JP2016211379A - Engine automatic stop restarting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an engine automatic stop restarting device capable making compatible the improvement in a fuel consumption and the improvement in the comfort of a cabin.SOLUTION: An engine automatic stop restarting device comprises: an outside air temperature sensor 54 for detecting the temperature of the outside air; a solar radiation sensor 52 for detecting the solar radiation of a vehicle 1; and an ECU 4 for setting a first set temperature and a second set temperature in accordance with the ambient temperature and the solar radiation thereby to inhibit the automatic stop of an engine 2 either in the case where the temperature of an evaporator core 31 is higher than a first set temperature, or in the case where the temperature of the cooling water of the engine 2 is lower than a second set temperature.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an engine automatic stop / restart device, and more particularly to an engine automatic stop / restart device that controls automatic engine stop / restart according to an air conditioning state.

  In recent years, for the purpose of improving fuel consumption, vehicles equipped with an idling stop function for automatically stopping or restarting an engine when a preset condition is satisfied have become widespread. In such a vehicle, if the engine is automatically stopped when air conditioning is used, the temperature of the evaporator rises due to the compressor stopping during cooling, and the engine coolant is heated in a heat source such as a heater core during heating. The temperature of the heat source is lowered by not circulating. Thereby, the comfort in a vehicle interior will deteriorate.

  In order to solve such a problem, Patent Document 1 proposes that the engine be restarted when the engine is automatically stopped and the temperature in the passenger compartment is out of a predetermined range.

  Further, in Patent Documents 2 and 3, the engine is restarted when the temperature of the air after passing the evaporator exceeds a predetermined temperature, or the engine is restarted when the temperature of the cooling water of the engine is lower than the predetermined temperature. It has been proposed to start.

Japanese Patent Laid-Open No. 11-44230 JP 2001-113940 A JP 2001-263123 A

  However, in such an engine automatic stop / restart device, since the threshold value for determining whether or not to restart the engine is a fixed value, it is possible to improve fuel efficiency and comfort in the passenger compartment. I couldn't make it compatible.

  For example, in the case of the air temperature after passing through the evaporator, if a high threshold is set to increase fuel efficiency, high cooling performance is required due to the environment around the vehicle, such as high outside air temperature or high solar radiation. In addition, the comfort in the passenger compartment deteriorated without the engine being restarted.

  In addition, if the threshold is set low to improve the comfort in the passenger compartment, the engine is restarted even when cooling performance is not required so much, the idling stop is not maintained, and the fuel consumption cannot be improved. .

  SUMMARY OF THE INVENTION An object of the present invention is to provide an engine automatic stop / restart device capable of achieving both improvement in fuel consumption and improvement in comfort in a vehicle compartment.

  One aspect of the invention of an engine automatic stop / restart device that solves the above problems is to stop the engine when a preset automatic stop condition is satisfied, and restart the engine when a preset restart condition is satisfied. A controller for starting the engine, the controller configured to start the engine when the temperature of the cooling heat exchanger exceeds the first set temperature or when the temperature of the engine coolant is less than the second set temperature. An engine automatic stop / restart device that prohibits an automatic stop, and includes an outside air temperature sensor that detects an outside air temperature and a solar radiation amount sensor that detects an amount of solar radiation, and the control unit detects the outside air detected by the outside air temperature sensor. The first set temperature and the second set temperature are set according to the temperature and the amount of solar radiation detected by the solar radiation amount sensor.

  As described above, according to one aspect of the present invention, it is possible to achieve both improvement in fuel consumption and improvement in the comfort of the passenger compartment.

FIG. 1 is a conceptual block diagram showing an engine automatic stop / restart device according to an embodiment of the present invention. FIG. 2 is a diagram showing an engine automatic stop / restart device according to an embodiment of the present invention, and is a diagram showing an example of a map for obtaining a threshold temperature of an automatic stop condition from the amount of solar radiation and the outside air temperature. FIG. 3 is a diagram illustrating an engine automatic stop / restart device according to an embodiment of the present invention, and is a diagram illustrating an example of a map for obtaining a threshold temperature of a restart condition from the amount of solar radiation and the outside air temperature. FIG. 4 is a diagram illustrating an engine automatic stop / restart device according to an embodiment of the present invention, and is a flowchart illustrating the idling stop control process. FIG. 5 is a diagram illustrating an engine automatic stop / restart device according to an embodiment of the present invention, and is a flowchart illustrating an automatic stop condition determination process based on the temperature of the evaporator core. FIG. 6 is a diagram illustrating an automatic engine stop / restart apparatus according to an embodiment of the present invention, and is a flowchart illustrating an automatic stop condition determination process based on the temperature of the engine coolant. FIG. 7 is a diagram illustrating an engine automatic stop / restart device according to an embodiment of the present invention, and is a flowchart illustrating a restart condition determination process based on the temperature of the evaporator core. FIG. 8 is a diagram illustrating an engine automatic stop / restart device according to an embodiment of the present invention, and is a flowchart illustrating a restart condition determination process based on the temperature of the engine coolant.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
In FIG. 1, a vehicle 1 equipped with an engine automatic stop / restart device according to an embodiment of the present invention includes an engine 2, an air conditioner 3, and an ECU 4 as a control unit.

  The engine 2 includes a four-cycle engine that performs a series of four strokes including an intake stroke, a compression stroke, an expansion stroke, and an exhaust stroke, and performs ignition by an ignition device (not shown) during the compression stroke and the expansion stroke. .

  The air conditioner 3 is an HVAC (Heating, Ventilating, and Air Conditioning) device that performs air conditioning such as heating, cooling, dehumidification, and ventilation of the vehicle 1 using the engine 2 as a travel drive source.

  The air conditioner 3 includes an outside air introduction port 20a that communicates the interior of the air conditioner 3 to the outside of the vehicle compartment, and an inside air introduction port 20b that communicates the interior of the air conditioner 3 to the interior of the vehicle interior. Is formed.

  The outside air introduction port 20a is an introduction port for introducing the air outside the passenger compartment into the air conditioner 3. The inside air introduction port 20b is an introduction port for introducing air in the vehicle interior into the air conditioner 3, that is, an introduction port for introducing air to be circulated in the vehicle interior.

  In the air conditioner 3, there is provided an introduction port switching door 21 for switching an introduction port for air to be blown into the vehicle interior between the outside air introduction port 20a and the inside air introduction port 20b. The introduction port switching door 21 moves between a position where the outside air introduction port 20a is completely closed and the inside air introduction port 20b is completely opened, and a position where the inside air introduction port 20b is completely closed and the outside air introduction port 20a is completely opened. The air conditioner 3 is rotatably mounted so as to be able to do so.

  The introduction port switching door 21 is provided with an actuator 22 for driving the introduction port switching door 21. The actuator 22 controls the position of the introduction port switching door 21 in accordance with control by the ECU 4.

  Further, the air conditioner 3 includes a defroster discharge port 24a communicated with a defroster discharge port opened toward the vehicle interior side of the front window glass as an air discharge port to be blown into the vehicle interior, and a driver seat and a passenger seat. The vent outlet 24b communicated with the vent outlet opened toward the vehicle and the foot outlet 24c communicated with the leg outlet opened toward the feet of the passenger seated in the driver's seat and the passenger seat are formed. Has been.

  In the air conditioner 3, an outlet switching door 25a for opening and closing the defroster outlet 24a and an outlet switching door 25b for selectively opening and closing the vent outlet 24b and the foot outlet 24c are provided.

  The air outlet switching door 25a is rotatably mounted in the air conditioner 3 so as to be movable between a position where the defroster discharge port 24a is completely closed and a position where the defroster discharge port 24a is fully opened.

  The blower outlet switching door 25a is provided with an actuator 26a for driving the blower outlet switching door 25a. The actuator 26a controls the position of the outlet switching door 25a in accordance with control by the ECU 4.

  The outlet switching door 25b moves between a position where the vent outlet 24b is completely closed and the foot outlet 24c is fully opened, and a position where the foot outlet 24c is completely closed and the vent outlet 24b is fully opened. The air conditioner 3 is rotatably mounted so as to be able to do so.

  The blower outlet switching door 25b is provided with an actuator 26b for driving the blower outlet switching door 25b. The actuator 26b controls the position of the outlet switching door 25b in accordance with control by the ECU 4.

  In the air conditioner 3, a blower fan 30, an evaporator core 31, an air mix door 32, and a heater core 33 are provided in order from the air inlet to the outlet.

  The blower fan 30 blows air that is blown into the passenger compartment. The blower fan 30 is provided with a blower fan motor 34 that rotates the blower fan 30. The blower fan 30 is rotated by a blower fan motor 34 to blow air introduced from the inlet toward the outlet. The rotational force of the blower fan motor 34 is changed in accordance with control by the ECU 4 to change the air flow rate of the blower fan 30.

  The evaporator core 31 cools the air passing through the evaporator core 31 by performing heat exchange between the air that passes so as to contact the surface of the evaporator core 31 and the refrigerant that expands and vaporizes in the evaporator core 31. And dehumidifying. The evaporator core 31 is provided with a compressor 35 that compresses the refrigerant, and a condenser 36 that cools the refrigerant compressed by the compressor 35. By controlling the on / off of the compressor 35, the air conditioner 3 A known cooling device is constructed. That is, the evaporator core 31 constitutes a cooling heat exchanger.

  The air mix door 32 adjusts the flow rate of air passing through the heater core 33. Specifically, the air mix door 32 can move between a position where the air passing through the evaporator core 31 passes through the heater core 33 and a position where the air passing through the evaporator core 31 does not pass through the heater core 33. The air conditioner 3 is rotatably mounted.

  The air mix door 32 is provided with an actuator 37 for driving the air mix door 32. The actuator 37 controls the position of the air mix door 32 (hereinafter also referred to as “air mix door opening”) in accordance with control by the ECU 4.

  The heater core 33 constitutes a heating heat exchanger that exchanges heat between the air cooled by the evaporator core 31 and the cooling water of the engine 2. Cooling water of the engine 2 is circulated through a circulation path 41 by a water pump 40 driven by the engine 2. The circulation path 41 is formed so that the cooling water circulates in the water jacket formed in the engine 2, the radiator 42, and the heater core 33. That is, the cooling water of the engine 2 constitutes a heat source for heating.

  Accordingly, the air conditioner 3 constitutes a heating device by controlling the position of the air mix door 32 so that the blower fan 30 is rotated and the air blown into the passenger compartment passes through the heater core 33.

  The ECU 4 includes a CPU (Central Processing Unit), a memory, and the like, and executes air conditioning control based on various input setting information and various detection information such as sensors in accordance with various control programs stored in the memory in advance.

  In the present embodiment, an evaporator temperature sensor 50 that detects the temperature of the evaporator core 31, a water temperature sensor 51 that detects the temperature of the cooling water of the engine 2, and the amount of solar radiation of the vehicle 1 are detected at the input port of the ECU 4. Various sensors including a solar radiation amount sensor 52, a vehicle interior temperature sensor 53 for detecting the temperature in the vehicle interior, and an outside air temperature sensor 54 for detecting the temperature of the outside air, and a control panel 55 are connected.

  The control panel 55 includes an air introduction mode selection switch in which an air inlet to be blown into the vehicle interior is selected between the outside air inlet 20a and the inside air inlet 20b, a defroster outlet, a vent outlet, and a foot outlet. A blower outlet mode selection switch for selecting a combination of ratios of the amount of air blown out from the air, an air volume adjustment switch for setting the flow rate of air blown out from these blowout openings (hereinafter also simply referred to as “blowout amount”), and setting Various controllers including a temperature setting switch for setting the temperature are provided. On the other hand, various control objects such as the actuators 22, 26 a, 26 b and 37, the blower fan motor 34 are connected to the output port of the ECU 4.

  For example, the ECU 4 detects the vehicle interior temperature detected by the vehicle interior temperature sensor 53 and the temperature set by the temperature setting switch of the control panel 55 when the air conditioner 3 is turned on by the air conditioning switch of the control panel 55. And the actuator 37 and the compressor 35 are appropriately controlled so that.

  Further, the ECU 4 controls an idling stop function that stops the engine 2 when a preset automatic stop condition is satisfied, and restarts the engine 2 when a preset restart condition is satisfied.

  As the automatic stop condition, for example, the vehicle speed is equal to or lower than a predetermined vehicle speed, the charge capacity of the battery is equal to or higher than a predetermined value, the temperature of the cooling water of the engine 2 is equal to or higher than a predetermined threshold, and the temperature of the evaporator core 31 Is that all of the above are established. On the other hand, as restart conditions, for example, the shift position is suitable for starting, the brake pedal is not depressed, the battery charge capacity is less than a predetermined value, and the cooling water temperature of the engine 2 is predetermined. It is a condition that any one or any combination, such as being less than a threshold value and the temperature of the evaporator core 31 exceeding a predetermined threshold value, has been established.

  The ECU 4 changes the threshold value of the automatic stop condition or the restart condition in accordance with the outside air temperature or the amount of solar radiation when determining the automatic stop condition or the restart condition depending on the temperature of the evaporator core 31.

  Further, the ECU 4 changes the threshold value of the automatic stop condition or the restart condition in accordance with the outside air temperature or the amount of solar radiation in the determination of the automatic stop condition or the restart condition based on the coolant temperature of the engine 2.

  The memory of the ECU 4 stores a map for determining a first set temperature that is a threshold value of the temperature of the evaporator core 31 under automatic stop conditions from the amount of solar radiation and the outside air temperature, as shown in FIG.

  When determining the temperature of the evaporator core 31 as the automatic stop condition, the ECU 4 prohibits the automatic stop of the engine 2 if it is higher than the first set temperature obtained from the solar radiation amount and the outside air temperature by the map of FIG. .

  2A is set to a lower temperature as the outside air temperature is higher, and a lower temperature is set as the amount of solar radiation is larger. That is, α1 ≧ α2 ≧ α3 ≧ α4 ≧ α5 and α1 ≧ α6 ≧ α11.

  Further, the memory of the ECU 4 stores a map for determining a second set temperature as a threshold value of the coolant temperature of the engine 2 under the automatic stop condition from the amount of solar radiation and the outside air temperature as shown in FIG. ing.

  When the ECU 4 determines the coolant temperature of the engine 2 as an automatic stop condition, the ECU 4 automatically stops the engine 2 if it is lower than the second set temperature obtained from the solar radiation amount and the outside air temperature by the map of FIG. Ban.

  2B, the lower the temperature is set as the outside air temperature is higher, and the lower the temperature is set as the amount of solar radiation is larger. That is, β1 ≧ β2 ≧ β3 ≧ β4 ≧ β5 and β1 ≧ β6 ≧ β11.

  The memory of the ECU 4 stores a map for determining a third set temperature that is a threshold value of the temperature of the evaporator core 31 under the restart condition from the amount of solar radiation and the outside air temperature, as shown in FIG.

  When the ECU 4 determines the temperature of the evaporator core 31 as the restart condition, the engine according to the temperature of the evaporator core 31 if the temperature is equal to or lower than the third set temperature obtained from the solar radiation amount and the outside air temperature by the map of FIG. Suppose that the restart condition 2 is not satisfied.

  In addition, as for the value of the map of FIG. 3A, a lower temperature is set as the outside air temperature is higher, and a lower temperature is set as the amount of solar radiation is larger. That is, γ1 ≧ γ2 ≧ γ3 ≧ γ4 ≧ γ5, and γ1 ≧ γ6 ≧ γ11.

  Here, a temperature higher than the value of the map of FIG. 2A is set as the value of the map of FIG. That is, γ1> α1, γ2> α2, γ3> α3, γ4> α4, and γ5> α5.

  Further, the memory of the ECU 4 stores a map in which a fourth set temperature, which is a threshold value of the coolant temperature of the engine 2 under the restart condition, is determined from the amount of solar radiation and the outside air temperature as shown in FIG. ing.

  When the ECU 4 determines the coolant temperature of the engine 2 as the restart condition, the ECU 4 depends on the coolant temperature if the temperature is equal to or higher than the fourth set temperature obtained from the solar radiation amount and the outside air temperature according to the map of FIG. Assume that the restart condition of the engine 2 is not satisfied.

  In addition, as for the value of the map of FIG. 3B, a lower temperature is set as the outside air temperature is higher, and a lower temperature is set as the amount of solar radiation is larger. That is, δ1 ≧ δ2 ≧ δ3 ≧ δ4 ≧ δ5 and δ1 ≧ δ6 ≧ δ11.

  Here, a temperature lower than the value of the map of FIG. 2B is set as the value of the map of FIG. That is, δ1 <β1, δ2 <β2, δ3 <β3, δ4 <β4, and δ5 <β5.

  The idling stop control process by the engine automatic stop / restart apparatus according to the present embodiment configured as described above will be described with reference to FIG. In the present embodiment, the determination based on the cooling water temperature of the engine 2 or the determination based on the temperature of the evaporator core 31 in the automatic stop condition or the restart condition described above is executed at predetermined time intervals in each part of the ECU 4. The determination result can be referred to as automatic stop determination information and restart determination information. In the automatic stop determination information, automatic stop prohibition or automatic stop permission is set for each determination. In the restart determination information, whether the restart condition is not satisfied or the restart condition is satisfied is set for each determination.

  The idling stop control process described below is started when the operation of the ECU 4 starts and is executed at a preset time interval.

  First, the ECU 4 acquires automatic stop determination information (step S1), and determines whether or not an automatic stop condition for the engine 2 is satisfied (step S2). When it is determined that the automatic stop condition for the engine 2 is not satisfied, the ECU 4 ends the idling stop control process.

  On the other hand, when it is determined that the automatic stop condition of the engine 2 is satisfied, the ECU 4 automatically stops the engine 2 by stopping the fuel injection of the engine 2 (step S3).

  Thereafter, the ECU 4 acquires restart determination information (step S4), and determines whether or not a restart condition for the engine 2 is satisfied (step S5). When it is determined that the restart condition of the engine 2 is not satisfied, the ECU 4 returns to step S4, acquires restart determination information, and repeats the determination of the restart condition.

  On the other hand, when it is determined that the restart condition of the engine 2 is satisfied, the ECU 4 restarts the engine 2 (step S6) and ends the idling stop control process.

  Next, the automatic stop condition determination process for the engine 2 based on the temperature of the evaporator core 31 will be described with reference to FIG. Note that the automatic stop condition determination process of the engine 2 based on the temperature of the evaporator core 31 described below is started when the operation of the ECU 4 starts and is executed at a preset time interval.

  First, the ECU 4 acquires the temperature of the evaporator core 31 by using the evaporator temperature sensor 50 (step S11). Next, the ECU 4 acquires the outside air temperature by the outside air temperature sensor 54 and acquires the amount of solar radiation by the solar radiation amount sensor 52 (step S12). Then, the ECU 4 acquires the first set temperature from the outside air temperature and the amount of solar radiation using a map as shown in FIG. 2A (step S13).

  Next, the ECU 4 determines whether or not the temperature of the evaporator core 31 is higher than the first set temperature (step S14). When it is determined that the temperature of the evaporator core 31 is higher than the first set temperature, the ECU 4 sets automatic stop prohibition in the automatic stop determination information based on the temperature of the evaporator core 31 (step S15).

  On the other hand, when it is determined that the temperature of the evaporator core 31 is not higher than the first set temperature, the ECU 4 sets automatic stop permission in the automatic stop determination information based on the temperature of the evaporator core 31 (step S16).

  Next, the automatic stop condition determination process for the engine 2 based on the coolant temperature of the engine 2 will be described with reference to FIG. The automatic stop condition determination process for the engine 2 based on the coolant temperature of the engine 2 described below is started when the operation of the ECU 4 is started, and is executed at a preset time interval.

  First, ECU4 acquires the temperature of the cooling water of the engine 2 by the water temperature sensor 51 (step S21). Next, the ECU 4 acquires the outside air temperature by the outside air temperature sensor 54 and acquires the amount of solar radiation by the solar radiation amount sensor 52 (step S22). Then, the ECU 4 acquires the second set temperature from the outside air temperature and the amount of solar radiation using a map as shown in FIG. 2B (step S23).

  Next, the ECU 4 determines whether or not the cooling water temperature of the engine 2 is lower than the second set temperature (step S24). When it is determined that the coolant temperature of the engine 2 is lower than the second set temperature, the ECU 4 sets automatic stop prohibition in the automatic stop determination information based on the coolant temperature of the engine 2 (step S25).

  On the other hand, when it determines with the temperature of the cooling water of the engine 2 not being lower than 2nd setting temperature, ECU4 sets automatic stop permission to the automatic stop determination information by the temperature of the cooling water of the engine 2 (step S26).

  Next, the restart condition determination process of the engine 2 based on the temperature of the evaporator core 31 will be described with reference to FIG. Note that the restart condition determination process of the engine 2 based on the temperature of the evaporator core 31 described below is started when the operation of the ECU 4 starts and is executed at a preset time interval.

  First, the ECU 4 acquires the temperature of the evaporator core 31 by using the evaporator temperature sensor 50 (step S31). Next, the ECU 4 acquires the outside air temperature by the outside air temperature sensor 54 and acquires the amount of solar radiation by the solar radiation amount sensor 52 (step S32). Then, the ECU 4 acquires the third set temperature from the outside air temperature and the amount of solar radiation using a map as shown in FIG. 3A (step S33).

  Next, the ECU 4 determines whether or not the temperature of the evaporator core 31 is equal to or lower than the third set temperature (step S34). When it is determined that the temperature of the evaporator core 31 is equal to or lower than the third set temperature, the ECU 4 sets the restart condition not satisfied in the restart determination information based on the temperature of the evaporator core 31 (step S35).

  On the other hand, when it is determined that the temperature of the evaporator core 31 is not equal to or lower than the third set temperature, the ECU 4 sets the restart condition to be satisfied in the restart determination information based on the temperature of the evaporator core 31 (step S36).

  Next, the restart condition determination process of the engine 2 based on the temperature of the cooling water of the engine 2 will be described with reference to FIG. The engine 2 restart condition determination process based on the coolant temperature of the engine 2 described below is started when the operation of the ECU 4 is started, and is executed at a preset time interval.

  First, ECU4 acquires the temperature of the cooling water of the engine 2 by the water temperature sensor 51 (step S41). Next, the ECU 4 acquires the outside air temperature by the outside air temperature sensor 54 and acquires the amount of solar radiation by the solar radiation amount sensor 52 (step S42). Then, the ECU 4 acquires the fourth set temperature from the outside air temperature and the amount of solar radiation using a map as shown in FIG. 3B (step S43).

  Next, the ECU 4 determines whether or not the coolant temperature of the engine 2 is equal to or higher than a fourth set temperature (step S44). When it is determined that the coolant temperature of the engine 2 is equal to or higher than the fourth set temperature, the ECU 4 sets the restart condition not established in the restart determination information based on the coolant temperature of the engine 2 (step S45).

  On the other hand, when it is determined that the temperature of the cooling water of the engine 2 is not equal to or higher than the fourth set temperature, the ECU 4 sets the restart condition to the restart determination information based on the temperature of the cooling water of the engine 2 (step S46).

  Thus, in the above-described embodiment, the outside air temperature sensor 54 that detects the temperature of the outside air, the solar radiation amount sensor 52 that detects the solar radiation amount of the vehicle 1, and the first set temperature according to the outdoor air temperature and the solar radiation amount. When the temperature of the evaporator core 31 exceeds the first set temperature, or when the temperature of the cooling water of the engine 2 is lower than the second set temperature, the engine 2 is automatically stopped. ECU4 which prohibits.

  Thereby, the threshold value which performs the determination which prohibits an automatic stop according to the outside temperature and the amount of solar radiation is set. For this reason, automatic stop is prohibited according to the outside air temperature and the amount of solar radiation, and it is possible to achieve both improvement in fuel efficiency and improvement in the comfort of the passenger compartment.

  The first set temperature is set lower as the outside air temperature is higher. As a result, as the outside air temperature is higher and the cooling performance is required, the automatic stop of the engine 2 is prohibited in a state where the temperature of the evaporator core 31 is low, and both improvement in fuel consumption and improvement in comfort in the vehicle interior can be achieved. it can.

  The first set temperature is set lower as the amount of solar radiation is larger. As a result, as the amount of solar radiation increases and the cooling performance is required, the automatic stop of the engine 2 is prohibited in a state where the temperature of the evaporator core 31 is low, and it is possible to achieve both improvement in fuel efficiency and improvement in vehicle interior comfort. it can.

  The second set temperature is set lower as the outside air temperature is higher. As a result, as the outside air temperature is lower and the heating performance is required, automatic stop of the engine 2 is prohibited while the cooling water temperature of the engine 2 is high, and both improvement in fuel efficiency and improvement in vehicle interior comfort are achieved. be able to.

  The second set temperature is set lower as the amount of solar radiation is larger. As a result, as the amount of solar radiation is small and heating performance is required, automatic stop of the engine 2 is prohibited in a state where the cooling water of the engine 2 is high, and both improvement in fuel efficiency and improvement in vehicle interior comfort are achieved. be able to.

  While embodiments of the invention have been disclosed, it will be apparent to those skilled in the art that changes may be made without departing from the scope of the invention. All such modifications and equivalents are intended to be included in the following claims.

DESCRIPTION OF SYMBOLS 1 Vehicle 2 Engine 3 Air conditioner 4 ECU (control part)
31 Evaporator core (cooling heat exchanger)
33 Heater core 50 Evaporator temperature sensor 51 Water temperature sensor 52 Solar radiation sensor 54 Outside air temperature sensor

Claims (5)

A controller that stops the engine when a preset automatic stop condition is satisfied, and restarts the engine when a preset restart condition is satisfied;
The controller prohibits the automatic stop of the engine when the temperature of the cooling heat exchanger exceeds the first set temperature or when the temperature of the cooling water of the engine is lower than the second set temperature. An engine automatic stop / restart device that performs
An outside temperature sensor for detecting the outside temperature;
A solar radiation sensor for detecting solar radiation,
The control unit sets the first set temperature and the second set temperature according to the outside air temperature detected by the outside air temperature sensor and the amount of solar radiation detected by the solar radiation amount sensor. Stop restart device.   The engine automatic stop / restart device according to claim 1, wherein the control unit sets the first set temperature to be lower as the outside air temperature is higher.   The engine automatic stop / restart device according to claim 1, wherein the control unit sets the first set temperature to be lower as the amount of solar radiation is larger.   The engine automatic stop / restart device according to claim 1, wherein the control unit sets the second set temperature to be lower as the outside air temperature is higher.   The engine automatic stop / restart device according to claim 1, wherein the control unit sets the second set temperature to be lower as the amount of solar radiation is larger.

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