Vehicle control device, vehicle control method, and storage medium

Abstract

The present application provides a vehicle control device, a vehicle control method, and a storage medium. A first passage of a supply passage of a blow-by gas processing device is connected to a portion of an intake passage that is downstream of a compressor of a supercharger. The first passage has a connection portion to the intake passage. A passage downstream portion is a portion of the first passage between the connection portion and a PCV valve. An excessive cooling determination process determines whether the supply passage is excessively cooled by a running wind of the vehicle based on a running speed of the vehicle. In a case where an outside air temperature of the vehicle is equal to or lower than a determination temperature, it is determined that the PCV valve is closed, and it is determined that the supply passage is excessively cooled, all of which are satisfied, an operation state changing process sets an operation of the internal combustion engine to non-supercharged operation.

Description

TECHNICAL FIELD

[0001] The present application relates to a vehicle control device applied to a vehicle equipped with an internal combustion engine, a vehicle control method, and a storage medium. BACKGROUND

[0002] Japanese Patent Application Publication No. 2019-100203 discloses a control device applied to a vehicle. The vehicle is equipped with an internal combustion engine and an actuator. The actuator operates to generate an airflow to a scavenge target portion of the internal combustion engine.

[0003] The control device operates the actuator in a manner that causes gas to flow to the scavenge target portion when at least one of a specific temperature condition and a specific humidity condition is satisfied after the internal combustion engine is stopped. SUMMARY

[0004] According to one aspect of the present application, a vehicle control device is provided. The vehicle control device is a device applied to a vehicle equipped with an internal combustion engine. In the vehicle control device, the internal combustion engine is equipped with an intake passage, an exhaust passage, a supercharger, and a blow-by gas processing device. The supercharger has a turbine provided to the exhaust passage and a compressor provided to the intake passage. The blow-by gas processing device is equipped with a supply passage that supplies blow-by gas to the intake passage. The supply passage has a first passage connected to a portion of the intake passage that is downstream of the compressor and a second passage connected to a portion of the intake passage that is upstream of the compressor. The blow-by gas processing device has a PCV (Positive Crankcase Ventilation) valve disposed to the first passage.

[0005] The portion of the first passage between the connection portion of the first passage and the intake passage and the PCV valve is a passage downstream portion. The PCV valve closes when the pressure of the passage downstream portion reaches a predetermined pressure or more. The vehicle control device has an execution circuit as an execution device. The operation of the internal combustion engine in which the supercharger pressurizes intake air flowing in the intake passage is supercharged operation. The operation of the internal combustion engine in which the supercharger does not pressurize the intake air is non-supercharged operation. At this time, the execution circuit executes: a closed valve determination process of determining whether the PCV valve is closed; and an excessive cooling determination process of determining whether the supply passage is excessively cooled by running wind based on the running speed of the vehicle. In a case where the outside air temperature of the vehicle is equal to or lower than a determination temperature, it is determined in the closed valve determination process that the PCV valve is closed, and it is determined in the excessive cooling determination process that the supply passage is excessively cooled, the execution circuit executes operation state change processing. The operation state change processing sets the operation of the internal combustion engine to the non-supercharged operation to make the pressure of the passage downstream portion smaller than the prescribed pressure.

[0006] The above structure can reduce the pressure of the passage downstream portion of the first passage by setting the operation of the internal combustion engine to the non-supercharged operation, as compared with a case where the operation is the supercharged operation. That is, by setting the operation of the internal combustion engine to the non-supercharged operation, the pressure of the passage downstream portion can be made smaller than the prescribed pressure. When the pressure of the passage downstream portion is smaller than the prescribed pressure, the PCV valve opens, and therefore blow-by gas is supplied from the first passage to the intake passage. On the other hand, in a case where the operation of the internal combustion engine is the supercharged operation, the pressure of the passage downstream portion reaches the prescribed pressure or more. Then, the PCV valve closes. Thus, the supply of blow-by gas to the supply passage via the first passage is stopped, and therefore blow-by gas is supplied from the second passage to the intake passage.

[0007] In the above-described internal combustion engine, when the supply passage of the blow-by gas processing device is continuously excessively cooled in a state where the PCV valve is closed, moisture can freeze in the supply passage. The second passage among the first passage and the second passage is provided at a position farther from the cylinder of the internal combustion engine than the first passage, and thus the second passage is more likely to be affected by the running wind than the first passage. Therefore, in a case where the second passage is excessively cooled, the amount of cooling of the second passage by the running wind is likely to be more than the amount of heating of the second passage by the flow of the blow-by gas in the second passage. In this way, when the amount of cooling is more than the amount of heating, the moisture contained in the blow-by gas can freeze in the second passage. Therefore, in order to prevent the moisture from freezing in the second passage, it is preferable that the blow-by gas not flow in the second passage. On the other hand, the first passage is less likely to be affected by the running wind than the second passage. Therefore, the amount of heating of the first passage by the flow of the blow-by gas in the first passage can be made more than the amount of cooling of the first passage by the running wind. Therefore, in order to prevent the moisture from freezing in the first passage, it is preferable that the blow-by gas flow.

[0008] Therefore, in the above-described vehicle control device, in a case where (i) the outside air temperature of the vehicle is below the determination temperature, (ii) it is determined that the PCV valve is closed, and (iii) it is determined that the supply passage is excessively cooled, the operation state change processing is executed. The operation state change processing sets the operation of the internal combustion engine to the non-supercharging operation, and thus makes the pressure of the passage downstream portion of the first passage lower than the prescribed pressure. As a result, the PCV valve is opened. Thereby, the blow-by gas is caused to flow in the first passage, and on the other hand, the blow-by gas is caused not to flow in the second passage. Thereby, since the first passage is heated by the blow-by gas flowing in the first passage, it is possible to suppress the moisture from freezing in the first passage. On the other hand, since the blow-by gas does not flow in the second passage, it is possible to suppress the moisture contained in the blow-by gas from freezing in the second passage.

[0009] Therefore, the above-described vehicle control device can suppress the moisture from freezing in the supply passage of the blow-by gas processing device in the running of the vehicle.

[0010] Further, as the internal combustion engine, there is an internal combustion engine provided with a supercharger and a blow-by gas processing device. The blow-by gas processing device has a supply passage that supplies blow-by gas to an intake passage. In a case where the vehicle is running, the supply passage is cooled by a running wind. The lower the outside air temperature of the vehicle, the more the amount of cooling of the supply passage by the running wind. Therefore, if the vehicle is continuously run in an environment at an extremely low temperature, the supply passage is continuously excessively cooled by the running wind, and thus moisture can freeze in the supply passage. That is, in the running of the vehicle, the supply passage can be clogged by the frozen moisture. The above-described vehicle control device reduces such a possibility.

[0011] In the above-described vehicle control device, the execution circuit determines that the supply passage is excessively cooled in the excessive cooling determination processing when the vehicle speed is equal to or higher than a determination speed.

[0012] The higher the vehicle speed, the more the cooling amount of the supply passage by the running wind is likely to increase. Therefore, the above-described vehicle control device determines that the supply passage is excessively cooled when the vehicle speed is equal to or higher than a determination speed. By executing the operation state changing processing when the vehicle speed is equal to or higher than the determination speed, freezing of the moisture in the supply passage can be suppressed.

[0013] In the above-described vehicle control device, the execution circuit determines whether the supply passage is excessively cooled in the excessive cooling determination processing on the basis of the vehicle speed and an engine speed of the internal combustion engine.

[0014] According to the engine speed, the moisture is likely to freeze in the supply passage even when the vehicle speed is lower than the determination speed. Therefore, in the above-described vehicle control device, whether the supply passage is excessively cooled is determined on the basis of the vehicle speed and the engine speed. Further, when it is determined on the basis of the vehicle speed and the engine speed that the supply passage is excessively cooled, the operation state changing processing is executed. If the current vehicle speed and the engine speed are continuously maintained, the PCV valve is opened by executing the operation state changing processing when the moisture is likely to freeze in the supply passage. Therefore, freezing of the moisture in the supply passage can be suppressed.

[0015] When the vehicle to which the above-described vehicle control device is applied is provided with a transmission device, it is preferable that the operation state changing processing include processing of changing a gear ratio of the transmission device.

[0016] In order to maintain the vehicle speed even when the gear ratio of the transmission device is changed, the engine load factor and the engine speed of the internal combustion engine are changed. When the engine load factor and the engine speed are thus changed, the driving mode of the supercharger is changed, and therefore the pressure of the portion of the intake passage that is located downstream of the compressor changes. That is, the pressure of the passage downstream portion of the first passage changes.

[0017] Therefore, in the above-described vehicle control device, when the operation state changing processing is executed, the gear ratio of the transmission device is changed in such a manner that the pressure of the passage downstream portion is lower than a predetermined pressure. Therefore, by execution of the operation state changing processing, the PCV valve can be opened. Therefore, the vehicle speed can be prevented from changing, and freezing of the moisture in the supply passage can be suppressed.

[0018] In the above-described vehicle control device, the execution circuit alternately repeats the operation state change processing and the recovery processing in a case where the outside air temperature is equal to or lower than the determination temperature, the PCV valve is determined to be closed by the closed valve determination processing, and the supply passage is determined to be excessively cooled by the excessive cooling determination processing. The recovery processing returns the transmission ratio to the transmission ratio before the operation state change processing is started.

[0019] When the operation state change processing is executed, the value of the transmission ratio of the transmission device becomes a value of a low-speed side transmission ratio compared to the value of the transmission ratio selected in a case where the operation state change processing is not executed. Therefore, if the operation state change processing is continuously executed, the transmission ratio of the transmission device does not become a high-speed side transmission ratio, and the driver of the vehicle can feel uncomfortable. On the other hand, even in a case where the above-described three conditions are established, if the PCV valve is not opened, the moisture does not immediately freeze in the supply passage.

[0020] Therefore, in the above-described vehicle control device, the operation state change processing and the recovery processing are alternately repeated. Therefore, even in a case where the above-described three conditions are established, a period in which the transmission ratio of the transmission device becomes a high-speed side transmission ratio can be set. Therefore, the transmission ratio of the transmission device can be made a high-speed side transmission ratio, and freezing of the moisture in the supply passage can be suppressed.

[0021] In the above-described vehicle control device, the execution circuit starts the operation state change processing after a predetermined delay time elapses in a case where the outside air temperature is equal to or lower than the determination temperature, the PCV valve is determined to be closed by the closed valve determination processing, and the supply passage is determined to be excessively cooled by the excessive cooling determination processing.

[0022] In the above-described vehicle control device, during a period from a state in which the above-described three conditions are established to the delay time elapses, the state in which the transmission ratio of the transmission device is a high-speed side transmission ratio can be continued. On the other hand, if the operation state change processing is executed after the delay time elapses, the transmission ratio of the transmission device is changed to a low-speed side transmission ratio compared to the transmission ratio before the operation state change processing is started. Thus, by setting the operation of the internal combustion engine to the non-supercharging operation, the pressure of the passage downstream portion of the first passage can be made smaller than the prescribed pressure. That is, the PCV valve can be opened. Thus, a period in which the transmission ratio of the transmission device is set to a high-speed side transmission ratio can be set, and freezing of the moisture in the supply passage can be suppressed.

[0023] In the above-described vehicle control device, the execution circuit determines that the PCV valve is opened by execution of the operation state change processing when the PCV valve is opened by a change in the operation state of the internal combustion engine during a period in which the operation state change processing is not executed, in a case where the outside air temperature is equal to or lower than the determination temperature, it is determined that the PCV valve is closed by the closed valve determination processing, and it is determined that the supply passage is excessively cooled by the excessive cooling determination processing.

[0024] In the above-described vehicle control device, there is a period in which the operation state change processing is not executed even in a case where the above-described three conditions are all satisfied. In a case where the PCV valve is opened by a change in the operation state of the internal combustion engine during the non-execution period of the operation state change processing, it is determined that the PCV valve is opened by execution of the operation state change processing. Thus, in the vehicle control device in which the operation state change processing and the recovery processing are alternately repeated in a case where the above-described three conditions are all satisfied, the recovery processing can be started early. That is, it is possible to suppress freezing of moisture in the supply passage and to increase the opportunity to make the transmission ratio of the transmission device a high-speed side.

[0025] In the above-described vehicle control device, the execution circuit executes processing of measuring an accumulated time of a state in which the outside air temperature is equal to or lower than the determination temperature, it is determined that the PCV valve is closed by the closed valve determination processing, and it is determined that the supply passage is excessively cooled by the excessive cooling determination processing. The execution circuit executes processing of resetting the accumulated time in a case where the operation state change processing is started. The execution circuit starts the operation state change processing when the accumulated time exceeds a determination accumulated time. The determination accumulated time is set to a time longer than the delay time.

[0026] Depending on the usage method of the vehicle by the driver, the operation state change processing can not be executed even when the above-described accumulated time reaches a certain degree of time. Thus, in the above-described vehicle control device, the operation state change processing is started even when the duration of the state in which the above-described three conditions are all satisfied does not reach the delay time in a case where the accumulated time exceeds the determination accumulated time. Thus, it is possible to suppress freezing of moisture in the supply passage due to non-execution of the operation state change processing.

[0027] However, after the operation state change processing is executed, moisture does not freeze in the supply passage even when the PCV valve is kept closed from the end of the operation state change processing to a certain degree of time. Thus, in the above-described vehicle control device, the accumulated time is reset when the operation state change processing is started.

[0028] In one example of the vehicle control device described above, the execution circuit resets the accumulated time or reduces the accumulated time if at least one of the following conditions is not met: the external temperature is below the determined temperature, the PCV valve is determined to be closed by the valve closure determination process, and the supply passage is determined to be overcooled by the overcooling determination process.

[0029] If at least one of the above three conditions is not met, it is assumed that the moisture will not freeze in the supply path. Therefore, in the above vehicle control device, when at least one of the above three conditions is not met, the accumulated time is reset or reduced. As a result, it is possible to suppress the freezing of moisture in the supply path and to suppress the increase in the frequency of execution of operation state change processing.

[0030] One example of a vehicle using the aforementioned vehicle control device is a hybrid vehicle that also has an electric generator as a power source. In this case, it is preferable that the operating state change processing includes a process that increases the output torque of the electric generator.

[0031] In the aforementioned vehicle control device, the operating state change processing sets the internal combustion engine to non-boosted operation, causing the pressure downstream of the first passage to be lower than a predetermined pressure. Consequently, the output torque of the internal combustion engine decreases, while the output torque of the electric generator increases. That is, the total torque output from the vehicle's power source does not change regardless of whether the operating state change processing is executed. Therefore, it is possible to suppress the decrease in vehicle speed and to prevent moisture from freezing in the supply passage.

[0032] According to other aspects of the present invention, a vehicle control method may also be implemented that performs various processes described in association with any of the various vehicle control devices described above.

[0033] According to other inventions of the present invention, a non-transitory computer-readable recording medium storing programs that cause a processing device to perform various processes associated with any of the aforementioned vehicle control devices can also be realized. Attached Figure Description

[0034] Figure 1 This is a schematic structural diagram of a vehicle equipped with the vehicle control device of the first embodiment.

[0035] Figure 2 It means Figure 1 The diagram shows the operation of the PCV valve in the blow-by treatment device of the vehicle when it is open.

[0036] Figure 3 It means Figure 2 The diagram shows the operation of the PCV valve in the gas leakage treatment device when it is closed.

[0037] Figure 4 It means Figure 1 The graph shows the relationship between the internal combustion engine load rate and the internal combustion engine speed.

[0038] Figure 5 It means based on Figure 1 The diagram shown is a mapping used to determine whether the blow-by gas supply passage is overcooled, based on the vehicle's speed and the internal combustion engine's rotation speed.

[0039] Figure 6 It means by Figure 1 A flowchart of the processing routine executed by the vehicle control device of the first embodiment is shown.

[0040] Figure 7 It means by Figure 1 A flowchart of the processing routine executed by the vehicle control device of the first embodiment is shown.

[0041] Figure 8 This is a flowchart illustrating the processing routine executed by the vehicle control device of the second embodiment.

[0042] Figure 9 This is a schematic structural diagram of a vehicle equipped with the vehicle control device of the third embodiment.

[0043] Figure 10 It means by Figure 9 A flowchart of the processing routine executed by the vehicle control device in the third embodiment. Detailed Implementation

[0044] It should be understood that the phrase "at least one of A and B" in this specification means "A only", "B only", or "both A and B".

[0045] The following is in accordance with Figures 1-7 A first embodiment of the vehicle control device, vehicle control method, and vehicle control processing is described.

[0046] Figure 1 The illustration shows a vehicle 10 using a control device 70 as a vehicle control device. The vehicle 10 includes an internal combustion engine 20, a transmission 12, and drive wheels 14.

[0047] The transmission 12 is positioned midway along the torque transmission path from the internal combustion engine 20 to the drive wheel 14. In this embodiment, the transmission 12 is a stepped transmission. Therefore, when the selected gear of the transmission 12 changes, the gear ratio of the transmission 12 changes. That is, if the selected gear of the transmission 12 changes to a lower-speed gear, the gear ratio of the transmission 12 changes towards the lower speed side.

[0048] <Internal combustion engine>

[0049] The internal combustion engine 20 is provided with a cylinder block 21, a crankcase 22, an oil pan 23, a cylinder head 24, and a cylinder head cover 25.

[0050] The crankcase 22 is installed at a lower portion of the cylinder block 21. A crankshaft 26, which is an output shaft of the internal combustion engine 20, is housed in the crankcase 22. The oil pan 23 is installed at a lower portion of the crankcase 22. In the oil pan 23, oil circulating in the internal combustion engine 20 is stored.

[0051] The cylinder head 24 is installed at an upper portion of the cylinder block 21. A plurality of cylinders 27 are partitioned by the cylinder block 21 and the cylinder head 24. In the present embodiment, only one cylinder 27 is illustrated. The cylinder head cover 25 is installed at an upper portion of the cylinder head 24. Figure 1

[0052] The internal combustion engine 20 is provided with the same number of pistons 28 and connecting rods 29 as the number of the cylinders 27. The pistons 28 are housed in the corresponding cylinders 27, and are linked to the crankshaft 26 via the corresponding connecting rods 29. The crankshaft 26 is rotated by the reciprocating motion of the plurality of pistons 28 in the cylinders 27.

[0053] The internal combustion engine 20 is provided with an intake passage 31 connected to the cylinder head 24. The intake passage 31 is a passage through which intake air flows to be introduced into the plurality of cylinders 27. On the intake passage 31, as indicated by an arrow in the drawing, an electrically driven throttle valve 32 is provided, which adjusts the amount of intake air, i.e., the intake air amount, flowing in the intake passage 31. Moreover, in the plurality of cylinders 27, a mixture of fuel and intake air introduced into the cylinders 27 is combusted. When such a mixture is combusted, exhaust gas is generated in the plurality of cylinders 27. Figure 1

[0054] The internal combustion engine 20 is provided with an exhaust passage 35 connected to the cylinder head 24. From the plurality of cylinders 27, exhaust gas is discharged to the exhaust passage 35. Then, as indicated by an arrow in the drawing, the exhaust gas flows in the exhaust passage 35. Figure 1

[0055] ​​​The internal combustion engine 20 is provided with a supercharger 40 of exhaust gas drive type. The supercharger 40 has a turbine 41 provided in the exhaust passage 35 and a compressor 42 provided in the intake passage 31. The compressor 42 is disposed at a position in the intake passage 31 upstream of the throttle valve 32. Further, the compressor 42 is driven in synchronization with the turbine 41 when the turbine 41 is driven by the flow of exhaust gas flowing in the exhaust passage 35. By thus driving the compressor 42, intake air flowing in the intake passage 31 is pressurized and introduced into the plurality of cylinders 27. When the compressor 42 is thus driven, the pressure of the portion of the intake passage 31 downstream of the throttle valve 32 becomes positive pressure. On the other hand, in the case where the compressor 42 is stopped, the pressure of the portion of the intake passage 31 downstream of the throttle valve 32 becomes negative pressure.

[0056] In the present embodiment, the operation of the internal combustion engine 20 in which intake air is pressurized by the supercharger 40 is referred to as "supercharged operation". On the other hand, the operation of the internal combustion engine 20 in which intake air is not pressurized by the supercharger 40 is referred to as "non-supercharged operation".

[0057] The internal combustion engine 20 is provided with a blow-by gas processing device 50. The blow-by gas processing device 50 has an accumulation chamber 51 and a communication passage 52. The accumulation chamber 51 is partitioned by the cylinder head 24 and the cylinder head cover 25. The accumulation chamber 51 accumulates blow-by gas generated in the internal combustion engine 20. The communication passage 52 is a passage that communicates the crankcase 22 and the accumulation chamber 51. The communication passage 52 is formed across the cylinder block 21 and the cylinder head 24. Therefore, blow-by gas that leaks from the plurality of cylinders 27 into the crankcase 22 flows into the accumulation chamber 51 via the communication passage 52.

[0058] The blow-by gas processing device 50 has a blow-by gas supply passage (54, 55) that supplies blow-by gas accumulated in the accumulation chamber 51 to the intake passage 31 and a PCV valve 53. The blow-by gas supply passage is a passage that connects the accumulation chamber 51 and the intake passage 31 and supplies blow-by gas to the intake passage 31. The blow-by gas processing device 50 has a first passage 54 and a second passage 55 as the blow-by gas supply passage. The first passage 54 is connected to the portion of the intake passage 31 downstream of the compressor 42. Specifically, the first passage 54 is connected to the portion of the intake passage 31 downstream of the throttle valve 32. The second passage 55 is connected to the portion of the intake passage 31 upstream of the compressor 42.

[0059] PCV valve 53 is installed in the first passage 54. The connection between the first passage 54 and the intake passage 31 is designated as the "downstream connection portion," and the portion between the downstream connection portion of the first passage 54 and PCV valve 53 is designated as the "downstream portion 54a of the passage." At this time, PCV valve 53 opens when the pressure in the downstream portion 54a of the passage is less than a specified pressure, and closes when the pressure in the downstream portion 54a of the passage is greater than or equal to the specified pressure. When the internal combustion engine 20 is operating in non-turbo mode, negative pressure is generated in the portion of the intake passage 31 downstream of the throttle valve 32. Since the downstream portion 54a of the passage is connected to the portion of the intake passage 31 downstream of the throttle valve 32, negative pressure is also generated in the downstream portion 54a of the passage. Therefore, since the pressure in the downstream portion 54a of the passage is less than the specified pressure, PCV valve 53 opens when the internal combustion engine 20 is operating in non-turbo mode. During the transition of the internal combustion engine 20 from non-turbo operation to turbo operation, the pressure in the portion of the intake passage 31 downstream of the throttle valve 32 gradually increases. Therefore, the pressure in the downstream section 54a of the intake passage gradually increases. Furthermore, when the pressure in the downstream section 54a reaches or exceeds the specified pressure, the PCV valve 53 closes. Subsequently, when the internal combustion engine 20 operates in turbocharged mode, the pressure in the portion of the intake passage 31 downstream of the throttle valve 32 becomes positive pressure, thus the pressure in the downstream section 54a of the intake passage remains above the specified pressure. That is, when the internal combustion engine 20 operates in turbocharged mode, the PCV valve 53 closes.

[0060] Figure 2 The diagram illustrates the flow of bleed gas when PCV valve 53 is open. Figure 2 In the diagram, the dashed line represents the flow of blow-by gas, and the solid line represents the flow of intake air. When the PCV valve 53 is open, the blow-by gas in the storage chamber 51 is supplied to the intake passage 31 via the first passage 54. On the other hand, a portion of the intake air flows from the intake passage 31 into the second passage 55. Therefore, when the PCV valve 53 is open, the blow-by gas will not flow through the second passage 55.

[0061] Figure 3 The diagram illustrates the flow of bleed gas when PCV valve 53 is closed. Figure 3 In the diagram, the dashed line represents the flow of blow-by gas, and the solid line represents the flow of intake air. When the PCV valve 53 is closed, the flow of gas through the first passage 54 stops. Therefore, the blow-by gas in the storage chamber 51 is supplied to the intake passage 31 via the second passage 55.

[0062] like Figure 1As shown, the internal combustion engine 20 includes a crankshaft angle sensor 61 and an air flow meter 62. The crankshaft angle sensor 61 detects the rotation angle of the crankshaft 26. Furthermore, the crankshaft angle sensor 61 outputs a detection signal corresponding to the rotational speed of the crankshaft 26 to the control device 70. The air flow meter 62 detects the amount of intake air flowing in the intake passage 31, i.e., the intake air volume, and outputs a detection signal corresponding to this detection result to the control device 70.

[0063] <Control Device>

[0064] The control unit 70 controls various actuators of the internal combustion engine 20, namely the throttle valve 32 and the fuel injection valve, based on the detection values ​​of multiple sensors, including the crankshaft angle sensor 61 and the air flow meter 62. Sensors other than the crankshaft angle sensor 61 and the air flow meter 62 include a vehicle speed sensor 64 and an outside temperature sensor 65. The vehicle speed sensor 64 detects the vehicle speed 10. The outside temperature sensor 65 detects the outside temperature of the vehicle 10. Furthermore, in the following description, the rotational speed of the crankshaft 26 based on the detection signal from the crankshaft angle sensor 61 will be designated as "internal combustion engine speed Ne," i.e., internal combustion engine speed. Additionally, the detection value of the air flow meter 62 will be designated as "intake air volume Ga." The detection value of the vehicle speed sensor 64 will be designated as "driving speed SP," and the detection value of the outside temperature sensor 65 will be designated as "outside temperature TMP."

[0065] like Figure 1 As shown, the control device 70 is a control circuit having a CPU 71 and a memory 72. The memory 72 is a storage circuit that executes various control programs executed by the CPU 71. In this embodiment, the CPU 71 corresponds to "execution device" or "execution circuit" or "processing device" or "processing circuit".

[0066] While the vehicle 10 is in motion, the components of the internal combustion engine 20 are cooled by the airflow. For example, in... Figure 2 and Figure 3 As indicated by the hollow arrow, the blow-by supply passages of the blow-by treatment device 50, namely the first passage 54 and the second passage 55, are cooled by the driving air. For example, when the vehicle 10 is being driven in an environment below freezing, the amount of cooling effect of the driving air on the blow-by supply passages (54, 55) is very large. Moreover, when the blow-by supply passages are overcooled, moisture may freeze in the blow-by supply passages.

[0067] Furthermore, in this embodiment, the distance from the connection portion of the second passage 55 to the intake passage 31 to the cylinder block 21 is longer than the distance from the connection portion of the first passage 54 to the intake passage 31 to the cylinder block 21. Therefore, the second passage 55 is more susceptible to the influence of driving wind than the first passage 54.

[0068] In the present embodiment, the CPU 71 executes the operation state changing process in a case where it is determined that water is likely to freeze in at least one of the first passage 54 and the second passage 55, which are blow-by gas supply passages. The "operation state changing process" is a process of opening the PCV valve 53 by controlling the gear ratio of the transmission 12 and the operation of the internal combustion engine 20 so that the pressure of the passage downstream portion 54a is less than a prescribed pressure.

[0069] Referring to Figure 4 The operation state changing process of the present embodiment will be described. In Figure 4 , the solid line is an equal torque line of the output torque of the internal combustion engine 20. In addition, in the internal combustion engine load factor KL of Figure 4 , the area in which the internal combustion engine load factor KL is higher than the horizontally extending dashed line is an area in which the operation of the internal combustion engine 20 becomes supercharged operation. In the area in which the internal combustion engine load factor KL is lower than the dashed line, the operation of the internal combustion engine 20 becomes non-supercharged operation.

[0070] In the operation state changing process, the CPU 71 controls the operation of the internal combustion engine 20 and the gear ratio of the transmission 12 so as to satisfy the following conditions (C1) and (C2). In addition, the internal combustion engine load factor KL is a value based on the intake air amount Ga and the internal combustion engine speed Ne. The more the intake air amount Ga, the higher the internal combustion engine load factor KL.

[0071] Condition (C1): The gear stage selected by the transmission 12 in the case where the operation state changing process is executed is set to a lower speed side gear stage compared to the gear stage selected by the transmission 12 in the case where the operation state changing process is not executed.

[0072] Condition (C2): The output torque of the internal combustion engine 20 is maintained while the internal combustion engine load factor KL is reduced until the pressure of the passage downstream portion 54a of the first passage 54 is less than a prescribed pressure.

[0073] When the pressure of the passage downstream portion 54a is less than the prescribed pressure by the execution of such an operation state changing process by the CPU 71, the PCV valve 53 opens.

[0074] Process of determining the possibility of water freezing in the blow-by gas supply passage

[0075] Referring to Figure 6 The process routine of determining the possibility of water freezing in the blow-by gas supply passage will be described. This process routine is repeatedly executed by the CPU 71 by a control program, and is repeatedly executed in each predetermined control cycle.

[0076] In the present processing routine, in step Sll, the CPU 71 determines whether or not the outside air temperature TMP of the vehicle 10 is below a determination temperature TMPth. As a criterion for determining whether or not the vehicle 10 is traveling in an environment at or below the freezing point, the determination temperature TMPth is set, for example. In the case where the outside air temperature TMP is higher than the determination temperature TMPth, it is considered that moisture will not freeze in the blow-by gas supply passage. In contrast, in the case where the outside air temperature TMP is below the determination temperature TMPth, it is considered that moisture can freeze in the blow-by gas supply passage during travel of the vehicle 10. In the case where the outside air temperature TMP is higher than the determination temperature TMPth (Sll: NO), the CPU 71 causes the processing to proceed to step S19. On the other hand, in the case where the outside air temperature TMP is below the determination temperature TMPth (Sll: YES), the CPU 71 causes the processing to proceed to step S13.

[0077] In step S13, the CPU 71 determines whether or not the PCV valve 53 is closed. As described above, the passage downstream portion 54a of the first passage 54 is connected to a portion of the intake passage 31 that is more downstream than the throttle valve 32. Therefore, it is considered that the pressure of the portion of the intake passage 31 that is more downstream than the throttle valve 32 and the pressure of the passage downstream portion 54a are equal to each other. Therefore, the CPU 71 estimates the pressure of the portion of the intake passage 31 that is more downstream than the throttle valve 32 on the basis of the throttle opening, which is the opening degree of the throttle valve 32, the intake air amount Ga, and the like. Then, the CPU 71 determines that the PCV valve 53 is closed in the case where the estimated value of the pressure is equal to or higher than a prescribed pressure, and determines that the PCV valve 53 is not closed in the case where the estimated value of the pressure is lower than the prescribed pressure. That is, step S13 corresponds to "closed valve determination processing" of determining whether or not the PCV valve 53 is closed. In the case where it is determined that the PCV valve 53 is not closed (S13: NO), the CPU 71 causes the processing to proceed to step S14. On the other hand, in the case where it is determined that the PCV valve 53 is closed (S13: YES), the CPU 71 causes the processing to proceed to step S15.

[0078] In step S14, the CPU 71 determines whether or not the operation state change processing is being executed. That is, the CPU 71 determines whether or not the reason why the PCV valve 53 is not closed is because the operation state change processing is being executed. In the case where the operation state change processing is being executed (S14: YES), the CPU 71 temporarily ends the present processing routine. On the other hand, in the case where the operation state change processing is not being executed (S14: NO), the CPU 71 causes the processing to proceed to step S19.

[0079] In step S15, the CPU 71 determines whether or not at least one of the following two conditions (Al) and (A2) is satisfied.

[0080] Condition (Al): The travel speed SP of the vehicle 10 is equal to or higher than a determination speed SPth.

[0081] Condition (A2): The amount of heat transmitted from the internal combustion engine 20 to the second passage 55 is less than the amount of cooling of the second passage 55 by the running wind.

[0082] Since the running wind is stronger as the running speed SP is higher, the amount of cooling of the blow-by gas supply passage by the running wind is greater. Moreover, as a result of various experiments and simulations, the inventors of the present application have obtained the insight that, in the case where the running speed SP is equal to or higher than the determination speed SPth, the first passage 54 in the blow-by gas supply passage is excessively cooled. Moreover, the inventors of the present application have also obtained the insight that, in the case where the outside air temperature TMP is equal to or lower than the determination temperature TMPth and the PCV valve 53 is closed, if the state where the running speed SP is equal to or higher than the determination speed SPt continues, water is likely to freeze in the first passage 54.

[0083] In addition, the inventors of the present application have obtained the insight that, regardless of whether the running speed SP is equal to or higher than the determination speed SPt, in the case where the above condition (A2) is satisfied, the second passage 55 is excessively cooled. Moreover, the inventors of the present application have also obtained the insight that, in the case where the outside air temperature TMP is equal to or lower than the determination temperature TMPth and the PCV valve 53 is closed, if the condition (A2) is satisfied, water is likely to freeze in the second passage 55.

[0084] Figure 5 Fig. 7 illustrates a map MP1 for determining whether the condition (A2) is satisfied depending on the relationship between the engine speed Ne and the running speed SP. In this map MP1, the line L(l) indicates the relationship between the engine speed Ne and the running speed SP in the case where the transmission 12 selects the first gear stage. The line L(2) indicates the relationship between the engine speed Ne and the running speed SP in the case where the transmission 12 selects the second gear stage. The line L(3) indicates the relationship between the engine speed Ne and the running speed SP in the case where the transmission 12 selects the third gear stage. The line L(N-l) indicates the relationship between the engine speed Ne and the running speed SP in the case where the transmission 12 selects the (N-l)th gear stage. The line L(N) indicates the relationship between the engine speed Ne and the running speed SP in the case where the transmission 12 selects the Nth gear stage. Further, "N" is an integer of 4 or more. The gear ratio of the transmission 12 in the case where the Nth gear stage is selected is the highest speed side gear ratio that can be set by the transmission 12. The gear ratio of the transmission 12 in the case where the (N-l)th gear stage is selected is the second highest speed side gear ratio that can be set by the transmission 12. On the other hand, the gear ratio of the transmission 12 in the case where the first gear stage is selected is the lowest speed side gear ratio that can be set by the transmission 12. Moreover, the determination speed SPth is a value that is determined in advance, and is a value that is determined in advance such that the first passage 54 is not excessively cooled in the case where the running speed SP is equal to or higher than the determination speed SPth. Figure 5The area indicated by the broken line is set as an "excessive cooling area Rp". At this time, the inventors of the present application have obtained the insight that the results of various experiments, simulations are that, in a case where the point indicating the engine speed Ne and the running speed SP is located in the excessive cooling area Rp, the condition (A2) is satisfied.

[0085] Therefore, in the present embodiment, the CPU 71 determines that the first passage 54 is excessively cooled in a case where the condition (Al) is satisfied. In addition, the CPU 71 determines that the second passage 55 is excessively cooled in a case where the condition (A2) is satisfied. Therefore, the processing of step S15 corresponds to "excessive cooling determination processing" that determines whether the blow-by gas supply passage is excessively cooled by the running wind based on the running speed SP.

[0086] Returning to Figure 6 In step S15, in a case where at least one of the conditions (Al) and (A2) is satisfied (S15: YES), the CPU 71 causes the processing to proceed to step S17. On the other hand, in a case where neither of the conditions (Al) and (A2) is satisfied (S15: NO), the CPU 71 causes the processing to proceed to step S19.

[0087] In step S17, the CPU 71 sets both the first execution flag FLGl and the second execution flag FLG2 to be active (ON). In a case where the first execution flag FLGl is set to be active, it is considered that the moisture is likely to freeze in the blow-by gas supply passage. On the other hand, in a case where the first execution flag FLGl is set to be inactive (OFF), it is considered that the moisture does not freeze in the blow-by gas supply passage. In a case where the operation state change processing has not been executed after the first execution flag FLGl is set to be active, the second execution flag FLG2 is set to be active. On the other hand, if the operation state change processing is executed even once after the first execution flag FLGl is set to be active, the second execution flag FLG2 is set to be inactive. Thereafter, the CPU 71 temporarily ends the present processing routine.

[0088] In step S19, the CPU 71 sets the first execution flag FLGl to be inactive. Thereafter, the CPU 71 temporarily ends the present processing routine.

[0089] <Suppression of freezing of moisture in blow-by gas supply passage>

[0090] Referring to Figure 7 The processing routine executed at the time of suppression of freezing of moisture in the blow-by gas supply passage will be described. The processing routine is repeatedly executed by the CPU 71, in each predetermined control cycle.

[0091] In step S31 in the present processing routine, the CPU 71 determines whether activation is set to the first execution flag FLG1. In the case where activation is set to the first execution flag FLG1 (S31: YES), the CPU 71 causes the processing to proceed to step S33. On the other hand, in the case where non-activation is set to the first execution flag FLG1 (S31: NO), the CPU 71 temporarily ends the present processing routine.

[0092] In step S33, the CPU 71 determines whether activation is set to the second execution flag FLG2. In the case where activation is set to the second execution flag FLG2 (S33: YES), the CPU 71 causes the processing to proceed to step S35.

[0093] In step S35, the CPU 71 determines whether at least one of the following two conditions (Bl) and (B2) is satisfied.

[0094] Condition (Bl): A predetermined delay time Tmd has elapsed from the point in time at which activation was set to the first execution flag FLG1.

[0095] Condition (B2): The cumulative time TMt of the state in which activation is set to the first execution flag FLG1 exceeds a determination cumulative time TMtTh.

[0096] For example, a time longer than 1 minute is set as the delay time Tmd. Even if activation is set to the first execution flag FLG1, the moisture will not freeze immediately in the blow-by gas supply passage. In other words, as long as it is a period in which the moisture does not freeze in the blow-by gas supply passage, the operation state change processing can not be executed. Therefore, as a judgment reference of whether the moisture starts to freeze in the blow-by gas supply passage, the delay time Tmd is set.

[0097] In the case where activation is intermittently set to the first execution flag FLG1, even if the duration of the state in which activation is set to the first execution flag FLG1 does not reach the delay time Tmd, the moisture can freeze in the blow-by gas supply passage. Therefore, in the case where the cumulative time TMt exceeds the determination cumulative time TMtTh, it is considered that the moisture can start to freeze in the blow-by gas supply passage. As the determination cumulative time TMtTh, a time longer than the delay time Tmd is set. Further, when the operation state change processing starts, the cumulative time TMt is reset to 0 (zero).

[0098] In step S35, in the case where at least one of the conditions (Bl) and (B2) is satisfied (S35: YES), the CPU 71 causes the processing to proceed to step S39. On the other hand, in the case where neither of the conditions (Bl) and (B2) is satisfied (S35: NO), the CPU 71 causes the processing to proceed to step S37.

[0099] In step S37, the CPU 71 determines whether the operation of the internal combustion engine 20 is shifted from the supercharged operation to the non-supercharged operation, although the operation state change processing is not executed. For example, when the transmission 12 is downshifted by the accelerator operation or the like of the driver, the operation of the internal combustion engine 20 is sometimes shifted from the supercharged operation to the non-supercharged operation, even if the operation state change processing is not executed. When the operation of the internal combustion engine 20 becomes the non-supercharged operation, the pressure of the passage downstream portion 54a of the first passage 54 is sometimes lower than the prescribed pressure, and the PCV valve 53 is opened. Therefore, in a case where the operation of the internal combustion engine 20 is shifted to the non-supercharged operation (S37: YES), the CPU 71 shifts the process to step S39. On the other hand, in a case where the operation of the internal combustion engine 20 is not shifted to the non-supercharged operation (S37: NO), the CPU 71 temporarily ends the present processing routine.

[0100] In step S39, the CPU 71 sets the inactivation to the second execution flag FLG2. Then, the CPU 71 shifts the process to step S41.

[0101] In step S41, the CPU 71 executes the operation state change processing. After that, the CPU 71 temporarily ends the present processing routine.

[0102] On the other hand, in step S33, in a case where the inactivation is set to the second execution flag FLG2 (S33: NO), the CPU 71 shifts the process to step S43.

[0103] In step S43, the CPU 71 determines whether the operation state change processing is being executed. In a case where the operation state change processing is being executed (S43: YES), the CPU 71 shifts the process to step S45. In step S45, the CPU 71 determines whether the duration of the operation state change processing has elapsed the first elapsed time TM1. If the operation state change processing is executed only for the first elapsed time TM1, it can be presumed that, after that, even if the PCV valve 53 is closed, the moisture in the blowthrough passage will not freeze for a certain period of time. Therefore, in a case where the duration of the operation state change processing has not elapsed the first elapsed time TM1 (S45: NO), the CPU 71 shifts the process to step S41. That is, the CPU 71 continues the execution of the operation state change processing.

[0104] On the other hand, in a case where the duration of the operation state change processing has elapsed the first elapsed time TM1 (S45: YES), the CPU 71 causes the processing to proceed to step S47. In step S47, the CPU 71 executes the restoration processing. Specifically, in the restoration processing, the CPU 71 returns the value of the shift stage selected by the transmission 12 to the value of the shift stage before the execution of the operation state change processing. Also, the CPU 71 controls the operation of the internal combustion engine 20 so that the output torque of the internal combustion engine 20 is maintained even if the shift stage selected by the transmission 12 is changed. That is, the restoration processing is processing that allows the operation of the internal combustion engine 20 to return to the supercharged operation and the closed PCV valve 53. After that, the CPU 71 temporarily ends the present processing routine.

[0105] On the other hand, in step S43, in a case where the operation state change processing is not being executed (S43: NO), since the restoration processing is being executed, the CPU 71 causes the processing to proceed to step S49. In the following step S49, the CPU 71 determines whether or not the duration of the restoration processing has elapsed the second elapsed time TM2. If the duration of the restoration processing exceeds the second elapsed time TM2, the possibility that the water is frozen in the blow-by gas supply passage is generated again. Therefore, in a case where the duration of the restoration processing has not elapsed the second elapsed time TM2 (S49: NO), the CPU 71 causes the processing to proceed to step S47. That is, the CPU 71 continues the execution of the restoration processing. On the other hand, in a case where the duration of the restoration processing has elapsed the second elapsed time TM2 (S49: YES), the CPU 71 causes the processing to proceed to step S41. That is, the CPU 71 starts the operation state change processing.

[0106] <Effects of the Present Embodiment>

[0107] The effects in a case where the vehicle 10 is driven in an environment in which the outside air temperature TMP reaches an extremely low temperature below the determination temperature TMPth will be described.

[0108] In a case where the operation of the internal combustion engine 20 is the supercharged operation, the PCV valve 53 is closed. Therefore, in the blow-by gas processing device 50, the blow-by gas of the accumulation chamber 51 is supplied to the intake passage 31 not from the first passage 54 but from the second passage 55.

[0109] Here, the higher the travel speed SP, the greater the amount of cooling of the blow-by gas supply passage by the travel wind. That is, when the travel speed SP is equal to or higher than the determination speed SPth, the amount of cooling of the first passage 54 by the travel wind is greater, and thus the first passage 54 is excessively cooled. In a state in which the blow-by gas does not flow in the first passage 54, in the case where the first passage 54 is excessively cooled, the amount of cooling of the first passage 54 by the travel wind is greater than the amount of heat received by the first passage 54 from the engine 20. Thus, in the state in which the blow-by gas does not flow in the first passage 54, if the first passage 54 is continuously excessively cooled, the moisture present in the first passage 54 can freeze.

[0110] In the case where the blow-by gas flows in the second passage 55, the blow-by gas is cooled by the travel wind. The shortest distance from the connection portion to the intake passage 31 in the second passage 55 to the cylinder 27 is longer than the shortest distance from the connection portion to the intake passage 31 in the first passage 54. Thus, in the case where the second passage 55 is excessively cooled, the amount of heat received by the second passage 55 from the engine 20 due to the blow-by gas flowing in the second passage 55 is not greater than the amount of cooling of the second passage 55 by the travel wind. Thus, if the blow-by gas flows in the second passage 55 in the state where the second passage 55 is excessively cooled, the moisture contained in the blow-by gas can freeze in the second passage 55.

[0111] A case where all of the following conditions are satisfied is referred to as a "moisture freezing condition" being satisfied: the outside air temperature TMP is equal to or lower than the determination temperature TMPth (S11: Yes), it is determined that the PCV valve 53 is closed (S13: Yes), and it is determined that the blow-by gas supply passage is excessively cooled (S15: Yes). In the present embodiment, in the case where the moisture freezing condition is satisfied, the operation state change process (S41) is executed. When the operation state change process is executed, in the transmission 12, a speed stage on the low speed side before the execution of the operation state change process is selected so that both of the following conditions are satisfied: the output torque of the engine 20 is maintained, and the operation of the engine 20 becomes non-supercharged operation. That is, the speed ratio of the transmission 12 is changed to the low speed side.

[0112] By the operation state change process, when the pressure of the passage downstream portion 54a of the first passage 54 is less than the prescribed pressure, the PCV valve 53 is opened. Thereby, the blow-by gas of the accumulation chamber 51 is supplied to the intake passage 31 via the first passage 54. Then, since the blow-by gas of a relatively high temperature flows in the first passage 54, the first passage 54 is heated. That is, the amount of heat received by the first passage 54 from the engine 20 is greater than the amount of cooling of the first passage 54 by the travel wind. Thus, it is possible to suppress the moisture from freezing in the first passage 54.

[0113] On the other hand, when the blow-by gas flows in the first passage 54 by the opening of the PCV valve 53, the blow-by gas does not flow in the second passage 55. Then, the air whose temperature is close to the outside air temperature TMP flows from the intake passage 31 into the second passage 55. The air whose temperature is close to the outside air temperature TMP is not substantially cooled by the running wind during the flow in the second passage 55. As a result, the moisture does not freeze in the second passage 55. That is, in the present embodiment, the freezing of the moisture in the first passage 54 and the second passage 55 can be suppressed during the running of the vehicle 10.

[0114] Further, the present embodiment can also achieve the effects shown below.

[0115] (1-1) In a case where the running speed SP is equal to or higher than the determination speed SPth, it is determined that the first passage 54 is excessively cooled (S15). Also, in a case where it is determined that the first passage 54 is excessively cooled, the PCV valve 53 is opened by executing the operation state changing process. Therefore, the freezing of the moisture in the first passage 54 can be suppressed.

[0116] (1-2) In the present embodiment, it is determined whether the second passage 55 is excessively cooled on the basis of the running speed SP and the engine speed Ne (S15). Also, in a case where it is determined that the second passage 55 is excessively cooled on the basis of the running speed SP and the engine speed Ne, the operation state changing process is executed. Thereby, the freezing of the moisture in the second passage 55 can be suppressed.

[0117] (1-3) When the operation state changing process is executed, the gear selected by the transmission 12 is changed so that the pressure of the passage downstream portion 54a is lower than the prescribed pressure. Therefore, by the execution of the operation state changing process, the PCV valve 53 can be opened. Also, even if the operation state changing process is executed, the output torque of the engine 20 is maintained. Therefore, the change in the running speed SP can be suppressed, and the freezing of the moisture in the first passage 54 and the second passage 55 can be suppressed.

[0118] (1-4) While the operation state changing process is being executed, the transmission 12 does not select the gear on the high speed side. The driver of the vehicle 10 can possibly feel uncomfortable with the fact that the transmission 12 does not select the gear on the high speed side. In addition, even if the above moisture freezing condition is satisfied, the moisture does not freeze in the first passage 54 and the second passage 55 immediately. That is, even if the state in which the PCV valve 53 is closed continues for a certain degree after the execution of the operation state changing process, the moisture does not freeze in the first passage 54 and the second passage 55.

[0119] Therefore, in the present embodiment, the operation state changing process (S41) and the recovery process (S47) are alternately executed. Therefore, even in the case where the water freezing condition is established (S11: S13: S15: YES), it is possible to set a period in which the transmission 12 can select the speed stage on the high speed side. Therefore, it is possible to cause the transmission 12 to select the speed stage on the high speed side, and it is possible to suppress freezing of the water in the first passage 54 and the second passage 55.

[0120] (1-5) In the present embodiment, even if the above water freezing condition is established (S11: S13: S15: YES), during a period (S35: NO) until the delay time TMD elapses, it is possible to continue the state in which the transmission 12 selects the speed stage on the high speed side. On the other hand, when the delay time TMD elapses (S35: YES), the operation state changing process (S41) is executed, and therefore the PCV valve 53 is opened. Thereby, it is possible to set a period in which the transmission 12 selects the speed stage on the high speed side, and it is possible to suppress freezing of the water in the first passage 54 and the second passage 55.

[0121] (1-6) There is a period in which the operation state changing process is not executed even if the above water freezing condition is established (S11: S13: S15: YES). In such a non-execution period of the operation state changing process, sometimes the PCV valve 53 is opened (S37: YES) by a change in the operation state of the internal combustion engine 20. Therefore, in the present embodiment, in the case where the PCV valve 53 is opened by a change in the operation state of the internal combustion engine 20 in the non-execution period of the operation state changing process, it is considered that the PCV valve 53 is opened due to execution of the operation state changing process. Thereby, it is possible to start the recovery process relatively early. That is, it is possible to early release the state in which the transmission 12 is prohibited from selecting the speed stage on the high speed side. Therefore, it is possible to suppress freezing of the water in the first passage 54 and the second passage 55, and it is possible to increase the opportunity in which the transmission 12 can select the speed stage on the high speed side.

[0122] (1-7) Depending on the usage method of the vehicle 10 by the driver, sometimes the operation state changing process is not executed even if the above cumulative time TMt reaches a certain degree. When the cumulative time TMt reaches a certain degree like this, even if the delay time TMD is not reached, the water can start to freeze in at least one of the first passage 54 and the second passage 55. Therefore, in the present embodiment, in the case where the cumulative time TMt exceeds the determination cumulative time TMtTh (S35: YES), the operation state changing process (S41) is started even if the duration of the state in which the above water freezing condition is established does not reach the delay time TMD. Thereby, it is possible to suppress freezing of the water in at least one of the first passage 54 and the second passage 55 due to non-execution of the operation state changing process.

[0123] According to Figure 8A second embodiment of the vehicle control device will be described. Also, in the second embodiment, a part of the processing content of the vehicle control device and the like is different from the first embodiment. In the following description, mainly the part different from the first embodiment will be described, the same reference numerals are given to the same component configurations as those of the first embodiment, and overlapping description will be omitted.

[0124] <Processing of determining whether there is a possibility that moisture freezes in the blow-by gas supply passage>

[0125] Referring to Figure 8 A processing routine of determining whether there is a possibility that moisture freezes in the blow-by gas supply passage will be described. The processing routine is repeatedly executed by the CPU 71 by a control program, and is repeatedly executed in each predetermined control cycle.

[0126] In the present processing routine, in step Sll, the CPU 71 determines whether the outside air temperature TMP of the vehicle 10 is below the determination temperature TMPth. In a case where the outside air temperature TMP is higher than the determination temperature TMPth (Sll: No), the CPU 71 causes the processing to proceed to step S19. On the other hand, in a case where the outside air temperature TMP is below the determination temperature TMPth (Sll: Yes), the CPU 71 causes the processing to proceed to step S13.

[0127] In step S13, the CPU 71 determines whether the PCV valve 53 is closed. In a case where it is determined that the PCV valve 53 is not closed (S13: No), the CPU 71 causes the processing to proceed to step S14. On the other hand, in a case where it is determined that the PCV valve 53 is closed (S13: Yes), the CPU 71 causes the processing to proceed to step S15.

[0128] In step S14, the CPU 71 determines whether the operation state change processing is being executed. In a case where the operation state change processing is being executed (S14: Yes), the CPU 71 temporarily ends the present processing routine. On the other hand, in a case where the operation state change processing is not being executed (S14: No), the CPU 71 causes the processing to proceed to step S19.

[0129] In step S15, the CPU 71 determines whether at least one of the above-described two conditions (Al) and (A2) is satisfied. In a case where at least one of the conditions (Al) and (A2) is satisfied (S15: Yes), the CPU 71 causes the processing to proceed to step S17. On the other hand, in a case where neither of the conditions (Al) and (A2) is satisfied (S15: No), the CPU 71 causes the processing to proceed to step S19.

[0130] In step S17, the CPU 71 sets both the first execution flag FLGl and the second execution flag FLG2 to active. Thereafter, the CPU 71 temporarily ends the present processing routine.

[0131] In step S19, the CPU 71 sets the first execution flag FLG1 to inactive. In the next step S21, the CPU 71 executes a reduction process of reducing the above-mentioned accumulated time TMt. For example, the CPU 71 derives the larger one of the value obtained by subtracting a predetermined correction time ΔTM from the accumulated time TMt and 0 (zero) as a new accumulated time TMt. After that, the CPU 71 temporarily ends the present processing routine.

[0132] Effects of the Present Embodiment

[0133] In the present embodiment, in addition to the effects (1-1) to (1-7) equivalent to those in the above-mentioned first embodiment, the following effects are also obtained.

[0134] (2-1) In the case where the above-mentioned moisture freezing condition does not hold, the moisture does not freeze in the first passage 54 and the second passage 55. Therefore, in the present embodiment, in the case where the moisture freezing condition does not hold (S11: No, S13: No, S15: No), the accumulated time TMt is reduced (S21). Thereby, it is possible to suppress the case where the operation state change process is started although the moisture does not freeze in the first passage 54 and the second passage 55 but the accumulated time TMt reaches the determination accumulated time TMtTh or more. Therefore, it is possible to suppress the moisture from freezing in the first passage 54 and the second passage 55, and it is possible to suppress the execution frequency of the operation state change process from increasing.

[0135] According to Figure 9 and Figure 10 A third embodiment of the vehicle control device will be described. Furthermore, in the third embodiment, the vehicle to which the vehicle control device is applied is a hybrid vehicle, and the content of the operation state change process and the like are different from those of the above-mentioned multiple embodiments. In the following description, mainly the portions different from the above-mentioned multiple embodiments will be described, the same reference numerals are given to the same component configurations as those of the above-mentioned multiple embodiments, and the repeated description will be omitted.

[0136] Figure 9 A vehicle 10A to which a control device 70 serving as a vehicle control device is applied is illustrated. The vehicle 10A is a hybrid vehicle provided with an internal combustion engine 20 and a motor generator 100 as a power source.

[0137] Process for suppressing freezing of moisture in blow-by gas supply passage

[0138] With reference to Figure 10 A processing routine for suppressing freezing of moisture in a blow-by gas supply passage will be described. The processing routine is repeatedly executed by the CPU 71, and is repeatedly executed in each predetermined control cycle.

[0139] In step S61 in the present processing routine, the CPU 71 determines whether or not the outside air temperature TMP is lower than the determination temperature TMPth, similarly to step Sll described above. In the case where the outside air temperature TMP is lower than the determination temperature TMPth (S61: YES), the CPU 71 causes the processing to proceed to step S63. On the other hand, in the case where the outside air temperature TMP is higher than the determination temperature TMPth (S61: NO), the CPU 71 causes the processing to proceed to step S71.

[0140] In step S63, the CPU 71 determines whether or not at least one of the above two conditions (Al) and (A2) is satisfied, similarly to step S15 described above. In the case where at least one of the two conditions (Al) and (A2) is satisfied (S63: YES), the CPU 71 causes the processing to proceed to step S65. On the other hand, in the case where neither of the two conditions (Al) and (A2) is satisfied (S63: NO), the CPU 71 causes the processing to proceed to step S71.

[0141] In step S65, the CPU 71 determines whether or not the PCV valve 53 is closed, similarly to step S13 described above. In the case where it is determined that the PCV valve 53 is closed (S65: YES), the CPU 71 causes the processing to proceed to step S69. On the other hand, in the case where it is determined that the PCV valve 53 is not closed (S65: NO), the CPU 71 causes the processing to proceed to step S67.

[0142] In step S67, the CPU 71 determines whether or not the operation state change processing is being executed. In the case where the operation state change processing is being executed (S67: YES), the CPU 71 temporarily ends the present processing routine. That is, the CPU 71 continues the execution of the operation state change processing. On the other hand, in the case where the operation state change processing is not being executed (S67: NO), the CPU 71 causes the processing to proceed to step S71.

[0143] In step S69, the CPU 71 executes the operation state change processing. That is, the CPU 71 sets the operation of the internal combustion engine 20 to the non-supercharged operation in the operation state change processing, so as to make the pressure of the passage downstream portion 54a of the first passage 54 smaller than the prescribed pressure. When the operation state of the internal combustion engine 20 is thus changed, the drive torque input to the drive wheels 14 is reduced. Therefore, in the present embodiment, the CPU 71 increases the output torque of the motor generator 100 in the operation state change processing, so as to compensate for the reduction in the output torque of the internal combustion engine 20. After that, the CPU 71 temporarily ends the present processing routine.

[0144] In step S71, the CPU 71 stops the operation state change processing. That is, the CPU 71 reduces the output torque of the motor generator 100 as compared to before the operation state change processing, and on the other hand, increases the output torque of the internal combustion engine 20. That is, the CPU 71 allows the operation of the internal combustion engine 20 to become supercharged operation. After that, the CPU 71 temporarily ends the present processing routine.

[0145] <Effects of the Present Embodiment>

[0146] The present embodiment will be described focusing on the effects thereof that are different from the effects of the above-described embodiments.

[0147] When the above-described moisture freezing condition is satisfied (S61: S63: S65: YES), the moisture is likely to freeze in the first passage 54 and the second passage 55, and thus the operation state change processing is executed (S69). Specifically, the operation of the internal combustion engine 20 becomes non-supercharged operation so as to make the pressure of the passage downstream portion 54a of the first passage 54 less than the prescribed pressure. In addition, the output torque of the motor generator 100 is increased so as to compensate for the reduction in the output torque of the internal combustion engine 20 due to the reduction in the pressure of the passage downstream portion 54a. Thereby, it is possible to suppress the change in the vehicle speed SP of the vehicle 10A with the execution of the operation state change processing.

[0148] When the pressure of the passage downstream portion 54a is less than the prescribed pressure, the PCV valve 53 is opened (S65: NO). Therefore, the blow-by gas of the accumulation chamber 51 is supplied to the intake passage 31 via the first passage 54. By thus making the blow-by gas of a relatively high temperature flow in the first passage 54, it is possible to suppress the freezing of the moisture in the first passage 54. When the blow-by gas flows in the first passage 54 by the opening of the PCV valve 53, the blow-by gas does not flow to the second passage 55. As a result, it is possible to suppress the freezing of the moisture in the second passage 55. Therefore, in the present embodiment, it is possible to suppress the reduction in the vehicle speed SP of the vehicle 10A, and it is possible to suppress the freezing of the moisture in the first passage 54 and the second passage 55.

[0149] Further, in the present embodiment, effects equivalent to the effects (1-1) and (1-2) of the above-described first embodiment can also be obtained.

[0150] <Alterations>

[0151] The above-described embodiments can be implemented as follows. The above-described embodiments and the following alterations can be implemented in combination with each other within a range in which they do not contradict in technology.

[0152] • In the operation state change processing performed in the above-described third embodiment, since the output torque of the motor generator 100 is increased, in a case where the charge level of the battery is not too much, it can not be possible to perform the operation state change processing. Therefore, when the vehicle 10A is provided with a transmission, in a case where the charge level of the battery is the determination charge level or more, it is preferable to perform the operation state change processing explained in the third embodiment. On the other hand, in a case where the charge level of the battery is less than the determination charge level, it is possible to perform the operation state change processing explained in the first embodiment and the second embodiment.

[0153] • In the above-described first embodiment and the second embodiment, the transmission provided to the vehicle 10 can also be a continuously variable transmission.

[0154] • In the above-described second embodiment, in a case where the conditions in at least one of the determinations in steps Sll, S13, and S15 shown in FIG. 6 are not satisfied, the accumulated time TMt is reduced (S21), but is not limited thereto. For example, in such a case, it is also possible to reset the accumulated time TMt to 0 (zero). Figure 8

[0155] • In the above-described first embodiment, it is also possible not to count the accumulated time TMt.

[0156] • In the above-described first embodiment and the second embodiment, it is also possible not to alternately perform the operation state change processing and the restoration processing. That is, it is also possible to continue the operation state change processing when the duration of the state in which the moisture freezing condition is satisfied reaches the delay time TMD.

[0157] • In the above-described first embodiment and the second embodiment, in a case where it is determined that the outside air temperature TMP is the determination temperature TMPth or less (SI l: YES), the PCV valve 53 is closed (S13: YES), and further, it is determined that the blow-by gas supply passage is excessively cooled (S15: YES), it is also possible to start the operation state change processing without waiting for the passage of the delay time TMD.

[0158] • In the above-described embodiments, the excessive cooling determination processing (S13) can also be processing that includes at least one of processing that determines whether the running speed SP is the determination speed SPth or more, and processing that determines whether the second passage 55 is excessively cooled based on the running speed SP and the engine speed Ne.

[0159] • The lower the outside air temperature TMP, the more easily moisture freezes in the blow-by gas supply passage. Therefore, it is also possible that the lower the outside air temperature TMP, the shorter time is set as the delay time TMD. In addition, it is also possible that the lower the outside air temperature TMP, the shorter time is set as the determination accumulated time TMtTh.​

[0160] • It can also be that the lower the outside air temperature TMP, the lower speed is set as the determination speed SPth.

[0161] In addition, it can also be that the lower the outside air temperature TMP, the longer time is set as the first elapsed time TM1. It can also be that the lower the outside air temperature TMP, the shorter time is set as the second elapsed time TM2.

[0162] • In the above-described embodiments, it is determined that the PCV valve 53 is closed when the estimated value of the pressure of the portion of the intake passage 31 downstream of the throttle valve 32 is a predetermined pressure or more, but not limited thereto. For example, in the case where the internal combustion engine 20 is provided with a sensor that detects the pressure of the portion of the intake passage 31 downstream of the throttle valve 32, it can also be determined that the PCV valve 53 is closed when the detected value of the sensor is a predetermined pressure or more.

[0163] • The control device 70 is not limited to having a CPU and a ROM to execute software processing. That is, the control device 70 can be any one of the following (a) to (c) structures.

[0164] (a) The control device 70 has one or more processors that execute various processes according to computer programs. The processor includes a CPU and a memory such as a RAM and a ROM. The memory stores program codes or instructions that cause the CPU to execute processes. The memory, i.e., the non-transitory computer readable storage medium, includes all available media that can be accessed by a general or special purpose computer.

[0165] (b) The control device 70 has one or more dedicated hardware circuits that execute various processes. As the dedicated hardware circuit, for example, an integrated circuit for a specific purpose, i.e., an ASIC or an FPGA, can be cited. In addition, ASIC is an abbreviation for "Application Specific Integrated Circuit", and FPGA is an abbreviation for "Field Programmable Gate Array".

[0166] (c) The control device 70 has a processor that executes a part of various processes according to computer programs, and a dedicated hardware circuit that executes the remaining processes of the various processes.

[0167] Further, the expression "at least 1" as used in the present specification means "1 or more" of the desired option. As an example, the expression "at least 1" as used in the present specification means "only 1 option" or "both of the two options" if the number of options is two. As another example, the expression "at least 1" as used in the present specification means "only 1 option" or "a combination of any two or more options" if the number of options is three or more.

Claims

1. A vehicle control device, applied to a vehicle equipped with an internal combustion engine, wherein, The vehicle control device includes an execution circuit. The execution circuit is configured to execute: The process involves determining whether the PCV valve of the blow-by treatment device is closed. The turbocharger of the internal combustion engine has a turbine located in the exhaust passage and a compressor located in the intake passage of the internal combustion engine. The blow-by treatment device has a supply passage for supplying blow-by gas to the intake passage. The supply passage has a first passage and a second passage. The first passage is connected to a portion of the intake passage downstream of the compressor, and the second passage is connected to a portion of the intake passage upstream of the compressor. The PCV valve is disposed in the first passage. The first passage has a connection portion to the intake passage. The downstream portion of the passage is the portion between the connection portion and the PCV valve in the first passage. The PCV valve closes when the pressure in the downstream portion of the passage reaches a predetermined pressure or higher. Overcooling determination process: Based on the vehicle's driving speed, determine whether the supply passage is overcooled by the vehicle's driving airflow. and In the operation status change processing, if the external temperature of the vehicle is below the specified temperature, the PCV valve is determined to be closed in the valve closure determination process, and the supply passage is determined to be overcooled in the overcooling determination process, the operation of the internal combustion engine is set to non-turbocharged operation, thereby making the pressure in the downstream part of the passage less than the specified pressure. Boosted operation is the operation of the internal combustion engine by pressurizing the intake air flowing in the intake passage through the turbocharger, while non-turbocharged operation is the operation of the internal combustion engine without pressurizing the intake air through the turbocharger.

2. The vehicle control device according to claim 1, wherein, The execution circuit is configured such that, in the overcooling determination process, if the travel speed is above the determination speed, it is determined that the supply passage is overcooled.

3. The vehicle control device according to claim 1, wherein, The execution circuit is configured to determine whether the supply passage is overcooled based on the driving speed and the internal combustion engine speed during the overcooling determination process.

4. The vehicle control device according to any one of claims 1 to 3, wherein, The vehicle is equipped with a transmission device. The operation status change processing includes the processing of changing the gear ratio of the transmission device.

5. The vehicle control device according to claim 4, wherein, The execution circuit is configured to alternately and repeatedly perform the operation state change processing and recovery processing when the external temperature is below the determined temperature, the PCV valve is determined to be closed by the valve closure determination process, and the supply passage is determined to be overcooled by the overcooling determination process. The recovery process restores the gear ratio value to the value before the operation state change process began.

6. The vehicle control device according to claim 4, wherein, The execution circuit is configured such that, when the external temperature is below the determined temperature, the PCV valve is determined to be closed by the valve closure determination process, and the supply passage is determined to be overcooled by the overcooling determination process, the operation state change process is initiated after a predetermined delay time.

7. The vehicle control device according to claim 5, wherein, The execution circuit is configured such that, when the external temperature is below the determined temperature, the PCV valve is determined to be closed by the valve closure determination process, and the supply passage is determined to be overcooled by the overcooling determination process, the PCV valve is determined to be opened by the execution of the operation state change process during the period when the operation state change process is not executed.

8. The vehicle control device according to claim 6, wherein, The execution circuit is configured to execute: The cumulative time for the conditions where the external temperature is below the determination temperature, the PCV valve is determined to be closed by the valve closure determination process, and the supply passage is determined to be over-cooled by the over-cooling determination process are all established are measured. If the aforementioned operational status change process has been initiated, the accumulated time will be reset; and When the accumulated time exceeds the determination accumulated time, the operation status change process is started, and the determination accumulated time is set to be longer than the delay time.

9. The vehicle control device according to claim 8, wherein, The execution circuit is configured to reset the accumulated time or reduce the accumulated time if at least one of the following conditions is not met: the external temperature is below the determined temperature; the PCV valve is determined to be closed by the valve closure determination process; or the supply passage is determined to be overcooled by the overcooling determination process.

10. The vehicle control device according to any one of claims 1 to 3, wherein, The vehicle in question is a hybrid vehicle that also has an electric generator as a power source. The operation status change processing includes increasing the output torque of the electric generator.

11. A vehicle control method, applicable to vehicles equipped with internal combustion engines, wherein, The vehicle control method includes: The blow-by device determines whether the PCV valve of the blow-by treatment device is closed by means of an execution circuit. The turbocharger of the internal combustion engine has a turbine disposed in the exhaust passage and a compressor disposed in the intake passage of the internal combustion engine. The blow-by treatment device has a supply passage for supplying blow-by gas to the intake passage. The supply passage has a first passage and a second passage. The first passage is connected to a portion of the intake passage downstream of the compressor. The second passage is connected to a portion of the intake passage upstream of the compressor. The PCV valve is disposed in the first passage. The first passage has a connection portion to the intake passage. The downstream portion of the passage is the portion between the connection portion of the first passage and the PCV valve. The PCV valve closes when the pressure in the downstream portion of the passage reaches a predetermined pressure or higher. The execution circuit determines, based on the vehicle's speed, whether the supply passage is excessively cooled by the vehicle's airflow; and When the external temperature of the vehicle is below the predetermined temperature, the PCV valve is determined to be closed, and the supply passage is determined to be overcooled, the operation of the internal combustion engine is set to non-turbocharged operation by the execution circuit, so that the pressure in the downstream part of the passage is less than the predetermined pressure. Boost operation is the operation of the internal combustion engine by pressurizing the intake air flowing in the intake passage through the turbocharger, while non-turbocharged operation is the operation of the internal combustion engine without pressurizing the intake air through the turbocharger.

12. A storage medium, a non-transitory computer-readable storage medium, storing a program that causes a processing device to perform vehicle control processing applied to a vehicle equipped with an internal combustion engine, wherein... The vehicle control process includes: The blow-by device determines whether the PCV valve of the blow-by treatment device is closed by means of an execution circuit. The turbocharger of the internal combustion engine has a turbine disposed in the exhaust passage and a compressor disposed in the intake passage of the internal combustion engine. The blow-by treatment device has a supply passage for supplying blow-by gas to the intake passage. The supply passage has a first passage and a second passage. The first passage is connected to a portion of the intake passage downstream of the compressor. The second passage is connected to a portion of the intake passage upstream of the compressor. The PCV valve is disposed in the first passage. The first passage has a connection portion to the intake passage. The downstream portion of the passage is the portion between the connection portion of the first passage and the PCV valve. The PCV valve closes when the pressure in the downstream portion of the passage reaches a predetermined pressure or higher. The execution circuit determines, based on the vehicle's speed, whether the supply passage is excessively cooled by the vehicle's airflow; and When the external temperature of the vehicle is below the predetermined temperature, the PCV valve is determined to be closed, and the supply passage is determined to be overcooled, the operation of the internal combustion engine is set to non-turbocharged operation by the execution circuit, so that the pressure in the downstream part of the passage is less than the predetermined pressure. Boost operation is the operation of the internal combustion engine by pressurizing the intake air flowing in the intake passage through the turbocharger, while non-turbocharged operation is the operation of the internal combustion engine without pressurizing the intake air through the turbocharger.

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