Control system for internal combustion engines

Abstract

This invention provides a control system for an internal combustion engine that can more efficiently raise the temperature of an exhaust gas purification device in an internal combustion engine where the exhaust gas purification device is located downstream of two superchargers. [Solution] The control system for an internal combustion engine includes a fuel injector that injects fuel into the cylinders, a first supercharger located in the exhaust passage, a second supercharger located downstream thereof, a bypass passage that bypasses the first supercharger and is connected to the upstream of the second supercharger, an exhaust purification device located downstream of the second supercharger that purifies the exhaust gas, a variable nozzle that changes the passage diameter of the turbine nozzle of the first supercharger, a wastegate valve that adjusts the exhaust gas flow rate to the turbine of the second supercharger, and a bypass valve located in the bypass passage that adjusts the amount of exhaust gas. The control device performs temperature rise control by controlling the variable nozzle to restrict the diameter of the turbine nozzle, controlling the bypass valve to open, and controlling the wastegate valve to open when raising the temperature of the exhaust purification device.

Description

Technical Field

[0001] The present disclosure relates to a control system for an internal combustion engine.

Background Art

[0002] Conventionally, a control system for an internal combustion engine having two superchargers in an exhaust passage is known (see, for example, Patent Document 1). The control system for the internal combustion engine of Patent Document 1 includes an exhaust purification device between a primary turbo and a secondary turbo. In the control system for the internal combustion engine of Patent Document 1, during the PM regeneration period, the nozzle opening of the variable nozzle of the secondary turbo is controlled to the valve closing side, and the nozzle opening of the variable nozzle of the primary turbo is controlled to the valve opening side. As a result, the internal pressure of the exhaust purification device rises without causing a decrease in the boost pressure, and the regeneration of PM is promoted.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The control system for the internal combustion engine of Patent Document 1 discloses control during the regeneration control of the exhaust purification device. Since the control system for the internal combustion engine of Patent Document 1 arranges the exhaust purification device between the primary turbo and the secondary turbo, it is possible to control to increase the internal pressure of the exhaust purification device during the regeneration control. On the other hand, when there is an exhaust purification device downstream of the secondary turbo, such control is difficult. In addition, the exhaust purification device requires temperature rise before executing the regeneration control.

[0005] An object of the present disclosure is to provide a control system for an internal combustion engine that can more efficiently execute the temperature rise of an exhaust purification device in an internal combustion engine having an exhaust purification device downstream of two superchargers.

Means for Solving the Problems

[0006] The control system for an internal combustion engine according to this disclosure comprises: a fuel injection device for injecting fuel into the cylinders of the internal combustion engine; a first supercharger having a turbine positioned in the exhaust passage of the internal combustion engine; a second supercharger having a turbine positioned downstream of the first supercharger; a bypass passage that bypasses the first supercharger and is connected to the upstream of the second supercharger; an exhaust purification device positioned downstream of the second supercharger for purifying the exhaust gas of the internal combustion engine; a variable nozzle positioned in the first supercharger for varying the passage diameter of the turbine nozzle of the first supercharger; a wastegate valve positioned in the second supercharger for adjusting the exhaust gas flow rate to the turbine of the second supercharger; a bypass valve positioned in the bypass passage for adjusting the amount of exhaust gas flowing through the bypass passage; and a control device for controlling the internal combustion engine, wherein the control device performs temperature-raising control by controlling the variable nozzle to restrict the diameter of the turbine nozzle, controlling the bypass valve to open, and controlling the wastegate valve to open when raising the temperature of the exhaust purification device. [Effects of the Invention]

[0007] According to this disclosure, exhaust gases pass through a bypass passage and head towards the second turbocharger. The exhaust gases that head towards the second turbocharger then pass through an open wastegate valve and flow to the exhaust gas purification device. As a result, the exhaust gases are supplied to the exhaust gas purification device without passing through the turbine. Therefore, the heat of the exhaust gases is not removed by the turbine before they flow to the exhaust gas purification device. As a result, the heating of the exhaust gas purification device can be performed efficiently. [Brief explanation of the drawing]

[0008] [Figure 1] A system diagram of a control system for an internal combustion engine according to one embodiment of the present disclosure. [Figure 2] A diagram showing the engine's injection pattern. [Figure 3] A flowchart illustrating a control procedure performed by a control device according to one embodiment of the present disclosure. [Modes for carrying out the invention]

[0009] Hereinafter, one embodiment of this disclosure will be described with reference to the drawings.

[0010] As shown in Figure 1, the control system 1 of the internal combustion engine 2 includes a fuel injector 4, a first supercharger 6, a second supercharger 8, a bypass passage 10, an exhaust gas purification device 12, a variable nozzle 14, a wastegate valve 16, a bypass valve 18, a throttle valve 20, an accelerator pedal (an example of an accelerator) 22, and a control device 24.

[0011] The internal combustion engine 2 of this embodiment is a four-cycle inline four-cylinder diesel engine in which four cylinders N are arranged in a row, and a fuel injection device 4 is installed in each cylinder N.

[0012] The fuel injector 4 is an in-cylinder injection device that directly injects fuel into cylinder N. The fuel injector 4 performs fuel injection to supply fuel to cylinder N. In this embodiment, the fuel injector 4 is connected to a fuel injection pump and an accumulator such as a common rail. The fuel injector 4 is electrically connected to a control device 24, which controls the injection amount (fuel injection amount) and the injection stage (number of fuel injections in one cycle). The diesel engine controls the output of the internal combustion engine 2 by the fuel injection amount. In other words, as the injection amount from the fuel injector 4 increases, the output of the internal combustion engine 2 increases.

[0013] As shown in Figure 2, in this embodiment, the fuel injector 4 injects a pilot injection PiI, a pre-injection PrI, a main injection MI, an after-injection AI, and a post-injection PI per cycle, with intake, compression, expansion, and exhaust being considered as one cycle.

[0014] The main injection MI is injected from the compression stroke to the expansion stroke. The main injection MI injects the majority of the fuel to be injected per cycle. The pilot injection PiI is injected before the main injection MI. The pilot injection PiI is injected in small amounts and can increase the combustion temperature inside the cylinder N, thereby reducing the ignition delay of the main injection MI. The pilot injection PiI can also suppress the rapid pressure increase of the main injection MI and reduce combustion noise. The pre-injection PrI is injected immediately before the main injection MI, i.e., between the pilot injection PiI and the main injection MI. The pre-injection PrI is injected in small amounts and can reduce combustion noise and nitrogen oxides. The after-injection AI is injected after the main injection MI. The after-injection AI can primarily burn any fuel that was not burned by the main injection MI. The post-injection PI is injected after the after-injection. The post-injection PI is performed, for example, to increase the temperature of the exhaust gas purification device 12.

[0015] In this embodiment, the internal combustion engine 2 is a two-stage turbo type internal combustion engine 2 having a first supercharger 6 and a second supercharger 8 connected in series. The first supercharger 6 is a turbocharger having a first compressor 6a and a first turbine 6b. The first compressor 6a and the first turbine 6b are arranged coaxially. The first compressor 6a is located in the intake passage 2b. The first turbine 6b is located in the exhaust passage 2a.

[0016] The second supercharger 8 is a turbocharger having a second compressor 8a and a second turbine 8b. The second compressor 8a and the second turbine 8b are arranged coaxially. The second compressor 8a is located upstream of the first compressor 6a in the intake passage 2b. The second turbine 8b is located downstream of the first turbine 6b (first supercharger 6) in the exhaust passage 2a.

[0017] The bypass passage 10 branches off from the exhaust passage 2a upstream of the first turbine 6b of the first supercharger 6, bypasses the first turbine 6b, and connects to the upstream of the second turbine 8b of the second supercharger 8.

[0018] The exhaust gas purification device 12 is disposed downstream of the second turbine 8b of the second supercharger 8 in the exhaust passage 2a and purifies the exhaust gas of the internal combustion engine 2. In the present embodiment, the exhaust gas purification device 12 is a diesel particulate filter that captures particulate matter in the exhaust gas. The exhaust gas purification device 12 has a temperature sensor 30. The temperature sensor 30 is electrically connected to the control device 24 and transmits the temperature T of the exhaust gas purification device 12 to the control device 24.

[0019] The variable nozzle 14 is disposed in the first turbine 6b of the first supercharger 6 and varies the passage diameter of the turbine nozzle of the first turbine 6b. That is, the first supercharger 6 is a variable vane type turbocharger. The variable nozzle 14 is controlled by a variable nozzle actuator 14a. The variable nozzle actuator 14a is electrically connected to the control device 24. The variable vane type turbocharger can rotate the first compressor 6a with a smaller exhaust gas flow rate by being controlled in the direction of closing (narrowing) the passage diameter of the turbine nozzle. In other words, the variable vane type turbocharger can perform supercharging in a lower rotational operation region by narrowing the passage diameter of the turbine nozzle. On the other hand, when the passage diameter of the turbine nozzle is narrowed, the exhaust gas resistance increases, which may result in exhaust gas energy loss.

[0020] The wastegate valve 16 is disposed on the second turbine 8b side of the second supercharger 8 and is a valve that adjusts the exhaust gas flow rate flowing into the second turbine 8b. Specifically, the second supercharger 8 has a wastegate passage 16a that bypasses the second turbine. The wastegate valve 16 adjusts the exhaust gas flow rate flowing into the second turbine 8b by opening and closing the wastegate passage 16a. The wastegate valve 16 is an electric or diaphragm type valve controlled by a wastegate actuator 16b. The wastegate actuator 16b is electrically connected to the control device 24.

[0021] The bypass valve 18 is disposed in the bypass passage 10 and adjusts the amount of exhaust flowing through the bypass passage 10. The bypass valve 18 of the present embodiment is an electric or diaphragm-type butterfly valve controlled by a bypass valve actuator 18a. The bypass valve actuator 18a is electrically connected to the control device 24.

[0022] The throttle valve 20 adjusts the amount of intake air flowing into the cylinder N by opening and closing the intake passage 2b of the internal combustion engine 2. The control system 1 of the internal combustion engine 2 of the present embodiment has an exhaust gas recirculation system 28. Since a diesel engine adjusts its output by the fuel injection amount, the throttle valve 20 is not normally used. However, when the exhaust gas recirculation system is operated and exhaust gas recirculation gas is introduced into the cylinder N, the throttle valve 20 is throttled to generate a negative pressure in the intake passage 2b, making it easier for the exhaust gas recirculation gas to be introduced. The throttle valve 20 is electrically connected to the control device 24, and its opening degree is controlled by the control device 24.

[0023] The accelerator pedal 22 is a device that instructs the output to the internal combustion engine 2. The accelerator pedal 22 of the present embodiment is depressed by the user of the vehicle on which the internal combustion engine 2 is mounted. The accelerator pedal 22 is electrically connected to the control device 24, and transmits the user's depression amount as the accelerator opening Th to the control device 24.

[0024] The control device 24 is a device that controls the internal combustion engine 2. The control device 24 is actually an ECU (Electronic Control Unit) composed of a microcomputer including an arithmetic unit, a memory, an input / output buffer, etc. The control device 24 controls the internal combustion engine 2 based on the maps and programs stored in the memory.

[0025] In this embodiment, the first turbocharger 6 can rotate with a lower exhaust flow rate than the second turbocharger 8. Specifically, the first turbine 6b has a smaller wheel diameter than the second turbine 8b. Therefore, the first turbocharger 6 is mainly used in low-speed or low-load operating ranges. On the other hand, the second turbocharger 8 is mainly used in medium-speed to high-speed operating ranges, or medium-load to high-load operating ranges.

[0026] When the exhaust gas purification device 12 does not require warm-up (hereinafter referred to as "normal conditions" in this specification), the control device 24 closes the bypass valve 18 in the low-speed or low-load operating range and supplies exhaust gas to the first turbine 6b. The first supercharger 6 rotates the first compressor 6a with the rotation of the first turbine 6b. The intake air supplied to the intake passage 2b passes through the second compressor 8a and is supplied to the first compressor 6a, where it is supercharged. The supercharged intake air passes through the intercooler 26, which cools the supercharged intake air, and is supplied to the cylinder N of the internal combustion engine 2.

[0027] The control device 24 opens the bypass valve 18 during normal operation, from the low-to-medium rotation range to the high rotation range, or from the medium-load range to the high-load range, bypassing the first turbine 6b and supplying exhaust to the second turbine 8b. The second supercharger 8 rotates the second compressor 8a in response to the rotation of the second turbine 8b. The intake air supplied to the intake passage 2b is supercharged by the second compressor 8a. The supercharged intake air passes through the intercooler 26, which cools the intake air, and is supplied to the cylinder N of the internal combustion engine 2.

[0028] The control device 24 calculates an instruction output (an example of an output) Q, which is an output to instruct the internal combustion engine 2 based on the accelerator opening Th. The accelerator opening Th is not limited to the actual opening of the accelerator pedal 22, but may be an opening indicated by a device such as a cruise control.

[0029] The control device 24 controls the variable nozzle 14 based on the instruction output Q. In this embodiment, the control device 24 stores the opening degree (passage diameter) of the variable nozzle 14, which is set according to the rotational speed and load (torque) of the internal combustion engine 2. The control device 24 acquires the load and rotational speed of the internal combustion engine 2, acquires the opening degree of the variable nozzle 14 according to the rotational speed and load (torque), and controls the variable nozzle 14.

[0030] The control device 24 controls the wastegate valve 16 based on the instruction output Q. Specifically, the control device 24 stores the opening degree of the wastegate valve 16, which is set according to the rotational speed and load (torque) of the internal combustion engine 2. The control device 24 obtains the load and rotational speed of the internal combustion engine 2, obtains the opening degree of the wastegate valve 16 according to the rotational speed and load (torque), and controls the wastegate valve 16.

[0031] Next, the control procedure performed by the control device 24 will be explained using the flowchart in Figure 3. In this specification, controlling the wastegate valve 16 or bypass valve 18 in the closing direction means not only completely closing the wastegate valve 16 or bypass valve 18, but also controlling it in the closing direction. Controlling the wastegate valve 16 or bypass valve 18 in the opening direction means not only completely opening the wastegate valve 16 or bypass valve 18, but also controlling it in the opening direction. Furthermore, controlling the variable nozzle 14 in the closing direction means controlling it in the direction that reduces the diameter of the turbine nozzle (throttling direction). Controlling the variable nozzle 14 in the opening direction means controlling it in the direction that increases the diameter of the turbine nozzle (opening direction).

[0032] In step S1, the control device 24 determines whether or not it is necessary to raise the temperature of the exhaust gas purification device 12. The control device 24 may, for example, obtain the temperature T of the exhaust gas purification device 12, and if the temperature T of the exhaust gas purification device 12 is less than the fourth predetermined temperature (for example, less than 500°C), it may determine that it is necessary to raise the temperature of the exhaust gas purification device 12. If the control device 24 determines that it is necessary to raise the temperature of the exhaust gas purification device 12 (step S1 YES), it proceeds to step S2.

[0033] In step S2, the control device 24 controls the variable nozzle 14 to narrow the diameter of the turbine nozzle (close the variable nozzle 14), controls the bypass valve 18 to open, and controls the wastegate valve 16 to open, thereby performing temperature rise control.

[0034] When the control device 24 performs temperature rise control, the exhaust gas passes through the bypass passage 10 and heads towards the second turbocharger 8. The exhaust gas that heads towards the second turbocharger 8 passes through the open wastegate valve 16 and flows to the exhaust gas purification device 12. As a result, the exhaust gas is supplied to the exhaust gas purification device 12 without passing through the first turbine 6b and the second turbine 8b (the amount of gas passing through is reduced). Therefore, the exhaust gas flows to the exhaust gas purification device 12 without losing heat to the first turbine 6b and the second turbine 8b (the amount of heat lost is reduced as much as possible). As a result, the temperature rise of the exhaust gas purification device 12 can be performed efficiently. When the control device 24 performs temperature rise control, it proceeds to step S3.

[0035] In step S3, the control device 24 determines whether the instruction output Q is less than a predetermined output Qt. If the control device 24 determines that the instruction output Q is less than a predetermined output Qt (step S3 YES), it proceeds to step S4.

[0036] In step S4, the control device 24 determines whether the temperature T is equal to or greater than the first predetermined temperature T1. The first predetermined temperature T1 is, for example, about half the temperature of the fourth predetermined temperature T4, which is the temperature at which warm-up is completed. If the control device 24 determines that the temperature T is equal to or greater than the first predetermined temperature T1 (step S4 YES), it proceeds to step S5. If the control device 24 determines that the temperature T is less than the first predetermined temperature T1 (step S4 NO), it proceeds to step S1.

[0037] In step S5, the control device 24 controls the bypass valve 18 to the closed direction. By controlling the bypass valve 18 to the closed direction in this way, the amount of exhaust gas flowing to the first turbine 6b of the first supercharger 6 increases. This increases the rotational speed of the first compressor 6a of the first supercharger 6. As a result, when the instruction output Q increases, the output of the internal combustion engine 2 increases rapidly. In other words, the response of the internal combustion engine 2 to the operation of the accelerator pedal 22 improves. When the control device 24 controls the bypass valve 18 to the closed direction, it completely closes the bypass valve 18 and performs normal control. When the control device 24 controls the bypass valve 18 to the closed direction, it proceeds to step S6.

[0038] In step S6, the control device 24 determines whether the temperature T is higher than or equal to the second predetermined temperature T2, which is higher than the first predetermined temperature T1. The second predetermined temperature is, for example, about two-thirds of the fourth predetermined temperature T4. If the control device 24 determines that the temperature T is higher than or equal to the second predetermined temperature (step S4 YES), it proceeds to step S7. If the control device 24 determines that the temperature T is lower than the second predetermined temperature (step S6 NO), it proceeds to step S1.

[0039] In step S7, the control device 24 controls the variable nozzle 14 in the open direction. By controlling the variable nozzle 14 in the open direction in this way, more exhaust gas flows into the first turbine 6b of the first supercharger 6, and the rotation of the first turbine 6b increases. As a result, the first compressor 6a of the first supercharger 6 rotates faster. Consequently, the output of the internal combustion engine 2 increases rapidly. In other words, the response of the internal combustion engine 2 to the operation of the accelerator pedal 22 improves. When the control device 24 controls the variable nozzle 14 in the open direction, it returns the variable nozzle 14 to its normal control state. When the control device 24 controls the variable nozzle 14 in the open direction, it proceeds to step S8.

[0040] In step S8, the control device 24 determines whether the temperature T is higher than or equal to the third predetermined temperature T3, which is higher than the second predetermined temperature T2. The third predetermined temperature T3 is, for example, about three-quarters of the temperature of the fourth predetermined temperature T4. If the control device 24 determines that the temperature T is higher than or equal to the third predetermined temperature T3 (step S8 YES), it proceeds to step S9. If the control device 24 determines that the temperature T is lower than the third predetermined temperature T3 (step S8 NO), it proceeds to step S1.

[0041] In step S9, the control device 24 performs normal state control, controlling the wastegate valve 16 based on an instruction output Q calculated based on the accelerator opening Th. This allows the control device 24 to quickly control the internal combustion engine 2 based on the accelerator opening Th. Once the control device 24 has returned the wastegate valve 16 to normal state control, it proceeds to step S10.

[0042] In step S10, the control device 24 determines whether the temperature T is higher than or equal to the fourth predetermined temperature T4, which is higher than the third predetermined temperature T3. The fourth predetermined temperature T4 is the temperature at which the exhaust gas purification device 12 is warmed up. If the control device 24 determines that the temperature T is higher than or equal to the fourth predetermined temperature T4 (step S10 YES), it proceeds to step S11. If the control device 24 determines that the temperature T is lower than the fourth predetermined temperature T4 (step S10 NO), it proceeds to step S1.

[0043] In step S11, the control device 24 performs regeneration control of the exhaust gas purification device 12. In this embodiment, the regeneration control is a control that burns and removes the soot accumulated on the diesel particulate filter. In the regeneration control, the control device 24 performs post-injection PI to raise the temperature of the exhaust gas purification device 12.

[0044] When the control device 24 performs post-injection PI during regeneration control, it restricts the throttle valve 20. This reduces the amount of air entering cylinder N, making the air-fuel ratio of cylinder N richer. As a result, the exhaust temperature rises. This makes it easier for the soot in the exhaust gas purification device 12 to burn, shortening the regeneration time of the exhaust gas purification device 12. The control device 24 returns after performing regeneration control. When regeneration control is completed (step S1 NO), the control device 24 opens the restricted throttle valve 20 and performs normal control.

[0045] If the control device 24 determines in step S1 that heating is not necessary, the control device 24 proceeds to step S12. In step S12, the control device 24 performs normal state control. After performing normal state control, the control device 24 returns.

[0046] If the control device 24 determines that the instruction output Q is equal to or greater than a predetermined output Qt (step S3 NO), it proceeds to step S14. In step S14, the control device 24 interrupts the temperature rise control, controls the diameter of the turbine nozzle to open (open to a larger degree) than the diameter based on the instruction output Q, controls the bypass valve 18 to close, and controls the wastegate valve to open (open to a larger degree) than the opening degree based on the instruction output Q.

[0047] When temperature rise control is performed, the first turbocharger 6 and the second turbocharger 8 are not overheated. Therefore, the first turbocharger 6 and the second turbocharger 8 can be used at higher rotational speeds (i.e., higher exhaust flow rates) than under normal conditions. For this reason, the control device 24 first uses the first turbocharger 6 at higher rotational speeds than under normal conditions. This increases the output of the internal combustion engine 2 by the first turbocharger 6 compared to under normal conditions. As a result, the timing of opening the bypass valve 18 and activating the second turbocharger 8 can be delayed. Therefore, the temperature of the exhaust purification device 12 can be increased while maintaining the output. The control device 24 returns after executing step S13.

[0048] As described above, this disclosure provides a control system for an internal combustion engine 2 that can more efficiently raise the temperature of the exhaust gas purification device 12 in an internal combustion engine 2 having an exhaust gas purification device 12 downstream of two superchargers.

[0049] <Other Embodiments> Although embodiments of the present disclosure have been described above, the present disclosure is not limited to the embodiments described above, and various modifications are possible without departing from the spirit of the invention. In particular, the various modifications described herein can be combined as needed.

[0050] In the above embodiment, an injection configuration in which pilot injection PiI, pre-injection PrI, main injection MI, after-injection AI, and post-injection PI are injected per cycle was described as an example, but this disclosure is not limited thereto. The fuel injection device 4 may have any injection configuration as long as it can perform post-injection PI. [Explanation of Symbols]

[0051] 1: Control System 2: Internal combustion engine, 2a: Exhaust passage, 2b: Intake passage 4: Fuel injection system, 6: First supercharger, 8: Second supercharger 10: Bypass passage, 12: Exhaust purification device, 14: Variable nozzle 16: Wastegate valve, 18: Bypass valve 20: Throttle valve, 24: Control device PI: Post-injection, Qt: Predetermined output T: temperature, T1: first predetermined temperature, T2: second predetermined temperature T3: 3rd predetermined temperature, T4: 4th predetermined temperature

Claims

1. A fuel injection system that injects fuel into the cylinders of an internal combustion engine, A first supercharger in which a turbine is positioned in the exhaust passage of the internal combustion engine, A second supercharger is provided, in which a turbine is positioned downstream of the first supercharger. A bypass passage that bypasses the first turbocharger and is connected to the upstream of the second turbocharger, An exhaust gas purification device is located downstream of the second supercharger and purifies the exhaust gas of the internal combustion engine, A variable nozzle is provided in the first supercharger and is used to vary the passage diameter of the turbine nozzle of the first supercharger, A wastegate valve is positioned in the second supercharger and adjusts the exhaust flow rate to the turbine of the second supercharger, A bypass valve is provided in the bypass passage for adjusting the amount of exhaust gas flowing through the bypass passage. A control device for controlling the internal combustion engine, Equipped with, The control device performs a temperature-raising control that, when raising the temperature of the exhaust gas purification device, controls the variable nozzle to restrict the diameter of the turbine nozzle, controls the bypass valve to open, and controls the wastegate valve to open. Control system for internal combustion engines.

2. The control device acquires the temperature of the exhaust gas purification device, and when the temperature reaches or exceeds a first predetermined temperature, controls the bypass valve to close. The control system for an internal combustion engine according to claim 1.

3. The control device acquires the temperature of the exhaust gas purification device, and when the temperature becomes higher than the first predetermined temperature, it controls the variable nozzle to open the turbine nozzle. The control system for an internal combustion engine according to claim 2.

4. The engine further comprises an accelerator for instructing the internal combustion engine to output power, When the temperature rises to or above a third predetermined temperature, which is higher than the second predetermined temperature, the control device controls the opening degree of the wastegate valve based on an output calculated based on the opening degree of the accelerator. The control system for an internal combustion engine according to claim 3.

5. When the temperature reaches a fourth predetermined temperature or higher, which is higher than the third predetermined temperature, the control device performs regeneration control to inject post-injection from the fuel injector. The control system for an internal combustion engine according to claim 4.

6. The engine further comprises a throttle valve that restricts the intake air flowing into the cylinder of the internal combustion engine, The control device controls the throttle valve in the closing direction when performing the post-injection. The control system for an internal combustion engine according to claim 5.

7. The engine further comprises an accelerator that controls the output of the internal combustion engine, If the output calculated based on the accelerator opening during the temperature rise control is greater than or equal to a predetermined output, the control device interrupts the temperature rise control, controls the diameter of the turbine nozzle to open it more than the diameter based on the output, controls the bypass valve to close it, and controls the wastegate valve to open it more than the opening degree based on the output. A control system for an internal combustion engine according to any one of claims 1 to 6.

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