Vehicle control system

Abstract

To provide a vehicle control device that can efficiently cool the control unit while preventing increased costs due to the provision of a dedicated cooling structure. [Solution] A control device for a vehicle equipped with an engine, comprising: a cooling fan that generates an airflow to promote the cooling of the coolant that cools the engine; a control unit located near the engine and within the region of the airflow generated by the cooling fan, capable of controlling the rotation speed of the cooling fan; and a temperature detection unit that detects the temperature of the control unit, wherein the control unit performs control unit cooling control, which controls the rotation speed of the cooling fan according to the temperature when the temperature detected by the temperature detection unit becomes higher than a preset first temperature.

Description

Technical Field

[0001] The present disclosure relates to a control device for a vehicle.

Background Art

[0002] A vehicle equipped with an engine has a cooling circuit that cools each part of the engine with cooling water (see Patent Document 1). The cooling circuit absorbs heat by circulating the cooling water into the engine with a water pump, and dissipates heat with a radiator disposed outside the engine. A cooling fan is provided near the radiator, and the heat dissipation at the radiator is promoted by the air flow generated by the cooling fan.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, a control unit (e.g., ECU) that performs various controls of a vehicle may be provided near the engine due to the layout of other devices.

[0005] In a vehicle equipped with an engine, for example, a diesel engine, the surrounding of the engine becomes relatively high temperature during DPF (Diesel Particulate Filter) regeneration while the vehicle is stopped or during idling after a large load is applied to the engine, and peripheral devices including the control unit may be exposed to high temperature. Also, the control unit itself generates heat according to the processing load. Therefore, in order to maintain the control unit at an appropriate temperature specification, a cooling module for water-cooling the control unit may be added.

[0006] However, adding an additional cooling module for the control unit would complicate the engine's surrounding configuration and lead to increased costs due to the increased number of parts.

[0007] Therefore, the purpose of this disclosure is to provide a vehicle control device that can efficiently cool the control unit while preventing increased costs due to the provision of a dedicated cooling structure. [Means for solving the problem]

[0008] This disclosure is made to solve at least some of the aforementioned problems and can be implemented in the following forms or applications.

[0009] (1) The vehicle control device according to this application example is a vehicle control device equipped with an engine, comprising: a cooling fan that generates an airflow to promote the cooling of the coolant that cools the engine; a control unit located near the engine and in the region of the airflow generated by the cooling fan, which is capable of controlling the rotation speed of the cooling fan; and a temperature detection unit that detects the temperature of the control unit, wherein the control unit performs control unit cooling control, which controls the rotation speed of the cooling fan according to the temperature when the temperature detected by the temperature detection unit becomes higher than a preset first temperature.

[0010] According to this application example, when the temperature detected by the temperature detection unit rises above the first temperature, the rotation speed of the cooling fan is controlled according to the temperature, thereby lowering the temperature of the control unit with the airflow generated by the cooling fan. In other words, the control unit can be maintained at an appropriate temperature without adding a separate cooling module to cool the control unit. This allows for efficient cooling of the control unit while preventing increased costs associated with providing a dedicated cooling structure.

[0011] (2) A vehicle control device according to the application example of (1) above, further comprising a coupling portion capable of adjusting the rotational speed of the cooling fan by adjusting the rotational driving force transmitted from the engine to the cooling fan, wherein the control unit controls the cooling of the control unit by increasing the rotational driving force transmitted from the engine to the cooling fan via the coupling portion when the vehicle is running.

[0012] According to this application example, when the vehicle is in motion, the rotation speed of the cooling fan is adjusted by the coupling, thereby adjusting the airflow generated by the cooling fan. This allows for efficient cooling of the control unit while the vehicle is in motion.

[0013] (3) A vehicle control device according to the application example of (1) above, further comprising a coupling portion capable of adjusting the rotational speed of the cooling fan by adjusting the rotational driving force transmitted from the engine to the cooling fan, wherein the control unit is configured such that, when the vehicle is stopped, the rotational driving force is directly transmitted from the engine to the cooling fan via the coupling portion, and the control unit performs cooling control by increasing the engine speed of the vehicle.

[0014] In this application example, when the vehicle is stationary, the rotational driving force from the engine is directly transmitted to the cooling fan, and the engine speed is changed by controlling the engine's fuel injection amount, etc., to adjust the airflow generated by the cooling fan. This allows for efficient cooling of the control unit when the vehicle is stationary. [Brief explanation of the drawing]

[0015] [Figure 1] This is a plan view showing the schematic configuration of the vehicle control device according to this embodiment. [Figure 2] This is a left side view showing a schematic configuration of the vehicle control device according to this embodiment. [Figure 3] This flowchart shows the control procedure during driving in the vehicle control device according to this embodiment. [Figure 4]This timing chart shows the time series of temperatures and clutch engagement status during driving. [Figure 5] This flowchart shows the control procedure when the vehicle is stopped in the control device of the vehicle according to this embodiment. [Figure 6] This timing chart shows the time series of various temperatures, clutch engagement status, and engine speed while the vehicle is stationary. [Modes for carrying out the invention]

[0016] The embodiment will be described below with reference to the drawings. This disclosure is not limited to the content described below, and can be modified and implemented as such without altering its essence. Furthermore, the drawings used in describing the embodiment are schematic representations of the components, and may be partially emphasized, enlarged, reduced, or omitted to enhance understanding, and may not accurately represent the scale or shape of the components.

[0017] Figure 1 is a plan view showing a schematic configuration of the vehicle control device according to this embodiment. Figure 2 is a left side view showing a schematic configuration of the vehicle control device according to this embodiment. As shown in Figure 1, the vehicle 1 is equipped with an engine 10 (internal combustion engine) as a power source for driving. The vehicle 1 in this embodiment is a truck, and the engine 10 is a diesel engine equipped with fuel injectors (not shown) that inject fuel into each cylinder.

[0018] The engine 10 has an engine body 11 which includes cylinders and the like that form a combustion chamber, an intake pipe 13 connected to it via an intake manifold 12, and an exhaust pipe 15 connected to it via an exhaust manifold 14.

[0019] The engine 10 is connected to a cooling circuit 20 through which coolant circulates to cool the engine 10. The cooling circuit 20 is connected to a water pump 22 that drives the circulation of coolant via a coolant passage 21, a radiator 23 that cools the coolant by exchanging heat with the outside air, and the like. The coolant passage 21 is formed of a tubular member.

[0020] Further, a cooling fan 17 is connected to the engine 10 via a fan clutch 16 (joint part). The fan clutch 16 of the present embodiment is an electric joint means capable of adjusting the rotational speed of the cooling fan 17 by changing the degree of connection of the clutch by electronic control, thereby changing the rotational driving force transmitted from the engine 10 to the cooling fan 17.

[0021] The cooling fan 17 has a plurality of blades and is a rotating body that generates an air flow to promote the cooling of the cooling water. Specifically, the cooling fan 17 is disposed between the radiator 23 and the engine body 11. Then, the cooling fan 17 rotates by the driving force of the engine 10 transmitted via the fan clutch 16, sucks outside air, increases the amount of air passing through the radiator 23, and promotes the cooling of the cooling water in the radiator 23.

[0022] The vehicle 1 is also equipped with an ECU 40 (Electronic Control Unit), which is a computer that performs various controls on the vehicle 1. The ECU 40 is a control unit including a CPU (processor) that executes various programs, a memory (storage device) such as a ROM and a RAM that stores information such as programs and data, an interface that transmits and receives various information, and the like. The ECU 40 of the present embodiment is provided in the vicinity of the engine 10 in an area (white arrow W in FIGS. 1 and 2) where the air flow generated by the cooling fan 17 hits. Specifically, as shown in FIGS. 1 and 2, the ECU 40 is provided at the rear part of the left side surface of the engine 10.

[0023] As shown in Figure 1, the ECU 40 of this embodiment is electrically connected to the ECU temperature sensor 30 (temperature detection unit), engine speed sensor 31, outside air temperature sensor 32, coolant outlet temperature sensor 33, fan speed sensor 34, vehicle speed sensor 35, the aforementioned fan clutch 16, water pump 22, etc. However, the sensors and devices electrically connected to the ECU 40 are not limited to these, and for example, it may be connected to combustion-related sensors for controlling the fuel injection amount, fuel injection timing, etc., by the fuel injector.

[0024] As shown in Figure 2, the ECU temperature sensor 30 is provided in contact with the ECU 40 or incorporated inside the ECU 40, and has the function of detecting the ECU temperature of the ECU 40.

[0025] The engine speed sensor 31 is provided on the outer circumference of a flywheel (not shown) of the engine 10 and has the function of detecting the engine speed.

[0026] The outside air temperature sensor 32 is installed in a location that is exposed to the outside air, such as inside the front bumper of the vehicle 1, and has the function of detecting the outside air temperature around the vehicle 1.

[0027] The coolant outlet temperature sensor 33 is located near the confluence of the engine body 11 and the coolant passage 21, and has the function of detecting the coolant temperature of the coolant heated by the engine body 11.

[0028] The fan speed sensor 34 is installed on the cooling fan 17 and has the function of detecting the rotational speed of the cooling fan 17, which is rotated by the driving force of the engine 10.

[0029] The vehicle speed sensor 35 has the function of detecting the vehicle speed of vehicle 1, and can detect the vehicle speed from the rotational speed of the output shaft (e.g., propeller shaft) of vehicle 1.

[0030] In this embodiment, the ECU 40 performs ECU cooling control (control unit cooling control) to efficiently cool the ECU 40 when it becomes hot while the vehicle 1 is running and when it is stopped. Specifically, in the ECU cooling control, the ECU 40 mainly controls the rotation speed of the cooling fan 17. More specifically, when the vehicle 1 is running, the ECU 40 performs ECU cooling control by controlling the temperature of the coolant using the cooling circuit 20 and the cooling fan 17, and by changing the degree of clutch engagement with the fan clutch 16. Also, when the vehicle 1 is stopped, the ECU 40 performs ECU cooling control by changing the engine speed of the engine 10.

[0031] Figure 3 is a flowchart showing the control procedure in the control device of vehicle 1 during driving, and Figure 4 is a timing chart showing the time series of (a) each temperature and (b) clutch engagement state during driving in this embodiment. Figure 5 is a flowchart showing the control procedure in the control device of vehicle 1 when stopped, and Figure 6 is a timing chart showing the time series of (a) each temperature, (b) clutch engagement state and (c) engine speed when stopped in this embodiment.

[0032] First, following the flowchart in Figure 3 and referring to the timing chart in Figure 4, we will explain the ECU cooling control performed by the ECU 40 of vehicle 1. Note that the ECU cooling control shown in the flowchart in Figure 3 is performed when vehicle 1 is in motion, that is, when the ECU 40 detects a vehicle speed greater than 0 km / h using the vehicle speed sensor 35.

[0033] In Step S100, the ECU 40 obtains the ECU temperature (Td) from the ECU temperature sensor 30.

[0034] In step S101, the ECU 40 determines whether the ECU temperature (Td) obtained by the ECU temperature sensor 30 is equal to or greater than a preset first temperature (T1). The first temperature is the temperature at which the ECU 40 starts ECU cooling control to cool itself (control start temperature). The ECU 40 has a specified allowable temperature (second temperature, described later) that corresponds to the operating limit temperature, and for example, the first temperature is set to 80% of the allowable temperature. Note that the setting of the first temperature is not limited to this and may vary depending on the state of the ECU 40.

[0035] If the result of step S101 is false (No), that is, if the ECU temperature (Td) is less than the first temperature (T1), the ECU 40 proceeds to step S102.

[0036] In step S102, the ECU 40 performs normal engine cooling fan 17 control (hereinafter referred to as water temperature control) and returns to the flowchart. Specifically, as water temperature control, the ECU 40 adjusts the degree of engagement of the fan clutch 16 and determines the rotation speed of the cooling fan 17 based on the engine speed detected by the engine speed sensor 31, the coolant temperature coming out of the engine 10 detected by the coolant outlet temperature sensor 33, and a water temperature control map corresponding to the fuel injection amount. For example, at time A in Figure 4, the ECU 40 starts engaging the fan clutch 16 when the coolant temperature exceeds a predetermined water temperature. On the other hand, until time A in Figure 4, when the coolant temperature is below the predetermined water temperature, the fan clutch 16 is shut off and the cooling fan 17 is not rotated. Note that the water temperature control performed by the ECU 40 is not limited to this.

[0037] On the other hand, if the result of step S101 is true (Yes), that is, if the ECU temperature (Td) is equal to or greater than the first temperature (T1), the ECU 40 proceeds to step S103.

[0038] In step S103, the ECU 40 determines whether the ECU temperature (Td) is equal to or greater than a preset second temperature (T2). The second temperature is set to the allowable temperature of the ECU 40. If the result of this determination is false (No), that is, if the ECU temperature (Td) is less than the second temperature (T2), the ECU 40 proceeds to step S104.

[0039] In step S104, the ECU 40 calculates the rate of temperature rise per predetermined time t of the ECU temperature (Td) detected by the ECU temperature sensor 30. Specifically, the ECU 40 stores the initial ECU temperature (Td1) at the start of processing in step S104, and when the timer built into the ECU 40 detects that a predetermined time t has elapsed, it obtains the final ECU temperature (Td2) from the ECU temperature sensor 30 again and calculates the rate of temperature rise (Td2-Td1) / t from the initial ECU temperature (Td1) to the final ECU temperature (Td2).

[0040] In the next step S105, the ECU40 estimates the cumulative amount of air cooling per predetermined time t for the ECU40. The cumulative amount of air cooling in this embodiment is the air cooling power for the ECU40 and is calculated according to the rotational speed of the cooling fan 17 detected by the fan rotational speed sensor 34 and the predetermined time t measured by the timer of the ECU40. Specifically, the cumulative amount of air cooling is calculated by accumulating the rotational speed of the cooling fan 17 over the predetermined time t (cumulative amount of air cooling = Σ rotational speed of the cooling fan 17). In other words, the greater the cumulative amount of air cooling, the stronger the cooling of the ECU40.

[0041] In step S106, the ECU 40 corrects the degree of connection of the fan clutch 16 based on the rate of rise in ECU temperature and the cumulative amount of air cooling, controls the connection, and returns the flowchart.

[0042] The correction amount for the fan clutch 16 here is set so that the degree of engagement of the fan clutch 16 increases as the value increases. Specifically, the ECU 40 uses the degree of engagement of the fan clutch 16 based on the water temperature control map in water temperature control as a reference, and increases the correction amount as the rate of temperature rise increases and the amount of accumulated air cooling decreases, thereby increasing the degree of engagement of the fan clutch 16.

[0043] Specifically, as shown in Table 1 below, the correction amount is set to four levels: no correction, first correction amount, second correction amount greater than the first correction amount, and third correction amount greater than the second correction amount. When the temperature rise rate is 0 or less, no correction is applied regardless of the cumulative amount of air cooling. When the temperature rise rate is relatively low, from 0 to a predetermined rate, the first correction amount is applied if the cumulative amount of air cooling is a relatively large amount greater than or equal to a predetermined amount, and the second correction amount is applied if the cumulative amount of air cooling is a relatively small amount less than the predetermined amount. Furthermore, when the temperature rise rate is relatively high, greater than or equal to a predetermined rate, the second correction amount is applied if the cumulative amount of air cooling is a relatively large amount, and the third correction amount is applied if the cumulative amount of air cooling is a relatively small amount. [Table 1]

[0044] The ECU cooling control from steps S104 to S106 is the control performed between time point B and time point C, and between time point D and time point E, in Figure 4.

[0045] On the other hand, if the result of the determination in step S103 is true (Yes), that is, if the ECU temperature (Td) is equal to or greater than the second temperature (T2), which is the allowable temperature, the ECU 40 proceeds to step S107.

[0046] In step S107, the ECU 40 controls the degree of engagement of the fan clutch 16 to a state in which rotational driving force is directly transmitted from the engine 10 to the cooling fan 17, and returns to the flowchart. In other words, if the ECU temperature (Td) exceeds the allowable temperature, the ECU 40 locks the fan clutch 16 and rotates the cooling fan 17 at its maximum speed to cool the ECU 40. This ECU cooling control in step S107 is performed between time C and time D in Figure 4.

[0047] Thus, when vehicle 1 is in motion, the ECU cooling control is performed by correcting the degree of engagement of the fan clutch 16, since the engine speed is determined according to the driving conditions.

[0048] Next, following the flowchart in Figure 5 and referring to the timing chart in Figure 6, we will explain the ECU cooling control performed by the ECU 40 of vehicle 1. Note that the ECU cooling control shown in the flowchart in Figure 5 is performed when vehicle 1 is stationary, that is, when the ECU 40 detects a vehicle speed of 0 km / h or less using the vehicle speed sensor 35.

[0049] In Step S200, the ECU 40 obtains its temperature (Td) from the ECU temperature sensor 30.

[0050] In step S201, the ECU 40 determines whether the ECU temperature (Td) obtained by the ECU temperature sensor 30 is equal to or greater than a preset first temperature (T1). If the result of this determination is false (No), that is, if the ECU temperature is less than the first temperature, the ECU 40 proceeds to step S202.

[0051] In step S202, the ECU 40 performs normal idle control and returns to the flowchart. Normal idle control involves controlling the fuel injection amount and timing based on a pre-set idle control map to achieve the target engine speed (also called the target idle speed) during idling. For example, in Figure 6, the ECU 40 performs normal idle control up to point A and from point D onward.

[0052] On the other hand, if the result of step S201 is true (Yes), that is, if the ECU temperature (Td) is equal to or greater than the first temperature (T1), the ECU 40 proceeds to step S203.

[0053] In step S203, the ECU 40 controls the degree of engagement of the fan clutch 16 to a state in which rotational driving force is directly transmitted from the engine 10 to the cooling fan 17 (point A in Figure 6).

[0054] In the next step S204, the ECU 40 determines whether the ECU temperature (Td) is equal to or greater than a preset second temperature (T2). If the result of this determination is false (No), that is, if the ECU temperature (Td) is less than the second temperature (T2), the ECU 40 proceeds to step S205.

[0055] In step S205, the ECU 40 calculates the temperature rise rate per predetermined time t of the ECU temperature (Td) detected by the ECU temperature sensor 30. The calculation of the temperature rise rate is the same as in step S104 described above.

[0056] In the next step, S206, the ECU40 calculates the cumulative amount of air cooling over a predetermined time t. The calculation of the cumulative amount of air cooling is the same as in step S105 described above.

[0057] In step S207, the ECU40 corrects the target idling speed based on the rate of increase in ECU temperature and the cumulative amount of air cooling, and controls the engine speed (specifically, it controls the fuel injection amount and fuel injection timing), and returns to the flowchart.

[0058] The correction amount for the target idle speed here is set so that the larger the value, the higher the target idle speed. Specifically, the ECU40 uses the target idle speed based on the idle control map in normal idle control as a reference, and increases the correction amount as the temperature rise rate is higher and the cumulative amount of air cooling is lower, thereby raising the target idle speed.

[0059] Specifically, as shown in Table 2 below, the correction amount is set to four levels: no correction, first correction amount, second correction amount greater than the first correction amount, and third correction amount greater than the second correction amount. When the temperature rise rate is 0 or less, no correction is applied regardless of the cumulative amount of air cooling. When the temperature rise rate is relatively low, from 0 to a predetermined rate, the first correction amount is applied if the cumulative amount of air cooling is a relatively large amount equal to or greater than a predetermined amount, and the second correction amount is applied if the cumulative amount of air cooling is a relatively small amount less than a predetermined amount. Furthermore, when the temperature rise rate is relatively high, equal to or greater than a predetermined rate, the second correction amount is applied if the cumulative amount of air cooling is a relatively large amount, and the third correction amount is applied if the cumulative amount of air cooling is a relatively small amount. [Table 2]

[0060] The ECU cooling control from steps S205 to S207 is the control performed between time A and time B, and between time C and time D, in Figure 6.

[0061] On the other hand, if the result of the determination in step S204 is true (Yes), that is, if the ECU temperature (Td) is equal to or greater than the second temperature (T2), the ECU 40 proceeds to step S208.

[0062] In step S208, the ECU 40 controls the fuel injection amount and other parameters so that the target idling speed becomes the maximum speed (maximum idling speed) in the idling control map, and returns the flowchart. This ECU cooling control in step S208 is performed between time point B and time point C in Figure 6.

[0063] Thus, when vehicle 1 is stopped, the ECU cooling control is performed by fully engaging the fan clutch 16 and controlling the cooling of the ECU 40 according to the engine speed.

[0064] In the control device of the vehicle 1 according to this embodiment, when the ECU temperature detected by the ECU temperature sensor 30 rises above the first temperature, the rotation speed of the cooling fan 17 is controlled according to the ECU temperature, thereby lowering the temperature of the ECU 40 with the airflow generated by the cooling fan 17. In other words, the ECU 40 can be maintained at an appropriate temperature without adding a separate cooling module to cool the ECU 40. This allows for efficient cooling of the ECU 40 while preventing increased costs due to the provision of a dedicated cooling structure.

[0065] Furthermore, in this embodiment, the ECU 40 adjusts the airflow generated by the cooling fan 17 by adjusting the degree of engagement of the fan clutch 16 when the vehicle 1 is running. This allows for efficient cooling of the ECU 40 while the vehicle is running.

[0066] Furthermore, in this embodiment, when the vehicle 1 is stopped, the ECU 40 transmits the rotational driving force from the engine 10 directly to the cooling fan 17, and adjusts the airflow generated by the cooling fan 17 by changing the engine speed by controlling the fuel injection amount of the engine 10, etc. This enables efficient cooling of the ECU 40 when the vehicle is stopped.

[0067] This concludes the description of embodiments of the present invention, but the forms of the present invention are not limited to these embodiments.

[0068] In the above embodiment, vehicle 1 is a truck and engine 10 is a diesel engine, but the type of vehicle and engine are not limited to these. For example, the vehicle may be a passenger car, and the engine may be a gasoline engine, etc.

[0069] In the above embodiment, the first and second temperatures are set to the same value for ECU control during vehicle operation and ECU control when the vehicle is stopped, but they may be set to different values. [Explanation of Symbols]

[0070] 1 vehicle 10 Engines 11. Engine body 12 Intake Manifold 13 Intake pipe 14 Exhaust Manifold 15 Exhaust pipe 16 Fan Clutch 17 Cooling fan 20 Cooling circuit 21 Cooling water passage 22 Water pump 23 Radiator 30 ECU Temperature Sensor 31. Engine speed sensor 32. Outdoor temperature sensor 33 Cooling water outlet temperature sensor 34. Fan speed sensor 35. Vehicle speed sensor 40 Control Units

Claims

1. A control device for a vehicle equipped with an engine, A cooling fan that generates an airflow to promote the cooling of the coolant that cools the engine, A control unit is provided near the engine and in the region of the airflow generated by the cooling fan, and is capable of controlling the rotational speed of the cooling fan. The control unit includes a temperature detection unit for detecting the temperature of the control unit, The control unit performs cooling control, which controls the rotation speed of the cooling fan according to the temperature detected by the temperature detection unit when the temperature exceeds a preset first temperature. A vehicle control device characterized by the following features.

2. The coupling portion has a mechanism that allows the rotational speed of the cooling fan to be adjusted by adjusting the rotational driving force transmitted from the engine to the cooling fan. The control unit performs cooling control by increasing the rotational driving force transmitted from the engine to the cooling fan via the coupling when the vehicle is in motion. The vehicle control device according to claim 1.

3. The coupling portion has a mechanism that allows the rotational speed of the cooling fan to be adjusted by adjusting the rotational driving force transmitted from the engine to the cooling fan. When the vehicle is stopped, the control unit is configured such that rotational driving force is directly transmitted from the engine to the cooling fan via the coupling, and the engine speed of the vehicle is increased to control the cooling of the control unit. The vehicle control device according to claim 1.

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