JP2560777B2 - Exhaust gas recirculation device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an exhaust gas recirculation device used in an internal combustion engine of an automobile or the like, and more specifically, to a recirculation amount corresponding to individual differences of the device or changes over time. This is to learn and correct the valve opening start drive force of the control valve.

<Conventional technology> An exhaust gas recirculation system (hereinafter referred to as EGR (Exhaust Gas Recir
culation) device). This EGR device is a device for reducing nitrogen oxides (hereinafter referred to as NOx), which are the most difficult to purify among harmful exhaust gases of automobiles. NOx is generated in the combustion chamber of the engine, and the combustion of the air-fuel mixture becomes close to complete combustion, and the generation amount increases as the combustion temperature increases. Therefore, the EGR device achieves the above-mentioned object by introducing a part of the exhaust gas, which is an inert gas (hereinafter, EGR gas), into the combustion chamber together with the fresh intake air to lower the combustion temperature.

The generation rate of NOx decreases as the mixing ratio of EGR gas to the intake air (hereinafter, EGR rate) increases. However, as a matter of course, at the same time, the engine output decreases due to the deterioration of the ignitability of the air-fuel mixture, so the EGR rate must be increased or decreased according to the operating state of the engine.

The EGR rate is increased / decreased by opening / closing a recirculation amount control valve (hereinafter, EGR valve) provided in an EGR gas passage that connects the exhaust system and the intake system. The EGR valve opening / closing control method has traditionally been
Pneumatic control using the intake pipe negative pressure and the exhaust pressure was generally performed. However, due to the fact that pneumatic control cannot perform complicated control for various engine operating conditions, the demand for exhaust gas purification has increased further, and the development of a centralized control system for the engine,
Currently, electronically controlled systems have become the mainstream.

In the electronically controlled EGR device, the EGR valve is opened and closed so as to have a pre-programmed EGR rate according to the engine speed, load, and the like. As a drive source of the EGR valve, a pulse motor or the like is used in addition to the negative pressure, and in many cases, feedback control is also performed. Hereinafter, as an example of an electronic control type EGR device, EGR valve lift feedback scheme, and Briefly the construction and operation of the intake pipe O ₂ sensor output feedback scheme.

What is the EGR valve lift feedback system?
As disclosed in Japanese Patent No. 11214, it is a system that includes a drive means for driving the opening and closing of the EGR valve and a detection means for detecting the opening amount of the EGR valve, and drives the EGR valve according to the operating state of the engine. The feedback control is performed so that the valve opening amount becomes a predetermined value. An intake pipe negative pressure, a pulse motor or the like is used as the driving means, and a potentiometer or the like is used as the valve opening amount detecting means.

Also, with the intake pipe O ₂ sensor output feedback method,
As shown in JP-60-138264, a method comprising driving means for opening and closing the EGR valve, and O ₂ sensor disposed in an intake pipe. In this method, the EGR valve is driven according to the operating condition of the engine, the actual EGR rate is calculated using the oxygen concentration measured by the O ₂ sensor, and the deviation from the target EGR rate is detected to perform feedback control. is there. As an O ₂ sensor,
A solid electrolyte oxygen pump type oxygen concentration measuring device or the like is used.

<Problems to be Solved by the Invention> However, each of the above-mentioned methods has the following problems.

In the EGR valve lift feedback system, durability is difficult because a large acceleration continuously acts on the valve opening amount detection means that moves integrally with the valve body. Further, since this method detects the opening amount of the EGR valve instead of the actual EGR rate, even if the actual EGR rate changes due to wear of the EGR valve, carbon deposition, etc., correction for that cannot be performed.

In the O ₂ sensor output feedback method, the feedback control is performed using the actual EGR rate, so the accuracy of the control under a constant load condition is excellent, but there is a time lag from the EGR valve operation until the actual EGR rate is measured. As a result, hunting occurs and the responsiveness during transition is difficult. Therefore, the negative pressure, which is the driving force of the EGR valve, the motor output, and the like are calculated based on the valve opening start driving force of the EGR valve, while the control that incorporates the proportional integration method is performed. However, the valve opening start driving force itself is not constant due to the disparity between solids of the EGR valve and changes with time such as carbon deposition, which impedes accurate control. In addition, when the EGR gas is not recirculated during idle operation, it is common to drive the EGR with the valve opening start driving force to improve the responsiveness. If the value is not high, the response may be deteriorated or unnecessary EGR may occur.

<Means for Solving the Problems> Therefore, in the present invention, an exhaust gas for reducing the nitrogen oxide concentration in the exhaust gas by introducing a part of the exhaust gas of the internal combustion engine into the intake system to lower the combustion temperature. In the recirculation device, an operating condition measuring means for measuring the operating condition of the internal combustion engine, a recirculation amount control valve provided in the exhaust gas recirculation passage for increasing and decreasing the recirculation amount by opening and closing the passage, A control valve driving means for driving the circulation amount control valve, a gas concentration detector for detecting the exhaust gas recirculation amount, and a target exhaust gas recirculation amount are determined based on the measurement result of the operating state measuring means. Then, while controlling the opening and closing of the recirculation amount control valve by using the control valve driving means so that the valve opening amount according to the target exhaust gas recirculation amount, the exhaust gas determined from the operating conditions of the internal combustion engine Recycle When the absence state continues for a certain period of time, the control valve drive means is used to apply a progressive driving force to the recirculation amount control valve and the exhaust gas recirculation start time is detected by the gas concentration detector, The control means for learning and correcting the data of the valve opening start driving force of the recirculation amount control valve is provided.

<Operation> In the exhaust gas recirculation device according to the present invention, after determining the recirculation amount based on the measurement result of the operating state measuring means,
While the exhaust gas recirculation is performed by driving the recirculation amount control valve using the control valve driving means, the recirculation amount control valve is gradually changed while the exhaust gas recirculation is stopped and the recirculation amount control valve is opened. The gas concentration detector detects the recirculation start time and learns and corrects the valve opening start driving force data.

<Examples> An example in which the present invention is applied to an engine with an electronically controlled fuel injection device (hereinafter, ECI) will be specifically described with reference to the drawings.

FIG. 1 schematically shows the entire centralized control system in the present embodiment, and FIG. 2 shows the hardware configuration of an electronic control unit (hereinafter referred to as an ECU) which is a control center of the centralized control system. Further, FIGS. 3 and 4 show control flowcharts of the main routine and the idle learning routine in this embodiment, respectively. 5 shows a target EGR rate, FIG. 6 shows a flow rate characteristic of the EGR valve with respect to control negative pressure, and FIG. 7 shows a duty ratio of the solenoid valve.

As shown in FIG. 1, in an engine E, an injector 1 for injecting fuel, a spark plug 2 for ignition, and an EG
The opening degree of the R valve 3 is all under the control of the ECU 4. E
The CU 4 drives and controls these controlled devices (injector 1, spark plug 2, EGR valve 3) based on various data. Below, an outline of the sensors for collecting various data used by the ECU 4 and the operation of the controlled device will be described along the flow of intake air.

The air sucked at a negative pressure from the air cleaner 5 by the lowering of the piston E ₁ in the engine E is guided to the Karman vortex type air flow meter 6, the intake air temperature sensor 7 and the atmospheric pressure sensor 8, and the intake air amount, the intake air temperature and the large intake air temperature are increased. Barometric pressure is detected. The air flowing into the intake pipe 9 is a butterfly type throttle valve 10
The opening of the throttle valve 10 is detected by a throttle sensor 11.

A negative pressure outlet pipe 12 and an EG are provided on the intake pipe wall downstream of the throttle valve 10.
The R gas inlet pipe 13 is connected and opened in order, and the negative pressure outlet pipe 1
Air is sucked into the intake pipe 9 from the EGR gas introduction pipe 13 and EGR gas is sucked into the intake pipe 9 from the EGR gas introduction pipe 13. The intake air is mixed with this EGR gas, and the oxygen concentration is detected by an O ₂ sensor 14 provided downstream. The O ₂ sensor 14 is the same as that described in the section of the related art.

Nearby combustion chamber E ₂ side end portion of the intake pipe 9, the injector 1 for the number of cylinders is provided, opens a command from ECU 4, to inject fuel in an amount each of the cylinders is required.
Fuel is pressure-fed from a fuel tank (not shown) to the injector 1 by a fuel pump (not shown).

In the figure, 15 is a water temperature sensor, which detects the cooling water temperature.

The fuel injection from the injector 1 causes the air that has become an air-fuel mixture to be sucked into the combustion chamber E ₂ and ignited by the ignition plug 2 near the compression top dead center. In Fig. 1, due to space limitations,
Are Eka to a remote location, but the ignition plug 2 Naturally faces its front end into the combustion chamber E _2. A high voltage from an ignition coil 16 is sent to the ignition plug 2 via a distributor 17. The power transmission timing (ignition timing) is calculated in the ECU 4, and the calculation result drives the ignition coil 16 via the power transistor 18.
The distributor 17 has a built-in crank angle sensor 19 and a cylinder discrimination sensor 20 in order to detect the rotation state of the engine.

When the explosion and expansion processes are completed, the air-fuel mixture becomes exhaust gas, most of which passes through the exhaust pipe 21 and the catalyst 21a.
After the harmful components are burned in the inside, they are released into the atmosphere from a muffler (not shown).

Then, a part of the exhaust gas is guided as an EGR gas to the EGR gas extraction pipe 22, and the amount thereof is controlled by the EGR valve 3, and the above-described E
The gas is introduced from the GR gas introduction pipe 13 into the intake pipe 9.

The EGR valve 3 operates by the negative pressure from the negative pressure extraction pipe 12 described above, and this negative pressure is turned on in the conduit of the negative pressure extraction pipe 12.
It is adapted to increase and decrease by opening and closing the -OFF type solenoid valve 23. In FIG. 1, reference numeral 24 is a communication pipe having a filter 25 attached to its end and an orifice 24a provided in a pipe line. The communication pipe 24 is for gradually introducing the atmosphere into the EGR valve 3 to close the EGR valve 3 when the passage of the negative pressure extraction pipe 12 is closed by the solenoid valve 23. Solenoid valve 23
Is opened / closed by a command from the ECU 4, and its control method is a variable duty ratio type.

The ECU 4 changes the duty ratio of the solenoid valve 23 so that the EGR rate according to various operating states of the engine E is changed.
Is controlled. In Fig. 1, 26, 27 and 28 are EC
A battery as a driving power source of U4, a battery sensor for detecting a battery voltage, and an ignition switch;
These are also connected to ECU4.

As described above, various sensors and controlled devices are connected to the ECU 4, but the hardware of the ECU 4 itself is mainly composed of a CPU (central processing unit) 29 as shown in FIG. . Intake air temperature sensor 7, atmospheric pressure sensor 8, throttle sensor
Data from 11, O ₂ sensor 14 and battery sensor 27 are analog signals, so interface 30 and A / D
It is input to the CPU 29 via the converter 31. The data from the ignition switch 28 is sent via the interface 32, and the data from the crank angle sensor 19, the cylinder discrimination sensor 20 and the air flow meter 6 are directly sent to the CPU 29.
Is input to

The CPU 29 also has a ROM (read-only memory) 33, a RAM (rewrite memory) 34, and a battery 26 via a bus line.
While is connected, data is exchanged with a BURAM (packup memory) 35 in which the stored contents are saved even if the ignition switch 28 is turned off.

Inside the CPU 29, the fuel injection amount, the ignition timing and the opening degree of the EGR valve are determined by using the above various data and memory.
Then, the injector 1 is connected via the injector driver 36, and the power transistor 18 is connected via the ignition drive 37.
The electromagnetic valves 23 are respectively driven via the EGR driver 38.

The operation of the present embodiment will be described below with reference to FIGS. 3 to 7, but the outline of the control in the present embodiment will be briefly described prior to the detailed description.

In this embodiment, first, the target EGR rate is obtained from the measurement result of the operating state measuring means, and the actual EGR rate is obtained from the detection result of the O ₂ sensor. Then, from these deviations, the EGR
Calculates and determines the drive duty ratio of the valve and drives the EGR valve. This calculation is performed on the basis of the valve opening negative pressure specific to the EGR valve (hereinafter, valve opening negative pressure).

On the other hand, learning starts when idle operation continues for 30 seconds. In this case, the oxygen concentration in the intake air is detected by the O ₂ sensor while the drive duty ratio is set to 0 and then gradually increased. Then, when the recirculation of the EGR gas is detected, the valve opening negative pressure of the EGR valve is corrected based on the drive duty ratio at that time.

Thus, unlike the conventional O ₂ sensor output feedback method described above, the present embodiment has a function of learning and correcting the valve opening start driving force (valve opening negative pressure) of the EGR valve, and therefore the responsiveness is improved. As a result, the influence of changes over time is reduced.

The flow of control will be specifically described below with reference to the flowcharts of FIGS. 3 and 4.

When the engine E starts, the EGR control also starts at the same time. The control shown in the flowchart of FIG. 3 is activated by a signal (crank interrupt signal) from the crank angle sensor 19 and is executed for each crank revolution.

When the control is started, the CPU 29 detects the engine speed Ne and the intake air amount A from the output signals of the crank angle sensor 19 and the air flow meter 6, and then calculates the load A / N based on these detection results. Next, the map of the EGR rate (map M1 shown in FIG. 5) stored in the ROM 33 is called, and the target EGR rate (EGR) _{T is} calculated from the rotational speed Ne and the load A / N.
Ask for.

Next, the output voltage I _P of the O ₂ sensor 14 is detected, and this output voltage I _P is corrected by the load A / N. This is because the output characteristic of the O ₂ sensor 14 changes depending on the intake negative pressure (proportional to the load A / N). Next, from the output current value I _P to the actual EGR rate (EGR) _A
Ask for. For calculation, O ₂ sensor 1 when EGR is not performed
An output current value (I _P ) _{0 of 4} is used. (EGR) _A is given by the following equation.

Next, the deviation Ee between the target EGR rate (EGR) _T and the actual EGR rate (EGR) _A is calculated by the following formula.

Ee = (EGR) _T− (EGR) _A (2) Next, the proportional gain K _P for performing proportional control is obtained by the following procedure.

First, the instantaneous proportional gain (K _P ) _CR is calculated from the engine speed Ne and the load A / N using the following formula.

(K _P ) _CR = (K _P ) _IN × f (A / N) × Ne (3) where (K _P ) _IN is the proportional gain base data (fixed value) stored in ROM 33, and f ( A / N) is a correction function.

Next, after comparing the magnitude of this instantaneous proportional gain (K _P ) _CR with the value of the previous instantaneous proportional gain (K _P ) ′ _CR (before one crank revolution), the proportionality is calculated using the calculation formula according to the result. gain
Find K _P.

When (K _P ) _CR ≥ (K _P ) ′ _CR K _P = K _P U × K _P ′ + (1-K _P U) × (K _P ) _CR … (4) (K _P ) _CR <(K _In case of _P ) ' _CR K _P = K _P D × K _P ′ + (1-K _P D) × (K _P ) _CR (5) where K _P U and K _P D are when proportional gain increases And the smoothing coefficient (0 ≦ K _P U <1,0 ≦ K _P D <1) when decreasing
It is a fixed value stored in 33. K _P ′ is the previous proportional gain.

Next, the integral gain K _I for performing integral control is obtained.

First, obtain the instantaneous integral gain (K _I ) _CR using the load A / N by the following equation.

(K _I ) _CR = (K _I ) _IN × f (A / N) (6) where (K _I ) _IN is integral gain base data (fixed value).

Next, this instantaneous integral gain (K _I ) _CR is compared with the previous instantaneous integral gain (K _I ) ′ _IN, and the integral gain K _I is obtained in the same procedure as the proportional gain K _P.

When (K _I ) _CR ≧ (K _I ) ′ _CR K _I = K _I U × K _I ′ ＋ (1-K _I U) × (K _I ) _CR … (7) (K _I ) _CR <(K _In the case of _I ) ' _CR K _I = K _I D × K _I ′ ＋ (1-K _I D) × (K _I ) _CR … (8) where K _I U and K _I D are integrals that are fixed values. Smoothing coefficient when gain increases and decreases (0 ≦ K _I U <1,0 ≦ K _I D <1)
And K _I ′ is the previous integral gain.

Next, from the integration gain K _I and the deviation Ee obtained by the equation (2), the addition data (EGR) used for the integral calculation by the following equation
_{Find I.}

(EGR) _I = K _I × Ee / K1 (9) K1 is a sufficiently large constant to stabilize the control, that is, prevent hunting.

Next, the integration data (EGR) _II is updated using this addition data (EGR) _I.

(EGR) _II = (EGR) ' _II + (EGR) _I (10) where (EGR)' _II is the integrated data up to the previous time.

In addition, the upper and lower limit values of (EGR) _II are set in the calculation of equation (10) so that the value does not go out of the range.

Next, proportional gain K _P , deviation Ee and integral data (EGR)
EGR flow from _II becomes the target serving as a full Eid back data (E
GR) _Ask for _IP .

(EGR) _IP = K _P × Ee + (EGR) _II (11) Next, from this feedback data (EGR) _IP , −2
Calculate the converted flow rate (EGR) _STD at 00 mmHg. This is EGR
This is because the measurement of the flow characteristic of the valve 3 is usually performed by applying a negative pressure of -200 mmHg. (EGR) _STD is exhaust pressure
(. For almost the same as the atmospheric pressure, in the embodiment using the input data of the atmospheric pressure sensor 8) P _exh and the intake pressure P _B (load obtained from the A / N) because the obtained intake pipe negative pressure P _exh - It is given by the following equation using P _B.

Although the intake pressure P _B is obtained from the load A / N in this embodiment, the value of the intake pressure sensor is naturally used when the intake pressure sensor is provided.

Next, in order to secure the converted flow rate (EGR) _STD ,
Find the control negative pressure P _E of the EGR valve 3. The flow rate characteristic of the EGR valve 3 used in the present embodiment is linear with respect to the control negative pressure P _{E as} shown in the map M2 of FIG. Negative pressure) and fully open negative pressure are P _E1 and P _E2 , respectively, and the fully open flow rate is (EGR) _max .

The control negative pressure P _E is given by the following equation.

Here, K2 is a correction coefficient.

Next, the magnitude of P _E and P _E2 is compared. This is because the control negative pressure P _E may become larger than the fully-open negative pressure P _{E2 as} a result of the calculation by the equation (13), and if this is used as it is, the responsiveness at the time of valve closing deteriorates, and (EGR) _STD When ≧ (EGR) _max , P _E = P _E2 (14)

Then, the duty ratio D corresponding to the control negative pressure P _E2 and the negative pressure A / N is searched from the map (map M3) in FIG. 7, and the solenoid valve 23 is driven with this duty ratio D.

If P _E <P _E2 , then the EGR valve 3 is closed ((EG
R) Determine whether _STD = 0). The region where EGR is not performed is an operating region such as idle, full load, high rotation, etc., and is determined from signals from an idle switch (not shown), the air flow meter 6, and the like. Then, when it is not in the closed mode, the duty ratio is searched from the map using P _E obtained by the equation (13), and the solenoid valve 23 is driven.

On the other hand, if it is in the closed mode, it is next determined whether or not it is in the idle operation state. When it is not in the idle operation state, the duty ratio is set to 0%, that is, the driving of the solenoid valve 23 is stopped. When the drive of the solenoid valve 23 is stopped, as shown in the map of FIG. 7, the control negative pressure P _E
Becomes less than the valve opening negative pressure P _E1 , and the valve body of the EGR valve 3 is pressed against the valve seat. The reason for doing this is that the control negative pressure P _E is increased because the pulsating negative pressure in the intake pipe becomes large in operating regions other than idle, that is, at full load and high rotation speed.
_{This is because when E1 is set} , the valve body of the EGR valve 3 causes surging, and unnecessary EGR gas is introduced.

In the idle operation state, an idle learning routine start signal (hereinafter, idle start signal) is transmitted, and the idle learning routine shown in the flowchart of FIG. 4 is started. This routine is started by the main routine shown in FIG. 3, but after starting, it is operated by a timer independent of the main routine. Then, when an operating state other than idle is reached, the processing is stopped at that point. While the idle operation is continued, an idle start signal is transmitted for each crank revolution, but once started, the idle learning routine performs processing regardless of the start signal.

 The processing in the idle learning routine will be described below.

When this routine is started, first the control negative pressure
Let P _E be P _E = P _E1 (15) and search the duty ratio D from the map to set the solenoid valve 23
Drive for 30 seconds. This is because when the pulsation negative pressure of the intake pipe is small, even if the control negative pressure P _E is set as the valve opening load P _E1 , surging does not occur in the valve body of the EGR valve 3, and the response at the time of valve opening is To be enhanced. In addition, driving in this state for 30 seconds is to stabilize the EGR control.

Then, in that state, the duty ratio D after 30 seconds has passed is set to D = 0% (16) and the system stands by for 3 seconds. Then, after that, the output current value I _P of the O ₂ sensor 14 is measured, and the actual EGR rate (EG
R) Calculate _A. Here, the EGR valve 3 waits for 3 seconds.
It takes into consideration the time required for the atmosphere to be introduced into the air and the distance between the EGR valve 3 and the O ₂ sensor 14.

Next, it is determined whether or not the actual EGR rate (EGR) _A is larger than 1%, and if (EGR) _A ≧ 1%, the valve opening negative pressure data P _C is obtained from the map M3. At this time, the criterion of 1% is set in consideration of the accuracy of the O ₂ sensor 14 and the adverse effect of the introduction of EGR gas.

When the valve opening negative pressure data P _C is obtained, the valve opening negative pressure is calculated by the following formula.
Calculate and update P _E1 .

P _E1 = k · P _C + (1-k) P ′ _E1 (17) where P ′ _E1 is the previous valve opening negative pressure, and k is a filter coefficient set to be sufficiently small to prevent hunting. is there.

On the other hand, when (EGR) _A <1%, the solenoid valve is driven for 3 seconds with the duty ratio D set to D = 2% (18). And in this case too
EGR rate (EGR) Determine whether _A is greater than 1%, (EGR)
_{If A} ≧ 1%, the valve opening negative pressure data P _C is obtained, and the valve opening negative pressure P _E is calculated and updated by the equation (17).

(EGR) When _A <1%, the duty ratio D is set to 4
%, Drive the solenoid valve, and judge. And (EG
R) In the case of _A <1%, the duty ratio D is increased by 2% and control / calculation is performed until (EGR) _A ≧ 1%.

The valve opening negative pressure P _E1 thus corrected is used in the equation (13) in the main routine described above, and the accuracy of the EGR control is improved. Also, while the idle learning routine is operating, the main routine performs calculation for each crank revolution, and the EGR control is performed by the main routine from the moment the operating state other than idle is entered.

Above, the description of the present embodiment is finished, but it is needless to say that the present invention is not limited to this embodiment.
The present invention may be applied to an engine having a carburetor instead of I. Further, the recirculation amount detecting means may be other than the O ₂ sensor, and as the EGR valve, one having a higher-order curve flow rate characteristic or one driven by a pulse motor or the like instead of the negative pressure may be used. Good. And when it comes to control,
In the present embodiment, the present invention is applied to the O ₂ sensor output feedback method in which the control negative pressure is calculated based on the valve opening negative pressure, but it may be applied to, for example, an open loop method. Although the calculation method and the calculation procedure in the control are also specifically described in the embodiment, the EGR valve is driven in a sequential manner, and the valve opening driving force is detected by the O ₂ sensor or the like to perform the learning correction. However, it is not necessary to add the duty ratio after setting the duty ratio to 0% as in the embodiment, or to set the waiting time of 30 seconds.

<Effects of the Invention> In the EGR device according to the present invention, since the valve opening driving force that is the reference of the EGR control is learned and corrected, it is optimal regardless of manufacturing error of the EGR valve, aging change of the entire EGR device, and the like. EGR in quantity
Control is performed. As a result, environmental pollution due to harmful exhaust gas is reduced.

[Brief description of drawings]

FIG. 1 and FIG. 2 are a schematic diagram of a centralized control system and a hardware configuration diagram of an electronic control unit, respectively, in one embodiment of the present invention. 3 and 4 are control flowcharts for explaining the operation of the embodiment. FIG. 5 to FIG.
3 is a map of the flow rate characteristic of the EGR rate at the target EGR rate and the duty ratio of the solenoid valve. In the figure, 3 is the EGR valve, the 4 ECU, 14 is the O ₂ sensor 23 is an electromagnetic valve, 33 is ROM, 34 is RAM, 35 is BURAM.

Claims (1)

(57) [Claims] 1. An exhaust gas recirculation apparatus for reducing nitrogen oxide concentration in exhaust gas by introducing a part of exhaust gas of the internal combustion engine into an intake system to lower combustion temperature. An operating state measuring means for measuring the operating state, a recirculation amount control valve provided in the exhaust gas recirculation passage for increasing and decreasing the recirculation amount by opening and closing the passage, and a control valve for driving this recirculation amount control valve. A drive unit, a gas concentration detector for detecting the exhaust gas recirculation amount, a target exhaust gas recirculation amount is determined based on the measurement result of the operating state measuring unit, and the target exhaust gas recirculation amount is determined. While controlling the opening and closing of the recirculation amount control valve using the control valve drive means so that the valve opening amount according to the circulation amount becomes, the state in which exhaust gas recirculation determined by the operating conditions of the internal combustion engine is not performed is a certain time. When you continue, The control valve drive means is used to apply a gradual driving force to the recirculation amount control valve, and the exhaust gas recirculation start timing is detected by the gas concentration detector, thereby opening the recirculation amount control valve. An exhaust gas recirculation device, comprising: a control unit that learns and corrects valve start driving force data.