Vehicle control device

Abstract

To provide a vehicle control device capable of suppressing overheat of a portion exposed to the outside of an exhaust pipe in an exhaust temperature sensor.SOLUTION: A vehicle control device 130 controls an electric fan 43 for taking the outside air into an engine compartment. The vehicle control device 130 acquires an exhaust temperature detected by an exhaust temperature sensor 200 mounted on an exhaust pipe 17 of an engine, and a vehicle speed detected by a vehicle speed sensor 140. The vehicle control device 130 includes a processing circuit 131. The processing circuit 131 executes temperature estimation processing for calculating an estimated temperature of a screw part 230 of the exhaust temperature sensor 200 on the basis of the exhaust temperature and the vehicle speed. Also, the processing circuit 131 executes air blowing processing for operating the electric fan 43 in the case where the estimated temperature is equal to or greater than a threshold value when the vehicle speed falls below a determination vehicle speed.SELECTED DRAWING: Figure 2

Description

[Technical Field]

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

[0002] Patent Document 1 discloses a vehicle control device. An exhaust temperature sensor that detects the temperature of exhaust gas flowing through an exhaust passage is attached to an exhaust pipe. The vehicle control device disclosed in Patent Document 1 is connected to the exhaust temperature sensor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2020 / 095416 Summary of the Invention [Problem to be solved by the invention]

[0004] When the vehicle is moving, the wind flows into the engine compartment through the front grille. Therefore, the part of the exhaust temperature sensor exposed to the outside of the exhaust pipe is cooled by the wind flowing through the engine compartment. However, when the vehicle is stopped, if the cooling by the wind is not sufficient, the temperature of this part may become excessively high due to heat transfer from the exhaust pipe. [Means for solving the problem]

[0005] The means for solving the above problems and their effects will be described below. A vehicle control device for solving the above problem controls an electric fan that draws outside air into an engine compartment. The vehicle control device includes a processing circuit that executes a temperature estimation process that acquires exhaust temperature detected by an exhaust temperature sensor attached to an engine exhaust pipe and vehicle speed detected by a vehicle speed sensor, and calculates an estimated temperature of a specific portion of the exhaust temperature sensor based on the exhaust temperature and the vehicle speed, and a blowing process that operates the electric fan if the estimated temperature is equal to or higher than a threshold when the vehicle speed falls below a threshold vehicle speed. [Effects of the Invention]

[0006] The above vehicle control device can prevent the electric fan from being driven unnecessarily, and can also prevent the portion of the exhaust temperature sensor that is exposed to the outside of the exhaust pipe from overheating. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic diagram showing an engine and a vehicle control device mounted on a vehicle. [Figure 2] FIG. 2 is a schematic diagram showing the general configuration of the exhaust temperature sensor and the vehicle control device. [Figure 3] FIG. 3 is a time chart showing the temperature transitions of the threaded portion and the bushing portion. [Figure 4] FIG. 4 is a flowchart showing the flow of the temperature estimation process. [Figure 5] FIG. 5 is a flowchart showing the flow of the process for starting the air blowing process. [Figure 6] FIG. 6 is a flowchart showing the flow of the process for ending the air blowing process. DETAILED DESCRIPTION OF THE INVENTION

[0008] An embodiment of a vehicle control device will be described below with reference to FIGS. <Configuration of vehicle 100> As shown in FIG. 1, an engine 10 is mounted in an engine compartment 110 of a vehicle 100. An exhaust pipe 17 is attached to the engine 10. An exhaust manifold 11 is provided in a cylinder head of the engine 10. The exhaust pipe 17 is connected to the exhaust manifold 11. An exhaust purification device 18 is attached midway through the exhaust pipe 17. The exhaust pipe 17 passes under the floor of the vehicle 100 and extends toward the rear of the vehicle 100. An exhaust temperature sensor 200 is attached to the exhaust pipe 17 in a portion upstream of the exhaust purification device 18.

[0009] As shown in FIG. 1 , vehicle 100 is provided with a front grille 120 at its front end, which draws outside air into engine compartment 110. When vehicle 100 is moving forward, some of the airflow is drawn into engine compartment 110 through front grille 120. Vehicle 100 is also provided with a radiator 42 in engine compartment 110. Radiator 42 is connected to engine 10 via a coolant passage 45. A water pump 44 is provided in coolant passage 45. Radiator 42 is disposed between front grille 120 and engine 10. Radiator 42 dissipates heat from the coolant of engine 10 by exchanging heat with outside air. Radiator 42 is combined with an electric fan 43 to form a unit. Electric fan 43 draws outside air into engine compartment 110 through front grille 120. Electric fan 43 draws outside air into radiator 42, promoting heat dissipation from the coolant.

[0010] The engine 10 is electrically connected to the vehicle control device 130 via a wire harness. The vehicle control device 130 controls the engine 10. The vehicle control device 130 controls not only the engine 10 but also each part of the vehicle 100. For example, the vehicle control device 130 adjusts the power supplied to the electric fan 43 to control the rotation speed of the electric fan 43.

[0011] <Configuration of vehicle control device 130> 2, the vehicle control device 130 includes a storage device 132 that stores a program, and a processing circuit 131. The processing circuit 131 executes the program stored in the storage device 132 to perform various types of control.

[0012] Various sensors that detect the state of the engine 10 and the state of the vehicle 100 are connected to the vehicle control device 130. For example, a vehicle speed sensor 140 that detects a vehicle speed SPD, which is the speed of the vehicle 100, is connected to the vehicle control device 130. A voltage sensor 141 is connected to the vehicle control device 130. The voltage sensor 141 detects the voltage Vb of a battery that supplies power to electrical components including the electric fan 43. An air flow meter 142 is connected to the vehicle control device 130. The air flow meter 142 detects an intake air temperature THA and an intake air amount Ga. The intake air temperature THA is the temperature of air taken into the cylinders through the intake passage of the engine 10. The intake air amount Ga is the mass of air taken into the cylinders through the intake passage of the engine 10. A crank position sensor 143 is connected to the vehicle control device 130. The crank position sensor 143 outputs a crank angle signal that corresponds to a change in the rotational phase of a crankshaft, which is the output shaft of the engine 10. The vehicle control device 130 calculates an engine speed NE based on the crank angle signal. The engine speed NE is the rotation speed of the crankshaft. A water temperature sensor 144 is connected to the vehicle control device 130. The vehicle control device 130 calculates an engine load factor KL based on the engine speed NE and the intake air amount Ga. The engine load factor KL is an index value of the air filling rate in the combustion chamber of the engine 10. Specifically, the engine load factor KL is the ratio of the amount of inflow air per combustion cycle of one cylinder to a reference inflow air amount. The reference inflow air amount is variably set according to the engine speed NE. A water temperature sensor 144 is connected to the vehicle control device 130. The water temperature sensor 144 detects a water temperature THW, which is the temperature of the coolant flowing through the coolant passage 45. The vehicle control device 130 controls the operation of the electric fan 43 according to the water temperature THW. For example, the vehicle control device 130 does not operate the electric fan 43 when the water temperature THW is lower than a predetermined temperature. When the water temperature THW is equal to or higher than a predetermined temperature, the vehicle control device 130 increases the rotation speed of the electric fan 43 as the water temperature THW increases. An accelerator position sensor 145 is connected to the vehicle control device 130. The accelerator position sensor 145 detects the amount of accelerator operation. A brake sensor 146 is connected to the vehicle control device 130.The brake sensor 146 detects the amount of braking operation. The exhaust gas temperature sensor 200 is connected to the vehicle control device 130. The exhaust gas temperature sensor 200 is installed in a portion of the exhaust pipe 17 upstream of the exhaust gas purification device 18. The exhaust gas temperature sensor 200 detects the exhaust gas temperature Thex.

[0013] <Configuration of exhaust temperature sensor 200> As shown in FIG. 2, the exhaust temperature sensor 200 includes a sensor body 210, a case 220, a threaded portion 230, a wire 240, and a bushing 250. The sensor body 210 includes a temperature-sensing portion at its tip that detects the temperature of the exhaust gas. The end of the sensor body 210 is housed in a cylindrical case 220. A wire 240 is connected to the end of the sensor body 210. The wire 240 is connected to the vehicle control device 130. The case 220 is made of, for example, stainless steel. The end of the case 220 is attached to the threaded portion 230. The threaded portion 230 is made of, for example, stainless steel. The threaded portion 230 includes a hole through which the sensor body 210 is inserted. The sensor body 210 is inserted into this hole. The outer peripheral surface of the threaded portion 230 is a male thread. The end of the case 220 is covered by a bushing 250. The bushing 250 is made of, for example, rubber. The bushing 250 prevents the wire 240 from being damaged due to contact between the end of the case 220 and the wire 240 .

[0014] As shown in FIG. 2 , the exhaust pipe 17 has a mounting boss 171. The inner circumferential surface of the mounting boss 171 is female-threaded. The exhaust temperature sensor 200 is attached to the exhaust pipe 17 by threading the male threads of the threaded portion 230 into the female threads of the mounting boss 171. As a result, the temperature-sensing portion of the exhaust temperature sensor 200 is located inside the exhaust pipe 17. On the other hand, a portion of the threaded portion 230, the case 220, the bushing 250, and the wire 240 are exposed to the outside of the exhaust pipe 17. In addition, the threaded portion 230 is in contact with the exhaust pipe 17.

[0015] <About Busch 250 overheating while idling> When vehicle 100 is moving, wind flows into engine compartment 110 from front grille 120. Therefore, the portion of exhaust temperature sensor 200 that is exposed to the outside of exhaust pipe 17 is cooled by the wind flowing through engine compartment 110. However, if cooling by the wind is not sufficient, such as when vehicle 100 is stopped, the temperature of the portion of exhaust temperature sensor 200 that is exposed to the outside of exhaust pipe 17 may become excessively high due to heat transfer from exhaust pipe 17.

[0016] Solid line L1 in FIG. 3 shows the temperature change over time of thread portion 230 of exhaust temperature sensor 200. Solid line L2 in FIG. 3 shows the temperature change over time of bushing 250 of exhaust temperature sensor 200. The data shown in FIG. 3 is experimental data obtained by running vehicle 100 with a temperature sensor attached to thread portion 230 and bushing 250. In the experiment shown in FIG. 3, vehicle 100 starts running at time T0. In this experiment, vehicle 100 stops at time T10. Vehicle 100 continues to stop after time T10. Note that in this experiment, after time T10, engine 10 continues to operate in an idling state even while the vehicle is stopped. In this experiment, electric fan 43 is stopped during idling operation after time T10.

[0017] As described above, the threaded portion 230 is in contact with the exhaust pipe 17. The threaded portion 230 is heated together with the exhaust pipe 17 by the heat of the exhaust while the vehicle is running. Therefore, as shown by the solid line L1, the temperature of the threaded portion 230 continues to rise while the vehicle is running. If the vehicle 100 accelerates and the vehicle speed SPD remains high, the rate at which the temperature of the threaded portion 230 rises increases. The temperature of the threaded portion 230 at time T10 reaches "Th10". After time T10, the vehicle is idling, so the amount of heat received from the exhaust is small. Therefore, after time T10, the temperature of the threaded portion 230 gradually decreases due to heat dissipation.

[0018] The bushing 250 is exposed to the outside of the exhaust pipe 17. Therefore, the threaded portion 230 is cooled by the wind flowing through the engine compartment 110 while the vehicle is traveling. Therefore, although heat is transferred from the threaded portion 230 via the case 220, the temperature of the bushing 250 is less likely to rise than the temperature of the threaded portion 230 while the vehicle is traveling. Furthermore, when the vehicle 100 accelerates and the vehicle speed SPD increases, cooling by the wind is promoted, and the temperature of the bushing 250 decreases. After time T10, the vehicle 100 stops and cooling by the wind is no longer performed, so the temperature of the bushing 250 increases due to heat transfer from the threaded portion 230 via the case 220. "Thx" is the heat-resistant limit temperature of the bushing 250. In the example shown in FIG. 3, the temperature of the bushing 250 exceeds "Thx" after time T10. To prevent such overheating, the vehicle control device 130 executes an estimation process to estimate the temperature of the threaded portion 230. The vehicle control device 130 then executes the air blowing process when the estimated temperature Thest of the threaded portion 230 when the vehicle 100 is stopped is equal to or higher than the threshold value Thth. The air blowing process is a process that operates the electric fan 43 even if the water temperature THW is lower than the predetermined temperature.

[0019] <About temperature estimation processing> FIG. 4 is a flowchart showing the flow of processing in a routine related to temperature estimation processing. The routine shown in FIG. 4 is repeatedly executed by the processing circuit 131 while the vehicle control device 130 is operating. As shown in FIG. 4, when the processing circuit 131 starts this routine, it first calculates a temperature base value Thbs in the processing of step S100. Specifically, the processing circuit 131 calculates the product of the exhaust temperature detected by the exhaust temperature sensor 200 multiplied by a correction coefficient. This product is then set as the temperature base value Thbs. The correction coefficient is a positive value smaller than "1.0" that is set through experiments conducted in advance so that the estimated temperature Thest can be calculated based on the exhaust temperature through the temperature estimation processing.

[0020] Next, in the process of step S110, the processing circuit 131 calculates the correction value Thcorr. Specifically, the processing circuit 131 calculates the correction value Thcorr by performing an operation using the vehicle speed SPD and the intake air temperature THA as inputs. The processing circuit 131 calculates the correction value Thcorr so that the higher the vehicle speed SPD is, the larger the value becomes. Furthermore, the processing circuit 131 calculates the correction value Thcorr so that the lower the intake air temperature THA is, the larger the value becomes. Note that when the air flow meter 142 is malfunctioning, the processing circuit 131 calculates the correction value Thcorr by regarding the intake air temperature THA as 40°C.

[0021] Next, in the process of step S120, the processing circuit 131 calculates the corrected base value Thbsc. Specifically, the processing circuit 131 subtracts the correction value Thcorr from the temperature base value Thbs. Then, the processing circuit 131 sets the obtained difference as the corrected base value Thbsc.

[0022] Next, in the process of step S130, the processing circuit 131 calculates the time constant τ. Specifically, the processing circuit 131 calculates a smaller time constant τ, assuming that the greater the intake air amount Ga, the greater the exhaust flow rate. Then, in the process of the next step S140, the processing circuit 131 calculates the estimated temperature Thest, which is an estimate of the temperature of the thread portion 230. The vehicle control device 130 calculates the correction value Thcorr as a value that changes to the corrected base value Thbsc with a first-order lag element. Specifically, the processing circuit 131 calculates a quotient by dividing the difference obtained by subtracting the estimated temperature Thest calculated through the previous process of step S140 from the corrected base value Thbsc by the time constant τ. The processing circuit 131 then adds this quotient to the estimated temperature Thest calculated through the previous process of step S140, and sets the calculated sum as a new estimated temperature Thest. That is, the process of step S140 is a process of calculating the estimated temperature Thest by performing first-order delay processing on the corrected base value Thbsc using a time constant τ that decreases as the exhaust flow rate increases. The series of processes from step S100 to step S140 is the temperature estimation process. After executing the temperature estimation process and calculating a new estimated temperature Thest, the processing circuit 131 temporarily ends this routine.

[0023] <About ventilation treatment> Next, the routine for the air blowing process will be described with reference to Figures 5 and 6. Figure 5 shows the flow of processing in the routine for starting the air blowing process. The routine shown in Figure 5 is executed by the processing circuit 131 every time the estimated temperature Thest is updated through the temperature estimation process shown in Figure 4. Note that this routine is not executed while the air blowing process is being executed after the air blowing process has started.

[0024] When this routine starts, the processing circuit 131 first determines in step S200 whether the estimated temperature Thest is equal to or greater than a threshold value Thth. The threshold value Thth is set to a value such that, based on the estimated temperature Thest being equal to or greater than the threshold value Thth, it can be determined that the bushing 250 may overheat if cooling by wind from traveling is not performed. If the processing circuit 131 determines in step S200 that the estimated temperature Thest is less than the threshold value Thth (step S200: NO), the processing circuit 131 proceeds to step S240. Then, in step S240, the processing circuit 131 sets the overheat condition flag to "0." Note that the overheat condition flag, when set to "1," indicates that the bushing 250 may overheat. After executing the processing of step S240, the processing circuit 131 temporarily ends this routine.

[0025] On the other hand, if the processing circuit 131 determines in the processing of step S200 that the estimated temperature Thest is equal to or greater than the threshold value Thth (step S200: YES), the processing circuit 131 proceeds to the processing of step S210. Then, in the processing of step S210, the processing circuit 131 determines whether the vehicle speed SPD is less than the determination vehicle speed SPDth. Note that the magnitude of the determination vehicle speed SPDth is set so that it can be determined that there is almost no airflow due to traveling within the engine compartment 110, based on the vehicle speed SPD being less than the determination vehicle speed SPDth. For example, the determination vehicle speed SPDth is 10 kilometers per hour. Note that the determination vehicle speed SPDth may be a value smaller than 10 kilometers per hour. For example, it may be 1 kilometer per hour.

[0026] If the processing circuit 131 determines in the processing of step S210 that the vehicle speed SPD is equal to or greater than the determination vehicle speed SPDth (step S210: NO), the processing circuit 131 proceeds to step S240. Then, the processing circuit 131 temporarily ends this routine. On the other hand, if the processing circuit 131 determines in the processing of step S210 that the vehicle speed SPD is less than the determination vehicle speed SPDth (step S210: YES), the processing circuit 131 proceeds to step S220. Then, in the processing of step S220, the processing circuit 131 determines whether or not there is an abnormality in the exhaust temperature sensor 200. If there is no exhaust temperature signal output from the exhaust temperature sensor 200 or if the exhaust temperature signal is outside the normal range, the processing circuit 131 determines that there is an abnormality in the exhaust temperature sensor 200. If there is no abnormality in the exhaust temperature sensor 200, the processing circuit 131 determines that there is no abnormality in the exhaust temperature sensor 200. If the processing circuit 131 determines in step S220 that the exhaust temperature sensor 200 is abnormal (step S220: NO), the processing circuit 131 proceeds to step S240. Then, the processing circuit 131 temporarily ends this routine. On the other hand, if the processing circuit 131 determines in step S220 that the exhaust temperature sensor 200 is not abnormal (step S220: YES), the processing circuit 131 proceeds to step S230. Then, in step S230, the processing circuit 131 sets the overheat condition flag to "1."

[0027] In the next step S250, the processing circuit 131 determines whether the voltage Vb is equal to or greater than the drive lower limit Vbth. The drive lower limit Vbth is set to a value such that, based on whether the voltage Vb is equal to or greater than the drive lower limit Vbth, it can be determined that the various components of the vehicle 100 can be stably driven even if the drive of the electric fan 43 is started. If the processing circuit 131 determines in step S250 that the voltage Vb is equal to or greater than the drive lower limit Vbth (step S250: YES), the processing circuit 131 proceeds to step S260. Then, in step S260, the processing circuit 131 sets the drive request flag to "1." If the drive request flag is "1," the processing circuit 131 determines that execution of the air blowing process is requested and drives the electric fan 43. That is, the air blowing process is started. At this time, the processing circuit 131 operates the electric fan 43 at a rotation speed that can sufficiently cool the exhaust temperature sensor 200, regardless of the water temperature THW. After executing the process of step S260 in this way, the processing circuit 131 temporarily ends this routine. On the other hand, if the processing circuit 131 determines in the process of step S250 that the voltage Vb is less than the drive lower limit Vbth (step S250: NO), it temporarily ends this routine without executing the process of step S260. That is, in this case, the processing circuit 131 does not execute the air blowing process.

[0028] 6 shows the flow of processing in a routine for ending the air blowing process. This routine is repeatedly executed by the processing circuit 131 while the vehicle control device 130 is operating. When starting this routine, the processing circuit 131 first determines in step S300 whether the timing has come when the overheat condition flag has been changed from "0" to "1." Specifically, when both of the following two conditions are met, it determines that the timing has come when the overheat condition flag has been changed from "0" to "1."

[0029] The current overheat condition flag is "1". The overheat condition flag was "0" the last time S300 was executed. If the processing circuit 131 determines in the process of step S300 that the timing has come when the overheat condition flag has been changed from "0" to "1" (step S300: YES), the processing circuit 131 proceeds to the process of step S310. In the process of step S310, the processing circuit 131 resets the counter CNT to "0". The counter CNT is a counter for measuring the time during which the electric fan 43 is operated by the air blowing process. Next, the processing circuit 131 determines a stop threshold CNTth. The stop threshold CNTth is ventilation This value determines the length of the period during which the electric fan 43 is operated by the process. In the process of step S340 described later, the processing circuit 131 determines whether the counter CNT has reached the stop threshold CNTth. ventilation The processing circuit 131 sets the stop threshold CNTth to a larger value in the processing of step S320 as the estimated temperature Thest when the affirmative determination is made in the processing of step S300 is higher.

[0030] The processing circuit 131 counts up the counter CNT in the next step S330. Then, the processing circuit 131 proceeds to step S340. In step S340, the processing circuit 131 determines whether a stop condition is met. The stop condition is determined to be met when either of the following two conditions is met:

[0031] The counter CNT is equal to or greater than the stop threshold CNTth. The voltage Vb remains below the lower limit for a specified period of time. The continuation lower limit is a value smaller than the drive lower limit Vbth. If the processing circuit 131 determines in the process of step S340 that the stop condition is met (step S340: YES), the processing circuit 131 proceeds to the process of step S350. Then, in the process of step S350, the processing circuit 131 changes the drive request flag to "0" to stop the operation of the electric fan 43. That is, in the process of step S350, the processing circuit 131 ventilation The processing circuit 131 stops the processing. ventilation When the processing is stopped, the counter CNT and the stop threshold CNTth are reset, and the processing circuit 131 temporarily ends this routine.

[0032] If the processing circuit 131 determines in the processing of step S300 that the timing has not yet come when the overheat condition flag has been changed from "0" to "1" (step S300: NO), it proceeds to step S330 without executing the processing of steps S310 and S320. Then, the processing circuit 131 counts up the counter CNT through the processing of step S330 and proceeds to step S340. If the processing circuit 131 determines in the processing of step S340 that the stop condition is not satisfied (step S340: NO), it temporarily ends this routine without executing the processing of step S350.

[0033] <Operation of this embodiment> When the estimated temperature Thest when the vehicle speed SPD becomes less than the determination vehicle speed SPDth is equal to or greater than the threshold value Thth, the vehicle control device 130 ventilation The process is executed to drive the electric fan 43. This draws outside air into the engine compartment 110. As a result, the part of the exhaust temperature sensor 200 exposed to the outside of the exhaust pipe 17 is cooled by the outside air drawn into the engine compartment 110. Even if the vehicle speed SPD decreases and the temperature of the part of the exhaust temperature sensor 200 exposed to the outside of the exhaust pipe 17 begins to rise, if the temperatures of the exhaust pipe 17 and the exhaust temperature sensor 200 are low at that time, the temperature rise due to heat transfer will be small. Therefore, if the temperature of the exhaust temperature sensor 200 is low, the temperature of the bushing 250 will not rise excessively even if the electric fan 43 is not driven. If the estimated temperature Thest when the vehicle speed SPD becomes less than the judgment vehicle speed SPDth is equal to or higher than the threshold value Thth, the vehicle control device 130 ventilation Therefore, the vehicle control device 130 can prevent the electric fan 43 from being driven unnecessarily.

[0034] <Effects of this embodiment> (1) The vehicle control device 130 can prevent the electric fan 43 from being driven unnecessarily and can also prevent the bushing 250 of the exhaust temperature sensor 200 from overheating.

[0035] (2) The exhaust temperature sensor 200 is heated by heat transferred from the exhaust pipe 17, which is heated by the exhaust gas flowing through the exhaust pipe 17. Therefore, the temperature of the exhaust temperature sensor 200 changes with a first-order lag element relative to the exhaust temperature Thex. Furthermore, the greater the exhaust flow rate, the more quickly the temperature of the exhaust temperature sensor 200 converges to the exhaust temperature Thex. The vehicle control device 130 calculates the estimated temperature Thest by applying first-order lag processing to the corrected base value Thbsc using a smaller time constant τ as the exhaust flow rate increases. In this way, the vehicle control device 130 can calculate the estimated temperature Thest that reflects the effects of changes in the exhaust flow rate.

[0036] (3) The higher the vehicle speed SPD, the more easily the exhaust temperature sensor 200 is cooled by the wind while traveling. The vehicle control device 130 calculates the corrected base value Thbsc by correcting the temperature base value Thbs by subtracting a larger value as the vehicle speed SPD increases. In this way, the vehicle control device 130 calculates the corrected base value Thbsc that reflects the influence of cooling due to the wind while traveling. In other words, the vehicle control device 130 can calculate the estimated temperature Thest by reflecting the influence of changes in the exhaust flow rate and the influence of cooling due to the wind while traveling.

[0037] (4) The threaded portion 230 of the exhaust temperature sensor 200, which is fastened to the mounting boss 171 of the exhaust pipe 17, is in contact with the exhaust pipe 17 and is the portion that serves as the starting point for heat transfer from the exhaust pipe 17. It can be estimated that the higher the temperature of the threaded portion 230, the greater the amount of heat stored in the exhaust pipe 17. Therefore, it can be estimated that the higher the temperature of the threaded portion 230, the more likely the temperature of the portion of the exhaust temperature sensor 200 that is exposed to the outside of the exhaust pipe 17 is to rise due to heat transfer. The vehicle control device 130 calculates the temperature of the threaded portion 230, which is the starting point for heat transfer from the exhaust pipe 17, as the estimated temperature Thest. This allows the vehicle control device 130 to appropriately control the electric fan 43 based on the estimated temperature Thest.

[0038] (5) If the condition for stopping the electric fan 43 is that the vehicle speed SPD is equal to or greater than the threshold vehicle speed SPDth, the electric fan 43 will repeatedly start and stop when the vehicle repeatedly stops and starts. In this case, sufficient cooling is not performed, and the temperature of the portion of the exhaust temperature sensor 200 exposed to the outside of the exhaust pipe 17 may continue to rise due to heat transfer from the exhaust pipe 17. Furthermore, repeated operation and stop in short cycles may cause battery degradation. In response to this, the vehicle control device 130 stops the electric fan 43 in the air blowing process when the counter CNT reaches the stop threshold CNTth. Therefore, the vehicle control device 130 can prevent the electric fan 43 from repeatedly starting and stopping in short cycles.

[0039] (6) It can be estimated that the amount of heat stored in the exhaust pipe 17 increases as the estimated temperature Thest when it is determined that the estimated temperature Thest when the vehicle speed SPD becomes less than the determination vehicle speed SPDth is equal to or greater than the threshold value Thth. Therefore, the vehicle control device 130 sets the stop threshold value CNTth to a larger value as the estimated temperature Thest when it is determined that the estimated temperature Thest when the vehicle speed SPD becomes less than the determination vehicle speed SPDth is equal to or greater than the threshold value Thth. As a result, the vehicle control device 130 operates the electric fan 43 for a longer period of time when a larger amount of heat has been stored in the exhaust pipe 17 and it is necessary to continue operating the electric fan 43 for sufficient cooling. In other words, the vehicle control device 130 can control the operating period appropriately as needed.

[0040] <Example of change> This embodiment can be modified as follows: This embodiment and the following modifications can be combined and implemented within the scope of technical compatibility.

[0041] Although an example has been given in which the temperature of the threaded portion 230 is estimated as the estimated temperature Thest, the vehicle control device 130 may estimate the temperature of a portion of the exhaust temperature sensor 200 other than the threaded portion 230 as the estimated temperature Thest.

[0042] -Prevents Busch 250 from overheating ventilation However, the vehicle control device 130 may also perform other processes to prevent overheating of other parts of the exhaust temperature sensor 200 that are exposed to the outside of the exhaust pipe 17. ventilation It may also be something that executes processing.

[0043] The process of S220 may be omitted. That is, the fact that the exhaust temperature sensor 200 is normal does not have to be included in the conditions for performing the air blowing process. · ventilation The conditions for stopping the process can be changed as needed. For example, you can always stop the process after a certain period of time has elapsed. ventilation The process may be stopped when it is determined that the vehicle 100 has started to move. ventilation The processing may be stopped.

[0044] In the above embodiment, the vehicle control device 130 includes a processing circuit 131 and a storage device 132 and executes software processing. However, this is merely an example. For example, the vehicle control device 130 may include a dedicated hardware circuit (e.g., an ASIC) that processes at least part of the software processing executed in the above embodiment. That is, the vehicle control device 130 may have any of the following configurations (a) to (c): (a) The vehicle control device 130 includes an execution device that executes all processing in accordance with a program and a storage device that stores the program. That is, the vehicle control device 130 includes a software execution device. (b) The vehicle control device 130 includes an execution device that executes part of the processing in accordance with a program and a storage device. Furthermore, the vehicle control device 130 includes a dedicated hardware circuit that executes the remaining processing. (c) The vehicle control device 130 includes a dedicated hardware circuit that executes all processing. Here, there may be multiple software execution devices and / or dedicated hardware circuits. That is, the above processing may be executed by a processing circuitry that includes at least one of one or more software execution devices and one or more dedicated hardware circuits. The storage devices or computer-readable media for storing the programs include any available media that can be accessed by a general purpose or special purpose computer. [Explanation of symbols]

[0045] 10...engine, 17...exhaust pipe, 100...vehicle, 110...engine compartment, 120...front grille, 130...vehicle control device, 131...processing circuit, 132...storage device, 140...vehicle speed sensor, 141...voltage sensor, 171...mounting boss, 200...exhaust temperature sensor, 230...thread portion, 250...bush

Claims

1. A vehicle control device that controls an electric fan that draws outside air into the engine compartment. The exhaust temperature detected by the exhaust temperature sensor attached to the exhaust pipe of the engine and the vehicle speed detected by the vehicle speed sensor are acquired. a temperature estimation process for calculating an estimated temperature of a specific portion of the exhaust temperature sensor based on the exhaust temperature and the vehicle speed; a blowing process for operating the electric fan when the estimated temperature when the vehicle speed becomes less than a threshold value is equal to or higher than a threshold value; A vehicle control device comprising a processing circuit that executes the above.

2. In the temperature estimation process, the processing circuit calculates a corrected base value by applying a correction to a temperature base value calculated based on the exhaust temperature by subtracting a larger value as the vehicle speed increases, and calculates the estimated temperature by applying a first-order lag process to the corrected base value using a smaller time constant as the exhaust flow rate increases. The vehicle control device according to claim 1 .

3. In the temperature estimation process, the processing circuit calculates, as the estimated temperature, the temperature of a threaded portion of the exhaust temperature sensor that is fastened to a mounting boss of the exhaust pipe. The vehicle control device according to claim 1 .

4. In the air blowing process, the processing circuit counts up a counter as time passes after the electric fan starts operating, and stops the electric fan when the counter reaches a stop threshold. The vehicle control device according to claim 1 .

5. The processing circuit sets the stop threshold to a larger value as the estimated temperature when it is determined that the estimated temperature when the vehicle speed becomes less than the determination vehicle speed is equal to or higher than the threshold. The vehicle control device according to claim 4.

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