JPH11153058A - Engine control device having idle intake pressure learning function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effect accurate reflection in correction of various highlands by accurately learning a pressure depending upon an atmospheric in an intake passage. SOLUTION: An engine control device arranged at an engine 11 and an idle intake pressure learning function comprises an exhaust reflux (EGR: Exhaust Gas Recirculation) control device 29; a throttle valve 45 arranged at an intake passage 27, a throttle opening sensor 65 to detect the opening of the valve; and an electronic control unit(ECU) 70. The EGR control device 29 comprises an EGR passage 32 to interconnect an exhaust passage 28 and the intake passage 27; an EGR valve 33 arranged in the middle of the EGR passage 32; and a valve lift sensor 64 to detect a lift amount. An ECU 70 corrects an intake pressure detected by an intake pressure sensor 62 during idling of the engine 11, based on a lift amount of the EGR valve 33 and the opening of the throttle valve 45.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine control device having an idle intake pressure learning function. More specifically, the present invention relates to an engine control device having a function of learning the variation of intake pressure depending on the atmospheric pressure during idling without providing an atmospheric pressure sensor. The present invention relates to an engine control device that performs a high altitude correction.

[0002]

2. Description of the Related Art Conventionally, when an engine is operated at a high altitude where the atmospheric pressure is low, it is necessary to perform correction (high altitude correction) of various engine control amounts, for example, a fuel injection amount, etc. in accordance with the fluctuation of the atmospheric pressure. The altitude correction is performed based on the atmospheric pressure. Therefore, when performing this high altitude correction, it is necessary to detect the atmospheric pressure as a premise.
Generally, the detection is performed based on an intake pressure detected by an intake pressure sensor provided in an intake passage of the engine.

[0003]

In recent years, in order to reduce nitrogen oxides (NOx) contained in exhaust gas, recently, an exhaust gas for returning a part of the exhaust gas flowing through an exhaust passage to an intake passage through an exhaust gas recirculation passage has been proposed. Reflux (EGR: Exhaust Gas Re)
circulation) Control devices are often provided in engine systems. In the engine system provided with the EGR control device as described above, when the atmospheric pressure is detected, the intake pressure in the intake passage fluctuates due to the amount of recirculated exhaust gas returned to the intake passage. Atmospheric pressure) cannot be detected. Therefore, E
Although a method of correcting the detected atmospheric pressure based on "existing" and "absent" of the exhaust gas recirculation by the GR control device is also conceivable, this method cannot cope with an exhaust gas recirculation amount that fluctuates as needed.

[0004] The intake pressure also varies depending on the opening of a throttle valve, an ISCV (idle control valve) and the like provided in the intake passage. Therefore, conventionally, for example, as in the device described in JP-A-7-180596,
Although a device for detecting the atmospheric pressure based on the ISCV opening, the engine speed, and the intake pressure is also known, if the exhaust gas recirculation amount or the like is complicatedly involved, the accurate detection will not be obvious.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to accurately learn a pressure depending on the atmospheric pressure in an intake passage and accurately reflect the learned pressure in various high altitude corrections. An object of the present invention is to provide an engine control device having an idle intake pressure learning function.

[0006]

In order to achieve the above object, an invention according to claim 1 is an exhaust gas recirculation control means for controlling exhaust gas recirculation from an exhaust passage to an intake passage and an exhaust gas recirculation section upstream of the intake passage. A control device that learns the intake pressure depending on the atmospheric pressure at the time of idling of the engine and performs various high altitude corrections, the intake pressure control device having an intake throttle valve that adjusts the opening degree of the passage. Intake pressure detection means for detecting, exhaust gas recirculation correction amount calculation means for calculating an intake pressure correction amount based on the exhaust gas recirculation control amount of the exhaust gas recirculation control means at the time of engine idling, And a learning means for learning an intake pressure dependent on the atmospheric pressure based on a corrected intake pressure value obtained by correcting the intake pressure.

According to this structure, the exhaust gas recirculation correction amount calculating means calculates the intake air pressure correction amount based on the exhaust gas recirculation control amount of the exhaust gas recirculation control means when the engine is idling.
Then, the learning means learns the intake pressure dependent on the atmospheric pressure based on the corrected intake pressure value corrected by the intake pressure correction amount. That is, since the intake pressure is corrected in accordance with the exhaust gas recirculation control amount, an accurate idle intake pressure can be learned even when the exhaust gas recirculation control into the intake passage is performed.

According to a second aspect of the present invention, there is provided an exhaust gas recirculation control means for controlling exhaust gas recirculation from the exhaust passage to the intake passage, and an intake throttle located upstream of the exhaust gas recirculation portion of the intake passage for adjusting the opening of the passage. A control device for learning an intake pressure depending on an atmospheric pressure at the time of idling of an engine equipped with a valve and performing various high altitude corrections, wherein an intake pressure detecting means for detecting a pressure in the intake passage; and An exhaust gas recirculation correction amount calculating means for calculating an intake air pressure correction amount based on the exhaust gas recirculation control amount of the exhaust gas recirculation control means; and the atmospheric pressure based on a value obtained by correcting the detected intake pressure by the calculated correction amount. Learning means for learning an intake pressure dependent on the air pressure, and correction means for correcting an exhaust gas recirculation control amount by the exhaust gas recirculation control means to a high altitude based on the learned intake pressure. The gist.

According to this configuration, the correction means corrects the amount of exhaust gas recirculation controlled by the exhaust gas recirculation control means to high altitude based on the idle intake pressure learned by the learning means. Further, learning of the idle intake pressure is performed based on the high-altitude corrected exhaust gas recirculation control amount. Therefore, the high altitude correction of the exhaust gas recirculation control amount is optimized, and the learning accuracy of the idle intake pressure is also increased.

According to a third aspect of the present invention, there is provided an exhaust gas recirculation control means for controlling exhaust gas recirculation from the exhaust passage to the intake passage, and an intake throttle located upstream of the exhaust gas recirculation portion of the intake passage for adjusting the opening of the passage. A control device for learning an intake pressure depending on an atmospheric pressure at the time of idling of an engine equipped with a valve and performing various high altitude corrections, wherein an intake pressure detecting means for detecting a pressure in the intake passage; and Exhaust gas recirculation correction amount calculating means for calculating an intake air pressure correction amount based on the exhaust gas recirculation control amount of the exhaust gas recirculation control means, and an intake pressure correction amount based on the opening degree adjustment amount of the intake throttle valve at the time of engine idling. Intake throttle correction amount calculating means, and learning means for learning the atmospheric pressure-dependent intake pressure based on a value obtained by correcting the detected intake pressure by the calculated correction amount. Further comprising the gist thereof.

According to this configuration, the exhaust gas recirculation correction amount calculating means calculates the intake air pressure correction amount based on the exhaust gas recirculation control amount of the exhaust gas recirculation control means when the engine is idling.
Further, the intake throttle correction amount calculating means calculates an intake pressure correction amount based on the opening degree adjustment amount of the intake throttle valve. Then, the learning means learns the intake pressure dependent on the atmospheric pressure based on a value obtained by correcting the detected intake pressure by the calculated correction amount. That is, since the intake pressure is corrected in accordance with the exhaust gas recirculation control amount and the opening degree of the intake throttle valve, accurate control is performed even when the exhaust gas recirculation control into the intake passage and the opening degree of the intake throttle valve are performed. The idle intake pressure can be learned.

According to a fourth aspect of the present invention, there is provided an exhaust gas recirculation control means for controlling exhaust gas recirculation from the exhaust passage to the intake passage, and an intake throttle located upstream of the exhaust gas recirculation portion of the intake passage for adjusting the degree of opening of the passage. A control device for learning an intake pressure depending on an atmospheric pressure at the time of idling of an engine equipped with a valve and performing various high altitude corrections, wherein an intake pressure detecting means for detecting a pressure in the intake passage; and Exhaust gas recirculation correction amount calculating means for calculating an intake air pressure correction amount based on the exhaust gas recirculation control amount of the exhaust gas recirculation control means, and an intake pressure correction amount based on the opening degree adjustment amount of the intake throttle valve at the time of engine idling. Intake throttle correction amount calculating means, and learning means for learning the atmospheric pressure-dependent intake pressure based on a value obtained by correcting the detected intake pressure by the calculated correction amount. A first correcting means for correcting the exhaust gas recirculation control amount by the exhaust gas recirculation control means to a high altitude based on the learned intake pressure; and an opening adjustment amount by the intake throttle valve based on the learned intake pressure to a high altitude. The gist of the present invention is to provide a second correction unit for performing correction.

According to this structure, the learning means determines the intake pressure dependent on the atmospheric pressure based on the value obtained by correcting the intake pressure by the correction amount calculated by the exhaust gas recirculation correction amount calculating means and the intake throttle correction amount calculating means. To learn. The first correction means corrects the amount of exhaust gas recirculation controlled by the exhaust gas recirculation control means at high ground based on the learned idle intake pressure, and the second correction means adjusts the intake throttle valve based on the learned idle intake pressure. The high-altitude correction is made for the opening adjustment amount due to. Further, learning of the idle intake pressure is performed based on the exhaust recirculation control amount corrected for the high altitude and the opening degree adjustment amount by the intake throttle valve. Therefore, the high ground correction of the exhaust gas recirculation control amount and the opening degree adjustment amount by the intake throttle valve is optimized, and the learning accuracy of the idle intake pressure is also increased.

According to a fifth aspect of the present invention, in the engine control apparatus having the idle intake pressure learning function according to the fourth aspect, the first and second correction means are set to be different targets at different times. The gist is to execute the high altitude correction of the control amount.

According to this configuration, the first and second correction means execute the high altitude correction of the target exhaust gas recirculation control amount and the opening degree adjustment amount by the intake throttle valve at different times. Therefore, both highland corrections can be performed without interference with each other, and the two highland corrections are further optimized.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 shows a diesel engine system to which an engine control device having an idle intake pressure learning function according to the present embodiment is applied. A diesel engine (hereinafter simply referred to as “engine”) 11 includes a cylinder block 12 in which a plurality of cylinders 14 (one of which is shown in the figure) are formed, and a cylinder head 13 assembled on the cylinder block 12. Have. A piston 15 is housed in each cylinder 14 so as to be able to reciprocate. The piston 15 is connected to a crankshaft 17 via a connecting rod 16.

The space above the piston 15 in the cylinder 14 is a main combustion chamber 18. The same number of sub-combustion chambers 19 as the cylinders 14 are formed below the cylinder head 13, and each sub-combustion chamber 19 is connected to the corresponding main combustion chamber 18 by an injection hole 21. An injection nozzle 22 is attached to the cylinder head 13, and its tip faces the sub-combustion chamber 19. This injection nozzle 22 is connected to a fuel injection pump 23 by a fuel conduit 24.

The fuel injection pump 23 is a well-known distribution pump, and its drive shaft 23a is drivingly connected to the crankshaft 17. The fuel injection pump 23 is driven by the rotation of the crankshaft 17 to supply the fuel to the injection nozzle 22 in an amount corresponding to the engine load. The fuel injection pump 23 includes a timer device for adjusting the fuel injection timing, a solenoid valve for adjusting the fuel injection amount (both not shown), and the like.

Each of the main combustion chambers 18 has a cylinder head 13.
, An intake port (not shown) and an exhaust port 25 are formed. Further, an intake valve (not shown) and an exhaust valve 26 are supported on the cylinder head 13 so as to be reciprocally movable, and the reciprocating movement opens and closes the intake port and the exhaust port 25. Further, the cylinder head 13 has an intake passage 2 communicating with an intake port.
7. An exhaust passage 28 communicating with the exhaust port 25 is connected to each. In the intake passage 27, a throttle valve (intake throttle valve) 45 for adjusting the amount of intake air and adjusting the negative pressure in the intake passage 27 is rotatably supported. The throttle valve 45 is connected to the accelerator pedal 41.
The rotation is controlled mechanically independently by an actuator 46 including, for example, a stepping motor or a DC motor and an electromagnetic clutch. The control of the actuator 46 is performed by an electronic control device described later.

Further, an exhaust gas recirculation (EG
R) A control device 29 is provided. The EGR control device 29 communicates with the exhaust passage 28 and the intake passage 27 through E
The vehicle includes a GR passage 32 and an EGR valve 33 provided in the middle of the EGR passage 32.

The EGR valve 33 includes a valve body 36 and a valve body 3
The valve seat 6 includes a valve seat 38 for taking off and seating, a diaphragm (not shown) connected to the valve body 36, and a negative pressure chamber (not shown) partitioned by the diaphragm. This negative pressure chamber is connected to a negative pressure pump (not shown) via a negative pressure adjusting valve 39. The negative pressure adjusting valve 39 is an electromagnetic valve operated by an electric signal, and adjusts a negative pressure supplied from the negative pressure pump and acting on the negative pressure chamber to a magnitude corresponding to the electric signal.

In the EGR control device 29, the magnitude of the negative pressure in the negative pressure chamber is adjusted by the negative pressure adjusting valve 39,
The diaphragm bends in response to the negative pressure, so that the valve body 3
6 lifts. And, with this lift, the valve element 36
And the distance between the valve seat 38 and the EGR is adjusted.
The opening of the valve 33 is adjusted. The amount of exhaust gas recirculated from the exhaust passage 28 to the intake passage 27 through the EGR passage 32, that is, the EGR amount is determined according to the opening of the EGR valve 33.

The engine 11 is provided with various sensors for detecting the operation state. The fuel injection pump 23 has a rotation speed sensor 6 that detects the rotation speed of the drive shaft 23a, that is, the rotation speed of the crankshaft 17, and outputs a signal corresponding to the rotation speed.
0 is built in. The engine speed NE is calculated based on the rotation speed. The cylinder block 12 detects the temperature of the cooling water (cooling water temperature) THW,
A water temperature sensor 61 that outputs a signal corresponding to the temperature is attached.

In the intake passage 27, the throttle valve 4
5, the intake pressure PM in the intake passage 27 is
Is provided with an intake pressure sensor 62 that outputs a signal corresponding to the intake pressure PM.

In the vicinity of the throttle valve 45, a throttle opening sensor 65 for detecting the opening of the throttle valve 45 is provided. EGR valve 3
3 is provided with a valve lift sensor 64 for detecting the valve lift of the EGR valve 33.
The valve lift sensor 64 detects the EGR amount by detecting the lift amount of the valve body 36, that is, the opening degree of the EGR valve 33.

An accelerator position sensor 6 for detecting an accelerator position is located near the accelerator 41.
3 are provided. The accelerator position sensor 63 also has a function of an idle switch that detects an amount of depression of the accelerator 41, that is, an idle state, and outputs an idle signal.

Each of these sensors 60 to 65 is connected to an electronic control unit (hereinafter referred to as “ECU”) 70 provided in the vehicle.
It outputs a detection signal corresponding to W, intake pressure PM, throttle opening, valve lift, and accelerator position.

The ECU 70 includes a central processing unit (CPU) for performing arithmetic processing, a read-only memory (ROM) in which a predetermined control program and function data are stored in advance, a CPU
Random access memory (RAM) for temporarily storing the calculation results and the like, a backup RAM for storing the CPU calculation results and the like in a nonvolatile manner, an input circuit to which the sensors 60 to 65, etc. are connected, and the negative pressure adjusting valves 39 And an output circuit to which the timer device and the solenoid valve of the fuel injection pump 23 are connected are connected by a bus. ECU 70
Are based on detection signals from the sensors 60 to 65, based on the negative pressure regulating valve 39, the throttle valve 45, the fuel injection pump 2
By controlling 3 and the like, EGR amount control, intake throttle control, fuel injection timing control, fuel injection amount control, and the like are executed.

The engine control device having the function of learning the idle intake pressure according to the present embodiment includes the EGR control device 29, the throttle valve 45, the intake pressure sensor 62, the valve lift sensor 64, the throttle opening sensor 65, and the ECU 70. And so on.

Next, a processing procedure relating to idle intake pressure learning by the engine control apparatus having the idle intake pressure learning function having the above-described configuration, and then to a high altitude correction performed based on the idle intake pressure obtained by the idle intake pressure learning. The processing procedure will be described with reference to FIGS.
Here, the idle intake pressure is an intake pressure learned at the time of engine idling and depends on the atmospheric pressure.

FIG. 2 is a flowchart showing a processing routine of "idle intake pressure learning processing". ECU 70
(Accurately, the CPU in the ECU 70) executes this processing routine by interruption every predetermined time (for example, every 1 second (second)).

In step S10 shown in FIG.
U70 reads the detection data from the various sensors.
That is, the ECU 70 reads detection data from the rotation speed sensor 60, the water temperature sensor 61, the intake pressure sensor 62, the accelerator position sensor 63, the valve lift sensor 64, and the throttle opening sensor 65, respectively. Then, the ECU 70, based on the read data,
The engine speed NE, cooling water temperature THW, intake pressure PM, accelerator depression amount, EGR amount, and throttle opening are respectively calculated. When an idle signal is read from the accelerator position sensor 63, the idle state is detected.

Next, at step S20, the ECU 7
0 determines whether or not the condition for learning the idle intake pressure is satisfied. The conditions for learning the idle intake pressure are as follows, for example.

1. 1. Stable idle state 2. The cooling water temperature THW is equal to or higher than a predetermined value. Other than when the engine stalls 4. 4. IG (ignition switch) is ON. Normal operation of the throttle valve If all these learning conditions are satisfied, the next step S3
If the learning condition is not satisfied, the learning routine of the idle intake pressure is not performed, and the processing routine of the "idle intake pressure learning process" is temporarily terminated.

In the following step S30, the ECU 70
Reads an idle intake pressure correction amount evgecm based on the EGR amount calculated in step S10 from a data map stored in a built-in ROM. This EGR amount and EGR
FIG. 4 shows a data map of the correction amount evgecm in a graph. As shown in FIG. 4, the EGR amount and the EGR correction amount evgecm have a substantially linear relationship, and the data map is determined in advance by the inventors through experiments and the like.

In the following step S40, the ECU 70
Reads the correction amount of the idle intake pressure (hereinafter simply referred to as throttle correction amount) evglscm based on the throttle opening calculated in step S10 from the data map similarly stored in the built-in ROM.
This throttle opening and the throttle correction amount evglscm
FIG. 5 is a graph showing the data map shown in FIG. As shown in FIG. 5, the throttle correction amount evglscm does not have a linear relationship with the throttle opening, but changes abruptly when the throttle opening is small. The amount of change is small. This data map is also determined in advance by experiments and the like.

In the next step S50, the EG
R correction amount evgecm and throttle correction amount evgls
The intake pressure PM calculated in step S10 based on cm is corrected according to the following equation. Where the intake pressure PM
Is a corrected intake pressure evpstd. evpstd = PM−evgecm−evglscm (1) That is, as shown in the equation (1), the ECU 70 subtracts the EGR amount and the correction amount based on the throttle opening from the intake pressure PM, that is, the EGR amount and Corrected intake pressure evpst by removing the amount of air pressure that depends on the throttle opening
This is stored in the built-in backup RAM as d. Therefore, accurate idle intake pressure learning can be performed without depending on the EGR amount and the throttle opening at the time of idle intake pressure learning.

In the following step S60, the calculated corrected intake pressure evpstd is compared with the previous learned intake pressure EV.
It is determined whether it is smaller than GPIM (i-1). The corrected intake pressure evpstd is equal to the previous learned intake pressure EVGPI.
If it is smaller than M (i-1), the routine goes to step S80, where the corrected intake pressure evpstd is stored as it is as the current learned intake pressure EVGPIMi in the backup RAM containing it.

In this case, the current learned intake pressure (corrected intake pressure) is lower than the previous learned intake pressure, that is, the altitude is higher in the current intake pressure learning than in the previous intake pressure learning. This corresponds to the case where the vehicle is currently traveling on an uphill slope.

On the other hand, if the corrected intake pressure evpstd is not smaller than the previous learned intake pressure EVGPIM (i-1), that is, the previous learned intake pressure EVGPIM (i-1)
If it is greater than or equal to, the process moves to step S70.

In step S70, the current corrected intake pressure evpstd is set to the previous learned intake pressure EVGPIM (i
-1) is equal to or greater than the predetermined learning intake pressure EVGPIM (i-1) and a predetermined learning hysteresis EK is set.
A determination is made whether it is less than the sum of VGPDL (atmospheric pressure value).

Here, the learning hysteresis EKVG
The reason why the PDL is provided is that hunting (vibration of the control amount) occurs in the EGR amount control due to a slight change in the learned intake pressure EVGPIMi because the EGR amount control is performed based on the learned intake pressure EVGPIMi as described later. This is to prevent

Here, the corrected intake pressure evpstd is equal to or larger than the previous learned intake pressure EVGPIM (i-1) and smaller than the sum of the previous learned intake pressure EVGPIM (i-1) and the learning hysteresis EKVGPDL. When it is determined that the current intake air pressure evpstd (i-1) is the current learned intake air pressure EVGPIMi, the process proceeds to step S90, where the backup RA is stored.
Stored in M.

In this case, the previous learned intake pressure EVGPI
Since the current corrected intake pressure evpstd is slightly higher than M (i-1) so as not to exceed the learning hysteresis EKVGPDL, this corresponds to the case where the vehicle is currently traveling on almost flat terrain or a gentle downhill. I do.

On the other hand, if the current corrected intake pressure evpstd is equal to or greater than the value obtained by adding the learning hysteresis EKVGPDL to the previous learned intake pressure EVGPIM (i-1), the process proceeds to step S100.

In step S100, the learning hysteresis EKVGPD is calculated from the current corrected intake pressure evpstd.
The value obtained by subtracting L is stored as a current learned intake pressure EVGPIMi in a backup RAM containing the learned intake pressure EVGPIMi.

In this case, the current corrected intake pressure evpst
The fact that d is larger than the value obtained by adding the learning hysteresis EKVGPDL to the previous learned intake pressure EVGPIM (i-1) corresponds to the case where the vehicle is currently traveling on a downgrade.

The initial value of the learned intake pressure EVGPIMi is set to a predetermined value higher than the normal atmospheric pressure value, that is, a value at which the EGR amount control is always performed. This step S
When 100 is completed, the processing routine of the "idle intake pressure learning process" is temporarily terminated. Then, as described above, this routine is repeated at regular intervals.

Next, the processing routine of the "high altitude correction processing" performed based on the learned intake pressure EVGPIMi will be described. FIG. 3 is a flowchart showing a processing routine of the “high altitude correction processing”, and the ECU 70 similarly executes this processing routine at predetermined time intervals (for example, at “8 ms (milliseconds)”).

First, in step S210 shown in FIG. 3, the ECU 70 performs a high altitude correction of the EGR amount based on the learned intake pressure EVGPIMi stored in the backup RAM. Specifically, this high altitude correction of the EGR amount
High ground correction multiplication coefficient (hereinafter referred to as EGR multiplication coefficient) mepi of the EGR amount corresponding to the learned intake pressure EVGPIMi
m. The EGR multiplication coefficient me
pim is E from the data map stored in the ROM in advance.
These are read separately by the CU 70 and stored in a predetermined area of the built-in RAM. This learning intake pressure E
FIG. 6 shows a data map of VGPIMi and the EGR multiplication coefficient mepim in a graph, for example.

Here, the ECU 70 reads the EGR multiplication coefficient mepim from the RAM, and reads the engine speed N
A basic EGR amount obtained based on a two-dimensional map (not shown) of E and load (fuel injection amount) is corrected by the EGR multiplication coefficient mepim, cooling water temperature THW, and the like, and stored in a built-in RAM. Then, the ECU 70 separately controls the negative pressure adjusting valve 39, the EGR valve 33, and the like so as to obtain the EGR amount corrected for the high altitude. Further, based on the EGR amount corrected for high altitude, the EGR
The correction amount evgecm is determined.

As shown in FIG. 6, the learned intake pressure EVG
When the PIMi is equal to or less than the A value, the EGR multiplication coefficient mepim is “0”, and the calculated EGR amount is also “0”. That is, when the traveling altitude of the vehicle reaches a predetermined altitude and the learned intake pressure EVGPIMi reaches the A value, the EG for black smoke prevention or the like is prevented.
The high altitude correction of the R amount ends. Note that the learned intake pressure EVGP
IMi decreases with increasing altitude.

In the next step S220, the above E
It is determined whether or not the high altitude correction of the GR amount has been completed.
That is, as described above, it is determined whether or not the learned intake pressure EVGPIMi reaches the predetermined altitude and the learned intake pressure EVGPIMi reaches the A value, and the EGR control is terminated. If it is determined that the EGR control is still ongoing, the processing routine is temporarily ended.

On the other hand, if it is determined that the EGR control has been completed, the flow shifts to step S230. This step S2
At 30, a high altitude correction of the throttle opening is performed. The high altitude correction of the throttle opening is performed based on the learned intake pressure EVGPIMi stored in the backup RAM, similarly to the high altitude correction of the EGR amount. Specifically, the high altitude correction of the throttle opening is based on the learned intake pressure EVGPI.
This is performed based on a high altitude correction multiplication coefficient (hereinafter, referred to as a throttle multiplication coefficient) emlpim of the throttle opening corresponding to Mi. Note that this throttle multiplication coefficient emlpi
m is the same as the EGR multiplication coefficient mepim,
The data is separately read from the data map stored in M by the ECU 70 and stored in a predetermined area of the built-in RAM. FIG. 7 is a graph showing a data map of the learned intake pressure EVGPIMi and the throttle multiplication coefficient emlpim, for example.

Here, the ECU 70 reads out the throttle multiplication coefficient emlpim from the RAM, and similarly obtains the basic throttle opening obtained based on a two-dimensional map (not shown) of the engine speed NE and the load (fuel injection amount). To the throttle multiplication coefficient emlpim and the cooling water temperature THW
And the like, and store it in the built-in RAM. Then, the ECU 70 controls the driving of the actuator 46 so as to obtain the throttle opening corrected at the high altitude. Further, the throttle correction amount evglscm is determined based on the throttle opening corrected at the high altitude.

Here, as described above, since the high altitude correction of the throttle opening is performed after the high altitude correction of the EGR amount is completed, accurate high altitude correction can be performed without interference from each other. The relationship between the high altitude correction processing of the throttle opening and the high altitude correction processing of the EGR amount is shown in FIG.
Shown in As shown in FIG. 8, when the traveling altitude of the vehicle reaches a predetermined altitude and the learned intake pressure EVGPIMi reaches the A value, the two processes are interchanged.

When step S230 ends, the processing routine of the "high altitude correction process" ends once. As described above, this routine is repeated at regular intervals. The effects obtained by the above-described embodiment will be described below.

In the present embodiment, the learning of the idle intake pressure (EVGPIMi) is determined by the EGR correction amount evgec.
m and the throttle correction amount evglscm. Therefore, an accurate idle intake pressure (E) can be obtained without depending on the EGR amount and the throttle opening during the learning.
VGPIMi) learning becomes possible. Further, the high altitude correction of the EGR amount and the throttle opening performed based on the learned intake pressure EVGPIMi is also optimized.

In this embodiment, the high altitude correction processing of the throttle opening is performed after the high altitude correction processing of the EGR amount is completed, that is, after it is confirmed that the EGR amount has become “0”. Will be Therefore, both highland correction processes can be performed accurately without interference between the two highland correction processes.
As a result, the idle intake pressure learning performed based on the EGR amount and the throttle opening becomes more accurate.

The present embodiment can be implemented by changing the configuration as follows. In the present embodiment, the opening of the EGR valve 33 is adjusted by controlling the negative pressure adjusting valve 39. On the other hand, the opening degree of the EGR valve may be adjusted using a stepping motor. In this configuration,
Based on the number of pulse signals output from the ECU 70 to the stepping motor, the opening degree of the EGR valve, that is, E
The GR amount can be grasped. Therefore, the valve lift sensor 64 becomes unnecessary. Further, even when the negative pressure adjusting valve 39 is used, the EGR
If the opening of the valve can be estimated, the valve lift sensor 64 becomes unnecessary.

In this embodiment, as shown in FIG. 8, the high altitude correction processing of the EGR amount is first performed at a low altitude, and the high altitude correction processing of the throttle opening is started after the high altitude correction processing is completed. Is not limited to this. For example, contrary to the present embodiment, the high altitude correction processing of the throttle opening may be performed first, and the high altitude correction processing of the EGR amount may be started after the high altitude correction processing is completed, or both processings may be performed. May be performed in a time-sharing manner regardless of the altitude. In short, any form may be used as long as both forms are not performed simultaneously.

In this embodiment, an example is shown in which a turbocharger is not provided in a diesel engine system to which an engine control device having an idle intake pressure learning function is applied. However, a configuration in which a turbocharger is provided in the engine system may be adopted. Good. When a turbocharger is provided in the engine system, the intake pressure may be replaced with the supercharging pressure. That is, the intake pressure sensor 62
Is the supercharging pressure.

In the present embodiment, an example has been described in which an engine control device having an idle intake pressure learning function is applied to a diesel engine system, but the engine control device may be applied to a gasoline engine system.

In the present embodiment, the example of the idle intake pressure learning based on the EGR amount and the throttle opening is shown, but the idle intake pressure learning based only on the EGR amount is also significant.

The control using the learning value of the idle intake pressure shown in the present embodiment is not limited to the EGR amount and the throttle opening. For example, the fuel injection amount and the injection timing, and the ignition timing control for a gasoline engine is used. Etc. can be applied effectively.

In addition, technical ideas other than the claims that can be grasped from the above embodiment will be described below together with their effects. (1) In the engine control device having an idle intake pressure learning function according to any one of claims 1 to 5, the learning means includes means for, when the corrected intake pressure value is smaller than the previously learned intake pressure, the corrected intake pressure. When the corrected intake pressure value is equal to or higher than the previously learned intake pressure and is smaller than the value obtained by adding a predetermined learning hysteresis to the previously learned intake pressure, the corrected intake pressure value at the time of the previous learning is used. Is the learned intake pressure, and if the corrected intake pressure value is equal to or higher than the previously learned intake pressure and is equal to or greater than a value obtained by adding a predetermined learning hysteresis to the previously learned intake pressure, the learning is performed from the previously learned intake pressure. An engine control device having an idle intake pressure learning function, wherein a value obtained by subtracting hysteresis is used as a learned intake pressure.

According to this configuration, by providing the learning hysteresis, it is possible to prevent the hunting of the EGR amount control due to a slight change in the learning intake pressure in the EGR amount control performed based on the idle learning intake pressure. it can.

[0069]

According to the first aspect of the present invention, accurate idle intake pressure learning can be performed even when the exhaust gas recirculation control into the intake passage is performed.

According to the second aspect of the present invention, the high altitude correction of the exhaust gas recirculation control amount is optimized, and the learning accuracy of the idle intake pressure is also increased. According to the third aspect of the present invention, accurate idle intake pressure learning can be performed even when exhaust gas recirculation control into the intake passage and opening adjustment of the intake throttle valve are performed.

According to the fourth aspect of the present invention, the high altitude correction of the exhaust gas recirculation control amount and the opening adjustment amount by the intake throttle valve is optimized, and the learning accuracy of the idle intake pressure is further increased.

According to the fifth aspect of the invention, the high altitude correction of the exhaust gas recirculation control amount and the opening degree adjustment amount by the intake throttle valve is further optimized.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a configuration of an embodiment of an engine control device having an idle intake pressure learning function according to the present invention.

FIG. 2 is a flowchart showing a processing procedure related to idle intake pressure learning.

FIG. 3 is a flowchart illustrating a processing procedure related to a high altitude correction processing.

FIG. 4 is an explanatory diagram showing a relationship between an EGR amount and an intake pressure correction amount thereof.

FIG. 5 is an explanatory diagram showing a relationship between a throttle opening and an intake pressure correction amount thereof.

FIG. 6 is an explanatory diagram showing a relationship between a learned intake pressure and an EGR correction coefficient.

FIG. 7 is an explanatory diagram showing a relationship between a learned intake pressure and a throttle opening correction coefficient.

FIG. 8 is an explanatory diagram showing a relationship between EGR correction and throttle opening correction.

[Explanation of symbols]

11: diesel engine, 27: intake passage, 28: exhaust passage, 29: EGR control device, 32: EGR passage, 3
3 EGR valve, 45 throttle valve, 62 intake pressure sensor, 64 valve lift sensor, 65 throttle opening sensor, 70 ECU.

Claims (5)

[Claims] An engine provided with an exhaust gas recirculation control means for controlling exhaust gas recirculation from an exhaust passage to an intake passage, and an intake throttle valve upstream of an exhaust gas recirculation section of the intake passage for adjusting an opening degree of the passage when the engine is idling. What is claimed is: 1. A control device for learning various intake pressures dependent on atmospheric pressure and performing various high altitude corrections, comprising: an intake pressure detecting means for detecting a pressure in the intake passage; Exhaust recirculation correction amount calculating means for calculating an intake pressure correction amount based on the amount; intake pressure dependent on the atmospheric pressure based on a corrected intake pressure value obtained by correcting the detected intake pressure by the calculated correction amount. An engine control device having an idle intake pressure learning function, comprising: learning means for learning. 2. The engine according to claim 1, further comprising an exhaust gas recirculation control means for controlling exhaust gas recirculation from the exhaust passage to the intake passage, and an intake throttle valve upstream of the exhaust gas recirculation section of the intake passage for adjusting the opening of the passage. What is claimed is: 1. A control device for learning various intake pressures dependent on atmospheric pressure and performing various high altitude corrections, comprising: an intake pressure detecting means for detecting a pressure in the intake passage; An exhaust gas recirculation correction amount calculating means for calculating an intake pressure correction amount based on the amount; and an intake pressure dependent on the atmospheric pressure is learned based on a value obtained by correcting the detected intake pressure by the calculated correction amount. Idle intake pressure, comprising: learning means; and correction means for correcting the amount of exhaust gas recirculation controlled by the exhaust gas recirculation control means to high altitude based on the learned intake pressure. The engine control device having a learning function. 3. An engine provided with an exhaust gas recirculation control means for controlling exhaust gas recirculation from the exhaust passage to the intake passage and an intake throttle valve upstream of the exhaust gas recirculation portion of the intake passage for adjusting the opening of the passage. What is claimed is: 1. A control device for learning various intake pressures dependent on atmospheric pressure and performing various high altitude corrections, comprising: an intake pressure detecting means for detecting a pressure in the intake passage; Exhaust recirculation correction amount calculation means for calculating an intake pressure correction amount based on the amount; intake throttle correction amount calculation means for calculating an intake pressure correction amount based on the opening degree adjustment amount of the intake throttle valve during engine idling; Learning means for learning an intake pressure dependent on the atmospheric pressure based on a value obtained by correcting the detected intake pressure by the calculated correction amount. Idle intake pressure the engine controller having a learning function. 4. An engine equipped with an exhaust gas recirculation control means for controlling exhaust gas recirculation from the exhaust passage to the intake passage and an intake throttle valve upstream of the exhaust gas recirculation portion of the intake passage for adjusting the opening of the passage. What is claimed is: 1. A control device for learning various intake pressures dependent on atmospheric pressure and performing various high altitude corrections, comprising: an intake pressure detecting means for detecting a pressure in the intake passage; Exhaust recirculation correction amount calculation means for calculating an intake pressure correction amount based on the amount; intake throttle correction amount calculation means for calculating an intake pressure correction amount based on the opening degree adjustment amount of the intake throttle valve during engine idling; Learning means for learning an intake pressure dependent on the atmospheric pressure based on a value obtained by correcting the detected intake pressure by the calculated correction amount; A first correction means for correcting the amount of exhaust gas recirculation controlled by the exhaust gas recirculation control means to a high altitude, and a second correction means for correcting the amount of opening adjustment by the intake throttle valve to a high altitude based on the learned intake pressure. An engine control device having an idle intake pressure learning function, comprising: 5. An engine control apparatus having an idle intake pressure learning function according to claim 4, wherein said first and second correction means execute the high altitude correction of the respective controlled variables at different times. An engine control device having an idle intake pressure learning function.