Internal combustion engine control device

Abstract

To provide an internal combustion engine control device mounted on a vehicle including a turbocharger and an electric heating type catalyst device.SOLUTION: A processing unit for a control device executes a first control controlling the opening of a waste gate valve to become an opening where the inner peripheral surface of an insulation part is positioned on an extension line of a seal surface of the waste gate valve, when an internal combustion engine starts. The processing device determines whether or not warming-up of the internal combustion engine is completed (step S100). The processing device finishes the first control when the warm-up of the internal combustion engine is completed (step S100:YES). Thereafter, the processing device starts a second control controlling the opening of the waste gate valve in accordance with a target boost pressure of the internal combustion engine (step S120). The processing device continues the first control (step S110) when the warm-up of the internal combustion engine is not completed (step S100:NO). Thereafter, the processing device executes again a series of processing for each predetermined control cycle until the first control is finished.SELECTED DRAWING: Figure 3

Description

[Technical field]

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

[0002] Electrically heated catalyst devices are known that heat the catalyst carried by passing electricity through the catalyst carrier to generate heat. The catalyst carrier is attached in an electrically insulated state to a tubular case that houses the catalyst carrier. In such electrically heated catalyst devices, there is a risk that the insulation between the catalyst carrier and the case will be reduced due to conductive particulate matter contained in the exhaust gas accumulating on the insulating portion.

[0003] A technology that utilizes thermophoresis to suppress the accumulation of particulate matter on the insulating part has been disclosed. Patent Document 1 describes a catalytic device that suppresses the accumulation of particulate matter on the insulating part by thermophoresis driven by a temperature gradient in the space between an outer partition member whose outer circumferential surface is exposed to the outside air and an insulating part of an inner partition member that comes into contact with exhaust gas. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2023-058325 A Summary of the Invention [Problem to be solved by the invention]

[0005] It is known that in internal combustion engines with turbochargers, the temperature of the exhaust gas drops as it passes through the turbine wheel, so in vehicles with turbochargers, the catalytic converter may not have a large enough temperature gradient between the outer partition member and the insulating portion of the inner partition member to induce thermophoresis sufficient to inhibit particulate matter deposition. [Means for solving the problem]

[0006] The means for solving the above problems and their effects will be described below. The control device for an internal combustion engine for solving the above problem controls an internal combustion engine including a turbine wheel installed in an exhaust passage, a bypass passage branched from the exhaust passage at a position upstream of the turbine wheel in the exhaust passage and merging with the exhaust passage at a position downstream of the turbine wheel in the exhaust passage, a catalytic device for exhaust purification installed in a portion of the exhaust passage downstream of the merging position, and a wastegate valve installed in a portion of the exhaust passage upstream of the catalytic device and closing an outlet of the bypass passage. The catalytic device is an electrically heated catalytic device in which a catalyst provided in the exhaust passage is heated by passing electricity. The members that partition the exhaust passage that guides exhaust gas to the catalyst include an internal partition member that supports the catalyst inside in an electrically insulated state, and an external partition member that is connected to the internal partition member from the outside and covers an end of the internal partition member on the exhaust upstream side from the outside in a radially spaced state to form a part of the outer shell of the exhaust passage. The portion of the internal partition member that is covered by the external partition member is an insulating portion that is continuous with a portion that supports the catalyst.

[0007] The control device for the internal combustion engine includes a processing device that executes a first control for controlling an opening degree of the wastegate valve to an opening degree such that an inner circumferential surface of the insulating portion is positioned on an extension line of a sealing surface of the wastegate valve when the internal combustion engine is started. Effect of the Invention

[0008] The control device can maintain the insulation properties of the insulating portion even when the temperature of the exhaust gas decreases as the exhaust gas passes through the bypass passage. [Brief description of the drawings]

[0009] [Figure 1]FIG. 1 is a schematic diagram showing the configuration of an internal combustion engine of a vehicle to which an embodiment of a control device for an internal combustion engine is applied. [Diagram 2] FIG. 2 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. [Diagram 3] FIG. 3 is a flowchart of the wastegate valve control executed by the control device of the first embodiment. [Figure 4] FIG. 4 is a flowchart of wastegate valve control executed by the control device of the second embodiment. [Diagram 5] FIG. 5 is a flowchart of wastegate valve control executed by the control device in a modified example of the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] (First embodiment) Hereinafter, a first embodiment of a control device for an internal combustion engine will be described with reference to FIGS. 1 to 3. FIG. <Configuration of the internal combustion engine 10> First, the configuration of the internal combustion engine 10 controlled by the control device 30 of the internal combustion engine 10 will be described with reference to FIG. 1. The internal combustion engine 10 includes a combustion chamber 11 in which a mixture is burned. The internal combustion engine 10 also includes an intake passage 12 which is a passage through which intake air is introduced into the combustion chamber 11, and an exhaust passage 13 which is a passage through which exhaust gas is discharged from the combustion chamber 11. The internal combustion engine 10 also includes an injector 14 which injects fuel into the intake air to form a mixture, and an ignition device 15 which ignites the mixture in the combustion chamber 11 by spark discharge. A throttle valve 16 is installed in a portion of the intake passage 12 downstream of the compressor wheel 21. The throttle valve 16 adjusts the amount of intake air introduced into the combustion chamber 11 according to a change in the opening degree. The internal combustion engine 10 generates a driving force for a vehicle by rotating a crankshaft 17 by the combustion of the mixture in the combustion chamber 11.

[0011] The internal combustion engine 10 is equipped with a turbocharger 20. The turbocharger 20 has a compressor wheel 21 installed in the intake passage 12 and a turbine wheel 22 installed in the exhaust passage 13. The compressor wheel 21 is an impeller that compresses the intake air as it rotates. The turbine wheel 22 is an impeller that rotates by receiving the exhaust flow. The compressor wheel 21 and the turbine wheel 22 are connected via a turbine shaft 23. As a result, the compressor wheel 21 rotates in conjunction with the rotation of the turbine wheel 22.

[0012] The exhaust passage 13 is provided with a bypass passage 24, which is a passage for directing exhaust gas downstream while bypassing the turbine wheel 22. The bypass passage 24 branches off from the exhaust passage 13 at a location in the exhaust passage 13 upstream of the turbine wheel 22. The bypass passage 24 merges with the exhaust passage 13 at a location in the exhaust passage 13 downstream of the turbine wheel 22.

[0013] A catalytic device 39 is provided downstream of the joining position of the bypass passage 24 and the exhaust passage 13. Inside the catalytic device 39, a catalyst carrier 19 carrying a catalyst for purifying exhaust gas is provided. The catalytic device 39 is an electrically heated catalytic device in which the catalyst carrier 19 provided in the exhaust passage 13 is heated by passing electricity through it. The detailed configuration of the catalytic device 39 will be described later.

[0014] A wastegate valve 25 that opens and closes the outlet of the bypass passage 24 is provided in the exhaust passage 13. The wastegate valve 25 is installed downstream of a junction of the bypass passage 24 and the exhaust passage 13 in the exhaust passage 13, and upstream of the catalytic device 39. An exhaust temperature sensor 18 that detects the exhaust temperature is provided in the exhaust passage 13. The exhaust temperature sensor 18 is installed downstream of the wastegate valve 25 in the exhaust passage 13, and upstream of the catalytic device 39.

[0015] <Configuration of the control device 30> 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 and executing the programs from the storage device 32.

[0016] The control device 30 receives detection results from various sensors for detecting the operating conditions of the internal combustion engine 10. 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 the exhaust temperature sensor 18.

[0017] The air flow meter 33 is a sensor that detects the intake air flow rate, which is the flow rate of the intake air flowing through the intake passage 12. The intake air temperature sensor 34 is a sensor that detects the intake air temperature, which is the temperature of the intake air taken into the intake passage 12. The water temperature sensor 35 is a sensor that detects the engine water temperature, which is the temperature of the cooling water of the internal combustion engine 10. The crank angle sensor 36 is a sensor that detects the crank angle, which is the rotation angle of the crankshaft 17. The boost pressure sensor 37 is a sensor that detects the boost pressure, which is the pressure of the intake air in a portion of the intake passage 12 downstream of the compressor wheel 21 and upstream of the throttle valve 16. The intake manifold pressure sensor 38 is a sensor that detects the intake manifold pressure, which is the pressure of the intake air in a portion of the intake passage 12 downstream of the throttle valve 16. The processing device 31 of the control device 30 controls the opening degree of the wastegate valve 25 based on the detection results of these sensors. Additionally, in this 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, etc., based on the detection results of these sensors.

[0018] <Configuration of turbocharger 20> Next, the configuration of the turbocharger 20 will be described with reference to FIG. As shown in FIG. 2, the turbocharger 20 is divided into two scroll passages 121, an accommodation space 122, an exhaust outlet 123, and two bypass passages 24 as spaces through which the exhaust gas flows. Note that FIG. 2 illustrates one bypass passage 24. The scroll passage 121 extends in an arc shape so as to surround the turbine wheel 22. The upstream end of the scroll passage 121 is connected to the exhaust passage 13 shown in FIG. 1. The downstream end of the scroll passage 121 is connected to the accommodation space 122. The accommodation space 122 is a space in which the turbine wheel 22 is located. The accommodation space 122 is connected to the exhaust outlet 123. The downstream end of the exhaust outlet 123 is connected to an introduction pipe 170. The introduction pipe 170 is a part of the exhaust passage 13. Each bypass passage 24 connects the scroll passage 121 and the exhaust outlet 123.

[0019] 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 wheel 22 to connect a portion of the exhaust upstream of the turbine wheel 22 with a portion of the exhaust downstream of the turbine wheel 22. The larger the opening of the wastegate valve 25, the greater the flow rate of the exhaust that bypasses the turbine wheel 22. As a result, the boost pressure caused by driving the turbocharger 20 decreases.

[0020] <Configuration of catalytic converter 39> Next, the configuration of the catalytic converter 39 will be described. As shown in Fig. 2, the catalytic converter 39 includes a catalyst carrier 19 on which a catalyst for purifying exhaust gas is supported. The catalyst carrier 19 is a porous body. For example, the catalyst carrier 19 is a structure having a honeycomb structure in which a plurality of passages extending in the exhaust gas flow direction are defined. The catalyst supported on the catalyst carrier 19 is, for example, a three-way catalyst.

[0021] The catalytic device 39 includes a case 240, which is a tube that houses the catalyst carrier 19. The case 240 is a tube formed of a metal material. For example, the case 240 is formed of stainless steel. The end surface of the catalyst carrier 19 housed in the case 240 on the exhaust upstream side is the catalyst upstream end 210. The part of the case 240 on the exhaust upstream side, which is separated by the catalyst upstream end 210, is the end 241. The end 241 is continuous with the case 240. The end 241 protrudes further upstream in the exhaust than the catalyst upstream end 210. The surface of the end 241 is covered with an insulator. An insulating layer is formed on the end 241 by the insulator that covers the entire surface of the end 241. In this way, the surface of the end 241 is the insulating portion 242. That is, the insulating portion 242 is electrically insulated from the catalyst carrier 19. The case 240, the end 241, and the insulating portion 242 correspond to an internal partition member.

[0022] The catalytic device 39 includes a pair of electrodes 220 for passing electricity through the catalyst carrier 19. An electrode insertion hole 221 into which the electrode 220 is inserted is opened in the case 240. The electrode insertion hole 221 is closed by an electrode holding portion 222. The electrode 220 is connected to the catalyst carrier 19. A current flows through the catalyst carrier 19 by applying a voltage between the pair of electrodes 220. When a current flows through the catalyst carrier 19, the catalyst carrier 19 generates heat due to the electrical resistance of the catalyst carrier 19. That is, the catalyst carrier 19 is a material that generates heat according to the electrical resistance when electricity is passed through it. For example, the catalyst carrier 19 is a ceramic material made of silicon carbide. The electrode 220 connected to the catalyst carrier 19 protrudes outside the case 240 through the electrode insertion hole 221. The electrode holding portion 222 is an insulator with low electrical conductivity. The electrode holding portion 222 supports the electrode 220, so that no current flows through the case 240.

[0023] The catalyst device 39 includes a mat 230 that fixes the catalyst carrier 19 to a case 240. The case 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 whose main component is alumina. The catalyst carrier 19 is covered with the mat 230, so that electricity does not flow through the case 240 when electricity is applied to the catalyst carrier 19. In other words, the case 240 is electrically insulated from the catalyst carrier 19.

[0024] <Connection between turbocharger 20 and catalytic converter 39> Next, the connection between the turbocharger 20 and the catalytic converter 39 will be described. As shown in FIG. 2, the case 240 and the introduction pipe 170 are connected by a first connection pipe 310 and a second connection pipe 320. The first connection pipe 310 and the second connection pipe 320 form a part of the outer shell of the exhaust passage 13. That is, the first connection pipe 310 and the second connection pipe 320 correspond to an external partition member. The first connection pipe 310 is connected from the outside to the exhaust downstream side of the introduction pipe 170 at a first connection part 331. The second connection pipe 320 is connected from the outside to the exhaust downstream side of the insulating part 242 of the case 240 at a second connection part 332. The first connection pipe 310 is connected to the second connection pipe 320 from the inside at a third connection part 333. The external partition member is joined to the introduction pipe 170 and the case 240, so that the space between the introduction pipe 170 and the insulating part 242 is sealed.

[0025] The introduction pipe 170 is inserted into the case 240. The introduction pipe 170 and the insulating part 242 continuing from the case 240 are radially spaced apart to form a double pipe structure. Furthermore, the part between the first connecting part 331 and the second connecting part 332 in the external partition member is radially spaced apart from the introduction pipe 170 and the insulating part 242 to form a double pipe structure. In addition, the introduction pipe 170, the insulating part 242 and the external partition member are radially spaced apart to form a triple pipe structure. As described above, the catalyst device 39 has a triple pipe structure and multiple double pipe structures in a part upstream of the catalyst carrier 19 in the exhaust direction. The triple pipe structure and multiple double pipe structures form a labyrinth part 340 into which the exhaust gas can flow. The labyrinth part 340 is connected to the exhaust passage 13 through a gap between the introduction pipe 170 and the insulating part 242.

[0026] <Regarding the control of the wastegate valve 25 performed by the processing device 31> The processing device 31 executes 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 executes the first control.

[0027] 2, the first control is a control in which the processing device 31 changes the opening degree of the wastegate valve 25 to an opening degree such that the inner circumferential surface 242A of the insulating part 242 is positioned on an extension line 410 of a seal surface 400 of the wastegate valve 25. The seal surface 400 is a surface that closes the outlet of the bypass passage 24 in the wastegate valve 25. The seal surface 400 of the wastegate valve 25 is a flat surface.

[0028] On the other hand, the second control is a control in which the processing device 31 changes the opening degree of the wastegate valve 25 according to a target boost pressure of the internal combustion engine 10. In the second control, the processing device 31 sets the target boost pressure according to the operating conditions of the internal combustion engine 10. Furthermore, the processing device 31 controls the opening degree of the wastegate valve 25 so that the boost pressure becomes the target boost pressure.

[0029] 3 shows the flow of a series of processes executed by the processing device 31. This series of processes is executed by the processing device 31 upon completion of starting of the internal combustion engine 10. This series of processes is repeatedly executed at every predetermined control period until the processing device 31 finishes executing the second control.

[0030] When this series of processes is started, the processing device 31 first determines in the process of step S100 whether or not the warm-up of the internal combustion engine 10 is completed. 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 acquired from the water temperature sensor 35 becomes equal to or higher than a predetermined value.

[0031] If the warm-up of the internal combustion engine 10 is not completed (step S100: NO), the process proceeds to step S110. In the process of step S110, the processing device 31 executes the first control. After executing the process of step S110, the processing device 31 temporarily ends this series of processes. Thereafter, the processing device 31 executes this series of processes again for each predetermined control period.

[0032] On the other hand, if the warm-up of the internal combustion engine 10 is complete (step S100: YES), the process proceeds to step S120. In the process of step S120, if the processing device 31 is not executing the first control, the processing device 31 starts the second control. In the process of step S120, if the processing device 31 is executing the first control, the processing device 31 ends the first control. Thereafter, the processing device 31 starts the second control. After executing the process of step S120, the processing device 31 ends this series of processes.

[0033] That is, the processing device 31 executes the first control until completion of the warm-up of the internal combustion engine 10. When the warm-up of the internal combustion engine 10 is completed, the processing device 31 ends the first control and executes the second control. <Operation of the First Embodiment> The processing device 31 of the control device 30 controls the opening of the wastegate valve 25 when the internal combustion engine 10 is started, so that the exhaust gas blown out from the outlet of the bypass passage 24 can be concentrated on the inner circumferential surface 242A of the insulating part 242, which is an internal partitioning member. As a result, the temperature of the insulating part 242 is more likely to rise than when the exhaust gas wiped out from the outlet of the bypass passage 24 is not concentrated on the inner circumferential surface 242A of the insulating part 242. As a result, the temperature difference between the insulating part 242 and the external partitioning member increases. The temperature gradient between the insulating part 242 and the external partitioning member increases due to the increase in the temperature difference between the insulating part 242 and the external partitioning member. When the temperature gradient increases, thermophoresis driven by the temperature gradient becomes active. As a result, the particulate matter PM is more likely to move from the vicinity of the insulating part 242, which is the high temperature side, to the external partitioning member, which is the low temperature side, due to thermophoresis. Therefore, the accumulation of the particulate matter PM in the insulating part 242 is suppressed.

[0034] <Advantages of the First Embodiment> (1) The control device 30 can maintain the insulation properties of the insulating portion 242 even when the temperature of the exhaust gas decreases as it passes through the bypass passage 24.

[0035] (2) The control device 30 executes a first control in which the processing device 31 controls the opening degree of the wastegate valve 25 to an opening degree such that the inner circumferential surface 242A of the insulating part 242 is located on the extension line 410 of the seal surface 400 of the wastegate valve 25. In addition, the control device 30 executes a second control in which the processing device 31 controls the opening degree of the wastegate valve 25 according to the target boost pressure of the internal combustion engine 10. By the time the warm-up of the internal combustion engine 10 is completed, the combustion is stable and the amount of particulate matter PM contained in the exhaust gas is reduced. The temperature of the exhaust gas that has passed through the bypass passage 24 is also high. 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 executes the second control. This allows the control device 30 to shift the control of the wastegate valve 25 from the first control to the second control at an appropriate timing. Furthermore, the control device 30 can execute a normal boost pressure control to achieve the target boost pressure in the second control.

[0036] <Modification of the first embodiment> This embodiment can be modified as follows: This embodiment and the following modifications can be combined with each other to the extent that there is no technical contradiction.

[0037] When determining whether the warm-up of the internal combustion engine 10 is completed, the processing device 31 of the control device 30 may determine that the warm-up is completed if the lubricant 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 lubricant temperature from a lubricant temperature sensor.

[0038] When determining whether the warm-up of the internal combustion engine 10 is completed, the processing device 31 may determine that the warm-up is completed when the integrated intake air flow rate from the start of operation becomes equal to or greater than a preset value. The processing device 31 may calculate the integrated intake air flow rate from the intake air flow rate obtained from the air flow meter 33.

[0039] When determining whether the warm-up of the internal combustion engine 10 is complete, the processing device 31 may correct a default value of the integrated intake air flow rate at which it is determined that the warm-up of the internal combustion engine 10 is complete, 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 default value of the integrated intake air flow rate at which it is determined that the warm-up of the internal combustion engine 10 is complete, to a higher value.

[0040] Second embodiment Next, a second embodiment will be described with reference to Fig. 4. The second embodiment will be described mainly with respect to 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.

[0041] 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. 4 shows the flow of a series of processes executed by the processing device 31 in the second embodiment. This series of processes is executed by the processing device 31 upon completion of starting of the internal combustion engine 10. This series of processes is repeatedly executed at every predetermined control period until the processing device 31 finishes executing the first control.

[0042] When starting this series of processes, the processor 31 first determines in the process of step S200 whether the first control has continued for a predetermined time or longer. If the first control has not continued for the predetermined time or more (step S200: NO), the process proceeds to step S210. In the process of step S210, the processing device 31 estimates whether the temperature of the insulating unit 242 is equal to or higher than the predetermined temperature. For example, when the amount of heat received by the insulating unit 242 from the exhaust gas becomes equal to or higher than a predetermined value, the processing device 31 may estimate that the insulating unit 242 is equal to or higher than the predetermined temperature. The amount of heat received by the insulating unit 242 from the exhaust gas correlates with the flow rate of the exhaust gas hitting the insulating unit 242. The flow rate of the exhaust gas correlates with the intake flow rate. Therefore, the processing device 31 determines whether the amount of heat received by the insulating unit 242 from the exhaust gas is equal to or higher than the predetermined value based on the integrated intake flow rate calculated from the intake flow rate obtained from the air flow meter 33.

[0043] If it is estimated that the temperature of the insulating section 242 is equal to or higher than the predetermined temperature (step S210: YES), the process proceeds to step S230. In the process of step S230, the processing device 31 ends the first control. Thereafter, the processing device 31 starts the second control. After executing the process of step S230, the processing device 31 ends this series of processes. If it is estimated that the temperature of the insulating section 242 is lower than the predetermined temperature (step S210: NO), the process proceeds to step S220. In the process of step S220, the processing device 31 executes the first control. After executing the process of step S220, the processing device 31 temporarily ends this series of processes. Thereafter, the processing device 31 executes this series of processes again for each predetermined control period.

[0044] On the other hand, if the first control has continued for the predetermined time or longer (step S200: YES), the process proceeds to step S230. In the process of step S230, the processing device 31 ends the first control. Thereafter, the processing device 31 starts the second control. After executing the process of step S230, the processing device 31 ends this series of processes.

[0045] <Operation of the Second Embodiment> It is believed that if the temperature of the insulating portion 242 becomes sufficiently high, the temperature gradient between the insulating portion 242 and the external partition member can be maintained large enough to cause thermophoresis of the particulate matter PM, even if the first control is terminated.

[0046] Therefore, the processing device 31 of the control device 30 ends the first control on the condition that the temperature of the insulating part 242 is equal to or higher than the predetermined temperature. Subsequently, the processing device 31 performs the second control. <Effects of the second embodiment> (1) The control device 30 can control the internal combustion engine 10 so as to satisfy the target boost pressure of the internal combustion engine 10 while maintaining the insulation properties of the insulating portion 242.

[0047] (2) When the first control continues for a predetermined time or more, the control device 30 ends the first control. Thereafter, the processing device 31 starts the second control. When the first control continues for a predetermined time or more, it is considered that the temperature gradient between the insulating portion 242 and the external partition member can be maintained large enough to cause thermophoresis of the particulate matter PM. Therefore, the processing device 31 ends the first control on the condition that the first control has been continuously performed for a predetermined time or more. Then, the processing device 31 performs the second control. This allows the control device 30 to control the internal combustion engine 10 to satisfy the target boost pressure of the internal combustion engine 10 while maintaining the insulation of the insulating portion 242.

[0048] <Modification of the second embodiment> The second embodiment described above can be modified as follows: This embodiment and the following modifications can be combined with each other to the extent that no technical contradiction occurs.

[0049] By the time the warm-up of the internal combustion engine 10 is complete, combustion has stabilized and the amount of particulate matter PM contained in the exhaust gas has decreased. The temperature of the exhaust gas that has passed through the bypass passage 24 has also increased. Therefore, the processing device 31 of the control device 30 may set the length of time for determining in the processing of step S200 that the first control has continued for a predetermined time or more to a length of time that allows it to be determined that the warm-up of the internal combustion engine 10 has been completed. This allows the processing device 31 to transition the control of the wastegate valve 25 from the first control to the second control at an appropriate timing.

[0050] The processor 31 may omit the process of step S210. That is, the processor 31 may continue the first control (step S220) only on the condition that the duration of the first control is less than the predetermined time (step S200: NO).

[0051] The processing device 31 may use information other than the integrated intake air flow rate to estimate whether the temperature of the insulating part 242 is equal to or higher than a predetermined temperature. For example, when the detection value of the exhaust temperature sensor 18 is equal to or higher than a certain temperature, the processing device 31 may estimate that the temperature of the insulating part 242 is equal to or higher than a predetermined temperature.

[0052] The processing device 31 may omit the process of step S200. That is, the processing device 31 may end the first control only on the condition that the temperature of the insulating section 242 is equal to or higher than the predetermined temperature (step S210: YES). When the first control ends, the processing device 31 starts the second control (step S230). Furthermore, the processing device 31 may continue to execute the first control (step S220) only on the condition that the temperature of the insulating section 242 is lower than the predetermined temperature (step S210: NO).

[0053] The processing device 31 may control the wastegate valve 25 even after the transition to the second control to cause the exhaust air passing through the bypass passage 24 to hit the inner circumferential surface 242A of the insulating part 242. For example, as shown in FIG. 5, when the temperature of the insulating part 242 becomes lower than the lower limit temperature, the processing device 31 may control the opening degree of the wastegate valve 25 to cause the exhaust air to hit the inner circumferential surface 242A of the insulating part 242.

[0054] 5 shows the flow of a series of processes executed when the processing device 31 is performing the second control. When starting this series of processes, the processing device 31 first determines in step S300 whether the temperature of the insulating part 242 is below a lower limit temperature.

[0055] If the temperature of insulating section 242 is below the lower limit temperature (step S300: YES), the process proceeds to step S310. If the temperature of insulating section 242 is equal to or higher than the lower limit temperature (step S300: NO), the process of steps S310 to S330 is not executed, and the current process ends.

[0056] In the process of step S310, the processing device 31 ends the second control. After that, the processing device 31 starts the first control. Then, the process proceeds to step S320. In the process of step S320, the processing device 31 determines whether or not the end condition of the first control is satisfied. For example, if it is estimated that the temperature of the insulating part 242 is equal to or higher than a predetermined temperature, the processing device determines that the end condition of the first control is satisfied. For example, if the first control has continued for a predetermined time or longer, the processing device 31 determines that the end condition of the first control is satisfied.

[0057] If the end condition of the first control is satisfied (step S320: YES), the process proceeds to step S330. In the process of step S330, the processor 31 ends the first control. After that, the processor 31 resumes the second control. After executing the process of step S230, the processor 31 ends this series of processes.

[0058] When the end condition of the first control is not satisfied (step S320: NO), the processor 31 repeatedly executes the process of step S320 for each predetermined control period. While the processing device 31 is performing the second control, the flow of exhaust gas blown out from the outlet of the bypass passage 24 is not concentrated on the inner circumferential surface 242A of the insulating part 242. Therefore, while the processing device 31 is performing the second control, the temperature of the insulating part 242 may decrease. The processing device 31 may end the second control on the condition that the temperature of the insulating part 242 is estimated to be below the lower limit temperature. When the second control is ended, the processing device 31 performs the first control. This allows the processing device 31 to maintain the temperature of the insulating part 242 at a temperature at which the effect of thermophoresis is exerted.

[0059] <Other changes> Other elements that can be modified in common to the above-described embodiments include the following: The following modification examples can be implemented in combination with each other to the extent that there is no technical contradiction.

[0060] The vehicle to which the control device 30 is applied is not limited to a vehicle in which the thrust generating device is the internal combustion engine 10 alone. For example, the vehicle may be a series-parallel hybrid vehicle. For example, the vehicle may be a parallel hybrid vehicle. For example, the vehicle may be a series hybrid vehicle.

[0061] The control device 30 may be applied to an internal combustion engine 10 including a catalytic converter 39 that does not have a triple-pipe structure. For example, the control device 30 may be applied to an internal combustion engine 10 including a catalytic converter 39 in which the introduction pipe 170 is not disposed inside the case 240.

[0062] 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 idling stop process is executed and the internal combustion engine 10 is stopped, the control device 30 may start the first control when the idling stop process ends and the internal combustion engine 10 is restarted. For example, after a hybrid vehicle stops the internal combustion engine 10, the control device 30 may start the first control when the internal combustion engine 10 is restarted depending on the vehicle situation. [Explanation of symbols]

[0063] 10...internal combustion engine, 11...combustion chamber, 12...intake passage, 13...exhaust passage, 14...injector, 15...ignition device, 16...throttle valve, 17...crankshaft, 18...exhaust temperature sensor, 19...catalyst carrier, 20...turbocharger, 21...compressor wheel, 22...turbine wheel, 23...turbine shaft, 24...bypass passage, 25...wastegate valve, 30...control device, 31...processing device, 32...storage device, 33...air flow meter, 34...intake air temperature sensor, 35...water temperature sensor, 36...crank angle sensor, 7... supercharging pressure sensor, 38... intake manifold pressure sensor, 39... catalytic converter, 121... scroll passage, 122... accommodation space, 123... exhaust outlet, 170... inlet pipe, 210... upstream end of catalyst, 220... electrode, 221... electrode insertion hole, 222... electrode holder, 230... mat, 240... case, 241... end, 242... insulating part, 242A... inner circumferential surface, 310... first connecting pipe, 320... second connecting pipe, 331... first connecting part, 332... second connecting part, 333... third connecting part, 340... labyrinth part, 400... sealing surface, 410... extension line, PM... particulate matter

Claims

1. a turbine wheel installed in an exhaust passage; a bypass passage branching off from the exhaust passage at a portion of the exhaust passage upstream of the turbine wheel and merging into the exhaust passage at a portion of the exhaust passage downstream of the turbine wheel; a catalytic device for exhaust purification installed in a portion of the exhaust passage downstream of the merging position; and a wastegate valve installed in the exhaust passage upstream of the catalytic device for closing an outlet of the bypass passage, the catalytic converter is an electrically heated catalytic converter provided in the exhaust passage and heated by passing current through the catalytic converter; A member that partitions the exhaust passage and guides exhaust gas to the catalyst includes an internal partitioning member that supports the catalyst inside in an electrically insulated state, and an external partitioning member that is connected to the internal partitioning member from the outside and covers an exhaust upstream end of the internal partitioning member from the outside in a radially spaced apart state, thereby forming a part of the outer shell of the exhaust passage, The present invention is applied to an internal combustion engine in which a portion of the inner partition member covered by the outer partition member is an insulating portion continuous with a portion supporting the catalyst, A control device for an internal combustion engine that controls the internal combustion engine, A processing device is provided, The processing device executes a first control for controlling an opening degree of the wastegate valve to an opening degree such that an inner circumferential surface of the insulating portion is positioned on an extension line of a sealing surface of the wastegate valve when the internal combustion engine is started. A control device for an internal combustion engine.

2. The processing device terminates the first control when the warm-up of the internal combustion engine is completed, A second control is started to control an opening degree of the wastegate valve in accordance with a target boost pressure of the internal combustion engine. The control device for an internal combustion engine according to claim 1.

3. When the temperature of the insulating portion is estimated to be equal to or higher than a predetermined temperature, the processing device ends the first control and starts a second control that controls an opening degree of the wastegate valve in accordance with a target boost pressure of the internal combustion engine. The control device for an internal combustion engine according to claim 1.

4. When the first control continues for a predetermined time or more, the first control is terminated, and a second control is started in which an opening degree of the wastegate valve is controlled in accordance with a target boost pressure of the internal combustion engine. The control device for an internal combustion engine according to claim 1.

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

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