Internal combustion engine system

Abstract

To prevent pump up when an exhaust switch valve has abnormality.SOLUTION: An internal combustion engine system comprises: an exhaust switch valve which is installed on an exhaust pipe of an internal combustion engine and changes an opening according to an air intake amount; and a control section which determines whether the exhaust switch valve has abnormality and executes air intake amount limiting control to limit the air intake amount when determining that the exhaust switch valve has abnormality. The control section determines that the exhaust switch valve has abnormality when a state where the opening of the exhaust switch valve is too large for the air intake amount lasts for a predetermined period. The control section also determines that the exhaust switch valve has abnormality when a valve opening sensor does not detect the opening that corresponds to an indicated value of the opening for the exhaust switch valve.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to internal combustion engine systems. [Background technology]

[0002] Conventionally, there is known a technique for controlling an internal combustion engine based on the difference between a reference back pressure calculated from the intake air amount detected by an air flow meter and an actual back pressure detected by an exhaust pressure sensor (see, for example, Patent Document 1). Here, the back pressure is the pressure inside the exhaust pipe. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 11-190235 Summary of the Invention [Problem to be solved by the invention]

[0004] Recently, internal combustion engines equipped with an exhaust gas changeover valve have become known. The exhaust gas changeover valve opens when the internal combustion engine is operating at high speeds, allowing the exhaust gas to escape more easily, making it easier to obtain power and producing a distinctive exhaust sound. On the other hand, the exhaust gas changeover valve closes when the vehicle is traveling at low speeds, such as in urban areas, to ensure quietness during the vehicle's travel.

[0005] However, if an abnormality occurs in such an exhaust switching valve, such as a valve position sensor that detects the valve position or the valve disc sticking closed, back pressure will increase. In particular, if an abnormality occurs in the exhaust switching valve and back pressure increases when the internal combustion engine is operating at high speed and under high load, pump-up may occur. Pump-up is a phenomenon in which the exhaust valve, which is located upstream of the exhaust pipe and opens and closes the combustion chamber, becomes difficult to close. When pump-up occurs, compression within the cylinder of the internal combustion engine is insufficient, combustion conditions deteriorate, reducing the performance of the internal combustion engine, and valve seals may be exposed to high combustion heat and become more susceptible to deterioration.

[0006] Therefore, an object of the invention disclosed in this specification is to suppress the occurrence of pump-up when an abnormality occurs in the exhaust gas switching valve. [Means for solving the problem]

[0007] The above object can be achieved by an internal combustion engine system that includes an exhaust switching valve that is provided in an exhaust pipe and whose opening degree changes depending on the amount of intake air, and a control unit that determines whether the exhaust switching valve is abnormal or not, and if it determines that the exhaust switching valve is abnormal, performs intake air amount restriction control that restricts the amount of intake air using a throttle valve.

[0008] In the above configuration, the control unit may be configured to make an abnormality determination that the exhaust switching valve is abnormal when it determines that the opening of the exhaust switching valve has been too closed compared to the intake air volume for a predetermined period of time.

[0009] Furthermore, in the above configuration, the exhaust switching valve may include a valve opening sensor that detects the opening of the valve body, and the control unit may make an abnormality determination that the exhaust switching valve is abnormal when the valve opening sensor does not detect an opening that corresponds to an instruction value for the opening of the exhaust switching valve.

[0010] Furthermore, in the above configuration, the control unit can be configured to determine whether the exhaust switching valve is abnormal and avoid the intake air amount restriction control when it determines that the warm-up of the exhaust switching valve has not been completed.

[0011] Furthermore, in the above configuration, when a vehicle diagnostic device is connected to the internal combustion engine and the vehicle diagnostic device issues an opening instruction other than a fully open instruction for the exhaust switching valve, the control unit may be configured to determine whether the exhaust switching valve is abnormal and to avoid the intake air amount restriction control. [Effects of the Invention]

[0012] The invention disclosed in this specification can suppress the occurrence of pump-up when an abnormality occurs in the exhaust gas switching valve. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a schematic diagram showing a schematic configuration of an internal combustion engine according to an embodiment. [Figure 2] FIG. 2 is a schematic diagram showing a schematic configuration of the exhaust gas switching valve according to the embodiment. [Figure 3] FIG. 3 is a flowchart showing an example of control of the internal combustion engine according to the embodiment. [Figure 4] Figure 4(A) is a diagram showing the exhaust switching valve stuck in a closed state, Figure 4(B) is a diagram showing the exhaust switching valve stuck in a medium opening state, and Figure 4(C) is a diagram showing the exhaust switching valve over-opened. [Figure 5] FIG. 5 is an example of a map for setting a determination opening degree of the exhaust gas changeover valve that avoids pump-up in the internal combustion engine of the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. However, the dimensions and proportions of the various parts in the drawings may not be exactly the same as those in reality. In addition, some details may be omitted in the drawings.

[0015] (Embodiment) [Configuration of internal combustion engine system] First, a schematic configuration of an internal combustion engine system 100 according to an embodiment will be described with reference to Fig. 1. The internal combustion engine system 100 includes an internal combustion engine 1 that uses gasoline as fuel to obtain rotational driving force, a silencer 30, a first muffler 31, a second muffler 32, and a third muffler 33. The internal combustion engine system 100 further includes an ECU (Electronic Control Unit) 40 that corresponds to a control unit. The internal combustion engine 1 can use conventionally known gasoline alternative fuels such as ethanol and natural gas instead of gasoline. The internal combustion engine may also be a diesel engine.

[0016] The internal combustion engine 1 has a plurality of cylinders 2 in a cylinder block (only one cylinder 2 is shown in FIG. 1 ). A piston 3 is slidably housed in each cylinder 2, and a combustion chamber 2a is formed between the piston 3 and a cylinder head disposed above the cylinder block. The piston 3 is connected to a crankshaft 5 via a connecting rod 4. An injector 6 that injects fuel into the cylinder and a spark plug 7 are provided in the combustion chamber 2a. The fuel injected from the injector 6 becomes an air-fuel mixture in the combustion chamber 2a and is ignited by the spark plug 7. The ignited air-fuel mixture burns and explodes, pushing the piston 3 downward. The pushed-down piston 3 transmits the explosive force to the crankshaft 5 via the connecting rod 4, causing the crankshaft 5 to rotate. The injector 6 may be provided in an intake pipe 10 near the combustion chamber 2a.

[0017] The internal combustion engine 1 is provided with an intake port 8 and an exhaust port 9 facing the combustion chamber 2a, with an intake pipe 10 connected to the intake port 8 and an exhaust pipe 11 connected to the exhaust port 9.

[0018] The intake pipe 10 is provided with an air cleaner 12, an air flow meter 13, a throttle valve 17, and an intake manifold 18, in that order from the upstream side of the intake air flow. The throttle valve 17 is provided with a throttle opening sensor 17a. The air flow meter 13 detects the amount of air flowing through the intake pipe 10, i.e., the intake air amount GA. The throttle valve 17 adjusts the amount of air sent into the combustion chamber 2a. The throttle opening sensor 17a detects the opening of the throttle valve 17. The intake pipe 10 branches at the intake manifold 18 and is connected to the intake ports 8 of each cylinder.

[0019] An exhaust manifold 20 and a catalyst 21 are provided in the exhaust pipe 11, in that order from the upstream side of the exhaust flow. The catalyst 21 purifies the exhaust. A silencer 30 is provided at the end of the exhaust pipe 11. The exhaust pipe 11 branches into a first muffler 31, a second muffler 32, and a third muffler 33 inside the muffler 30. The first muffler 31 and the second muffler 32 branch to the left and right along the longitudinal direction of the muffler 30. The third muffler 33 extends between the first muffler 31 and the second muffler 32.

[0020] The third muffler 33 is provided with an exhaust gas switching valve 34. The exhaust gas switching valve 34 is provided with a valve opening sensor 35 that detects the opening degree of the exhaust gas switching valve 34.

[0021] Here, the schematic configuration of the exhaust gas switching valve 34 will be described with reference to Fig. 2. The exhaust gas switching valve 34 includes a housing 34a having an opening 34a1, and a valve element 34b rotatably provided so as to open and close the opening 34a1. The opening direction of the valve element 34b is clockwise, and the closing direction of the valve element 34b is counterclockwise. The valve opening sensor 35 shown in Fig. 1 detects the rotation angle of the valve element 34b as the opening degree of the valve element 34b.

[0022] The internal combustion engine 1 is equipped with an intake valve 23 that opens and closes the intake port 8, and an exhaust valve 24 that opens and closes the exhaust port 9. The intake valve 23 is slidably mounted relative to a valve guide 23a. The valve guide 23a is provided with a valve seal 23b. The exhaust valve 24 is slidably mounted relative to a valve guide 24a. The valve guide 24a is provided with a valve seal 24b. The intake valve 23 and the exhaust valve 24 open and close in accordance with the rotation of an intake camshaft and an exhaust camshaft (not shown) that are drivingly connected to the crankshaft 5. As a result, the intake valve 23 and the exhaust valve 24 are driven to open and close at predetermined timings corresponding to the reciprocating movement of each piston 3 in synchronization with the rotation of the crankshaft 5. The internal combustion engine 1 is equipped with an intake VVT ​​mechanism 25, which is a variable valve mechanism that variably sets the valve timing, which is the timing at which the intake valve 23 opens and closes, and an exhaust VVT mechanism 26, which is a variable valve mechanism that variably sets the valve timing, which is the timing at which the exhaust valve 24 opens and closes. The intake VVT ​​mechanism 25 and the exhaust VVT mechanism 26 form a variable valve timing device.

[0023] The internal combustion engine 1 includes a water jacket (not shown) through which cooling water circulates, and a water temperature sensor 71 that detects the temperature of the cooling water circulating in the water jacket.

[0024] The ECU 40 includes a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), and a storage device. The ECU 40 controls the internal combustion engine system 100 by executing programs stored in the ROM and the storage device. The ECU 40 is electrically connected to the air flow meter 13, the throttle opening sensor 17a, the valve opening sensor 35, and the water temperature sensor 71, and receives signals from these sensors. The ECU 40 is also electrically connected to the throttle valve 17, the intake VVT ​​mechanism 25, the exhaust VVT mechanism 26, and the exhaust switching valve 34, and transmits signals thereto to control their operation. The ECU 40 also has a timekeeping function. In addition to these, various sensors for controlling the internal combustion engine system 100 are electrically connected to the ECU 40, but detailed description of these sensors will be omitted here.

[0025] A vehicle diagnostic device 80 may be connected to the ECU 40, for example, in a repair shop or the like. The vehicle diagnostic device 80 can arbitrarily set the state of each part included in the internal combustion engine system 100 in order to check the state of the vehicle. The vehicle diagnostic device 80 can set the exhaust gas switching valve 34 to an arbitrary opening degree. In this case, the vehicle diagnostic device 80 can set the opening degree of the exhaust gas switching valve 34 separately from the intake air amount GA, that is, separately from the intake air amount GA.

[0026] In a normal state where the vehicle diagnostic device 80 is not connected, the ECU 40 controls the opening degree of the exhaust switching valve 34 based on the intake air amount GA detected by the air flow meter 13. The exhaust switching valve 34 is controlled so that its opening degree increases as the intake air amount GA increases. However, if the exhaust switching valve 34 is abnormal, the opening degree of the exhaust switching valve 34 is not guaranteed to correspond to the intake air amount GA, and in some cases, the exhaust valve 24 may not close properly, resulting in a so-called pump-up. Pump-up is thought to occur when the exhaust switching valve 34 is closed and the back pressure, which is the pressure in the exhaust pipe 11, increases. When pump-up occurs, compression within the cylinder is insufficient, which can deteriorate the combustion state in the combustion chamber 2a and cause the valve seal 24b to be exposed to high combustion heat and become susceptible to deterioration.

[0027] [Pump-up prevention control] In the following, control to avoid the occurrence of pump-up when it is determined that the exhaust switching valve 34 including the valve opening sensor 35 is abnormal will be described with reference to the flowchart shown in Fig. 3. The flowchart shown in Fig. 3 includes a determination as to whether or not the exhaust switching valve 34 is abnormal, and an intake air amount restriction control that is implemented when a state in which the exhaust switching valve 34 is determined to be abnormal continues for a predetermined period of time.

[0028] In step S1, the ECU 40 determines whether the internal combustion engine system 100 is being forcibly driven by the vehicle diagnosis device 80. When the vehicle diagnosis device 80 is connected to the ECU 40 and a vehicle diagnosis is being performed, the control by the vehicle diagnosis device 80 takes priority over the control of the internal combustion engine system 100 by the ECU 40. For example, assume that the vehicle diagnosis device 80 is connected to the internal combustion engine system 100 and the accelerator pedal of the vehicle is depressed. At this time, assume that the opening degree of the exhaust gas switching valve 34 determined by the vehicle diagnosis device 80 is an intermediate opening degree, such as 20 degrees, and that the opening degree of the exhaust gas switching valve 34 corresponding to the intake air amount GA due to accelerator depression is higher than the setting value set by the vehicle diagnosis device 80. In such a case, the valve opening degree sensor 35 detects the opening degree set by the vehicle diagnosis device 80, which may be inconsistent with the opening degree of the exhaust gas switching valve 34 corresponding to the intake air amount GA, resulting in an erroneous determination. Therefore, in such a case, in order to avoid erroneous determination, the ECU 40 does not, in principle, perform abnormality determination for the exhaust switching valve 34 including the valve opening sensor 35. When the ECU 40 makes a positive determination (Yes determination) in step S1, it proceeds to step S2, and when the ECU 40 makes a negative determination (No determination), it proceeds to step S3.

[0029] In step S2, the ECU 40 determines whether the vehicle diagnosis device 80 has issued a full-open command to the exhaust gas changeover valve 34. If the ECU 40 determines negative in step S2, it returns the process. If the ECU 40 determines positive in step S2, it proceeds to step S4. The determination in step S2 is performed because, if the vehicle diagnosis device 80 has set the exhaust gas changeover valve 34 to a fully open state, it is possible to perform abnormality detection while avoiding erroneous detection of the exhaust gas changeover valve 34. As will be described in detail later, a state in which the exhaust gas changeover valve 34 is determined to be abnormal is a state in which the actual valve opening degree A is smaller than the determined opening degree AZ (see step S9). This is because, when an abnormality occurs in which the exhaust gas changeover valve 34 is stuck in a closed state, back pressure increases, making it more likely that a pump-up will occur. If the vehicle diagnosis device 80 has issued a full-open command to the exhaust gas changeover valve 34 when the exhaust gas changeover valve 34 is stuck, it is considered that the exhaust gas changeover valve 34 is stuck in a state that is closer to the instructed opening degree. In other words, this coincides with the state that is being detected in this embodiment. In such a case, the control proceeds to step S4 and subsequent steps.

[0030] In step S3, the ECU 40 determines whether the engine water temperature T is equal to or higher than a reference water temperature TZ. For example, if the vehicle is placed in a low-temperature environment and the exhaust gas switching valve 34 is frozen, the ECU 40 may erroneously determine that an abnormality has occurred in the exhaust gas switching valve 34, even though the abnormality is not actually occurring in the exhaust gas switching valve 34. Therefore, if the ECU 40 determines that the engine water temperature T is lower than the reference water temperature TZ, that is, that the warm-up has not been completed, the ECU 40 avoids determining whether the exhaust gas switching valve 34 is abnormal and avoids the intake air amount restriction control (see step S7), which will be described later. The engine water temperature T is detected by a water temperature sensor 71. The reference water temperature TZ is a water temperature that is set in advance through simulation or actual engine testing as a value at which it can be determined that the internal combustion engine 1 is warming up and that the exhaust gas switching valve 34 is not frozen. In this embodiment, the warm-up determination is based on the water temperature. However, the warm-up determination may also be performed using other parameters that are correlated with the water temperature, such as oil temperature or other temperatures.

[0031] If the ECU 40 makes a negative determination in step S3, the ECU 40 returns the process. If the ECU 40 makes a positive determination in step S3, the ECU 40 proceeds to step S4.

[0032] In step S4, the ECU 40 determines whether the opening of the exhaust switching valve 34 detected by the valve opening sensor 35 is the opening commanded by the ECU 40. Step S4 is one of the abnormality determinations. This step is performed to determine whether an abnormality has occurred in the valve opening sensor 35. The ECU 40 issues an opening command for the exhaust switching valve 34 in accordance with the intake air amount GA. On the other hand, if the opening of the exhaust switching valve 34 detected by the valve opening sensor 35 differs from the opening commanded by the ECU 40, an abnormality is suspected in the valve opening sensor 35. If an abnormality has occurred in the valve opening sensor 35, the state of the exhaust switching valve 34 cannot be accurately determined. In this case, depending on the state of the exhaust switching valve 34, back pressure may increase, potentially causing a pump-up. Note that if the determination of step S4 is performed via step S2, the full-open command from the vehicle diagnosis device 80 is taken as the opening commanded by the ECU 40.

[0033] Here, an abnormality in the valve position sensor 35 is assumed to occur when the detected value is higher than the actual position. In this case, the ECU 40 attempts to control the exhaust switching valve 34 to close based on the detected value. As a result, the exhaust switching valve 34 is assumed to enter a state in which the valve body 34b closes the opening 34a1, as shown in FIG. 4A. In this case, back pressure increases, which may result in pump-up.

[0034] On the other hand, an abnormality in the valve position sensor 35 is assumed to occur when the detected value is lower than the actual position. In this case, the ECU 40 attempts to control the exhaust switching valve 34 to open based on the detected value. As a result, it is assumed that the exhaust switching valve 34 enters a state in which the valve body 34b closes the opening 34a1, as shown in FIG. 4C. In this case, back pressure increases, and there is a possibility that pump-up may occur.

[0035] However, even if such a situation is observed, pump-up does not occur immediately. In other words, if pump-up occurs, it takes time for the back pressure to actually increase, and it is possible that the determination that the valve position sensor 35 is abnormal will be resolved by the time the back pressure increases. Therefore, the ECU 40 determines whether a state in which the opening degree is not detected in accordance with the opening degree command has continued for a predetermined period of time by processing steps S5 and S6 described below.

[0036] If the ECU 40 makes a negative determination in step S4, the ECU 40 proceeds to step S5. Then, in step S5, the ECU 40 starts counting the duration H1. In step S6, the ECU 40 determines whether the duration H1 is equal to or longer than a determination time H1Z. The determination time H1Z is a period that is set in advance through simulation or actual machine adaptation as a period during which a pump-up is thought to occur due to a continuing abnormality in the exhaust gas switching valve 34.

[0037] If the ECU 40 makes a negative determination in step S6, the ECU 40 returns the process. If the ECU 40 makes a positive determination in step S6, the ECU 40 proceeds to step S7.

[0038] In step S7, the ECU 40 adjusts the opening of the throttle valve and restricts the amount of intake air. Pump-up is more likely to occur as the internal combustion engine 1 becomes higher in load and speed. Therefore, in step S7, the amount of intake air is restricted to avoid a situation where the internal combustion engine 1 becomes higher in load and speed, and to suppress an increase in back pressure. This prevents pump-up. By preventing pump-up, deterioration of the combustion state in the combustion chamber 2a is avoided, and the valve seal 24b is prevented from being easily deteriorated due to exposure to high-temperature combustion heat.

[0039] If the ECU 40 makes a positive determination in step S4, the process proceeds to step S8. In step S8, the ECU 40 resets the duration H1 and proceeds to step S9. In step S9, the ECU 40 determines a determination opening degree AZ of the exhaust switching valve 34 according to the intake air amount GA detected by the air flow meter 13. The ECU 40 determines the determination opening degree AZ based on the map shown in FIG. 5. The horizontal axis of the map shown in FIG. 5 represents the intake air amount GA, and the vertical axis represents the determination opening degree AZ. The determination opening degree AZ increases as the intake air amount GA increases. In the map shown in FIG. 5, the area below the hatched solid line is set as an area where pump-up may occur, and the area above the solid line is set as an area where there is no or low possibility of pump-up occurring.

[0040] In step S10, which follows step S9, the ECU 40 determines whether the valve opening A is smaller than the determination opening AZ. Step S10 is one of the abnormality determinations. Here, the valve opening A is a value detected by the valve opening sensor 35. As described above, since there is a possibility of pump-up in the hatched region in the map shown in FIG. 5, the comparison between the valve opening A and the determination opening AZ may be performed only when the hatched region is set within this region. When the region falls above the solid line in the map shown in FIG. 5, the process may be returned.

[0041] Here, the state of the exhaust gas switching valve 34 that is assumed when a positive determination is made in step S10 will be described. When a positive determination is made in step S10, it is assumed that the exhaust gas switching valve 34 is in a state where the valve element 34b is stuck in a closed position due to a malfunction of the actuator that drives the valve element 34b or the intrusion of foreign matter. For example, as shown in FIG. 4A, when the valve element 34b is stuck in a closed position, a positive determination is made in step S10. Furthermore, even when the valve element 34b is stuck at an intermediate opening, as shown in FIG. 4B, a positive determination may also be made in step S10 depending on the relationship with the intake air amount GA.

[0042] If the ECU 40 makes an affirmative determination in step S10, the ECU 40 proceeds to step S11, and if the ECU 40 makes a negative determination, the ECU 40 proceeds to step S12.

[0043] In step S11, the ECU 40 starts counting the duration H2 of the state for which a positive determination was made in step S10, and proceeds to step S13. Meanwhile, in step S12, the ECU 40 resets the duration H2, and proceeds to step S13. In step S13, the ECU 40 determines whether the duration H2 is equal to or greater than a determination time H2Z. The determination time H2Z is ​​a period that is set in advance through simulation or actual vehicle testing as a period during which a pump-up is expected to occur due to a continued abnormality in the exhaust switching valve 34. Note that the reason why the exhaust switching valve 34 is determined to be abnormal when it is determined that a state in which the exhaust switching valve 34 is excessively open relative to the intake air volume has continued for a predetermined period is as follows: Even if a state in which the exhaust switching valve 34 is excessively open does not immediately result in a pump-up, but rather it takes time for the back pressure to actually increase, and it is possible that the situation will improve before the back pressure increases. This is taken into consideration.

[0044] If the ECU 40 makes a negative determination in step S13, the ECU 40 returns the process. If the ECU 40 makes a positive determination in step S13, the ECU 40 proceeds to step S7.

[0045] In step S7, the ECU 40 restricts the intake air amount. Step S7 has already been described, so a detailed description thereof will be omitted here. After the processing of step S7 is performed, the processing returns.

[0046] According to the internal combustion engine system of this embodiment, when it is determined that the exhaust gas switching valve 34 is abnormal, intake air amount limiting control is performed to limit the amount of intake air, thereby avoiding pump-up.

[0047] The above-described embodiments are merely examples for implementing the present invention, and the present invention is not limited to these. Various modifications of these embodiments are within the scope of the present invention. Furthermore, it is obvious from the above description that various other embodiments are possible within the scope of the present invention. [Explanation of symbols]

[0048] 1 Internal combustion engine 8 Intake port 9 Exhaust port 10 Intake pipe 11 Exhaust pipe 18 Intake manifold 20 exhaust manifold 21 catalyst 23 Intake valve 24 Exhaust valve 25 Intake VVT ​​mechanism 26 Exhaust VVT mechanism 30 silencer 31 first muffler 32 Second muffler 33 Third muffler 34 Exhaust gas switching valve 35 Valve opening sensor 40 ECU 80 Vehicle diagnostic equipment 100 Internal combustion engine system

Claims

1. an exhaust switching valve provided in an exhaust pipe of the internal combustion engine, the opening degree of which is changed in accordance with the intake air amount; a control unit that determines whether the exhaust gas switching valve is abnormal, and when it is determined that the exhaust gas switching valve is abnormal, performs intake air amount restriction control that restricts the intake air amount by a throttle valve, When a vehicle diagnosis device is connected to the internal combustion engine and an opening instruction other than a full-open instruction for the exhaust switching valve is issued by the vehicle diagnosis device, the control unit avoids determining whether the exhaust switching valve is abnormal and performing the intake air amount restriction control, and when a full-open instruction for the exhaust switching valve is issued by the vehicle diagnosis device, the control unit determines whether the exhaust switching valve is abnormal and performs the intake air amount restriction control. Internal combustion engine system.

2. the control unit determines that the exhaust gas switching valve is abnormal when it determines that a state in which the opening degree of the exhaust gas switching valve is too closed relative to the intake air amount has continued for a predetermined period of time.

10. The internal combustion engine system of claim 1.

3. the exhaust gas switching valve includes a valve opening sensor that detects the opening of a valve element, the control unit determines that the exhaust gas switching valve is abnormal when the valve opening sensor does not detect an opening corresponding to an instruction value of the opening for the exhaust gas switching valve.

3. An internal combustion engine system according to claim 1 or 2.

4. When the control unit determines that the warm-up of the exhaust gas switching valve has not been completed, the control unit avoids determining whether the exhaust gas switching valve is abnormal and avoids the intake air amount restriction control.

10. The internal combustion engine system of claim 1.

Images