Cooling device

Abstract

To provide a cooling device capable of suppressing heat damage after stopping of a vehicle.SOLUTION: A cooling device includes a regeneration control section for regenerating a filter for purifying exhaust of an internal combustion engine, a determining section for determining whether heat damage occurs or not after stopping of the internal combustion engine, a fan stored in an engine room together with the internal combustion engine, and a fan control section for controlling the fan. When the regeneration control section regenerates the filter and a prescribed condition is satisfied, the determining section determines occurrence of the heat damage, and the fan control section drives the fan when the determining section determines the occurrence of the heat damage.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a cooling device. [Background technology]

[0002] An internal combustion engine generates heat during operation. When the vehicle is running, air flows into the engine compartment from the opening in the front grille, thereby cooling the internal combustion engine and its components (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2016-109114 A Summary of the Invention [Problem to be solved by the invention]

[0004] A filter that purifies the exhaust gas from the internal combustion engine is installed in the exhaust path. The filter collects particulate matter (PM). For example, the temperature of the filter is increased by dither control and ignition retardation, and the PM that has accumulated on the filter is burned to regenerate the filter.

[0005] While the vehicle is running, the components in the engine compartment can be cooled by the wind generated by the vehicle as described above. However, when the vehicle is stopped, it is difficult to cool the components by the wind generated by the vehicle. When the internal combustion engine is stopped after filter regeneration, the components in the engine compartment are exposed to high heat, which may cause heat damage. Therefore, the object of the present invention is to provide a cooling device that can suppress heat damage after the vehicle is stopped. [Means for solving the problem]

[0006] The above object is to provide an engine control system including: a regeneration control unit that regenerates a filter that purifies exhaust gas from an internal combustion engine; a determination unit that determines whether or not heat damage will occur after the internal combustion engine is stopped; a fan that is housed in an engine room together with the internal combustion engine; and a fan control unit that controls the fan; During a period in which the outside air temperature is equal to or higher than a first temperature and the temperature of the filter is equal to or higher than a second temperature, the determination unit continues to increment the determination counter. When the determination counter is equal to or higher than a threshold value, The determination unit determines that the heat damage will occur, and when the determination unit determines that the heat damage will occur, the fan control unit drives the fan, thereby achieving the above-mentioned goal. Effect of the Invention

[0007] It is possible to provide a cooling device that can suppress heat damage after the vehicle is stopped. [Brief description of the drawings]

[0008] [Figure 1] Fig. 1(a) is a schematic diagram illustrating a vehicle according to an embodiment, and Fig. 1(b) is a diagram illustrating an internal combustion engine. [Diagram 2] FIG. 2 is a flowchart illustrating a process executed by the ECU. [Diagram 3] FIG. 3 is a flowchart illustrating a process executed by the ECU. [Figure 4] FIG. 4 is a time chart. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, the cooling device of the present embodiment will be described with reference to the drawings. Fig. 1(a) is a schematic diagram illustrating a vehicle 100 according to the embodiment, and illustrates an engine room 10 with a cover 22 and a cowl louver 24 seen through.

[0010] In Fig. 1(a), the left side is the front side of the vehicle, and the right side is the rear side. The engine room 10 is disposed, for example, at the front of the vehicle. The engine room 10 is covered by a cover 22 and a cowl louver 24. A condenser 14, a radiator 16, a fan 20, and an internal combustion engine 12 are housed in the engine room 10. The condenser 14, the radiator 16, the fan 20, and the internal combustion engine 12 are lined up in this order from the front side of the vehicle.

[0011] An opening 11 is provided at the front of the vehicle (front grill). An engine compartment 10 communicates with the outside of the vehicle through the opening 11. When the vehicle is running, wind (running wind) flows into the engine compartment 10 through the opening 11. When the vehicle stops, the running wind also stops.

[0012] The condenser 14 is a heat exchanger. A refrigerant used in a vehicle air conditioner circulates through the condenser 14. The refrigerant exchanges heat with the air outside the vehicle in the condenser and is cooled.

[0013] The radiator 16 is a heat exchanger, and is located rearward of the vehicle relative to the condenser 14. Coolant circulates inside the radiator 16. The coolant exchanges heat with air outside the vehicle in the radiator 16 and is cooled.

[0014] The fan 20 is an electric fan, and is located rearward of the radiator 16 and forward of the internal combustion engine 12. When the fan 20 is operated, air is sent toward the internal combustion engine 12.

[0015] The internal combustion engine 12 is located rearward of the vehicle relative to the fan 20. For example, the internal combustion engine 12 generates driving force by burning fuel such as gasoline. FIG. 1(b) is a diagram illustrating the internal combustion engine 12. The internal combustion engine 12 is a multi-cylinder engine having, for example, four cylinders. A fuel injection valve 17a and an ignition plug 19a are provided in a cylinder 12a of the internal combustion engine 12. A fuel injection valve 17b and an ignition plug 19b are provided in a cylinder 12b. A fuel injection valve 17c and an ignition plug 19c are provided in a cylinder 12c. A fuel injection valve 17d and an ignition plug 19d are provided in a cylinder 12d.

[0016] Exhaust gas generated by combustion in the internal combustion engine 12 is discharged to the outside of the vehicle through an exhaust path 13. The exhaust path 13 is provided on a portion of the internal combustion engine 12 on the rear side of the vehicle.

[0017] An exhaust purification device 15 is provided in the exhaust path 13. The exhaust purification device 15 includes a filter and a catalyst. The filter is, for example, a GPF (Gasoline Particulate Filter). The catalyst is, for example, a three-way catalyst, and is provided on the inner wall of the filter. The exhaust purification device 15 collects particulate matter (PM) in the exhaust. The catalyst can remove carbon monoxide (CO), nitrogen oxides (NOx), and the like.

[0018] A pressure sensor 25 is provided in the exhaust path 13 upstream of the exhaust purification device 15, and a pressure sensor 26 is provided downstream of the exhaust purification device 15. The pressure sensors 25 and 26 detect the pressure in the exhaust path 13.

[0019] The temperature sensor 27 is provided, for example, outside the engine compartment 10, and measures the temperature outside the vehicle (outside air temperature).

[0020] The ECU 30 is a control device including a calculation device such as a CPU (Central Processing Unit), and storage devices such as a flash memory, a ROM (Read Only Memory), and a RAM (Random Access Memory).

[0021] The ECU 30 acquires the outside air temperature detected by the temperature sensor 27. The ECU 30 estimates the temperature of the exhaust purification device 15 and the temperature near the cowl louver 24 based on, for example, the outside air temperature and the rotation speed of the internal combustion engine 12. The ECU 30 acquires the pressure detected by the pressure sensor 25 and the pressure detected by the pressure sensor 26. The ECU 30 calculates the differential pressure between the upstream side and downstream side of the exhaust purification device 15 by taking the difference between these pressures.

[0022] The ECU 30 functions as a regeneration control unit that regenerates the filter of the exhaust purification device 15. For example, when the differential pressure is equal to or greater than a predetermined value, the ECU 30 regenerates the filter. Specifically, the filter regeneration is performed by dither control of the internal combustion engine 12 and control of the ignition timing. In the dither control, the amount of fuel supplied from the fuel injection valve is changed to make the air-fuel ratio different between the cylinders of the internal combustion engine 12. The air-fuel ratio of some of the four cylinders becomes leaner than the air-fuel ratio of the other cylinders. By the dither control, more oxygen is sent to the exhaust purification device 15. The ECU 30 can also regenerate the filter by retarding the ignition timing. The temperature of the exhaust purification device 15 is increased to burn the PM accumulated in the filter.

[0023] By increasing the temperature of the exhaust purification device 15 as the filter regeneration, the temperature in the engine room 10 also increases. In particular, the temperature of the exhaust path 13 and the cowl louvers 24 located above the exhaust path 13 is likely to increase. The increase in temperature may damage these components. While the vehicle 100 is running, the wind blows into the engine room 10 from the opening 11. The wind can cool the components, and heat damage can be suppressed. On the other hand, while the vehicle 100 is stopped, the wind does not blow, so cooling by the wind is difficult. The ECU 30 functions as a determination unit that determines whether heat damage will occur, and as a fan control unit that controls the fan 20. By cooling the components with the fan 20 while the vehicle 100 is stopped, heat damage to the components is suppressed.

[0024] 2 and 3 are flowcharts illustrating the processing executed by the ECU 30. As shown in Fig. 2, the ECU 30 acquires the outside air temperature To measured by the temperature sensor 27 (step S10). The ECU 30 estimates the temperature (filter temperature) Tf of the exhaust purification device 15 (step S12). For example, the ECU 30 estimates the filter temperature Tf based on the outside air temperature To, the rotation speed of the internal combustion engine 12, the driving time, the temperature of the cooling water, and the like.

[0025] The ECU 30 determines whether the filter regeneration flag is on (step S14). If the pressure difference between the upstream and downstream sides of the exhaust purification device 15 is less than a predetermined value, the filter regeneration flag is turned off. If the pressure difference is equal to or greater than the predetermined value, the filter regeneration flag is turned on. If the determination in step S14 is negative (No), the ECU 30 does not perform filter regeneration and ends the process. If the determination in step S14 is positive (Yes), the ECU 30 performs filter regeneration (step S16). Specifically, as described above, dither control or the like is performed to increase the temperature of the exhaust purification device 15 and burn PM.

[0026] The ECU 30 determines whether the outside air temperature To is equal to or higher than a threshold value Tth1 (step S18). If the determination is positive, the ECU 30 determines whether the filter temperature Tf is equal to or higher than a threshold value Tth2 (step S20). If the determination is negative in at least one of steps S14, S18, and S20, the ECU 30 ends the process. If the determination is positive in all of steps S14, S18, and S20, the ECU 30 increments a determination counter C as shown in FIG. 3 (step S22).

[0027] The ECU 30 determines whether the determination counter C is equal to or greater than the threshold value Cth (step S24). If the determination is negative, the process ends. If the determination is positive, the ECU 30 determines whether the ignition (IG) is turned off (step S26). If the determination is negative, the process ends. If the determination is positive, the ECU 30 drives the fan 20 (step S28). The fan 20 operates to generate wind to cool components such as the cowl louvers 24 after the vehicle 100 has stopped. This ends the process.

[0028] 4 is a time chart. From the top, the chart shows ignition on / off, outside air temperature To, filter regeneration flag, filter temperature Tf, determination counter C, fan 20 on / off, and temperatures of parts near exhaust path 13. The dashed lines for filter temperature Tf, fan 20, and part temperatures show an example (comparative example) in which fan 20 is not operated. The solid lines for filter temperature Tf, fan 20, and part temperatures show an example (embodiment) in which fan 20 is operated.

[0029] The ignition is turned on and the internal combustion engine 12 starts. In the example of FIG. 4, the outside air temperature To is equal to or higher than Tth1. At time t1, the filter regeneration flag is turned on. As the filter regeneration is executed, the filter temperature Tf increases. At time t2, the filter temperature Tf becomes equal to or higher than Tth2, and at time t3, it becomes lower than Tth2.

[0030] From time t2 to t3, the filter regeneration flag is on, the outside air temperature To is equal to or higher than Tth1, and the filter temperature Tf is equal to or higher than Tth2. The result is Yes in steps S14, S18, and S20 in Fig. 2. As shown in Fig. 4, the determination counter C is incremented and becomes equal to or higher than the threshold value Cth. At time t4, the ignition is turned off and the vehicle 100 stops (dead soak).

[0031] In the comparative example shown by the dashed line in Fig. 4, the fan 20 does not operate. Since the vehicle 100 is stopped, no wind is generated during running. This makes cooling difficult, and the filter temperature Tf and the component temperature rise after the vehicle 100 stops. When the component temperature reaches or exceeds Tth, heat damage may occur to the cowl louvers 24 and the like.

[0032] In the embodiment shown by the solid line in Fig. 4, the fan 20 starts operating at time t4. The fan 20 blows air toward the exhaust path 13, the cowl louvers 24, and other components, thereby cooling the exhaust purification device 15 and the components and suppressing an increase in temperature. The component temperature is lower than Tth, suppressing heat damage.

[0033] According to this embodiment, the ECU 30 regenerates the filter of the exhaust purification device 15. Filter regeneration generates heat from the exhaust purification device 15. The ECU 30 determines whether heat damage will occur after the vehicle 100 is stopped. When the determination counter reaches or exceeds a predetermined value Cth, the ECU 30 determines that heat damage will occur to the parts if the parts are not cooled. The ECU 30 drives the fan 20 after the vehicle 100 is stopped to perform cooling. Cooling can suppress heat damage.

[0034] While the vehicle 100 is traveling, cooling by the traveling wind is possible. On the other hand, when the vehicle 100 is stopped, cooling by the traveling wind is difficult. In this embodiment, if the determination counter C is equal to or greater than the threshold value Cth, the ECU 30 drives the fan 20 after the vehicle 100 is stopped, and cooling is performed by the fan 20. When the vehicle 100 is traveling, cooling is performed by the traveling wind, and when the vehicle is stopped, cooling is performed by the fan 20. Therefore, heat damage can be suppressed both when the vehicle is traveling and when the vehicle is stopped.

[0035] For example, the ECU 30 resets the determination counter C after the vehicle 100 stops, and when the vehicle 100 resumes traveling, the ECU 30 increments the determination counter C from 0. The determination counter C is incremented when the filter regeneration flag is on, the outside air temperature To is equal to or higher than Tth1, and the filter temperature Tf is equal to or higher than Tth2. The condition for incrementing the determination counter C may be changed. For example, the condition may be that the filter regeneration flag is on, and either the outside air temperature To is equal to or higher than Tth1 or the filter temperature Tf is equal to or higher than Tth2. In addition to the outside air temperature and the filter temperature, for example, the temperature of an exhaust system component may be compared with a threshold temperature.

[0036] The drive time of the fan 20 may be determined, for example, according to the value of the judgment counter C. The larger the judgment counter C, the higher the possibility of heat damage occurring, so the drive time of the fan 20 is made longer. The smaller the judgment counter C, the shorter the drive time of the fan 20 is made.

[0037] The threshold value Tth1 for the outside air temperature To, the threshold value Tth2 for the filter temperature Tf, and the threshold value Cth for the determination counter C can be changed. For example, the threshold values ​​Tth1, Tth2, and Cth are set lower when the dealer inspects the vehicle 100 compared to the threshold values ​​Tth1, Tth2, and Cth when the user is using the vehicle 100. The temperature when the filter regeneration is performed at the dealer may be set higher than the temperature of the filter regeneration during use. By setting the threshold value lower, cooling by the fan 20 is more likely to be performed. In addition, the driving time of the fan 20 can be changed. For example, the driving time of the fan 20 is set longer when the dealer inspects the vehicle 100 compared to the driving time of the fan 20 when the user is using the vehicle 100. It is possible to cool more effectively after the filter regeneration at the dealer.

[0038] Although a preferred embodiment of the present invention has been described in detail above, the present invention is not limited to such a specific embodiment, and various modifications and variations are possible within the scope of the gist of the present invention described in the claims. [Explanation of symbols]

[0039] 10 Engine Room 11 Opening 12 Internal combustion engine 12a, 12b, 12c, 12d cylinders 13 Exhaust passage 14 Capacitor 15 Exhaust purification device 16 Radiator 17a, 17b, 17c, 17d Fuel injector 19a, 19b, 19c, 19d Spark plugs 20 Fans 22 Cover 24 Kaurluba 25, 26 Pressure sensor 27 Temperature Sensor 30 ECU 100 vehicles

Claims

[Claim 1] A regeneration control unit that regenerates a filter that purifies exhaust gas from an internal combustion engine; a determination unit that determines whether or not thermal damage will occur after the internal combustion engine is stopped; a fan accommodated in an engine compartment together with the internal combustion engine; A fan control unit that controls the fan, the regeneration control unit regenerates the filter, and the determination unit continues to increment the determination counter during a period in which the outside air temperature is equal to or higher than a first temperature and the temperature of the filter is equal to or higher than a second temperature; When the determination counter is equal to or greater than a threshold value, the determination unit determines that the heat damage will occur, When the determining unit determines that the heat damage will occur, the fan control unit drives the fan.

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