JP2016050517A - Internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an internal combustion engine provided with an electric compressor, capable of preventing the excessive introduction of blow-by gas into an intake passage.SOLUTION: The internal combustion engine comprises: the electric compressor provided in the intake passage; a throttle valve provided upstream of the electric compressor in the intake passage; a blow-by gas introduction passage connected to the intake passage between the throttle valve and the electric compressor; and a control unit that controls the throttle valve and the electric compressor, and the control unit comprises means for detecting or estimating a pressure of the intake passage between the throttle valve and the electric compressor; and means for implementing a negative pressure control to control a reduction in the pressure of the intake passage by controlling at least either the throttle valve or the electric compressor if a request to actuate the electric compressor is generated and the pressure of the intake passage is lower than a predetermined value set in a negative pressure region.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an internal combustion engine, and more particularly to an internal combustion engine equipped with an electric compressor.

  Conventionally, for example, Patent Document 1 discloses an internal combustion engine including an electric compressor in an intake passage.

  Further, the internal combustion engine disclosed in Patent Document 1 is provided with a blow-by gas introduction passage that introduces exhaust gas and air-fuel mixture leaked into the crankcase (hereinafter referred to as blow-by gas) into the intake passage. By introducing the blow-by gas into the intake passage, the blow-by gas is mixed with the intake air and sucked into the combustion chamber for combustion processing. Thereby, it can suppress that blowby gas is discharged | emitted in air | atmosphere.

JP 2005-226505 A JP 2013-108479 A JP 2008-261257 A

  By the way, when the internal combustion engine disclosed in Patent Document 1 is decelerated, the intake valve is sealed by fully closing a throttle valve provided upstream of the electric compressor. If the electric compressor is operated at this time, the pressure in the intake passage becomes negative. Thereby, blow-by gas is excessively introduced into the intake passage. As a result, there is a possibility of affecting the reliability of the internal combustion engine, such as deterioration of combustion due to the influence of oil contained in the blow-by gas, and contamination of parts.

  The present invention has been made to solve the above-described problems, and an internal combustion engine that can prevent excessive introduction of blow-by gas into an intake passage in an internal combustion engine equipped with an electric compressor. The purpose is to provide.

In order to achieve the above object, a first invention is an internal combustion engine,
An electric compressor provided in the intake passage;
A throttle valve provided in an intake passage upstream of the electric compressor;
A blow-by gas introduction passage connected to an intake passage between the throttle valve and the electric compressor;
A control device for controlling the throttle valve and the electric compressor,
The controller is
Means for detecting or estimating the pressure in the intake passage between the throttle valve and the electric compressor;
When there is a request for operation of the electric compressor, if the pressure of the intake passage is less than a predetermined value set in a negative pressure region, by controlling at least one of the throttle valve and the electric compressor, Means for executing negative pressure suppression control for suppressing a decrease in pressure in the intake passage;
It is characterized by providing.

  According to a second aspect, in the first aspect, the means for executing the negative pressure suppression control prohibits the operation of the electric compressor.

  According to a third aspect, in the first aspect, the means for executing the negative pressure suppression control increases the opening of the throttle valve and operates the electric compressor.

  In a fourth aspect based on the first aspect, the means for executing the negative pressure suppression control changes the target rotational speed of the electric compressor so that the pressure in the intake passage does not fall below a lower limit value. It is characterized by.

According to a fifth invention, in any one of the first to fourth inventions,
A turbocharger having a turbine provided in the exhaust passage and a compressor provided in the intake passage;
An EGR device including an EGR passage connecting an exhaust passage downstream of the turbine and an intake passage upstream of the compressor, and an EGR valve provided in the EGR passage,
The said control apparatus is provided with the means to adjust the opening degree of the said EGR valve according to a driving | running state.

  According to the present invention, excessive introduction of blow-by gas into the intake passage can be suppressed. Since the blow-by gas contains oil, the present invention can prevent the oil from decreasing. Furthermore, it is possible to prevent the deterioration of combustion caused by the oil introduced into the combustion chamber and the contamination of the components of the combustion chamber.

1 is a schematic configuration diagram for explaining a configuration of a system according to a first embodiment. It is a figure showing the flow of the gas of the intake passage in the upstream of a compressor. FIG. 3 is a diagram illustrating a relationship between a compressor pre-pressure and an intake air amount when the first throttle valve of Embodiment 1 is fully opened or fully closed. It is a figure showing the relationship between blow-by gas amount and compressor pre-pressure. It is a figure showing the flow of the gas of the intake passage in the upstream of a compressor. It is a figure showing each EGR area | region. 3 is a flowchart showing a routine for determining execution of negative pressure suppression control according to the first embodiment. 2 is a diagram illustrating a timing chart of Embodiment 1. FIG. 6 is a flowchart showing a routine for determining execution of negative pressure suppression control according to the second embodiment. FIG. 10 is a diagram illustrating a timing chart of the second embodiment. It is a figure showing the modification of the negative pressure suppression control of Embodiment 2. FIG. 10 is a flowchart illustrating a negative pressure suppression control routine according to a third embodiment. 10 is a diagram illustrating a timing chart of Embodiment 3. FIG.

Embodiment 1 FIG.
FIG. 1 is a schematic configuration diagram for explaining a configuration of a system according to the first embodiment. The system shown in FIG. 1 includes an engine 10. The engine 10 is a supercharged diesel engine with an EGR device.

  In the first embodiment, a turbocharger that uses exhaust gas to compress intake air is employed as a supercharger. The supercharger has a structure in which a compressor 22 provided in the intake passage 26 and a turbine 32 provided in the exhaust passage 35 are connected via an axis.

  Further, the engine 10 includes an electric compressor 18 that compresses intake air. The intake passage 26 is provided with a bypass passage 20 that bypasses the electric compressor 18. A bypass valve 21 is provided in the bypass passage 20.

  An intake passage 26 is connected to the combustion chamber 50 of the engine 10. The intake passage 26 includes an air cleaner 14 at the inlet thereof. A first throttle valve 12, an electric compressor 18, and a compressor 22 are provided downstream of the air cleaner 14 in this order. An intercooler 24 and a second throttle valve 27 are provided downstream of the compressor 22.

  Here, the first throttle valve 12 is provided to adjust the pressure of the intake passage 26 upstream of the compressor 22. The second throttle valve 27 is provided downstream of the intercooler 24.

  Next, the flow of intake air in the intake passage 26 will be described. The intake air is drawn from the air cleaner 14 and then passes through the first throttle valve 12. The intake air that has passed through the first throttle valve 12 passes through the bypass passage 20 when the bypass valve 21 is open, and is compressed by the electric compressor 18 when the bypass valve 21 is closed. The Thereafter, the intake air that has passed through the bypass passage 20 or the electric compressor 18 is compressed by the compressor 22 and then cooled by the intercooler 24. The intake air cooled by the intercooler 24 is taken into the combustion chamber 50 of the engine 10.

  An exhaust passage 35 is connected to the combustion chamber 50 of the engine 10. A turbine 32 and a catalyst 34 are provided in the exhaust passage 35 toward the downstream from the combustion chamber 50. The turbine 32 is rotated by the exhaust from the combustion chamber 50. When the turbine 32 rotates, the compressor 22 rotates through the shaft, and supercharging is performed.

  Next, the EGR device will be described. The engine 10 of the first embodiment is provided with two types of EGR devices. Hereinafter, two types of EGR devices will be described.

  The first EGR device is an EGR device (hereinafter referred to as an HPL-EGR device) that returns the exhaust gas immediately after being discharged from the combustion chamber 50 to the intake passage 26 between the combustion chamber 50 and the intercooler 24. The HPL-EGR device includes an HPL-EGR passage 30 that connects an intake passage 26 downstream of the first throttle valve 12 and an exhaust passage 35 upstream of the turbine 32, and an HPL-EGR valve 28 provided in the HPL-EGR passage 30. Including.

  The second EGR device is a device that returns the exhaust gas in the exhaust passage 35 downstream from the catalyst 34 to the intake passage 26 upstream from the compressor 22 (hereinafter referred to as an LPL-EGR device). The LPL-EGR device includes an LPL-EGR passage 40, an EGR cooler 36, and an LPL-EGR valve 38. The LPL-EGR passage 40 is provided so that the exhaust passage 35 downstream of the catalyst 34 is an inlet and the intake passage 26 upstream of the compressor 22 is an outlet. The EGR gas is compressed by the compressor 22 together with the intake air from the air cleaner 14 because the outlet of the LPL-EGR passage 40 is upstream of the compressor 22. Further, the outlet of the LPL-EGR passage 40 is connected to the intake passage 26 upstream of the electric compressor 18.

  The engine 10 is provided with a blow-by gas introduction passage 42. The blow-by gas introduction passage 42 connects the intake passage 26 between the first throttle valve 12 and the electric compressor 18 and the crankcase of the engine 10. The blow-by gas introduction passage 42 is not provided with a valve for controlling the introduction of blow-by gas.

  A pressure sensor 16 for grasping the operating state of the intake passage 26 is attached to the intake passage 26. The pressure sensor 16 detects the pressure in the intake passage 26 between the first throttle valve 12 and the electric compressor 18. Hereinafter, the pressure detected by the pressure sensor 16 is also expressed as a pre-compressor pressure. Instead of the pressure sensor 16, numerical values such as the opening degree of the LPL-EGR valve 38, the opening degree of the first throttle valve 12, the rotational speed of the compressor 22, and the amount of gas passing through the air flow meter (fresh air amount) are used. A method of estimating the compressor pre-pressure based on a physical model used as a parameter may be used.

  The configuration of the system of the first embodiment includes an ECU 100 (Electric Control Unit) that controls the operating state of the engine 10. A pressure sensor 16 is connected to the input side of the ECU 100. ECU 100 detects the pre-compressor pressure from the signal output from pressure sensor 16.

  On the other hand, actuators such as an HPL-EGR valve 28, an LPL-EGR valve 38, a first throttle valve 12, and an electric compressor 18 are connected to the output side of the ECU 100. The ECU 100 outputs signals for operating various actuators according to the operating state. For example, the ECU 100 adjusts the opening degree of at least one of the HPL-EGR valve 28 and the LPL-EGR valve 38 in order to supply a target EGR amount. The ECU 100 operates the opening of the first throttle valve 12 to adjust the compressor pre-pressure. ECU 100 outputs a signal for operating electric compressor 18 in accordance with the operating state.

  In the intake passage 26 upstream of the compressor 22, blow-by gas and EGR gas are introduced by controlling the opening of the first throttle valve 12. This will be described with reference to FIG.

  FIG. 2 is a diagram showing the gas flow in the intake passage 26 upstream of the compressor 22. The arrows in FIG. 2 indicate the flow of gas passing through the intake passage 26. FIG. 2 shows a state in which the bypass valve 21 is opened and gas flows through the bypass passage 20. At this time, the opening degree of the first throttle valve 12 is smaller than full open. This is to make the intake passage 26 upstream of the compressor 22 have a negative pressure. Thereby, blow-by gas can be introduced from the blow-by gas introduction passage 42 and EGR gas can be introduced from the LPL-EGR passage 40 to the intake passage 26.

  Hereinafter, how the compressor pre-pressure changes depending on the opening of the first throttle valve 12 will be described with reference to FIG.

  FIG. 3 is a diagram showing the relationship between the compressor pre-pressure and the intake air amount when the first throttle valve 12 of the first embodiment is fully opened or fully closed. As shown in FIG. 3, the compressor pre-pressure increases as the intake air amount increases. Furthermore, the compressor pre-pressure tends to be negative when the first throttle valve 12 is fully closed compared to when the first throttle valve 12 is fully open. This is because if the first throttle valve 12 is fully closed, the inside of the intake passage 26 is sealed and a negative pressure is likely to occur.

  FIG. 4 is a diagram showing the relationship between the blow-by gas amount and the compressor pre-pressure. FIG. 4 shows how the blow-by gas amount increases as the negative pressure of the compressor pre-pressure increases.

  As can be seen from FIGS. 3 and 4, if the opening of the first throttle valve 12 is reduced and the negative pressure of the compressor pre-pressure is increased in order to introduce EGR gas from the LPL-EGR device, the amount of blow-by gas increases. I understand that.

  By the way, when the opening degree of the first throttle valve 12 is reduced, blow-by gas may be excessively introduced when the electric compressor 18 is operated. This will be described with reference to FIG.

  FIG. 5 is a diagram showing the gas flow in the intake passage 26 upstream of the compressor 22. When the electric compressor 18 operates, the negative pressure in the intake passage 26 upstream of the compressor 22 increases. Thereby, blow-by gas from the blow-by gas introduction passage 42 and EGR gas from the LPL-EGR passage 40 may be excessively introduced into the intake passage 26.

  The excessive introduction of the blow-by gas is caused when EGR gas is introduced from the LPL-EGR apparatus. This will be described below with reference to FIG.

  FIG. 6 is a diagram showing each EGR region. FIG. 6 shows LPL-EGR and HPL-EGR usage areas for each operation area of the engine 10. FIG. 6 shows a state in which the HPL-EGR is switched to the LPL-EGR as the torque and the engine rotational speed are increased and the required air amount is increased. In the region where LPL-EGR is used, the opening of the first throttle valve 12 is reduced in order to make the pressure in the intake passage 26 smaller than the exhaust passage 35.

  Here, the amount of EGR gas introduced into the intake passage 26 can be suppressed by controlling the opening degree of the LPL-EGR valve 38. However, the amount of blow-by gas introduced into the intake passage 26 cannot be suppressed because the blow-by gas introduction passage 42 is not provided with a valve.

  The blow-by gas contains oil flowing through the engine 10. For this reason, when the blowby gas is excessively introduced into the intake passage 26, the oil easily decreases. Further, the deterioration of combustion due to the oil contained in the blow-by gas flowing into the combustion chamber 50 and the contamination of the intake passage 26 and parts in the combustion chamber 50 may be caused.

  Therefore, in the first embodiment, when there is an operation request while the electric compressor 18 is stopped, negative pressure suppression control is performed to control the electric compressor 18 to prevent excessive introduction of blow-by gas. Hereinafter, the specific content of the negative pressure suppression control will be described with reference to FIG.

  FIG. 7 is a flowchart showing a routine for determining execution of negative pressure suppression control according to the first embodiment. The ECU 100 has a memory for storing this routine. The ECU 100 has a processor for executing the stored routine.

  First, the ECU 100 detects an operating state (S100). In step S100, the ECU 100 detects the current operating state based on parameters such as engine speed and torque. Then, the ECU 100 determines whether or not there is an operation request for the electric compressor 18 based on the operating state detected in S100 (S102). The operation request of the electric compressor 18 includes a case where turbo lag of the supercharger is predicted to occur or a case where rapid acceleration is required. When it is determined that there is no operation request for the electric compressor 18, the ECU 100 executes normal control (S110). The normal control is control of the first throttle valve 12 and operation control of the electric compressor 18 for introducing LPL-EGR, and is executed in a routine different from this routine. Here, since it is determined in S102 that there is no request for operating the electric compressor 18, the electric compressor 18 does not operate. Thereafter, this routine ends.

  On the other hand, when it is determined in S102 that there is a request for operating the electric compressor 18, the ECU 100 detects the pre-compressor pressure by the pressure sensor 16 (S104).

  Next, the ECU 100 determines whether or not the pressure detected in S104 is smaller than a predetermined value (S106). When ECU 100 determines that the pressure detected in S104 is equal to or greater than a predetermined value, ECU 100 performs normal control (S110). Here, since it is determined in S102 that there is a request for operating the electric compressor 18, the electric compressor 18 operates. Thereafter, this routine ends. Here, the predetermined value is a value that is predicted to cause the compressor pre-pressure to be below a lower limit value described later when the electric compressor 18 is operated.

  On the other hand, when it is determined in S106 that the pressure detected in S104 is smaller than the predetermined value, the ECU 100 executes negative pressure suppression control and prohibits the operation of the electric compressor 18 (S108). As described above, in this routine, when both the determinations in S102 and S106 are YES, negative pressure suppression control for prohibiting the operation of the electric compressor 18 is performed although there is a request for the operation of the electric compressor 18. Thereby, excessive introduction of blow-by gas can be prevented. Thereafter, this routine ends.

  FIG. 8 is a diagram illustrating a timing chart of the first embodiment. In FIG. 8, the broken line is a change when the normal pressure control is performed without executing the negative pressure suppression control, and the solid line is a change when the negative pressure suppression control of the first embodiment is executed.

  FIG. 8A shows a change in the rotational speed of the electric compressor 18. As indicated by the solid line, when the negative pressure suppression control of the first embodiment is executed, the operation of the electric compressor 18 is prohibited. For this reason, the rotational speed of the electric compressor 18 does not increase.

  FIG. 8B shows changes in the compressor pre-pressure. As indicated by the solid line, when the negative pressure suppression control of the first embodiment is executed, the operation of the electric compressor 18 is prohibited, so the negative pressure of the compressor pre-pressure does not increase. On the other hand, when the normal control is followed, the pre-compressor pressure falls below the lower limit value indicated by the alternate long and short dash line in FIG. The lower limit value is a value corresponding to an upper limit value that serves as an index for excessive introduction of blow-by gas. If the compressor pre-pressure falls below the lower limit, blow-by gas may be excessively introduced.

  FIG. 8C shows a change in the opening degree of the first throttle valve 12. In the first embodiment, since the negative pressure suppression control is for controlling the electric compressor 18, the opening of the first throttle valve 12 does not change.

  FIG. 8D shows a change in the amount of blow-by gas introduced into the intake passage 26. When the negative pressure suppression control is executed, the operation of the electric compressor 18 is prohibited, so that the blow-by gas amount does not increase. On the other hand, when the normal control is followed, the upper limit value indicating excessive introduction of the blow-by gas amount is exceeded.

  As shown in FIG. 8D, the negative pressure suppression control of the first embodiment is performed, so that the pressure in the intake passage 26 can be suppressed from decreasing, and excessive introduction of blow-by gas can be suppressed. . As a result, a decrease in oil can be prevented. Further, it is possible to prevent deterioration of combustion due to the influence of oil and contamination of parts of the combustion chamber 50.

  In the system configuration of the first embodiment, the electric compressor and the turbocharger are provided in series in the engine, but the present invention is not limited to this. For example, the engine may be provided with only an electric compressor without providing a turbocharger. Moreover, the compressor of the supercharger and the electric compressor may be provided in parallel. The electric compressor may be configured as a motor-assisted turbo compressor. This modification can be similarly applied to Embodiments 2 and 3 to be described later.

  In the first embodiment, the ECU 100 executes the above S104, so that the “means for detecting or estimating the pressure of the intake passage” in the first invention is YES in S102, and The determination is YES, and thereafter, by executing S108, the “means for performing negative pressure suppression control” in the second aspect of the present invention is realized.

Embodiment 2. FIG.
In the second embodiment, in the negative pressure suppression control, the electric compressor 18 is operated similarly to the normal control, and the opening degree of the first throttle valve 12 is further increased. Hereinafter, the difference from the first embodiment will be mainly described with reference to FIGS. 9 and 10.

  FIG. 9 is a flowchart showing a routine for determining execution of negative pressure suppression control according to the second embodiment. Since S200, S202, S204, and S206 are the same controls as those in the first embodiment, description thereof is omitted.

  On the other hand, if the ECU 100 determines in S206 that the pressure detected in S204 is lower than the predetermined value, the negative pressure suppression control is executed to calculate the target opening of the first throttle valve 12 (S208). Specifically, the ECU 100 sets the opening degree of the first throttle valve 12 to be large. The opening set at this time is set to an opening at which the compressor pre-pressure does not fall below the lower limit value even when the electric compressor 18 is operated. As a result, it is possible to avoid the sealed state of the intake passage 26 when the opening of the first throttle valve 12 is small, and to prevent the compressor pre-pressure from becoming a negative pressure.

  Next, the ECU 100 corrects the current opening of the first throttle valve 12 so as to be the target opening of the first throttle valve 12 calculated in S208 as negative pressure suppression control (S210).

  Next, the ECU 100 operates the electric compressor 18 as negative pressure suppression control (S212). Thereafter, this routine ends.

  FIG. 10 is a diagram illustrating a timing chart of the second embodiment. In FIG. 10, the broken line is a change when the normal control is performed without executing the negative pressure suppression control, and the solid line is the negative pressure suppression control of the second embodiment.

  FIG. 10A shows a change in the rotational speed of the electric compressor 18. In the negative pressure suppression control of the second embodiment, the electric compressor 18 is operated. For this reason, as shown to Fig.10 (a), even if negative pressure suppression control is performed, the rotational speed of the electric compressor 18 rises similarly to the case where normal control is followed.

  FIG. 10B shows changes in the compressor pre-pressure. When the negative pressure suppression control of the second embodiment is executed, the compressor pre-pressure increases after the first throttle valve 12 is opened, and decreases when the electric compressor 18 is operated. Thus, when the negative pressure suppression control of the second embodiment is performed, it is possible to prevent the pre-compressor pressure from becoming lower than the lower limit value.

  FIG. 10C shows a change in the opening degree of the first throttle valve 12. In the negative pressure suppression control of the second embodiment, the opening degree of the first throttle valve 12 is increased. Here, in FIG. 10 (c), the opening degree of the first throttle valve 12 is increased before the electric compressor 18 is operated. This is to prevent the excessive introduction of blow-by gas first. This is control that opens the first throttle valve 12, and is not limited to this. For example, the opening degree of the first throttle valve 12 may be increased simultaneously with the operation of the electric compressor 18.

  FIG. 10D shows a change in the amount of blow-by gas introduced into the intake passage 26. The amount of blow-by gas decreases as the opening of the throttle valve 12 increases, and increases when the electric compressor 18 operates. Thus, if the negative pressure suppression control of Embodiment 2 is performed, the amount of blow-by gas can be suppressed as compared with the normal control.

  FIG. 11 is a diagram illustrating a modified example of the negative pressure suppression control according to the second embodiment. In FIG. 11 (c), the opening of the first throttle valve 12 is controlled to be smaller than that in FIG. 10 (c). FIG. 11B shows that the compressor pre-pressure is not below the lower limit value. Thus, the opening degree of the first throttle valve 12 may be set without the compressor pre-pressure falling below the lower limit value.

  In the second embodiment, the “means for executing negative pressure suppression control” in the third aspect of the present invention is realized by the ECU 100 executing the above steps S208, S210, and S212.

Embodiment 3 FIG.
In the third embodiment, the rotation speed of the electric compressor 18 is controlled in the negative pressure suppression control. Hereinafter, the difference from the first embodiment will be mainly described with reference to FIGS.

  FIG. 12 is a flowchart showing a negative pressure suppression control routine according to the third embodiment. Since S300, S302, and S304 are the same controls as those in the first embodiment, description thereof is omitted.

  After detecting the compressor pre-pressure in S304, the ECU 100 calculates the target rotational speed of the electric compressor 18 as negative pressure suppression control (S306). Specifically, the rotational speed of the electric compressor 18 is calculated so that the compressor pre-pressure does not fall below the lower limit value.

  Next, the ECU 100 operates the electric compressor 18 according to the target rotational speed calculated in S306 as negative pressure suppression control (S308). Thereafter, this routine ends.

  FIG. 13 is a diagram illustrating a timing chart of the third embodiment. In FIG. 13, the broken line is a change when the normal control is performed without executing the negative pressure suppression control, and the solid line is the negative pressure suppression control of the third embodiment.

  FIG. 13A shows the change in the rotational speed of the electric compressor 18. In the normal control, a target rotational speed corresponding to the content of the operation request for the electric compressor 18 is calculated. On the other hand, when the negative pressure suppression control of the third embodiment is executed, the target rotational speed of the electric compressor 18 is calculated and rewritten so that the compressor pre-pressure does not fall below the lower limit value. For this reason, when negative pressure suppression control is performed, the rotational speed of the electric compressor 18 becomes low compared with the case where normal control is followed.

  FIG. 13B shows a change in pressure in the intake passage. In the negative pressure suppression control of the third embodiment, as described in FIG. 13A, in the negative pressure suppression control, the rotational speed of the electric compressor 18 is set lower than that in the normal control. For this reason, when the negative pressure suppression control is executed, the compressor pre-pressure does not fall below the lower limit value.

  FIG. 13C shows a change in the opening degree of the first throttle valve 12. The opening degree of the first throttle valve 12 does not change in the negative pressure suppression control and the normal control.

  FIG. 13D shows a change in the amount of blow-by gas introduced into the intake passage. As shown in FIG. 11D, when the negative pressure suppression control of the third embodiment is executed, the blow-by gas amount is suppressed so as not to exceed the upper limit value.

  In the third embodiment, the ECU 100 implements “means for performing negative pressure suppression control” according to the fourth aspect of the present invention by executing S306 and S308.

10 Engine 12 Throttle valve 16 Pressure sensor 18 Electric compressor 22 Compressor 26 Intake passage 32 Turbine 42 Blow-by gas introduction passage

Claims (5)

An electric compressor provided in the intake passage;
A throttle valve provided in an intake passage upstream of the electric compressor;
A blow-by gas introduction passage connected to an intake passage between the throttle valve and the electric compressor;
A control device for controlling the throttle valve and the electric compressor,
The controller is
Means for detecting or estimating the pressure in the intake passage between the throttle valve and the electric compressor;
When there is a request for operation of the electric compressor, if the pressure of the intake passage is less than a predetermined value set in a negative pressure region, by controlling at least one of the throttle valve and the electric compressor, Means for executing negative pressure suppression control for suppressing a decrease in pressure in the intake passage;
An internal combustion engine comprising:   The internal combustion engine according to claim 1, wherein the means for performing the negative pressure suppression control prohibits the operation of the electric compressor.   2. The internal combustion engine according to claim 1, wherein the means for executing the negative pressure suppression control increases the opening of the throttle valve and operates the electric compressor.   2. The internal combustion engine according to claim 1, wherein the means for executing the negative pressure suppression control changes a target rotational speed of the electric compressor so that a pressure in the intake passage does not fall below a lower limit value. A turbocharger having a turbine provided in the exhaust passage and a compressor provided in the intake passage;
An EGR device including an EGR passage connecting an exhaust passage downstream of the turbine and an intake passage upstream of the compressor, and an EGR valve provided in the EGR passage,
The internal combustion engine according to any one of claims 1 to 4, wherein the control device includes means for adjusting an opening of the EGR valve in accordance with an operating state.

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