JP2020186670A - Internal combustion engine system - Google Patents

Abstract

To provide a control device for an internal combustion engine capable of determining an abnormality of an exhaust changeover valve (opening fixation of the exhaust changeover valve) in a single turbo mode in an internal combustion engine system including a first supercharger and a second supercharger and having operation modes which are the single turbo mode of operating only the first supercharger and a twin turbo mode of operating the first supercharger and the second supercharger.SOLUTION: An internal combustion engine system includes a first supercharger, a second supercharger, an upstream side exhaust passage, an exhaust changeover valve, a first downstream side intake passage, a second downstream side intake passage, an intake changeover valve, an intake bypass passage, an intake bypass valve and compressor intake temperature detection means. A control device for an internal combustion engine controls the internal combustion engine. The control device enables switching between a single turbo mode, a twin turbo mode and a 1/2 switching mode on the basis of an operating state of the internal combustion engine. In the single turbo mode, the control device determines that an abnormality occurs in the exhaust changeover valve when a compressor intake temperature exceeds a predetermined threshold value.SELECTED DRAWING: Figure 1

Description

The present invention relates to an internal combustion engine system.

Conventionally, there is an internal combustion engine system in which two superchargers are provided in an intake system and an exhaust system in an internal combustion engine. In this internal combustion engine system, a primary turbocharger (corresponding to the first supercharger), which is a first supercharger that mainly operates as two superchargers, and a secondary turbocharger, which is a second supercharger. A turbocharger (corresponding to the second turbocharger) is arranged.

This internal combustion engine system has an operation mode in which the primary turbocharger is operated according to the operating state (hereinafter referred to as "single turbo mode") and an operation mode in which the primary turbocharger and the secondary turbocharger are operated. (Hereinafter referred to as "twin turbo mode") and.

For example, Patent Document 1 describes a first supercharger (corresponding to a first supercharger), a second supercharger (corresponding to a second supercharger), an exhaust passage, an intake passage, an exhaust switching valve, and an intake air. A control device for an internal combustion engine including a switching valve and a control means (corresponding to a control device) is disclosed. The exhaust passage communicates the turbine of the first supercharger and the turbine of the second supercharger, and the intake passage communicates the compressor of the first supercharger and the compressor of the second supercharger. The exhaust switching valve switches between a state in which exhaust flows to both the first supercharger and the first supercharger and the second supercharger, and the intake switching valve receives intake air from only the first supercharger. The state of being supplied and the state of being supplied with intake air from both the first supercharger and the second supercharger are switched.

In the internal combustion engine control device of Patent Document 1, each of the exhaust switching valve and the intake switching valve is opened in the twin turbo mode so that the exhaust switching valve and the intake switching valve are closed in the single turbo mode. To control. At this time, when switching to the twin turbo mode, the timing of starting the opening of the intake switching valve is delayed from the timing of starting the opening of the exhaust switching valve, thereby suppressing the drop in boost pressure that occurs at the time of switching.

JP-A-2010-209870

In the control device for an internal combustion engine described in Patent Document 1, the exhaust switching valve is not sufficiently closed due to foreign matter being caught in the single turbo mode (a state in which the valve is not closed while the valve is open, hereinafter referred to as open sticking). 2 Exhaust may flow into the turbine. As a result, the compressor of the second supercharger is rotated, and the compressed intake air is supplied to the intake passage on the downstream side. At this time, since the intake switching valve is in the closed state, the compressed intake air is not supplied to the compressor of the first supercharger and loses its place, and flows back toward the compressor of the second supercharger, and the second There is a risk of backflow to the upstream side of the compressor of the turbocharger.

The present invention has been devised in view of these points, and is a single turbo mode and a first supercharger that include a first supercharger and a second supercharger and operates only the first supercharger. Provided is an internal combustion engine control device capable of determining an abnormality of an exhaust switching valve (opening and sticking of an exhaust switching valve) in a single turbo mode in an internal combustion engine system having a twin turbo mode operating mode for operating the second supercharger. That is the issue.

In order to solve the above problems, the first invention of the present invention is the first supercharger, the second supercharger, and the turbocharger of the first supercharger while being guided to exhaust from the internal combustion engine. An upstream exhaust passage that connects the upstream side of the first turbocharger and the upstream side of the second turbocharger, which is the turbocharger of the second turbocharger, and an upstream exhaust passage that is provided on the upstream exhaust passage and exhausts only to the first turbocharger. An exhaust switching valve that switches between a state in which exhaust flows and a state in which exhaust flows through both the first turbocharger and the second turbocharger, and intake on the downstream side of the first compressor, which is the compressor of the first supercharger, and the intake of the internal combustion engine. The first downstream intake passage that communicates with the manifold, the second downstream intake passage that communicates the downstream side of the second compressor, which is the compressor of the second supercharger, and the intake manifold, and the second downstream intake passage. An intake switching valve that switches between a state in which the intake air from the second compressor is supplied to the intake manifold and a state in which the intake air from the second compressor is not supplied to the intake manifold, and the second downstream side. An intake bypass passage provided on the upstream side of the intake switching valve of the intake passage and bypassing the intake air from the downstream side of the second compressor to the upstream side of the first compressor, and an intake bypass passage provided on the intake bypass passage and described above. An intake bypass valve that switches between a state in which intake air is bypassed from the two compressors to the first compressor and a state in which intake air is not bypassed from the second compressor to the first compressor is provided on the inflow side of the intake air of the second compressor. A control device for an internal combustion engine, comprising: a compressor intake temperature detecting means for detecting the temperature of the intake air flowing into the second compressor, and the control device for operating the internal combustion engine. Based on the state, the single turbo mode in which only the first supercharger is supercharged, the twin turbo mode in which the first supercharger and the second supercharger are supercharged, and the twin from the single turbo mode Switching to the turbo mode Switching between the 1st and 2nd switching modes, which are the transitional modes, the control device closes the exhaust switching valve, the intake switching valve, and the intake bypass valve in the single turbo mode. In the twin turbo mode, each of the exhaust switching valve and the intake switching valve is opened, the intake bypass valve is closed, and in the 1.2 switching mode, the exhaust switching valve and the intake bypass are set. Open each of the valves and switch the intake air. When the valve is closed and the compressor intake temperature, which is the temperature of intake air to the second compressor detected by the compressor intake air temperature detecting means, exceeds a predetermined threshold value in the single turbo mode, the exhaust switching valve is abnormal. It is a control device of an internal combustion engine that determines that.

Next, the second invention of the present invention is the control device for the internal combustion engine according to the first invention, when the control device determines that the exhaust switching valve is abnormal, and the single. In the turbo mode, it is an internal combustion engine control device that opens the intake bypass valve.

Next, the third invention of the present invention is the control device for the internal combustion engine according to the first or second invention, and the internal combustion engine includes an outside air temperature detecting means for detecting the outside air temperature which is the temperature of the outside air. The control device is a control device for an internal combustion engine that obtains the predetermined threshold value based on the outside air temperature detected by the outside air temperature detecting means.

According to the first invention, in the case of the single turbo mode, it can be determined that the exhaust switching valve is abnormal (opening and sticking of the exhaust switching valve) based on the change in the intake air temperature on the upstream side of the second compressor. It is convenient for the driver to be able to recognize the abnormality of the exhaust switching valve and take appropriate measures such as repair.

According to the second invention, in response to an abnormality in the exhaust switching valve (opening and sticking of the exhaust switching valve), the intake air is bypassed to the upstream side of the first compressor, so that the intake air flows back to the upstream side of the second compressor. Can be resolved. As a result, it is possible to suppress the generation of abnormal noise caused by the backflow of the intake air to the rotating second compressor.

According to the third invention, even when the outside air temperature changes, the change in the intake air temperature on the upstream side of the second compressor can be accurately detected, and an abnormality in the exhaust switching valve (open sticking of the exhaust switching valve) can be detected. Can be judged appropriately.

It is a figure explaining the example of the whole schematic structure of the internal combustion engine system (internal combustion engine system including two superchargers) of this invention. In this embodiment, it is a flowchart explaining an example of the processing procedure (the whole processing procedure) of a control device. It is a figure explaining the open / closed state and the exhaust / intake state of each of the exhaust switching valve, the intake switching valve, and the intake bypass valve in the single turbo mode (normal state). It is a figure explaining the relationship between the open / closed state of the exhaust switching valve and the like in the single turbo mode (normal state), the rotation speed of the second supercharger, and the like. It is a figure explaining the open / closed state and the exhaust / intake state of each of the exhaust switching valve, the intake switching valve, and the intake bypass valve in the single turbo mode (when the exhaust switching valve is open and stuck). It is a figure explaining the open / closed state of each of the exhaust switching valve, the intake switching valve, and the intake bypass valve and the state of exhaust / intake in the single turbo mode (when the exhaust switching valve is open and stuck: with intake bypass valve open control). It is a figure explaining the relationship between the open / closed state of the exhaust switching valve and the like in the single turbo mode (when the exhaust switching valve is open and stuck: with the intake bypass valve open control) and the rotation speed of the second supercharger.

● [Example of the overall schematic configuration of the internal combustion engine system 1 (Fig. 1)]
Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. First, an example of an overall schematic configuration of an internal combustion engine system 1 having an internal combustion engine control device 70 will be described with reference to FIG. In the description of the present embodiment, an internal combustion engine 10 (for example, a diesel engine) mounted on a vehicle will be used as an example of the internal combustion engine. Further, in the example of the internal combustion engine system 1 shown in FIG. 1, two turbochargers, a first supercharger 31 and a second supercharger 32, are arranged in parallel, but the intake bypass passage 11CB and intake air are described later. By having the bypass valve 61, it is possible to supercharge the second supercharger 32 and the first supercharger 31 in series.

Hereinafter, the entire internal combustion engine system 1 will be described in order from the intake side (upper side of FIG. 1) to the exhaust side (lower side of FIG. 1) with reference to FIG. On the inflow side of the intake passage 11A, an intake flow rate detecting means 21 (for example, an intake flow rate sensor), an atmospheric pressure detecting means 22D (for example, a pressure sensor), and an intake air temperature detecting means 22E (for example, a temperature sensor) are provided. There is. The intake flow rate detecting means 21 outputs a detection signal according to the flow rate of the air sucked by the internal combustion engine 10 to the control device 70. The atmospheric pressure detecting means 22D outputs a detection signal corresponding to the atmospheric pressure (atmospheric pressure) of the atmosphere to the control device 70, and the intake air temperature detecting means 22E (corresponding to the outside air temperature detecting means) is sucked by the internal combustion engine 10. A detection signal corresponding to the outside air temperature (the temperature of the air in the intake passages 11A, 11B1 and 11B2) of the outside air (air) is output to the control device 70. The outflow side of the intake passage 11A is bifurcated into the intake passages 11B1 and 11B2, and is connected to the inflow side of the intake passage 11B1 and the inflow side of the intake passage 11B2.

The outflow side of the intake passage 11B1 is connected to the inflow side of the first compressor 31A of the first supercharger 31 (first turbocharger). Further, the outflow side of the intake bypass passage 11CB is connected in the middle of the intake passage 11B1. The outflow side of the first compressor 31A is connected to the inflow side of the first downstream intake passage 11C1, and the outflow side of the first downstream intake passage 11C1 is merged with the outflow side of the second downstream intake passage 11C2 to take in air. It is connected to the inflow side of the passage 11D. The first downstream intake passage 11C1 communicates the downstream side of the first compressor 31A, which is the compressor of the first supercharger 31, with the intake manifold 11E of the internal combustion engine 10. Further, the second downstream intake passage 11C2 communicates the downstream side of the second compressor 32A, which is the compressor of the second supercharger 32, with the intake manifold 11E of the internal combustion engine 10. The first compressor 31A is rotationally driven by the first turbine 31B that rotates using the energy of the exhaust gas, compresses the air sucked from the intake passage 11B1, and discharges (supercharges) the air to the first downstream intake passage 11C1. ).

The outflow side of the intake passage 11B2 is connected to the inflow side of the second compressor 32A of the second supercharger 32 (second turbocharger). On the inflow side of the intake air of the second compressor 32A, a compressor intake air temperature detecting means 32F (for example, a temperature sensor) for detecting the temperature of the intake air flowing into the second compressor 32A (compressor intake air temperature) is provided. By providing the compressor intake air temperature detecting means 32F not on the outflow side of the intake air of the second compressor 32A but on the inflow side, the compressor intake air temperature can be accurately detected without being affected by the temperature fluctuation due to the compression of the second compressor 32A.

The outflow side of the second compressor 32A is bifurcated into the second downstream side intake passage 11C2 and the intake bypass passage 11CB, and is connected to the inflow side of the second downstream side intake passage 11C2 and the inflow side of the intake bypass passage 11CB. Has been done. The intake bypass passage 11CB is provided on the upstream side of the intake switching valve 62 of the second downstream side intake passage 11C2, and bypasses the intake air from the downstream side of the second compressor 32A to the upstream side of the first compressor 31A.

The outflow side of the second downstream side intake passage 11C2 merges with the outflow side of the first downstream side intake passage 11C1 and is connected to the inflow side of the intake passage 11D. Further, the second downstream intake passage 11C2 is provided with an intake switching valve 62 that opens / closes (opens / closes) the second downstream intake passage 11C2 based on a control signal from the control device 70. As a result, the intake switching valve 62 switches between a state in which the intake air from the second compressor is supplied to the intake manifold and a state in which the intake air from the second compressor is not supplied to the intake manifold.

The outflow side of the intake bypass passage 11CB is connected to the intake passage 11B1. Further, the intake bypass passage 11CB is provided with an intake bypass valve 61 that opens and closes the intake bypass passage 11CB based on a control signal from the control device 70. The intake bypass valve 61 switches between a state in which the intake air is bypassed from the second compressor 32A to the first compressor 31A and a state in which the intake air is not bypassed from the second compressor 32A to the first compressor 31A.

The second turbine 32B, which rotationally drives the second compressor 32A, is rotationally driven by the energy of the exhaust gas when the exhaust switching valve 63 is opened. The exhaust switching valve 63 opens and closes the exhaust passage 12B2 based on the control signal from the control device 70. When the exhaust switching valve 63 is opened and the second turbine 32B is rotationally driven, the control device 70 opens one of the intake switching valve 62 and the intake bypass valve 61 and closes the other. Further, when the exhaust switching valve 63 is closed, the control device 70 closes both the intake switching valve 62 and the intake bypass valve 61.

When the second compressor 32A is rotationally driven by the second turbine 32B, when the intake switching valve 62 is in the open state and the intake bypass valve 61 is in the closed state, the air sucked from the intake passage 11B2 is compressed and the second compressor 32A is second. It is discharged (supercharged) to the downstream intake passage 11C2. Further, when the second compressor 32A is rotationally driven by the second turbine 32B, when the intake switching valve 62 is in the closed state and the intake bypass valve 61 is in the open state, the air sucked from the intake passage 11B2 is compressed and intake air is taken. Discharge (supercharge) to the bypass passage 11CB.

The inflow side of the intake passage 11D is connected to the outflow side of the first downstream side intake passage 11C1 and the outflow side of the second downstream side intake passage 11C2, and the outflow side of the intake passage 11D is connected to the inflow side of the intake manifold 11E. Has been done. The supercharging pressure detecting means for detecting the supercharging pressure is provided in any of the first downstream intake passage 11C1, the intake passage 11D, and the intake manifold 11E, which are downstream of the first compressor 31A of the first supercharger 31. A 22A (eg, pressure sensor) is provided. The supercharging pressure detecting means 22A outputs a detection signal corresponding to the pressure of the supercharged intake air to the control device 70.

The outflow side of the intake manifold 11E is connected to each cylinder of the internal combustion engine 10.

The internal combustion engine 10 has a plurality of cylinders, and injectors 43A to 43H are provided in each cylinder. Fuel is supplied to the injectors 43A to 43H from the common rail 42 via a fuel pipe, and the injectors 43A to 43H are driven by a control signal from the control device 70 to inject fuel into the respective cylinders.

Fuel is supplied to the common rail 42 from a fuel pressure adjusting pump 41 driven based on a control signal from the control device 70. Further, the common rail 42 is provided with a fuel pressure detecting means 23 (for example, a pressure sensor) for detecting the pressure of the fuel in the common rail 42. The fuel pressure detecting means 23 outputs a detection signal corresponding to the detected fuel pressure to the control device 70. The control device 70 controls the fuel pressure adjusting pump 41 so that the fuel pressure based on the detection signal from the fuel pressure detecting means 23 becomes the target fuel pressure.

The internal combustion engine 10 is provided with a rotation detecting means 25 (for example, a rotation sensor), a coolant temperature detecting means 24 (for example, a temperature sensor), and the like. The rotation detection means 25 outputs a detection signal corresponding to the rotation speed of the crankshaft of the internal combustion engine 10 (that is, the engine rotation speed) to the control device 70. The coolant temperature detecting means 24 detects the temperature of the cooling coolant circulated in the internal combustion engine 10 and outputs a detection signal corresponding to the detected temperature to the control device 70.

In the upstream exhaust passage 12BB, exhaust gas from the internal combustion engine 10 is guided, and the upstream side of the first turbine 31B, which is the turbine of the first supercharger 31, and the second turbine, which is the turbine of the second supercharger 32. It communicates with the upstream side of 32B. A part of the upstream exhaust passage 12BB on the upstream side of the first turbine 31B is an exhaust passage 12B1, and a part of the upstream side of the second turbine 32B is an exhaust passage 12B2.

The inflow side of the exhaust manifolds 12A1 and 12A2 is connected to the exhaust side of the internal combustion engine 10, the inflow side of the exhaust passage 12B1 is connected to the outflow side of the exhaust manifold 12A1, and the inflow side of the exhaust passage 12B2 is connected to the outflow side of the exhaust manifold 12A2. It is connected. The outflow side of the exhaust passage 12B1 is connected to the inflow side of the first turbine 31B, and is connected to the inflow side of the second turbine 32B of the exhaust passage 12B2. Further, an exhaust switching valve 63 for switching between a state in which exhaust gas flows only in the first turbine 31B and a state in which exhaust gas flows in both the first turbine 31B and the second turbine 32B is provided on the exhaust passage 12B2 (upstream exhaust passage 12BB). Has been done. The exhaust switching valve 63 opens and closes (open / closed state) the exhaust passage 12B2 based on the control signal from the control device 70.

The exhaust manifold 12A1 is provided with an exhaust pressure detecting means 22F (for example, a pressure sensor) for detecting the pressure of the exhaust gas in the exhaust manifold 12A1. The exhaust pressure detecting means 22F outputs a detection signal corresponding to the pressure of the exhaust gas in the exhaust manifold 12A1 to the control device 70. Similarly, the exhaust manifold 12A2 is provided with an exhaust pressure detecting means 22G (for example, a pressure sensor) for detecting the pressure of the exhaust in the exhaust manifold 12A2. The exhaust pressure detecting means 22G outputs a detection signal corresponding to the pressure of the exhaust in the exhaust manifold 12A2 to the control device 70.

The inflow side of the exhaust passage 12C2 is connected to the outflow side of the second turbine 32B of the second supercharger 32, and the outflow side of the exhaust passage 12C2 is connected in the middle of the exhaust passage 12C1. The inflow side of the exhaust passage 12C1 is connected to the outflow side of the first turbine 31B of the first supercharger 31, and the outflow side of the exhaust passage 12C1 is connected to the inflow side of the oxidation catalyst 51. The exhaust passage 12D, which is downstream from the connection point between the exhaust passage 12C1 and the exhaust passage 12C2, is connected to the inflow side of the oxidation catalyst 51. Further, the exhaust passage 12C1 includes an exhaust pressure detecting means 22B (for example, a pressure sensor) for detecting the exhaust pressure in the exhaust passage 12C1 and an exhaust temperature detecting means 26 (for example, a temperature sensor) for detecting the temperature of the exhaust in the exhaust passage 12C1. Etc. are provided. The exhaust pressure detecting means 22B outputs a detection signal corresponding to the detected pressure to the control device 70, and the exhaust temperature detecting means 26 outputs a detection signal corresponding to the detected temperature to the control device 70.

In the first turbine 31B of the first supercharger 31, the flow velocity of the exhaust gas that rotationally drives the first turbine 31B can be adjusted (the opening degree of the flow path that guides the exhaust gas to the first turbine 31B can be adjusted). A variable nozzle 31C is provided. The variable nozzle 31C is operated by a nozzle driving means 31D (for example, an electric motor) that operates in response to a control signal from the control device 70. Further, the nozzle opening degree detecting means 31E (for example, a rotation angle sensor) outputs a detection signal according to the operating state of the nozzle driving means 31D (in this case, the rotation angle of the electric motor) according to the opening degree of the variable nozzle 31C. Output to. The control device 70 controls the nozzle driving means 31D so that the opening degree of the variable nozzle 31C obtained based on the detection signal from the nozzle opening degree detecting means 31E becomes the target nozzle opening degree. The opening degree of the variable nozzle 31C is adjusted from the control device 70 according to the operating state of the internal combustion engine 10. The same applies to the variable nozzle 32C, the nozzle driving means 32D, and the nozzle opening degree detecting means 32E of the second turbine 32B of the second supercharger 32, and the description thereof will be omitted.

The outflow side of the oxidation catalyst 51 is connected to the inflow side of the DPF 52 (fine particle collection filter). The oxidation catalyst 51 oxidizes and purifies HC (hydrocarbon) and CO (carbon monoxide) in the exhaust gas of the internal combustion engine 10.

The outflow side of the DPF 52 is connected to the inflow side of the urea SCR53. The DPF 52 collects fine particles in the exhaust. Further, the DPF 52 is provided with a differential pressure detecting means 22C (for example, a differential pressure sensor) for detecting the pressure difference between the inflow side and the outflow side of the DPF 52. The differential pressure detecting means 22C outputs a detection signal corresponding to the pressure difference between the inflow side and the outflow side of the DPF 52 to the control device 70. The control device 70 can estimate the amount of fine particles deposited on the DPF 52 from the differential pressure based on the detection signal from the differential pressure detecting means 22C.

The urea SCR53 uses urea injected from a urea water addition valve (not shown) to reduce and purify NOx (nitrogen oxides) in the exhaust gas.

The vehicle speed detecting means 22H (for example, a vehicle speed sensor) is provided in the vicinity of the wheels of the vehicle, for example, and outputs a detection signal corresponding to the rotation speed of the wheels to the control device 70.

The accelerator pedal depression amount detecting means 27 (for example, an accelerator pedal depression angle sensor) is provided on the accelerator pedal, and outputs a detection signal according to the depression amount of the accelerator pedal by the driver to the control device 70.

The control device 70 has at least a control means 71 (CPU) and a storage means 73. The control device 70 detects the operating state of an internal combustion engine (internal combustion engine system) having a plurality of turbochargers, and controls the amount of fuel injected into the cylinder of the internal combustion engine based on the detected operating state. The control device 70 (control means 71) is not limited to the above-mentioned detection means and each actuator shown in FIG. 1, and operates the internal combustion engine 10 based on detection signals from various detection means including the above-mentioned detection means. Detect the condition. The control device 70 (control means 71) includes various injectors 43A to 43H, an intake bypass valve 61, an intake switching valve 62, an exhaust switching valve 63, nozzle driving means 31D and 32D, and a fuel pressure adjusting pump 41. Control the actuator of. The abnormality lamp 75 is a display device such as an LED, and is controlled by the control device 70 and turned on when it is determined that the exhaust switching valve 63 is abnormal when the operation mode of the internal combustion engine described later is "single turbo mode". (Lights up). The storage means 73 is, for example, a storage device such as a Flash-ROM, and stores programs, data, and the like for executing a process described later.

Each of the intake bypass valve 61, the intake switching valve 62, and the exhaust switching valve 63 is controlled to be in an open state or a closed state by the control device 70, and a plurality of turbochargers (in this case, in this case) are controlled according to the operating state of the internal combustion engine 10. It is a switching means capable of switching the number of turbochargers to be operated from among the two turbochargers).

● [Processing procedure of the control device 70 in the present embodiment (FIG. 2)]]
Next, an example of the processing procedure of the control device 70 (control means 71) (see FIG. 1) in the present embodiment will be described with reference to the flowchart shown in FIG. The process shown in FIG. 2 is started, for example, at a predetermined time interval (for example, an interval of several [ms] to several tens [ms]), and when activated, the control device 70 (control means 71) processes to step S010. To proceed.

In step S010, the control device 70 performs a determination process of the operation mode of the internal combustion engine (existing process), stores the determination result as the operation mode of the internal combustion engine, and proceeds to the process to step S015. The (existing process) means a process executed in the existing control of the internal combustion engine. Further, the rotation speed of the second supercharger 32 and the like are acquired and stored in (existing processing).

Based on the operating state of the internal combustion engine 10, the control device 70 sets the operation modes of the internal combustion engine 10 to "single turbo mode", "twin turbo mode", "1.2 switching mode", and "2.1". Switch to "switching mode". The "single turbo mode" is an operation mode in which only the first supercharger 31 supercharges, and the "twin turbo mode" is an operation mode in which the first supercharger 31 and the second supercharger 32 supercharge. is there. In addition, "1.2 switching mode" is a transitional mode for switching from "single turbo mode" to "twin turbo mode", and "2.1 switching mode" is from "twin turbo mode" to "single turbo mode". This is a transitional mode to switch.

In the "single turbo mode", the control device 70 closes each of the exhaust switching valve 63, the intake switching valve 62, and the intake bypass valve 61, and in the "twin turbo mode", each of the exhaust switching valve 63 and the intake switching valve 62 is closed. Make it open. Further, in the control device 70, the exhaust switching valve 63 and the intake bypass valve 61 are opened and the intake switching valve 62 is closed in the "1.2 switching mode", and the exhaust switching valve 63 is closed in the "2.1 switching mode". And the intake bypass valve 61 are opened and the intake switching valve 62 is closed.

In step S015, the control device 70 detects the temperature of the intake air flowing into the second compressor 32A based on the detection signal from the compressor intake air temperature detecting means 32F, and determines the outside air temperature from the intake air temperature detecting means 22E based on the detection signal. A predetermined threshold value is obtained based on the detection and the outside air temperature (see FIG. 1), and the process proceeds to step S020A. Specifically, the control device 70 stores the temperature detected by the compressor intake air temperature detecting means 32F as the compressor intake air temperature. Further, the control device 70 stores the temperature detected from the intake air temperature detecting means 22E (corresponding to the outside air temperature detecting means) as the outside air temperature. For example, the control device 70 obtains and stores the temperature at which the temperature rise value ΔT rises with respect to the detected outside air temperature as a predetermined threshold value (outside air temperature + temperature rise value ΔT). The temperature rise value ΔT is a value obtained in advance by an experiment or the like, and is, for example, a value of 5 ° C. to 10 ° C.

In step S020A, the control device 70 determines whether or not the operation mode of the internal combustion engine is "single turbo mode", and if it is determined to be "single turbo mode" (Yes), the process proceeds to step S025. If it is determined that the mode is not "single turbo mode" (No), the process proceeds to step S020B.

In step S020B, the control device 70 determines whether or not the operation mode of the internal combustion engine is "twin turbo mode", and if it is determined to be "twin turbo mode" (Yes), the process proceeds to step S040C. If it is determined that the mode is not "twin turbo mode" (No), the process proceeds to step S020C.

In step S020C, the control device 70 determines whether or not the operation mode of the internal combustion engine is "1.2 switching mode", and if it is determined to be "1.2 switching mode" (Yes), step S040D. If it is determined that the mode is not "1 and 2 switching mode" (No), the process proceeds to step S040E.

When the process proceeds to step S025, the control device 70 determines whether or not the compressor intake air temperature is equal to or higher than the predetermined threshold value, and when it is determined that the compressor intake air temperature is equal to or higher than the predetermined threshold value (Yes), the process proceeds to step S030. If it is determined that the compressor intake temperature is not equal to or higher than a predetermined threshold value (No), the process proceeds to step S040B. When the control device 70 determines that the compressor intake air temperature is equal to or higher than a predetermined threshold value (Yes), the control device 70 activates an internal timer provided inside, and determines that the compressor intake air temperature is not equal to or higher than the predetermined threshold value (No). Stop the internal timer.

When the process proceeds to step S030, when the control device 70 determines that the compressor intake air temperature is continuously equal to or higher than the predetermined threshold value (Yes), the process proceeds to step S040A, and when it determines that the process is not (Yes). No) proceeds to step S040B. When the control device 70 determines that the compressor intake temperature is continuously equal to or higher than the predetermined threshold value for a predetermined time (ΔS), the control device 70 determines that the exhaust switching valve 63 is abnormal (open sticking of the exhaust switching valve 63). The predetermined time ΔS is a time determined in advance by an experiment or the like and is stored, for example, 15s to 20s.

In step S040A, the control device 70 controls the intake bypass valve 61 to be in the open state so that the exhaust switching valve 63 and the intake switching valve 62 are in the closed state, and proceeds to the process in step S050A. Since the exhaust switching valve 63 is determined to be abnormal (open sticking), it is not in the open / closed state (closed state) of the control but in the open state.

In step S040B, the control device 70 controls each of the exhaust switching valve 63, the intake switching valve 62, and the intake bypass valve 61 so as to be in a closed state (“single turbo mode”), and proceeds to step S050B. Since the exhaust switching valve 63 is determined to be abnormal (open sticking), it is not in the open / closed state (closed state) of the control but in the open state.

In step S040C, the control device 70 controls the intake bypass valve 61 to be in the closed state so that the exhaust switching valve 63 and the intake switching valve 62 are in the open state (“twin turbo mode”), and proceeds to step S050B. And proceed with the process.

In step S040D, the control device 70 controls the intake switching valve 62 to be in the closed state so that the exhaust switching valve 63 and the intake bypass valve 61 are in the open state (“1.2 switching mode”). Proceed to process to S050B.

In step S040E, the control device 70 controls the intake bypass valve 61 to be in the open state so that the exhaust switching valve 63 and the intake switching valve 62 are in the closed state (“2.1 switching mode”). Proceed to process to S050B.

In step S050A, the control device 70 controls the abnormality lamp 75 to turn on (lights up), and ends the entire process.

In step S050B, the control device 70 controls the abnormality lamp 75 to be turned off (off), and ends the entire process.

● [Examples of open / closed state of exhaust switching valve, intake switching valve, intake bypass valve and exhaust / intake state (Figs. 3 to 7)]
3 to 7 are diagrams for explaining the open / closed state and the exhaust / intake state of each of the exhaust switching valve 63, the intake switching valve 62, and the intake bypass valve 61 in the “single turbo mode”. The black arrow indicates the intake flow on the intake side, and the white arrow indicates the exhaust flow on the exhaust side. Further, in the exhaust switching valve 63, the intake switching valve 62, and the intake bypass valve 61, the valves shown in black indicate the valves in the closed state, and the valves shown in white indicate the valves in the open state. There is. In addition, the valve shown in half black and half white indicates an abnormal state (valve open sticking). Further, the rotation speed of the second supercharger 32, the intake air temperature of the second compressor 32A, and the state of the abnormal lamp are shown.

3 and 4 are examples in the case where the exhaust switching valve 63, the intake switching valve 62, and the intake bypass valve 61 are operating normally in the “single turbo mode”. As shown in FIG. 3, each of the exhaust switching valve 63, the intake switching valve 62, and the intake bypass valve 61 is closed, and only the first supercharger 31 supercharges the internal combustion engine 10. As shown in FIG. 4, the exhaust switching valve 63 is in the closed state (normal), the second compressor 32A does not rotate, and the intake air temperature of the second compressor 32A is the intake air temperature (outside air temperature) of the intake passage 11B2.

5 and 7 are examples in the case where the exhaust switching valve 63 is open-fixed and determined to be abnormal in the “single turbo mode”. As shown in FIGS. 5 and 7, when the intake switching valve 62 and the intake bypass valve 61 are in the closed state and the exhaust switching valve 63 changes from the closed state (normal) to the open sticking (abnormal) state, the exhaust is exhaust-switched. It is supplied to the second turbine 32B through the valve 63 to rotate the second compressor 32A. The intake air compressed by the second compressor 32A is supplied to the downstream side. However, since each of the intake switching valve 62 and the intake bypass valve 61 is in the closed state, the intake air supplied from the second compressor 32A does not flow to each of the second downstream intake passage 11C2 and the intake bypass passage. It flows back toward the second compressor 32A. Further, the intake air that has flowed back toward the second compressor 32A flows back to the upstream side. The temperature of the intake air flowing back through the second compressor 32A is higher than the outside air temperature because it is compressed.

As shown in FIGS. 6 and 7, the control device 70 switches the exhaust gas when the compressor intake air temperature continues for a predetermined threshold value (outside air temperature + temperature rise value ΔT) for a predetermined time (ΔS) or more in the “single turbo mode”. It is determined that the valve 63 is open-fixed (abnormal), the intake bypass valve 61 is opened, and the abnormal lamp is turned ON. As a result, it is possible to notify the driver that an abnormality has occurred in the internal combustion engine 10 and prompt the driver to take measures such as repair.

The internal combustion engine system of the present invention is not limited to the configuration, structure, processing procedure, operation, etc. described in the present embodiment, and various changes, additions, and deletions can be made without changing the gist of the present invention. Further, the internal combustion engine system is not limited to the one shown in the example of FIG. 1, and can be applied to various internal combustion engine systems.

In the description of the present embodiment, an internal combustion engine system having two superchargers, a first supercharger and a second supercharger, has been described as an example, but an internal combustion engine having three or more superchargers has been described. Is also applicable. Further, in the description of the present embodiment, an example of a configuration in which the first supercharger and the second supercharger are supercharged in parallel (a configuration in which supercharging can be performed in series) has been described. It is possible to apply the present invention regardless of whether the turbocharger is supercharged in parallel or supercharged in series.

In the description of the present embodiment, in order to notify the driver of the abnormality of the exhaust switching valve 63, an example of using a display device such as an abnormality lamp 75 has been described, but the present invention is not limited to this, and the display device is used or instead. The abnormality may be notified by a sound generating means (for example, a speaker or the like). In this case, the sound generating means outputs a warning sound notifying the occurrence of the abnormality and / or a voice transmitting the content of the abnormality.

In the description of this embodiment,

Further, the numerical values used in the description of the present embodiment are examples, and are not limited to these numerical values. Further, the above (≧), the following (≦), the larger (>), the less than (<), etc. may or may not include the equal sign.

1 Internal combustion engine system 10 Internal combustion engine 11A, 11B1, 11B2, 11D Intake passage 11C1 1st downstream intake passage 11C2 2nd downstream intake passage 11CB Intake bypass passage 11E Intake manifold 12A1, 12A2 Exhaust manifold 12B1, 12B2, 12C1, 12C2 Passage 12BB Upstream exhaust passage 21 Intake flow rate detecting means 22A Supercharging pressure detecting means 22B Exhaust pressure detecting means 22C Differential pressure detecting means 22D Atmospheric pressure detecting means 22E Intake temperature detecting means (outside air temperature detecting means)
22F, 22G Exhaust pressure detecting means 22H Vehicle speed detecting means 24 Coolant temperature detecting means 25 Rotation detecting means 26 Exhaust temperature detecting means 27 Accelerator pedal depression amount detecting means 31 First supercharger 31A First compressor 32A Second compressor 31B First Turbine 32B 2nd turbine 31C, 32C Variable nozzle 31D, 32D Nozzle drive means 31E, 32E Nozzle opening detection means 32 Second supercharger 41 Fuel pressure adjustment pump 51 Oxidation catalyst 52 DPF
53 Urea SCR
61 Intake bypass valve 62 Intake switching valve 63 Exhaust switching valve 70 Control device 71 Control means 73 Storage means

Claims (3)

The first supercharger and the second supercharger,
The exhaust gas from the internal combustion engine is guided, and the upstream side that communicates between the upstream side of the first turbine, which is the turbine of the first supercharger, and the upstream side of the second turbine, which is the turbine of the second supercharger. Exhaust passage and
An exhaust switching valve provided on the upstream exhaust passage and switching between a state in which exhaust gas flows only in the first turbine and a state in which exhaust gas flows in both the first turbine and the second turbine.
The downstream side of the first compressor, which is the compressor of the first supercharger, and the first downstream side intake passage that communicates the intake manifold of the internal combustion engine,
A second downstream intake passage that communicates the downstream side of the second compressor, which is the compressor of the second supercharger, with the intake manifold.
An intake switching valve provided in the second downstream intake passage to switch between a state in which the intake air from the second compressor is supplied to the intake manifold and a state in which the intake air from the second compressor is not supplied to the intake manifold. When,
An intake bypass passage provided on the upstream side of the intake switching valve of the second downstream side intake passage and bypassing the intake air from the downstream side of the second compressor to the upstream side of the first compressor.
An intake bypass valve provided on the intake bypass passage that switches between a state in which intake air is bypassed from the second compressor to the first compressor and a state in which intake air is not bypassed from the second compressor to the first compressor.
A control device for an internal combustion engine, which is provided on the inflow side of the intake air of the second compressor and is provided with a compressor intake air temperature detecting means for detecting the temperature of the intake air flowing into the second compressor, and controls the internal combustion engine. hand,
The control device is
Based on the operating condition of the internal combustion engine
The single turbo mode that supercharges only with the first supercharger and
The twin turbo mode in which the first supercharger and the second supercharger supercharge,
Switching from the single turbo mode to the twin turbo mode Switching between the 1 and 2 switching modes, which are the transitional modes,
The control device is
In the single turbo mode, the exhaust switching valve, the intake switching valve, and the intake bypass valve are each closed.
In the twin turbo mode, each of the exhaust switching valve and the intake switching valve is opened, and the intake bypass valve is closed.
In the 1 and 2 switching modes, the exhaust switching valve and the intake bypass valve are each opened, and the intake switching valve is closed.
In the single turbo mode, when the compressor intake temperature, which is the temperature of intake air to the second compressor detected by the compressor intake air temperature detecting means, exceeds a predetermined threshold value, it is determined that the exhaust switching valve is abnormal.
Control device for internal combustion engine. The control device for an internal combustion engine according to claim 1.
The control device is
When it is determined that the exhaust switching valve is abnormal, and in the case of the single turbo mode, the intake bypass valve is opened.
Control device for internal combustion engine. The control device for an internal combustion engine according to claim 1 or 2.
The internal combustion engine is provided with an outside air temperature detecting means for detecting the outside air temperature, which is the temperature of the outside air.
The control device is
The predetermined threshold value is obtained based on the outside air temperature detected by the outside air temperature detecting means.
Control device for internal combustion engine.

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