WO2017111080A1

WO2017111080A1 - Engine control device

Info

Publication number: WO2017111080A1
Application number: PCT/JP2016/088484
Authority: WO
Inventors: 幸司秦; 村田　真一
Original assignee: 三菱自動車工業株式会社
Priority date: 2015-12-25
Filing date: 2016-12-22
Publication date: 2017-06-29
Also published as: JP2017115766A; JP6672784B2

Abstract

An engine (1) is provided with an exhaust turbine (12) disposed in an exhaust passage (14), a mechanical supercharger (10) provided to an intake passage (4), an electrical supercharger (30) which is disposed in the intake passage (4) and supercharges air drawn into a combustion chamber, an exhaust bypass valve (42) for opening and closing an exhaust bypass passage (41) that connects the upstream and downstream sides of the exhaust turbine (12), and an intake bypass valve (34) for opening and closing an intake bypass passage (33) that connects the upstream and downstream sides of the electrical supercharger (30) in the intake passage (4). An ECU (50) is provided with a determination unit (55) for determining the operation of the electrical supercharger (30). When the operation of the electrical supercharger (30) has been determined, the electrical supercharger (30) is operated after the exhaust bypass valve (42) is opened and the intake bypass valve (34) is then closed.

Description

Engine control device

TECHNICAL FIELD The present invention relates to an engine control device including an electric supercharger that supercharges intake air with an electric motor and a mechanical supercharger that recovers exhaust gas energy by a turbine and supercharges intake air.

Engines equipped with a mechanical supercharger that supercharges intake air introduced into the combustion chamber using the energy of exhaust gas are widely used.

This type of mechanical supercharger, also called a turbocharger, is configured by arranging a compressor in the middle of the intake passage of the engine, placing a turbine in the middle of the exhaust passage, and rotating the turbine with exhaust gas flowing through the exhaust passage. The compressor is operated to increase the amount of intake air into the combustion chamber to improve the engine torque.

In recent years, various types of electric superchargers have been proposed in which the compressor is driven by an electric motor in addition to the supercharger using the energy of the exhaust gas. The electric supercharger has an advantage that it can be supercharged arbitrarily by supplying electric power regardless of the operating state of the engine (see, for example, Patent Document 1 below).

Also, the mechanical supercharger that uses the energy of exhaust gas employs a waste gate valve that adjusts the amount of inflow into the turbine by diverting a part of the exhaust gas. The supercharging pressure of intake air can be controlled by adjusting the amount of exhaust gas passing through the turbine with a waste gate valve.

Conventional waste gate valves have been controlled by pneumatic actuators that use supercharging pressure as a power source, but recently, electronically controlled waste gate valves that are controlled to open and close by an electric motor have also been adopted. By making the waste gate valve electrically controlled, it can be driven even when the supercharging pressure is low, and more precise control is possible.

Japanese Patent Laid-Open No. 2005-163684

By the way, when the engine is in a low speed range, the amount of exhaust gas is small, so that there are many cases where sufficient exhaust gas cannot be secured to operate the mechanical supercharger. For this reason, in an operating state in which the accelerator is depressed and accelerated from a low engine speed range, it is not possible to secure the intake supercharging pressure necessary for acceleration at an early stage.

Here, in order to increase the amount of exhaust gas supplied to the mechanical supercharger, a method of closing the waste gate valve can be considered. However, since the total amount of exhaust gas discharged from the combustion chamber is small in the low engine speed range, the turbine rotational speed of the mechanical supercharger does not increase even if the waste gate valve is closed. For this reason, there is a demand for ensuring an appropriate intake supercharging pressure at an early stage when an acceleration request is made from a low engine speed range.

Therefore, an object of the present invention is to ensure an appropriate intake supercharging pressure at an early stage and quickly increase torque when acceleration is requested from a low engine speed range.

In order to solve the above problems, the present invention provides an exhaust turbine disposed in an exhaust passage and a supercharger that supercharges intake air to a combustion chamber disposed in an intake passage, and is driven by the exhaust turbine. A mechanical supercharger, a supercharger for supercharging intake air to a combustion chamber disposed in the intake passage, the electrically driven electric supercharger, and the exhaust passage in the exhaust passage A control device for controlling an engine comprising an exhaust bypass passage connecting an upstream side and a downstream side of an exhaust turbine and an exhaust bypass valve for opening and closing the exhaust bypass passage, wherein the exhaust bypass valve is in an open state Sometimes an engine control device for operating the electric supercharger was adopted.

The engine further includes an intake bypass passage that connects an upstream side and a downstream side of the electric supercharger in the intake passage, and an intake bypass valve that opens and closes the intake bypass passage. Further includes a determination unit that determines the operation of the electric supercharger, and the engine control device opens the exhaust bypass valve when the operation of the electric supercharger is determined. A configuration in which the electric supercharger is operated after the intake bypass valve is closed later can be employed.

The engine control device stops the electric supercharger after closing the exhaust bypass valve when the operation of the electric supercharger is shifted to the operation of the mechanical supercharger. A configuration can be employed.

Furthermore, when the engine control device shifts from the operation of the electric supercharger to the operation of the mechanical supercharger, the engine bypass device opens the intake bypass valve after closing the exhaust bypass valve. Therefore, it is possible to employ a configuration in which the electric supercharger is stopped.

Here, the determination unit determines whether the electric supercharger in the intake passage is equal to or higher than a predetermined pressure, or when the electric energy used by the electric supercharger is equal to or higher than a predetermined electric energy. The electric supercharger is not actuated when the usage time of the charger exceeds a predetermined time or when the calorific value of the electric supercharger exceeds a predetermined calorific value It is possible to adopt a configuration that determines that

The opening degree of the exhaust bypass valve at the time of transition from the open state to the closed state may be determined based on the supercharging output from the electric supercharger.

According to the present invention, since the electric supercharger is driven when the exhaust bypass valve is in the open state, an appropriate intake air supercharging pressure required for the acceleration request is ensured, and the torque is quickly applied. Can be increased.

It is a schematic diagram of the control apparatus of the engine which shows embodiment of this invention. It is a graph which shows the time of starting of the engine which concerns on this embodiment. It is a graph which shows the time of starting of the engine which concerns on this embodiment. It is a flowchart which shows control of the engine which concerns on this embodiment.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram conceptually showing an overall control system E composed of an engine and its control device according to this embodiment.

The engine 1 of this embodiment is a four-cycle internal combustion engine, and is an automobile gasoline engine. As shown in FIG. 1, the configuration of the engine 1 includes an intake port 3 for sending intake air into a cylinder 2 having a combustion chamber therein, an intake passage 4 leading to the intake port 3, and an exhaust passage 14 drawn from the exhaust port 13. And a fuel injection device for injecting fuel into the intake port 3 or the combustion chamber. The intake port 3 and the exhaust port 13 are opened and closed by valves.

In this embodiment, a four-cylinder engine having four cylinders is assumed, but the present invention can be applied regardless of the number of cylinders.

In the intake passage 4 leading to the combustion chamber, a throttle valve 5 that adjusts a flow area to the intake port 3 toward the upstream side from the intake port 3 that is a connection portion to the combustion chamber, intake air flowing through the intake passage 4 An intake air cooling device (intercooler) 6 for cooling, a mechanical compressor 11 of a mechanical supercharger (turbocharger) 10, and a second throttle valve 7 for adjusting the flow area in the intake passage 4 on the upstream side, An air cleaner (not shown) or the like is provided.

In the exhaust passage 14, the turbine 12 of the mechanical supercharger 10, a catalyst for removing unburned hydrocarbons (HC) and the like in the exhaust, etc. from the exhaust port 13, which is a connection portion to the combustion chamber, toward the downstream side. Are provided with an exhaust purification unit 15, a silencer 16, and the like.

As shown in FIG. 1, the mechanical supercharger 10 includes a mechanical compressor 11 that is disposed in the intake passage 4 and supercharges intake air introduced into the combustion chamber. An exhaust turbine 12 for rotating the mechanical compressor 11 is disposed in the exhaust passage 14. The mechanical compressor 11 and the exhaust turbine 12 are connected coaxially. When the exhaust turbine 12 rotates by exhaust gas flowing through the exhaust passage 14, the rotation is transmitted to the mechanical compressor 11 in the intake passage 4. The intake air flowing through the intake passage 4 is supercharged by the rotation of the mechanical compressor 11. That is, the mechanical compressor 11 is driven by the exhaust turbine 12.

Further, an exhaust bypass device 40 including an exhaust bypass passage 41 that connects the upstream side and the downstream side of the exhaust turbine 12 in the exhaust passage 14, and an exhaust bypass valve 42 that opens and closes the exhaust bypass passage 41, a so-called waste gate valve. A device is provided. If the exhaust bypass valve 42 is opened, a part of the exhaust gas flowing to the exhaust turbine 12 side is diverted to the exhaust bypass passage 41 side, and the exhaust energy applied to the exhaust turbine 12 is reduced.

In this embodiment, the exhaust bypass valve 42 is an electrically controlled wastegate valve that is controlled to open and close by an electric motor.

Furthermore, an electric supercharger 30 is arranged in the middle of the intake passage 4. The electric supercharger 30 includes an electric compressor 32 that is disposed in the intake passage 4 and supercharges intake air into the combustion chamber. When the electric compressor 32 is driven by supplying electric power, the intake air flowing in the intake passage 4 is supercharged.

The intake passage 4 is provided with an intake bypass passage 33 that connects the upstream side and the downstream side of the electric compressor 32 and an intake bypass valve 34 that opens and closes the intake bypass passage 33. When driving the electric compressor 32, the intake bypass valve 34 needs to be closed.

The driving power for the exhaust bypass valve 42, the electric compressor 32, and the intake bypass valve 34 is supplied from a battery 60. Here, the battery 60 that supplies power to the exhaust bypass valve 42, the electric compressor 32, and the intake bypass valve 34 is used in common with the battery that supplies power to other parts of the engine 1 and the vehicle in which the engine 1 is mounted. Yes. However, the battery that supplies driving power to the exhaust bypass valve 42 and the electric compressor 32 can be provided separately from the battery that supplies power to the engine 1 and the entire vehicle.

A downstream side of the exhaust turbine 12 in the exhaust passage 14 and a midway portion between the mechanical compressor 11 and the second throttle valve 7 in the intake passage 11 are communicated by an exhaust gas recirculation passage 21 constituting the exhaust gas recirculation device 20. . A part of the exhaust gas discharged from the combustion chamber returns to the upstream side of the mechanical compressor 11 and the electric compressor 32 in the intake passage 4 as the recirculation gas via the exhaust recirculation passage 21. An exhaust gas recirculation valve 22 is provided in the exhaust gas recirculation passage 21. The recirculated gas merges with the intake air in the intake passage 4 in accordance with the pressure state in the intake passage 4 that accompanies the opening and closing of the exhaust gas recirculation valve 22 and the opening and closing of the second throttle valve 7.

The vehicle on which the engine 1 is mounted includes an electronic control unit ECU (ECU: Electronic Control Unit) 50 as a control device that controls the engine 1.

The ECU 50 performs fuel injection by a fuel injection device (not shown) provided in the intake port 3 or the combustion chamber, control of supercharging pressure, control of the opening degree of the throttle valve 5 and the second throttle valve 7, exhaust gas recirculation. Commands necessary for control of the apparatus 20 and other control of the engine are performed.

The ECU 50 also includes a mechanical supercharger control means 51 that controls the mechanical supercharger 10, an electric supercharger control means 52 that controls the electric supercharger 30, and an intake bypass that controls the intake bypass valve 34. The apparatus control means 53 and the exhaust bypass apparatus control means 54 which controls the exhaust bypass valve 42 of the exhaust bypass apparatus 40 are provided. Further, the ECU 50 includes a determination unit 55 that determines the operation of the electric supercharger 30. Specifically, the ECU 50 stores an operation region map of the electric supercharger 30 defined based on the amount of air introduced into the combustion chamber and the supercharging pressure of the intake air of the engine 1 ( The determination unit 55 determines whether the electric supercharger 30 is operating or not by determining whether or not the target intake air amount and the target supercharging pressure belong to the operating region.

As shown in FIG. 1, the intake passage 4 is provided with a purge device a that temporarily stores the evaporated fuel generated in the fuel tank in a canister or the like and introduces it into the downstream side of the throttle valve 5. . Further, a blow-by gas recirculation device b that recirculates the blow-by gas mainly containing unburned gas leaked into the engine 1 to the intake port 3, opens to the upstream side of the second throttle valve 7, and the pressure in the crankcase A breather device e and the like are provided. These devices are also controlled by the ECU 50.

Further, in the intake passage 4, as a sensor device for acquiring information necessary for controlling the engine 1, a pressure sensor c on the downstream side of the throttle valve 5, a pressure sensor d on the upstream side of the throttle valve 5, and the inside of the intake passage 4 are provided. An air flow sensor f for detecting the amount of flowing air is provided.

The exhaust passage 14 is provided with an exhaust temperature sensor g for detecting the temperature of the exhaust gas as a sensor device that acquires information necessary for controlling the engine 1.

Further, the engine 1 is provided with a water temperature sensor i for detecting the temperature of the cooling water for cooling the cylinder block and the like, and a rotation speed sensor j for detecting the rotation speed of the crankshaft of the engine 1. A vehicle body (not shown) of the vehicle is provided with an accelerator opening sensor k that detects the amount of depression of the accelerator.

Information on these various sensors can be acquired by the ECU 50 through a cable.

Hereinafter, the control during acceleration of the engine 1 will be described based on the flowchart of FIG. This flow is stored in a storage device provided in the ECU 50, and is executed as necessary.

First, it is assumed that there is an acceleration request in step S1. That is, it is assumed that the driver has depressed the accelerator pedal more than a predetermined depression amount by the accelerator operation.

In step S2, a target intake air amount required for the engine 1 is calculated from the torque to be output by the current engine 1 according to the acceleration request detected in S1. A target boost pressure is set from the target intake air amount based on a map or the like stored in the ECU 50.

Here, the accelerator opening detected by the accelerator opening sensor k, the coolant temperature detected by the water temperature sensor i, the rotational speed of the engine 1, the torque of the engine 1, etc. are necessary for the control of the engine 1. Information is read into the ECU 50.

Next, in step S3, the determination unit 55 of the ECU 50 determines whether or not the target intake air amount calculated in step S2 belongs to the operating region of the electric supercharger 30. Here, in the ECU 50, for example, as shown in FIG. 2 described later, respective operation regions determined according to the characteristics of the electric supercharger 30 and the mechanical supercharger 10 are stored as a map. That is, a map is set in which a region is set so that supercharging by the electric supercharger 30 is performed at a low intake amount and supercharging is performed by the mechanical supercharger 10 at a high intake amount. Whether or not the operating state of the engine 1 belongs to the operating region of the electric supercharger 30 is determined by comparing the target intake air amount and the target supercharging pressure obtained in step S2 with reference to this map. Further, whether or not it is the operating region of the electric supercharger 30 depends on the amount of charge of the battery 60 that supplies power to the electric supercharger 30 and the durability of the motor that drives the electric compressor 32. You may judge.

If it is determined in step S3 that the electric turbocharger is operating, the intake bypass valve 34 is controlled to be closed in step S4 to close the intake bypass passage 33, and then the exhaust bypass valve is determined in step S5. (Wastegate valve) 42 is controlled to be in an open state. Thereafter, the supercharger is started by operating the electric supercharger 30 and driving the electric compressor 32 in step S6.

Thus, when the electric supercharger 30 is operated, the exhaust bypass valve 42 is controlled to be in an open state, so that a part of the exhaust gas flowing to the exhaust turbine 12 side is diverted to the exhaust bypass passage 41 side. Then, the exhaust energy applied to the exhaust turbine 12 is reduced, so that an increase in pressure in the exhaust port 13 is suppressed.

On the other hand, when the electric supercharger 30 is operated, the pressure on the intake side increases due to supercharging of the electric compressor 32. Thus, when the pressure on the intake side becomes higher than the pressure on the exhaust side, the exhaust can be prevented from flowing back into the cylinder. That is, the scavenging effect in the cylinder is enhanced and the in-cylinder residual combustion gas amount is reduced. When the in-cylinder residual gas amount decreases, the in-cylinder gas temperature decreases and knocking is suppressed, so that the ignition timing can be advanced. If the ignition timing is advanced, the thermal efficiency increases and the engine output increases, so that the acceleration performance can be improved.

Further, after the intake bypass valve 34 is controlled to be closed, the exhaust bypass valve 42 is controlled to be opened before the electric supercharger 30 operates (the electric compressor 32 is driven), so that the electric supercharger 30 The scavenging effect can be easily obtained by lowering the exhaust pressure in advance before the supercharging due to is supplied to the air. In the control of the engine 1, the valve over in which both the intake valve that opens and closes the opening of the intake passage 4 to the combustion chamber and the exhaust valve that opens and closes the opening of the exhaust passage 14 to the combustion chamber are opened. Since the lap period is set, a scavenging effect can be expected.

Next, the case where the target intake air amount calculated in step 2 does not belong to the operation region by the electric supercharger 30 will be described.

In step S3, when it is determined that the intake air amount calculated in step S2 does not belong to the operating region of the electric supercharger 30, the exhaust bypass valve 42 is controlled to be closed in step S9. At this time, exhaust gas is supplied to the exhaust turbine 12 of the mechanical supercharger 10, and the mechanical compressor 11 arranged coaxially with the exhaust turbine 12 starts supercharging. Thereafter, the intake bypass valve 34 is controlled to be opened in step S10, and finally the operation of the electric supercharger 30 is stopped in step S11, and the supercharging by the electric compressor 32 is stopped. In this way, after the exhaust bypass valve 42 is controlled to be closed, the intake bypass valve 33 is controlled to be opened before the operation of the electric supercharger 30 is stopped, whereby the electric compressor 32 and the mechanical compressor 11 are controlled. By creating a state in which supercharging by both of these occurs, it is possible to prevent the intake air amount from becoming insufficient due to the supercharging response and the torque of the engine 1 from dropping.

Thereafter, the intake air amount is detected in step S7, and it is determined in step S8 whether the intake air amount supercharged by the electric supercharger 30 or the mechanical supercharger 10 has reached the target intake air amount set in step S2. If the target intake air amount has not been reached, the process returns to step S2 and the same control is repeated up to the target intake air amount.

On the other hand, when the target intake air amount is reached, the mechanical supercharger 10 is activated and the exhaust bypass valve 42 is closed to stop the supercharging of the mechanical supercharger 10 or the electric supercharger 30. If so, the exhaust bypass valve 42 is opened in step S12 so that supercharging does not occur. If the electric compressor 32 of the electric supercharger 30 is driven, the intake bypass valve 42 is opened in step 13. In step S14, the electric supercharger 30 is stopped, and the control is terminated in step S15.

Here, as a reference for determining whether or not the operating state of the engine 1 is out of the operating range of the electric supercharger 30, the following determination criteria can be adopted.

For example, considering the durability and driving force of the motor that drives the electric compressor 32, the supercharging pressure in the intake passage 4 is set as the pressure required for the electric supercharger 30 in response to the acceleration request. In addition to the case where the electric pressure used by the electric compressor 32 becomes equal to or higher than a predetermined electric energy, or when the electric compressor 32 has been used for a predetermined time. When it becomes more than the time or when the heat generation amount of the electric compressor 32 exceeds a predetermined heat generation amount determined in advance, the determination unit 55 determines that the operation state of the engine 1 is that of the electric supercharger 30. The electric supercharger 30 is determined not to be operated because it is determined that it is out of the operating range.

Since the electric compressor 32 uses a large amount of electric power, a predetermined electric energy that is a use limit is set in consideration of the capacity of the battery 60. Alternatively, a predetermined time that is the upper limit may be set for the usage time of the electric compressor 32, or a predetermined heat generation amount that is the upper limit may be set for the heat generation amount of the electric compressor 32. That is, when these electric energy, usage time, and calorific value exceed the corresponding predetermined values, further operation of the electric compressor 32 is not preferable. In this embodiment, the electric supercharging is performed. The machine 30 is not operated.

In step S9, the opening degree of the exhaust bypass valve 42 when shifting from the open state to the closed state may be determined based on the supercharging output from the electric compressor 32. That is, in step S11, as the supercharging output by the electric compressor 32 gradually decreases, the exhaust bypass valve 42 is gradually closed and the opening thereof gradually decreases. Here, in correspondence with the supercharging output by the electric compressor 32, the opening degree of the exhaust bypass valve 42 is determined each time using a map or the like.

FIG. 2 shows the relationship between the amount of air introduced into the combustion chamber and the supercharging pressure of the intake air of the engine 1 when acceleration is requested from the low rotation range of the engine 1. A symbol A shown in the graph of FIG. 2 indicates an operation region in which the electric supercharger 30 can cope with supercharging, and a symbol B indicates an operation region in which the mechanical supercharger 10 can cope with supercharging. .

In the above control, when the acceleration request from the low rotation range is requested, when the supercharging by the electric supercharger 30 is finished and the supercharging by the mechanical supercharger 10 is shifted, the exhaust bypass valve 42 is closed, The driving of the compressor 32 is stopped. The timing of closing the exhaust bypass valve 42 and stopping the driving of the electric compressor 32 corresponds to the position of the symbol p2 in the graph of FIG. That is, when the reference sign p2, which is the end of the overlapping portion t1 between the operation region of the electric supercharger 30 and the operation region of the mechanical supercharger 10, starts closing the exhaust bypass valve 42, the electric compressor 32 It is time to start decreasing the drive output. The time from the start of closing the exhaust bypass valve 42 to the complete closure, the time from the start of the decrease in the output of the drive of the electric compressor 32 to the complete stop of the drive, It is determined appropriately according to the driving situation such as the size.

It should be noted that the timing of starting closing of the exhaust bypass valve 42 and the timing of starting to decrease the output of the drive of the electric compressor 32 are the operating region of the electric supercharger 30 and the operating region of the mechanical supercharger 10. It is good also as the timing of the code | symbol p1 which is the beginning of the overlapping part t1. Or it is good also as any timing between the position shown to the code | symbol p1, and the position shown to the code | symbol p2.

FIG. 3 shows the relationship between the elapsed time from the start time of the acceleration request and the supercharging pressure in the intake passage 4 when the acceleration is requested from the low rotation range of the engine 1. A symbol A ′ shown in the graph of FIG. 3 indicates a change in the supercharging pressure by the electric supercharger 30, and a symbol B ′ indicates a change in the supercharging pressure by the mechanical supercharger 10.

When the supercharging by the electric supercharger 30 is finished and the process proceeds to supercharging by the mechanical supercharger 10, in FIG. 3, the exhaust bypass valve 42 starts to be closed at the timing indicated by the symbol q2. The output of the drive of the compressor 32 is decreasing. In this embodiment, the timing of their start corresponds to the position of the symbol p2 in the graph of FIG. The time from the start of closing the exhaust bypass valve 42 to the complete closure, the time from the start of the decrease in the output of the drive of the electric compressor 32 to the complete stop of the drive, In FIG. 3, the exhaust bypass valve 42 is completely closed and the driving of the electric compressor 32 is completely stopped at timing q3.

In this embodiment, the exhaust bypass device 40, that is, the waste gate valve device is electrically controlled, so that it can be driven even when the supercharging pressure is low, and more precise control is possible. It may be controlled by a pneumatic actuator using a supercharging pressure as a power source. At this time, it is desirable to use a negative pressure type using a vacuum pump.

Although the engine 1 of this embodiment is a four-cycle gasoline engine for automobiles, it is not limited to this embodiment, and the present invention can be applied to a diesel engine as well as other types of gasoline engines.

1 Engine 2 Cylinder 3 Intake port 4 Intake passage 5 Throttle valve 6 Intake cooling device (intercooler)
7 Second throttle valve 10 Mechanical supercharger 11 Mechanical compressor 12 Exhaust turbine 13 Exhaust port 14 Exhaust passage 15 Exhaust purifier 16 Silencer 20 Exhaust recirculation device 21 Exhaust recirculation passage 22 Exhaust recirculation valve 30 Electric supercharger 32 Electric compressor 33 Intake bypass passage 34 Intake bypass valve 40 Exhaust bypass device 41 Exhaust bypass passage 42 Exhaust bypass valve 50 ECU
51 Mechanical Supercharger Control Unit 52 Electric Supercharger Control Unit 53 Intake Bypass Device Control Unit 54 Exhaust Bypass Device Control Unit 55 Determination Unit

Claims

An exhaust turbine disposed in the exhaust passage, and a supercharger that supercharges intake air to the combustion chamber disposed in the intake passage, the mechanical supercharger driven by the exhaust turbine, and the intake passage A supercharger that supercharges intake air into the disposed combustion chamber, the electrically driven supercharger;
An exhaust bypass passage connecting the upstream side and the downstream side of the exhaust turbine in the exhaust passage, an exhaust bypass valve opening and closing the exhaust bypass passage,
A control device for controlling an engine comprising:
An engine control device for operating the electric supercharger when the exhaust bypass valve is in an open state.
The engine further includes an intake bypass passage that connects an upstream side and a downstream side of the electric supercharger in the intake passage, and an intake bypass valve that opens and closes the intake bypass passage,
The engine control device comprises:
A determination unit for determining the operation of the electric supercharger;
The engine control device comprises:
When the operation of the electric supercharger is determined,
The engine control device according to claim 1, wherein the electric supercharger is operated after the intake bypass valve is closed after the exhaust bypass valve is opened.
The engine control device comprises:
The engine control according to claim 2, wherein when the operation of the electric supercharger is shifted to the operation of the mechanical supercharger, the electric supercharger is stopped after the exhaust bypass valve is closed. apparatus.
The engine control device comprises:
When moving from the operation of the electric supercharger to the operation of the mechanical supercharger, after closing the exhaust bypass valve, opening the intake bypass valve and then stopping the electric supercharger The engine control device according to claim 2 or 3 to be caused.
The determination unit
When the supercharging pressure in the intake passage is equal to or higher than a predetermined pressure, when the electric energy used by the electric supercharger is equal to or higher than the predetermined electric energy, the usage time of the electric supercharger is a predetermined time It is determined that the electric supercharger is not operated when either of the above cases occurs or when the calorific value of the electric supercharger exceeds a predetermined calorific value. The engine control device according to any one of the above.
The engine control device according to claim 4, wherein an opening degree of the exhaust bypass valve at the time of transition from an open state to a closed state is determined based on a supercharge output by the electric supercharger.