closing timing is controlled to the retard side. By such control, when the intake air temperature is low, the intake air is heated, and the deterioration of combustion is prevented.

[0007]

However, the temperature of the intake air actually introduced into the combustion chamber of the engine is affected by adiabatic expansion and internal EGR, especially when the intake control valve is closed.
The temperature fluctuates depending on the gas or the like and is likely to be different from the temperature on the upstream side of the intake control valve. On the other hand, in the above-mentioned conventional technique, the closing control of the intake control valve is performed based on the detection result of the intake temperature sensor provided upstream of the intake control valve. Therefore, the temperature of the intake air actually introduced into the combustion chamber may not correspond to the intake air temperature detected by the intake air temperature sensor. When the temperature different from the actual intake air temperature is adopted and the valve closing control is performed as described above, the accuracy of the valve closing control may decrease.

Further, in the engine provided with the intake control valve, in addition to the intake control valve, the fuel injection amount control, the ignition timing control, and the EGR are performed as in a general engine.
Various controls such as (exhaust gas recirculation) control and fuel injection timing control can be executed. In this case as well, similar to the above-described technique, various controls were executed based on the detection result of the intake air temperature sensor upstream of the intake control valve. Therefore, when performing various controls other than the intake control valve, the control accuracy may be deteriorated.

The present invention has been made in view of the above-mentioned circumstances, and an object thereof is to provide an intake control valve provided in an intake passage corresponding to each cylinder of an internal combustion engine, separately from the throttle valve. It is an object of the present invention to provide an intake control device for an internal combustion engine, which can improve control accuracy and can prevent the occurrence of troubles due to the decrease in accuracy.

[0010]

In order to achieve the above object, in the invention described in claim 1, as shown in FIG. 1, a throttle valve M3 provided in the middle of an intake passage M2 of an internal combustion engine M1 is provided. An intake control valve M4 provided in an intake passage M2 corresponding to each cylinder of the internal combustion engine M3 downstream of the throttle valve M3, an actuator M5 for opening and closing the intake control valve M4, and the internal combustion engine Operating state detecting means M for detecting the operating state of M1
6 and the detection result of the operating state detecting means M6,
Intake control means M7 for controlling the actuator M5
An intake control device for an internal combustion engine, comprising: a control target control means M9 for controlling another control target M8 of the internal combustion engine M1 based on a detection result of the operating state detection means M6; At least one control content by the intake air control means M7 and the controlled object control means M9 is adjusted based on the intake air temperature detection means M10 for detecting the intake air temperature downstream of M4 and the detection result of the intake air temperature detection means M10. The gist is that the control content adjusting means M11 is provided.

[0011]

According to the configuration of the invention described in claim 1 above,
As shown in FIG. 1, the intake air amount supplied to the internal combustion engine M1 can be basically adjusted by opening and closing the throttle valve M3 provided in the intake passage M2 of the internal combustion engine M1.

Further, on the downstream side of the throttle valve M3, an intake passage M corresponding to each cylinder of the internal combustion engine M1.
The intake control valve M4 provided in
Is operated to open and close. By this opening and closing,
Intake control may be executed separately from the opening / closing of the throttle valve M3. That is, the operating state detecting means M6 detects various operating states including at least the temperature corresponding to the engine temperature of the internal combustion engine M1. Then, based on the detection result, the actuator M5 is controlled by the intake control means M7, whereby intake control can be performed.
Further, based on the detection result, another controlled object M8 of the internal combustion engine M1 is controlled by the controlled object control means M9.

In the present invention, the intake temperature on the downstream side of the intake control valve M4 is detected by the intake temperature detecting means M10. Then, based on the detection result, at least 1 by the intake control means M7 and the controlled object control means M9
The one control content is adjusted by the control content adjusting means M11. Therefore, the temperature of the intake air introduced into the combustion chamber of the internal combustion engine M1 can be accurately detected. Further, the actuator M5 (intake control valve M4) and the controlled object M8 can be controlled based on the highly accurate intake air temperature.

[0014]

【Example】

(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, an engine 1 as an internal combustion engine takes in outside air from an air cleaner 3 through an 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. Also, the exhaust gas after explosion and combustion is
From the combustion chamber 1a, an exhaust valve 6 is introduced to an exhaust passage 7 where the exhaust manifold for each cylinder is assembled, and the exhaust passage 7 is exhausted to the outside.

A throttle valve 8 which is opened / closed in conjunction 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.

In the middle of the intake passage 2, the bypass intake passage 1 bypassing the throttle valve 8, that is, connecting 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) θ 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 is provided. It is provided. Further, the surge tank 9 is provided with an intake pressure sensor 24 that communicates with the tank 9 and detects an intake air pressure (intake pressure) PiM.

On the other hand, an oxygen sensor 25 for detecting the oxygen concentration OX in the exhaust gas is provided in the middle of 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, a vehicle speed sensor 29 is provided in the automatic transmission 15 which is drivingly connected to the engine 1. 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 this embodiment, a known exhaust gas circulation (EGR) device 16 is provided. This EG
The R device 16 includes an EGR passage 17 and an EGR valve 18 provided in the middle of the EGR passage 17. The EGR passage 17 includes the intake passage 2 downstream of the throttle valve 8.
And the exhaust passage 7 are communicated with each other.
Further, the EGR valve 18 has a valve seat, a valve body, and a step motor (all not shown) built therein. The opening degree of the EGR valve 18 is changed by the step motor intermittently displacing the valve element with respect to the valve seat. And E
By opening the GR valve 18, a part of the exhaust gas discharged to the exhaust passage 7 flows to 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 recirculated into the intake air-fuel mixture by the EGR device 16. At this time, the recirculation amount of the exhaust gas is adjusted by adjusting the opening degree of the EGR valve 18.

In this embodiment, an intake control valve 19 is provided in the intake passage 2 between the surge tank 9 and the injector 4 so as to be openable and closable. Intake control valve 1
9 is provided for each cylinder. In addition, the intake control valve 19
Is an actuator 2 driven by duty control
0 (electromagnetic oscillating device, rotary device, etc.) can be continuously opened and closed. In addition, Engine 1
When the intake control valve 19 is stopped, the intake control valve 19 is maintained in a free state with a predetermined opening.

Further, in the present embodiment, the intake air temperature sensor which is conventionally provided in the vicinity of the air cleaner 3 is not provided, but instead, the intake control valve 16 is provided on the downstream side (but upstream of the intake valve 5). Side) in the intake passage 2,
An intake air temperature sensor 21 as an intake air temperature detecting means is provided. The intake air temperature sensor 21 detects an intake air temperature Tin that corresponds more to the intake air introduced into the combustion chamber 1a.

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, the solenoid 11a for the ISCV 11, the igniter 14, the 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, controlled object control means, and control content adjustment means. In addition, in this embodiment, each injector 4,
The control target is configured by the solenoid 11a for the ISCV 11, the igniter 14, the EGR valve 18, and the like.

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 structure 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, various processing contents centering on the opening control of the intake control valve 19 will be described. That is, after the engine 1 is started, control of the intake control valve 19 (actuator 20) and the like as described below is executed. Hereinafter, a process for performing the control will be described with reference to a flowchart of FIG. However, in this embodiment,
The basic opening / closing timing of the intake valve 5 is set to have a large working angle and a large lift amount as compared with the general opening / closing behavior of the intake valve, as described in the related art. That is, the intake valve 5 is opened early and closed late, so that the output torque in the high rotation speed region is significantly increased.

FIG. 4 shows "various control routines" executed by the ECU 41 after the engine 1 is started.
Is a flowchart showing the above, which is executed by a regular interruption every predetermined time.

When the processing shifts to this routine, first in step 001, the ECU 41 causes the sensors 21
Detection signals from 30 to 30 (for example, intake air temperature Tin, throttle opening θ, intake air pressure PiM, oxygen concentration OX, cooling water temperature THW, engine speed NE, vehicle speed SPD, shift position ShP, air conditioner operation signal, etc.) are read.

Then, in the following step 100,
The intake control valve 19 is controlled based on the detection signals read this time. Here, the control content of the intake control valve 19 will be described. That is, FIG. 5 is a "intake control valve control routine" which is a subroutine executed by the ECU 41.
It is a flowchart which shows. In step 101, the ECU 41 determines, based on a detection signal from the crank angle sensor 28 or the like, whether or not the present time is at the time of starting or within t seconds after starting (hereinafter, simply referred to as “starting time”).
That is, after the engine 1 is started, the ECU 41 starts counting, and certifies that the time is starting up until t seconds have elapsed. Further, when determining whether or not it is the moment of starting, the determination may be made based on a signal from a starter or the like not shown. When it is determined that the present time is the so-called starting time,
In step 102, the control for starting is separately executed, and the subsequent processing is temporarily ended.

If it is determined that the current time is not the so-called starting time, the routine proceeds to step 103, and the ROM is stored in advance.
The intake control valve 19 based on the map and the like stored in 42.
Calculate the opening and closing times of. For example, FIG. 6 is a map in which the relationship between the intake air temperature Tin and the closing timing at each time is determined for each throttle opening θ. As shown in this figure, the throttle opening θ and the intake air temperature Ti
The closing timing of the intake control valve 19 is set based on n. For example, when the throttle opening θ is relatively small, the higher the intake air temperature Tin, the more the closing timing shifts to the intake top dead center side.

Next, at step 104, the timer starts counting. Further, in the following step 105, it is determined whether or not the count value corresponds to the opening time calculated in step 103. And when it is determined that the count value does not yet correspond to the opening time,
In step 106, a close signal is output to the actuator 20. This output causes the intake control valve 19 to be closed.

If it is determined in step 105 that the count value corresponds to the opening timing, an open signal is output to the actuator 20 in step 107. This output causes the intake control valve 19 to be opened.

Next, at step 108, it is judged whether or not the count value corresponds to the closing time. When it is determined that the count value does not yet correspond to the closing timing, the process returns to step 107 and the actuator 2
An open signal is output to 0. Then, the processes of step 107 and step 108 are repeatedly performed until the count value corresponds to the closing time. Therefore, during this period, the open signal is continuously output to the actuator 20, and the intake control valve 19 is continuously opened.

If it is determined in step 108 that the count value corresponds to the closing time, a closing signal is output to the actuator 20 in step 109. This output causes the intake control valve 19 to be closed.

Then, in step 110, the ECU
41 clears the count value to "0" and temporarily ends the subsequent processing. In this way, in this "intake control valve control routine", it is determined whether or not it is at the time of so-called starting, and if it is determined other than at the time of starting, open / close control of the intake control valve 19 is executed. . At the time of this opening / closing control, the opening timing based on the intake air temperature Tin,
The closing time is calculated and set.

In this embodiment, on the downstream side of the intake control valve 19,
In addition, the intake air temperature Tin on the upstream side of the intake valve 5
Is detected by the intake air temperature sensor 21. Then, based on the detection result, the opening / closing timing of the intake control valve 19 can be set and adjusted. Therefore, unlike the conventional technique in which the intake temperature sensor is provided in the surge tank 9, the engine 1
The temperature of the intake air introduced into the combustion chamber 1a is accurately detected. Therefore, the actuator 20 is drive-controlled based on the highly accurate intake air temperature Tin, and as a result, the accuracy in controlling the intake control valve 19 can be significantly increased.

Now, in the various control routines of FIG.
After the processing of step 100, the ECU 41 shifts the processing to step 201. The processing of steps 201 to 204 described below is for a series of “fuel injection amount control”.

In step 201, the ECU 41
The basic injection amount TBASE is calculated based on the detection signals (engine speed NE, intake pressure PiM, etc.) read this time. The basic injection amount TBASE in the present embodiment
Has already taken into consideration other operating conditions except the intake air temperature Tin described below.

In step 202, the injection amount correction coefficient FT is calculated based on the intake air temperature Tin read this time.
Calculate Hin. Here, this injection amount correction coefficient FTH
in is calculated by referring to a map as shown in FIG. 7, for example. That is, when the intake air temperature Tin is relatively low, the injection amount correction coefficient FTHin is a large value (value larger than “1.0”), and when the intake air temperature Tin is relatively high, the injection amount correction coefficient FTHin is small. It is set to a value (a value smaller than “1.0”).

Next, at step 203, the injection amount correction coefficient FTHin is added to the basic injection amount TBASE calculated this time.
A value obtained by multiplying by is set as the target injection amount TAU. Then, in the following step 204, the injector 4 is controlled based on the target injection amount TAU set this time.

In this way, Step 201 to Step 2
At 04, fuel injection amount control is executed. Here, in this injection amount control, the target injection amount TAU is calculated and set based on the intake air temperature Tin and the like.

Also in this embodiment, the intake air temperature Tin is
The fuel injection amount can be controlled on the basis of the detection result detected by the intake air temperature sensor 21 on the downstream side of the intake control valve 19 and on the upstream side of the intake valve 5. Therefore, similarly to the above, the temperature of the intake air introduced into the combustion chamber 1a of the engine 1 is accurately detected, and the intake air temperature T with high accuracy is detected.
The injector 4 is drive-controlled based on in, and as a result, the accuracy in fuel injection control can be significantly increased.

Now, in the various control routines of FIG.
After performing the process of step 204, the ECU 41 shifts the process to step 301. The processing of steps 301 to 304 described below is for a series of "ignition timing control".

In step 301, the ECU 41
The basic ignition timing ABASE is calculated based on the detection signals (engine speed NE, intake pressure PiM, etc.) read this time. The basic ignition timing ABAS in this embodiment is
Regarding E as well, other operating conditions other than the intake air temperature Tin described below have already been considered.

In step 302, the ignition timing correction term AT is calculated based on the intake air temperature Tin read this time.
Calculate Hin. Here, this ignition timing correction term ATH
in is calculated by referring to a map as shown in FIG. 8, for example. That is, when the intake air temperature Tin is relatively low, the ignition timing correction term ATHin is a large value (value larger than “0”), and when the intake air temperature Tin is relatively high, the ignition timing correction coefficient ATHin is a small value ( (Value smaller than "0").

Next, at step 303, the ignition timing correction term ATHi is added to the basic ignition timing ABASE calculated this time.
The value obtained by adding n is set as the target ignition timing AOP.
Then, in the following step 304, the igniter 14 is controlled based on the target ignition timing AOP set this time.

In this way, steps 301 to 3
At 04, ignition timing control is executed. here,
Also in this ignition timing control, the target ignition timing AOP is calculated and set according to the intake air temperature Tin and the like.

Also in this embodiment, the intake air temperature T on the downstream side of the intake control valve 19 and on the upstream side of the intake valve 5 is also increased.
The ignition timing can be controlled based on in. Therefore, similarly to the above, the temperature of the intake air introduced into the combustion chamber 1a of the engine 1 is accurately detected, and the intake air temperature T with high accuracy is detected.
The igniter 14 is controlled based on in. As a result, the accuracy in controlling the ignition timing can be significantly improved.

Now, in the various control routines of FIG.
After the processing of step 304, the ECU 41 shifts the processing to step 401. The processing from step 401 to step 404, which will be described below, is performed by a series of "EG
R control ”.

At step 401, the ECU 41
The basic EGR opening degree EGRB is calculated based on the detection signals (engine speed NE, intake pressure PiM, etc.) read this time. The basic EGR opening degree EGR in the present embodiment
Regarding B as well, the other operating conditions except the intake air temperature Tin described below have already been taken into consideration.

In step 402, the EGR opening degree correction coefficient Ein is calculated based on the intake air temperature Tin read this time. Here, this EGR opening correction coefficient E
In is also calculated by referring to a map (not shown). That is, when the intake air temperature Tin is relatively low, the EGR opening degree correction coefficient Ein has a large value.
When the intake air temperature Tin is relatively high, the EGR opening degree correction coefficient Ein is set to a small value.

Next, at step 403, the EGR opening correction coefficient Ei is added to the basic EGR opening EGRB calculated this time.
Target EGR opening (number of steps) EGR
Set as S. Then, in the following step 404, EGR is performed based on the target EGR opening degree set this time.
The valve 18 (step motor) is controlled.

In this way, steps 401 to 4
At 04, EGR control is executed. Here, also in this EGR control, the target EGR opening degree EGRS is calculated and set according to the intake air temperature Tin and the like. And E
The CU 41 once ends the subsequent processing.

Therefore, also in the EGR control, the accuracy can be remarkably improved as in the above case. As described above, in this embodiment, the intake temperature Tin on the downstream side of the intake control valve 19 is detected by the intake temperature sensor 21. And after considering the detection result,
Control of the actuator 20 (intake control valve 19), fuel injection amount control, ignition timing control, EGR control, etc. are performed. Therefore, when performing various controls, it is possible to accurately detect the temperature of the intake air introduced into the combustion chamber 1a of the engine 1. And the intake air temperature T with high accuracy
Actuator 20 (intake control valve 19) based on in
, Injector 4, igniter 14, EGR valve 1
8 and the like can be well controlled.

(Second Embodiment) Next, a second embodiment of the present invention will be described with reference to FIGS.
However, since the configuration and the like of this embodiment are almost the same as those of the above-described first embodiment, the same members and the like are designated by the same reference numerals and the description thereof will be omitted. And below,
The difference from the first embodiment will be mainly described.

In this embodiment, as shown in FIG. 10, the first
The intake air temperature sensor 21 described in the embodiment is not provided, but instead, the intake air temperature sensor 31 is provided in the surge tank 9 upstream of the intake control valve 19. The intake air temperature sensor 31 detects the upstream intake air temperature THA. In other words, the present embodiment has the same configuration as that of the conventional technique in terms of the sensor arrangement in detecting the intake air temperature. However, this embodiment is different from the prior art and the first embodiment in that the ECU 41 estimates and detects the intake air temperature Tin downstream of the intake control valve 19 using the detection result of the intake air temperature sensor 31. Are different.

The intake air temperature sensor 31 will be described below.
The processing contents for estimating the intake air temperature Tin on the downstream side of the intake control valve 19 based on the upstream intake air temperature THA detected by

FIG. 11 shows E when the engine 1 is in operation.
It is a flowchart which shows the "intake air temperature estimation routine" performed by CU41, and is performed by a regular interruption every predetermined time.

When the processing shifts to this routine, first, at step 501, the ECU 41 causes the intake air temperature sensor 3 to operate.
The detection signals (including the upstream intake air temperature THA) and the like from the sensors 22 to 31 including 1 are read.

Next, in step 502, the ECU 4
1 calculates the water temperature correction coefficient KTHW based on the cooling water temperature THW read this time. This water temperature correction coefficient KTHW
When calculating, for example, a map as shown in FIG. 12 is referred to. That is, when the cooling water temperature THW is relatively low, the intake air temperature Tin on the downstream side is equal to the intake air temperature TH on the upstream side.
From the empirical rule that it is lower than A, the water temperature correction coefficient KTHW is set to a small value (a value smaller than "1.0").

Subsequently, in step 503, the ECU
Reference numeral 41 calculates the air flow rate QA based on the engine speed NE and the intake pressure PiM that have been read this time. And
At step 504, based on the air flow rate QA,
The intake flow rate correction term KQA is calculated. When calculating the intake flow rate correction term KQA, for example, a map as shown in FIG. 13 is referred to. That is, when the air flow rate QA is large, the intake air flow rate correction term KQA is set to a small value based on the empirical rule that the intake air temperature Tin on the downstream side is low.

Next, at step 505, the ECU 4
1 calculates the injection time correction term KINJTIME based on the current fuel injection time INJTIME (however, the injection time after intake is started is converted into an angle). When calculating the injection time correction term KINJTIME,
For example, a map as shown in FIG. 14 is referred to. That is, as the fuel injection time INJTIME becomes larger on the positive side, the chance of vaporizing the fuel decreases, and the intake air temperature Tin on the downstream side does not become so low.
INJTIME is set to a value close to zero. On the other hand, from the empirical rule that the larger the fuel injection time INJTIME is on the negative side, the more the chance of vaporizing the fuel and the lower the intake air temperature Tin on the downstream side is, the injection time correction term KINJTIM
E is set to a large value on the negative side.

Further, in step 506, the ECU
Reference numeral 41 calculates an open angle correction term KTACO based on the intake control valve open angle TACO of this time (the time from the intake side top dead center until the intake control valve 19 is opened is converted into an angle). When calculating this open angle correction term KTACO,
For example, a map as shown in FIG. 15 is referred to. That is, as the intake control valve 19 is opened earlier than the intake top dead center, the amount of intake air blowback is large, and the intake air temperature Tin on the downstream side is large.
According to the empirical rule that is higher, the open angle correction term KTACO is set to a larger value. On the other hand, as the intake control valve 19 is opened later than the intake top dead center, the amount of blowback of the intake air is small and the intake air temperature Tin on the downstream side does not become so high. Therefore, the open angle correction term KTACO becomes zero. It is set to a close small value.

Next, at step 507, the ECU 4
1 calculates the closing angle correction term KTACC based on the current intake control valve closing angle TACC (the time from the intake side bottom dead center until the intake control valve 19 is closed). When calculating the closing angle correction term KTACC,
For example, a map as shown in FIG. 16 is referred to. That is, as the intake control valve 19 is closed earlier than the intake bottom dead center, so-called adiabatic expansion is increased, and the intake air temperature Tin on the downstream side is lowered.
CC is set to a large value on the negative side. On the other hand, as the intake control valve 19 is closed later than the intake bottom dead center,
From the empirical rule that the intake air temperature Tin on the downstream side becomes high, the open angle correction term KTACO is set to a small value close to zero, and is set to a larger value as the intake control valve closing angle TACC increases. It is considered that this is because the intake air accumulated in the dead volume between the intake valve 5 and the intake control valve 19 is taken in in the next cycle.

Then, in step 508, the ECU 41 considers various correction terms calculated this time on the basis of the upstream intake air temperature THA read this time, and the intake temperature T
Estimate and calculate in. That is, the upstream intake air temperature THA
In contrast, the intake flow rate correction term KQA and the water temperature correction coefficient KTH
A value obtained by adding the value obtained by multiplying W, the injection time correction term KINJTIME, the opening angle correction term KTACO, and the closing angle correction term KTACC is estimated and set as the intake air temperature Tin. Then, the subsequent processing is temporarily terminated.

In this embodiment, various controls are executed based on the intake air temperature Tin estimated and detected as described above, as in the first embodiment. As described above, in this embodiment, the intake air temperature Tin on the downstream side of the intake control valve 19 is not directly detected, but the intake air temperature THA on the upstream side of the intake control valve 19 and the like are used for the downstream operation. The intake air temperature Tin on the side is estimated and detected. Then, various controls are executed based on the intake air temperature Tin. Therefore, the same operational effects as those described in the first embodiment are obtained.

Further, in this embodiment, the intake air temperature sensor 31 for detecting the intake air temperature THA on the upstream side of the intake control valve 19 is provided. That is, the mechanical configuration for detecting the intake air temperature is the same as that of the conventional technique. Therefore, as compared with the conventional technique, no trouble is caused in the arrangement of the sensor and the cost is not increased. That is, in the present embodiment, it is possible to enjoy the merit of using the intake air temperature sensor 31 that is conventionally used as it is.

The present invention is not limited to the above embodiments,
For example, the configuration may be as follows. (1) In each of the above embodiments, based on the intake air temperature Tin,
This is embodied when the fuel injection amount control, the ignition timing control, and the EGR control are performed in addition to the control of the intake control valve 19. However, it can also be embodied when controlling at least one of these. Further, in addition to the above control, for example, the fuel injection timing control, the ISCV 11 control, and the like may be implemented.

(2) In the second embodiment, the upstream intake air temperature THA is multiplied by the intake flow rate correction term KQA and the water temperature correction coefficient KTHW, and the injection time correction term KINJTI.
ME, opening angle correction term KTACO, and closing angle correction term KTA
The value obtained by adding each CC is estimated and set as the intake air temperature Tin. However, it is not always necessary to consider all of these, or additional factors may be considered. Further, in estimating and detecting the intake air temperature Tin, it is not necessary to use the above mathematical expression, and for example, the multiplied portion may be added, or the added portion may be multiplied.

(3) In each of the above embodiments, a gasoline engine was used as the engine, but a vehicle equipped with a diesel engine can also be used. (4) In each of the above-described embodiments, the opening of the ISCV 11 is controlled by controlling the duty of the solenoid 11a. However, a stepper motor or the like may be used as an actuator to drive and control it. Further, instead of the ISCV11, the throttle valve 8
The opening and closing may be controlled by an actuator such as a step motor.

(5) The curve of the map in each of the above embodiments is not necessarily limited to the curve shown in the figure. The technical idea which is not described in the claims of the claims and can be grasped from the above-mentioned embodiment will be described below together with the effect thereof.

(A) In the intake control device for an internal combustion engine according to claim 1, the controlled object is an injector, a throttle valve, an idle speed control valve,
It is characterized by being at least one of an igniter and an EGR valve.

(B) In the intake control device for an internal combustion engine according to claim 1 or the above-mentioned supplementary note (a), the intake air temperature detecting means includes an upstream side intake valve for detecting an intake air temperature upstream of the intake control valve. Based on the temperature sensor, the detection result of the intake air temperature sensor and the detection result of the operating state detection means,
And an estimation means for estimating the intake air temperature on the downstream side of the intake control valve.

With such a structure, the intake air temperature detecting means can be structured with a mechanical structure equivalent to that of the conventional one, so that cost increase can be suppressed.

[0081]

As described in detail above, according to the present invention,
In 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, it is possible to improve the control accuracy, and thus the accuracy is improved. It has an excellent effect that it is possible to prevent the occurrence of a defect due to the decrease of

[Brief description of the drawings]

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

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

FIG. 3 is a block diagram showing an electrical configuration of the ECU of the first embodiment.

FIG. 4 is a flowchart showing “various control routines” executed by the ECU in the first embodiment.

FIG. 5 is a flowchart showing an “intake control valve control routine” executed by the ECU in the first embodiment.

FIG. 6 is a map showing the relationship between intake air temperature and closing timing.

FIG. 7 is a map showing a relationship between an intake air temperature and an injection amount correction coefficient.

FIG. 8 is a map showing a relationship of an ignition timing correction term with respect to intake air temperature.

FIG. 9 is a map showing the relationship between intake air temperature and EGR opening correction coefficient.

FIG. 10 is a schematic configuration diagram showing an engine intake control device of a second embodiment.

FIG. 11 is a flowchart showing an “intake air temperature estimation routine” executed by the ECU in the second embodiment.

FIG. 12 is a map showing a relationship between a cooling water temperature and a water temperature correction coefficient.

FIG. 13 is a map showing the relationship of the intake flow rate correction term with respect to the air flow rate.

FIG. 14 is a map showing a relationship between a fuel injection time and an intake flow rate correction term.

FIG. 15 is a map showing a relationship between an intake control valve opening angle and an opening angle correction term.

FIG. 16 is a map showing a relationship between an intake control valve closing angle and a closing angle correction term.

FIG. 17 is a timing chart showing the opening of the intake valve and the like with the passage of time in the prior art.

FIG. 18 is a graph showing the relationship between output torque and engine speed in the prior art.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Engine as an internal combustion engine, 2 ... Intake passage, 4 ... Injector constituting a controlled object, 8 ... Throttle valve capable of constituting a controlled object, 11 ... Idle speed control valve (ISCV) capable of constituting a controlled object, 14
... igniter constituting controlled object, 18 ... EGR valve constituting controlled object, 19 ... intake control valve, 20 ... actuator, 21 ... operating condition detecting means, intake temperature sensor constituting intake temperature detecting means, 22 ... operating condition Throttle sensor constituting detection means 23 ... Idle switch constituting operation state detection means 24 ... Intake pressure sensor constituting operation state detection means 25 ... Oxygen sensor constituting operation state detection means 26 ... Operation state detection A water temperature sensor that constitutes the means, 27 ... a rotation speed sensor that constitutes the operating state detecting means, 28 ... a crank angle sensor that constitutes the operating state detecting means, 29 ... a vehicle speed sensor that constitutes the operating state detecting means, 3
0 ... Neutral start switch constituting operating state detecting means, 31 ... Upstream intake air temperature sensor, 41 ... ECU constituting intake control means, controlled object control means and control content adjusting means.

Claims (1)

[Claims] 1. A throttle valve provided in the middle of an intake passage of an internal combustion engine, an intake control valve provided in an intake passage corresponding to each cylinder of the internal combustion engine on the downstream side of the throttle valve, An actuator for opening and closing a control valve, an operating state detecting means for detecting an operating state of the internal combustion engine, an intake control means for controlling the actuator based on a detection result of the operating state detecting means, and the operating state detecting means An intake air control apparatus for an internal combustion engine, comprising: a control target control means for controlling another control target of the internal combustion engine based on a detection result of the intake air temperature for detecting an intake air temperature downstream of the intake control valve. Detection means, and based on the detection result of the intake air temperature detection means, at least one control by the intake control means and the controlled object control means An intake air control device for an internal combustion engine, comprising: a control content adjusting means for adjusting the volume.