Control device for internal combustion engine

Abstract

When the internal combustion engine is started, a processing device of the control device executes a first control for controlling the opening degree of a wastegate valve to be the opening degree of an inner peripheral surface of an insulating part on an extension line of a sealing surface of the wastegate valve. The processing device determines whether warm-up of the internal combustion engine is completed. The processing device terminates the first control when the warm-up is completed. Thereafter, the processing device starts second control for controlling the degree of opening of the wastegate valve in accordance with the target boost pressure of the internal combustion engine. The processing device continues the first control if the warm-up of the internal combustion engine is not completed. Thereafter, the processing device executes the series of processes again at each predetermined control cycle until the first control ends.

Description

Technical Field

[0001] The present invention relates to a control device for an internal combustion engine mounted on a vehicle including a turbocharger and an electrically heated catalyst device. Background Art

[0002] An electrically heated catalyst device is known that heats the catalyst carrier by energizing the catalyst carrier. The catalyst carrier is installed in a state of being electrically insulated from a tubular housing that accommodates the catalyst carrier. In such an electrically heated catalyst device, conductive particulate matter contained in the exhaust gas may accumulate on the insulating portion, thereby reducing the insulation between the catalyst carrier and the housing.

[0003] In order to suppress the accumulation of particulate matter on the insulating part, a technology using thermophoresis is disclosed. A catalyst device is described in Japanese Patent Application Laid-Open No. 2023-058325. The catalyst device suppresses the accumulation of particulate matter on the insulating part by using thermophoresis, which uses the temperature gradient in the space between the outer partition part whose outer peripheral surface is exposed to the outside air and the insulating part of the inner partition part in contact with the exhaust gas as a driving force. Summary of the invention

[0004] It is known that in an internal combustion engine equipped with a turbocharger, the temperature of the exhaust gas decreases when passing through the turbine impeller. Therefore, in the case of a vehicle equipped with a turbocharger, in the catalyst device, there is a possibility that a large temperature gradient that can suppress the accumulation of particulate matter by thermophoresis will not be generated between the insulating portion of the outer partition member and the inner partition member.

[0005] Means for solving the above-mentioned problems and their effects are described below.

[0006] A control device for an internal combustion engine for solving the above-mentioned problem controls the internal combustion engine, and the internal combustion engine comprises: a turbine impeller, which is arranged in an exhaust passage; a bypass passage, which branches off from the exhaust passage at a portion of the exhaust passage on the upstream side of the turbine impeller and merges with the exhaust passage at a portion of the exhaust passage on the downstream side of the turbine impeller; a catalyst device for exhaust gas purification, which is arranged in a portion of the exhaust passage on the downstream side of the merging position; and an exhaust bypass valve, which is arranged in a portion of the exhaust passage on the upstream side of the catalyst device and blocks an outlet of the bypass passage.

[0007] The catalyst device is an electrically heated catalyst device that heats a catalyst provided in an exhaust passage by supplying electricity.

[0008] A component for dividing an exhaust passage that guides exhaust gas to the catalyst comprises: an internal dividing component that supports the catalyst on the inner side in an electrically insulating state; and an external dividing component that is connected to the internal dividing component from the outside and covers the end of the exhaust upstream side of the internal dividing component from the outside in a radially separated state, thereby constituting a part of the outer contour of the exhaust passage.

[0009] The portion of the inner partition member covered by the outer partition member serves as an insulating portion continuous with the portion supporting the catalyst.

[0010] The control device for the internal combustion engine includes a processing device.

[0011] The processing device performs a first control to control the opening of the wastegate valve to an opening at which the inner peripheral surface of the insulating portion is located on an extension line of a sealing surface of the wastegate valve when the internal combustion engine is started.

[0012] Even when the temperature of the exhaust gas decreases due to passage through the bypass passage, the control device can maintain the insulation performance of the insulating portion. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will be described below with reference to the accompanying drawings, in which like symbols represent like elements, and in which:

[0014] Figure 1 It is a schematic diagram showing the structure of an internal combustion engine of a vehicle to which one embodiment of the control device for an internal combustion engine is applied.

[0015] Figure 2 It is a cross-sectional view of a bypass passage, a wastegate valve, and an electrically heated catalyst device in a vehicle to which the control device of the embodiment is applied.

[0016] Figure 3 This is a flowchart of the wastegate valve control executed by the control device of the first embodiment.

[0017] Figure 4 This is a flowchart of the wastegate valve control executed by the control device of the second embodiment.

[0018] Figure 5 This is a flowchart of the wastegate valve control executed by the control device in the modified example of the second embodiment. DETAILED DESCRIPTION

[0019] First embodiment

[0020] Below, refer to Figures 1 to 3 A first embodiment of the control device for an internal combustion engine will be described.

[0021] Structure of the Internal Combustion Engine 10

[0022] First, refer to Figure 1 The structure of the internal combustion engine 10 to be controlled by the control device 30 of the internal combustion engine 10 will be described. The internal combustion engine 10 includes a combustion chamber 11 for performing combustion of a mixture. In addition, the internal combustion engine 10 includes an intake passage 12 as an introduction passage for intake air to the combustion chamber 11, and an exhaust passage 13 as an exhaust passage for exhaust gas from the combustion chamber 11. Furthermore, the internal combustion engine 10 includes an injector 14 for injecting fuel into the intake air to form a mixture, and an ignition device 15 for igniting the mixture in the combustion chamber 11 by spark discharge. A throttle valve 16 is provided at a portion of the intake passage 12 on the downstream side of the compressor impeller 21. The throttle valve 16 adjusts the amount of intake air introduced into the combustion chamber 11 by changing the opening degree. Furthermore, the internal combustion engine 10 rotates a crankshaft 17 by the combustion of the mixture in the combustion chamber 11, thereby generating a driving force for the vehicle.

[0023] The internal combustion engine 10 is provided with a turbocharger 20. The turbocharger 20 has a compressor impeller 21 provided in the intake passage 12 and a turbine impeller 22 provided in the exhaust passage 13. The compressor impeller 21 is an impeller that compresses the intake air by rotating. The turbine impeller 22 is an impeller that receives the flow of the exhaust gas and rotates. The compressor impeller 21 and the turbine impeller 22 are connected via a turbine shaft 23. Thus, the compressor impeller 21 rotates in conjunction with the rotation of the turbine impeller 22.

[0024] The exhaust passage 13 is provided with a bypass passage 24 for allowing the exhaust gas to bypass the turbine impeller 22 and flow downstream. The bypass passage 24 branches from the exhaust passage 13 at a portion of the exhaust passage 13 on the upstream side of the turbine 22. The bypass passage 24 merges with the exhaust passage 13 at a portion of the exhaust passage 13 on the downstream side of the turbine 22.

[0025] A catalyst device 39 is provided at a position downstream of the confluence position of the bypass passage 24 and the exhaust passage 13. The catalyst device 39 includes a catalyst carrier 19 carrying a catalyst for exhaust purification inside. The catalyst device 39 is an electrically heated catalyst device that heats the catalyst carrier 19 provided in the exhaust passage 13 by energizing the catalyst carrier 19. The detailed structure of the catalyst device 39 will be described later.

[0026] The exhaust passage 13 is provided with a wastegate valve 25 for opening and closing the outlet of the bypass passage 24. The wastegate valve 25 is provided in the exhaust passage 13 at a position downstream of the confluence of the bypass passage 24 and the exhaust passage 13 and upstream of the catalyst device 39. The exhaust passage 13 is provided with an exhaust temperature sensor 18 for detecting the exhaust temperature. The exhaust temperature sensor 18 is provided in the exhaust passage 13 at a position downstream of the wastegate valve 25 and upstream of the catalyst device 39.

[0027] Configuration of the control device 30

[0028] The internal combustion engine 10 is controlled by a control device 30. The control device 30 includes a processing device 31 and a storage device 32. The storage device 32 stores programs and data for controlling the internal combustion engine 10. The processing device 31 controls the internal combustion engine 10 by reading the programs from the storage device 32 and executing them.

[0029] The detection results of various sensors for detecting the operating conditions of the internal combustion engine 10 are input to the control device 30. The sensors input to the control device 30 include an air flow meter 33, an intake air temperature sensor 34, a water temperature sensor 35, a crank angle sensor 36, a boost pressure sensor 37, an intake manifold pressure sensor 38, and an exhaust temperature sensor 18.

[0030] The air flow meter 33 is a sensor for detecting the flow rate of intake air flowing in the intake passage 12, that is, the intake flow rate. The intake air temperature sensor 34 is a sensor for detecting the temperature of the intake air taken into the intake passage 12, that is, the intake air temperature. The water temperature sensor 35 is a sensor for detecting the temperature of the cooling water of the internal combustion engine 10, that is, the engine water temperature. The crank angle sensor 36 is a sensor for detecting the rotation angle of the crankshaft 17, that is, the crank angle. The boost pressure sensor 37 is a sensor for detecting the boost pressure, which is the pressure of the intake air in the portion of the intake passage 12 downstream of the compressor impeller 21 and upstream of the throttle valve 16. The intake manifold pressure sensor 38 is a sensor for detecting the pressure of the intake air in the portion of the intake passage 12 downstream of the throttle valve 16, that is, the intake manifold pressure. The processing device 31 of the control device 30 controls the opening of the wastegate valve 25 based on the detection results of these sensors. In the present embodiment, the processing device 31 controls the fuel injection amount and fuel injection timing of the injector 14 , the ignition timing of the ignition device 15 , the throttle opening, and the like based on the detection results of these sensors.

[0031] Structure of turbocharger 20

[0032] Next, refer to Figure 2 The structure of the turbocharger 20 will be described.

[0033] like Figure 2As shown, in the turbocharger 20, two swirl passages 121, a storage space 122, an exhaust outlet 123, and two bypass passages 24 are divided as spaces for exhaust gas circulation. Figure 2 2, a bypass passage 24 is shown. The vortex passage 121 extends in an arc shape so as to surround the turbine impeller 22. The upstream end of the vortex passage 121 is connected to the turbine impeller 22. Figure 1 The downstream end of the vortex passage 121 is connected to the housing space 122. The housing space 122 is a space where the turbine impeller 22 is located. The housing space 122 is connected to the exhaust outlet 123. The downstream end of the exhaust outlet 123 is connected to the introduction pipe 170. The introduction pipe 170 is a part of the exhaust passage 13. Each bypass passage 24 connects the vortex passage 121 to the exhaust outlet 123.

[0034] The wastegate valve 25 is provided at the outlet of the bypass passage 24. The bypass passage 24 is opened and closed by the wastegate valve 25. That is, when the wastegate valve 25 is open, the bypass passage 24 bypasses the turbine 22 and communicates the portion on the exhaust gas upstream side of the turbine 22 with the portion on the exhaust gas downstream side of the turbine 22. The larger the opening of the wastegate valve 25 is, the greater the flow rate of the exhaust gas bypassing the turbine impeller 22. As a result, the boost pressure generated by the driving of the turbocharger 20 becomes lower.

[0035] Structure of the catalyst device 39

[0036] Next, the structure of the catalyst device 39 will be described. Figure 2 As shown, the catalyst device 39 includes a catalyst carrier 19 carrying a catalyst for purifying exhaust gas. The catalyst carrier 19 is a porous body. For example, the catalyst carrier 19 is a structure having a honeycomb structure that partitions a plurality of passages extending in the flow direction of the exhaust gas. The catalyst carried on the catalyst carrier 19 is, for example, a three-way catalyst.

[0037] The catalyst device 39 includes a shell 240 which is a tube for accommodating the catalyst carrier 19. The shell 240 is a tube formed of a metal material. For example, the shell 240 is formed of stainless steel. The end surface on the exhaust upstream side of the catalyst carrier 19 accommodated in the shell 240 is set as the catalyst upstream end 210. The portion of the shell 240 on the exhaust upstream side bounded by the catalyst upstream end 210 is set as the end 241. The end 241 is continuous from the shell 240. The end 241 protrudes toward the exhaust upstream side more than the catalyst upstream end 210. The surface of the end 241 is covered with an insulator. An insulating layer is formed at the end 241 by an insulator covering the entire surface of the end 241. In this way, the surface of the end 241 becomes an insulating portion 242. That is, the insulating portion 242 becomes electrically insulated from the catalyst carrier 19. The shell 240, the end 241 and the insulating portion 242 correspond to the internal partitioning components.

[0038] The catalyst device 39 includes a pair of electrodes 220 for supplying electricity to the catalyst carrier 19. An electrode insertion hole 221 for inserting the electrode 220 is provided on the shell 240. The electrode insertion hole 221 is closed by an electrode holder 222. The electrode 220 is connected to the catalyst carrier 19. By applying a voltage between the pair of electrodes 220, a current flows through the catalyst carrier 19. When the current flows through the catalyst carrier 19, the catalyst carrier 19 generates heat due to the resistance of the catalyst carrier 19. That is, the catalyst carrier 19 is a material that generates heat according to the resistance when electricity is supplied. For example, the catalyst carrier 19 is a ceramic made of silicon carbide. The electrode 220 connected to the catalyst carrier 19 protrudes outside the shell 240 through the electrode insertion hole 221. The electrode holder 222 is an insulator with low conductivity. The electrode 220 is supported by the electrode holder 222 so that the current does not flow to the shell 240.

[0039] The catalyst device 39 includes a mat 230 for fixing the catalyst carrier 19 to the housing 240. The housing 240 supports the catalyst carrier 19 via the mat 230. The mat 230 is an insulator with low electrical conductivity. For example, the mat 230 is an inorganic fiber with aluminum oxide as a main component. By covering the catalyst carrier 19 with the mat 230, when the catalyst carrier 19 is energized, electricity does not flow through the housing 240. That is, the housing 240 is electrically insulated from the catalyst carrier 19.

[0040] Connection between turbocharger 20 and catalyst device 39

[0041] Next, the connection between the turbocharger 20 and the catalyst device 39 will be described.

[0042] like Figure 2 As shown, the shell 240 and the introduction pipe 170 are connected by the first connecting pipe 310 and the second connecting pipe 320. The first connecting pipe 310 and the second connecting pipe 320 constitute a part of the outer contour of the exhaust passage 13. That is, the first connecting pipe 310 and the second connecting pipe 320 correspond to the external partitioning member. The first connecting pipe 310 is connected to the exhaust gas downstream side of the introduction pipe 170 from the outside at the first connecting portion 331. The second connecting pipe 320 is connected to the exhaust gas downstream side of the shell 240 from the outside at the second connecting portion 332. The first connecting pipe 310 is connected to the second connecting pipe 320 from the inside at the third connecting portion 333. The space between the introduction pipe 170 and the insulating portion 242 is sealed by joining the introduction pipe 170 and the shell 240 with the external partitioning member.

[0043] The inlet pipe 170 is inserted into the shell 240. Moreover, the inlet pipe 170 and the insulating portion 242 continuous from the shell 240 are separated in the radial direction to form a double tube structure. Furthermore, the portion between the first connecting portion 331 and the second connecting portion 332 in the external partition member is separated in the radial direction relative to the inlet pipe 170 and the insulating portion 242 to form a double tube structure. In addition, the inlet pipe 170, the insulating portion 242 and the external partition member are separated in the radial direction to form a three-layer tube structure. As described above, the catalyst device 39 has a three-layer tube structure and a plurality of double tube structures in a portion on the upstream side of the catalyst carrier 19 in the exhaust direction. The three-layer tube structure and the plurality of double tube structures form a labyrinth portion 340 into which the exhaust gas can flow. The labyrinth portion 340 is connected to the exhaust passage 13 through the gap between the inlet pipe 170 and the insulating portion 242.

[0044] Regarding the control of the wastegate valve 25 by the processing device 31

[0045] The processing device 31 performs either the first control or the second control on the wastegate valve 25. When the internal combustion engine 10 is started, the processing device 31 performs the first control.

[0046] like Figure 2 As shown, the first control is a control in which the processing device 31 changes the opening of the wastegate valve 25 to an opening in which the inner peripheral surface 242A of the insulating portion 242 is located on an extension line 410 of the sealing surface 400 of the wastegate valve 25. The sealing surface 400 is a surface that blocks the outlet of the bypass passage 24 in the wastegate valve 25. The sealing surface 400 of the wastegate valve 25 is a flat surface.

[0047] On the other hand, the second control is a control in which the processing device 31 changes the opening of the wastegate valve 25 according to the target supercharging pressure of the internal combustion engine 10. In the second control, the processing device 31 sets the target supercharging pressure according to the operating condition of the internal combustion engine 10. Furthermore, the processing device 31 controls the opening of the wastegate valve 25 in order to set the supercharging pressure to the target supercharging pressure.

[0048] Figure 3 2 shows the flow of a series of processes executed by the processing device 31. The series of processes are executed by the processing device 31 together with the completion of the start of the internal combustion engine 10. The series of processes are repeatedly executed in each predetermined control cycle until the processing device 31 completes the execution of the second control.

[0049] When the series of processes starts, the processing device 31 first determines whether the warm-up of the internal combustion engine 10 is completed in the process of S100. For example, the processing device 31 determines that the warm-up of the internal combustion engine 10 is completed when the engine water temperature of the internal combustion engine 10 obtained from the water temperature sensor 35 is equal to or higher than a predetermined value.

[0050] If the warm-up of the internal combustion engine 10 is not completed (S100: No), the process proceeds to S110. In the process of S110, the processing device 31 performs the first control. When the process of S110 is performed, the processing device 31 temporarily terminates the series of processes. Thereafter, the processing device 31 performs the series of processes again in each predetermined control cycle.

[0051] On the other hand, when the warm-up of the internal combustion engine 10 is completed (S100: Yes), the process proceeds to S120. In the process of S120, the processing device 31 starts the second control without executing the first control. In the process of S120, the processing device 31 ends the first control while executing the first control. Thereafter, the processing device 31 starts the second control. When the process of S120 is executed, the processing device 31 ends the series of processes.

[0052] That is, the processing device 31 executes the first control until the warm-up of the internal combustion engine 10 is completed. When the warm-up of the internal combustion engine 10 is completed, the first control is terminated and the second control is executed.

[0053] Function of the first embodiment

[0054] The processing device 31 of the control device 30 can make the exhaust gas blown out from the outlet of the bypass passage 24 hit the inner peripheral surface 242A of the insulating portion 242 as the internal partition member in a concentrated manner by controlling the opening of the wastegate valve 25 when the internal combustion engine 10 is started. As a result, the temperature of the insulating portion 242 becomes easier to rise compared to the case where the exhaust gas blown out from the outlet of the bypass passage 24 does not hit the inner peripheral surface 242A of the insulating portion 242 in a concentrated manner. As a result, the temperature difference between the insulating portion 242 and the external partition member increases. By increasing the temperature difference between the insulating portion 242 and the external partition member, the temperature gradient between the insulating portion 242 and the external partition member increases. If the temperature gradient increases, thermophoresis, which uses the temperature gradient as a driving force, becomes active. As a result, the particulate matter PM easily moves from the vicinity of the insulating portion 242 as the high temperature side toward the external partition member as the low temperature side through thermophoresis. Therefore, the accumulation of particulate matter PM at the insulating portion 242 is suppressed.

[0055] Effects of the First Embodiment

[0056] (1) The control device 30 can maintain the insulation performance of the insulating portion 242 even when the temperature of the exhaust gas is lowered via the bypass passage 24 .

[0057] (2) The processing device 31 of the control device 30 performs the following first control: the opening of the wastegate valve 25 is controlled to be an opening at which the inner peripheral surface 242A of the insulating portion 242 is located on the extension line 410 of the sealing surface 400 of the wastegate valve 25. In addition, the processing device 31 of the control device 30 performs the following second control: the opening of the wastegate valve 25 is controlled according to the target supercharging pressure of the internal combustion engine 10. When the warm-up of the internal combustion engine 10 is completed, the combustion is stabilized and the amount of particulate matter PM contained in the exhaust gas decreases. The temperature of the exhaust gas passing through the bypass passage 24 also increases. Therefore, the above-mentioned processing device 31 ends the first control when the warm-up of the internal combustion engine 10 is completed. Then, the processing device 31 performs the second control. As a result, the control device 30 can transfer the control of the wastegate valve 25 from the first control to the second control at an appropriate timing. Moreover, the control device 30 can perform the normal supercharging pressure control for achieving the target supercharging pressure in the second control.

[0058] Modifications of the First Embodiment

[0059] This embodiment can be implemented by being modified as follows. This embodiment and the following modified examples can be implemented in combination with each other within the range that there is no technical contradiction.

[0060] When determining whether warm-up of the internal combustion engine 10 is completed, the processing device 31 of the control device 30 may determine that warm-up is completed when the lubricating oil temperature in the internal combustion engine 10 is equal to or higher than a predetermined temperature. The processing device 31 may obtain information on the lubricating oil temperature from a lubricating oil temperature sensor.

[0061] When determining whether warm-up of the internal combustion engine 10 is completed, the processing device 31 may determine that warm-up is completed when the cumulative intake air flow rate from the start of operation is equal to or greater than a predetermined value. The processing device 31 may calculate the cumulative intake air flow rate based on the intake air flow rate obtained from the air flow meter 33 .

[0062] When determining whether the warm-up of the internal combustion engine 10 is completed, the processing device 31 may correct the predetermined value of the cumulative intake flow rate for determining that the warm-up is completed based on the intake air temperature detected by the intake air temperature sensor 34. For example, when the intake air temperature is low, the processing device 31 may correct the predetermined value of the cumulative intake flow rate for determining that the warm-up of the internal combustion engine 10 is completed to a higher value.

[0063] Second embodiment

[0064] Next, refer to Figure 4 A second embodiment will be described. The second embodiment will be described mainly focusing on differences from the first embodiment. In the second embodiment, the processing device 31 of the control device 30 changes the control of the wastegate valve 25 based on a determination criterion different from that of the first embodiment.

[0065] In the second embodiment, the processing device 31 executes the first control when the internal combustion engine 10 is started, similarly to the first embodiment.

[0066] Figure 4 The flow of a series of processes executed by the processing device 31 in the second embodiment is shown. The series of processes is executed by the processing device 31 together with the completion of the start of the internal combustion engine 10. The series of processes is repeatedly executed in each predetermined control cycle until the processing device 31 completes the execution of the first control.

[0067] When the series of processing starts, the processing device 31 first determines in the process of S200 whether the first control has continued for a predetermined time or longer.

[0068] When the first control does not continue for more than a predetermined time (S200: No), the process enters S210. In the process of S210, the processing device 31 estimates whether the temperature of the insulating part 242 is above a predetermined temperature. For example, when the amount of heat received by the insulating part 242 from the exhaust gas is above a predetermined value, the processing device 31 may also estimate that the insulating part 242 is above a predetermined temperature. The amount of heat received by the insulating part 242 from the exhaust gas is related to the flow rate of the exhaust gas colliding with the insulating part 242. Moreover, the flow rate of the exhaust gas is related to the intake air flow rate. Therefore, the processing device 31 determines whether the amount of heat received by the insulating part 242 from the exhaust gas is above a predetermined value based on the cumulative intake air flow rate calculated according to the intake air flow rate obtained from the air flow meter 33.

[0069] When it is estimated that the temperature of the insulating part 242 is higher than the predetermined temperature (S210: Yes), the process proceeds to S230. In the process of S230, the processing device 31 ends the first control. Thereafter, the processing device 31 starts the second control. When the process of S230 is executed, the processing device 31 ends the series of processes. When it is estimated that the temperature of the insulating part 242 is lower than the predetermined temperature (S210: No), the process proceeds to S220. In the process of S220, the processing device 31 executes the first control. When the process of S220 is executed, the processing device 31 temporarily ends the series of processes. Thereafter, the processing device 31 executes the series of processes again at each predetermined control cycle.

[0070] On the other hand, if the first control continues for a predetermined time or longer (S200: Yes), the process proceeds to S230. In the process of S230, the processing device 31 ends the first control. Thereafter, the processing device 31 starts the second control. When the process of S230 is executed, the processing device 31 ends the series of processes.

[0071] Effects of the Second Embodiment

[0072] It is considered that if the temperature of the insulating portion 242 is sufficiently high, even if the first control is terminated, the temperature gradient between the insulating portion 242 and the external partition member can be maintained at a sufficient level for thermophoresis of the particulate matter PM.

[0073] Therefore, the processing device 31 of the control device 30 ends the first control on the condition that the temperature of the insulating portion 242 is equal to or higher than a predetermined temperature. Next, the processing device 31 performs the second control.

[0074] Effects of the Second Embodiment

[0075] (1) The control device 30 can control the internal combustion engine 10 so that the target supercharging pressure of the internal combustion engine 10 is satisfied while maintaining the insulation performance of the insulating portion 242 .

[0076] (2) The processing device 31 of the control device 30 ends the first control when the first control lasts for more than a predetermined time. Thereafter, the processing device 31 starts the second control. When the first control lasts for more than a predetermined time, it is considered that the temperature gradient between the insulating portion 242 and the external partition member can be maintained at a sufficient size for thermophoresis of the particulate matter PM. Therefore, the processing device 31 ends the first control on the condition that the first control lasts for more than a predetermined time. Next, the processing device 31 implements the second control. As a result, the control device 30 can control the internal combustion engine 10 in a manner that maintains the insulation of the insulating portion 242 while satisfying the target boost pressure of the internal combustion engine 10.

[0077] Modification example of the second embodiment

[0078] The second embodiment described above can be implemented by modification as follows. The present embodiment and the following modification examples can be implemented in combination with each other within the scope of no technical contradiction.

[0079] When the warm-up of the internal combustion engine 10 is completed, the combustion is stabilized and the amount of particulate matter PM contained in the exhaust gas is reduced. The temperature of the exhaust gas passing through the bypass passage 24 is also increased. Therefore, the processing device 31 of the control device 30 may also set the length of time for which it is determined in the process of S200 that the first control has continued for more than a predetermined time to a length that can determine that the warm-up of the internal combustion engine 10 is completed. Thus, the processing device 31 can shift the control of the wastegate valve 25 from the first control to the second control at an appropriate timing.

[0080] The processing device 31 may omit the process of S210 . That is, the processing device 31 may continue the first control ( S220 ) only on the condition that the duration of the first control is less than a predetermined time ( S200 : No).

[0081] The processing device 31 may use information other than the integrated intake air flow rate to estimate whether the temperature of the insulating portion 242 is above a predetermined temperature. For example, when the detection value of the exhaust temperature sensor 18 is above a certain temperature, the processing device 31 may estimate that the temperature of the insulating portion 242 is above the predetermined temperature.

[0082] The processing device 31 may omit the processing of S200. That is, the processing device 31 may terminate the first control only when the temperature of the insulating portion 242 is higher than the predetermined temperature (S210: Yes). When the first control is terminated, the processing device 31 starts the second control (S230). Furthermore, the processing device 31 may continue to execute the first control (S220) only when the temperature of the insulating portion 242 is lower than the predetermined temperature (S210: No).

[0083] The processing device 31 may also control the wastegate valve 25 after switching to the second control so that the exhaust gas passing through the bypass passage 24 hits the inner peripheral surface 242A of the insulating portion 242. Figure 5 As shown, when the temperature of insulating portion 242 is lower than the lower limit temperature, processing device 31 may control the opening of wastegate valve 25 so that the exhaust gas collides with inner peripheral surface 242A of insulating portion 242 .

[0084] Figure 5 The flow of a series of processes executed by the processing device 31 when the second control is implemented is shown. When the series of processes are started, the processing device 31 first determines whether the temperature of the insulating portion 242 is lower than the lower limit temperature in the process of S300.

[0085] When the temperature of insulating portion 242 is lower than the lower limit temperature (S300: Yes), the process proceeds to S310. When the temperature of insulating portion 242 is higher than the lower limit temperature (S300: No), the processes of S310 to S330 are not performed and the process ends immediately.

[0086] In the process of S310, the processing device 31 ends the second control. Thereafter, the processing device 31 starts the first control. Then, the process proceeds to S320. In the process of S320, the processing device 31 determines whether the end condition of the first control is satisfied. For example, when it is estimated that the temperature of the insulating portion 242 is above a predetermined temperature, the processing device determines that the end condition of the first control is satisfied. For example, when the first control lasts for more than a predetermined time, the processing device 31 determines that the end condition of the first control is satisfied.

[0087] If the end condition of the first control is satisfied (S320: Yes), the process proceeds to S330. In the process of S330, the processing device 31 ends the first control. Thereafter, the processing device 31 restarts the second control. When the process of S230 is executed, the processing device 31 ends the series of processes.

[0088] When the end condition of the first control is not satisfied ( S320 : NO), the processing device 31 repeatedly executes the process of S320 in each predetermined control cycle.

[0089] During the period when the processing device 31 implements the second control, the flow of the exhaust gas blown out from the outlet of the bypass passage 24 will not be concentrated on the inner peripheral surface 242A of the insulating portion 242. Therefore, during the period when the processing device 31 implements the second control, the temperature of the insulating portion 242 may decrease. The processing device 31 may also terminate the second control on the condition that it is estimated that the temperature of the insulating portion 242 is lower than the lower limit temperature. When the second control is terminated, the processing device 31 implements the first control. Thus, the processing device 31 can maintain the temperature of the insulating portion 242 at a temperature that exerts the effect of thermophoresis.

[0090] Other changes

[0091] In addition, the above-mentioned embodiments include the following elements as commonly changeable elements. The following modification examples can be implemented in combination with each other within the scope of no technical contradiction.

[0092] The vehicle to which the control device 30 is applied is not limited to a vehicle in which the thrust generating device is only the internal combustion engine 10. For example, a series / parallel hybrid electric vehicle may be used. For example, a parallel hybrid electric vehicle may be used. For example, a series hybrid electric vehicle may be used.

[0093] The control device 30 may also be applied to an internal combustion engine 10 including a catalyst device 39 that does not have a triple pipe structure. For example, the control device 30 may also be applied to an internal combustion engine 10 including a catalyst device 39 in which the introduction pipe 170 is not disposed inside the casing 240 .

[0094] The processing device 31 of the control device 30 starts the first control when the internal combustion engine 10 is started. Here, the start of the internal combustion engine 10 is not limited to when the ignition switch is switched from OFF to ON. For example, after the internal combustion engine 10 is stopped by executing the idle stop process, the control device 30 may start the first control when the internal combustion engine 10 is restarted after the idle stop process is completed. For example, after the internal combustion engine 10 is stopped in a hybrid electric vehicle, the control device 30 may start the first control when the internal combustion engine 10 is restarted according to the condition of the vehicle.

Claims

1. A control device for an internal combustion engine, for controlling the internal combustion engine, The internal combustion engine comprises: a turbine impeller disposed in an exhaust passage; a bypass passage branching from the exhaust passage at a portion of the exhaust passage on the upstream side of the turbine impeller and merging with the exhaust passage at a portion of the exhaust passage on the downstream side of the turbine impeller; a catalyst device for exhaust gas purification disposed in a portion of the exhaust passage on the downstream side of the merging position; and a wastegate valve disposed in a portion of the exhaust passage on the upstream side of the catalyst device and closing an outlet of the bypass passage. The catalyst device is an electrically heated catalyst device that heats a catalyst disposed in the exhaust passage by supplying electricity. The component for dividing the exhaust passage for guiding the exhaust gas to the catalyst comprises: an inner dividing component that supports the catalyst on the inner side in an electrically insulated state; and an outer dividing component that is connected to the inner dividing component from the outside and covers the end of the exhaust gas upstream side of the inner dividing component from the outside in a radially separated state, constituting a part of the outer contour of the exhaust passage. The portion of the inner partition member covered by the outer partition member serves as an insulating portion continuous with the portion supporting the catalyst. The control device for an internal combustion engine is applied to the above-mentioned internal combustion engine, wherein: The control device for the internal combustion engine comprises a processing device, The processing device performs a first control to control the opening of the wastegate valve to an opening at which the inner peripheral surface of the insulating portion is located on an extension line of a sealing surface of the wastegate valve when the internal combustion engine is started.

2. The control device for an internal combustion engine according to claim 1, wherein: When warm-up of the internal combustion engine is completed, the processing device terminates the first control and starts a second control for controlling the opening degree of the wastegate valve according to a target supercharging pressure of the internal combustion engine.

3. The control device for an internal combustion engine according to claim 1, wherein: When the processing device estimates that the temperature of the insulating portion is equal to or higher than a predetermined temperature, the processing device ends the first control and starts a second control for controlling the opening of the wastegate valve according to a target supercharging pressure of the internal combustion engine.

4. The control device for an internal combustion engine according to claim 1, wherein: When the first control continues for a predetermined time or longer, the first control is ended and a second control is started in which the opening degree of the wastegate valve is controlled according to a target supercharging pressure of the internal combustion engine.

5. The control device for an internal combustion engine according to claim 3 or 4, wherein: When it is estimated that the temperature of the insulating portion is lower than the lower limit temperature, the second control is terminated and the first control is executed.

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