Engine system

Abstract

To detect early and extinguish early a fire in an air cleaner.SOLUTION: An engine system comprises: an engine; an intake flow passage; an exhaust flow passage; an air cleaner provided at the intake port of the intake flow passage; an air flow meter provided downstream of the air cleaner; an exhaust valve provided in the exhaust flow passage; a valve provided so as to allow the intake flow passage and the exhaust flow passage to shut off from or communicating with each other; and a control device that controls opening and closing of the exhaust valve and the valve. The control device determines presence or absence of occurrence of a fire in the air cleaner on the basis of the intake air volume detected by the air flow meter, and if determining that a fire has occurred, closes the exhaust valve and the valve to store exhaust gas in the exhaust flow passage, and then opens the valve to cause the exhaust gas stored in the exhaust flow passage to flow back through the intake flow passage to the air cleaner.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an engine system. [Background technology]

[0002] The air cleaner is equipped with a filter that removes foreign matter (e.g., dust and dirt) contained in the air drawn in through the intake port while the vehicle is moving. If a spark (e.g., a lit cigarette) is drawn in through the intake port along with the air while the vehicle is moving, the spark may ignite the air cleaner filter, causing a fire. Air cleaners generally do not have any equipment for detecting or extinguishing fires. As a result, fires that break out in air cleaners are difficult to detect early and can easily develop into large-scale fires such as vehicle fires.

[0003] Therefore, in the technology described in Patent Document 1, a temperature sensor is installed in the intake passage, and a fire in the air cleaner is detected based on whether the temperature detected by the temperature sensor is equal to or higher than a threshold. Furthermore, if a fire in the air cleaner is detected, the fuel supply to the internal combustion engine is stopped, and the intake passage and exhaust passage are closed. This prevents the fire from spreading and minimizes damage to the vehicle and internal combustion engine. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2018-048575 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the technology described in Patent Document 1 does not have a means for extinguishing a fire in an air cleaner. Therefore, even if a fire in an air cleaner is detected, the driver or firefighters must carry out firefighting activities such as spraying fire extinguishing agents or spraying water to extinguish the fire, which is a problem.

[0006] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an engine system that is capable of detecting a fire in an air cleaner early and extinguishing the fire early. [Means for solving the problem]

[0007] In order to solve the above problem, an engine system according to one embodiment of the present invention comprises: The engine and an intake passage connected to the engine; an exhaust flow path connected to the engine; an air cleaner provided at an intake port of the intake flow path; an air flow meter provided in the intake passage downstream of the air cleaner; an exhaust valve provided in the exhaust flow path; a valve that is provided so as to be able to block or connect the intake passage and the exhaust passage; a control device for controlling the exhaust valve and the opening and closing of the valve; Equipped with The control device determining whether or not a fire has occurred in the air cleaner based on the intake air volume detected by the air flow meter; If it is determined that a fire has occurred, the exhaust valve and the valve are closed to store exhaust gas in the exhaust flow path, and then the valve is opened to cause the exhaust gas stored in the exhaust flow path to flow back to the air cleaner through the intake flow path. [Effects of the Invention]

[0008] According to the present invention, it is possible to detect a fire in an air cleaner early and extinguish the fire early. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a schematic diagram showing a schematic configuration of an engine system according to a first embodiment of the present invention. [Figure 2] 2 is a block diagram showing the configuration of a control device included in the engine system shown in FIG. 1. FIG. [Figure 3] 4 is a flowchart showing a fire extinguishing process performed by the engine system according to the first embodiment. [Figure 4] FIG. 4 is a schematic diagram showing the general configuration of an engine system according to a second embodiment of the present invention. [Figure 5] 10 is a flowchart showing a fire extinguishing process performed by an engine system according to a second embodiment. [Figure 6] FIG. 10 is a schematic diagram showing the general configuration of an engine system according to a third embodiment of the present invention. [Figure 7] 10 is a flowchart showing a fire extinguishing process performed by an engine system according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Specific dimensions, materials, numerical values, etc. shown in the embodiments are merely examples for facilitating understanding of the invention and do not limit the present invention unless otherwise specified. In this specification and drawings, elements having substantially the same functions and configurations are designated by the same reference numerals to avoid redundant explanation, and elements not directly related to the present invention are not shown.

[0011] [First embodiment] (Configuration of engine system 100) An engine system 100 according to a first embodiment of the present invention will be described with reference to Fig. 1. Fig. 1 is a schematic diagram showing the general configuration of the engine system 100 according to the first embodiment.

[0012] As shown in FIG. 1, the engine system 100 includes an engine 10, an intake passage 20, an exhaust passage 30, an EGR passage 40, and a control device 50.

[0013] The engine 10 is, for example, a horizontally opposed engine in which a plurality of cylinders 11 are arranged opposite each other. However, the engine 10 may be an engine other than a horizontally opposed engine. A piston 12 is slidably provided within the cylinder 11. A combustion chamber 13 is defined by the inner circumferential surface of the cylinder 11 and the crown surface of the piston 12. One end of a connecting rod 14 is connected to the piston 12. The other end of the connecting rod 14 is connected to a crankshaft 15. The crankshaft 15 is rotatably supported by a bearing (not shown) within a crank chamber 16.

[0014] Each cylinder 11 is formed with an intake port 17 and an exhaust port 18. The intake port 17 and the exhaust port 18 are in communication with the combustion chamber 13. The combustion chamber 13 is in communication with an intake passage 20 via the intake port 17, and is in communication with an exhaust passage 30 via the exhaust port 18. The intake port 17 is opened and closed by an intake valve (not shown). The exhaust port 18 is opened and closed by an exhaust valve (not shown). By driving the intake valve and the exhaust valve, intake air is supplied to the combustion chamber 13 and exhaust gas is discharged from the combustion chamber 13.

[0015] The intake flow path 20 is connected to the engine 10. The intake flow path 20 is a flow path through which intake air, which is air supplied to the combustion chamber 13 of the engine 10, flows. An air cleaner 21 is provided at an intake port upstream of the intake flow path 20. The air cleaner 21 removes foreign matter contained in the air taken into the intake flow path 20. For this reason, the air cleaner 21 is provided with a filter for removing foreign matter contained in the air.

[0016] An air flow meter 22 is provided in the intake flow path 20 downstream of the air cleaner 21. For example, the air flow meter 22 is provided at the exhaust port of the air cleaner 21. The air flow meter 22 measures the amount of air taken into the intake flow path 20.

[0017] A throttle valve 23 is provided in the intake passage 20 downstream of the air flow meter 22. The throttle valve 23 controls the supply of intake air from the intake passage 20 to the engine 10. The supply of intake air to the engine 10 is controlled according to the opening of the throttle valve 23. For example, when the throttle valve 23 is closed (opening is 0%), the intake passage 20 and the engine 10 are blocked from each other, and intake air is not supplied to the engine 10 through the intake passage 20. When the throttle valve 23 is open (opening is greater than 0%), the intake passage 20 and the engine 10 are connected, and intake air is supplied to the engine 10 through the intake passage 20. In this way, the throttle valve 23 controls the supply of intake air from the intake passage 20 to the engine 10 by blocking or connecting the intake passage 20 and the engine 10 according to its opening and closing.

[0018] As described above, the combustion chamber 13 of the engine 10 is connected to the intake passage 20 via the intake port 17 and to the exhaust passage 30 via the exhaust port 18. When the intake passage 20 and the combustion chamber 13 of the engine 10 are connected by the intake valve of the intake port 17 and the combustion chamber 13 is connected by the exhaust valve of the exhaust port 18, the intake passage 20 is connected to the exhaust passage 30 via the combustion chamber 13. When the intake passage 20 and the combustion chamber 13 of the engine 10 are blocked by the intake valve of the intake port 17 or when the combustion chamber 13 is connected by the exhaust valve of the exhaust port 18, the communication between the intake passage 20 and the exhaust passage 30 is blocked. In this way, the throttle valve 23 is provided to be able to block or connect the intake passage 20 and the exhaust passage 30.

[0019] An intake manifold 20a is provided in the intake passage 20 downstream of the throttle valve 23. The intake manifold 20a branches toward each cylinder 11 of the engine 10 and is connected to the intake port 17 of each cylinder 11. Air taken into the intake passage 20 through the air cleaner 21 passes through the throttle valve 23 and is sent to the combustion chamber 13 of the engine 10 through the intake manifold 20a.

[0020] The exhaust flow path 30 is connected to the engine 10. The exhaust flow path 30 is a flow path through which exhaust gas discharged from the combustion chamber 13 of the engine 10 flows. An exhaust manifold 30a is provided on the upstream side of the exhaust flow path 30. The exhaust manifold 30a branches toward each cylinder 11 of the engine 10 and is connected to the exhaust port 18 of each cylinder 11.

[0021] A purification device 31 is provided in the exhaust flow path 30 downstream of the exhaust manifold 30a. The purification device 31 has a catalyst 32 and a filter 33. The catalyst 32 removes harmful substances contained in the exhaust gas discharged from the combustion chamber 13. For example, the catalyst 32 is a three-way catalyst containing catalytic components such as platinum (Pt), palladium (Pd), and rhodium (Rh), and removes hydrocarbons (HC), carbon monoxide (CO), and nitrogen oxides (NO X ) from the exhaust gas. The filter 33 is provided in the purification device 31 downstream of the catalyst 32. The filter 33 is a particulate filter that collects particulate matter such as soot in the exhaust gas. For example, the filter 33 is a gasoline particulate filter (GPF) or a diesel particulate filter (DPF).

[0022] An exhaust valve 34 is provided in the exhaust flow path 30 downstream of the purification device 31. The exhaust valve 34 is a valve that adjusts the flow rate of exhaust gas that passes through the exhaust flow path 30 and is discharged outside the vehicle. The flow rate of exhaust gas that is discharged outside the vehicle varies depending on the opening degree of the exhaust valve 34. The exhaust valve 34 may be, for example, an ECV (Exhaust Control Valve) that is generally provided in the exhaust flow path 30, or may be a valve that is newly provided in the exhaust flow path 30 separate from an existing ECV.

[0023] A muffler 35 is provided in the exhaust flow path 30 downstream of the exhaust valve 34. The muffler 35 reduces the noise generated when exhaust gas is discharged outside the vehicle. The exhaust gas discharged from the combustion chamber 13 of the engine 10 passes through the catalyst 32 of the purification device 31 in the exhaust flow path 30, the filter 33, and the muffler 35 in that order, before being discharged outside the vehicle.

[0024] Further, a pressure sensor 36 and a temperature sensor 37 are provided in the exhaust flow path 30. The pressure sensor 36 is a sensor that detects the pressure of exhaust gas in the exhaust flow path 30. For example, the pressure sensor 36 may be a differential pressure sensor that is typically provided in the exhaust flow path 30, or a pressure sensor that is newly provided in the exhaust flow path 30 separately from an existing differential pressure sensor. A typically provided differential pressure sensor detects the difference (differential pressure) between the pressure upstream and the pressure downstream of the filter 33 and is used to determine whether the filter 33 is clogged or not. In this embodiment, a typically provided differential pressure sensor is used as the pressure sensor 36. Therefore, the pressure sensor 36 is provided so that two measurement units are located upstream and downstream of the filter 33, respectively. This allows the existing differential pressure sensor to be effectively used as the pressure sensor 36 for detecting the pressure of exhaust gas. Note that when a newly provided pressure sensor separate from a typically provided differential pressure sensor is used as the pressure sensor 36, the location where the pressure sensor 36 is provided is not particularly limited as long as it is provided in the exhaust flow path 30.

[0025] The temperature sensor 37 is a sensor that detects the temperature of the exhaust gas in the exhaust flow path 30. For example, the temperature sensor 37 may be a temperature sensor that is typically provided in the exhaust flow path 30, or may be a temperature sensor that is newly provided in the exhaust flow path 30 in addition to an existing temperature sensor. In this embodiment, of the temperature sensors that are typically provided in the exhaust flow path 30, a temperature sensor that is provided to monitor overheating of the catalyst 32 is used as the temperature sensor 37 that detects the temperature of the exhaust gas. Therefore, the temperature sensor 37 is provided between the catalyst 32 and the filter 33. Note that when a temperature sensor that is newly provided in addition to a typically provided temperature sensor is used as the temperature sensor 37, it is only necessary that it be provided in the exhaust flow path 30, and there are no particular limitations on the location where it is installed.

[0026] The EGR (Exhaust Gas Recirculation) passage 40 is a recirculation passage that connects the intake passage 20 and the exhaust passage 30. The EGR passage 40 is a passage for recirculating exhaust gas by directly bypassing the intake passage 20 and the exhaust passage 30 without passing through the combustion chamber 13 of the engine 10. The EGR passage 40 is an example of a first EGR passage. In the engine system 100, exhaust gas discharged from the combustion chamber 13 of the engine 10 to the exhaust passage 30 is recirculated from the exhaust passage 30 to the intake passage 20 via the EGR passage 40. For example, one end of the EGR passage 40 is connected to the intake passage 20 on the downstream side of the throttle valve 23. The other end of the EGR passage 40 is connected to the exhaust passage 30 between the exhaust manifold 30a and the purification device 31. Hereinafter, the exhaust passage 30 side of the EGR passage 40 will be referred to as the upstream side, and the intake passage 20 side will be referred to as the downstream side.

[0027] Furthermore, an EGR cooler 41 is provided in the EGR passage 40. The EGR cooler 41 cools the exhaust gas that is recirculated from the exhaust passage 30 to the intake passage 20. An EGR valve 42 is provided in the EGR passage 40 downstream of the EGR cooler 41. The EGR valve 42 controls the recirculation of exhaust gas from the exhaust passage 30 to the intake passage 20. The recirculation of exhaust gas from the exhaust passage 30 to the intake passage 20 is controlled according to the opening degree of the EGR valve 42. For example, when the EGR valve 42 is closed (opening degree is 0%), the intake passage 20 and the exhaust passage 30 are blocked, and the exhaust gas in the exhaust passage 30 is not recirculated to the intake passage 20. When the EGR valve 42 is open (opening degree is greater than 0%), the intake passage 20 and the exhaust passage 30 are connected, and the exhaust gas in the exhaust passage 30 is recirculated through the EGR passage 40 to the intake passage 20. That is, the EGR valve 42 is provided so as to be able to open or close the intake passage 20 and the exhaust passage 30. The EGR valve 42 is an example of a first EGR valve.

[0028] The control device 50 communicates with each device provided in the engine system 100. For example, the control device 50 communicates with the air flow meter 22, the pressure sensor 36, the temperature sensor 37, the throttle valve 23, the exhaust valve 34, and the EGR valve 42. The control device 50 acquires various information from the air flow meter 22, the pressure sensor 36, and the temperature sensor 37, and controls the opening degrees of the throttle valve 23, the exhaust valve 34, and the EGR valve 42 based on the acquired information.

[0029] (Configuration of control device 50) The configuration of the control device 50 included in the engine system 100 according to this embodiment will be described with reference to Fig. 2. Fig. 2 is a block diagram showing the configuration of the control device 50.

[0030] 2, the control device 50 includes a processor 51, a primary memory 52, a secondary memory 53, and a communication interface 54. The processor 51, the primary memory 52, the secondary memory 53, and the communication interface 54 are connected to each other via a bus.

[0031] A program 55 is stored in the secondary memory 53. The processor 51 loads the program 55 stored in the secondary memory 53 onto the primary memory 52. The processor 51 then executes each process included in the fire extinguishing process S1, which will be described later, in accordance with instructions included in the program 55 loaded onto the primary memory 52. An example of a device that can be used as the processor 51 is an ECU (Electronic Control Unit). An example of a device that can be used as the primary memory 52 is a semiconductor RAM (Random Access Memory). An example of a device that can be used as the secondary memory 53 is an HDD (Hard Disk Drive).

[0032] The communication interface 54 is an interface for communicating via a network with each device provided in the engine system 100. Examples of interfaces that can be used as the communication interface 54 include networks such as a CAN (Controller Area Network) and a LIN (Local Interconnect Network), or an internetwork including these networks.

[0033] The program 55 for causing the processor 51 to execute the fire extinguishing process S1 may be recorded on a computer-readable non-volatile recording medium. This recording medium may be the secondary memory 53 or another recording medium. Examples of other recording media include semiconductor memory, programmable logic circuits, and disk-type recording media.

[0034] Furthermore, in this embodiment, a configuration is adopted in which the fire extinguishing process S1 is performed using a single processor (processor 51), but the present invention is not limited to this. For example, a configuration in which the fire extinguishing process S1 is performed using multiple processors may be adopted. In this case, the multiple processors that perform the fire extinguishing process S1 may be provided in a single device (control device 50) or may be distributed across multiple devices. When multiple processors are distributed across multiple devices, the multiple devices may be configured to be able to communicate with each other via a network such as CAN or LIN.

[0035] (Operation of engine system 100) The operation of the engine system 100 will be described with reference to Fig. 3. Fig. 3 is a flowchart showing the fire extinguishing process S1 executed by the engine system 100. As shown in Fig. 3, the fire extinguishing process S1 includes steps S100 to S112. The engine system 100 executes the fire extinguishing process S1 at a predetermined cycle (for example, every 1 second). Note that some of the steps S100 to S112 may be executed in parallel or in a different order.

[0036] First, in step S100, the air flow meter 22 detects the flow rate of air taken into the intake passage 20 (intake air volume), and the processor 51 of the control device 50 acquires the intake air volume from the air flow meter 22. When the engine system 100 is operating, the air flow meter 22 constantly measures the intake air volume flowing through the intake passage 20.

[0037] Next, in step S101, the processor 51 determines whether a fire has occurred in the air cleaner 21. The processor 51 determines whether a fire has occurred in the air cleaner 21 based on the intake air volume detected in step S100. Here, the intake air volume measured by the air flow meter 22 changes depending on the opening degree of the throttle valve 23. If a fire occurs in the air cleaner 21, the air cleaner 21 is damaged by the fire, and air inside the air cleaner 21 leaks from the damaged area. As a result, if a fire occurs in the air cleaner 21, the intake air volume measured by the air flow meter 22 increases rapidly. Therefore, the processor 51 determines that a fire has occurred in the air cleaner 21 if the intake air volume measured by the air flow meter 22 increases rapidly. For example, the processor 51 determines that a fire has occurred in the air cleaner 21 if the difference between the currently acquired intake air volume and the most recently acquired intake air volume is equal to or greater than a predetermined value. Here, the predetermined value is set based on the relationship between the opening degree of the throttle valve 23 and the intake air volume measured by the air flow meter 22. For example, the relationship between the opening of the throttle valve 23 and the intake air amount measured by the air flow meter 22 is obtained in advance by testing, simulation, etc. Specifically, for example, the difference between the maximum intake air amount and the minimum intake air amount in the engine system 100 is set as the predetermined value. Then, the predetermined value is recorded in advance in the secondary memory 53 of the control device 50, etc.

[0038] If it is determined that a fire has occurred in the air cleaner 21 (YES in step S101), the process proceeds to step S102. However, if it is determined that a fire has not occurred in the air cleaner 21 (NO in step S101), the process returns to step S100.

[0039] Next, in step S102, processor 51 instructs the driver to stop the vehicle. The instruction to the driver may be notified by, for example, an image or sound. For example, processor 51 may instruct the driver to stop the vehicle by displaying, on a display unit provided in the vehicle, a display image indicating that a fire has occurred in air cleaner 21 and instructing the driver to stop the vehicle in a safe place. Processor 51 may also instruct the driver to stop the vehicle by outputting, from a speaker provided in the vehicle, a sound indicating that a fire has occurred in air cleaner 21 and instructing the driver to stop the vehicle in a safe place.

[0040] Next, in step S103, the processor 51 determines whether the vehicle has stopped. Here, the method by which the processor 51 determines whether the vehicle has stopped is not particularly limited. For example, in the present embodiment, as an example, when a speed sensor provided in the vehicle indicates that the vehicle speed is 0 km / h, the processor 51 determines that the vehicle has stopped.

[0041] If it is determined that the vehicle has stopped (YES in step S103), the process proceeds to step S104. If it is determined that the vehicle has not stopped (NO in step S103), the process returns to step S102.

[0042] Next, in step S104, the processor 51 closes at least one of the throttle valve 23 and the EGR valve 42. In this embodiment, as an example, a case will be described in which the processor 51 closes the throttle valve 23 and the EGR valve 42. When the throttle valve 23 is closed, the intake passage 20 and the engine 10 are blocked, and therefore the supply of intake air to the engine 10 is stopped. Accordingly, the intake of new air into the intake passage 20 is also stopped, and the spread of a fire in the air cleaner 21 can be suppressed. Note that, if the throttle valve 23 and the EGR valve 42 are already closed when it is determined in step S103 that the vehicle has stopped, step S104 may be omitted.

[0043] Next, in step S105, processor 51 closes exhaust valve 34 (opening degree 0%). This prevents exhaust gas from passing through muffler 35 and being discharged outside the vehicle, and the exhaust gas is stored in exhaust flow path 30. In addition, EGR valve 42 and exhaust valve 34 are closed, and the pressure of exhaust gas present in the portion of EGR flow path 40 upstream of EGR valve 42 and in exhaust flow path 30 increases.

[0044] Next, in step S106, the pressure sensor 36 detects the pressure of the exhaust gas in the exhaust flow path 30, and the processor 51 acquires the pressure of the exhaust gas from the pressure sensor 36. For example, the processor 51 acquires, as the pressure of the exhaust gas in the exhaust flow path 30, the pressure of the exhaust gas upstream of the filter 33 (front pressure) or the pressure of the exhaust gas downstream of the filter 33 (rear pressure) measured by the pressure sensor 36, which is a differential pressure sensor.

[0045] Next, in step S107, the processor 51 determines whether a predetermined amount of exhaust gas has accumulated in the exhaust passage 30. The processor 51 determines whether a predetermined amount of exhaust gas has accumulated in the exhaust passage 30 based on the exhaust gas pressure in the exhaust passage 30 detected in S106. Here, the predetermined amount of exhaust gas is the amount of exhaust gas required to cause the exhaust gas to flow back from the exhaust passage 30 to the air cleaner 21. More specifically, the predetermined amount of exhaust gas is the amount of exhaust gas that can flow from the exhaust passage 30 through the EGR passage 40 and the intake passage 20 to the air cleaner 21. For example, the relationship between the exhaust gas pressure detected by the pressure sensor 36 and the amount of exhaust gas accumulated in the exhaust passage 30 is obtained in advance by testing, simulation, or the like. A reference pressure of the exhaust gas corresponding to the predetermined amount of exhaust gas is recorded in advance in the secondary memory 53 of the control device 50, for example. If the pressure of the exhaust gas detected in step S106 is equal to or greater than the reference pressure corresponding to the predetermined amount of exhaust gas, the processor 51 determines that the predetermined amount of exhaust gas is stored in the exhaust flow path 30.

[0046] If it is determined that the predetermined amount of exhaust gas has accumulated in the exhaust flow path 30 (YES in step S107), the process proceeds to step S108. However, if it is determined that the predetermined amount of exhaust gas has not accumulated (NO in step S107), the process returns to step S106.

[0047] Next, in step S108, the processor 51 stops the operation of the engine 10. When the operation of the engine 10 is stopped, exhaust gas is no longer discharged from the combustion chamber 13 of the engine 10. Therefore, if the operation of the engine 10 is stopped before a predetermined amount of exhaust gas is accumulated in the exhaust passage 30, there is a risk that the exhaust gas in the exhaust passage 30 will not reach the air cleaner 21 even if it is caused to flow back toward the intake passage 20. Therefore, it is preferable to stop the operation of the engine 10 after it is determined in step S107 that a predetermined amount of exhaust gas has accumulated in the exhaust passage 30. This allows a sufficient amount of exhaust gas to flow back to the air cleaner 21, thereby reliably extinguishing a fire in the air cleaner 21. On the other hand, as long as a predetermined amount of exhaust gas is accumulated in the exhaust passage 30, the timing of stopping the operation of the engine 10 is not particularly limited. For example, the operation of the engine 10 may be stopped (step S108) simultaneously with the stopping of the vehicle (step S103).

[0048] Next, in step S109, the temperature sensor 37 detects the temperature of the exhaust gas in the exhaust flow path 30, and the processor 51 acquires the temperature of the exhaust gas measured by the temperature sensor 37 as the temperature of the exhaust gas stored in the exhaust flow path 30.

[0049] Next, in step S110, processor 51 determines whether the temperature of the exhaust gas stored in exhaust flow path 30 is equal to or lower than a predetermined temperature. Processor 51 determines whether the temperature of the exhaust gas in exhaust flow path 30 detected in S109 is equal to or lower than a predetermined temperature. Here, the predetermined temperature is a temperature at which the exhaust gas in exhaust flow path 30 does not melt or damage components constituting the reverse flow path from exhaust flow path 30 through EGR flow path 40 and intake flow path 20 to air cleaner 21 due to the heat of the exhaust gas flowing backward. Specifically, the predetermined temperature is, for example, 200°C to 300°C. This prevents damage to components provided in the reverse flow path when exhaust gas is caused to flow backward from exhaust flow path 30 to air cleaner 21. Furthermore, if the temperature of the reverse flow exhaust gas is lower than the predetermined temperature, the heat of the reverse flow exhaust gas does not exacerbate a fire in air cleaner 21, thereby facilitating the extinguishing of the fire.

[0050] If it is determined that the temperature of the exhaust gas stored in the exhaust flow path 30 is equal to or lower than the predetermined temperature (YES in step S110), the process proceeds to step S111. However, if it is determined that the temperature of the exhaust gas in the exhaust flow path 30 is not equal to or lower than the predetermined temperature (NO in step S110), the process returns to step S109.

[0051] Next, in step S111, the processor 51 opens the throttle valve 23 and the EGR valve 42 while keeping the exhaust valve 34 closed. This allows the exhaust gas stored in the exhaust flow path 30 from the upstream side of the EGR valve 42, in an amount equal to or greater than the predetermined amount, to flow back to the air cleaner 21 through the EGR flow path 40 and the intake flow path 20.

[0052] Next, in step S112, the fire in the air cleaner 21 is extinguished by the exhaust gas flowing back from the exhaust passage 30. The exhaust gas stored in the exhaust passage 30 contains carbon monoxide (CO), nitrogen oxides (NO X It is a low-oxygen gas containing oxygen (CO₂) and carbon dioxide (CO₂), etc. Therefore, by causing the exhaust gas to flow back into the air cleaner 21, it is possible to extinguish a fire.

[0053] (effect) The effects of the engine system 100 according to the first embodiment will be described.

[0054] In the engine system 100 according to the first embodiment, the control device 50 determines whether a fire has occurred in the air cleaner 21 based on the intake air volume detected by the air flow meter 22. If it determines that a fire has occurred, the control device 50 closes the exhaust valve 34 and a valve that can block or connect the intake flow path 20 and the exhaust flow path 30 to store exhaust gas in the exhaust flow path 30, and then opens the valve to cause the exhaust gas stored in the exhaust flow path 30 to flow back through the intake flow path 20 to the air cleaner 21. This allows for early detection of a fire in the air cleaner 21 and for the fire to be extinguished promptly. This minimizes damage to the vehicle caused by the fire.

[0055] Furthermore, the engine system 100 further includes a pressure sensor 36 provided in the exhaust flow path 30 to detect the pressure of the exhaust gas in the exhaust flow path 30, and the control device 50 determines, based on the exhaust gas pressure detected by the pressure sensor 36, whether a predetermined amount of exhaust gas necessary for backflowing to the air cleaner 21 has accumulated in the exhaust flow path 30, and if it determines that the predetermined amount of exhaust gas has accumulated in the exhaust flow path 30, it is preferable to open a valve that is provided to block or connect the intake flow path and the exhaust flow path, thereby causing the exhaust gas accumulated in the exhaust flow path 30 to backflow to the air cleaner 21 through the intake flow path 20. In this way, the exhaust gas necessary to extinguish a fire in the air cleaner 21 is accumulated in the exhaust flow path 30 before the exhaust gas is backflowed, thereby more reliably extinguishing a fire in the air cleaner 21.

[0056] Furthermore, the engine system 100 further includes a temperature sensor 37 provided in the exhaust flow path 30 to detect the temperature of the exhaust gas in the exhaust flow path 30. The control device 50 determines whether the temperature of the exhaust gas detected by the temperature sensor 37 is equal to or lower than a predetermined temperature. If it determines that the temperature of the exhaust gas is equal to or lower than the predetermined temperature, the control device 50 preferably opens a valve that can block or connect the intake flow path and the exhaust flow path, thereby causing the exhaust gas stored in the exhaust flow path 30 to flow back through the intake flow path 20 to the air cleaner 21. This prevents damage to components provided in the backflow path when the exhaust gas is allowed to flow back to the air cleaner 21. Furthermore, if the backflowed exhaust gas is at a low temperature equal to or lower than the predetermined temperature, the heat of the backflowed exhaust gas does not exacerbate a fire in the air cleaner 21, thereby facilitating the extinguishing of the fire.

[0057] In addition, the engine system 100 further includes a first EGR flow path (e.g., EGR flow path 40) that connects the intake flow path 20 and the exhaust flow path 30, and the valve that is arranged to block or connect the intake flow path and the exhaust flow path includes either a first EGR valve (e.g., EGR valve 42) arranged in the first EGR flow path or a throttle valve 23 arranged in the intake flow path 20, or both.When the control device 50 determines that a fire has occurred in the air cleaner 21, it is preferable that the control device 50 closes the exhaust valve 34 and at least one of the first EGR valve or the throttle valve 23 to store exhaust gas in the exhaust flow path 30, and then opens both the throttle valve 23 and the first EGR valve to cause the exhaust gas stored in the exhaust flow path 30 to flow back to the air cleaner 21 through the first EGR flow path and the intake flow path 20. As a result, even when the engine 10 is not in a valve overlap state, the exhaust gas can be made to flow backward through the first EGR passage to extinguish a fire in the air cleaner 21. Therefore, the control device 50 does not need to control the intake and exhaust valves of the engine 10 to a valve overlap state in order to extinguish a fire in the air cleaner 21 by the backward flow of exhaust gas.

[0058] Second Embodiment An engine system 200 according to a second embodiment of the present invention will be described below with reference to Figures 4 and 5. For ease of explanation, members having the same functions as those described in the first embodiment will be denoted by the same reference numerals, and their description will not be repeated.

[0059] (Configuration of engine system 200) An engine system 200 according to the second embodiment will be described with reference to Fig. 4. Fig. 4 is a schematic diagram showing the general configuration of the engine system 200.

[0060] As shown in FIG. 4, the engine system 200 according to the second embodiment includes an engine 10, an intake passage 20, an exhaust passage 30, an EGR passage 40, a control device 50, and an EGR passage 60.

[0061] As described above, the engine system 200 according to the second embodiment differs from the engine system 100 according to the first embodiment (see FIG. 1 ) in that it further includes an EGR flow path 60, an EGR cooler 61, and an EGR valve 62. The EGR flow path 60 is an example of a second EGR flow path. Hereinafter, the EGR flow path 40 (first EGR flow path) and the EGR flow path 60 (second EGR flow path) will be described separately based on the pressure of the exhaust gas flowing therethrough. Specifically, the EGR flow path 40 through which exhaust gas with a higher pressure than the EGR flow path 60 flows will be referred to as an HP-EGR (High Pressure Loop Exhaust Gas Recirculation) flow path 40. The EGR flow path 60 through which exhaust gas with a lower pressure than the EGR flow path 40 flows will be referred to as an LP-EGR (Low Pressure Loop Exhaust Gas Recirculation) flow path 60.

[0062] Furthermore, the EGR cooler 41 and the EGR valve 42 provided in the HP-EGR flow path 40 (first EGR flow path) will be referred to as the HP-EGR cooler 41 and the HP-EGR valve 42, respectively. The EGR cooler 61 and the EGR valve 62 provided in the LP-EGR flow path 60 (second EGR flow path) will be referred to as the LP-EGR cooler 61 and the LP-EGR valve 62, respectively. The LP-EGR valve 62 is an example of a second EGR valve.

[0063] The LP-EGR passage 60 is a recirculation passage connecting the intake passage 20 and the exhaust passage 30. The LP-EGR passage 60 is a passage for recirculating exhaust gas, directly bypassing the intake passage 20 and the exhaust passage 30 without passing through the combustion chamber 13 of the engine 10. In the engine system 200, exhaust gas discharged from the combustion chamber 13 of the engine 10 is recirculated from the exhaust passage 30 to the intake passage 20 via the HP-EGR passage 40, and also from the exhaust passage 30 to the intake passage 20 via the LP-EGR passage 60. For example, one end of the LP-EGR passage 60 is connected to the intake passage 20 between the air cleaner 21 and the air flow meter 22 and the throttle valve 23. The other end of the LP-EGR passage 60 is connected to the exhaust passage 30 between the purification device 31 and the exhaust valve 34. Hereinafter, in the LP-EGR passage 60, the exhaust passage 30 side will be referred to as the upstream side, and the intake passage 20 side will be referred to as the downstream side.

[0064] An LP-EGR cooler 61 is also provided in the LP-EGR passage 60. The LP-EGR cooler 61 cools the exhaust gas that is recirculated from the exhaust passage 30 to the intake passage 20. An LP-EGR valve 62 is provided in the LP-EGR passage 60 downstream of the LP-EGR cooler 61. The LP-EGR valve 62 controls the recirculation of exhaust gas from the exhaust passage 30 to the intake passage 20. The recirculation of exhaust gas from the exhaust passage 30 to the intake passage 20 is controlled according to the opening degree of the LP-EGR valve 62. For example, when the LP-EGR valve 62 is closed (opening degree is 0%), the LP-EGR passage 60 is blocked, and the exhaust gas in the exhaust passage 30 does not pass through the LP-EGR passage 60 and recirculate to the intake passage 20. When the LP-EGR valve 62 is open (opening degree is greater than 0%), the exhaust passage 30, the LP-EGR passage 60, and the intake passage 20 are connected, and the exhaust gas in the exhaust passage 30 passes through the LP-EGR passage 60 and is returned to the intake passage 20.

[0065] In the engine system 200, the processor 51 of the control device 50 executes each process included in the fire extinguishing process S2 described below, instead of the fire extinguishing process S1 described above.

[0066] (Operation of engine system 200) The operation of the engine system 200 according to the second embodiment will be described with reference to Fig. 5. Fig. 5 is a flowchart showing the fire extinguishing process S2 executed by the engine system 200.

[0067] Fire extinguishing process S2 includes steps S200 to S212, as shown in Fig. 5. Steps S200 to S203, S205 to S210, and S212 correspond to steps S100 to S103, S105 to S110, and S111 of fire extinguishing process S1 described above. Therefore, the following describes steps S204 and S211, which are executed instead of steps S104, S111, and S112.

[0068] Step S204 is executed when it is determined that the vehicle has stopped (YES in step S203). In step S204, processor 51 closes throttle valve 23 and LP-EGR valve 62. As in step S104 of fire extinguishing process S1, when throttle valve 23 is closed, the intake passage 20 and engine 10 are blocked, and therefore the supply of intake air to engine 10 is stopped. Accordingly, the intake of new air into intake passage 20 is also stopped, and therefore the spread of fire in air cleaner 21 can be suppressed. Note that, when it is determined in step S203 that the vehicle has stopped, if throttle valve 23 and LP-EGR valve 62 are already closed, step S204 may be omitted.

[0069] Step S211 is executed when it is determined that the temperature of the exhaust gas stored in the exhaust flow path 30 is equal to or lower than a predetermined temperature (YES in step S210). In step S211, the processor 51 opens the LP-EGR valve 62 while keeping the exhaust valve 34 closed. This allows the exhaust gas stored in the exhaust flow path 30 from the upstream side of the LP-EGR valve 62 to flow back to the air cleaner 21 through the LP-EGR flow path 60 and the intake flow path 20.

[0070] (effect) The following describes the effects of the engine system 200 according to the second embodiment. In addition to the effects according to the first embodiment described above, the second embodiment further has the following effects.

[0071] The engine system 200 according to the second embodiment further includes a first EGR flow path (e.g., HP-EGR flow path 40) that connects the intake flow path 20 and the exhaust flow path 30, and a second EGR flow path (e.g., LP-EGR flow path 60) that connects the intake flow path 20 and the exhaust flow path 30 and recirculates exhaust gas at a lower pressure than that of the first EGR flow path from the exhaust flow path 30 to the intake flow path 20. The valve that can block or connect the intake flow path 20 and the exhaust flow path 30 includes a second EGR valve (e.g., LP-EGR valve 62) that is provided in the second EGR flow path. When the control device 50 determines that a fire has occurred in the air cleaner 21, it is preferable that the control device 50 closes the exhaust valve 34 and the second EGR valve to store the exhaust gas in the exhaust flow path 30, and then opens the second EGR valve to cause the exhaust gas stored in the exhaust flow path 30 to flow back to the air cleaner 21 through the second EGR flow path. As a result, if the reverse flow path through the second EGR flow path is shorter in distance to the air cleaner 21 than the reverse flow path through the first EGR flow path, a fire in the air cleaner 21 due to the reverse flow of exhaust gas can be extinguished more quickly.

[0072] Third Embodiment An engine system 300 according to a third embodiment of the present invention will be described below with reference to Figures 6 and 7. For ease of explanation, members having the same functions as those described in the first embodiment will be denoted by the same reference numerals, and their description will not be repeated.

[0073] (Configuration of engine system 300) An engine system 300 according to the third embodiment will be described with reference to Fig. 6. Fig. 6 is a schematic diagram showing the general configuration of the engine system 300.

[0074] As shown in FIG. 6, the engine system 200 according to the third embodiment includes an engine 10, an intake passage 20, an exhaust passage 30, and a control device 50, but does not include an EGR passage 40, an EGR passage 60, etc.

[0075] As such, the engine system 300 according to the third embodiment differs from the engine system 100 according to the first embodiment described above (see FIG. 2) in that it does not include an EGR flow path 40, an EGR cooler 41, and an EGR valve 42.

[0076] In the third embodiment, the EGR flow path 40 is not provided, and therefore, unlike the first embodiment, exhaust gas in the exhaust flow path 30 cannot be caused to flow back to the air cleaner 21 through the EGR flow path 40. Therefore, in the third embodiment, exhaust gas in the exhaust flow path 30 is caused to flow back to the air cleaner 21 through the combustion chamber 13 of the cylinder 11 of the engine 10. For this reason, during this backflow, the control device 50 controls the various valves in the combustion chamber 13 of the engine 10 to a valve overlap state and then stops the operation of the engine 10. As a result, exhaust gas stored in the exhaust flow path 30 can be caused to flow back to the air cleaner 21 through the exhaust port 18, combustion chamber 13, and intake port 17 of the engine 10, and the intake flow path 20.

[0077] In the engine system 300, the processor 51 of the control device 50 executes each process included in the fire extinguishing process S3 described next, instead of the fire extinguishing process S1 according to the first embodiment described above.

[0078] (Operation of engine system 300) The operation of the engine system 300 will be described with reference to Fig. 7. Fig. 7 is a flowchart showing the fire extinguishing process S3 executed by the engine system 300.

[0079] 7, the fire extinguishing process S3 includes steps S300 to S312. Steps S300 to S303, S305 to S307, S309 to S310, and S312 correspond to steps S100 to S103, S105 to S107, S109 to S110, and S112 of the fire extinguishing process S1 described above. Therefore, the following describes steps S304, S308, and S311, which are executed instead of steps S104, S108, and S111.

[0080] Step S304 is executed when it is determined that the vehicle has stopped (YES in step S303). In step S304, the processor 51 closes the throttle valve 23. As in step S104 of the fire extinguishing process S1, when the throttle valve 23 is closed, the intake air flow path 20 and the engine 10 are blocked, and the supply of intake air to the engine 10 is stopped. Accordingly, the intake of new air into the intake air flow path 20 is also stopped, and the spread of fire in the air cleaner 21 can be suppressed. Note that, when it is determined in step S203 that the vehicle has stopped, if the throttle valve 23 is already closed, step S304 may be omitted.

[0081] Step S308 is executed when it is determined that a predetermined amount of exhaust gas has accumulated in the exhaust flow path 30 (YES in step S307). In step S308, processor 51 stops the operation of engine 10 with the intake valve of intake port 17 and the exhaust valve of exhaust port 18 open (so-called valve overlap state). This allows intake flow path 20 and exhaust flow path 30 to communicate with each other via cylinder 11 in which intake port 17 and exhaust port 18 are formed.

[0082] Step S311 is executed when it is determined that the temperature of the exhaust gas stored in the exhaust flow path 30 is equal to or lower than a predetermined temperature (YES in step S310). In step S311, the processor 51 opens the throttle valve 23 while keeping the exhaust valve 34 closed. This allows the exhaust gas stored in the exhaust flow path 30 to flow back to the air cleaner 21 through the cylinder 11 of the engine 10 and the intake flow path 20.

[0083] (effect) The following describes the effects of the engine system 300 according to the third embodiment. In addition to the effects according to the first embodiment described above, the third embodiment further has the following effects.

[0084] In the engine system 300 according to the third embodiment, when the control device 50 determines that a fire has broken out in the air cleaner 21, it preferably closes the exhaust valve 34 to store the exhaust gas in the exhaust passage 30, then stops the engine with the intake valve and exhaust valve provided in the intake port 17 and the exhaust port 18 formed in the cylinder 11, respectively, open, and opens the throttle valve 23 to cause the exhaust gas stored in the exhaust passage 30 to flow back through the cylinder 11 and the intake passage 20 of the engine 10 to the air cleaner 21. As a result, even in an engine system 300 that does not have a return passage (e.g., the EGR passage 40 according to the first embodiment or the EGR passage 60 according to the second embodiment) that returns the exhaust gas from the exhaust passage 30 to the intake passage 20, it is possible to extinguish the fire in the air cleaner 21 by causing the exhaust gas in the exhaust passage 30 to flow back through the cylinder 11 to the air cleaner 21.

[0085] [Additional Notes] While the present invention has been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to such embodiments. It is clear that those skilled in the art can conceive of various modifications and alterations within the scope of the claims, and it is understood that such modifications and alterations also fall within the technical scope of the present invention.

[0086] For example, the processes described herein using flowcharts do not necessarily have to be performed in the order shown in the flowcharts. Also, additional processing steps may be employed, or some processing steps may be omitted. Furthermore, the above embodiments may be combined as appropriate. [Explanation of symbols]

[0087] 10 Engine 11 cylinders 12 pistons 13 Combustion chamber 14 Connecting rod 15 crankshaft 16 Crankcase 17 Intake port 18 Exhaust port 20 intake passage 20a intake manifold 21 Air cleaner 22 Air flow meter 23 Throttle valve 30 Exhaust flow path 30a exhaust manifold 31 Purification equipment 32 Catalyst 33 Filters 34 Exhaust valve 35 Muffler 36 Pressure Sensor 37 Temperature Sensor 40 EGR passage, HP-EGR passage 41 EGR cooler, HP-EGR cooler 42 EGR valve, HP-EGR valve 50 Control device 51 processors 52 Primary Memory 53 Secondary Memory 54 Communication Interface 55 Programs 60 EGR passage, LP-EGR passage 61 EGR cooler, LP-EGR cooler 62 EGR valve, LP-EGR valve 100, 200, 300 engine systems

Claims

1. The engine and an intake passage connected to the engine; an exhaust flow path connected to the engine; an air cleaner provided at an intake port of the intake flow path; an air flow meter provided in the intake passage downstream of the air cleaner; an exhaust valve provided in the exhaust flow path; a valve that is provided so as to be able to block or connect the intake passage and the exhaust passage; a control device for controlling the exhaust valve and the opening and closing of the valve; Equipped with The control device determining whether or not a fire has occurred in the air cleaner based on the intake air volume detected by the air flow meter; When it is determined that a fire has occurred, the exhaust valve and the valve are closed to store the exhaust gas in the exhaust flow path, and then the valve is opened to cause the exhaust gas stored in the exhaust flow path to flow back to the air cleaner through the intake flow path. Engine system.

2. a pressure sensor provided in the exhaust passage for detecting the pressure of the exhaust gas in the exhaust passage; The control device determining whether a predetermined amount of the exhaust gas necessary to flow back to the air cleaner has accumulated in the exhaust flow path based on the pressure of the exhaust gas detected by the pressure sensor; when it is determined that the predetermined amount of exhaust gas has accumulated in the exhaust flow path, the valve is opened to cause the exhaust gas accumulated in the exhaust flow path to flow back to the air cleaner through the intake flow path. The engine system of claim 1 .

3. a temperature sensor provided in the exhaust flow path to detect the temperature of the exhaust gas in the exhaust flow path; The control device determining whether the temperature of the exhaust gas detected by the temperature sensor is equal to or lower than a predetermined temperature; When it is determined that the temperature of the exhaust gas is equal to or lower than the predetermined temperature, the valve is opened to cause the exhaust gas stored in the exhaust flow path to flow back to the air cleaner through the intake flow path.

3. The engine system according to claim 1 or 2.

4. a first EGR passage connecting the intake passage and the exhaust passage; the valve includes either or both of a first EGR valve provided in the first EGR flow path and a throttle valve provided in the intake flow path, The control device when it is determined that a fire has occurred, the exhaust valve is closed and at least one of the first EGR valve and the throttle valve is closed to store the exhaust gas in the exhaust passage, and then both the throttle valve and the first EGR valve are opened to cause the exhaust gas stored in the exhaust passage to flow back to the air cleaner through the first EGR passage and the intake passage; 3. The engine system according to claim 1 or 2.

5. a first EGR passage connecting the intake passage and the exhaust passage; a second EGR passage connecting the intake passage and the exhaust passage and allowing the exhaust gas having a lower pressure than the first EGR passage to flow back from the exhaust passage to the intake passage; Further provided with the valve includes a second EGR valve provided in the second EGR flow path, The control device When it is determined that a fire has occurred, the exhaust valve and the second EGR valve are closed to store the exhaust gas in the exhaust flow path, and then the second EGR valve is opened to cause the exhaust gas stored in the exhaust flow path to flow back to the air cleaner through the second EGR flow path.

3. The engine system according to claim 1 or 2.

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