Vehicle control system

Abstract

The objective is to provide a vehicle control system that suppresses engine overheating. [Solution] A vehicle control device comprising: an acquisition unit that acquires location information of a vehicle equipped with an engine; a prediction unit that predicts whether or not the high-load operation of the engine will continue for a predetermined time or longer based on the location information; and a flow rate control unit that, when it is predicted that the high-load operation of the engine will continue for a predetermined time or longer, increases the flow rate of high-temperature coolant flowing through the engine to the radiator compared to when it is not predicted that the high-load operation of the engine will continue for a predetermined time or longer.

Description

Technical Field

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

Background Art

[0002] When the temperature of the cooling water becomes higher than a predetermined temperature due to the continuation of high-load operation of the engine, the flow rate of the cooling water flowing into the radiator is increased (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above technology, the flow rate of the cooling water flowing into the radiator is increased after the engine has already become high in temperature. Therefore, the temperature rise of the engine cannot be sufficiently suppressed, and there is a risk that the engine will overheat.

[0005] Therefore, an object of the present invention is to provide a vehicle control device in which engine overheating is suppressed.

Means for Solving the Problems

[0006] The above object can be achieved by a vehicle control device including an acquisition unit that acquires position information of a vehicle equipped with an engine, a prediction unit that predicts whether or not high-load operation of the engine will continue for a predetermined time or more based on the position information, and a flow rate control unit that increases the flow rate of high-temperature cooling water flowing through the engine to the radiator when it is predicted that the high-load operation of the engine will continue for the predetermined time or more, compared to when it is not predicted that the high-load operation of the engine will continue for the predetermined time or more.

[0007] The system may include a heat exchange amount control unit that increases the amount of heat exchange between the air conditioning refrigerant and the low-temperature cooling water flowing through the engine's intercooler and turbocharger in a heat exchanger, compared to when it is not expected that the high-load operation of the engine will continue for a predetermined time or longer.

[0008] The heat exchanger has a first passage through which the low-temperature cooling water flows, a second passage through which the refrigerant for air conditioning can flow, a third passage through which the refrigerant for air conditioning can flow and which is located closer to the first passage than the second passage, and a switching valve for flowing the refrigerant for air conditioning into the second passage or the third passage. The heat exchange amount control unit may increase the heat exchange amount by controlling the switching valve to flow the refrigerant for air conditioning into the second passage if it is not expected that the high-load operation of the engine will continue for a predetermined time or longer, and by controlling the switching valve to flow the refrigerant for air conditioning into the third passage if it is expected that the high-load operation of the engine will continue for a predetermined time or longer.

[0009] The system may include an ignition timing control unit that advances the ignition timing of the engine if it is predicted that the high-load operation of the engine will continue for a predetermined time or longer, compared to when it is not predicted that the high-load operation of the engine will continue for a predetermined time or longer.

[0010] The prediction unit may predict that the engine will continue operating under high load for a predetermined period of time or longer if the location information indicates that the vehicle is located on a circuit or gymkhana course. [Effects of the Invention]

[0011] According to the present invention, a vehicle control device can be provided that suppresses engine overheating. [Brief explanation of the drawing]

[0012] [Figure 1] This is a schematic diagram of the vehicle's configuration. [Figure 2]This is a schematic diagram of the high-temperature cooling circuit. [Figure 3] This graph shows the opening ratios of the flow paths adjusted by the multi-function valve. [Figure 4] This is a schematic diagram of the low-temperature cooling circuit and the air conditioning circuit. [Figure 5] This flowchart illustrates the overheat suppression control performed by the ECU. [Figure 6] This graph shows the relationship between ignition timing and the temperature of the high-temperature coolant immediately after it is discharged from the engine. [Modes for carrying out the invention]

[0013] [Vehicle Outline] Figure 1 is a schematic diagram of the vehicle 100. The vehicle 100 includes an engine 1, an intake passage 3, an exhaust passage 4, a supercharger 5, an intercooler 6, a catalytic converter 7a, a filter 7b, a bypass passage 8, a wastegate valve (hereinafter referred to as WGV) 9, an automatic transmission 21, a differential gear 23, wheels 25, and an ECU (Electronic Control Unit) 30. The engine 1 is a gasoline engine. The driving force of the engine 1 is transmitted to the wheels 25 via the automatic transmission 21 and the differential gear 23. The vehicle 100 is an engine-powered vehicle equipped with the engine 1 as a power source. However, it may also be a hybrid vehicle equipped with an electric motor in addition to the engine 1 as a power source.

[0014] Engine 1 has four cylinders 2, but the number of cylinders is not limited to this. Each cylinder 2 is equipped with a fuel injector 2a and a spark plug 2b. Engine 1 is connected to an intake passage 3 and an exhaust passage 4. A compressor 5b of the supercharger 5 is located in the middle of the intake passage 3. A turbine 5a of the supercharger 5 is located in the middle of the exhaust passage 4. The turbine 5a and the compressor 5b are coaxially connected by a shaft. The supercharger 5 supercharges the intake air into engine 1.

[0015] In the middle of the exhaust passage 4, there are provided a bypass passage 8 that bypasses the turbine 5a and a WGV 9 that opens and closes the bypass passage 8. The opening degree of the WGV 9 is adjusted by an electric actuator 9a that drives the WGV 9. The opening degree of the WGV 9 is feedback-controlled by the ECU 30 so as to become a target boost pressure determined according to the operating state of the engine 1. The ECU 30 outputs a command value to the electric actuator 9a to control the opening degree of the WGV 9. The WGV 9 is of a normally-closed type that is fully closed when the electric actuator 9a is de-energized.

[0016] Downstream of the compressor 5b in the intake passage 3, an intercooler 6 for cooling the intake air is arranged. Downstream of the intercooler 6 in the intake passage 3, a throttle valve 3a for adjusting the intake air amount of the engine 1 is arranged.

[0017] Downstream of the turbine 5a in the exhaust passage 4, a catalyst 7a for purifying the exhaust and a filter 7b for collecting exhaust particulate matter are provided. The filter ^{7b} is provided downstream of the catalyst 7a. The catalyst 7a contains, for example, catalyst metals such as platinum (Pt), palladium (Pd), and rhodium (Rh), has an oxygen storage capacity, and purifies NOx, HC, and CO. The filter 7b is a porous ceramic structure.

[0018] The ECU 30 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory). The ECU 30 controls the engine 1 according to a control program stored in advance in the ROM and based on information from sensors and information stored in the ROM in advance. The ECU 30 is an example of a vehicle control device. The ECU 30 realizes the overheat suppression control described later by functionally realizing an acquisition unit, a prediction unit, a flow rate control unit, a heat exchange amount control unit, and an ignition timing control unit.

[0019] The ECU 30 controls the operating state of the engine 1 based on the detection signals of various sensors such as the crank angle sensor 11, the air flow meter 12, the air-fuel ratio sensor 13, and the accelerator opening sensor 14. The crank angle sensor 11 detects the rotational angle of the crankshaft of the engine 1. The air flow meter 12 detects the amount of intake air inhaled into the intake passage 3. The air-fuel ratio sensor 13 detects the air-fuel ratio of the exhaust gas discharged from the engine 1. The accelerator opening sensor 14 detects the accelerator opening, which is the operation amount of the accelerator pedal.

[0020] Based on the output signals of various sensors, the ECU 30 grasps the engine speed and load of the engine 1. The ECU 30 outputs a command signal to various drive circuits connected to the output port according to the operating state thus grasped. Examples of the control performed by the ECU 30 in this way include throttle control for adjusting the opening of the throttle valve 3a, fuel injection control for adjusting the injection amount of the fuel injection valve 2a, and ignition timing control for adjusting the ignition timing of the ignition plug 2b.

[0021] In addition, a DCM (Data Communication Module) 32 as a wireless communication device is connected to the ECU 30. The DCM 32 acquires information of the driver's mobile terminal (for example, a smartphone) 34 via a communication network. Specifically, the mobile terminal 34 incorporates a GPS, and the DCM 32 acquires the position information of the mobile terminal 34 via the communication network. Thereby, the ECU 30 acquires the position information of the current vehicle 100. Also, the DCM 32 acquires map information around the current position of the vehicle 100 via the network. Note that the position information of the vehicle 100 and the map information around it acquired by the ECU 30 may be acquired from, for example, a car navigation equipped with a GPS.

[0022] [Schematic Configuration of High-Temperature Cooling Circuit] Figure 2 is a schematic diagram of the high-temperature cooling circuit 40. In the high-temperature cooling circuit 40, heat exchange takes place between the engine 1 and the high-temperature cooling water flowing inside the engine 1 to cool the engine 1. The high-temperature cooling circuit 40 includes a radiator 51, a reserve tank 52, a heater core 53, an ATF (Automatic Transmission Fluid) cooler 55, a throttle water jacket 56, a water pump 57, an oil cooler 58a, an exhaust cooling section 58b, and an inlet 59.

[0023] The water pump 57 is a mechanical pump that transports high-temperature coolant using the rotational power of the engine 1. A portion of the high-temperature coolant flows from the water pump 57 through the passage 48 to the cylinder block 1B, cylinder head 1A, and exhaust cooling section 58b of the engine 1. Another portion of the high-temperature coolant flows from the water pump 57 through the passage 47 to the oil cooler 58a and then to the exhaust cooling section 58b. The high-temperature coolant flows from the exhaust cooling section 58b through the passage 44 to the multi-function valve 50. The multi-function valve 50 is a four-way valve with passages 41, 43, 44, and 45 connected to it. The opening degrees of passages 41, 43, and 45 are changed according to the rotational angle position of the rotor of the multi-function valve 50, which will be described later. The rotor of the multi-function valve 50 is controlled by the ECU 30. More details will be provided later.

[0024] The flow path 41 is connected between the multi-function valve 50 and the inlet 59, with a radiator 51 located in between. Heat exchange takes place between the high-temperature coolant and the outside air in the radiator 51, promoting heat dissipation from the high-temperature coolant. The high-temperature coolant discharged from the radiator 51 is supplied to the inlet 59 via the flow path 41.

[0025] A channel 42 is provided, which branches off from channel 41 upstream of the radiator 51 and rejoins channel 41 downstream of the radiator 51. A reserve tank 52 is provided along channel 42.

[0026] The flow path 46 is connected to the multi-function valve 50 and the inlet 59, with a throttle water jacket 56 provided in between. The throttle water jacket 56 is located inside the throttle valve 3a. Heat exchange occurs between the high-temperature cooling water and the throttle valve 3a in the throttle water jacket 56, cooling the throttle valve 3a.

[0027] The flow path 43 is connected to the portion of the flow path 46 upstream of the throttle water jacket 56 and to the inlet 59. A heater core 53 is provided in the flow path 43. Heat exchange takes place in the heater core 53 between high-temperature coolant and air used for heating the vehicle interior.

[0028] The flow path 45 is connected to the multi-function valve 50 and the inlet 59, with an ATF cooler 55 provided in between. In the ATF cooler 55, heat exchange occurs between the ATF, which is used for the operation, lubrication, and cooling of the automatic transmission, and high-temperature coolant, thereby cooling the ATF.

[0029] As described above, the high-temperature coolant, after passing through the radiator 51, reserve tank 52, heater core 53, and ATF cooler 55, is supplied to the inlet 59. The high-temperature coolant supplied to the inlet 59 is then supplied back to the engine 1 by the water pump 57.

[0030] Figure 3 is a graph showing the opening ratios of the flow paths 41, 46, and 45, which are adjusted by the multi-function valve 50. The multi-function valve 50 has a rotatable rotor, and the opening ratio of each flow path is adjusted according to the rotational angle position of the rotor. Figure 3 shows the rotational angle range of the rotor, from angle αS to angle (-βS). The angle that serves as the reference angle for rotor rotation is set to angle 0 degrees.

[0031] At an angle of 0 degrees, channels 41, 46, and 45 are all fully closed. From angle α1 to angle α2, channel 46 changes from fully closed to fully open. From angle α3 to angle α4, channel 45 changes from fully closed to fully open. From angle α5 to angle α6, channel 41 changes from fully closed to fully open. From angle α6 to angle αS, channels 41, 46, and 45 are all fully open. From angle (-β1) to angle (-β2), channel 45 changes from fully closed to fully open. From angle (-β3) to angle (-β4), channel 41 changes from fully closed to fully open. From angle (-β4) to angle (-βS), channels 41 and 45 are fully open, and channel 46 is fully closed.

[0032] [Outline configuration of the low-temperature cooling circuit and the air conditioning circuit] Figure 4 is a schematic diagram of the low-temperature cooling circuit 60 and the air conditioning circuit 80. The low-temperature cooling circuit 60 includes an intercooler 6, a low-temperature radiator 71, a reserve tank 72, a water pump 77, and a chiller 90. The water pump 77 is an electrically operated pump controlled by the ECU 30. The water pump 77 causes the low-temperature coolant to flow through the passage 61 in the order of intercooler 6, low-temperature radiator 71, reserve tank 72, and chiller 90. Heat exchange occurs between the low-temperature coolant and the outside air in the low-temperature radiator 71, promoting heat dissipation of the low-temperature coolant. The passage 62 is connected between the water pump 77 and the chiller 90 in the passage 61, and between the passage 61, the intercooler 6, and the low-temperature radiator 71. A supercharger 5 is provided in the passage 62. The chiller 90 includes a first passage 94 that communicates with the passage 61. The chiller 90 will be described in more detail later. Furthermore, the low-temperature cooling water flowing through the low-temperature cooling circuit 60 is at a lower temperature than the high-temperature cooling water flowing through the high-temperature cooling circuit 40.

[0033] The air conditioning circuit 80 comprises a chiller 90, an evaporator 95, a compressor 96, and a condenser 97. The air conditioning circuit 80 constitutes a refrigeration cycle. The refrigerant for air conditioning flows through the flow path 81 in the order of chiller 90, evaporator 95, compressor 96, and condenser 97. The evaporator 95 evaporates the refrigerant by allowing it to absorb heat from the surrounding air. The compressor 96 adiabatically compresses the low-temperature, low-pressure, mainly gaseous refrigerant flowing from the evaporator 95, changing it into a high-temperature, high-pressure, mainly gaseous state. The condenser 97 condenses the refrigerant for air conditioning by exchanging heat with the outside air, changing it into a liquid state. The chiller 90 is a heat exchanger in which the refrigerant for air conditioning flowing inside the chiller 90 and the low-temperature cooling water flowing through the first passage 94 of the chiller 90 exchange heat. The refrigerant used for air conditioning flowing through the chiller 90 is colder than the low-temperature cooling water flowing through the chiller 90. As a result, the temperature of the low-temperature cooling water decreases, and the intercooler 6 and turbocharger 5 of the low-temperature cooling circuit 60 are cooled.

[0034] The chiller 90 includes, in addition to the first passage 94 described above, a second passage 91, a third passage 92, and a switching valve 93. The flow path 81 communicates with the second passage 91 and the third passage 92. Therefore, the refrigerant for air conditioning can flow through the second passage 91 and the third passage 92. The switching valve 93 is provided at the connection point between the second passage 91 and the third passage 92. The switching valve 93 is a solenoid valve that fully opens one of the second passages 91 and 92 and fully closes the other. The switching valve 93 is controlled by 30. The third passage 92 flows closer to the first passage 94 than the second passage 91. Therefore, when the refrigerant for air conditioning flows through the third passage 92, heat exchange with the low-temperature cooling water is promoted more than when it flows through the second passage 91, and the low-temperature cooling water becomes colder.

[0035] [Overheat suppression control] Next, we will explain the overheat suppression control performed by the ECU 30. Figure 5 is a flowchart illustrating the overheat suppression control performed by the ECU 30. The ECU 30 acquires the position information of the vehicle 100 using the method described above (step S1). Step S1 is an example of the processing performed by the acquisition unit.

[0036] Next, the ECU 30 predicts whether the high-load operation of engine 1 will continue for a predetermined time or longer based on the location information (step S2). For example, if the current location of vehicle 100 indicates a circuit or gymkhana course based on the location information, step S2 determines Yes. Also, if there is an uphill slope with a predetermined incline angle or greater within a predetermined range in the direction of travel from vehicle 100 for a predetermined distance or longer, step S2 also determines Yes. Here, the predetermined time is the time during which engine 1 may overheat due to continued high-load operation. If step S2 is No, this control terminates. Step S2 is an example of the processing performed by the prediction unit.

[0037] If the answer in step S2 is Yes, the ECU 30 performs a process to increase the radiator flow rate of engine 1 (step S3). The radiator flow rate increase process increases the flow rate of high-temperature coolant to the radiator 51 when the answer in step S2 is Yes compared to when the answer in step S2 is No. Specifically, the flow rate of high-temperature coolant to the radiator 51 is increased by adjusting the angle of the rotor of the multi-function valve 50 shown in Figure 3. For example, the rotor of the multi-function valve 50 is controlled between angles (-β4) and (-βS). As a result, passages 41 and 45 are fully open and passage 46 is fully closed. Therefore, high-temperature coolant flows to the radiator 51 and ATF cooler 55, but not to the heater core 53 and throttle water jacket 56. Figure 2 shows the state where high-temperature coolant flows to the radiator 51 and ATF cooler 55, but not to the heater core 53 and throttle water jacket 56. In this case, the flow rate of high-temperature coolant flowing to the radiator 51 is maximized. The radiator 51 maximizes the heat dissipation of the high-temperature coolant, improving the cooling performance of engine 1. As a result, overheating of engine 1 is suppressed.

[0038] Furthermore, while flow path 41 is fully open from angle α6 to angle αS, flow paths 45 and 46 are also fully open. For this reason, the flow rate of high-temperature coolant flowing to the radiator 51 is greater when the rotor of the multi-function valve 50 is controlled between angle (-β4) and angle (-βS). Step S3 is an example of a process performed by the flow control unit.

[0039] Next, the ECU 30 performs a heat exchange rate increase process (step S4). The heat exchange rate increase process increases the amount of heat exchanged between the refrigerant for air conditioning and the low-temperature coolant in the chiller 90 compared to when the answer to step S2 is No, if the answer to step S2 is Yes. Specifically, by controlling the switching valve 93 shown in Figure 4, the second passage 91 is completely closed and the third passage 92 is completely opened. As a result, the refrigerant for air conditioning flows closer to the first passage 94 through which the low-temperature coolant flows, increasing the amount of heat exchanged between the refrigerant for air conditioning and the low-temperature coolant. Figure 4 shows the state where the low-temperature coolant flows through the third passage 92 and not through the second passage 91. As a result, the low-temperature coolant becomes even colder, and the intercooler 6 and the supercharger 5 are sufficiently cooled. The temperature of the intake air supercharged by the supercharger 5 can be sufficiently lowered, improving the cooling performance of the engine 1. Therefore, overheating of the engine 1 is suppressed.

[0040] Next, the ECU30 performs ignition timing retardation (step S5). Ignition timing retardation is a process that advances the ignition timing of the spark plug 2b of engine 1 compared to when step S2 is No, if step S2 is Yes. Figure 6 is a graph showing the relationship between the ignition timing and the temperature of the high-temperature coolant immediately after it is discharged from engine 1. As shown in Figure 6, the further the ignition timing is advanced, the lower the temperature of the high-temperature coolant, that is, the lower the amount of heat generated by engine 1. Therefore, overheating of engine 1 is suppressed. Step S5 is an example of a process performed by the ignition timing control unit.

[0041] As described above, the above process is executed when it is predicted that the engine 1 will continue to operate under high load for a predetermined period of time or longer, based on the position information of the vehicle 100. This effectively suppresses overheating of the engine 1.

[0042] Vehicle 100 may be a hybrid vehicle equipped with an engine 1 and a motor as a power source for driving.

[0043] Although embodiments of the present invention have been described in detail above, the present invention is not limited to these specific embodiments, and various modifications and changes are possible within the scope of the gist of the present invention as described in the claims. [Explanation of symbols]

[0044] 1 Engine 2b Spark plug 5. Supercharger 6 Intercoolers 30 ECU (Vehicle control unit, acquisition unit, prediction unit, flow rate control unit, heat exchange amount control unit, ignition timing control unit) 51 Radiator 90 Chiller (heat exchanger) 91 2nd aisle 92 3rd aisle 93 Switching valve 94 1st aisle 100 vehicles

Claims

1. An acquisition unit that acquires location information of a vehicle equipped with an engine, A prediction unit predicts whether the high-load operation of the engine will continue for a predetermined time or longer based on the position information, A flow control unit that, when it is predicted that the high-load operation of the engine will continue for a predetermined time or longer, increases the flow rate of the high-temperature coolant flowing through the engine to the radiator compared to when it is not predicted that the high-load operation of the engine will continue for a predetermined time or longer, A vehicle control device equipped with the following features.

2. The vehicle control device according to claim 1, further comprising a heat exchange amount control unit that increases the amount of heat exchange between the air conditioning refrigerant and the low-temperature cooling water flowing through the intercooler and turbocharger of the engine in a heat exchanger through which the air conditioning refrigerant and the low-temperature cooling water flowing through the engine's intercooler and turbocharger flows, when it is predicted that the high-load operation of the engine will continue for a predetermined time or longer, compared to when it is not predicted that the high-load operation of the engine will continue for a predetermined time or longer.

3. The heat exchanger has a first passage through which the low-temperature cooling water flows, a second passage through which the refrigerant for air conditioning can flow, a third passage through which the refrigerant for air conditioning can flow and which is located closer to the first passage than the second passage, and a switching valve for flowing the refrigerant for air conditioning into the second passage or the third passage. The vehicle control device according to claim 2, wherein the heat exchange amount control unit controls the switching valve to flow the refrigerant for air conditioning into the second passage if it is not expected that the high-load operation of the engine will continue for a predetermined time or longer, and controls the switching valve to flow the refrigerant for air conditioning into the third passage to increase the amount of heat exchange if it is expected that the high-load operation of the engine will continue for a predetermined time or longer.

4. The vehicle control device according to claim 3, further comprising an ignition timing control unit that advances the ignition timing of the engine compared to when it is not expected that the high-load operation of the engine will continue for a predetermined time or longer, when it is predicted that the high-load operation of the engine will continue for a predetermined time or longer.

5. The vehicle control device according to any one of claims 1 to 4, wherein the prediction unit predicts that the engine will continue to operate under high load for a predetermined time or longer when the location information indicates that the vehicle is located on a circuit or gymkhana course.

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