JPH08170539A - Supercharged type internal combustion engine with exhaust gas reflux control device - Google Patents

Abstract

PURPOSE: To reflux exhaust gas while a turbine is positively driven, return an exhaust gas under reduced temperature, and facilitate the supply of sufficient amount of air into engine by returning exhaust gas to an intake passage after a turbine of a supercharger is driven. CONSTITUTION: In a supercharger 4 of an internal combustion engine, an air- supplying cooler 10 and a bypass passage 11 bypassing the cooler 10 are provided on the downstream side of a compressor 6 in an intake passage 2 to switch the flow of intake to either of the cooler 10 side and the bypass passage 11 side by a change-over valve 12. Then, the downstream side of a turbine 5 and the upstream side of the compressor 6 are communicated with each other by a connection passage 8, and the connection passage 8 is opened or closed by an opening/closing valve 9. In this case, when the internal combustion engine is in a specified operating range on the basis of detected information of operating condition detecting means 21 to 23, exhaust gas is returned through the connection passage 8 to the intake passage 2, and the bypass passage 11 is controlled to be opened by switching the change-over valve 12.

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 capable of controlling recirculation of exhaust gas through an exhaust gas recirculation passage and supercharging by a supercharger, and particularly, an exhaust gas suitable for use in a supercharged diesel engine. The present invention relates to a supercharged internal combustion engine with a gas recirculation control device.

[0002]

2. Description of the Related Art FIG. 29 is a schematic diagram showing an intake / exhaust route of a supercharged diesel engine with an exhaust gas recirculation passage used in a conventional automobile. In FIG. 29, 1 is a diesel engine main body (hereinafter referred to as engine Yes) 2
Is an intake passage, and 3 is an exhaust passage. 4 is a supercharger (hereinafter,
It is a turbocharger), and rotates a compressor 6 installed in an intake passage 2 through a turbine 5 installed in an exhaust passage 3 to send compressed air to an engine 1.

An exhaust gas recirculation device (EGR) 7 is composed of an exhaust gas recirculation passage 28 and an opening / closing valve 29. The exhaust gas recirculation passage 28 is the exhaust passage 3 here.
Is arranged so that the upstream side of the turbine 5 and the downstream side of the compressor 6 in the intake passage 2 can communicate with each other. Further, the opening / closing valve 29 is the exhaust gas recirculation passage 28.
Is intervened in the middle of.

Further, 10 is an air supply cooler (intercooler), which is provided downstream of the compressor 6 in the intake passage 2 and is supercharged by the turbocharger 4. Cool the supply air. By the way, the exhaust gas recirculation passage 28 is provided with NO _X in the exhaust gas.
It is intended to suppress the occurrence. That is, NO _X
Since the occurrence of is low if the combustion temperature of the engine is low, the exhaust gas is recirculated to the intake side to reduce the exhaust gas concentration in the intake air, and thereby the combustion temperature is lowered.
It is intended to suppress the generation of NO _X in the exhaust gas.

Therefore, exhaust gas recirculation is unnecessary if the combustion temperature is low. Further, since the recirculation of exhaust gas is rather a hindrance in increasing the engine output, it is desirable to stop the recirculation of exhaust gas even when the combustion temperature is high and a large engine output is required. In particular,
In a vehicle engine, unlike a stationary engine, it is not always necessary to reduce NO _{X in} exhaust gas when the engine is operating, but NO _X may be appropriately reduced according to the operating state of the engine.

Therefore, the on-off valve 29 provided in the exhaust gas recirculation passage 28 is controlled by the electronic control unit (ECU) 13 so that the exhaust gas is appropriately recirculated in response to each of the above demands. The opening degree is adjusted according to the operating state of the engine 1. As the operating state of the engine 1, generally, the engine speed, the accelerator opening degree, and the cooling water temperature of the engine are used. Based on these detection data, the on-off valve 29 is controlled as follows.

For example, if the cooling water temperature of the engine is low, it can be judged that the combustion temperature is still low, and NO _x in the exhaust gas is
The emission of exhaust gas is small, and exhaust gas recirculation is not necessary or even a small amount thereof is sufficient. Therefore, if the cooling water temperature of the engine is equal to or lower than the predetermined value, the on-off valve 29 is closed, and if the cooling water temperature is equal to or higher than the predetermined value, the on-off valve 29 is opened at an opening degree corresponding to the cooling water temperature. On the other hand, when a large engine output is required, that is, during high speed operation or high load operation, the on-off valve 2 is irrelevant regardless of the cooling water temperature.
9 is closed to stop the exhaust gas recirculation. Whether it is a high speed operation or a high load operation can be determined based on the engine speed or the accelerator opening. Specifically, if the engine speed or the accelerator opening exceeds a predetermined range, the higher the The on-off valve 29 is closed, and the on-off valve 29 is closed in a region where the engine speed and the accelerator opening are sufficiently high.

In the supercharged diesel engine with an exhaust gas recirculation passage constructed as described above, in the turbocharger 4, a portion of the exhaust energy is recovered as rotational energy by the turbine 5 while supercharging through the compressor 6. On the other hand, in the exhaust gas recirculation passage 28, the exhaust gas is recirculated to the intake side to reduce the exhaust gas concentration in the intake air, thereby lowering the combustion temperature and lowering the exhaust gas temperature. , N in the exhaust gas
O _X to suppress the occurrence.

[0009]

By the way, although the turbocharger 4 supercharges in accordance with the pressure of the exhaust gas,
When the engine 1 is operating at high speed or high load, the exhaust energy is large, so sufficient supercharging can be performed. Few. In particular, during acceleration from such low speed or low load operation, so-called turbo lag occurs and the supercharging effect hardly appears.

On the other hand, when the exhaust gas recirculation passage 28 is opened, a part of the exhaust energy that should flow into the turbine 5 will be recirculated through the exhaust gas recirculation passage 28 before flowing into the turbine 5, and that much, The boost pressure will decrease. Further, if the combustion temperature is low, the particulate matter (diesel particulate) is likely to increase. Since the exhaust gas recirculation passage 28 is closed during high-speed operation or high-load operation, there is no problem, but in other cases, that is, except during high-speed operation / high-load operation, supercharging by the turbocharger 4 is originally required. In addition to the low pressure, the exhaust gas recirculation further reduces the supercharging pressure, resulting in a reduction in engine output. In particular, when an acceleration operation is attempted from a low speed operation or a low load operation, the exhaust gas recirculation has a great influence, and the supercharging pressure does not increase easily and it takes time to increase the output of the engine. Also, the particulate matter will increase.

Japanese Unexamined Patent Publication No. 4-47156 and Japanese Unexamined Patent Publication No. 4-47156
Japanese Patent No. 103867 discloses a structure in which an introduction passage for exhaust gas recirculation is provided in a portion of the exhaust passage on the downstream side of the turbine of the turbocharger. In this way, when the exhaust gas is recirculated from the downstream side of the turbine, the exhaust gas with energy before being recirculated flows into the turbine, so that it is possible to suppress the decrease in the supercharging pressure.

By the way, when the exhaust gas recirculation inlet is provided on the downstream side of the turbine as described above, the exhaust gas recirculation outlet (that is, the connecting portion of the exhaust gas recirculation passage to the air supply passage) is more than the compressor of the turbocharger. It is generally installed on the upstream side. Of course, as disclosed in JP-A-4-47156, a structure in which the connecting portion of the exhaust gas recirculation passage to the air supply passage is provided on the downstream side of the compressor of the turbocharger is also conceivable, but the exhaust gas recirculation inlet If the exhaust gas recirculation outlet is provided on the rear flow side of the turbine while being provided on the rear flow side of the turbine, the exhaust gas recirculation passage tends to be complicated. Therefore, when the exhaust gas recirculation inlet is provided on the downstream side of the turbine, the exhaust gas recirculation outlet is generally provided on the upstream side of the compressor of the turbocharger.

However, when an intercooler is provided in the intake passage, this intercooler is provided on the downstream side of the compressor. Therefore, if the exhaust gas recirculation outlet is provided on the upstream side of the compressor of the turbocharger, it goes without saying that the recirculated exhaust gas is exhausted. Gas will flow into the intercooler. Since this exhaust gas contains particulate matter, when the recirculated exhaust gas flows into the intercooler, the particulate matter matter is intercooled by the intercooler 1.
There is a problem that it adheres to the inside of 0 to contaminate the inside of the intercooler 10 or cause clogging.

The present invention was devised in view of the above problems, and in an internal combustion engine equipped with a supercharger, an exhaust gas recirculation passage, and a charge air cooler, NOx by exhaust gas recirculation.
Exhaust gas recirculation, which has a reduction effect and can reliably increase the output of the internal combustion engine by a supercharger when acceleration is required, and can prevent the occurrence of contamination and clogging in the supply air cooler due to exhaust gas recirculation. An object of the present invention is to provide a supercharged internal combustion engine with a control device.

[0015]

Therefore, a supercharged internal combustion engine with an exhaust gas recirculation control system according to the present invention is a turbine provided in an exhaust passage of an internal combustion engine and driven by a flow of exhaust gas. And a supercharger that is provided in the intake passage of the internal combustion engine and that is driven by the turbine, and cools the supply air that is provided downstream of the compressor in the intake passage and that is supercharged by the compressor. A supply air cooler and one end connected to a part of the intake passage upstream of the cooler and the other end connected to a part of the intake passage downstream of the cooler to bypass the cooler. A bypass passage, a switching valve that is provided at a branch portion between the bypass passage and the intake passage, and switches the intake air to either the cooler side or the bypass passage side; An operating state detecting means for detecting an operating state of the engine; an exhaust gas recirculation passage having a connecting passage connecting the downstream side of the turbine in the exhaust passage and the upstream side of the compressor in the intake passage; An on-off valve that opens and closes the passage, and controls the opening and closing of the on-off valve so that the connection passage recirculates exhaust gas when the internal combustion engine is in a predetermined operating region based on detection information from the operating state detection means. At the same time, it is characterized by comprising control means for controlling the switching valve so that the bypass passage side is opened when the connection passage is opened.

According to a second aspect of the present invention, there is provided the supercharged internal combustion engine with an exhaust gas recirculation control device according to the first aspect, wherein the control means is configured to perform the operation based on detection information from the operating state detection means. When the internal combustion engine is in an operating region other than the predetermined operating region, the on-off valve is closed to stop the recirculation of the exhaust gas, and the switching valve is turned on after a predetermined period has elapsed from the closing of the on-off valve. The feature is that the cooler side is controlled to be opened.

According to a third aspect of the present invention, in the supercharged internal combustion engine with an exhaust gas recirculation control device according to the first or second aspect, the control means is based on detection information from the operating state detection means. When the internal combustion engine is decelerating, the opening / closing of the on-off valve is controlled so as to correct the exhaust gas recirculation amount to the reduction amount side. A supercharged internal combustion engine with an exhaust gas recirculation control device according to a fourth aspect of the present invention has the configuration according to the third aspect, wherein the operating state detecting means artificially operates the internal combustion engine. Which has an accelerator opening detection means for detecting the internal combustion engine, when the control means, based on the detection information from the accelerator opening detection means, reduces the accelerator opening rate at a preset value or more. The feature is that the engine is judged to be decelerating.

A supercharged internal combustion engine with an exhaust gas recirculation control device according to a fifth aspect of the present invention is the supercharged internal combustion engine according to the third aspect, wherein the operating state detecting means detects a rotational speed of the internal combustion engine. The internal combustion engine is decelerating when the control means has a detection means and the reduction speed of the rotation speed of the internal combustion engine is equal to or greater than a preset value based on the detection information from the rotation speed detection means. It is characterized by determining that there is.

According to a sixth aspect of the present invention, there is provided a supercharged internal combustion engine with an exhaust gas recirculation control device according to the first aspect, wherein the exhaust gas recirculation passage is located downstream of the turbine in the exhaust passage. A first connection passage connecting the intake passage to the upstream side of the compressor, and a second connection passage connecting the exhaust passage to the upstream side of the turbine and the intake passage to the downstream side of the intake cooler. And a second opening / closing valve for opening / closing the second connecting passage together with a first opening / closing valve for opening / closing the first connecting passage.

According to a seventh aspect of the present invention, there is provided the supercharged internal combustion engine with an exhaust gas recirculation control device according to the sixth aspect, wherein the control means is based on the detection information from the operating state detection means. When the internal combustion engine is accelerating in the above predetermined operating range, the first opening / closing valve is opened and the second opening / closing valve is closed, and the switching valve is controlled to be in a state in which the bypass passage side is opened. When the internal combustion engine has finished accelerating in the predetermined operating range based on the detection information from the operating state detecting means, the first opening / closing valve is closed and the second opening / closing valve is opened, and It is characterized in that the switching valve is controlled so that the cooler side is opened.

The supercharged internal combustion engine with an exhaust gas recirculation control device of the present invention according to claim 8 is the structure according to claim 7, wherein the operating state detecting means is for artificially operating the internal combustion engine. An accelerator opening detection means for detecting an accelerator opening is provided, and the control means, based on the detection information from the accelerator opening detection means, the increase rate of the accelerator opening is a preset opening increase rate. When it becomes equal to or more than the set value, it is determined that the internal combustion engine has started acceleration, and thereafter, when the accelerator opening becomes equal to or less than a preset opening setting value, it is determined that the internal combustion engine has finished acceleration. It is characterized by that.

A supercharged internal combustion engine with an exhaust gas recirculation control device according to a ninth aspect of the present invention is the structure according to the seventh aspect, wherein the internal combustion engine is mounted on a vehicle, and the operating state detecting means is provided on the vehicle. The speed detecting means for detecting the speed of, the control means, based on the detection information from the speed detecting means,
It is determined that the internal combustion engine is accelerating when the increasing speed of the vehicle speed is equal to or more than a preset first increasing speed set value, and thereafter, the increasing speed of the vehicle speed is increased by the first increasing speed setting value. It is characterized in that it is judged that the internal combustion engine has finished acceleration when the value becomes equal to or smaller than a second increased speed set value that is set in advance as a value smaller than the increased speed set value.

According to a tenth aspect of the present invention, there is provided the supercharged internal combustion engine with an exhaust gas recirculation control device according to the seventh aspect, wherein the operating state detecting means detects the supercharging pressure. The control means is accelerating the internal combustion engine when the increasing speed of the supercharging pressure is equal to or higher than a preset first set value based on the detection information from the supercharging pressure detecting means. It is determined that the internal combustion engine has finished accelerating when the supercharging pressure becomes equal to or less than a second preset value preset as a value smaller than the first preset value. It has a feature.

According to an eleventh aspect of the present invention, there is provided a supercharged internal combustion engine with an exhaust gas recirculation control device according to the seventh aspect, wherein the operating state detecting means detects a rotational speed of the internal combustion engine. The control means has a detection means, and after the acceleration determination of the internal combustion engine, the increase speed of the rotation speed of the internal combustion engine is equal to or less than a preset set value based on the detection information from the rotation speed detection means. When it becomes, it is characterized that it is judged that the internal combustion engine has finished acceleration.

According to a twelfth aspect of the present invention, there is provided a supercharged internal combustion engine with an exhaust gas recirculation control device according to any one of the first to eleventh aspects, wherein one of the intake passage and the exhaust passage is provided. A passage throttling means for narrowing the passage area is provided, and the control means controls opening / closing of the passage throttling means in order to control the exhaust gas recirculation amount. According to a thirteenth aspect of the present invention, in the supercharged internal combustion engine with an exhaust gas recirculation control device according to the twelfth aspect, the passage throttle means is located upstream of a connection portion of the intake passage with the connection passage. It is characterized by having an intake throttle valve provided in the.

A supercharged internal combustion engine with an exhaust gas recirculation control device according to a fourteenth aspect of the present invention is the structure according to the thirteenth aspect, wherein the intake passage is provided in a portion of the intake passage upstream of the compressor. It is characterized in that it has a pressure detection means for detecting the internal pressure, and the control means controls the opening and closing of the intake throttle valve in order to control the exhaust gas recirculation amount according to the detection information of the pressure detection means. .

According to a fifteenth aspect of the present invention, in the supercharged internal combustion engine with an exhaust gas recirculation control device according to the twelfth aspect, the passage throttle means is formed from a connecting portion of the intake passage with the connecting passage. Is equipped with an exhaust throttle valve provided on the downstream side. According to a sixteenth aspect of the present invention, in the supercharged internal combustion engine with an exhaust gas recirculation control device according to the fifteenth aspect, the exhaust passage is provided in a portion of the exhaust passage downstream of the exhaust turbine. It is characterized in that it has a pressure detecting means for detecting the pressure, and the control means controls the opening and closing of the intake throttle valve to control the exhaust gas recirculation amount according to the detection information of the pressure detecting means.

A supercharged internal combustion engine with an exhaust gas recirculation control device according to a seventeenth aspect of the present invention has the structure according to any one of the first to sixteenth aspects, wherein the exhaust gas recirculation passage is connected to the connecting passage with an exhaust gas. An exhaust gas cooling means for cooling the gas is interposed. The supercharged internal combustion engine with an exhaust gas recirculation control device of the present invention according to claim 18 is the structure according to any one of claims 1 to 17, wherein the connection passage of the exhaust gas recirculation passage is provided with an exhaust gas inside the exhaust gas. It is characterized in that a filter for collecting particulate matter is interposed.

[0029]

In the supercharged internal combustion engine with the exhaust gas recirculation control device according to the first aspect of the present invention, the turbine provided in the exhaust passage is driven by the flow of the exhaust gas during operation of the internal combustion engine, and the intake passage By driving the compressor provided in the, the supercharging pressure is applied to the intake air flow in the intake passage, and supercharging is performed by the supercharger.

At this time, the operating state of the internal combustion engine is detected by the operating state detecting means, and the control means controls the switching valve and the on-off valve to cool the supply air by the supply air cooler and recirculate the exhaust gas. It controls the flow of exhaust gas through the passage. That is, in the control means, based on the detection information from the operating state detection means, when the internal combustion engine is in the predetermined operating region, the connection passage forming the exhaust gas recirculation passage recirculates the exhaust gas. Is controlled so that the switching valve is opened to the bypass passage side when the connection passage is opened.

As a result, when the internal combustion engine is in the predetermined operating range, the exhaust gas recirculates to the intake passage side, and NOx in the exhaust gas is reduced. In particular, since the exhaust gas recirculation passage is constituted by a connection passage that guides the exhaust gas from the downstream side of the turbine in the exhaust passage to the upstream side of the compressor in the intake passage, the exhaust gas after driving the turbine is exhausted. The gas is recirculated to the intake passage. Therefore, the exhaust gas can be recirculated while the turbine is reliably driven by fully utilizing the energy of the exhaust gas. Therefore, the supercharging pressure can be secured and the advantages of the supercharger can be fully utilized.

Further, since the temperature of the exhaust gas after driving the turbine is lowered, the exhaust gas having a lowered temperature is recirculated to the intake passage. By ensuring the recirculation of the exhaust gas having such a low temperature and the supercharging pressure, the equivalence ratio between the fresh air and the recirculation exhaust gas in the intake passage increases, and a sufficient amount of air is easily supplied to the engine. The combustion of the engine is more likely to be performed in a complete combustion state, the output of the engine is secured, and the generation of particulate matter due to the combustion is suppressed.

Along with this, the intake air passes through the bypass passage side bypassing the cooler, but the intake gas bypasses the cooler in this way, so that the exhaust gas does not flow through the cooler. Clogging and damage of the cooler are prevented. That is, the exhaust gas recirculation passage is constituted by a connection passage that guides the exhaust gas from the downstream side of the turbine in the exhaust passage to the upstream side of the compressor in the intake passage. Particulate matter contained in the exhaust gas is mixed in.
The cooler normally has a narrow flow passage to ensure cooling performance, and is likely to be clogged with particulate matter in the exhaust gas, but when exhaust gas recirculates, intake air containing particulate matter is Since the bypass is bypassed to the cooler, clogging of the cooler is avoided.

In the supercharged internal combustion engine with an exhaust gas recirculation control device according to the present invention as set forth in claim 2, the control means causes the internal combustion engine to perform the predetermined operation based on the detection information from the operating state detection means. When it is in an operating region other than the operating region, the on-off valve is closed to stop the recirculation of the exhaust gas. As a result, although NOx in the exhaust gas is not reduced, the output reduction of the engine and the generation of particulate matter in the exhaust gas caused by the exhaust gas recirculation are suppressed.

When the on-off valve is closed, the switching valve is controlled to open on the cooler side after a lapse of a predetermined period from the time of closing the on-off valve. It is possible to shift to the state in which the cooler is used while surely avoiding the inclusion of particulate matter in the gas into the intake air, and after opening the cooler side, while cooling the intake air through the cooler, charging the intake air Increase efficiency and improve engine output.

In the supercharged internal combustion engine with exhaust gas recirculation control device according to the third aspect of the present invention, the internal combustion engine is being decelerated by the control means based on the detection information from the operating state detection means. At some time, the opening / closing of the on-off valve is controlled so as to correct the exhaust gas recirculation amount to the reduction amount side.
That is, during deceleration of the internal combustion engine, the recirculation of exhaust gas increases the amount of air required for combustion, resulting in a decrease in the excess air ratio. Therefore, when the vehicle is decelerated and then re-accelerated or the deceleration is changed to the steady operation, the excess air ratio is further reduced, and the particulate matter in the exhaust gas is increased.

On the other hand, in the present device, the recirculation amount of the exhaust gas is reduced during deceleration, and therefore the excess air ratio does not decrease even during deceleration, and deceleration re-accelerates or deceleration shifts to steady operation. Even if it does, the excess air ratio is sufficiently secured, and the increase of particulate matter in the exhaust gas is suppressed. In the supercharged internal combustion engine with an exhaust gas recirculation control device according to the fourth aspect of the present invention, the control means presets a reduction rate of the accelerator opening based on the detection information from the accelerator opening detection means. Since it is determined that the internal combustion engine is decelerating when it is equal to or greater than the set value, it is easy to detect the deceleration of the internal combustion engine at the initial stage of reducing the accelerator opening, and the exhaust gas recirculation amount can be quickly reduced from the deceleration start time. Can be executed, and when deceleration is re-accelerated or deceleration is changed to steady operation, the increase of particulate matter in the exhaust gas is reliably suppressed.

In the supercharged internal combustion engine with exhaust gas recirculation control device according to the fifth aspect of the present invention, the control means determines the rotational speed of the internal combustion engine based on the detection information from the rotational speed detection means. Since it is determined that the internal combustion engine is decelerating when the decrease speed is equal to or greater than a preset set value, it is easy to reliably detect the deceleration, and it is possible to reliably execute the exhaust gas recirculation amount reduction control during deceleration. When deceleration is re-accelerated or deceleration is changed to steady operation, the increase of particulate matter in the exhaust gas is reliably suppressed.

In the supercharged internal combustion engine with the exhaust gas recirculation control device according to the sixth aspect of the present invention, the first connection passage and the second connection passage can be selectively used as the exhaust gas recirculation passage. The first connection passage is opened / closed by the first opening / closing valve, and the second connection passage is opened / closed by the second opening / closing valve.
The first connection passage connects the exhaust passage with the downstream side of the turbine and the intake passage with the upstream side of the compressor. Therefore, when the exhaust gas is recirculated using the first connection passage, the exhaust gas is exhausted. The exhaust gas after driving the turbine in the passage is recirculated to the intake side. Therefore, while the exhaust gas is being recirculated, the turbine is surely driven by the exhaust gas, and the exhaust gas can be recirculated without lowering the boost pressure by the supercharger.

On the other hand, the second connecting passage connects the upstream side of the turbine in the exhaust passage and the downstream side of the intake cooler in the intake passage. When the gas is recirculated, the high-temperature exhaust gas recirculates to the intake passage without flowing through the intake cooler and the compressor on the upstream side of the intake cooler. However, the heat effect of the exhaust gas does not occur on the compressor.

In the supercharged internal combustion engine with an exhaust gas recirculation control device according to the seventh aspect of the present invention, the control means controls the first open / close valve and the second open / close valve based on the detection information from the operating state detection means. Control the valve and the switching valve. That is, when the internal combustion engine is accelerating in the predetermined operating range, the first opening / closing valve is opened, the second opening / closing valve is closed, and the switching valve is opened on the bypass passage side. To control. As a result, the supercharging pressure is secured while the exhaust gas is recirculated, and NOx reduction due to exhaust gas recirculation and securing of engine output due to supercharging and reduction of particulate matter in the exhaust gas are both achieved. You can Further, since the bypass passage side is opened, even if particulate matter is contained in the exhaust gas recirculated to the intake passage side, this particulate matter will not enter the cooling machine, and the particulate matter will contaminate the cooling machine. And clogging can be avoided.

On the other hand, when the internal combustion engine has finished accelerating in the above predetermined operating range, the first opening / closing valve is closed and the second opening / closing valve is opened, and the switching valve is connected to the cooler side. Control to open state. As a result, the high-temperature exhaust gas recirculates to the intake passage without flowing through the compressor, and the exhaust gas can recirculate without affecting the heat of the exhaust gas to the compressor. It is possible to reduce NOx in the gas.

In the supercharged internal combustion engine with an exhaust gas recirculation control device according to the present invention as set forth in claim 8, the control means increases the accelerator opening based on the detection information from the accelerator opening detecting means. When the speed becomes equal to or higher than a preset increase speed setting value, it is determined that the internal combustion engine has started acceleration, and thereafter, when the accelerator opening becomes equal to or lower than a preset opening setting value, the internal combustion engine is Judge that the acceleration is completed.

Since the accelerator opening detected by the accelerator opening detecting means is for artificially operating the internal combustion engine, if the acceleration start or the acceleration end of the internal combustion engine is judged based on the accelerator opening. , The start of acceleration is determined when the internal combustion engine is about to start acceleration, and the end of acceleration is determined when the internal combustion engine is about to end acceleration. . In particular, by determining the acceleration start of the internal combustion engine from the increasing speed of the accelerator opening, it is possible to determine the acceleration start of the internal combustion engine in the initial stage of the acceleration start command. Therefore, the control of the first opening / closing valve, the second opening / closing valve, and the switching valve can be swiftly transitioned to the state of acceleration control at the start of acceleration, and quickly from the state of such acceleration control to the state of normal control at the end of acceleration. Can be restored.

In the supercharged internal combustion engine with an exhaust gas recirculation control device according to the present invention as set forth in claim 9, the speed detecting means detects the speed of the vehicle, and the control means detects the speed from the speed detecting means. Based on the information, it is determined that the internal combustion engine is accelerating when the speed increase rate of the vehicle is equal to or higher than a preset first increase speed set value, and thereafter, the speed increase rate of the vehicle is When it becomes less than or equal to a second increase speed setting value that is set in advance as a value smaller than the first increase speed setting value, it is determined that the internal combustion engine has finished acceleration.

Increase in vehicle speed Since the accelerator opening detected by the accelerator opening detecting means is for artificially operating the internal combustion engine, the acceleration start of the internal combustion engine is started based on this accelerator opening. When the internal combustion engine is about to start acceleration, the start of acceleration is determined, and when the internal combustion engine is about to end acceleration, the end of acceleration is determined. Will be judged. Therefore, the control of the first opening / closing valve, the second opening / closing valve, and the switching valve can be swiftly transitioned to the state of acceleration control at the start of acceleration, and quickly from the state of such acceleration control to the state of normal control at the end of acceleration. Can be restored.

In the supercharged internal combustion engine with the exhaust gas recirculation control device according to the tenth aspect of the present invention, the control means is:
Based on the detection information from the supercharging pressure detecting means, it is determined that the internal combustion engine is accelerating when the increasing speed of the supercharging pressure is equal to or higher than a preset first set value. Supply pressure
The second preset value that is smaller than the first set value
When it becomes less than the set value, it is judged that the internal combustion engine has finished the acceleration. Acceleration of the internal combustion engine results in increased intake and increased exhaust, increasing supercharging pressure. Therefore, during acceleration of the engine, intake air and exhaust gas also increase at a certain speed or more, and supercharging pressure also increases at a certain speed or more. Therefore, it can be reliably determined that the internal combustion engine is accelerating based on the increasing speed of the boost pressure.

In the supercharged internal combustion engine with the exhaust gas recirculation control device according to the present invention as set forth in claim 11, the control means comprises:
After the acceleration determination of the internal combustion engine, the internal combustion engine ends the acceleration when the increase speed of the rotation speed of the internal combustion engine becomes equal to or less than a preset set value based on the detection information from the rotation speed detection means. To judge. Thus, by directly using the rotation speed of the internal combustion engine, it is possible to reliably determine the end of acceleration of the internal combustion engine.

In the supercharged internal combustion engine with the exhaust gas recirculation control device according to the present invention as set forth in claim 12, the control means is:
The passage throttling means is opened / closed to control the exhaust gas recirculation amount. In this way, when the passage area of one of the intake passage and the exhaust passage is reduced by the passage throttle means,
The amount of exhaust gas recirculated to the intake side can be increased,
The reduction of NOx in the exhaust gas is promoted.

In the above-mentioned supercharged internal combustion engine with exhaust gas recirculation control device according to the present invention, the intake throttle valve is provided on the upstream side of the connection portion of the intake passage with the connection passage. Therefore, when the intake throttle valve is throttled, the introduction of fresh air to the intake side is suppressed, so that the recirculation amount of exhaust gas to the intake side can be increased and the reduction of NOx in the exhaust gas is promoted. .. In particular, when the exhaust gas recirculation passage is composed of a connection passage that connects a downstream side of the exhaust passage with respect to the turbine and an upstream side of the intake passage with respect to the compressor, the pressure (back pressure) of the turbine is reduced. ) And the pressure (atmospheric pressure) upstream of the compressor are reduced, and the exhaust gas recirculation amount tends to decrease, but it is possible to obtain a sufficient exhaust gas recirculation amount by throttling the intake throttle valve. Become.

In the supercharged internal combustion engine with an exhaust gas recirculation control device according to claim 14 of the present invention, the pressure detecting means detects the pressure inside the intake passage upstream of the compressor, Since the control means controls the opening and closing of the intake throttle valve to control the exhaust gas recirculation amount according to the detection information of the pressure detection means, it is possible to perform the appropriate exhaust gas recirculation according to the pressure state. .

In the above-mentioned supercharged internal combustion engine with exhaust gas recirculation control device according to the present invention, the exhaust throttle valve is provided on the downstream side of the connection portion of the intake passage with the connection passage. Therefore, when the exhaust throttle valve is throttled, the exhaust pressure of the exhaust intake portion of the connection passage increases, so that the differential pressure between the upstream side (exhaust passage side) and the downstream side (intake passage side) of the connection passage increases. Then, the amount of exhaust gas recirculated to the intake side can be increased, and the reduction of NOx in the exhaust gas is promoted. In particular, when the exhaust gas recirculation passage is composed of a connection passage that connects a downstream side of the exhaust passage with respect to the turbine and an upstream side of the intake passage with respect to the compressor, pressure downstream of the turbine (back pressure ) And the pressure (atmospheric pressure) upstream of the compressor are reduced, and the exhaust gas recirculation amount tends to decrease. However, by throttling the exhaust throttle valve, the differential pressure can be increased and sufficient exhaust gas can be obtained. The reflux amount can be obtained.

In the above-mentioned supercharged internal combustion engine with exhaust gas recirculation control device according to the present invention, the pressure detecting means detects the pressure inside the exhaust passage downstream of the exhaust turbine. Since the control means controls the opening / closing of the exhaust throttle valve to control the exhaust gas recirculation amount according to the detection information of the pressure detection means, it is possible to perform the appropriate exhaust gas recirculation according to the pressure state. Become.

In the above-mentioned supercharged internal combustion engine with an exhaust gas recirculation control device according to a seventeenth aspect of the present invention, the exhaust gas cooling means interposed in the connection passage of the exhaust gas recirculation passage is the exhaust gas recirculation means. Since it cools the exhaust gas passing through the passage,
The temperature of the exhaust gas recirculating to the intake passage decreases. Thus, even in the configuration in which the exhaust gas recirculation passage is connected to the upstream side of the compressor in the intake passage and the recirculation exhaust gas flows into the compressor, it is possible to avoid exhaust gas from heating the compressor while recirculating the exhaust gas.

In the above-mentioned supercharged internal combustion engine with exhaust gas recirculation control device of the present invention according to claim 18, the filter interposed in the connection passage of the exhaust gas recirculation passage has a particulate matter in the exhaust gas. To collect. Therefore, the particulate matter in the recirculated exhaust gas is removed, and the connection portion of the connection passage to the intake passage is arranged on the upstream side of the air supply cooler so that the recirculated exhaust gas is replenished. Even in the case of flowing through the inside of the air supply cooler, the inside of the air supply cooler is prevented from being contaminated with particulate matter.

[0056]

Embodiments of the present invention will be described below with reference to the drawings. First, a supercharged internal combustion engine with an exhaust gas recirculation control device according to the first embodiment will be described. FIG. 1 is a schematic diagram showing an intake / exhaust route of the engine. The supercharged internal combustion engine according to the present embodiment is a supercharged diesel engine and is installed in an automobile.

In FIG. 1, the same symbols as those in FIG. 29 indicate the same things. That is, 1 is a diesel engine main body (hereinafter abbreviated as engine), 2 is an intake passage, and 3 is an exhaust passage. Reference numeral 4 denotes a supercharger (hereinafter referred to as a turbocharger), which feeds compressed air to the engine 1 by rotating a compressor 6 installed in an intake passage 2 through a turbine 5 installed in an exhaust passage 3. It is supposed to do.

An exhaust gas recirculation device (EGR system) 7 is composed of an exhaust gas recirculation passage (connection passage) 8 and an opening / closing valve (EGR valve) 9. The exhaust gas recirculation passage 8 is arranged here so that the downstream side of the turbine 5 in the exhaust passage 3 and the upstream side of the compressor 6 in the intake passage 2 can communicate with each other. In this way, the exhaust gas recirculation passage 8 is provided for the turbine 5
By recirculating the exhaust gas after driving the engine to the intake passage 2, the energy of the exhaust gas is fully utilized so that the exhaust gas can be recirculated while reliably driving the turbine. It is intended to secure supercharging pressure. Further, since the temperature of the exhaust gas after driving the turbine 5 is lowered, the exhaust gas having a lower temperature is recirculated to the intake passage 2, so that the recirculation of the exhaust gas having a lower temperature and the supercharging pressure are reduced. By ensuring this, the equivalence ratio of the fresh air and the recirculated exhaust gas can be increased in the intake passage 2, and a sufficient amount of air can be supplied into the engine. As a result, even when exhaust gas recirculates, combustion of the engine can be performed in a more complete combustion state, and it is expected that NOx can be reduced, the output of the engine can be secured, and the occurrence of particulate matter due to combustion can be suppressed.

The on-off valve 9 is interposed in the exhaust gas recirculation passage 8 so that the opening (valve lift amount) can be adjusted. Further, 10 is a cooler for air supply (hereinafter referred to as an intercooler), and this intercooler 10 is provided in the intake passage 2 downstream of the compressor 6, and supplies the air supercharged by the turbocharger 4. Cooling.

In this device, the bypass passage 11 that bypasses the intercooler 10 and supplies intake air to the engine 1 is provided.
Is provided, and the intake passage 2 to the bypass passage 1
In the part branched to 1, the mode in which only the intake passage 2 side equipped with the intercooler 10 is opened, and the bypass passage 11
A switching valve 12 is provided that can selectively switch between a mode in which only the side is opened.

The open / close valve 9 and the switching valve 11 provided in the exhaust gas recirculation passage 8 are electronic control units (hereinafter referred to as ECs) as control means according to the operating state of the engine 1.
U) 13. As the operating state of the engine 1, the engine speed Ne, the accelerator opening APS, and the engine coolant temperature WT are generally used. EC
In U13, although not shown, detection signals from the engine speed sensor 21, the accelerator opening sensor (accelerator opening detecting means) 22 and the water temperature sensor 23 as the operating state detecting means of the engine 1 are not fetched at a predetermined cycle. , The on-off valve 9 and the switching valve 12 based on these detection data
Is controlled as follows.

That is, the purpose of the exhaust gas recirculation is to reduce the combustion temperature of the engine by exhaust gas recirculation to suppress the generation of NO _{X in} the exhaust gas. When the combustion temperature of the engine is low, since the generation amount of starting from nO _X is small, but not the exhaust gas recirculation necessary, the generation amount of the combustion temperature becomes high nO _X of the engine is increased, it is necessary to exhaust gas recirculation. Exhaust gas recirculation amount is desired to suppress the generation of the NO _X is increased as the combustion temperature of the engine becomes higher.

On the other hand, when exhaust gas recirculation is carried out, the generation of NO _X can be suppressed, but when the engine is operated at high speed or under high load, the output of the engine becomes insufficient and the particulate matter in the exhaust gas increases. Therefore, it is desirable to reduce the recirculation amount of exhaust gas as the engine speed or engine load increases to suppress the engine output and suppress the generation of particulate matter in the exhaust gas.

From such a viewpoint, the ECU 13 determines the cooling water temperature WT corresponding to the combustion temperature of the engine, the engine speed Ne per unit time (usually 1 minute), which is the engine speed, and the engine load. The opening / closing valve 9 is controlled based on the accelerator opening APS corresponding to That is, as the cooling water temperature WT is higher, the valve lift amount of the on-off valve 9 (because it is the valve lift amount of the EGR valve 9,
The EGR lift amount) is increased to increase the exhaust gas recirculation amount, the opening degree of the opening / closing valve 9 is decreased to decrease the exhaust gas recirculation amount as the engine speed Ne is larger, and the opening degree is increased as the accelerator opening APS is larger. The opening / closing valve 9 is controlled so that the opening degree of the valve 9 is reduced to reduce the exhaust gas recirculation amount.

The cooling water temperature WT is equal to or lower than a preset value WT ₀ (for example, WT ₀ = 70 ° C.), or the engine speed Ne is preset to a preset value Ne ₀ (for example, Ne ₀ = 3000 rpm). Or above, or accelerator opening A
PS is a preset value APS ₀ (for example, APS ₀
= 60%) or more, the on-off valve 9 is closed and the exhaust gas recirculation passage 8 is closed so that exhaust gas recirculation is not performed.

In other cases (that is, the cooling water temperature WT
Is the set value WT ₀ or more, the engine speed Ne is the set value Ne ₀ or less, and the accelerator opening APS is the set value AP.
In the case of S ₀ or less), as described above, the cooling water temperature WT,
A target value of the opening degree (target EGR lift amount) of the opening / closing valve 9 is set according to the engine speed Ne and the accelerator opening APS, and the opening degree of the opening / closing valve 9 is controlled according to the target EGR lift amount. It is like this.

For such a target EGR lift amount, for example, a three-dimensional map capable of obtaining the target EGR lift amount corresponding to the cooling water temperature WT, the engine speed Ne, and the accelerator opening APS is prepared in advance, and this map is prepared. You may make it based on. In this device, the ECU 13 corrects the obtained target EGR lift amount according to the operating state of the engine. That is, when the engine is accelerated, the target EGR lift amount is reduced, the exhaust gas recirculation amount is reduced, the engine output is easily increased quickly, and the acceleration performance in the EGR region is improved.

When the engine decelerates, the target EGR
The amount of lift is reduced, the amount of exhaust gas recirculation is reduced, the decrease in excess air ratio is suppressed, and the excess air ratio is sufficient even when deceleration is re-accelerated or deceleration shifts to steady operation. It is supposed to be secured. This is an attempt to avoid particulate matter in the exhaust gas, which increases due to a large decrease in the excess air ratio when shifting from deceleration to reacceleration or steady operation.

If the preset target EGR lift amount is small, as a result of such corrections, the target EGR lift amount is corrected to 0, that is, the target EGR lift amount is set so that exhaust gas recirculation (EGR) is not performed. In some cases. In the present embodiment, the determination of the acceleration or deceleration of the engine is made based on the accelerator opening APS. That is, for example, the accelerator opening deviation ΔAPS is obtained from the accelerator opening APS detected in each control cycle, and the accelerator opening deviation ΔAPS is obtained.
APS has a preset threshold value ΔAPS ₁ (ΔAPS ₁ >
If it is larger than 0), it is determined that the vehicle is accelerating, and the accelerator opening deviation ΔAPS is set to a preset threshold ΔAPS ₂ (Δ
If it is smaller than APS ₂ <0, it can be determined that the vehicle is decelerating.

By the way, as for the switching valve 12, basically, when the exhaust gas is being recirculated (that is, when the opening / closing valve 9 is open), the bypass passage 11 side is opened and the recirculation of the exhaust gas is stopped. When (that is, when the on-off valve 9 is closed)
To open the intercooler 10 side to the ECU 13
Is controlled. The reason why the intake air is circulated in the bypass passage 11 side instead of the intercooler 10 side is as follows. That is, the exhaust gas recirculation passage 8 is connected to the intake passage 2 upstream of the intercooler 10, and when the recirculated exhaust gas flows through the intercooler 10 together with fresh air, particulate matter matter contained in the exhaust gas is generated. Intercooler 1
It adheres to the inside of 0 and pollutes the inside of the intercooler 10 or causes clogging. Therefore, in order to avoid this inconvenience, when the exhaust gas recirculates, the intake air is supplied to the intercooler 10
The bypass passage 11 side is opened so as not to flow inside.

Even if the on-off valve 9 is closed and the exhaust gas recirculation passage 8 is closed, the particulate matter matter remains in the intake air for a while. Therefore, when the exhaust gas recirculation is stopped, the ECU 13 After a certain period of time elapses after the stoppage of the reflux, the switching valve 12 is moved from the bypass passage 11 side to the intercooler 1
It is set to switch to the 0 side. Since this fixed period generally corresponds to a fixed time after the stop of the reflux, hereinafter, the switching timing of the switching valve 12 is expressed as a fixed time after the stop of the reflux.

However, this fixed period is not necessarily limited to time, and the fixed period may be set while the engine is rotating by a predetermined number of revolutions after the stop of the recirculation. That is, after the stop of the recirculation, the switching valve 12 may be set to switch from the bypass passage 11 side to the intercooler 10 side after the engine rotates a certain number of revolutions. Since the supercharged internal combustion engine with the exhaust gas recirculation control device according to the first embodiment of the present invention is configured as described above, for example, as shown in the flowchart of FIG. 2, exhaust gas recirculation control and bypass passage switching are performed. Control is performed.

That is, as shown in FIG. 2, each information of the accelerator opening APS, the engine speed Ne, and the cooling water temperature WT is fetched from each sensor in a predetermined cycle (step A1).
0). Then, it is determined whether or not the engine operating condition is in the EGR prohibition region (step A20). That is, the cooling water temperature WT is set to a preset value WT ₀ (for example, WT
₀ = 70 ° C.) or less, or the engine speed Ne is a preset value Ne ₀ (for example, Ne ₀ = 3000 rpm)
) Or more, or when the accelerator opening APS is equal to or greater than a preset set value APS ₀ (for example, APS ₀ = 60%), the EGR prohibition region is set. In other cases, EG is set.
It becomes the R region.

If it is not in the EGR prohibited area, that is, EGR
If it is in the region, the process proceeds to step A30 to open the switching valve 12 on the bypass passage 11 side. Furthermore, step A
In step 40, the target EGR lift amount is calculated. By this calculation, the accelerator opening APS, the engine speed Ne,
Based on each information of the cooling water temperature WT, the accelerator opening APS
The target EGR lift amount decreases as the engine speed Ne increases, and the target EG lift amount decreases as the cooling water temperature WT increases.
The target EGR lift amount is given so that the R lift amount becomes large.

Next, in step A50, the accelerator opening deviation ΔAPS is calculated. This accelerator opening deviation Δ
The APS is obtained by subtracting the accelerator opening detected in the previous sampling cycle or several cycles before from the accelerator opening detected this time. Next, in step A60, it is determined whether the engine is accelerating. That is, the accelerator opening deviation ΔAPS is compared with the acceleration threshold value ΔAPS ₁ (ΔAPS ₁ is a preset positive value), and if the accelerator opening deviation ΔAPS is equal to or greater than the acceleration threshold value ΔAPS ₁ (that is, ΔAPS ≧ ΔAPS ₁ ). ,
It is determined that the engine is accelerating. If you're accelerating,
The process proceeds to step A70 to correct the target EGR lift amount. That is, the target EGR lift amount is reduced and the exhaust gas recirculation amount is reduced. This decrease in the exhaust gas recirculation amount makes it easier to increase the engine output quickly, and
The acceleration performance in the R region can be improved.

If the engine is not accelerating, step A
The routine proceeds from 60 to step A80, where it is determined whether the engine is decelerating. That is, the accelerator opening deviation ΔAPS is compared with the acceleration threshold ΔAPS ₂ (ΔAPS ₂ is a preset negative value), and the accelerator opening deviation ΔAPS ₂ is compared.
Is less than or equal to the acceleration threshold ΔAPS ₂ (that is, ΔAPS ≦ ΔA
PS ₂ ) and it is determined that the engine is decelerating. If the vehicle is decelerating, the routine proceeds to step A90, where the target EGR lift amount is corrected. That is, by reducing the target EGR lift amount,
Reduce exhaust gas recirculation. In this way, by reducing the exhaust gas recirculation amount during deceleration, a decrease in the excess air ratio is suppressed, and the excess air ratio remains unchanged even when the vehicle accelerates again from deceleration or shifts from deceleration to steady operation. It is sufficiently secured and the increase of particulate matter in the exhaust gas is suppressed.

If the target EGR lift amount calculated in step A40 is small, such steps A70, A9
As a result of each correction of 0, the target EGR lift amount may be corrected to 0, that is, the target EGR lift amount that does not perform exhaust gas recirculation (EGR). When accelerating or decelerating, corrections during acceleration and deceleration like these are performed,
When the vehicle is traveling at a constant speed, the acceleration correction and the deceleration correction are not performed, and the process directly proceeds from step A80 to step A100, and based on the target EGR lift amount that is appropriately corrected, the opening / closing valve (EGR valve). A drive command is issued to 9.

Then, the process proceeds to step A110, where the flag F is set to 1 and the process stands by until the next control cycle. This flag F is 1 when exhaust gas recirculation (EGR) is being performed.
Is set to 0 when exhaust gas recirculation (EGR) is not performed, and is initialized to 0 at the start of control. In this way, when the operating state of the engine is in the EGR region, the opening / closing valve 9 is opened by an opening degree corresponding to the target EGR lift amount to perform exhaust gas recirculation, thereby lowering the combustion temperature of the engine. NOx in exhaust gas is reduced.

Further, in general, such reduction of NOx causes an increase in particulate matter in the exhaust gas, which is contrary to this, and such an increase in particulate matter causes a narrow intake passage. Intercooler 1
It easily leads to 0 contamination and induces clogging. However, in this device, when such exhaust gas recirculation is performed, Step A
At 30, the switching valve 12 is opened to the side of the bypass passage 11 and the intake air bypasses the intercooler 10, so that the contamination and clogging of the intercooler 10 are prevented.

The recirculation of the exhaust gas is performed in the exhaust passage 3 from the downstream side of the turbine 5 in the intake passage 2
Connection passage 8 leading upstream of the compressor 6 in
The exhaust gas after driving the turbine 5 is recirculated to the intake passage 2. For this reason, exhaust gas recirculation can be performed while the turbine is reliably driven by fully utilizing the energy of the exhaust gas, and the supercharging pressure is secured even during exhaust gas recirculation.

Further, since the temperature of the exhaust gas after driving the turbine 5 is lowered, the lower temperature exhaust gas is recirculated to the intake passage 2. Therefore, the rise of the intake air temperature flowing into the compressor 6 is also suppressed, and the heating of the compressor 6 can be suppressed. It becomes easy to avoid heat damage to the compressor 6. Further, by ensuring the recirculation of the low-temperature exhaust gas and the supercharging pressure, the equivalence ratio of the fresh air and the recirculation exhaust gas in the intake passage 2 is increased, and a sufficient air amount is easily supplied to the engine. Therefore, the combustion of the engine becomes easier to be performed in the complete combustion state.

As a result, the output of the engine is secured and the generation of particulate matter due to combustion is suppressed. On the other hand, the accelerator opening APS, the engine speed Ne, and the cooling water temperature W taken in step A10.
Based on each information of T, the cooling water temperature WT is less than or equal to a preset value WT ₀ (for example, WT ₀ = 70 ° C.), or
The engine speed Ne is equal to or higher than a preset value Ne ₀ (for example, Ne ₀ = 3000 rpm) or the preset value APS ₀ (for example, APS) where the accelerator opening APS is preset.
₀ = 60%) or more, it is determined in step A20 that the operating state of the engine is in the EGR prohibition region.

In this case, the process proceeds to step A120 to issue the EGR prohibition command. That is, the on-off valve (EGR
The valve 9 is instructed to close. Further, step A1
In step 30, it is determined whether the flag F is 1.
When the exhaust gas recirculation (EGR) is being performed in the previous control cycle, the flag F is set to 1. Therefore, the process proceeds from step A130 to step A140, and the timer value T is started to be counted by a timer (not shown). To do. This timer is activated only when a count start command is issued in step A140.

Then, the process proceeds to step A150, sets the flag F to 0, and proceeds to step A160. Step A1
At 60, it is determined whether or not the timer value T has reached a preset value T ₁ . Since the timer has just started in the control cycle just after switching from the EGR region to the EGR prohibition region, the timer value T has not reached the set value T ₁ , so the state of the switching valve 11 is not changed, that is, the bypass passage is not changed. The control cycle of this time is ended with the 11th side open.

When the state of the EGR prohibition region continues, from the next control cycle, through steps A10, A20, A120, and step A130, the step A17 is judged.
The routine proceeds to 0, where the timer value T is incremented by a value t corresponding to the control cycle, and the routine proceeds to step A160, where it is determined whether or not the timer value T has reached the set value T ₁ . If the timer value T does not reach the set value T ₁ , the control cycle of this time is ended while the switching valve 11 remains open on the bypass passage 11 side. When only the duration corresponding to the set value T _1, it is determined that the timer value T reaches the set value T ₁ in step a 160, the process proceeds to step A180.

In step A180, the state of the switching valve 11 is set to the open state on the intercooler 10 side, and the supply air is circulated to the intercooler 10 side. In this way, EGR
Even if the region is switched to the EGR prohibited region, the state of the switching valve 11 is not immediately switched to the intercooler 10 side, but the intercooler 10 side is opened after a certain period of time, so that the intercooler 10 by the particulate matter is opened.
Internal contamination and clogging are avoided. That is, even if the exhaust gas recirculation passage 8 is closed, the inside of the intake passage and the exhaust gas recirculation passage 8 are closed.
Particulate matter in the exhaust gas that has already recirculated remains in the portion on the downstream side of the on-off valve 9, and it takes a certain time until the remaining particulate matter is wiped out. In this device, the intercooler 10 side is opened after a lapse of time until the remaining particulate matter is completely cleaned. Therefore,
When the intercooler 10 side is opened, the particulate matter on the intake passage side has already been discharged, and the contamination and clogging of the intercooler 10 by the particulate matter are prevented.

The acceleration / deceleration of the engine may be determined based on the engine speed Ne. That is, for example, the engine speed deviation ΔNe is obtained from the engine speed Ne detected in each control cycle, and if the engine speed deviation ΔNe is larger than a preset threshold value ΔNe ₁ (ΔNe ₁ > 0), acceleration is being performed. Engine speed deviation ΔNe
Is smaller than a preset threshold ΔNe ₂ (ΔNe ₂ <0), it can be determined that the vehicle is decelerating.

In addition to the accelerator opening APS and the engine speed Ne itself, the vehicle speed value V and the supercharging pressure P _EGR can be used. That is, for example, the vehicle speed deviation ΔV is obtained from the vehicle speed value V detected in each control cycle, and if the vehicle speed deviation ΔV is larger than a preset threshold value ΔV ₁ (ΔV ₁ > 0), it is determined that acceleration is in progress. If the engine speed deviation ΔV is smaller than a preset threshold value ΔV ₂ (ΔV ₂ <0), it can be determined that the vehicle is decelerating.

Further, for example, the supercharging pressure deviation ΔP _TC is obtained from the supercharging pressure P _TC detected in each control cycle, and the supercharging pressure deviation ΔP _TC is a preset threshold ΔP _TC1 (ΔP _TC1 >
If it is greater than 0), it is determined that acceleration is in progress, and the engine speed deviation ΔP _TC is a preset threshold ΔP _TC2 (ΔP _TC
If it is smaller than _TC2 <0), it can be judged that the vehicle is decelerating.

Next, a supercharged internal combustion engine with an exhaust gas recirculation control system according to the second embodiment will be described. FIG. 3 is a schematic diagram showing an intake / exhaust route of this engine, and FIG. 1 (first embodiment). The same reference numerals as in FIG. In this embodiment, an intake air temperature sensor 14 is provided in the intake passage 2 as an engine operation information detecting means. This intake air temperature sensor 1
4 is provided immediately upstream of the compressor 6 downstream of the opening of the exhaust gas recirculation passage (connection passage) 8 so that the intake air temperature flowing into the compressor 6 can be detected. Further, the intake air temperature sensor 14 is
The intake air temperature flowing into the compressor 6 is taken into the ECU 13 as one of the engine operation information.

In the ECU 13, a condition that the exhaust gas recirculation is not performed (EGR prohibition region) is that the intake air temperature Tt flowing into the compressor 6 is equal to or higher than a preset Tt ₀ . That is, in the present embodiment, the EGR prohibited area is equal to or lower than the preset value WT ₀ (for example, WT ₀ = 70 ° C.) of the cooling water temperature WT, or
The engine speed Ne is equal to or higher than a preset value Ne ₀ (for example, Ne ₀ = 3000 rpm) or the preset value APS ₀ (for example, APS) where the accelerator opening APS is preset.
₀ = 60%) or higher, or the intake air temperature Tt flowing into the compressor 6 is equal to or higher than a preset temperature Tt ₀ .

The intake temperature Tt is targeted as the EGR prohibition region in this manner in order to reliably avoid damage to the compressor 6 due to heat. That is, since the exhaust gas is generally high in temperature, when the exhaust gas is recirculated into the intake air, the intake air temperature also rises significantly. In the general turbocharger 4, a material having sufficient heat resistance is used for the turbine 5, but such a material having heat resistance is not used for the compressor 6. Therefore, when the exhaust gas is recirculated, the intake air temperature rises significantly, which may cause heat damage to the compressor 6. Of course,
This can be avoided also by using a highly heat-resistant material for the compressor 6, but in this case, a large cost increase is incurred.

Therefore, in this apparatus, while monitoring the intake air temperature Tt so that the compressor 6 is not exposed to a high temperature, when the intake air temperature Tt becomes equal to or higher than the set temperature Tt ₀ , the recirculation of the exhaust gas is stopped and the intake air temperature Tt is adjusted. I am trying to lower it. At the set temperature Tt _0, the intake is the compressor 6
It is given as an upper limit temperature value which does not give heat loss to or a set temperature value obtained by multiplying the upper limit temperature value by a safety factor.

In this embodiment, the other structures are the same as those in the first embodiment, and the other control by the ECU 13 is also the first.
The procedure is similar to that of the embodiment. That is,
If it is not in the EGR prohibition region, EGR is performed, but in this case, similar to the first embodiment, the target EGR lift amount is calculated based on each information of the accelerator opening APS, the engine speed Ne, and the cooling water temperature WT. When the engine is accelerated or decelerated, the target EGR lift amount is further corrected, and then the opening / closing valve (EGR valve) 9 is set based on the target EGR lift amount.
It is designed to issue a drive command to.

Since the supercharged internal combustion engine with the exhaust gas recirculation control device according to the second embodiment of the present invention is constructed as described above, the exhaust gas recirculation control and the bypass passage switching control are shown in FIG. Thus, except for the EGR prohibition determination,
The same operation as in the embodiment is performed. Therefore, the difference from the first embodiment will be described. First, at step A12, the intake air temperature Tt flowing into the compressor 6 in addition to the accelerator opening APS, the engine speed Ne, the cooling water temperature WT.
Take in. The intake air temperature Tt flowing into the compressor 6 is determined by the EGR prohibition determination in step A22.
Taking into consideration the above, the EGR prohibition determination is performed.

That is, the cooling water temperature WT is equal to or lower than the preset value WT ₀ (for example, WT ₀ = 70 ° C.), or the engine speed Ne is preset to the preset value Ne ₀ (for example, Ne ₀ = 3000 rpm). Or above, or accelerator opening A
PS is a preset value APS ₀ (for example, APS ₀
= 60%) or more, and also when the intake air temperature Tt flowing into the compressor 6 is equal to or more than a preset Tt ₀ ,
It is determined that EGR is prohibited. The other control procedure is performed in the same manner as in the first embodiment, and the description is omitted.

As described above, in this embodiment, even when the intake air temperature Tt flowing into the compressor 6 becomes equal to or higher than the set temperature Tt ₀ , the exhaust gas recirculation is prohibited and the high temperature exhaust gas flows into the intake air. Since it disappears, the compressor 6 will not be exposed to high temperatures. As a result, even if the compressor 6 is made of a material that does not have particularly high heat resistance, the compressor 6 will not be damaged by heat.

Also, in this embodiment, various effects similar to those of the first embodiment can be obtained. That is, the supercharging pressure due to the exhaust gas being recirculated from the downstream side of the turbine 5 to the upstream side of the compressor 6 can be secured, and the low temperature exhaust gas can be recirculated, so that the output of the engine can be secured and the particulate matter can be reduced. . Also, the effect of improving the acceleration performance in the EGR region by controlling the exhaust gas recirculation amount during acceleration, and the re-acceleration from deceleration and the transition to steady-state operation by controlling the exhaust gas recirculation amount during deceleration are performed. The effect of suppressing the increase in matter is obtained. Further, by circulating the intake air so as to bypass the intercooler 10 during the exhaust gas recirculation and within a predetermined time after the exhaust gas recirculation is stopped, contamination and clogging of the intercooler 10 due to the exhaust gas recirculation are prevented. The effect is also obtained.

Next, a supercharged internal combustion engine with an exhaust gas recirculation control system according to the third embodiment will be described. FIG. 5 is a schematic diagram showing an intake / exhaust route of this engine.
The same symbols as those in the second embodiment indicate the same. In this embodiment, the exhaust gas recirculation passage (connection passage) in the intake passage 2
An intake throttle valve 15A is provided in the upstream portion of the opening of No. 8, and by restricting this intake throttle valve 15A, the introduction of fresh air from the intake passage 2 is suppressed, and the pressure in the upstream and downstream of the exhaust gas recirculation passage 8 is reduced. It is configured to increase the difference. this is,
Generally, the differential pressure between the pressure (back pressure) on the downstream side of the exhaust turbine 5 and the pressure (atmospheric pressure) on the upstream side of the intake air compressor 6 is small, and the exhaust gas recirculation amount (EGR gas amount) is reduced in the exhaust gas recirculation passage 8. It is not possible to make it large, so we are trying to solve this. That is, the intake throttle valve 15A is throttled to suppress the introduction of fresh air from the intake passage 2, thereby lowering the pressure on the downstream side of the exhaust gas recirculation passage 8 and increasing the pressure difference on the upstream and downstream sides of the exhaust gas recirculation passage 8. Therefore, the exhaust gas recirculation amount is to be increased.

The intake throttle valve 15A can adjust the opening degree (that is, the degree of throttle), and this opening degree adjustment is performed together with the opening degree adjustment of the opening / closing valve 9. Here, when a large exhaust gas recirculation amount is not required, the intake throttle valve 15A is not throttled, and the exhaust gas recirculation amount is adjusted by adjusting the opening degree of only the on-off valve 9, and a large exhaust gas return amount equal to or greater than a predetermined value is adjusted. When the flow rate is required, the opening / closing valve 9 is adjusted while the intake throttle valve 15A is throttled to adjust the exhaust gas recirculation amount.

That is, if the required exhaust gas recirculation amount is less than the predetermined value, the ECU 13 fully opens the intake throttle valve 15A and makes a request based on the accelerator opening APS, the engine speed Ne, and the cooling water temperature WT. The target EGR lift amount is calculated so that the exhaust gas recirculation amount is realized, and the opening degree of the opening / closing valve 9 is adjusted according to the target EGR lift amount.

If the required exhaust gas recirculation amount is equal to or greater than a predetermined value, the ECU 13 realizes the required exhaust gas recirculation amount based on the accelerator opening APS, the engine speed Ne, and the cooling water temperature WT. Then, the target throttle amount of the intake throttle valve 15A and the target EGR lift amount of the on-off valve 9 are set, and the opening amounts of the intake throttle valve 15A and the on-off valve 9 are adjusted according to the target throttle amount and the target EGR lift amount.

Further, the ECU 13 corrects the target throttle amount and the target EGR lift amount when the engine is accelerated or decelerated, as in the first embodiment, and the corrected target EGR lift amount is corrected. A drive command is issued to the opening / closing valve (EGR valve) 9 based on the lift amount. In this embodiment, the other configurations are the same as those in the first embodiment, and the other control by the ECU 13 is also performed in the same manner as in the first embodiment.

Since the supercharged internal combustion engine with the exhaust gas recirculation control device of the third embodiment of the present invention is constructed as described above, the exhaust gas recirculation control and the bypass passage switching control are shown in FIG. Is done as follows. That is, as shown in FIG. 6, as in the first embodiment, each information of the accelerator opening APS, the engine speed Ne, and the cooling water temperature WT is fetched from each sensor in a predetermined cycle (step A10). And
Whether the engine operating state is in the EGR prohibition region or not is determined by the cooling water temperature WT, the engine speed Ne, the accelerator opening APS.
(Step A20).

If it is not in the EGR prohibition region, that is, if it is in the EGR region, the process proceeds to step A30 to open the switching valve 12 on the bypass passage 11 side. Furthermore, the routine proceeds to step A42, where the target EGR lift amount and the target throttle amount of the intake throttle valve 15A are calculated. This calculation is performed based on each information of the accelerator opening APS, the engine speed Ne, and the cooling water temperature WT.
The target EGR lift amount decreases as S and the engine speed Ne increase, and the target E increases as the cooling water temperature WT increases.
The target EGR lift amount is given so that the GR lift amount becomes large. Further, when the required exhaust gas recirculation amount is less than the predetermined value and the target EGR lift amount is smaller than the predetermined value, the intake throttle valve 15A is fully opened and throttle control is not performed, and the required exhaust gas recirculation amount is the predetermined amount. Target EG above the value
When the R lift amount is equal to or larger than a predetermined value, the intake throttle valve 15A
The target aperture amount is set and the aperture control is performed in step A102 described later.

Next, as in the first embodiment, step A5
The accelerator opening deviation ΔAPS is calculated at 0, and step A
In step 60, the accelerator opening deviation ΔAPS is set to the acceleration threshold ΔA.
PS ₁Determine if the engine is accelerating by comparing with
I do. If the engine is accelerating, proceed to step A72
Therefore, the target EGR lift amount is corrected, and if necessary,
The target throttle amount of the intake throttle valve 15A is corrected. That is, the goal
The EGR lift amount is reduced and the target throttle of the intake throttle valve 15A is reduced.
Decrease the amount of exhaust gas (increase the opening) to reduce the amount of exhaust gas recirculation
Let Due to this reduction in the exhaust gas recirculation amount, the engine output
Accelerates in the EGR region by making it easier to increase force quickly
The performance can be improved.

If the engine is not accelerating, step A
The routine proceeds from step 60 to step A80, where the accelerator opening deviation Δ
APS is compared to the acceleration threshold APS ₂ to determine if the engine is decelerating. If the engine is slowing down,
The routine proceeds to step A92, where the target EGR lift amount (target EG
R) and, if necessary, the target throttle amount of the intake throttle valve 15A. That is, the target EGR lift amount is decreased, the target throttle amount of the intake throttle valve 15A is decreased (the opening degree is increased), and the exhaust gas recirculation amount is decreased. In this way, by reducing the exhaust gas recirculation amount during deceleration, a decrease in the excess air ratio is suppressed, and the excess air ratio remains unchanged even when the vehicle accelerates again from deceleration or shifts from deceleration to steady operation. It is sufficiently secured and the increase of particulate matter in the exhaust gas is suppressed.

If the target EGR lift amount calculated in step A42 is small, such steps A72, A9
As a result of each correction of No. 2, the target EGR lift amount may be corrected to 0, that is, the target EGR lift amount that does not perform exhaust gas recirculation (EGR). Further, if the target throttle amount of the intake throttle valve 15A calculated in step A42 is small, as a result of the corrections in steps A72 and A92, the target throttle amount is set to 0, that is, the intake throttle is fully opened. It may be corrected so as not to perform control.

When accelerating or decelerating, corrections during acceleration and deceleration are performed as described above, but during constant speed running,
Without performing the acceleration correction and the deceleration correction as described above, the process directly proceeds from step A80 to step A102, and based on the appropriately corrected target EGR lift amount and target throttle amount, the opening / closing valve (EGR valve) 9 A drive command is issued to the intake throttle valve 15A.

Then, the process proceeds to step A110, where the flag F is set to 1 and the process stands by until the next control cycle. In this way, when the operating state of the engine is in the EGR region, the opening / closing valve 9 is opened by an opening degree corresponding to the target EGR lift amount to perform exhaust gas recirculation, thereby lowering the combustion temperature of the engine. NOx in exhaust gas is reduced.

In particular, the differential pressure between the pressure (back pressure) on the downstream side of the exhaust turbine 5 and the pressure (atmospheric pressure) on the upstream side of the air supply compressor 6 is generally small, and the exhaust gas recirculation amount (EGR The exhaust gas recirculation amount is limited because the gas amount) cannot be increased, but here, the pressure on the downstream side of the exhaust gas recirculation passage 8 is suppressed by restricting the intake throttle valve 15A to suppress the introduction of fresh air from the intake passage 2. Since the pressure difference between the upstream side and the downstream side of the exhaust gas recirculation passage 8 can be increased, the exhaust gas recirculation amount can be sufficiently increased.

Of course, in response to such an increase in particulate matter which becomes a problem when exhaust gas recirculates, in step A30, the switching valve 12 is opened to the bypass passage 11 side so that intake air bypasses the intercooler 10. Therefore, as in the first embodiment, the contamination and clogging of the intercooler 10 are prevented. In addition, the turbine 5 of the exhaust passage 3
By performing exhaust gas recirculation through the connection passage 8 that leads from the downstream side to the upstream side of the compressor 6 in the intake passage 2, the supercharging pressure is ensured during exhaust gas recirculation as in the first embodiment. Alternatively, the exhaust gas of lower temperature is recirculated to the intake passage 2 to facilitate combustion of the engine in a more complete combustion state, the output of the engine is secured, and the generation of particulate matter is suppressed.

On the other hand, if it is determined in step A20 that the operating state of the engine is in the EGR prohibition region, the control of steps A120 to A180 is performed thereafter, as in the first embodiment. The same action and effect as those of the first embodiment can be obtained. Especially from the EGR region to the EGR
Since the intercooler 10 side is opened after a lapse of a certain time after switching to the prohibited area, there is an effect that contamination and clogging in the intercooler 10 due to particulate matter can be avoided.

As shown in FIG. 7, an exhaust throttle valve 15B may be provided instead of the intake throttle valve 15A in the third embodiment to control the exhaust throttle valve 15B.
That is, in the structure shown in FIG. 7, the exhaust throttle valve 15B is provided in the exhaust passage 3 downstream of the opening of the exhaust gas recirculation passage (connection passage) 8.
Is configured to increase the pressure in the vicinity of the opening of the exhaust gas recirculation passage 8 of the exhaust passage 3 to increase the pressure difference between the upstream and downstream of the exhaust gas recirculation passage 8. This exhaust throttle valve 15B is an alternative to the intake throttle valve 15A of the third embodiment. The exhaust throttle valve 15B is throttled to increase the pressure in the exhaust passage 3 and increase the pressure difference between the upstream and downstream of the exhaust gas recirculation passage 8. By doing so, the exhaust gas recirculation amount is increased.

The exhaust throttle valve 15B can also adjust the opening degree (that is, the degree of throttle), and this opening degree adjustment is performed together with the opening degree adjustment of the on-off valve 9. In particular, when a large exhaust gas recirculation amount is not required, the exhaust throttle valve 1
5B is not throttled, the exhaust gas recirculation amount is adjusted by adjusting the opening degree of only the on-off valve 9, and when a large exhaust gas recirculation amount of a predetermined value or more is required, the on-off valve is throttled while the exhaust throttle valve 15B is throttled. The opening degree of 9 is adjusted to adjust the exhaust gas recirculation amount.

That is, if the required exhaust gas recirculation amount is less than the predetermined value, the ECU 13 fully opens the exhaust throttle valve 15B and makes a request based on the accelerator opening APS, the engine speed Ne, and the cooling water temperature WT. The target EGR lift amount is calculated so as to realize the exhaust gas recirculation amount, the target opening degree of the opening / closing valve 9 (target EGR lift amount) is set, and the opening degree of the opening / closing valve 9 is adjusted according to the target EGR lift amount. It is supposed to do.

If the required exhaust gas recirculation amount is greater than or equal to a predetermined value, the ECU 13 realizes the required exhaust gas recirculation amount based on the accelerator opening APS, engine speed Ne, and cooling water temperature WT. Then, the target throttle amount of the exhaust throttle valve 15B and the target EGR lift amount of the on-off valve 9 are set, and the opening degrees of the exhaust throttle valve 15B and the on-off valve 9 are adjusted according to the target throttle amount and the target EGR lift amount.

Further, the ECU 13 determines the target throttle amount and the target EGR lift amount when the engine is accelerated or decelerated, as in the first to third embodiments.
After further correcting the lift amount, a drive command is issued to the opening / closing valve (EGR valve) 9 based on the target EGR lift amount. In the present embodiment, other configurations are the same as those in the third embodiment, and other control by the ECU 13 is also performed in the same manner as in the third embodiment.

Since the supercharged internal combustion engine with an exhaust gas recirculation control device as a modification of the third embodiment is configured as described above, the exhaust gas recirculation control and the bypass passage switching control are performed as follows. The procedure is similar to that of the third embodiment.
That is, in step A42 of FIG. 6 in the third embodiment,
If necessary, the target throttle amount of the exhaust throttle valve 15B is set, and the throttle control by the exhaust throttle valve 15B is performed in step A102. The other respective controls are performed in the same manner as in the third embodiment.

In this way, the same operation and effect as those of the first and third embodiments can be obtained while utilizing the exhaust throttle control. In particular, as in the first embodiment, generally, the pressure difference between the downstream pressure (back pressure) of the exhaust turbine 5 and the upstream pressure (atmospheric pressure) of the air supply compressor 6 is small, and the exhaust gas recirculation passage 8 exhausts the exhaust gas. The exhaust gas recirculation amount is limited because the gas recirculation amount (EGR gas amount) cannot be increased. However, by restricting the exhaust throttle valve 15B to suppress the introduction of fresh air from the intake passage 2, the downstream side of the exhaust gas recirculation passage 8 is suppressed. Since the pressure difference between the upstream side and the downstream side of the exhaust gas recirculation passage 8 can be increased, the exhaust gas recirculation amount can be sufficiently increased.

As shown in FIG. 8, a filter 16 is provided in the middle of the exhaust gas recirculation passage 8 to trap particulate matter in the recirculated exhaust gas so that clean exhaust gas is introduced into the intake passage. It may be configured so as to return to 2 and return. In this case, the risk of contamination or clogging of the intercooler 10 due to exhaust gas recirculation is reduced, but by using the bypass passage 11 that bypasses the intercooler 10, the contamination and clogging of the intercooler 10 can be prevented more reliably.

Further, as shown in FIG. 9, a cooler (heat exchanger) 17 may be provided in the exhaust gas recirculation passage 8 to cool the recirculated exhaust gas in advance. In this case, since the intake air temperature flowing into the compressor 6 is lowered, the compressor 6 is not exposed to a high temperature,
Even if the compressor 6 is formed of a material that does not have particularly high heat resistance, there is an advantage that the compressor 6 is not damaged by heat.

Next, a supercharged internal combustion engine with an exhaust gas recirculation control device according to a fourth embodiment will be described. FIG. 10 is a schematic diagram showing an intake / exhaust route of this engine.
The same reference numerals as 7, 8, 9 denote the same. As shown in FIG. 10, in this embodiment, the exhaust gas recirculation passage is composed of two connection passages 8 and 18 and opening / closing valves (EGR valves) 9 and 19 interposed in the connection passages 8 and 18, respectively. There is. The connection passage (first connection passage) 8 communicates between the exhaust passage 3 downstream of the turbine 5 and the intake passage 2 upstream of the compressor 6, as in the first to third embodiments. The other connection passage (second connection passage) 18 communicates between the exhaust passage 3 upstream of the turbine 5 and the intake passage 2 downstream of the compressor 6. It is arranged so that

In the first connection passage 8, the exhaust gas whose temperature has decreased after driving the turbine 5 is recirculated to the intake passage 2, so that the supercharging pressure by the turbocharger 4 is secured and the temperature of the lower temperature becomes lower. By recirculating the exhaust gas, the equivalence ratio between the fresh air and the recirculating exhaust gas in the intake passage 2 is increased, so that a sufficient amount of air is easily supplied to the engine 1, and NOx reduction and particulate matter reduction are both achieved. The engine output can be secured. On the other hand, in the second connection passage 18, the recirculation amount of the exhaust gas is easily increased as compared with the first connection passage 8, and the NOx reduction effect is remarkable.

Since two exhaust gas recirculation passages and two on-off valves (EGR valves) are provided in this manner, the exhaust gas recirculation control in the device of this embodiment is different from that in the device of the first embodiment. There is. That is, in the present device, a region for prohibiting exhaust gas recirculation by the first connection passage 8 is provided,
When the exhaust gas recirculation through the first connecting passage 8 is prohibited, the opening / closing valve (first EGR valve) 9 is closed and the opening / closing valve (second EGR valve) 19 is opened, so that the second connecting passage 1
Exhaust gas recirculation is performed by 8. As a matter of course, the operating state of the engine is determined based on the detected values to be EGR by the first connecting passage 8.
If it is not in the prohibited area, the on-off valve (second EGR valve) 19
Is closed and the on-off valve (first EGR valve) 9 is opened, and exhaust gas recirculation is performed by the first connection passage 8. The first
The exhaust gas recirculation by the connection passage 8 is called a first EGR, and the exhaust gas recirculation by the second connection passage 19 is called a second EGR.

The prohibition of the first EGR (exhaust gas recirculation by the first connecting passage 8) corresponds to prohibition of the exhaust gas recirculation itself in the first embodiment, and the accelerator opening APS, the engine speed Ne, and the cooling water temperature WT are set. Based on the first connection passage 8
The EGR prohibited area is set. That is, in the present device, the ECU 13 opens the first connection passage 8 to open the second connection passage 18 under a situation in which the engine output request and the factor of increasing the particulate matter in the exhaust gas are large.
Is controlled so that the second connection passage 18 is opened and the first connection passage 8 is opened under a situation where there are few factors for increasing the output demand of the engine or the particulate matter in the exhaust gas.
Control to close.

The configuration of each of the other parts of the apparatus is the first
The description is omitted because it is similar to the embodiment. Fourth of the present invention
The supercharged internal combustion engine with the exhaust gas recirculation control device of the embodiment,
With the above-described configuration, the exhaust gas recirculation control and the bypass passage switching control are performed as shown in FIG. 11, for example.

That is, as shown in FIG. 11, each information of the accelerator opening APS, the engine speed Ne, and the cooling water temperature WT is fetched from each sensor at a predetermined cycle (step B1).
0). Then, it is determined whether the operating state of the engine is in a region where the EGR by the first connection passage 8 is prohibited (that is, the first EGR prohibited region) (step B12). Specifically, the cooling water temperature WT is a preset value WT
₀ (for example, WT ₀ = 70 ° C.) or less, or a set value Ne ₀ (for example, Ne ₀ ) in which the engine speed Ne is set in advance.
= 3000 rpm) or more, or a preset value APS ₀ (for example, APS ₀ = 60) in which the accelerator opening APS is preset.
%) Or more, it is the first EGR prohibited area and the second
This is the second EGR region in which the EGR is performed by the connection passage 19, and in other cases, the EGR is performed by the first connection passage 8.
It becomes the 1st EGR area which does.

If it is not the first EGR prohibition region, that is, if it is the first EGR region (the region where the EGR can be performed by the first connecting passage 8), the routine proceeds to step B20, where acceleration judgment is performed. Although details of the acceleration determination step will be described later, if it is determined that the vehicle is accelerating, the process proceeds from step B60 to step B70 to set the target E of the first EGR valve 9.
Calculate the GR lift amount. That is, the accelerator opening APS,
The target EGR lift amount for the first EGR valve 9 is calculated based on each information such as the engine speed Ne and the cooling water temperature WT. In this calculation, as described above, the target EGR lift amount decreases as the accelerator opening APS and the engine speed Ne increase, and the target EGR lift amount increases as the cooling water temperature WT increases.

The target EGR lift amount is calculated by, for example, the cooling water temperature WT, the engine speed Ne, and the accelerator opening A.
It may be obtained from a three-dimensional map regarding PS. Further, the calculation result may be subjected to acceleration correction. This acceleration correction reduces the target EGR lift amount and reduces the exhaust gas recirculation amount. This decrease in the exhaust gas recirculation amount makes it easier to increase the engine output quickly, and
The acceleration performance in the R region can be improved.

After calculating the target EGR lift amount in this way, the routine proceeds to step B80, where the first EGR valve 9 is driven so that the lift amount becomes the target EGR lift amount, and the first EGR valve 9 is driven.
EGR, that is, exhaust gas recirculation by the first connection passage 8 is performed. At this time, the second EGR valve 19 is closed. Then, the process proceeds to step B90, the switching valve 12 is opened to the bypass passage 11 side, and further, step B
The routine proceeds to 100, sets the flag F to 1, and stands by until the next control cycle.

On the other hand, if the vehicle is not in the first EGR prohibited area but is not accelerating, the process proceeds from step B60 to step B110, and if it is in the first EGR prohibited area, step B is performed.
It progresses from 12 to step B110. In step B110, the target EGR lift amount of the second EGR valve 19 is calculated. That is, accelerator opening APS, engine speed N
The target EGR lift amount for the second EGR valve 19 is calculated based on each information such as e and the cooling water temperature WT. In this calculation, as described above, the target EGR lift amount decreases as the accelerator opening APS and the engine speed Ne increase, and the target EGR lift amount increases as the cooling water temperature WT increases.

The calculation of this target EGR lift amount is also
For example, it may be obtained from a three-dimensional map regarding the cooling water temperature WT, the engine speed Ne, and the accelerator opening APS. Further, the calculation result may be decelerated and corrected. In this deceleration correction, the target EGR lift amount is reduced and the exhaust gas recirculation amount is reduced. In this way, by reducing the exhaust gas recirculation amount during deceleration, a decrease in the excess air ratio is suppressed, and the excess air ratio remains unchanged even when the vehicle accelerates again from deceleration or shifts from deceleration to steady operation. It is sufficiently secured and the increase of particulate matter in the exhaust gas is suppressed.

When the target EGR lift amount is calculated in this way, the routine proceeds to step B120, where the second EGR valve 19 is driven so that the lift amount becomes the target EGR lift amount,
The second EGR, that is, the exhaust gas recirculation by the second connection passage 18 is performed. In this way, the high-temperature exhaust gas recirculates to the intake passage 2 without flowing through the intercooler 10 and the compressor 6 on the upstream side of the intercooler 10 through the second connection passage 18, so that the exhaust gas recirculates to recirculate in the exhaust gas. while the NO _X suppressing generation, compressor 6 to be subject to thermal effects it is prevented by the exhaust gas.

Further, the process proceeds to step B130, and it is determined whether or not the flag F is 1. In the last control cycle,
When the exhaust gas recirculation (EGR) is being performed, the flag F is set to 1. Therefore, the process proceeds from step B130 to step B140, and the timer (not shown) starts counting the timer value T. This timer is activated only when a count start command is issued in step B140.

Then, the process proceeds to step B150, sets the flag F to 0, and proceeds to step B160. Step B1
At 60, it is determined whether or not the timer value T has reached a preset value T ₁ . Since the timer has just started in the control cycle just after switching from the EGR region to the EGR prohibition region, the timer value T has not reached the set value T ₁ , so the state of the switching valve 11 is not changed, that is, the bypass passage is not changed. The control cycle of this time is ended with the 11th side open.

If the first EGR prohibition region or the non-acceleration state continues, from the next control cycle, step B1
0, B12 to steps B110, B120, or steps B10, B12, B20, B60 to step B11.
After 0, B120, and the judgment of step B130,
In step B170, the timer value T is incremented by a value t corresponding to the control cycle, and in step B160, it is determined whether or not the timer value T has reached the set value T ₁ .

If the timer value T does not reach the set value T ₁ , the current control cycle is ended while the switching valve 11 remains open on the side of the bypass passage 11, but the EGR prohibition region or the accelerating state is the set value. continuing for a time corresponding to T _1, the timer value T is determined to have reached the set value T ₁ in step B 160, the process proceeds to step B180. This step B
At 180, the state of the switching valve 11 is set to the open state on the intercooler 10 side, and the supply air is circulated to the intercooler 10.

In the EGR through the second connecting passage 18, the recirculated exhaust gas flows into the downstream side of the intercooler 10 and does not flow into the intercooler 10. Therefore, the recirculated exhaust gas does not pollute the inside of the intercooler 10. From EGR by the first connecting passage 8 to EG by the second connecting passage 18
Immediately after switching to R, even if the first connection passage 8 is closed, the particulate matter in the exhaust gas that has already recirculated remains in the intake passage and the portion of the first connection passage 8 downstream of the on-off valve 9. However, it takes a certain amount of time for the remaining particulate matter to be wiped out.

Here, since the intercooler 10 side is opened after a certain period of time so as to wait for the remaining particulate matter to be swept away, the inside of the intercooler 10 is contaminated by the particulate matter and the eyes are contaminated. The clogging is avoided. By the way, there are various engine acceleration determination routines as shown in FIGS.

For example, in the acceleration determination routine shown in FIG. 12, first, at step B22, the accelerator opening deviation ΔAPS.
To calculate. The accelerator opening deviation ΔAPS is obtained by subtracting the accelerator opening detected in the previous sampling cycle or some previous sampling cycles from the accelerator opening detected this time. Next, the routine proceeds to step B24, where it is determined whether or not the engine is accelerating based on the accelerator opening deviation ΔAPS. That is, the accelerator opening deviation ΔAPS is compared with the acceleration threshold value APS1 (APS1 is a preset positive value) to determine the accelerator opening deviation ΔAPS.
If S is equal to or greater than the acceleration threshold APS1 (that is, ΔAPS ≧ AP
S1), it is determined that the engine is accelerating (step B56).

If it is determined in step B24 that the engine is not accelerating, the process proceeds to step B26 to calculate the engine speed deviation ΔNe. This engine speed deviation ΔNe
Is obtained by subtracting the engine speed detected in the previous sampling cycle or some cycles before from the engine speed detected this time. Next, the routine proceeds to step B28, where it is determined whether or not the engine is accelerating based on the engine speed deviation ΔNe. That is,
This engine speed deviation ΔNe is used as the acceleration threshold ΔNe1 (Δ
Ne1 is a preset positive value), and if the engine speed deviation ΔNe is equal to or greater than the acceleration threshold ΔNe1 (that is,
ΔNe ≧ ΔNe1), and it is determined that the engine is accelerating (step B56).

If both steps B24 and B28 are No, it is determined that the engine is not accelerating (step B58). Further, in the acceleration determination routine shown in FIG. 13, first, in step B30, it is determined whether or not the flag F1 is 0. This flag F1 is 1 during acceleration,
When not accelerating, it is set to 0, and the initial value is set to 0.

When the flag F1 is 0, that is, when the vehicle is not accelerating, the routine proceeds to step B32, where the accelerator opening deviation ΔAPS is calculated. This accelerator opening deviation ΔAP
S is obtained by subtracting the accelerator opening detected in the previous sampling cycle or some previous sampling cycles from the accelerator opening detected this time. Next, the routine proceeds to step B34, where it is determined whether or not the engine has started acceleration based on the accelerator opening deviation ΔAPS. That is,
This accelerator opening deviation ΔCCS is used as the acceleration start determination threshold ΔA.
Compared with PS1 (ΔAPS1 >> 0), the accelerator opening deviation ΔAPS is greater than or equal to a threshold value ΔAPS1 (that is, ΔAPS ≧ Δ).
If it is APS1), it is determined that the engine has started acceleration (step B36), the flag F1 is set to 1, and to that effect,
That is, a signal indicating that the engine is accelerating is output (step B38).

On the contrary, the accelerator opening deviation ΔCCS is equal to the threshold value Δ.
If it is less than APS1 (that is, ΔAPS <ΔAPS1), the process proceeds to step B54, the flag F1 is held at 0, and a signal to this effect, that is, the engine is not accelerating is output. When it is determined in step B36 that the acceleration is started, the process proceeds from step B30 to step B40 in the next control cycle, and the accelerator opening deviation ΔAP is resumed.
Calculate S. This accelerator opening deviation ΔAPS is obtained by subtracting the accelerator opening detected in the previous sampling cycle or several cycles before from the accelerator opening detected this time, as in the case of step B32.

Next, the routine proceeds to step B42, where it is judged based on the accelerator opening deviation ΔAPS whether or not the engine has finished acceleration. In other words, this accelerator opening deviation Δ
The acceleration end determination threshold value ΔAPS2 (ΔAPS2 ≦ 0
Or ΔAPS2≈0), the accelerator opening deviation Δ
APS is less than or equal to the threshold value ΔAPS2 (that is, ΔAPS ≦ ΔAP
If S2), it is determined that the engine has finished accelerating (step B52), the flag F1 is set to 0, and a signal to this effect, that is, the engine is not accelerating is output (step B54).

Of course, after the start of acceleration, the accelerator opening deviation ΔA
If PS does not fall below the threshold ΔAPS2 (that is, ΔA
PS> ΔAPS2), Step B42 to Step B3
In step 8, the flag F1 is held at 1, and a signal indicating this, that is, the engine is accelerating is output. Even in this way, it is possible to determine the end of acceleration.

Also, an acceleration determination routine as shown in FIG. 14 can be considered. In this acceleration determination, as shown in FIG. 13, the accelerator opening deviation ΔAPS is calculated in step B32, and the accelerator opening deviation ΔA is calculated in step B34.
Although PS is compared with the acceleration start determination threshold ΔAPS1 to determine the start of acceleration, the end of acceleration is determined based on the accelerator opening APS itself, as shown in step B45.

That is, in step B45, the accelerator opening APS is set to the acceleration end determination threshold APS relating to the accelerator opening.
1 (APS << 100% or APS≈0), the accelerator opening APS is equal to or less than the threshold APS1 (that is, APS ≦
If it is APS1), it is determined that the engine has finished acceleration (step B52), the flag F1 is set to 0, and to that effect,
That is, a signal indicating that the engine is not accelerated is output (step B54).

This is because, in general, the accelerator opening APS is returned to a small state when the acceleration is finished, and this is the focus of attention. Of course, after the start of acceleration, if the accelerator opening APS does not become equal to or less than the threshold value APS1 (that is, APS ≦ APS1), the routine proceeds from step B46 to step B38, the flag F1 is held at 1, and this effect, that is, the engine A signal indicating that the vehicle is accelerating is output.

Also in this way, it is possible to determine the end of acceleration. Further, an acceleration determination routine as shown in FIG. 15 can be considered. In this acceleration determination, as shown in FIG. 13, the accelerator opening deviation ΔAPS is calculated in step B32, and the accelerator opening deviation ΔA is calculated in step B34.
The start of acceleration is determined by comparing PS with the acceleration start determination threshold value ΔAPS1, but the end of acceleration is determined in step B44,
As shown in S46, the engine speed deviation ΔNe is calculated, and the calculation is performed based on the engine speed deviation ΔNe.

That is, in step B44, as in the accelerator opening deviation ΔAPS, the engine speed detected in the previous sampling cycle or some cycles before is subtracted from the engine speed detected this time. The engine speed deviation ΔNe is obtained. Then step B
46, the engine speed deviation ΔNe is compared with the acceleration end determination threshold ΔNe1 (ΔNe1≈0), and the engine speed deviation ΔNe is equal to or less than the threshold ΔNe1 (that is, ΔNe ≦
If ΔNe1), it is determined that the engine has finished acceleration (step B52), the flag F1 is set to 0, and to that effect,
That is, a signal indicating that the engine is not accelerated is output (step B54).

Of course, after acceleration starts, the engine speed deviation Δ
If Ne does not fall below the threshold ΔNe1 (that is, ΔNe
> ΔNe1), the process proceeds from step B46 to step B38, the flag F1 is held at 1, and a signal indicating this, that is, the engine is accelerating is output. Even in this way, it is possible to determine the end of acceleration.

Next, the supercharged internal combustion engine with the exhaust gas recirculation control device of the fifth embodiment will be explained. In the fifth embodiment, the first connecting passage 8 and the second connecting passage 18 are the same as in the fourth embodiment. In the fourth embodiment, the exhaust gas is always recirculated by either the first EGR or the second EGR, whereas in the present embodiment, in the EGR prohibition region. The exhaust gas recirculation is stopped without operating either the first EGR or the second EGR.
When it is not in the R prohibition region, either the first EGR or the second EGR is operated to recirculate the exhaust gas. In other words, if it is not in the EGR prohibited area,
The first EGR through the first connecting passage 8 during engine acceleration
The second EGR route by the second connecting passage 18 is selected except when the route is selected and the engine is accelerated.

Therefore, the exhaust gas recirculation control of the fifth embodiment
In a supercharged internal combustion engine with a device, as shown in FIG.
Gas recirculation control and bypass passage switching control are performed. One
That is, as shown in FIG. 16, the accelerator opening APS,
Information of gin rotation speed Ne and cooling water temperature WT at a predetermined cycle
Imported from each sensor (step B10),
Determine whether the operating condition is in the EGR prohibition range
(Step B14). Specifically, the cooling water temperature WT
Set value WT set for₀(Eg WT₀= 70 ° C)
Below, or a setting in which the engine speed Ne is set in advance
Value Ne ₀(Eg Ne₀= 3000 rpm) or higher, or
Accelerator opening APS is a preset value APS
₀(For example, APS₀= 60%) or more, EGR
This is a prohibited area, and in other cases, the first connection passage 8
Alternatively, the EGR region in which the EGR is performed by the second connecting passage 18
Becomes

If it is not the EGR prohibited area, step B2
The process proceeds to 0 and acceleration judgment is performed. There are various forms of the acceleration determination step as described above, but if it is determined that the vehicle is accelerating, the process proceeds from step B60 to step B70 to exhaust the gas using the first connecting passage 8. Perform gas recirculation. Since Steps B70 to B100 are the same as those in the fourth embodiment, their description will be omitted.

On the other hand, if the vehicle is not accelerating, step B60
From step B110 to the second EGR valve 1
Exhaust gas recirculation is carried out using 9. Step B110
Since step B180 is the same as in the fourth embodiment, its description is omitted. On the other hand, if the EGR prohibition region is set in step B14, the process proceeds to step B16 to issue the EGR prohibition command, and further the process proceeds to step B130 to set the flag F to 1
If the flag F is 1, the process proceeds from step B130 to step B140, the timer value T is started to be counted by a timer (not shown), and then,
The process proceeds to step B150, and the flag F is set to 0.

Then, the process proceeds to step B160, where it is determined whether the timer value T has reached a preset value T ₁ . In the control cycle just after switching from the EGR area to the EGR prohibition area, the timer has just started and the timer value T
Since the set value T ₁ has not reached the set value T ₁ , the current control cycle is ended without changing the state of the switching valve 11, that is, with the bypass passage 11 side open state.

If the state of the EGR prohibition region or the state of not being in the EGR prohibition region but not accelerating continues, from the next control cycle, through steps B10, B14, B16, or steps B10, B14, B20, B60, B11.
0, B120, step B130 to step B1
Perform each step of 80. That is, step B170
Then, the timer value T is incremented by a value t corresponding to the control cycle, and if the timer value T does not reach the set value T ₁ , the state of the directional control valve 11 is left in the bypass passage 11 side open state and the current control cycle is set. is terminated, is continued for a time state of the EGR prohibited area or during acceleration in accordance with the set value T _1, in the step B160 is determined that the timer value T reaches the set value T _1, the process proceeds to step B180.

Then, in step B180, the switching valve 11
The state is set to the open state on the intercooler 10 side, and the supply air is circulated to the intercooler 10. Next, a description will be given of a supercharged internal combustion engine with an exhaust gas recirculation control device according to a sixth embodiment. In this embodiment, as shown in FIG. 17, the first connection passage 8 and the first connection passage 8 are provided as in the fourth and fifth embodiments. In addition to having two EGR routes with the second connection passage 18, the exhaust gas recirculation passage (connection passage) in the intake passage 2 is provided as in the second embodiment.
In the portion immediately upstream of the compressor 6 downstream of the opening of 8,
Intake air temperature sensor 1 as means for detecting engine operating condition
4 is provided so that the temperature of the intake air flowing into the compressor 6 can be detected. The intake air temperature sensor 14 is connected to the ECU 13, and the information on the intake air temperature flowing into the compressor 6 is taken into the ECU 13.

As a result, the ECU 13 determines that the exhaust gas recirculation by the first connecting passage 8 is not performed (first
The case where the intake air temperature Tt flowing into the compressor 6 is equal to or higher than a preset Tt ₀ is added as an EGR prohibition region). That is, in this embodiment, the first EGR
The prohibited area is the set value WT in which the cooling water temperature WT is preset.
₀ (for example, WT ₀ = 70 ° C.) or less, or a set value Ne ₀ (for example, Ne ₀ ) in which the engine speed Ne is set in advance.
= 3000 rpm) or more, or a preset value APS ₀ (for example, APS ₀ = 60) in which the accelerator opening APS is preset.
%) Or more, or the intake air temperature T flowing into the compressor 6
It is set when t is equal to or higher than a preset temperature Tt ₀ .

In this way, the target of the intake air temperature Tt as the first EGR prohibition region is the same as in the second embodiment.
This is to reliably avoid damage to the compressor 6 due to heat. Further, in the device of the present embodiment, the determination of the end of acceleration is made based on the accelerator opening APS and the vehicle speed deviation ΔV. That is, the vehicle speed deviation ΔV is calculated based on the vehicle speed V detected by the vehicle speed detection sensor 24, and the accelerator opening APS returns to almost 0% during acceleration (APS ≦ APS).
1: APS1≈0) or the vehicle speed deviation ΔV is a predetermined value Δ
When V1 (ΔV1≈0) or less (ΔV <ΔV1), it is determined that the end of acceleration is determined. Or
Instead, the accelerator pedal opening APS is almost 0% during acceleration.
Or (APS ≦ APS1: APS1≈0), or
When the vehicle speed deviation ΔV has a negative value (ΔV <0), it may be determined that the end of acceleration is determined.

Therefore, in the supercharged internal combustion engine with the exhaust gas recirculation control device of the sixth embodiment, the exhaust gas recirculation control and the bypass passage switching control are performed as shown in FIG.
As shown in 9, acceleration judgment is performed. That is, in the exhaust gas recirculation control and the bypass passage switching control, as shown in FIG. 18, the determination of the first EGR prohibition is different from that in the fourth embodiment.
First, in step B11, the accelerator opening APS,
The intake air temperature Tt flowing into the compressor 6 is taken in addition to the engine speed Ne and the cooling water temperature WT. Then, in the first EGR prohibition determination in step B13, the determination is performed in consideration of the intake air temperature Tt flowing into the compressor 6 as well.

That is, the cooling water temperature WT is equal to or lower than the preset value WT ₀ (for example, WT ₀ = 70 ° C.), or the engine speed Ne is preset to the preset value Ne ₀ (for example, Ne ₀ = 3000 rpm). Or above, or accelerator opening A
PS is a preset value APS ₀ (for example, APS ₀
= 60%) or more, and also when the intake air temperature Tt flowing into the compressor 6 is equal to or more than a preset Tt ₀ ,
It is determined that the first EGR is prohibited. Since the other control procedures are the same as those in the fourth embodiment, the description thereof will be omitted.

As described above, in this embodiment, even when the intake air temperature Tt flowing into the compressor 6 becomes equal to or higher than the set temperature Tt ₀ , the exhaust gas recirculation is prohibited and the high temperature exhaust gas flows into the intake air. Since it disappears, the compressor 6 will not be exposed to high temperatures. As a result, even if the compressor 6 is made of a material that does not have particularly high heat resistance, the compressor 6 will not be damaged by heat.

Also, in this embodiment, various effects similar to those of the fourth embodiment can be obtained. Then, in the acceleration determination, as shown in FIG. 19, it is determined in step B30 whether the flag F1 is 0. If the flag F1 is 0, the process proceeds to step B32 to calculate the accelerator opening deviation ΔAPS, In step B34, the accelerator opening deviation ΔAPS is compared with the acceleration start determination threshold ΔAPS1 to determine whether the engine has started acceleration. Accelerator opening deviation ΔAPS
Is greater than or equal to the threshold value ΔAPS1 (that is, ΔAPS ≧ ΔAPS1)
If so, it is determined that the engine has started acceleration (step B36), and the flag F1 is set to 1 (step B38).
If the accelerator opening deviation ΔCCS is less than the threshold value ΔAPS1 (that is, ΔAPS <ΔAPS1), the process proceeds to step B54 and the flag F1 is held at 0.

When the acceleration start is determined, in the next control cycle, the routine proceeds from step B30 to step B39, where the accelerator opening APS is set to the acceleration end determination threshold APS1 (APS1
≈0) to determine whether the engine has finished accelerating. The accelerator opening APS is almost 0 (that is, APS ≦
If it is APS1), it is determined that the engine has finished acceleration (step B52).

On the other hand, if the accelerator pedal opening APS is not substantially 0 (that is, APS≤APS1), the routine proceeds to step B41, where the vehicle speed deviation ΔV is calculated, and then step B43.
And the vehicle speed deviation ΔV is set to the acceleration end determination threshold ΔV1 (Δ
It is determined whether the engine has finished acceleration by comparing with V1≈0). The vehicle speed deviation ΔV is equal to or less than the threshold value ΔV1 (that is, Δ
When V1 ≦ ΔV1), it is determined that the engine has finished acceleration (step B52).

When it is judged that the engine has finished accelerating, the flag F1 is set to 0, and a signal to this effect, that is, a signal indicating that the engine is not accelerating is output (step B5).
4). Of course, after starting acceleration, the accelerator opening APS is almost 0.
If the vehicle speed deviation ΔV does not reach the threshold value ΔV1 or less, the process proceeds from step B43 to step B38, the flag F1 is held at 1, and a signal to this effect, that is, the engine is accelerating is output. .

The acceleration end is determined by the accelerator opening A
The accelerator opening deviation ΔAPS and the vehicle speed deviation Δ are used by using the accelerator opening deviation ΔAPS instead of the PS itself.
You may make it based on V and. That is, the accelerator opening deviation ΔAPS is equal to or less than the threshold ΔAPS2 (that is, ΔAPS2).
When APS ≦ ΔAPS2) or the vehicle speed deviation ΔV becomes equal to or less than the threshold value ΔV1 (that is, ΔV ≦ ΔV1), it is determined that the engine has finished acceleration. Alternatively, the acceleration end determination may be performed based on the accelerator opening APS, the accelerator opening deviation ΔAPS, and the vehicle speed deviation ΔV.

In the acceleration determination, the vehicle speed deviation ΔV may be used for both the acceleration start determination and the acceleration end determination. For example, as shown in FIG. 20, in step B30, it is determined whether or not the flag F1 is 0. If the flag F1 is 0, the process proceeds to step B33, the vehicle speed deviation ΔV is calculated, and then the process proceeds to step B35. The vehicle speed deviation ΔV is compared with the acceleration start determination threshold ΔV2 (ΔV2 >> 0) to determine whether the engine has started acceleration. If the vehicle speed deviation ΔV is greater than or equal to the threshold value ΔV2 (that is, ΔV ≧ ΔV2), it is determined that the engine has started acceleration (step B36), and the flag F1 is set to 1 (step B38). If the vehicle speed deviation ΔV is less than the threshold value ΔV2 (that is, ΔV <ΔV2), step B
The process proceeds to 54 and holds the flag F1 at 0.

When the start of acceleration is determined, in the next control cycle, the process advances from step B30 to step B41 to calculate the vehicle speed deviation ΔV, and then to step B43, the vehicle speed deviation ΔV is set to the acceleration end determination threshold value ΔV1 ( It is determined whether the engine has finished acceleration by comparing with ΔV1≈0).
The vehicle speed deviation ΔV is less than or equal to the threshold value ΔV1 (that is, ΔV ≦ ΔV1)
If it becomes, it is determined that the engine has finished acceleration (step B52).

When it is judged that the engine has finished accelerating, the flag F1 is set to 0 and a signal to this effect, that is, a signal indicating that the engine is not accelerating is output (step B5).
4). Of course, if the vehicle speed deviation ΔV does not fall below the threshold value ΔV1 after the start of acceleration, the steps B43 to B38 are performed.
Then, the flag F1 is held at 1 and
It outputs a signal that the engine is accelerating.

When the engine accelerates, the vehicle accelerates accordingly. Therefore, even if the vehicle speed deviation is used for both the determination of the start and the end of the acceleration of the engine,
It is possible to make a reliable determination. Further, also in the sixth embodiment, as in the fifth embodiment, the EGR prohibition region is provided based on the operating state of the engine, and in the EGR prohibition region, neither the first EGR nor the second EGR is operated and the exhaust gas is exhausted. The gas recirculation is stopped, and when it is not in the EGR prohibition region, one of the first EGR and the second EGR is operated to recirculate the exhaust gas, and the intake air temperature Tt flowing into the compressor 6 is reduced. In consideration of the above, the EGR prohibition determination may be performed, or the above-described acceleration end determination may be used.

Next, the supercharged internal combustion engine with the exhaust gas recirculation control device of the seventh embodiment will be described. In this embodiment, as shown in FIG. 21, the intake air temperature sensor 14 is provided as in the sixth embodiment. Provided, the first EGR prohibited area or EGR
The intake air temperature Tt flowing into the compressor 6 is also added to the determination of the prohibited area. In addition, in the present embodiment, the determination of the end of acceleration of the engine is performed by determining the supercharging pressure deviation ΔP.
It is designed to be judged by _AI .

For this reason, the present apparatus is provided with the pressure sensor 20 on the downstream side of the compressor 6 in the intake passage 2 so that the boost pressure can be detected. Also, E
The CU 13 has a function of calculating the deviation ΔP _{AI of the} supercharging pressure detected by the pressure sensor 20, and the calculated supercharging pressure deviation ΔP _AI.
Is compared with the acceleration end determination threshold ΔP _AI 1, and the boost pressure deviation Δ
If P _AI becomes smaller than the acceleration end determination threshold value ΔP _AI 1, the function of determining acceleration end is provided. The acceleration end determination threshold value ΔP _AI 1 is set to 0 or a value close to 0.

Therefore, in the supercharged internal combustion engine with the exhaust gas recirculation control device according to the seventh embodiment, the acceleration determination is performed as shown in FIG. That is, as shown in FIG. 22, it is determined in step B30 whether the flag F1 is 0, and the flag F1
If 1 is 0, the routine proceeds to step B32, where the accelerator opening deviation ΔAPS is calculated, and then the routine proceeds to step B34 where the accelerator opening deviation ΔAPS is set to the acceleration start determination threshold ΔA.
Compared with PS1, it is determined whether the engine has started acceleration. Accelerator deviation ΔAPS is threshold ΔAPS1
If the above, it is determined that the engine has started acceleration (step B36), and the flag F1 is set to 1 (step B3).
8). If the accelerator opening deviation ΔCCS is less than the threshold value ΔAPS1 (that is, ΔAPS <ΔAPS1), step B54.
Then, the process proceeds to and the flag F1 is held at 0.

[0178] When the acceleration start is determined, in the next control cycle, the routine proceeds from step B30 to step B46, calculates supercharging pressure deviation [Delta] P _AI, In step B48, the supercharging pressure deviation [Delta] P _AI Acceleration end determination threshold ΔP _AI 1 (ΔP _AI
1≈0) to determine whether the engine has finished accelerating. The supercharging pressure deviation ΔP _{AI is} almost 0 (that is, ΔP _AI <
If ΔP _AI 1), it is determined that the engine has finished acceleration (step B52). Then, the flag F1 is set to 0, and a signal indicating this, that is, the engine is not accelerating is output (step B54).

On the other hand, the supercharging pressure deviation ΔP _{AI is} almost 0 (that is,
If ΔP _AI <ΔP _AI 1) is not satisfied, the process proceeds from step B48 to step B38, the flag F1 is held at 1, and a signal indicating this, that is, the engine is accelerating is output (step B38). As described above, in the present device, the end of acceleration of the engine is detected by the deviation of the boost pressure. However, since the end of the acceleration of the engine coincides with the end of the increase of the boost pressure, it is possible to accurately determine the end of the acceleration. There is.

In addition, in the acceleration judgment, the acceleration start judgment
The supercharging pressure deviation ΔP is also used to determine the end of acceleration. _AITo use
May be. For example, as shown in FIG. 23, step B30
Determines whether the flag F1 is 0, and the flag F1 is not 0.
If so, proceed to Step B37 and change the supercharging pressure deviation ΔP._AICalculate
Then, the process proceeds to step B39, where the supercharging pressure deviation ΔP
_AIIs the acceleration start determination threshold ΔP_AI2 (ΔP_AICompare with 2 >> 0)
Then, it is determined whether the engine has started acceleration. car
The speed deviation ΔV is greater than or equal to the threshold value ΔV2 (that is, ΔV ≧ ΔV2).
Determine that the engine has started acceleration, and the flag F1
Is set to 1 (step B38). Vehicle speed deviation ΔV is threshold Δ
If less than V2 (that is, ΔV <ΔV2), step B54
Then, the process proceeds to and the flag F1 is held at 0.

[0181] When the acceleration start is determined, in the next control cycle, the routine proceeds from step B30 to step B46, calculates supercharging pressure deviation [Delta] P _AI, In step B48, the supercharging pressure deviation [Delta] P _AI Acceleration end determination threshold ΔP _AI 1 (ΔP _AI
1≈0) to determine whether the engine has finished accelerating. The supercharging pressure deviation ΔP _{AI is} almost 0 (that is, ΔP _AI <
If ΔP _AI 1), it is determined that the engine has finished acceleration (step B52). Then, the flag F1 is set to 0, and a signal indicating this, that is, the engine is not accelerating is output (step B54).

On the other hand, the supercharging pressure deviation ΔP _{AI is} almost 0 (that is,
If ΔP _AI <ΔP _AI 1) is not satisfied, the process proceeds from step B48 to step B38, the flag F1 is held at 1, and a signal indicating this, that is, the engine is accelerating is output (step B38). Since the start and the end of the acceleration of the engine coincide with the start and the end of the increase of the supercharging pressure, there is an advantage that the end of the acceleration can be accurately determined even in such a case.

Also in the seventh embodiment, as in the fifth embodiment, the EGR prohibition region is provided based on the operating condition of the engine, and the first EGR and the second EGR region are provided in the EGR prohibition region.
Recirculation of the exhaust gas is stopped without operating any of the EGR, and when the EGR is not in the prohibition region, one of the first EGR and the second EGR is operated to recirculate the exhaust gas. In the above, it may be possible to make the EGR prohibition determination in consideration of the intake air temperature Tt flowing into the compressor 6 or to use the acceleration end determination as described above.

Next, a supercharged internal combustion engine with an exhaust gas recirculation control device according to the eighth embodiment will be described. FIG. 24 is a schematic diagram showing an intake / exhaust route of this engine, and FIG. 10 (fourth embodiment). The same reference numerals as in FIG. This embodiment has two EGR routes of the first connection passage 8 and the second connection passage 18 as in the fourth embodiment, and the exhaust gas recirculation passage in the intake passage 2 is the same as in the third embodiment. An intake throttle valve 15A is provided upstream of the opening of the (connection passage) 8. Then, by restricting the intake throttle valve 15A, the introduction of fresh air from the intake passage 2 is suppressed, and the pressure difference between the upstream and downstream of the exhaust gas recirculation passage 8 is increased. This is to solve this problem because it is difficult to increase the exhaust gas recirculation amount (EGR gas amount) in the exhaust gas recirculation passage 8 as in the third embodiment.

The intake throttle valve 15A can adjust the opening degree (that is, the degree of throttle), and the opening degree adjustment is performed together with the opening degree adjustment of the on-off valve 9. Here, when a large exhaust gas recirculation amount is not required, the intake throttle valve 15A is not throttled, and the exhaust gas recirculation amount is adjusted by adjusting the opening degree of only the on-off valve 9, and a large exhaust gas return amount equal to or greater than a predetermined value is adjusted. When the flow rate is required, the opening / closing valve 9 is adjusted while the intake throttle valve 15A is throttled to adjust the exhaust gas recirculation amount.

That is, if the required exhaust gas recirculation amount is less than the predetermined value, the ECU 13 fully opens the intake throttle valve 15A and makes a request based on the accelerator opening APS, the engine speed Ne, and the cooling water temperature WT. The target EGR lift amount is calculated so as to realize the exhaust gas recirculation amount, and the target opening degree (target EGR lift amount) of the opening / closing valve 9 is set, and the opening degree of the opening / closing valve 9 is adjusted according to the target EGR lift amount. It is supposed to do.

If the required exhaust gas recirculation amount is equal to or larger than a predetermined value, the ECU 13 realizes the required exhaust gas recirculation amount based on the accelerator opening APS, the engine speed Ne, and the cooling water temperature WT. Then, the target throttle amount of the intake throttle valve 15A and the target EGR lift amount of the on-off valve 9 are set, and the opening amounts of the intake throttle valve 15A and the on-off valve 9 are adjusted according to these target throttle amount and target EGR lift amount.

Further, the ECU 13 further corrects the target EGR lift amount when the engine is accelerated or decelerated with respect to the target throttle amount and the target EGR lift amount, as in the first embodiment. A drive command is issued to the open / close valve (EGR valve) 9 based on the amount. In the present embodiment, the other configurations are the same as those in the fourth embodiment, and the other control by the ECU 13 is also performed in the same manner as in the fifth embodiment.

Since the supercharged internal combustion engine with the exhaust gas recirculation control device according to the eighth embodiment of the present invention is constructed as described above, the exhaust gas recirculation control and the bypass passage switching control are shown in FIG. Is done as follows. In FIG. 25,
The same steps as those in the fourth embodiment (FIG. 11) show the same control contents, and therefore the description thereof will be omitted, and only the differences from the fourth embodiment will be described. In this embodiment, when performing the first EGR by the exhaust gas recirculation passage 8, in step B72 corresponding to step B70 in the fourth embodiment, based on each information of the accelerator opening APS, the engine speed Ne, and the cooling water temperature WT. Then, the target EGR lift amount for the EGR valve 9 and the target throttle amount of the intake throttle valve 15A are set. In this case, when the required exhaust gas recirculation amount is less than the predetermined value and the target EGR lift amount is less than the predetermined value, the intake throttle valve 15A is fully opened and throttle control is not performed. When the target EGR lift amount is not less than the predetermined value and not less than the predetermined value, the target throttle amount of the intake throttle valve 15A is set.

Then, in the following step B82, the target EG
The EGR valve 9 is driven based on the R lift amount, and the intake throttle valve 15A is driven based on the target throttle amount. By controlling the intake throttle valve 15A in this manner, the intake passage 2
It is possible to increase the pressure difference between the upstream and downstream sides of the exhaust gas recirculation passage 8 while suppressing the introduction of fresh air from the inside of the exhaust gas recirculation passage 8 to lower the pressure on the downstream side of the exhaust gas recirculation passage 8. There is an effect that can be increased.

As shown in FIG. 26, the intake throttle valve 1
An exhaust throttle valve 15B may be provided in place of 5A and the exhaust throttle valve 15B may be controlled in the same manner as. Also,
As in the fifth embodiment, E
A GR prohibition area is provided, and in the EGR prohibition area, the first E
The exhaust gas recirculation is stopped without operating either the GR or the second EGR.
In a system in which either the EGR or the second EGR is operated to recirculate exhaust gas, an intake throttle valve 15A or an exhaust throttle valve 15B is provided to control the EGR lift amount and to reduce the intake throttle The throttle control of the valve 15A or the exhaust throttle valve 15B may be performed.

The first connecting passage 8 is the same as in the fourth embodiment.
In the case where two EGR routes of the exhaust gas and the second connection passage 18 are provided, as shown in FIG. 27, a filter 16 is provided in the middle of the exhaust gas recirculation passage 8 and particulates in the exhaust gas recirculated. The matter may be trapped and the clean exhaust gas may be recirculated so as to return to the intake passage 2. In this case, the risk of contamination or clogging of the intercooler 10 due to exhaust gas recirculation is reduced, but by using the bypass passage 11 that bypasses the intercooler 10, the contamination or clogging of the intercooler 10 can be prevented more reliably.

Further, as in the fourth embodiment, the first connecting passage 8
In the case where two EGR routes of the exhaust gas recirculation passage 8 and the second connection passage 18 are provided, as shown in FIG. 28, a cooler (heat exchanger) 17 is provided in the middle of the exhaust gas recirculation passage 8 to recirculate the exhaust gas. The exhaust gas may be cooled in advance. In this case, since the intake air temperature flowing into the compressor 6 is lowered, the compressor 6 is not exposed to a high temperature,
Even if the compressor 6 is formed of a material that does not have particularly high heat resistance, there is an advantage that the compressor 6 is not damaged by heat.

[0194]

As described above in detail, according to the supercharged internal combustion engine with exhaust gas recirculation control device of the present invention as set forth in claim 1, it is provided in the exhaust passage of the internal combustion engine and is driven by the flow of exhaust gas. A supercharger including a turbine and a compressor driven by the turbine and provided in the intake passage of the internal combustion engine; and a supercharger provided in the intake passage downstream of the compressor and supercharged by the compressor. A cooler for supply air to be cooled, and one end of which is connected to a portion of the intake passage on the upstream side of the cooler and the other end of which is connected to a portion of the intake passage on the downstream side of the cooler. A bypass passage bypassing the bypass passage, a switching valve provided at a branch portion between the bypass passage and the intake passage, for switching the intake air to either the cooler side or the bypass passage side, An operating state detecting means for detecting an operating state of the fuel engine; an exhaust gas recirculation passage having a connecting passage connecting a downstream side of the turbine in the exhaust passage and an upstream side of the compressor in the intake passage; An on-off valve that opens and closes the connection passage, and controls the opening and closing of the on-off valve so that the connection passage recirculates exhaust gas when the internal combustion engine is in a predetermined operating region based on detection information from the operating state detection means. In addition, when the internal combustion engine is in a predetermined operating region, the exhaust gas is directed to the intake passage side by the control means for controlling the switching valve so that the bypass passage side is opened when the connection passage is opened. The recirculation reduces NOx in the exhaust gas, and in particular, the exhaust gas after driving the turbine is recirculated to the intake passage, so that the energy of the exhaust gas is reduced. By making full use of it, the exhaust gas can be recirculated while reliably driving the turbine, and it is possible to secure supercharging pressure and take full advantage of the supercharger, contributing to engine performance improvement. .

Furthermore, since the temperature of the exhaust gas after driving the turbine is lowered, the exhaust gas having a lowered temperature is recirculated to the intake passage, and the exhaust gas having such a low temperature is recirculated and recirculated. By ensuring the supercharging pressure, the equivalence ratio of the fresh air and the recirculated exhaust gas in the intake passage increases, and it becomes easier to supply a sufficient amount of air into the engine, so that the combustion of the engine is performed in a more complete combustion state. As a result, the output of the engine is secured, and the generation of particulate matter due to combustion is suppressed, so that exhaust gas purification can be promoted, which also contributes to the improvement of engine performance.

At the same time, the intake air passes through the bypass passage side that bypasses the cooler, but since the intake air bypasses the cooler in this way, the exhaust gas does not flow through the cooler. The clogging and damage of the cooler are prevented, the reliability of the cooler is improved, and the output improvement effect of the engine by the cooler is surely obtained. Claim 2
According to the supercharged internal combustion engine with an exhaust gas recirculation control device of the present invention described above, in the configuration according to claim 1, the control means is configured to operate the internal combustion engine based on the detection information from the operating state detection means. In an operating region other than the predetermined operating region, the on-off valve is closed to stop the recirculation of the exhaust gas, and the switching valve is opened on the cooler side after a predetermined period has passed since the on-off valve was closed. When it is necessary to secure the output of the engine and suppress the generation of particulate matter in the exhaust gas rather than the reduction of NOx in the exhaust gas by the configuration of controlling to the state in which the exhaust gas recirculates. In addition, it is possible to secure the output of the engine and suppress the generation of particulate matter. Further, it is possible to shift to a state in which the cooler is used while surely avoiding mixing of particulate matter in the exhaust gas due to exhaust gas recirculation to the intake air, and after opening the cooler side, through the cooler While cooling the intake air, there is also an effect that the intake charge efficiency can be increased and the output of the engine can be improved.

According to the supercharged internal combustion engine with an exhaust gas recirculation control device of the present invention as defined in claim 3, in the configuration as defined in claim 1 or 2, the control means detects the information detected by the operating state detection means. Based on the above, when the internal combustion engine is decelerating, the opening / closing valve is controlled to be opened / closed in order to correct the exhaust gas recirculation amount to the reduction amount side, so that the exhaust gas recirculation amount is reduced during deceleration. Therefore, even when decelerating, the excess air ratio does not decrease, and even if the vehicle accelerates again from deceleration or shifts from deceleration to steady operation, the excess air ratio is secured and the engine output is secured. Therefore, there is an advantage that the increase of particulate matter in the exhaust gas can be surely suppressed and the exhaust gas purification can be promoted.

According to the supercharged internal combustion engine with an exhaust gas recirculation control device of the present invention as defined in claim 4, in the configuration of claim 3, the operating state detecting means artificially operates the internal combustion engine. The accelerator opening detection means for detecting the accelerator opening for, the control means, the reduction rate of the accelerator opening based on the detection information from the accelerator opening detection means is a preset value or more When the internal combustion engine is judged to be decelerating when, it is possible to quickly reduce the exhaust gas recirculation amount from the start of deceleration, and to re-accelerate from deceleration or transition from deceleration to steady operation. ,
The increase of particulate matter in the exhaust gas can be reliably suppressed, and the exhaust gas purification can be promoted.

According to the supercharged internal combustion engine with an exhaust gas recirculation control device of the present invention as defined in claim 5, in the configuration of claim 3, the operating state detecting means detects the rotational speed of the internal combustion engine. A rotation speed detection means, and the control means,
When the deceleration of the internal combustion engine is judged to be in deceleration when the decreasing speed of the rotation speed of the internal combustion engine is equal to or more than a preset value based on the detection information from the rotational speed detecting means, It has become possible to reliably execute control to reduce the exhaust gas recirculation amount, and when deceleration and re-acceleration or deceleration to steady operation are performed, the increase in particulate matter in the exhaust gas is reliably suppressed and exhaust gas purification Can be promoted.

According to the supercharged internal combustion engine with an exhaust gas recirculation control device of the present invention as defined in claim 6, in the structure of claim 1, the exhaust gas recirculation passage is located downstream of the turbine in the exhaust passage. Side and a first connection passage that connects the intake passage with an upstream side of the compressor, and an upstream side of the exhaust passage with respect to the turbine and a downstream side of the intake passage with respect to the intake cooler. A second opening / closing valve for opening / closing the first connecting passage and a second opening / closing valve for opening / closing the second connecting passage are provided, and the exhaust gas is recirculated while exhaust gas is exhausted. The turbine can be reliably driven by the gas, and the exhaust gas can be recirculated without lowering the supercharging pressure by the supercharger, ensuring the engine output and purifying the exhaust gas by reducing NOx. It is possible to achieve both. Further, when the exhaust gas is recirculated using the first connection passage, even if the exhaust gas is recirculated, the compressor is not affected by heat of the exhaust gas. Exhaust gas can be purified.

According to the supercharged internal combustion engine with an exhaust gas recirculation control device of the present invention as defined in claim 7, in the configuration as defined in claim 6, the control means is based on the detection information from the operating state detection means. When the internal combustion engine is accelerating in the predetermined operating range, the first opening / closing valve is opened and the second opening / closing valve is closed, and the switching valve is opened to the bypass passage side. Control, when the internal combustion engine has finished accelerating in the predetermined operating region based on the detection information from the operating state detecting means, closes the first opening / closing valve and opens the second opening / closing valve, In addition, by controlling the switching valve so that the cooler side is opened, NOx reduction by exhaust gas recirculation and securing of engine output by supercharging and reduction of particulate matter in exhaust gas are both achieved. In addition to being able to improve the performance of the engine, it is possible to avoid dirt and clogging of the cooler due to particulate matter, it is possible to improve the reliability of the cooler, and to improve the output power of the engine by the cooler. You will definitely get it. In addition, the exhaust gas can be recirculated while protecting the compressor.

According to the supercharged internal combustion engine with an exhaust gas recirculation control device of the present invention as set forth in claim 8, in the configuration of claim 7, the operating state detecting means artificially operates the internal combustion engine. The accelerator opening detection means for detecting the accelerator opening for, the control means, based on the detection information from the accelerator opening detection means, the increase rate of the accelerator opening is a preset opening When the internal combustion engine has started acceleration when the speed becomes equal to or higher than the increase speed set value, and thereafter, when the accelerator opening becomes equal to or smaller than a preset opening set value, the internal combustion engine ends acceleration. With the configuration for making the determination, the first opening / closing valve, the second opening / closing valve, and the switching valve can be quickly switched at the start of acceleration and at the end of acceleration, thereby improving the engine output and exhaust gas required at the time of acceleration. N by reflux It is possible to achieve both the x reduction efficiently.

According to the supercharged internal combustion engine with an exhaust gas recirculation control device of the present invention as defined in claim 9, in the configuration of claim 7, the internal combustion engine is mounted on a vehicle, and the operating state detecting means comprises: A first detecting means for detecting the speed of the vehicle, wherein the control means presets an increasing speed of the speed of the vehicle based on the detection information from the speed detecting means;
It is determined that the internal combustion engine is accelerating when it is equal to or higher than the increase speed set value, and thereafter, the increase speed of the speed of the vehicle is set as a value smaller than the first increase speed set value in advance. 2 When the internal combustion engine is judged to have finished accelerating when it becomes equal to or less than the increase speed set value, the first opening / closing valve, the second opening / closing valve and the switching valve are promptly operated at the start of acceleration and the end of acceleration. It is possible to switch between NO and NO due to the improvement of engine output and exhaust gas recirculation required during acceleration.
x reduction can be efficiently achieved at the same time.

According to the supercharged internal combustion engine with an exhaust gas recirculation control device of the present invention as set forth in claim 10, in the structure of claim 7, the operating state detecting means detects the supercharging pressure. The control means has a detection means, and the control means accelerates the internal combustion engine based on the detection information from the supercharging pressure detection means when the increasing speed of the supercharging pressure is equal to or higher than a preset first set value. It is determined that the internal combustion engine has finished acceleration when the supercharging pressure becomes equal to or less than a second preset value which is preset as a value smaller than the first preset value. With such a configuration, it is possible to reliably determine that the engine is accelerating, and it is possible to efficiently achieve both improvement in engine output required during acceleration and reduction of NOx due to exhaust gas recirculation.

According to the supercharged internal combustion engine with an exhaust gas recirculation control device of the present invention as set forth in claim 11, in the configuration of claim 7, the operating state detecting means detects the rotational speed of the internal combustion engine. The control means has a rotation speed detection means, and after the acceleration determination of the internal combustion engine, the set value in which the increase speed of the rotation speed of the internal combustion engine is preset based on the detection information from the rotation speed detection means. With the configuration in which it is determined that the internal combustion engine has finished accelerating when the following occurs, it is possible to reliably determine that the engine is accelerating, and improve the engine output and exhaust gas required during acceleration. It is possible to efficiently achieve both NOx reduction by reflux.

According to the supercharged internal combustion engine with an exhaust gas recirculation control device of the present invention as defined in claim 12, in the structure according to any one of claims 1 through 11, one of the intake passage and the exhaust passage is provided. On the other hand, a passage throttle means for narrowing the passage area is provided, and the control means controls the opening and closing of the passage throttle means to control the exhaust gas recirculation amount.
The differential pressure between the upstream side and the downstream side of the exhaust gas recirculation passage can be increased, exhaust gas recirculation can be promoted, and exhaust gas purification by reducing NOx in the exhaust gas can be promoted.

According to the supercharged internal combustion engine with an exhaust gas recirculation control device of the present invention as set forth in claim 13, in the structure of claim 12, the passage throttle means is connected to the connection passage of the intake passage. With the configuration that an intake throttle valve is provided on the upstream side of the section, the differential pressure between the upstream side and the downstream side of the exhaust gas recirculation passage can be reliably increased, and exhaust gas recirculation can be promoted. Exhaust gas purification by reducing NOx in the inside can be promoted.

According to the supercharged internal combustion engine with an exhaust gas recirculation control device of the present invention as set forth in claim 14, in the structure of claim 13, the intake air is provided in a portion of the intake passage upstream of the compressor. With a structure that has a pressure detecting means for detecting the pressure inside the passage, and the control means controls the opening and closing of the intake throttle valve to control the exhaust gas recirculation amount according to the detection information of the pressure detecting means. The pressure difference between the upstream side and the downstream side of the exhaust gas recirculation passage can be increased as necessary, the exhaust gas recirculation can be promoted, and the exhaust gas purification by reducing NOx in the exhaust gas can be promoted. .

According to the supercharged internal combustion engine with an exhaust gas recirculation control device of the present invention as defined in claim 15, in the structure of claim 12, the passage throttle means is connected to the connection passage of the intake passage. With the configuration that the exhaust throttle valve is provided on the downstream side of the section, the differential pressure between the upstream side and the downstream side of the exhaust gas recirculation passage can be reliably increased, and the exhaust gas recirculation can be promoted. Exhaust gas purification by reducing NOx in the inside can be promoted.

According to the supercharged internal combustion engine with an exhaust gas recirculation control device of the present invention according to claim 16, in the structure according to claim 15, the exhaust passage is provided at a portion of the exhaust passage on the downstream side of the exhaust turbine. A configuration in which a pressure detection unit that detects the pressure inside the exhaust passage is provided, and the control unit controls the opening and closing of the intake throttle valve to control the exhaust gas recirculation amount according to the detection information of the pressure detection unit. This allows the differential pressure between the upstream side and the downstream side of the exhaust gas recirculation passage to be increased as necessary,
The exhaust gas recirculation can be promoted, and N in the exhaust gas
It is possible to promote exhaust gas purification by reducing Ox.

According to the supercharged internal combustion engine with an exhaust gas recirculation control device of the present invention as set forth in claim 17, in the configuration according to any one of claims 1 to 16, the connection passage of the exhaust gas recirculation passage is provided. With the structure that the exhaust gas cooling means for cooling the exhaust gas is provided, even if the recirculation exhaust gas flows into the compressor, the compressor is not heated by the exhaust gas even if the exhaust gas is recirculated, and the exhaust gas is exhausted. It is possible to obtain the NOx reduction effect by the exhaust gas recirculation while preventing damage to the charger due to heat.

According to the supercharged internal combustion engine with an exhaust gas recirculation control device of the present invention as set forth in claim 18, in the configuration according to any one of claims 1 to 17, the connection passage of the exhaust gas recirculation passage is provided. By the configuration in which a filter that collects particulates in the exhaust gas is interposed, particulate matter in the recirculated exhaust gas is removed, and even if the exhaust gas is circulated in the air supply cooler, The inside of the air supply cooler is prevented from being contaminated with particulate matter, and while the air supply cooler is protected, N by exhaust gas recirculation is provided.
Ox reduction effect can be obtained.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an intake system and an exhaust system of an internal combustion engine showing a supercharged internal combustion engine with an exhaust gas recirculation control device according to a first embodiment of the present invention.

FIG. 2 is a flowchart showing exhaust gas recirculation control in the supercharged internal combustion engine with the exhaust gas recirculation control device according to the first embodiment of the present invention.

FIG. 3 is a schematic configuration diagram of an intake system and an exhaust system of an internal combustion engine showing a supercharged internal combustion engine with an exhaust gas recirculation control device according to a second embodiment of the present invention.

FIG. 4 is a flow chart showing exhaust gas recirculation control in a supercharged internal combustion engine with an exhaust gas recirculation control device according to a second embodiment of the present invention.

FIG. 5 is a schematic configuration diagram of an intake system and an exhaust system of an internal combustion engine showing a supercharged internal combustion engine with an exhaust gas recirculation control device according to a third embodiment of the present invention.

FIG. 6 is a flow chart showing exhaust gas recirculation control in a supercharged internal combustion engine with an exhaust gas recirculation control device according to a third embodiment of the present invention.

FIG. 7 is a schematic configuration diagram of an intake system and an exhaust system of an internal combustion engine showing a modified example of a supercharged internal combustion engine with an exhaust gas recirculation control device according to a third embodiment of the present invention.

FIG. 8 is a schematic configuration diagram of an intake system and an exhaust system of an internal combustion engine showing a modified example of the supercharged internal combustion engine with the exhaust gas recirculation control device according to the first embodiment of the present invention.

FIG. 9 is a schematic configuration diagram of an intake system and an exhaust system of an internal combustion engine showing another modified example of the supercharged internal combustion engine with the exhaust gas recirculation control device according to the first embodiment of the present invention.

FIG. 10 is a schematic configuration diagram of an intake system and an exhaust system of an internal combustion engine showing a supercharged internal combustion engine with an exhaust gas recirculation control device according to a fourth embodiment of the present invention.

FIG. 11 is a flowchart showing exhaust gas recirculation control in a supercharged internal combustion engine with an exhaust gas recirculation control device according to a fourth embodiment of the present invention.

FIG. 12 is a flowchart according to a first embodiment of acceleration determination of exhaust gas recirculation control in a supercharged internal combustion engine with an exhaust gas recirculation control device according to a fourth embodiment of the present invention.

FIG. 13 is a flowchart according to a second embodiment of acceleration determination of exhaust gas recirculation control in a supercharged internal combustion engine with an exhaust gas recirculation control device according to a fourth embodiment of the present invention.

FIG. 14 is a flowchart according to a third embodiment of acceleration determination of exhaust gas recirculation control in a supercharged internal combustion engine with an exhaust gas recirculation control device according to a fourth embodiment of the present invention.

FIG. 15 is a flow chart according to a fourth embodiment of acceleration determination of exhaust gas recirculation control in a supercharged internal combustion engine with an exhaust gas recirculation control device according to the fourth embodiment of the present invention.

FIG. 16 is a flowchart showing exhaust gas recirculation control in a supercharged internal combustion engine with an exhaust gas recirculation control device according to a fifth embodiment of the present invention.

FIG. 17 is a schematic configuration diagram of an intake system and an exhaust system of an internal combustion engine showing a supercharged internal combustion engine with an exhaust gas recirculation control device according to a sixth embodiment of the present invention.

FIG. 18 is a flow chart showing exhaust gas recirculation control in a supercharged internal combustion engine with an exhaust gas recirculation control device according to a sixth embodiment of the present invention.

FIG. 19 is a flowchart according to a first embodiment of acceleration determination of exhaust gas recirculation control in a supercharged internal combustion engine with an exhaust gas recirculation control device according to a sixth embodiment of the present invention.

FIG. 20 is a flowchart according to a second embodiment of acceleration determination of exhaust gas recirculation control in a supercharged internal combustion engine with an exhaust gas recirculation control device according to a sixth embodiment of the present invention.

FIG. 21 is a schematic configuration diagram of an intake system and an exhaust system of an internal combustion engine showing a supercharged internal combustion engine with an exhaust gas recirculation control device according to a seventh embodiment of the present invention.

FIG. 22 is a flowchart according to a first embodiment of acceleration determination of exhaust gas recirculation control in a supercharged internal combustion engine with an exhaust gas recirculation control device according to a seventh embodiment of the present invention.

FIG. 23 is a flowchart according to a second embodiment of acceleration determination of exhaust gas recirculation control in a supercharged internal combustion engine with an exhaust gas recirculation control device according to a seventh embodiment of the present invention.

FIG. 24 is a schematic configuration diagram of an intake system and an exhaust system of an internal combustion engine showing a modified example of the supercharged internal combustion engine with an exhaust gas recirculation control device according to an eighth embodiment of the present invention.

FIG. 25 is a flow chart showing exhaust gas recirculation control in a supercharged internal combustion engine with an exhaust gas recirculation control device according to an eighth embodiment of the present invention.

FIG. 26 is a schematic configuration diagram of an intake system and an exhaust system of an internal combustion engine showing a modified example of the supercharged internal combustion engine with the exhaust gas recirculation control device according to the eighth embodiment of the present invention.

FIG. 27 is a schematic configuration diagram of an intake system and an exhaust system of an internal combustion engine showing another modified example of the supercharged internal combustion engine with an exhaust gas recirculation control device according to the fourth embodiment of the present invention.

FIG. 28 is a schematic configuration diagram of an intake system and an exhaust system of an internal combustion engine showing another modified example of the supercharged internal combustion engine with the exhaust gas recirculation control device of the fourth embodiment of the present invention.

FIG. 29 is a schematic configuration diagram of an intake system and an exhaust system of an internal combustion engine showing an example of a conventional supercharged internal combustion engine with an exhaust gas recirculation control device.

[Explanation of symbols]

1 Diesel engine body (engine) 2 Intake passage 3 Exhaust passage 4 Supercharger (turbocharger) 5 Turbine 6 Compressor 7 Exhaust gas recirculation device (EGR) 8 Exhaust gas recirculation passage (connection passage) 9 Open / close valve (EGR valve) 10 Air supply cooler (intercooler) 11 Bypass passage 12 Switching valve 13 Electronic control unit (ECU) 14 as control means 14 Air supply temperature sensor 15A as engine operating state detection means 15A Intake throttle valve 15B Exhaust throttle valve 16 Filter 17 Cooling Device (heat exchanger) 18 Second connection passage (exhaust gas recirculation passage) 19 Open / close valve (EGR valve) 20 Pressure sensor 21 Engine speed sensor as operating state detecting means 22 Accelerator opening sensor as operating state detecting means ( Accelerator opening detection means) 23 As an operating state detection means Temperature sensor 24 vehicle speed sensor

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI Technical display location F02D 9/02 S 9/04 DG 43/00 301 NP 45/00 314 EF F02M 25 / 07 550 R 570 GP 580 D

Claims (18)

[Claims] 1. A supercharger comprising a turbine provided in an exhaust passage of an internal combustion engine and driven by a flow of exhaust gas, a supercharger provided in an intake passage of the internal combustion engine and a compressor driven by the turbine, and the intake air. A supply air cooler provided downstream of the compressor in the passage for cooling the supply air supercharged by the compressor; and one end connected to a portion upstream of the cooler in the intake passage A bypass passage connected to a portion of the intake passage on the downstream side of the cooler to bypass the cooler; and a branch portion between the bypass passage and the intake passage,
A switching valve for switching the intake air to either the cooler side or the bypass passage side, an operating state detecting means for detecting an operating state of the internal combustion engine, and a turbine in the exhaust passage rather than the turbine. An exhaust gas recirculation passage having a connection passage that connects the downstream side and the upstream side of the compressor in the intake passage, an on-off valve that opens and closes the connection passage, and based on detection information from the operating state detection means, When the internal combustion engine is in a predetermined operating region, the connection passage controls the opening and closing of the on-off valve so as to recirculate exhaust gas,
A supercharged internal combustion engine with an exhaust gas recirculation control device, comprising control means for controlling the switching valve so that the bypass passage side is opened when the connection passage is opened. 2. The control means should stop the recirculation of the exhaust gas when the internal combustion engine is in an operating area other than the predetermined operating area based on the detection information from the operating state detecting means. The exhaust gas recirculation control device according to claim 1, wherein the switching valve is closed and the switching valve is controlled to be opened to the cooler side after a lapse of a predetermined period from the closing of the opening / closing valve. Feed type internal combustion engine. 3. The on-off valve, wherein the control means corrects the exhaust gas recirculation amount to a reduction side when the internal combustion engine is decelerating based on the detection information from the operating state detection means. 3. The supercharged internal combustion engine with an exhaust gas recirculation control device according to claim 1, wherein the opening / closing of the exhaust gas recirculation control device is controlled. 4. The operating state detecting means has an accelerator opening detecting means for detecting an accelerator opening for artificially operating the internal combustion engine, and the control means controls the accelerator opening detecting means from the accelerator opening detecting means. 4. The exhaust gas recirculation control according to claim 3, wherein it is determined that the internal combustion engine is decelerating when the rate of decrease of the accelerator opening is equal to or greater than a preset value based on the detection information of. Supercharged internal combustion engine with a device. 5. The operating state detecting means includes a rotating speed detecting means for detecting a rotating speed of the internal combustion engine, and the control means detects the rotating speed of the internal combustion engine on the basis of detection information from the rotating speed detecting means. The supercharged internal combustion engine with an exhaust gas recirculation control device according to claim 3, wherein the internal combustion engine is judged to be decelerating when the rotational speed reduction speed is equal to or higher than a preset set value. 6. The exhaust gas recirculation passage connects a downstream side of the exhaust passage with respect to the turbine and an upstream side of the intake passage with respect to the compressor, and a first connection passage in the exhaust passage from the turbine. Also has a second connecting passage connecting the upstream side and the downstream side of the intake cooler in the intake passage, and the second connecting passage is provided together with a first opening / closing valve for opening and closing the first connecting passage. The supercharged internal combustion engine with an exhaust gas recirculation control device according to claim 1, wherein a second on-off valve that opens and closes is provided. 7. The control means opens the first opening / closing valve and opens the first opening / closing valve when the internal combustion engine is accelerating in the predetermined operating range based on the detection information from the operating state detecting means. (2) The on-off valve is closed, and the switching valve is controlled so that the bypass passage side is opened, and based on the detection information from the operating state detecting means, the internal combustion engine ends acceleration in the predetermined operating region. 7. The exhaust gas according to claim 6, characterized in that, when it does, the first on-off valve is closed, the second on-off valve is opened, and the switching valve is controlled so that the cooler side is opened. Supercharged internal combustion engine with recirculation control device. 8. The operating state detecting means includes an accelerator opening detecting means for detecting an accelerator opening for artificially operating the internal combustion engine, and the control means controls the accelerator opening detecting means from the accelerator opening detecting means. Based on the detection information of, when the increasing speed of the accelerator opening becomes equal to or more than the preset opening increasing speed set value, it is determined that the internal combustion engine has started acceleration, and thereafter, the accelerator opening is The supercharged internal combustion engine with an exhaust gas recirculation control device according to claim 7, wherein it is determined that the internal combustion engine has finished accelerating when it becomes equal to or less than a preset opening set value. 9. The internal combustion engine is mounted on a vehicle, the operating state detecting means has speed detecting means for detecting the speed of the vehicle, and the control means is based on detection information from the speed detecting means. Then, it is determined that the internal combustion engine is accelerating when the speed increase rate of the vehicle is equal to or higher than a preset first increase speed set value, and thereafter, the speed increase rate of the vehicle is
The exhaust gas according to claim 7, wherein it is determined that the internal combustion engine has finished acceleration when the value becomes equal to or less than a second increase speed setting value that is preset as a value smaller than the first increase speed setting value. Supercharged internal combustion engine with recirculation control device. 10. The operating state detecting means has a supercharging pressure detecting means for detecting the supercharging pressure, and the control means, based on the detection information from the supercharging pressure detecting means, the supercharging pressure. When it is determined that the internal combustion engine is accelerating when the increasing speed is greater than or equal to a preset first preset value, and thereafter, the supercharging pressure is preset as a value smaller than the first preset value. It is determined that the internal combustion engine has finished accelerating when it becomes equal to or less than the second set value that has been set,
A supercharged internal combustion engine with an exhaust gas recirculation control device according to claim 7. 11. The operating state detection means includes a rotation speed detection means for detecting a rotation speed of the internal combustion engine, and the control means outputs the rotation speed detection means from the rotation speed detection means after determining an acceleration of the internal combustion engine. 8. The exhaust gas according to claim 7, wherein it is determined that the internal combustion engine has finished acceleration when the speed of increase of the rotation speed of the internal combustion engine becomes equal to or less than a preset set value based on the detection information. Supercharged internal combustion engine with gas recirculation control device. 12. A passage throttle means for narrowing a passage area is provided in one of the intake passage and the exhaust passage, and the control means opens and closes the passage throttle means to control the exhaust gas recirculation amount. It controls, It is characterized by the above-mentioned.
11. A supercharged internal combustion engine with an exhaust gas recirculation control device according to any one of 11 above. 13. The exhaust gas according to claim 12, wherein the passage throttle means has an intake throttle valve provided on an upstream side of a connection portion of the intake passage with the connection passage. Supercharged internal combustion engine with recirculation control device. 14. A pressure detecting means for detecting a pressure inside the intake passage, the pressure detecting means being provided in a portion of the intake passage on an upstream side of the compressor, wherein the control means responds to detection information of the pressure detecting means. 14. The supercharged internal combustion engine with an exhaust gas recirculation control device according to claim 13, wherein the intake throttle valve is controlled to be opened / closed to control the exhaust gas recirculation amount. 15. The exhaust gas according to claim 12, wherein the passage throttle means has an exhaust throttle valve provided on a downstream side of a connection portion of the intake passage with the connection passage. Supercharged internal combustion engine with recirculation control device. 16. A pressure detecting means is provided in a portion of the exhaust passage downstream of the exhaust turbine to detect a pressure inside the exhaust passage, and the control means uses the detection information of the pressure detecting means. 16. The supercharged internal combustion engine with an exhaust gas recirculation control device according to claim 15, wherein the exhaust throttle valve is controlled to be opened / closed so as to control the exhaust gas recirculation amount accordingly. 17. The connecting passage of the exhaust gas recirculation passage,
The supercharged internal combustion engine with an exhaust gas recirculation control device according to any one of claims 1 to 16, characterized in that an exhaust gas cooling means for cooling the exhaust gas is interposed. 18. The connecting passage of the exhaust gas recirculation passage,
A filter for collecting particulate matter in the exhaust gas is provided, and the filter is provided.
A supercharged internal combustion engine with an exhaust gas recirculation control device according to any one of 1.