Control device for an internal combustion engine, and control program for an internal combustion engine.

Abstract

This improves the responsiveness of the actual boost pressure when the opening of the wastegate valve is changed. [Solution] The internal combustion engine comprises a cylinder, an intake passage, an exhaust passage, a turbocharger, and an actuator. The turbocharger includes a turbine wheel, a compressor wheel, a bypass passage, and a wastegate valve. The wastegate valve opens and closes the flow path of the bypass passage. The control device of the internal combustion engine acquires the actual boost pressure as the measured value of the boost pressure, which is the pressure in the portion downstream of the compressor wheel in the intake passage (S13). When the control device of the internal combustion engine changes the opening of the wastegate valve, it increases the amount of change in power supplied to the actuator when the amount of change in the actual boost pressure over a predetermined period is a first value, compared to when the amount of change in the actual boost pressure over a predetermined period is a second value which is greater than the first value (S51, S52).

Description

Technical Field

[0001] The present invention relates to a control device for an internal combustion engine and a control program for an internal combustion engine.

Background Art

[0002] The vehicle of Patent Document 1 includes an internal combustion engine. The internal combustion engine includes a cylinder, an intake passage, an exhaust passage, a turbocharger, and an actuator. The cylinder is a space for burning fuel. The intake passage introduces intake air from outside the internal combustion engine into the cylinder. The exhaust passage discharges exhaust from the cylinder to the outside of the internal combustion engine. The turbocharger includes a turbine wheel, a compressor wheel, a bypass passage, and a wastegate valve. The turbine wheel is located in the middle of the exhaust passage. The turbine wheel rotates according to the flow of exhaust in the exhaust passage. The compressor wheel is located in the middle of the intake passage. The compressor wheel rotates integrally with the turbine wheel. The first end of the bypass passage is connected to a portion upstream of the turbine wheel in the exhaust passage. The second end of the bypass passage is connected to a portion downstream of the turbine wheel in the exhaust passage. The wastegate valve opens and closes the flow path of the bypass passage. The actuator operates the wastegate valve according to the current applied to the actuator.

[0003] The vehicle described in Patent Document 1 is equipped with a control device. The control device controls an internal combustion engine. Specifically, the control device acquires the actual boost pressure as the measured value of the boost pressure in the intake passage downstream of the compressor wheel. The control device also acquires the target boost pressure as the target value of the boost pressure. The control device then applies a first current value to the actuator when the wastegate valve is maintained in a fully closed position, the actual boost pressure is lower than the target boost pressure, and the absolute value of the difference between the actual boost pressure and the target boost pressure is greater than or equal to a threshold. On the other hand, the control device applies a second current value smaller than the first current value to the actuator when the wastegate valve is maintained in a fully closed position, the actual boost pressure is lower than the target boost pressure, and the absolute value of the difference between the actual boost pressure and the target boost pressure is less than a threshold. As a result, the responsiveness of the actual boost pressure when the wastegate valve opens from a fully closed position to an open position can be improved in the internal combustion engine described in Patent Document 1. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2018-189051 [Overview of the project] [Problems that the invention aims to solve]

[0005] In internal combustion engines like the one described in Patent Document 1, it is sometimes desirable to improve the responsiveness of the actual boost pressure not only when the wastegate valve is maintained in a fully closed position, but also when the wastegate valve opening changes. [Means for solving the problem]

[0006] To solve the above problems, a control device for an internal combustion engine controls an internal combustion engine comprising: a cylinder for burning fuel; an intake passage for introducing intake air into the cylinder; an exhaust passage for discharging exhaust from the cylinder; a turbine wheel located in the exhaust passage and rotating according to the exhaust flow in the exhaust passage; a compressor wheel located in the intake passage and rotating integrally with the turbine wheel; a bypass passage connecting the upstream and downstream portions of the exhaust passage with respect to the turbine wheel; and a turbocharger including a wastegate valve that opens and closes the flow path of the bypass passage; and an actuator that operates the wastegate valve according to supplied power. The control device takes an internal combustion engine as the target of control and performs the following actions: obtain the actual boost pressure as a measured value of the boost pressure, which is the pressure in the downstream portion of the intake passage with respect to the compressor wheel; and, when changing the opening of the wastegate valve, increase the amount of change in power compared to a second value, where the amount of change in the actual boost pressure during a predetermined period is greater than the first value, when the amount of change in the actual boost pressure during a predetermined period is a first value.

[0007] A control program for an internal combustion engine to solve the above problems is applied to a control device that controls an internal combustion engine comprising: a cylinder for burning fuel; an intake passage for introducing intake air into the cylinder; an exhaust passage for discharging exhaust from the cylinder; a turbine wheel located in the exhaust passage and rotating according to the exhaust flow in the exhaust passage; a compressor wheel located in the intake passage and rotating integrally with the turbine wheel; a bypass passage connecting the upstream and downstream portions of the exhaust passage with respect to the turbine wheel; and a turbocharger including a wastegate valve that opens and closes the flow path of the bypass passage; and an actuator that operates the wastegate valve according to supplied power. The control device is instructed to obtain the actual boost pressure as a measured value of the boost pressure, which is the pressure in the downstream portion of the intake passage with respect to the compressor wheel; and, when changing the opening of the wastegate valve, to increase the amount of change in power compared to a second value, where the amount of change in the actual boost pressure during a predetermined period is greater than the first value, when the amount of change in the actual boost pressure during a predetermined period is a first value. [Effects of the Invention]

[0008] According to the above configuration, for example, it is possible to improve the responsiveness of the actual boost pressure when changing the opening of the wastegate valve while suppressing excessive changes in the actual boost pressure compared to the case where the amount of change in power is always large. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a schematic diagram of the vehicle's configuration. [Figure 2] Figure 2 is a flowchart showing the opening degree control. [Modes for carrying out the invention]

[0010] <Outline of the vehicle configuration> One embodiment of the present invention will be described below with reference to Figures 1 and 2. First, the general configuration of the vehicle 100 will be described. In the following description, when simply referred to as upstream and downstream, they refer to the upstream and downstream of the intake and exhaust flows.

[0011] As shown in Figure 1, the vehicle 100 is equipped with an internal combustion engine 10. The internal combustion engine 10 comprises an intake pipe 11, multiple cylinders 12, and an exhaust pipe 13. The internal combustion engine 10 also comprises multiple pistons 21, multiple connecting rods 22, and a crankshaft 23.

[0012] Cylinder 12 is the space for burning the fuel-air mixture. Note that Figure 1 shows only one cylinder 12 as a representative example. The piston 21 is located inside cylinder 12. The piston 21 reciprocates inside cylinder 12 due to the combustion of the fuel-air mixture. The piston 21 is connected to the crankshaft 23 via a connecting rod 22. The crankshaft 23 rotates inside cylinder 12 due to the reciprocating motion of the piston 21.

[0013] The intake manifold 11 is connected to each cylinder 12. The intake manifold 11 introduces intake air into the cylinder 12 from outside the internal combustion engine 10. The exhaust manifold 13 is connected to each cylinder 12. The exhaust manifold 13 discharges exhaust from the cylinder 12 to the outside of the internal combustion engine 10.

[0014] As shown in Figure 1, the internal combustion engine 10 includes a turbocharger 40, a linkage mechanism 50, and an actuator 60. The turbocharger 40 includes a compressor housing 41, a bearing housing 42, a turbine housing 43, and a wastegate valve 45. The turbocharger 40 also includes a compressor wheel 46, a connecting shaft 47, and a turbine wheel 48.

[0015] The compressor housing 41 is located in the middle of the intake pipe 11. The compressor housing 41 partitions the internal space through which the intake air flows. The compressor wheel 46 is located in the aforementioned internal space within the compressor wheel 46. In this embodiment, the aforementioned internal space within the compressor wheel 46 and the internal space within the intake pipe 11 constitute the intake passage 11Z.

[0016] The turbine housing 43 is located in the middle of the exhaust pipe 13. The turbine housing 43 partitions the internal space through which the exhaust gas flows. The turbine wheel 48 is located in the aforementioned internal space within the turbine housing 43. In this embodiment, the aforementioned internal space within the turbine wheel 48 and the internal space within the exhaust pipe 13 constitute the exhaust passage 13Z.

[0017] The bearing housing 42 connects the compressor housing 41 and the turbine housing 43. The bearing housing 42 houses the connecting shaft 47 in a rotatable state. The first end of the connecting shaft 47 is connected to the turbine wheel 48. The second end of the connecting shaft 47 is connected to the compressor wheel 46.

[0018] In the turbocharger 40, the turbine wheel 48 rotates in accordance with the exhaust flow in the exhaust passage 13Z. As a result, the connecting shaft 47 and the compressor wheel 46 rotate together with the turbine wheel 48. Consequently, the compressor wheel 46 compresses the intake air flowing through the intake passage 11Z and supplies it downstream to the compressor wheel 46.

[0019] The turbine housing 43 is provided with a bypass passage 43A. The first end of the bypass passage 43A is connected to the upstream portion of the exhaust passage 13Z relative to the turbine wheel 48. The second end of the bypass passage 43A is connected to the downstream portion of the exhaust passage 13Z relative to the turbine wheel 48.

[0020] The waist gate valve 45 is located near the bypass passage 43A. The waist gate valve 45 opens and closes the flow path of the bypass passage 43A. In the present embodiment, the waist gate valve 45 opens and closes the downstream end of the bypass passage 43A. The waist gate valve 45 is connected to the actuator 60 via the link mechanism 50. The actuator 60 operates the waist gate valve 45 according to the electric power supplied to the actuator 60. Specifically, the actuator 60 changes the opening degree of the waist gate valve 45 according to the current supplied to the actuator 60. In the present embodiment, as the current supplied to the actuator 60 increases, the power for controlling the waist gate valve 45 to the closed side by the actuator 60 increases.

[0021] As shown in FIG. 1, the internal combustion engine 10 includes an air cleaner 31, an intercooler 32, a throttle valve 33, and a plurality of fuel injection valves 34. The air cleaner 31 is located upstream of the compressor wheel 46 in the intake passage 11Z. The air cleaner 31 removes foreign substances contained in the intake air flowing through the intake passage 11Z.

[0022] The intercooler 32 is located downstream of the compressor wheel 46 in the intake passage 11Z. The intercooler 32 cools the intake air flowing through the intake passage 11Z. The throttle valve 33 is located downstream of the intercooler 32 in the intake passage 11Z. The throttle valve 33 adjusts the amount of intake air flowing through the intake passage 11Z.

[0023] The fuel injection valve 34 is located downstream of the throttle valve 33 in the intake passage 11Z. The fuel injection valve 34 supplies fuel to the cylinder 12 through the intake passage 11Z by injecting fuel supplied from a fuel tank not shown into the intake passage 11Z.

[0024] As shown in Figure 1, the vehicle 100 is equipped with an airflow meter 81, a boost pressure sensor 82, a crank angle sensor 83, an accelerator pedal operation sensor 84, and a vehicle speed sensor 85. The airflow meter 81 is attached to the air cleaner 31. The airflow meter 81 detects the intake airflow rate GA, which is the amount of intake air flowing through the intake passage 11Z per unit time.

[0025] The boost pressure sensor 82 is mounted in the intake passage 11Z on the downstream side of the throttle valve 33. The boost pressure sensor 82 detects the actual boost pressure PM as the measured value of the boost pressure P, which is the pressure in the intake passage 11Z on the downstream side of the throttle valve 33. In other words, the boost pressure P is the pressure in the intake passage 11Z on the downstream side of the compressor wheel 46.

[0026] The crank angle sensor 83 detects the crank angle SC, which is the angular position of the crankshaft 23. The accelerator pedal operation amount sensor 84 detects the accelerator pedal operation amount ACC, which is the amount of accelerator pedal operation performed by the driver of the vehicle 100. The vehicle speed sensor 85 detects the vehicle speed SP, which is the speed of the vehicle 100.

[0027] As shown in Figure 1, the vehicle 100 is equipped with a control device 90. The control device 90 acquires various information from an airflow meter 81, a boost pressure sensor 82, a crank angle sensor 83, an accelerator pedal operation amount sensor 84, and a vehicle speed sensor 85.

[0028] The control device 90 comprises an execution device 91 and a storage device 92. An example of the execution device 91 is a CPU. The storage device 92 includes a read-only ROM, a read and write volatile RAM, and a read and write non-volatile storage. The storage device 92 pre-stores various programs and various data. Specifically, the storage device 92 pre-stores a control program 92A as one of the various programs. The execution device 91 executes various processes described later by executing the control program 92A stored in the storage device 92.

[0029] The execution device 91 of the control device 90 calculates the required vehicle driving force, which is the required driving force necessary for the vehicle 100 to run, based on the accelerator operation amount ACC and the vehicle speed SP. The execution device 91 controls the internal combustion engine 10 based on the required vehicle driving force. Specifically, the execution device 91 controls the opening degree of the throttle valve 33, the amount of fuel injected from the fuel injector 34, the opening degree of the wastegate valve 45, etc., by outputting control signals to the internal combustion engine 10.

[0030] <Opening degree control> Next, with reference to Figure 2, the opening degree control performed by the control device 90 will be described. This opening degree control is a control of the opening degree of the wastegate valve 45. In this embodiment, the execution device 91 of the control device 90 starts the opening degree control at predetermined control cycles A, provided that the internal combustion engine 10 is operating. An example of a control cycle A is several milliseconds to tens of milliseconds.

[0031] As shown in Figure 2, when the execution device 91 of the control device 90 starts opening control, it executes the process in step S11. In step S11, the execution device 91 calculates the engine rotation speed NE, which is the rotational speed of the crankshaft 23. Specifically, the execution device 91 calculates the engine rotation speed NE based on the crank angle SC. After step S11, the execution device 91 proceeds to step S12.

[0032] In step S12, the execution device 91 obtains the intake air flow rate GA at the start of the current opening control. After step S12, the execution device 91 proceeds to step S13.

[0033] In step S13, the execution device 91 obtains the actual boost pressure PM at the start of the current opening control. After step S13, the execution device 91 proceeds to step S14.

[0034] In step S14, the execution device 91 calculates the fuel injection amount F, which is the amount of fuel to be injected from the fuel injector 34. In this embodiment, the execution device 91 calculates the fuel injection amount F based on the engine rotation speed NE and the required vehicle driving force, etc. For example, the execution device 91 calculates the fuel injection amount F by associating the engine rotation speed NE and the required vehicle driving force, etc., with a predetermined control map. After step S14, the execution device 91 proceeds to step S15.

[0035] In step S15, the execution device 91 calculates the target boost pressure PT, which is the target value of the boost pressure P. In this embodiment, the execution device 91 calculates the target boost pressure PT based on the engine rotation speed NE and the fuel injection amount F. For example, the execution device 91 calculates the target boost pressure PT by associating the engine rotation speed NE and the fuel injection amount F with a predetermined control map. After step S15, the execution device 91 proceeds to step S16.

[0036] In step S16, the execution device 91 calculates the base target opening ODB, which is a reference value for the target opening of the wastegate valve 45. In this embodiment, the execution device 91 calculates the base target opening ODB based on the engine rotational speed NE, intake air flow rate GA, and target boost pressure PT. For example, the execution device 91 calculates the base target opening ODB by associating the engine rotational speed NE, intake air flow rate GA, and target boost pressure PT with a predetermined control map. After step S16, the execution device 91 proceeds to step S21.

[0037] In step S21, the execution device 91 determines whether predetermined specific conditions are met. Here, the specific conditions are conditions for determining whether or not it is time to change the opening degree of the wastegate valve 45. In this embodiment, the execution device 91 determines that the specific conditions are met if all of the following requirements (1) and (2) are met.

[0038] Requirement (1): The actual boost pressure PM is lower than the target boost pressure PT. Requirement (2): The wastegate valve 45 must be controlled to the closed position.

[0039] For example, the execution device 91 determines requirement (2) as follows. First, the execution device 91 obtains the base target opening degree ODB calculated in step S16 of the previous opening degree control by accessing the storage device 92. Then, the execution device 91 determines that requirement (2) is met if the base target opening degree ODB calculated in step S16 of the current opening degree control is smaller than the base target opening degree ODB calculated in step S16 of the previous opening degree control. Note that the previous opening degree control is the opening degree control that occurred a control cycle A earlier than the current opening degree control.

[0040] If the execution device 91 determines in step S21 that the specific condition is not met (S21:NO), the execution device 91 proceeds to step S45. In step S45, the execution device 91 sets the base target opening degree ODB calculated in step S16 for this opening degree control as the final target opening degree ODF, which is the final value of the target opening degree of the wastegate valve 45. After step S45, the execution device 91 proceeds to step S51.

[0041] On the other hand, if the execution device 91 determines in step S21 that a specific condition has been met (S21: YES), the execution device 91 proceeds to step S31. In other words, the execution device 91 proceeds to step S31 when it determines that it is time to change the opening degree of the wastegate valve 45.

[0042] In step S31, the execution device 91 calculates the boost pressure difference PD, which is the difference between the actual boost pressure PM and the target boost pressure PT. In this embodiment, the execution device 91 calculates the boost pressure difference PD as the value obtained by subtracting the target boost pressure PT from the actual boost pressure PM. After step S31, the execution device 91 proceeds to step S32.

[0043] In step S32, the execution device 91 calculates the actual boost pressure change PMC, which is the change in actual boost pressure PM over a predetermined period. For example, the execution device 91 calculates the actual boost pressure change PMC as follows: First, the execution device 91 obtains the actual boost pressure PM from step S13 of the previous opening control by accessing the storage device 92. Then, the execution device 91 calculates the actual boost pressure change PMC as the absolute value of the difference between the actual boost pressure PM from step S13 of the current opening control and the actual boost pressure PM from step S13 of the previous opening control. Here, the previous opening control is the opening control that was a control cycle A earlier than the current opening control. Therefore, control cycle A is an example of a predetermined period. After step S32, the execution device 91 proceeds to step S33.

[0044] In step S33, the execution device 91 calculates an opening correction amount CA to correct the target opening of the wastegate valve 45. In this embodiment, the execution device 91 calculates the opening correction amount CA based on the engine rotational speed NE, intake air flow rate GA, boost pressure difference PD, and actual boost pressure change PMC. At this time, the execution device 91 calculates the opening correction amount CA as a smaller value the smaller the actual boost pressure change PMC is. Here, the opening correction amount CA is a negative value. For example, the execution device 91 calculates the opening correction amount CA by associating the engine rotational speed NE, intake air flow rate GA, boost pressure difference PD, and actual boost pressure change PMC with a predetermined control map. After step S33, the execution device 91 proceeds to step S34.

[0045] In step S34, the execution device 91 calculates the corrected target opening degree ODC, which is the base target opening degree ODB corrected by the opening degree correction amount CA. In this embodiment, the execution device 91 calculates the corrected target opening degree ODC as the base target opening degree ODB plus the opening degree correction amount CA. As described above, the opening degree correction amount CA is a negative value. Therefore, the corrected target opening degree ODC is smaller than the base target opening degree ODB. Also, as described above, the smaller the actual boost pressure change amount PMC, the smaller the opening degree correction amount CA becomes. Therefore, the smaller the actual boost pressure change amount PMC, the smaller the corrected target opening degree ODC becomes. After step S34, the execution device 91 proceeds to step S35.

[0046] In step S35, the execution device 91 sets the corrected target opening ODC as the final target opening ODF, which is the final value of the target opening of the wastegate valve 45. As described above, the corrected target opening ODC is smaller than the base target opening ODB. Therefore, the final target opening ODF in step S35 is smaller than the final target opening ODF in step S45. Also, as described above, the smaller the actual boost pressure change PMC, the smaller the corrected target opening ODC becomes. Therefore, the smaller the actual boost pressure change PMC, the smaller the final target opening ODF in step S35 becomes. After step S35, the execution device 91 proceeds to step S51.

[0047] In step S51, the execution device 91 calculates a target current I, which is the target value of the current supplied to the actuator 60, based on the final target opening degree ODF. In this embodiment, the execution device 91 calculates a larger value for the target current I as the final target opening degree ODF is smaller. For example, the execution device 91 calculates the target current I by associating the final target opening degree ODF with a predetermined control map. After step S51, the execution device 91 proceeds to step S52.

[0048] In step S52, the execution device 91 controls the current supplied to the actuator 60 according to the target current I. As described above, the smaller the actual boost pressure change PMC, the smaller the final target opening degree ODF in step S35. Therefore, if the specific conditions in step S21 are met, the smaller the actual boost pressure change PMC, the larger the target current I. In other words, when the execution device 91 changes the opening degree of the wastegate valve 45, the smaller the actual boost pressure change PMC, the larger the amount of power supplied to the actuator 60. In other words, when the execution device 91 changes the opening degree of the wastegate valve 45, the amount of power supplied to the actuator 60 is larger when the actual boost pressure change PMC is a first value compared to when the actual boost pressure change PMC is a second value which is larger than the first value. After step S52, the execution device 91 terminates the current opening degree control.

[0049] <Operation of this embodiment> As shown in Figure 2, the execution device 91 of the control device 90 starts opening degree control at predetermined control cycles A, with the condition that the internal combustion engine 10 is operating. In step S21, if the execution device 91 determines that a specific condition indicating that it is time to change the opening degree of the wastegate valve 45 has been met, it proceeds to the process from step S31 onwards. In step S32, the execution device 91 calculates the actual boost pressure change amount PMC, which is the amount of change in the actual boost pressure PM over a predetermined period. In the subsequent step S51, the execution device 91 calculates the target current I, which is the target value of the current supplied to the actuator 60. At this time, the execution device 91 increases the target current I as the actual boost pressure change amount PMC decreases. Then, in step S52, the execution device 91 controls the current supplied to the actuator 60 according to the target current I. In other words, when the execution device 91 changes the opening degree of the wastegate valve 45, it increases the amount of change in power supplied to the actuator 60 when the actual boost pressure change amount PMC is a first value compared to when the actual boost pressure change amount PMC is a second value which is greater than the first value.

[0050] <Effects of this embodiment> (1) According to this embodiment, when the actual boost pressure change amount PMC is small, in other words, when the responsiveness of the actual boost pressure PM is low, the amount of change in power supplied to the actuator 60 becomes large. Therefore, when the responsiveness of the actual boost pressure PM is low when the opening degree of the wastegate valve 45 is changed, the amount of change in the force applied from the actuator 60 to the wastegate valve 45 becomes large. As a result, the responsiveness of the actual boost pressure PM becomes higher compared to, for example, when the amount of change in the force applied from the actuator 60 to the wastegate valve 45 is small.

[0051] (2) In this embodiment, when the execution device 91 changes the opening degree of the wastegate valve 45, the smaller the actual boost pressure change PMC, the larger the amount of power supplied to the actuator 60. Therefore, the lower the responsiveness of the actual boost pressure PM, the larger the amount of power supplied to the actuator 60. This makes it possible to improve the responsiveness of the actual boost pressure PM, especially in situations where a higher responsiveness of the actual boost pressure PM is required.

[0052] (3) Generally, when the actual boost pressure PM is lower than the target boost pressure PT, there are fewer options for bringing the actual boost pressure PM closer to the target boost pressure PT compared to, for example, when the actual boost pressure PM is higher than the target boost pressure PT. In this regard, the specific condition indicating that it is time to change the opening of the wastegate valve 45 includes the requirement that the actual boost pressure PM is lower than the target boost pressure PT. Therefore, when the above specific condition is met, that is, when there are few options for bringing the actual boost pressure PM closer to the target boost pressure PT, the wastegate valve 45 can be controlled via the actuator 60 to more reliably bring the actual boost pressure PM closer to the target boost pressure PT.

[0053] (4) Generally, situations in which it is required to control the wastegate valve 45 to the closed position are situations in which it is required to increase the output of the internal combustion engine 10. Therefore, in situations in which it is required to control the wastegate valve 45 to the closed position, it is required to change the actual boost pressure PM more quickly than, for example, in cases in which it is required to control the wastegate valve 45 to the open position. In this regard, the specific conditions that indicate when it is time to change the opening of the wastegate valve 45 include the requirement that the actual boost pressure PM is lower than the target boost pressure PT, and that it is required to control the wastegate valve 45 to the closed position. Therefore, in situations in which the above specific conditions are met, that is, in situations in which it is required to change the actual boost pressure PM quickly, the responsiveness of the actual boost pressure PM can be improved.

[0054] <Example of changes> This embodiment can be implemented with the following modifications. This embodiment and the following modifications can be combined with each other to the extent that they do not contradict each other technically.

[0055] In the above embodiment, the opening degree control may be changed. For example, the specific conditions in step S21 may be changed. Specifically, the execution device 91 may determine that the specific conditions are met if one or more of requirements (1) and (2) are met. Also, specifically, the specific conditions may include other requirements in place of requirements (1) and (2). Here, examples of other requirements include the requirement that the actual boost pressure PM is higher than the target boost pressure PT, and the requirement that the wastegate valve 45 is controlled to the open side. Furthermore, specifically, the specific conditions may include other requirements in addition to requirements (1) and (2).

[0056] For example, the process in step S33 may be changed. Specifically, the execution device 91 does not need to calculate the opening correction amount CA as a smaller value when the actual boost pressure change amount PMC is small. For example, the execution device 91 may calculate the opening correction amount CA as a smaller value when the actual boost pressure change amount PMC is less than a predetermined specified change amount, compared to when the actual boost pressure change amount PMC is greater than or equal to a predetermined specified change amount. In other words, the execution device 91 may gradually reduce the opening correction amount CA based on the actual boost pressure change amount PMC. Even in this case, when the execution device 91 changes the opening of the wastegate valve 45 in step S51, the amount of change in power supplied to the actuator 60 will be larger when the actual boost pressure change amount PMC is a first value compared to when the actual boost pressure change amount PMC is a second value which is greater than the first value.

[0057] As a specific example, the execution device 91 may calculate the corrected target boost pressure PT instead of the opening degree correction amount CA. In this case, as an example, the execution device 91 can calculate the corrected target boost pressure PT based on the engine rotation speed NE, intake air flow rate GA, boost pressure difference PD, and actual boost pressure change amount PMC. Then, in step S34, the execution device 91 should calculate the corrected target opening degree ODC based on the engine rotation speed NE, intake air flow rate GA, and the corrected target boost pressure PT.

[0058] For example, the process in step S33 may be omitted. As a specific example, if the process in step S33 is omitted, in step S34, the execution device 91 may calculate the corrected target opening degree ODC based on the base target opening degree ODB and the actual boost pressure change amount PMC. In this case, the execution device 91 corrects the base target opening degree ODB to make the corrected target opening degree ODC smaller than the base target opening degree ODB. The execution device 91 should make the corrected target opening degree ODC smaller the smaller the actual boost pressure change amount PMC is.

[0059] For example, the process in step S34 may be omitted. As a specific example, if the target current I corresponding to the base target opening degree ODB becomes larger when a specific condition is met, the target current I may be calculated without calculating the corrected target opening degree ODC. In this case, as an example, the execution device 91 corrects the target current I corresponding to the base target opening degree ODB to increase the target current I when a specific condition is met. The execution device 91 should then increase the target current I as the actual boost pressure change PMC becomes smaller.

[0060] For example, the process in step S51 may be modified. Specifically, the execution device 91 does not need to calculate a larger value for the target current I as the final target opening degree ODF is smaller. As a premise, the internal combustion engine 10 employs a configuration in which the power required to control the wastegate valve 45 to the closed side by the actuator 60 increases as the current supplied to the actuator 60 decreases. In this case, in step S51, the execution device 91 may calculate a smaller value for the target current I as the final target opening degree ODF is smaller. Even with this configuration, when the execution device 91 changes the opening degree of the wastegate valve 45, if the actual boost pressure change amount PMC is a first value, the amount of change in power supplied to the actuator 60 will be larger than if the actual boost pressure change amount PMC is a second value which is larger than the first value. Also, as a specific example, in step S51, the execution device 91 may calculate a target value for the voltage supplied to the actuator 60 in place of, or in addition to, the target current I. In other words, if the power supplied to the actuator 60 can be changed, the value calculated by the execution device 91 in step S51 is not limited to the target current I.

[0061] • In the above embodiment, the configuration of the vehicle 100 may be changed. For example, the configuration of the control device 90 may be changed. Specifically, the control device 90 may be configured as a circuit including one or more processors that execute various processes according to a computer program (software). The control device 90 may also be configured as a circuit including one or more dedicated hardware circuits, such as application-specific integrated circuits (ASICs), or a combination thereof, that execute at least some of the various processes. The processor includes a CPU and memory such as RAM and ROM. The memory stores program code or instructions configured to cause the CPU to execute processes. Memory, or computer-readable media, includes any media that can be accessed by a general-purpose or dedicated computer. [Explanation of Symbols]

[0062] 10…Internal combustion engine 11…Intake pipe 11Z…Intake passage 12…Cylinder 13…Exhaust pipe 13Z…Exhaust passage 21…Piston 22…Connecting rod 23…Crankshaft 31…Air cleaner 32…Intercooler 33…Throttle valve 34…Fuel injector 40…Turbocharger 41…Compressor housing 42…Bearing housing 43…Turbine housing 43A…Bypass passage 45…Wastegate valve 46…Compressor wheel 47…Connecting shaft 48…Turbine wheel 50…Link mechanism 60…Actuator 81…Airflow meter 82…Boost pressure sensor 83…Crank angle sensor 84…Accelerator pedal input sensor 85…Vehicle speed sensor 90…Control device 91…Execution device 92…Memory device 92A…Control program 100…Vehicle

Claims

1. A cylinder that burns fuel, An intake passage for introducing intake air into the cylinder, An exhaust passage for discharging exhaust from the cylinder, A turbocharger including a turbine wheel located in the exhaust passage and rotating in accordance with the exhaust flow in the exhaust passage, a compressor wheel located in the intake passage and rotating integrally with the turbine wheel, a bypass passage connecting the upstream and downstream portions of the exhaust passage with respect to the turbine wheel, and a wastegate valve for opening and closing the flow path of the bypass passage. An actuator that operates the wastegate valve according to the supplied power, The internal combustion engine equipped with the following features is the target of control: The actual boost pressure is obtained as the measured value of the boost pressure, which is the pressure in the downstream portion of the intake passage relative to the compressor wheel. When changing the opening of the wastegate valve, the change in power is made larger than when the change in the actual boost pressure during a predetermined period is a first value, compared to when the change in the actual boost pressure during the predetermined period is a second value that is greater than the first value. Execute Control device for internal combustion engines.

2. When changing the opening degree of the wastegate valve, the smaller the change in the actual boost pressure during the specified period, the larger the change in the power. A control device for an internal combustion engine according to claim 1.

3. When changing the opening of the wastegate valve, the requirement is that the actual boost pressure is lower than the target boost pressure, which is the target value of the boost pressure. A control device for an internal combustion engine according to claim 1 or claim 2.

4. When changing the opening of the wastegate valve, the requirement is that the actual boost pressure is lower than the target boost pressure, and that the wastegate valve is controlled to the closed position. The control device for an internal combustion engine according to claim 3.

5. A cylinder that burns fuel, An intake passage for introducing intake air into the cylinder, An exhaust passage for discharging exhaust from the cylinder, A turbocharger including a turbine wheel located in the exhaust passage and rotating in accordance with the exhaust flow in the exhaust passage, a compressor wheel located in the intake passage and rotating integrally with the turbine wheel, a bypass passage connecting the upstream and downstream portions of the exhaust passage with respect to the turbine wheel, and a wastegate valve for opening and closing the flow path of the bypass passage. An actuator that operates the wastegate valve according to the supplied power, This is applied to a control device that controls an internal combustion engine equipped with the following features: The control device, The actual boost pressure is obtained as the measured value of the boost pressure, which is the pressure in the downstream portion of the intake passage relative to the compressor wheel. When changing the opening of the wastegate valve, the change in power is made larger than when the change in the actual boost pressure during a predetermined period is a first value, compared to when the change in the actual boost pressure during the predetermined period is a second value that is greater than the first value. Make it run Control program for internal combustion engines.

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