JPH07286562A - Intake air temperature and egr control device of internal combustion engine - Google Patents

Abstract

PURPOSE:To attain improvement of fuel consumption, reduction of emission, avoidance of knocking, or improvement of output desired in every operation territory of an internal combustion engine. CONSTITUTION:Based on the operating condition of an internal combustion engine 1, the target opening SINV of an intake passage valve 5 is computed by an ECU 20, corresponding to the temperature of intake air after passing and mixing through an intake air heating passage 13a arranged with a heat exchanger 7 heating intake air and an intake air cooling passage 13b arranged with a heat exchanger 8 cooling intake air, and hence the intake passage valve 5 is controlled. In addition, the target opening SEGR of an EGR valve 4 is computed by the ECU 20 based on the operating condition of the engine l, and hence the EGR valve 4 is controlled. Hereby, the intake air temperature and the EGR quantity are independently properly controlled based on the operating condition of the engine 1, and hence improvement of fuel consumption, decrease of emission, avoidance of knocking, or improvement of output desired in every operation territory can be attained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an internal combustion engine (engine).
The present invention relates to an intake air temperature and EGR (Exhaust Gas Recirculation) control device for improving fuel efficiency, reducing nitrogen oxides (NOx) in exhaust gas, avoiding knocking, or improving output in accordance with the operating state of.

[0002]

2. Description of the Related Art Conventionally, as a prior art document related to an intake air temperature of an internal combustion engine and an EGR control device, there has been disclosed in Japanese Utility Model Publication No. 57-
The ones disclosed in JP-A-101359 and JP-A-58-150022 are known.

The former one discloses a technique for improving the thermal efficiency of the engine by correcting the intake air temperature of the fuel system while the internal combustion engine is warming up. In the latter, there is disclosed a technique for forcibly lowering the intake air temperature by using cooling water to improve the intake charging efficiency.

[0004]

By the way, although the intake temperature is corrected to improve the fuel consumption during actual driving in the former case, and to improve the output of the engine in the latter case, the purpose of engine operation differs from each other. Since the area is limited, the effect in the practical range may be diminished.

Therefore, the present invention provides an intake air temperature and EGR control device for an internal combustion engine capable of achieving various objects such as desired improvement of fuel consumption, reduction of emissions, avoidance of knocking or improvement of output for each operating region of the internal combustion engine. Is an issue.

[0006]

According to a first aspect of the present invention, there is provided an intake air temperature and EGR control device for an internal combustion engine, wherein an EGR gas, which is a part of exhaust gas taken out from an exhaust system of the internal combustion engine, is introduced into the intake system of the internal combustion engine. An EGR valve to be introduced, an intake passage valve for setting a passage ratio of intake air passing through two passages formed of an intake air heating passage and an intake cooling passage formed in the intake passage of the internal combustion engine, and the intake air Intake air heating means disposed on the heating passage side for heating the intake air, intake air cooling means disposed on the intake cooling passage side for cooling the intake air, and the intake passage valve for controlling the intake air heating passage Intake passage valve control means for adjusting the temperature of the intake air mixed after passing through the intake air cooling passage and the EGR valve opening degree for calculating the EGR valve opening degree of the EGR valve based on the operating state of the internal combustion engine. Performance Means, in which includes an EGR valve control means for controlling said EGR valve in response to the EGR valve opening degree calculated by the EGR valve opening degree calculating means.

An intake air temperature and EGR control device for an internal combustion engine according to a second aspect includes an EGR valve for introducing an EGR gas, which is a part of exhaust gas taken out from an exhaust system of the internal combustion engine, into the intake system of the internal combustion engine, An intake passage valve that sets a passage ratio of intake air that passes through two passages that are formed in the intake passage of the intake system of the internal combustion engine and that are formed of an intake heating passage and an intake cooling passage, and the intake passage valve is disposed on the intake heating passage side. The intake air heating means for heating the intake air, the intake cooling means arranged on the intake cooling passage side for cooling the intake air, the intake heating passage and the intake cooling passage based on the operating state of the internal combustion engine. And an intake passage valve opening calculation means for calculating an intake passage valve opening degree of the intake passage valve corresponding to the intake air temperature after being mixed by passing through Intake And an intake manifold valve control means for controlling said intake passage valve according to way valve opening degree, E for calculating the EGR valve opening degree of the EGR valve based on the operating state of the internal combustion engine
It is provided with a GR valve opening calculation means and an EGR valve control means for controlling the EGR valve in accordance with the EGR valve opening calculated by the EGR valve opening calculation means.

An intake air temperature and EGR control device for an internal combustion engine according to a third aspect of the present invention includes an EGR valve for introducing EGR gas, which is a part of exhaust gas taken out from an exhaust system of the internal combustion engine, into the intake system of the internal combustion engine, An intake passage valve that sets a passage ratio of intake air that passes through two passages that are formed in the intake passage of the intake system of the internal combustion engine and that are formed of an intake heating passage and an intake cooling passage, and the intake passage valve is disposed on the intake heating passage side. The intake air heating means for heating the intake air, the intake cooling means arranged on the intake cooling passage side for cooling the intake air, and the intake heating passage and the intake cooling passage are mixed after passing through the intake heating passage and the intake cooling passage. An intake air temperature sensor that detects an intake air temperature, an intake passage valve feedback control unit that feedback-controls the intake passage valve according to the output of the intake air temperature sensor, and an operating state of the internal combustion engine. An EGR valve opening degree calculating means for calculating an EGR valve opening degree of the EGR valve Zui, wherein E in response to the EGR valve opening degree calculated by the EGR valve opening degree calculating means
And an EGR valve control means for controlling the GR valve.

An intake air temperature and EGR control device for an internal combustion engine according to a fourth aspect of the invention includes an EGR valve for introducing EGR gas, which is a part of exhaust gas taken out from an exhaust system of the internal combustion engine, into the intake system of the internal combustion engine. An intake passage valve that sets a passage ratio of intake air that passes through two passages that are formed in the intake passage of the intake system of the internal combustion engine and that are formed of an intake heating passage and an intake cooling passage, and the intake passage valve is disposed on the intake heating passage side. An intake air heating means for heating the intake air, an intake air cooling means disposed on the intake air cooling passage side for cooling the intake air, a knock sensor for detecting occurrence of knocking of the internal combustion engine, and an output of the knock sensor. In response to the output of the knock sensor, the intake passage valve feedback control means for feedback-controlling the intake passage valve in a direction to avoid knocking in accordance with Those comprising an EGR valve feedback control means for feedback controlling the EGR valve in the direction of.

[0010]

According to the first aspect of the present invention, the intake passage valve is controlled by the intake passage valve control means, the intake heating passage for heating the intake air is provided, and the intake cooling means for cooling the intake air is provided. The intake air temperature is adjusted after passing through the intake air cooling passage. In addition, the EGR valve opening calculation means determines the EG of the EGR valve based on the operating state of the internal combustion engine.
The R valve opening degree is calculated, and the EGR valve opening degree is calculated according to the EGR valve opening degree.
The EGR valve is controlled by the valve control means. In this way, the intake air temperature and the EGR amount are independently and appropriately controlled.

According to another aspect of the present invention, the intake air passage is provided with an intake air heating means for heating the intake air based on the operating condition of the internal combustion engine by the intake passage valve opening calculation means, and the intake cooling means for cooling the intake air. The intake passage valve opening degree of the intake passage valve corresponding to the intake air temperature after being mixed by passing through the intake cooling passage in which is arranged is calculated, and the intake passage valve control means is calculated according to the intake passage valve opening degree. The intake passage valve is controlled by.
The EGR valve opening calculation means calculates the EGR valve opening of the EGR valve based on the operating state of the internal combustion engine.
The EGR valve is controlled by the EGR valve control means according to the valve opening degree. In this way, the intake air temperature and the EGR amount are independently and appropriately controlled based on the operating state of the internal combustion engine.

According to another aspect of the present invention, there are provided an intake air heating passage for arranging an intake air heating means for heating the intake air by the intake passage valve feedback control means, and an intake cooling passage for arranging an intake cooling means for cooling the intake air. The intake passage valve is feedback-controlled in accordance with the output of the intake air temperature sensor that detects the intake air temperature that is mixed after passing through. The EGR valve opening calculation means calculates the EGR valve opening of the EGR valve based on the operating state of the internal combustion engine, and the EGR valve control means controls the EGR valve according to the EGR valve opening. In this way, the intake air temperature and the EGR amount are independently and appropriately controlled.

According to another aspect of the present invention, there are provided two intake air passages including an intake air heating passage for arranging an intake air heating means for heating the intake air by an intake passage valve and an intake air cooling passage for arranging an intake cooling means for cooling the intake air. The passage ratio of the intake air passing through the passage is set. Then, the intake passage valve feedback control unit feedback-controls the intake passage valve in the direction in which knocking is avoided in accordance with the output of the knock sensor that detects the occurrence of knocking of the internal combustion engine. Further, the EGR valve feedback control means feedback-controls the EGR valve in the direction in which knocking is avoided according to the output of the knock sensor. In this way, the intake air temperature and the EGR amount are independently feedback-controlled as appropriate.

[0014]

EXAMPLES The present invention will be described below based on specific examples.

<First Embodiment> FIG. 1 is a schematic diagram showing a mechanical structure of an intake air temperature and EGR control device of an internal combustion engine according to a first embodiment of the present invention, and FIG. 2 is a first embodiment of the present invention. FIG. 3 is a block diagram showing an intake air temperature of the internal combustion engine and an electrical configuration of an EGR control device.

In FIG. 1, 1 is an internal combustion engine (engine), 2 is an engine speed N in synchronization with the rotation angle of the internal combustion engine 1.
A rotation angle sensor for outputting an E signal, 3 is an intake pressure sensor for measuring an intake pipe negative pressure in the intake pipe 13 of the internal combustion engine 1 and outputting an intake pipe pressure PM signal, and 4 is a part of exhaust gas E
An electronic type (electrically opened and closed by an actuator including a stepping motor or the like) EGR valve 5 for recirculating the GR gas into the intake pipe 13 is an intake air heating passage 13a formed in the intake pipe 13 along the intake passage. And intake cooling passage 13b
An intake passage valve for setting the passage ratio of the intake air passing through the two passages, and 6 is a stepping motor for electrically driving the intake passage valve 5 to change the passage ratio of the intake air passing through the two passages. It is a passage switching actuator including

Further, 7 is a heat exchanger for circulating a high-temperature medium (for example, cooling water of the internal combustion engine 1) to raise the intake air temperature in the intake air heating passage 13a, and 8 is intake air in the intake air cooling passage 13b. A heat exchanger for circulating a low-temperature medium (for example, a refrigerant of an air conditioner) to lower the temperature, 9
Is a water temperature sensor that measures the cooling water temperature of the internal combustion engine 1 and outputs a cooling water temperature THW signal, 10 is an intake air temperature sensor that detects the intake air temperature of the internal combustion engine 1 and outputs an intake air temperature THA signal, and 11 is the EGR valve 4 Is connected to the
GR valve opening degree EGR valve opening degree sensor which outputs a PEGRV signal, 12 is an intake passage valve opening degree sensor which is connected to the intake passage valve 5 and detects the opening degree and outputs an intake passage valve opening degree PINV signal.

Further, 20 receives the respective signals from the rotation angle sensor 2, the intake pressure sensor 3, the water temperature sensor 9, the intake temperature sensor 10, the EGR valve opening degree sensor 11 and the intake passage valve opening degree sensor 12, and the internal combustion engine The ECU (Electronic Co) that outputs the SINV signal to the passage switching actuator 6 and the SEGR signal to the EGR valve 4 based on the determination of the operating state of No. 1
ntrol Unit: electronic control unit). As described below,
The SINV signal from the ECU 20 controls the intake passage valve 5 via the passage switching actuator 6 to control the intake heating passage 13a.
And a ratio of intake air passing through the intake air cooling passage 13b is set to a desired intake air temperature, and the SEGR signal controls the EGR valve opening of the EGR valve 4 to lower the combustion temperature of the internal combustion engine 1 and exhaust gas. Nitrogen oxide (NOx) in gas is reduced (emission is reduced).

As shown in FIG. 2, the ECU 20 mainly comprises a CPU (central processing unit) 21, a ROM 22 storing a control program, a RAM 23 storing various data,
It comprises an A / D converter 24, an EGR valve 4, and an output circuit 25 for driving the intake passage valve 5. Rotation angle sensor 2, intake pressure sensor 3, water temperature sensor 9, intake air temperature sensor 10, EG
Of the signals from the R valve opening sensor 11 and the intake passage valve opening sensor 12, the engine speed NE from the rotation angle sensor 2
Is a digital input, it is taken into the CPU 21 as it is. Intake pipe pressure PM from the remaining intake pressure sensor 3,
Cooling water temperature THW from the water temperature sensor 9, intake air temperature sensor 10
Intake air temperature THA, EGR valve opening degree sensor 11 from EGR valve opening degree PEGRV, and intake passage valve opening degree sensor 12
Since the intake passage valve opening degree PINV from is an analog input, it is converted into a digital signal via the A / D converter 24 and then taken into the CPU 21.

With such a configuration, the EGR valve 4 is driven by the SEGR signal from the output circuit 25 of the ECU 20, and the EGR valve opening sensor 1 connected to the EGR valve 4 is driven.
The EGR valve opening degree PEGRV signal from 1 is A of the ECU 20.
It is fed back to the output circuit 25 via the / D converter 24 and the CPU 21, and closed loop control is performed.
Further, the intake passage valve 5 is driven by the SINV signal from the output circuit 25 of the ECU 20, and the intake passage valve opening degree P from the intake passage valve opening degree sensor 12 connected to the intake passage valve 5 is increased.
The INV signal is the A / D converter 24 of the ECU 20, the CPU 2
Is fed back to the output circuit 25 via 1.
Similar closed loop control is implemented.

Next, each control will be described based on a flow chart showing a processing procedure of the CPU 21 used in the intake air temperature and EGR control device of the internal combustion engine according to the present embodiment.

<< Base Routine of Intake Temperature and EGR Control: See FIG. 3 >> FIG. 3 is a base routine of the intake temperature and EGR control.

At the same time when the power is turned on (when the power is turned on), first,
Initialization is executed in step S100, and step S20
0, the EGR valve opening calculation subroutine is executed, and EGR
The optimum target EGR valve opening degree SEGR is calculated based on the operating state of the internal combustion engine to be controlled by the valve 4. Next, the routine proceeds to the subroutine for calculating the intake passage valve opening degree in step S300, and the optimum target intake passage valve opening degree SINV based on the operating state of the internal combustion engine to be controlled by the intake passage valve 5 is calculated.
Next, the process proceeds to the subroutine for driving the intake passage valve in step S400, and the intake passage valve 5 is drive-controlled so as to reach the target intake passage valve opening SINV calculated in step S300. Then, the process proceeds to the EGR valve drive subroutine of step S500, and the EGR valve 4 is drive-controlled so that the target EGR valve opening degree SEGR calculated in step S200 is achieved.

Next, the specific procedure of each subroutine constituting the base routine of FIG. 3 will be described in detail below.

<EGR valve opening calculation subroutine: FIG. 4
Reference> FIG. 4 is a subroutine for calculating the EGR valve opening degree which achieves the EGR valve opening degree calculating means.

After the engine speed NE is read in step S201 and the intake pipe pressure PM is read in step S202, the process proceeds to step S203, and the basic EGR valve opening degree SEGRB is calculated. Here, the basic EGR valve opening degree SEGRB is
It is calculated on the basis of a two-dimensional map in which the engine speed NE and the intake pipe pressure PM are parameters as shown in FIG. 5, which is obtained by an experiment in advance for the internal combustion engine 1 in the cooling water temperature THW = 80 ° C. That is, the basic EGR valve opening degree SEGRB corresponding to the predetermined engine speed NE (rpm) and the predetermined intake pipe pressure PM (mmHg) becomes α. This basic EGR valve opening degree SEGR
B is the EGR valve opening degree corresponding to the optimum EGR amount in the standard operating state of the internal combustion engine, and the determining factors of the optimum EGR amount are shown in FIGS. 6 and 7, and the region corresponding to the operating state of the internal combustion engine The optimum EGR amount is set for each. Here, the areas 1 to 4 in FIG. 7 correspond to the areas No. 1 to No. 4 in FIG. 6, respectively.

6 and 7, in the emission priority area (area) of No. 1, the urban traveling area (0 to 5)
0 km / h), and EGR in the area that is commonly used in daily life.
A large amount is used to reduce the amount of nitrogen oxides (NOx) and the intake air temperature THA is lowered to avoid knocking accompanying the rise in intake air temperature due to the introduction of EGR gas. The relationship between the EGR amount and the intake air temperature THA at this time is a characteristic that the intake air temperature THA increases in proportion to the EGR amount, as shown in FIG. Next, in the fuel economy priority region (region of No. 2), the vehicle speed is in the medium load region from medium speed to high speed, which is relatively stable and has little acceleration / deceleration (50 to 100 km / h)
Is about), the intake air temperature THA is increased, and EG
With a large amount of R, intake expansion and pumping loss due to a large amount of EGR can be reduced, and fuel efficiency can be reduced by increasing thermal efficiency. The relationship between the intake air temperature THA and the air expansion coefficient at this time is, as shown in FIG. 9, that the air expansion coefficient is 1.0 when the intake air temperature THA is 25 ° C., and the air expansion is proportional to the intake air temperature THA. It is a characteristic that the coefficient becomes large. Next, in the No. 3 power priority region and the knock region (the regions thereof), the EGR amount is set to a small amount to stabilize the combustion and lower the intake air temperature THA to improve knocking avoidance and intake air charging efficiency. In the normal region of No. 4, the normal control similar to the conventional control is executed, and the EGR amount and the intake air temperature THA are in a medium range.

Next, in step S204, the cooling water temperature THW is read, and then in step S205, the water temperature correction value FTHWEGR is calculated. here,
The water temperature correction value FTHWEGR is calculated based on a map corresponding to the cooling water temperature THW as shown in FIG. That is, the cooling water temperature THW is 70 ° C.
The lower the water temperature correction value FTHWEGR is made to be less than 1.0, the combustion is stabilized during warming up, and the cooling water temperature T
When the HW is higher than 90 ° C., the water temperature correction value FTHWEGR is set to be smaller than 1.0 in order to avoid knocking.
The intake air temperature due to R gas is lowered. Then, the process proceeds to step S206, the final target EGR valve opening degree SEGR is calculated, and the present subroutine ends. Where goal E
The GR valve opening degree SEGR is obtained by multiplying the basic EGR valve opening degree SEGRB calculated in step S203 by the water temperature correction value FTHWEGR calculated in step S205.
It becomes an actuator control signal for the GR valve 4. The relationship between the target EGR valve opening degree SEGR and the EGR amount at this time is such a characteristic that the EGR amount increases in proportion to the target EGR valve opening degree SEGR, as shown in FIG.

<Subroutine for calculating intake passage valve opening: see FIG. 12> FIG. 12 is a subroutine for calculating the intake passage valve opening, which serves as an intake passage valve opening calculating means.

After the engine speed NE is read in step S301 and the intake pipe pressure PM is read in step S302, the process proceeds to step S303, and the basic intake passage valve opening SINVB is opened.
Is calculated. Here, the basic intake passage valve opening SINVB
Is the engine speed NE as shown in FIG. 13, which is obtained by an experiment in advance for the internal combustion engine 1 with the intake air temperature THA = 25 ° C.
And the intake pipe pressure PM as a parameter based on a two-dimensional map. That is, the predetermined engine speed NE (rp
m) and the predetermined intake pipe pressure PM (mmHg), the basic intake passage valve opening SINVB becomes β. This basic intake passage valve opening SINVB is the intake passage valve opening corresponding to the optimum intake temperature in the standard operating state of the internal combustion engine, and the determining factors of the optimum intake temperature are the same as those described above in FIGS. 6 and 7. Shown,
The optimum intake air temperature is set for each region corresponding to the operating state of the internal combustion engine.

Next, in step S304, the intake air temperature THA is read, and then in step S305, the intake air temperature correction value FTHAINV is calculated. Here, the intake air temperature correction value FTHAINV is calculated based on a map corresponding to the intake air temperature THA as shown in FIG. That is, the intake air temperature THA
Is lower than 20 ° C, the intake air temperature correction value FTHAINV is set to 1.0 in order to correct the intake air temperature of the fuel system as in the conventional case.
When the intake air temperature THA is higher than 40 ° C., the intake air temperature correction value FTHAINV is set to 1.0 to correct the intake air temperature of the fuel system and prevent knocking.
It is made smaller to lower the intake air temperature. Then, the process proceeds to step S306, and the final target intake passage valve opening SIN
V is calculated, and this subroutine is finished. Here, the target intake passage valve opening SINV is the same as the basic intake passage valve opening SINVB calculated in step S303 and step S30.
It is obtained by the product of the intake air temperature correction value FTHAINV calculated in 5, and becomes the actuator control signal of the intake passage valve 5. The relationship between the target intake passage valve opening SINV and the intake temperature at this time is such that the intake temperature rises in proportion to the target intake passage valve opening SINV, as shown in FIG.

<Subroutine for driving intake passage valve: FIG. 16
Reference> FIG. 16 is a subroutine for driving the intake passage valve that achieves the intake passage valve control means.

After the counter C2MS is incremented in step S401, the process proceeds to step S402, and it is determined whether the counter C2MS is 2 ms or more. When the expression in step S402 is not satisfied,
No processing is performed and this subroutine is terminated. on the other hand,
When the expression in step S402 is satisfied, the process moves to step S403 and the counter C2MS is cleared to 0. In these steps S401, S402 and S403, a 2 ms cycle is created. Next, the process proceeds to step S404, and at this time, the current intake passage valve opening PINV detected by the intake passage valve opening sensor 12 connected to the intake passage valve 5 is read, and then the process proceeds to step S405. , The intake passage valve opening PINV is shown in FIG.
It is determined whether or not it is equal to or larger than the target intake passage valve opening SINV calculated in 2. The inequality sign in step S405 is not satisfied, and the current intake passage valve opening PINV is the target intake passage valve opening S.
If it has not reached INV, the routine proceeds to step S406, where the intake passage valve 5 is opened to 1 LSB (Least Significant B
It: The minimum unit) is processed.

On the other hand, when the inequality sign in step S405 is satisfied and the current intake passage valve opening PINV reaches the target intake passage valve opening SINV, the routine proceeds to step S407, where the intake passage valve opening PINV is set to the target. Intake passage valve opening SI
It is determined whether it is equal to NV. If the equal sign in step S407 is not satisfied and the current intake passage valve opening PINV exceeds the target intake passage valve opening SINV, step S4
08, the intake passage valve 5 is driven to the closing side by 1 LSB. Further, when the equal sign of step S407 is established and the current intake passage valve opening PINV is the target intake passage valve opening S.
If equal to INV, the process proceeds to step S409, and the current intake passage valve opening PINV is held. Then, after the processing of step S406, step S408 and step S409, this subroutine is ended.

<EGR Valve Driving Subroutine: See FIG. 17> FIG. 17 is an EGR valve driving subroutine for achieving the EGR valve control means.

In step S501, it is determined whether the counter C2MS has been cleared to 0. Step S50
When the equal sign of 1 is not established, no processing is performed and the present subroutine ends. On the other hand, when the equal sign in step S501 is established, the process proceeds to step S502, at which point the EGR valve opening sensor 1 connected to the EGR valve 4 is connected.
After the current EGR valve opening degree PEGRV detected in 1 is read, the process proceeds to step S503, and this EGR valve opening degree PEGRV is the target EGR valve opening degree SE calculated in FIG.
It is determined whether it is equal to or higher than GR. The inequality sign in step S503 is not established, and the current EGR valve opening degree PEGRV is set to the target E.
If the GR valve opening degree SEGR is not reached, step S
The process proceeds to 504, and the EGR valve 4 is driven to the open side by 1 LSB.

On the other hand, when the inequality sign in step S503 is established and the current EGR valve opening degree PEGRV is the target EGR valve opening degree S.
If the EGR is reached, the process proceeds to step S505,
It is determined whether the EGR valve opening degree PEGRV is equal to the target EGR valve opening degree SEGR. When the equal sign in step S505 is not satisfied and the current EGR valve opening degree PEGRV exceeds the target EGR valve opening degree SEGR, the process proceeds to step S506, and the EGR valve 4 is driven toward the closing side by 1 LSB. Also, when the equal sign in step S505 is established, the current E
If the GR valve opening degree PEGRV is equal to the target EGR valve opening degree SEGR, the routine proceeds to step S507, where the current EGR
The valve opening degree PEGRV is held. Step S50
After the processing of 4, step S506 and step S507, the present subroutine is ended.

As described above, the intake air temperature and EGR control device for the internal combustion engine of the first embodiment of the present invention uses the EGR gas, which is a part of the exhaust gas extracted from the exhaust system of the internal combustion engine 1, as the intake air of the internal combustion engine 1. EGR valve 4 introduced into the system, and an intake air heating passage 13a formed in the intake passage of the intake system of the internal combustion engine 1.
And an intake passage valve 5 that sets the passage ratio of the intake air passing through the two passages including the intake cooling passage 13b and the heat exchanger 7 that is disposed on the intake heating passage 13a side and heats the intake air. Intake air heating means and intake air cooling passage 13
The intake air cooling means, which is disposed on the b side and is achieved by the heat exchanger 8 that cools the intake air, and the intake air heating passage 13a and the intake air cooling passage 13b are mixed based on the operating state of the internal combustion engine 1. Intake passage valve 5 corresponding to the intake air temperature after
Of the target intake passage valve opening SINV calculated by the ECU 20, and the target intake passage valve opening SIN calculated by the intake passage valve opening calculation means
Achieved by the intake passage valve control means that is achieved by the ECU 20 that controls the intake passage valve 5 according to V, and by the ECU 20 that calculates the target EGR valve opening degree SEGR of the EGR valve 4 based on the operating state of the internal combustion engine 1. EGR valve opening calculation means and target EGR calculated by the EGR valve opening calculation means
ECU 2 for controlling EGR valve 4 according to valve opening degree SEGR
EGR valve control means achieved at 0 is provided, and this can be the embodiment of claim 2.

Therefore, the intake air heating means achieved by the heat exchanger 7 that heats the intake air based on the operating state of the internal combustion engine 1 by the intake passage valve opening calculation means achieved by the ECU 20 is provided. The intake passage valve 5 corresponding to the intake air temperature after being mixed by passing through the intake air heating passage 13a and the intake air cooling passage 13b in which the intake air cooling means achieved by the heat exchanger 8 for cooling the intake air is arranged. Of the target intake passage valve opening SINV of
In response to the above, the intake passage valve 5 is controlled by the intake passage valve control means achieved by the ECU 20. Further, the target EGR valve opening degree SEGR of the EGR valve 4 is calculated by the EGR valve opening degree calculation means achieved by the ECU 20 based on the operating state of the internal combustion engine 1, and the EC according to the target EGR valve opening degree SEGR.
EGR valve 4 is achieved by the EGR valve control means achieved in U20.
Is controlled.

Therefore, in the internal combustion engine using the apparatus of the present embodiment, the intake air temperature and the EGR amount are controlled independently and appropriately based on the operating state thereof, so that desired fuel consumption improvement and emission reduction can be achieved for each operating region. , Knocking avoidance or power improvement is achieved.

By the way, in the above embodiment, as shown in FIG. 12, the target intake passage valve opening SINV for controlling the intake passage valve 5 based on the operating state of the internal combustion engine based on the engine speed NE and the intake pipe pressure PM is set. Although calculated, the intake passage valve 5 can be controlled without limiting to the operating state of the internal combustion engine to adjust the intake air temperature mixed after passing through the intake heating passage 13a and the intake cooling passage 13b. .

Intake air temperature and EGR of such an internal combustion engine
The control device is formed on an EGR valve 4 that introduces an EGR gas, which is a part of the exhaust gas extracted from the exhaust system of the internal combustion engine 1, into the intake system of the internal combustion engine 1, and an intake passage of the intake system of the internal combustion engine 1. Intake heating passage 13a and intake cooling passage 13b
An intake passage valve 5 for setting the passage ratio of the intake air passing through the two passages including the intake air heating means and an intake air heating means arranged in the intake air heating passageway 13a for heating the intake air. The intake cooling means, which is arranged on the intake cooling passage 13b side and is achieved by the heat exchanger 8 for cooling the intake air, and the intake passage valve 5 are controlled to pass through the intake heating passage 13a and the intake cooling passage 13b. After that, it is achieved by the intake passage valve control means achieved by the ECU 20 that adjusts the intake air temperature to be mixed, and the ECU 20 that calculates the target EGR valve opening degree SEGR of the EGR valve 4 based on the operating state of the internal combustion engine 1. EGR valve opening calculating means and E according to the target EGR valve opening SEGR calculated by the EGR valve opening calculating means.
EGR valve control means that is achieved by the ECU 20 that controls the GR valve 4 is provided, and this can be the embodiment of claim 1.

Therefore, the intake passage valve 5 is controlled by the intake passage valve control means achieved by the ECU 20, and the intake heating passage provided with the intake heating means achieved by the heat exchanger 7 for heating the intake air is arranged. The intake air temperature mixed after passing through 13a and the intake air cooling passage 13b in which the intake air cooling means achieved by the heat exchanger 8 for cooling the intake air is arranged is adjusted. Further, the EGR valve opening degree calculation means achieved by the ECU 20 is used to calculate the EGR based on the operating state of the internal combustion engine 1.
A target EGR valve opening degree SEGR of the valve 4 is calculated, and the EGR valve control means achieved by the ECU 20 controls the EGR valve 4 according to the target EGR valve opening degree SEGR.

Therefore, in the internal combustion engine using the device of the present embodiment, the intake air temperature and the EGR amount are independently controlled as appropriate, so that desired fuel efficiency improvement, emission reduction, knocking avoidance or output can be achieved for each operating region. Improvements are achieved.

Further, in the above-described embodiment, as shown in FIG. 6, a knock region of No. 3 (region shown in FIG. 7) is provided in advance, and in this knock region, the amount of EGR is small as a direction for avoiding knocking, Although the temperature THA is lowered and the predictive control is performed, a knock sensor is provided in the cylinder block of the internal combustion engine 1 so that the intake air temperature is lowered only when knocking occurrence is detected based on the knock sensor output. 2 consisting of 13a and intake air cooling passage 13b
Feedback control of the open / close position of the intake passage valve 5 for setting the passage ratio of the intake air passing through the two passages, and E
The EGR valve 4 may be feedback-controlled to the closing side so that the GR amount becomes small.

Intake air temperature and EGR of such an internal combustion engine
The control device is formed on an EGR valve 4 that introduces an EGR gas, which is a part of the exhaust gas extracted from the exhaust system of the internal combustion engine 1, into the intake system of the internal combustion engine 1, and an intake passage of the intake system of the internal combustion engine 1. Intake heating passage 13a and intake cooling passage 13b
An intake passage valve 5 for setting the passage ratio of the intake air passing through the two passages including the intake air heating means and an intake air heating means arranged in the intake air heating passageway 13a for heating the intake air. In accordance with the output of the knock sensor, which is arranged on the intake cooling passage 13b side and which is achieved by the heat exchanger 8 for cooling the intake air, a knock sensor for detecting occurrence of knocking of the internal combustion engine 1, and the output of the knock sensor. EC for feedback control of the intake passage valve 5 in a direction to avoid knocking
Intake passage valve feedback control means achieved in U20, and ECU that feedback-controls the EGR valve 4 in a direction to avoid knocking according to the output of the knock sensor.
20 is provided with EGR valve feedback control means, which can be the embodiment of claim 4.

Therefore, it is achieved by the intake air heating passage 13a in which the intake air heating means, which is achieved by the heat exchanger 7 for heating the intake air by the intake passage valve 5, is arranged, and the heat exchanger 8 for cooling the intake air. The passing ratio of the intake air passing through the two passages including the intake cooling passage 13b in which the intake cooling means is disposed is set. Then, the intake passage valve 5 is feedback-controlled in a direction to avoid knocking in accordance with the output of the knock sensor that detects the occurrence of knocking of the internal combustion engine 1 by the intake passage valve feedback control means achieved by the ECU 20. In addition, the EGR valve feedback control means achieved by the ECU 20 feedback-controls the EGR valve 4 in a direction in which knocking is avoided according to the output of the knock sensor.

Therefore, in the internal combustion engine using the device of the present embodiment, the desired intake air temperature and the EGR amount are independently feedback-controlled, and the desired knocking avoidance is achieved for each operating region.

<Second Embodiment> FIG. 18 is a schematic view showing an intake air temperature of an internal combustion engine and a mechanical structure of an EGR control device according to a second embodiment of the present invention. The intake pipe shown in FIG. The internal combustion engine 1, the ECU 20, and various signals downstream of 13 are omitted. Further, the intake air temperature of the internal combustion engine and the electrical configuration of the EGR control device according to the second embodiment of the present invention are shown in FIG.
Is similar to the block diagram of FIG. It should be noted that the same reference numerals and symbols are given to those having the same configurations or corresponding portions as those of the above-described first embodiment, and detailed description thereof will be omitted.
Further, the intake air temperature and EGR of the internal combustion engine according to the present embodiment
The flowchart showing the processing procedure of the CPU 21 used in the control device is the base routine of the intake temperature and EGR control of FIG. 3, the subroutine of the EGR valve opening calculation of FIG. 4 and the EGR valve of FIG. Since the driving subroutine is the same, the description thereof will be omitted.

In the first embodiment described above, the intake air temperature sensor 10
Is disposed on the most upstream side of the intake pipe 13, and the intake temperature is corrected in advance so that the intake passage valve 5 becomes the basic intake passage valve opening when the intake temperature THA is 25 ° C. in the standard operating state of the engine.
On the other hand, in this embodiment, the intake air temperature sensor 10 is connected to the intake air heating passage 13a and the intake air cooling passage 13b in the intake pipe 13.
Is arranged on the downstream side of the confluence point.

The subroutine for calculating the intake passage valve opening degree at this time is step S as shown in FIG. 19 instead of FIG.
After the engine speed NE is read at 311 and the intake pipe pressure PM is read at step S312, the process proceeds to step S313.
The target intake air temperature TTHA is calculated. Here, the target intake air temperature TTHA is calculated based on a two-dimensional map obtained by experiments in advance and shown in FIG. 20, which uses the engine speed NE and the intake pipe pressure PM as parameters. That is, a predetermined engine speed NE (rpm) and a predetermined intake pipe pressure PM (mmH
The target intake air temperature TTHA corresponding to g) becomes γ.

The subroutine for driving the intake passage valve is
As shown in FIG. 21 instead of FIG. 16, step S411
Then, after the counter C2MS is incremented, the process proceeds to step S412, and it is determined whether the counter C2MS is 2 ms or more. If the expression in step S412 does not hold, no processing is performed and the present subroutine ends. On the other hand, when the expression in step S412 is satisfied, the process proceeds to step S413 and the counter C
2MS is cleared to 0. These steps S41
1, 2ms in step S412 and step S413
A cycle is created. Next, in step S414, the current intake air temperature THA detected by the intake air temperature sensor 10 is read, and then in step S415, this intake air temperature THA is equal to or higher than the target intake air temperature TTHA calculated in FIG. Is determined. The inequality sign of step S415 is not established and the current intake air temperature THA is the target intake air temperature TTHA.
If not, the process proceeds to step S416, and the intake passage valve 5 is driven to the open side by 1 LSB.

On the other hand, when the inequality sign of step S415 is established and the current intake air temperature THA has reached the target intake air temperature TTHA, the routine proceeds to step S417, where the intake air temperature TH
It is determined whether A is equal to the target intake air temperature TTHA. Current intake air temperature THA is not satisfied in step S417.
Is above the target intake air temperature TTHA, the routine proceeds to step S418, where the intake passage valve 5 is driven to the closing side by 1 LSB. When the equal sign in step S417 is satisfied and the current intake air temperature THA is equal to the target intake air temperature TTHA, the process proceeds to step S419, and the current intake passage valve opening PINV is held. Then, after the processing of step S416, step S418, and step S419, this subroutine is ended. That is, the intake passage valve 5 is feedback-controlled so that the current intake air temperature THA becomes the target intake air temperature THHA.

As described above, in the intake air temperature and EGR control device for the internal combustion engine of the second embodiment of the present invention, the EGR gas which is a part of the exhaust gas taken out from the exhaust system of the internal combustion engine 1 is taken into the intake air of the internal combustion engine 1. EGR valve 4 introduced into the system, and an intake air heating passage 13a formed in the intake passage of the intake system of the internal combustion engine 1.
And an intake passage valve 5 that sets the passage ratio of the intake air passing through the two passages including the intake cooling passage 13b and the heat exchanger 7 that is disposed on the intake heating passage 13a side and heats the intake air. Intake air heating means and intake air cooling passage 13
The intake air cooling means, which is arranged on the b side and is achieved by the heat exchanger 8 that cools the intake air, and the intake air temperature that is mixed after passing through the intake air heating passage 13a and the intake air cooling passage 13b are detected. An ECU for feedback controlling the air temperature sensor 10 and the intake passage valve 5 according to the output of the intake air temperature sensor 10.
Intake passage valve feedback control means achieved by 20 and EGR valve opening calculation means achieved by the ECU 20 that calculates the target EGR valve opening degree SEGR of the EGR valve 4 based on the operating state of the internal combustion engine 1, According to the target EGR valve opening degree SEGR calculated by the EGR valve opening degree calculating means,
It is provided with an EGR valve control means that is achieved by the ECU 20 that controls the R valve 4, and this can be the embodiment of claim 3.

Therefore, the intake air is cooled by the intake passage valve feedback control means achieved by the ECU 20, and the intake air heating passage 13a in which the intake heating means achieved by the heat exchanger 7 is disposed and the intake air are cooled. Intake cooling passage 13 in which intake cooling means achieved by the heat exchanger 8 is arranged
The intake passage valve 5 is feedback-controlled in accordance with the output of the intake air temperature sensor 10 that detects the intake air temperature that has been mixed after passing through b. Also, E achieved by the ECU 20
The target EGR valve opening degree SEGR of the EGR valve 4 is calculated by the GR valve opening degree calculating means based on the operating state of the internal combustion engine 1, and the EGR valve control means is achieved by the ECU 20 according to the target EGR valve opening degree SEGR. The EGR valve 4 is controlled by.

Therefore, in the internal combustion engine using the device of the present embodiment, the intake air temperature and the EGR amount are controlled independently and appropriately, so that desired fuel efficiency improvement, emission reduction, knock avoidance or output can be achieved for each operating region. Improvements are achieved.

[0057]

As described above, according to the intake air temperature and EGR control device for the internal combustion engine of claim 1, the intake passage valve control means controls the intake passage valve, and the intake air heating means for heating the intake air is provided. The intake air temperature is adjusted after passing through the intake air heating passage provided and the intake air cooling passage provided with an intake air cooling means for cooling the intake air. Also, E
Based on the operating state of the internal combustion engine, the GR valve opening calculation means E
The EGR valve opening degree of the GR valve is calculated, and the EGR valve control means controls the EGR valve according to the EGR valve opening degree. As a result, the intake air temperature and the EGR amount are appropriately controlled independently, and desired fuel consumption improvement, emission reduction, knock avoidance, or output improvement is achieved for each operating region of the internal combustion engine.

Intake air temperature and EGR of the internal combustion engine according to claim 2
According to the control device, the intake passage valve opening calculation means is provided with an intake heating passage for heating the intake air based on the operating state of the internal combustion engine, and the intake cooling means for cooling the intake air. The intake passage valve opening degree of the intake passage valve corresponding to the intake air temperature after passing through the intake cooling passage and being mixed is calculated, and the intake passage valve control means intakes the intake air according to the intake passage valve opening degree. The passage valve is controlled. The EGR valve opening calculation means calculates the EGR valve opening of the EGR valve based on the operating state of the internal combustion engine, and the EGR valve control means controls the EGR valve according to the EGR valve opening. As a result, the intake air temperature and the EGR amount are appropriately controlled independently based on the operating state, and desired fuel consumption improvement, emission reduction, knocking avoidance, or output improvement is achieved for each operating region of the internal combustion engine.

Intake air temperature and EGR of the internal combustion engine of claim 3
According to the control device, the intake passage valve feedback control means passes through the intake heating passage in which the intake heating means for heating the intake air is arranged and the intake cooling passage in which the intake cooling means for cooling the intake air is arranged. The intake passage valve is feedback-controlled according to the output of the intake air temperature sensor that detects the intake air temperature to be mixed later. The EGR valve opening calculation means calculates the EGR valve opening of the EGR valve based on the operating state of the internal combustion engine, and the EGR valve control means controls the EGR valve according to the EGR valve opening. As a result, the intake air temperature and the EGR amount are appropriately controlled independently, and desired fuel consumption improvement, emission reduction, knock avoidance, or output improvement is achieved for each operating region of the internal combustion engine.

Intake air temperature and EGR of the internal combustion engine according to claim 4
According to the control device, the air passes through the two passages including the intake air heating passage in which the intake air heating means for heating the intake air is arranged and the intake air cooling passage in which the intake air cooling means for cooling the intake air is arranged. The intake air passage ratio is set. Then, the intake passage valve feedback control unit feedback-controls the intake passage valve in the direction in which knocking is avoided in accordance with the output of the knock sensor that detects the occurrence of knocking of the internal combustion engine. Further, the EGR valve feedback control means feedback-controls the EGR valve in the direction in which knocking is avoided according to the output of the knock sensor. As a result, the intake air temperature and the EGR amount are independently feedback-controlled as appropriate, and desired knocking avoidance is achieved for each operating region of the internal combustion engine.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a mechanical configuration of an intake air temperature and EGR control device for an internal combustion engine according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing an intake air temperature of an internal combustion engine and an electrical configuration of an EGR control device according to a first embodiment of the present invention.

FIG. 3 is a base routine of an intake air temperature of an internal combustion engine and an intake air temperature and an EGR control of an EGR control device according to a first embodiment of the present invention.

FIG. 4 is a subroutine for calculating an intake air temperature of an internal combustion engine and an EGR valve opening degree of an EGR control device according to a first embodiment of the present invention.

5 is a map for obtaining a basic EGR valve opening used in a subroutine for calculating an EGR valve opening in FIG.

FIG. 6 is an explanatory diagram showing the optimum intake air temperature and intake air temperature of the internal combustion engine according to the first embodiment of the present invention for each region corresponding to the operating state of the internal combustion engine.

FIG. 7 is an explanatory diagram showing each region of FIG. 6 in correspondence with the operating state of the internal combustion engine.

FIG. 8 is a characteristic diagram showing the relationship between the EGR amount and intake air temperature in the emission priority region of FIGS. 6 and 7.

9 is a characteristic diagram showing the relationship between intake air temperature and air expansion coefficient in the fuel consumption priority region of FIGS. 6 and 7. FIG.

10 is a characteristic diagram for obtaining a water temperature correction value from the cooling water temperature used in the subroutine for calculating the EGR valve opening degree in FIG.

11 is a characteristic diagram showing the relationship between the target EGR valve opening and the EGR amount in the EGR valve opening calculation subroutine of FIG.

FIG. 12 is a subroutine for calculating the intake air temperature of the internal combustion engine and the intake passage valve opening of the EGR control device according to the first embodiment of the present invention.

13 is a map for obtaining a basic intake passage valve opening used in a subroutine for calculating the intake passage valve opening in FIG.

FIG. 14 is a characteristic diagram for obtaining an intake air temperature correction value from an intake air temperature used in a subroutine for calculating the intake passage valve opening degree in FIG.

FIG. 15 is a characteristic diagram showing the relationship between the target intake passage valve opening and the intake temperature in the subroutine for calculating the intake passage valve opening in FIG.

FIG. 16 is a subroutine for driving the intake air temperature of the internal combustion engine and the intake passage valve of the EGR control device according to the first embodiment of the present invention.

FIG. 17 is a subroutine for driving the intake air temperature of the internal combustion engine and the EGR valve of the EGR control device according to the first embodiment of the present invention.

FIG. 18 is a schematic diagram showing a main part of a mechanical configuration of an intake air temperature and EGR control device of an internal combustion engine according to a second embodiment of the present invention.

FIG. 19 is a subroutine for calculating the intake air temperature of the internal combustion engine and the intake passage valve opening of the EGR control device according to the second embodiment of the present invention.

20 is a map for obtaining a target intake air temperature used in a subroutine for calculating an intake passage valve opening degree in FIG.

FIG. 21 is a subroutine for driving an intake air temperature of an internal combustion engine and an intake passage valve of an EGR control device according to a second embodiment of the present invention.

[Explanation of symbols]

 1 Internal Combustion Engine 2 Rotation Angle Sensor 3 Intake Pressure Sensor 4 EGR Valve 5 Intake Passage Valve 7,8 Heat Exchanger 9 Water Temperature Sensor 10 Intake Temperature Sensor 11 EGR Valve Opening Sensor 12 Intake Passage Opening Sensor 13a Intake Heating Passage 13b Intake Cooling passage 20 ECU (electronic control unit)

Claims (4)

[Claims] 1. An EGR valve for introducing an EGR gas, which is a part of exhaust gas taken out from an exhaust system of an internal combustion engine, into an intake system of the internal combustion engine, and an EGR valve formed in the intake passage of the intake system of the internal combustion engine. An intake passage valve that sets a passage ratio of intake air that passes through two passages including an intake heating passage and an intake cooling passage; an intake heating unit that is disposed on the intake heating passage side and that heats the intake air; An intake air cooling unit that is arranged on the cooling passage side and cools intake air; and an intake air that controls the intake passage valve and adjusts an intake air temperature that is mixed after passing through the intake heating passage and the intake cooling passage. The passage valve control means, and the EG of the EGR valve based on the operating state of the internal combustion engine.
EGR valve opening calculation means for calculating the R valve opening, and EGR valve control means for controlling the EGR valve according to the EGR valve opening calculated by the EGR valve opening calculation means. Intake air temperature and E of internal combustion engine
GR control device. 2. An EGR valve for introducing an EGR gas, which is a part of exhaust gas taken out from an exhaust system of an internal combustion engine, into an intake system of the internal combustion engine, and an EGR valve formed in the intake passage of the intake system of the internal combustion engine. An intake passage valve that sets a passage ratio of intake air that passes through two passages including an intake heating passage and an intake cooling passage; an intake heating unit that is disposed on the intake heating passage side and that heats the intake air; Intake cooling means arranged on the cooling passage side for cooling intake air, and corresponding to the intake air temperature after being mixed by passing through the intake heating passage and the intake cooling passage based on the operating state of the internal combustion engine Intake passage valve opening degree calculating means for calculating the intake passage valve opening degree of the intake passage valve, and controlling the intake passage valve according to the intake passage valve opening degree calculated by the intake passage valve opening degree calculating means Intake passage valve And control means, EG of the EGR valve based on the operating state of the internal combustion engine
EGR valve opening calculation means for calculating the R valve opening, and EGR valve control means for controlling the EGR valve according to the EGR valve opening calculated by the EGR valve opening calculation means. Intake air temperature and E of internal combustion engine
GR control device. 3. An EGR valve for introducing an EGR gas, which is a part of exhaust gas taken out from an exhaust system of an internal combustion engine, into an intake system of the internal combustion engine, and an EGR valve formed in the intake passage of the intake system of the internal combustion engine. An intake passage valve that sets a passage ratio of intake air that passes through two passages including an intake heating passage and an intake cooling passage; an intake heating unit that is disposed on the intake heating passage side and that heats the intake air; An intake air cooling means arranged on the cooling passage side for cooling the intake air; an intake air temperature sensor for detecting an intake air temperature mixed after passing through the intake air heating passage and the intake air cooling passage; Intake valve feedback control means for feedback controlling the intake passage valve according to the output of the EGR valve, and EG of the EGR valve based on the operating state of the internal combustion engine.
EGR valve opening calculation means for calculating the R valve opening, and EGR valve control means for controlling the EGR valve according to the EGR valve opening calculated by the EGR valve opening calculation means. Intake air temperature and E of internal combustion engine
GR control device. 4. An EGR valve for introducing EGR gas, which is a part of exhaust gas taken out from an exhaust system of an internal combustion engine, into an intake system of the internal combustion engine, and an EGR valve formed in the intake passage of the intake system of the internal combustion engine. An intake passage valve that sets a passage ratio of intake air that passes through two passages including an intake heating passage and an intake cooling passage; an intake heating unit that is disposed on the intake heating passage side and that heats the intake air; Intake air cooling means arranged on the cooling passage side for cooling the intake air, a knock sensor for detecting occurrence of knocking of the internal combustion engine, and feedback of the intake passage valve in a direction to avoid knocking according to the output of the knock sensor. Intake passage valve feedback control means for controlling, and EG for feedback controlling the EGR valve in a direction to avoid knocking according to the output of the knock sensor. An intake air temperature and EGR control apparatus for an internal combustion engine, comprising: R valve feedback control means.